CELL-SPECIFIC ADENOVIRUS VECTORS COMPRISING AN INTERNAL RIBOSOME ENTRY SITE

Abstract: Disclosed herein are replication-competent adenovirus vectors comprising co-transcribed first and second genes under transcriptional control of a heterologous, target cell-specific transcriptional regulatory element (TRE), wherein the second gene is under translational control of an internal ribosome entry site. Methods for the preparation and use of such vectors are also provided. The vectors provide target cell-specific virus replication in applications such as cancer therapy and gene therapy.

Description: CELL-SPECIFIC ADENOVIRUS VECTORS COMPRISING AN INTERNAL RIBOSOME ENTRY SITE TECHNICAL FIELD This invention relates to new replication competent adenovirus vectors comprising an internal ribosome entry site which replicate preferentially in target cells. The present invention also relates to cell transduction using adenovirus vectors comprising an internal ribosome entry site. BACKGROUND Diseases involving altered cell proliferation, particularly hyperproliferation, constitute an important health problem. For example, despite numerous advances in medical research, cancer remains the second leading cause of death in the United States. In the industrialized nations, roughly one in five persons will die of cancer. Traditional modes of clinical care, such as surgical resection, radiotherapy and chemotherapy, have a significant failure rate, especially for solid tumors. Neoplasia resulting in benign tumors can usually be completely cured by surgical removal ofthe tumor mass. If a tumor becomes malignant, as manifested by invasion of surrounding tissue, it becomes much more difficult to eradicate. Once a malignant tumor metastasizes, it is much less likely to be eradicated. Excluding basal cell carcinoma, there are over one million new cases of cancer per year in the United States alone, and cancer accounts for over one half million deaths per year in this country. In the world as a whole, the five most common cancers are those of lung, stomach, breast, colon/rectum, and uterine cervix, and the total number of new cases per year is over 6 million. In the United States, transitional cell carcinoma (TCC) accounts for 90 to 95 percent of all tumors ofthe bladder. Squamous cell carcinoma (SCC) represents 5 to 10 percent, and adenocarcinoma approximately 1 to 2 percent. Squamous cell and adenomatous elements are often found in association with transitional cell tumors, especially with high grade tumors. Bladder cancer is generally divided into superficial and invasive disease. A critical factor is the distinction between those tumors that are confined to the mucosa and those that have penetrated the basement membrane and extended into the lamina propria. The term "superficial bladder tumor" is generally used to represent a tumor that has not invaded the muscularis. Invasive tumors are described as those that have invaded the muscularis propria, the perivesical fibroadipose tissue, or adjacent structures. Carcinoma in situ (CIS) is a high grade and aggressive manifestation of TCC ofthe bladder that has a highly variable course. A number of urothelial cell-specific proteins have been described, among which are the uroplakins. Uroplakins (UP), including UPIa and UPIb (27 and 28 kDa, respectively), UPII (15 kDa), and UPIII (47 kDa), are members of a group of integral membrane proteins that are major proteins of urothelial plaques. These plaques cover a large portion ofthe apical surface of mammalian urothelium and may play a role as a permeability barrier and/or as a physical stabilizer ofthe urothelial apical surface. Wu et al. (1994) J. Biol. Chem. 269:13716-13724. UPs are bladder-specific proteins, and are expressed on a significant proportion of urothelial-derived tumors, including about 88% of transitional cell carcinomas. Moll et al. (1995) Am. J. Pathol. 147:1383-1397; and Wu et al. (1998) Cancer Res. 58 : 1291 - 1297. The control of the expression of the human UPII has been studied, and a 3.6-kb region upstream ofthe mouse UPII gene has been identified which can confer urothelial-specific transcription on heterologous genes (Lin et al. (1995) Proc. Natl. Acad. Sci. USA 92:679-683). See also, U.S. Patent Nos. 5,824,543 and 6,001,646. Melanoma, a malignant neoplasm derived from melanocytes ofthe skin and other sites, has been increasing in incidence worldwide. The American Joint Committee on Cancer recognizes five different forms of extraocular melanoma occurring in humans: lentigo maligna melanoma; radial spreading; nodular; acral lentiginous; and unclassified. Known melanoma-associated antigens can be classified into three main groups: tumor- associated testis-specific antigens MAGE, BAGE, GAGE, and PRAME; melanocyte differentiation antigens tyrosinase, Melan-A/MART-1 (for Melanoma Antigen Recognized by T cells), gplOO, tyrosinase related protein- 1(TRP-1), tyrosinase related protein-2 (TRP- 2); and mutated or aberrantly expressed antigens MUM-1, cyclin-dependent kinase 4 (CDK4), beta-catenin, gpl00-in4, pl5, and N-acetylglucosaminyltransferase V. See, for example, Kirkin et al. (1998) Exp. Clin. Immunogenet. 15:19-32. Tyrosinase, TRP-1, and TRP-2 are enzymes involved in melanin biosynthesis and are specifically expressed in melanocytes. Antigenic epitopes of MART-1 have been studied extensively, with the aim of developing a melanoma vaccine. An immunodominant epitope, MART- 1(27-35) has been reported to be recognized by a majority of CD 8+ cytotoxic T cell clones generated to MART-1. These MART-1 (27-35)-specific CTLs specifically lyse autologous tumor cell lines expressing the epitope. Faure and Kourilsky (1998) Crit. Rev. Immunol 18:77-86. However, others have reported that presence of such CTLs is not accompanied by a significant clinical response. Rivoltini et al. (1998) Crit. Rev. Immunol. 18:55-63. A major, indeed the overwhelming, obstacle to cancer therapy is the problem of selectivity; that is, the ability to inhibit the multiplication of tumor cells without affecting the functions of normal cells. For example, in traditional chemotherapy of prostate cancer, the therapeutic ratio, {i.e., the ratio of tumor cell killing to normal cell killing) is only 1.5:1. Thus, more effective treatment methods and pharmaceutical compositions for therapy and prophylaxis of neoplasia are needed. Accordingly, the development of more specific, targeted forms of cancer therapy, especially for cancers that are difficult to treat successfully, is of particular interest. In contrast to conventional cancer therapies, which result in relatively non-specific and often serious toxicity, more specific treatment modalities, which inhibit or kill malignant cells selectively while leaving healthy cells intact, are required. Gene therapy, whereby a gene of interest is introduced into a malignant cell, has been attempted as an approach to treatment of many cancers. See, for example, Boulikas ( 1997) Anticancer Res. 17: 1471 - 1505, for a description of gene therapy for prostate cancer. A gene of interest can encode a protein which is converted into a toxic substance upon treatment with another compound, or it can encode an enzyme that converts a prodrug to a drug. For example, introduction ofthe herpes simplex virus gene encoding thymidine kinase (HSN-tk) renders cells conditionally sensitive to ganciclovir. Zjilstra et al. (1989) Nature 342: 435; Mansour et al. (1988) Nature 336: 348; Johnson et al. (1989) Science 245: 1234; Adair etal. (1989) Proc. Natl. Acad. Sci. USA 86: 4574; Capecchi (1989) Science 244: 1288. Alternatively, a gene of interest can encode a compound that is directly toxic, such as, for example, diphtheria toxin. To render these treatments specific to cancer cells, the gene of interest is placed under control of a transcriptional regulatory element (TRE) that is specifically {i.e., preferentially) active in the cancer cells. Cell- or tissue- specific expression can be achieved by using a TRE with cell-specific enhancers and/or promoters. See generally Huber et al. (1995) Adv. Drug Delivery Reviews 17:279-292. A number of viral vectors and non- viral delivery systems {e.g., liposomes), have been developed for gene transfer. Ofthe viruses proposed for gene transfer, adeno viruses are among the most easily produced and purified. Adenovirus also has the advantage of a high efficiency of transduction {i.e., introduction ofthe gene of interest into the target cell) and does not require cell proliferation for efficient transduction. In addition, adenovirus can infect a wide variety of cells in vitro and in vivo. For general background references regarding adenovirus and development of adenoviral vector systems, see Graham et al. (1973) Virology 52:456-467; Takiff et al. (1981) Lancet 11 :832-834; Berkner et al. (1983) Nucleic Acid Research 11: 6003-6020; Graham (1984) EMBO J 3:2911 -2922; Bett et α/. (1993) J. Virology 67:5911-5921 ; and Bett et al. (1994) Proc. Natl. Acad. Sci. USA 91:8802-8806. Adenoviruses generally undergo a lyric replication cycle following infection of a host cell. In addition to lysing the infected cell, the replicative process of adenovims blocks the transport and translation host cell mRNA, thus inhibiting cellular protein synthesis. For a review of adenoviruses and adenovims replication, see Shenk, T. and Horwitz, M.S., Virology, third edition, Fields, B.N. et al, eds., Raven Press Limited, New York (1996), Chapters 67 and 68, respectively. When used for gene transfer, adenovims vectors are often designed to be replication-defective and are thus deliberately engineered to fail to replicate in the target cell. In these vectors, the early adenovims gene products EIA and/or EIB are often deleted, and the gene to be transduced is commonly inserted into the El A and/or EIB region ofthe deleted vims genome. Bett et al. (1994) supra. Such vectors are propagated in packaging cell lines such as the 293 line, which provides EIA and EIB functions in trans. Graham etal. (1987) J Gen. Virol 36:59-12; Graham (1977) J Gen. Virol. 68:937- 940. The use of replication-defective adenovims vectors as vehicles for efficient transduction of genes has been described by, inter alia, Stratford-Perricaudet (1990) Human Gene Therapy 1:241-256; Rosenfeld (1991) Science 252:431-434; Wang et al. (1991) Adv. Exp. Med. Biol. 309:61-66; Jaffe et al. (1992) Nature Gen. 1 :372-378; Quantin et α . (1992) Proc. Natl. Acad. Sci. USA 89:2581-2584; Rosenfeld et al. (1992) Cell 68:143-155; Stratford-Perricaudet et al. (1992) J. Clin. Invest. 90:626-630; Le Gal Le Salle et al. (1993) Science 259:988-990; Mastrangeli et al. (1993) J. Clin. Invest. 91:225-234; Ragot et α/. (1993) Nature 361:647-650; Hayaski et /. (1994) J. Biol. Chem. 269:23872-23875; and Bett et al. (1994) supra. In the treatment of cancer by replication-defective adenoviruses, the host immune response limits the duration of repeat doses at two levels. First, the capsid proteins ofthe adenovirus delivery vehicle itself are immunogenic. Second, viral late genes are frequently expressed in transduced cells, eliciting cellular immunity. Thus, the ability to repeatedly administer cytokines, tumor suppressor genes, ribozymes, suicide genes, or genes which convert a prodrug to an active drug has been limited by the immunogenicity of both the gene transfer vehicle and the viral gene products ofthe transfer vehicle, coupled with the transient nature of gene expression. Despite these limitations, development of adenoviral vectors for gene therapy has focused almost exclusively on the use ofthe vims as a vehicle for introducing a gene of interest, not as an effector in itself. In fact, replication of adenovims vectors has been viewed as an undesirable result, largely due to the host immune response. More recently, however, the use of adenovims vectors as effectors has been described. International Patent Application Nos. PCT/US98/04080, PCT/US98/04084, PCT/US98/04133, PCT/US98/04132, PCT/US98/16312, PCT/US95/00845, PCT/US96/10838, PCT/EP98/07380 and U.S. Pat. No. 5,998,205. Adenovims EIA and EIB genes are disclosed in Rao et al. (1992, Proc. Natl Acad. Sci. USA vol. 89: 7742- 7746). Replication-competent adenovims vectors, which take advantage ofthe cytotoxic effects associated with adenovims replication, have recently been described as agents for effecting selective cell growth inhibition. In such systems, a cell-specific transcriptional regulatory element (TRE) is used to control the expression of a gene essential for viral replication, thus limiting viral replication to cells in which the TRE is functional. See, for example International Patent Application No. PCT/EP99/07380, Henderson et al, U.S. Patent No. 5,698,443; Hallenbeck et al, PCT/US95/15455 and U.S. Patent No. 5,998,205; Rodriguez et al. (1997) Cancer Res. 57:2559-2563. PCT publication PCT/US98/04080 discloses replication-competent, target cell- specific adenovims vectors comprising heterologous TREs, such as those regulating expression of prostate-specific antigen (PSA), probasin (PB), α-fetoprotein (AFP), kallikrien ιKLK2), mucin {MUC1) and carcinoembryonic antigen (CEA). PCT US98/04084 discloses replication-competent adenovims vectors comprising an α-fetoprotein (AFP) TRE that replicate specifically in cells expressing AFP, such as hepatoma cells. Internal ribosome entry sites (IRES) are sequences which initiate translation from an internal initiation codon (usually AUG) within a bi-or multi- cistronic RNA transcript continuing multiple protein coding regions. IRES have been characterized in encephalomyocarditis vims and related picornaviruses. See, for example, Jackson et al. (1995) SNA 1: 985-1000 and Herman (1989) Trends in Biochemical Sciences 14(6): 219- 222. IRES sequences are also detected in mRNAs from other vimses such as cardiovirus, rhinovims, aphthovims, hepatitis C vims (HCN), Friend murine leukemia vims (FrMLN) and Moloney murine leukemia vims (MoMLV). The presence of IRES in cellular RΝAs has also been described. Examples of cellular mRΝAs containing IRES include those encoding immunoglobulin heavy-chain binding protein (BiP), vascular endothelial growth factor (VEGF), fibroblast growth factor 2, insulin-like growth factor, translational initiation factor eIF4G, and the yeast transcription factors TFIID and HAP4. See, for example, ; Macejak etfl/. (1991) Nature 353:90-94; Oh et al. (1992) Genes Dev. 6:1643-1653; Nagner et al. (1995) Mol Cell. Biol. 15:35-44; He et al. (1996) Proc. Natl. Acad. Sci USA 93:7274-7278; He et al. (1996) Gene 175:121-125; Tomanin etα/. (1997) Gene 193:129- 140; Gambotto et al. (1999) Cancer Gene Therapy 6:45-53; Qiao etal. (1999) Cancer Gene Therapy 6:373-379. Expression vectors containing IRES elements have been described. See, for example, International Patent Application No. PCT/US98/03699 and International Patent Application No. PCT/EP98/07380. Thus, there is a continuing need for improved replication-competent adenovims vectors in which cell-specific replication can be further enhanced, while minimizing the extent of replication in non-target ( . e. , non-cancerous cells). The disclosure of all patents and publications cited herein are incorporated by reference in their entirety. SUMMARY OF THE INVENTION The present invention provides improved replication competent adenovims vectors comprising co-transcribed first and second genes under transcriptional control of a heterologous, target cell-specific transcriptional regulatory element (TRE), wherein the second gene is under translational control of an internal ribosome entry site (IRES). In one embodiment, the first and second genes are co-transcribed as a single mRNA and the second gene has a mutation in or deletion of its endogenous promoter. The present invention further provides host cells and methods using the adenovims vectors. In one aspect, the first and/or second genes are adenovims genes and in another aspect, the first and/or second adenovims genes are essential for viral replication. An essential gene can be an early viral gene, including for example, EIA; EIB; E2; and/or E4, or a late viral gene. In another aspect an early gene is E3. In one embodiment, the first gene is an adenovims gene and the second gene is a therapeutic gene. In another embodiment, both genes are adenovims genes. In an additional embodiment, the first adenovims gene is El A, and the second adenovims gene is EIB. Optionally, the endogenous promoter for one ofthe co-transcribed adenovims gene essential for viral replication, such as for example, El A, is deleted and/or mutated such that the gene is under sole transcriptional control of a target cell-specific TRE. In another aspect, the present invention provides adenovims vectors comprising an adenovims gene essential for viral replication under control of a target cell-specific TRE, wherein said adenovims gene has a mutation of or deletion in its endogenous promoter. In one embodiment, the adenovims gene is essential for viral replication. In another embodiment, the adenovims gene is El A wherein the EIA promoter is deleted and wherein the EIA gene is under transcriptional control of a heterologous cell-specific TRE. In another embodiment, the adenovims gene is EIB wherein the EIB promoter is deleted and wherein the EIB gene is under transcriptional control of a heterologous cell-specific TRE. In another aspect, the present invention provides adenovims vectors comprising EIB under control of a target cell-specific TRE, wherein said EIB has a deletion in or mutation ofthe 19-kDa region of EIB, that encodes a product shown to inhibit apoptosis. In other embodiments, an enhancer element for the first and/or second adenovims genes is inactivated. The present invention provides an adenovims vector comprising EIA wherein an El A enhancer is inactivated. In yet other embodiments, the present invention provides an adenovims vector comprising EIA wherein the El A promoter is inactivated and EIA enhancer I is inactivated. In further embodiments, the present invention provides an adenovims vector comprising a TRE which has its endogenous silencer element inactivated. Any TRE which directs cell-specific expression can be used in the disclosed vectors. In one embodiment, TREs include, for example, TREs specific for prostate cancer cells, breast cancer cells, hepatoma cells, melanoma cells, bladder cells and/or colon cancer cells. In another embodiment, the TREs include, probasin (PB) TRE; prostate-specific antigen (PSA) TRE; mucin {MUCl) TRE; α-fetoprotein (AFP) TRE; hKLK2 TRE; tyrosinase TRE; human uroplakin II TRE (hUPII) and carcinoembryonic antigen (CEA) TRE. In other embodiments, the target cell-specific TRE is a cell status-specific TRE. In yet other embodiments, the target cell-specific TRE is a tissue specific TRE. In additional embodiments, the adenovims vector comprises at least one additional co-transcribed gene under the control ofthe cell-specific TRE. In another embodiment, an additional co-transcribed gene is under the translational control of an IRES. In another aspect ofthe present invention, adenovims vectors further comprise a transgene such as, for example, a cytotoxic gene. In one embodiment, the transgene is under the transcriptional control ofthe same TRE as the first gene and second genes and optionally under the translational control of an internal ribosome entry site. In another embodiment, the transgene is under the transcriptional control of a different TRE that is functional in the same cell as the TRE regulating transcription ofthe first and second genes and optionally under the translational control of an IRES. The present invention also provides compositions comprising the replication- competent adenovims vectors described herein. In one embodiment, the compositions further comprise a pharmaceutically acceptable excipient. The present invention also provides kits comprising the replication-competent adnenoviras vectors described herein. Host cells comprising the disclosed adenovims vectors are also provided. Host cells include those used for propagation of a vector and those into which a vector is introduced for therapeutic purposes. In another aspect, methods are provided for propagating replication-competent adenovims vectors ofthe present invention specific for mammalian cells which permit the function of a target cell-specific TRE, said method comprising combining an adenovims vector(s) described herein with mammalian cells that permit the function of a target cell- specific TRE, such that the adenovims vector(s) enters the cell, whereby said adenovims is propagated. In another aspect, methods are provided for conferring selective cytotoxicity in target cells, comprising contacting the cells with an adenovims vector(s) described herein, whereby the vector enters the cell. The invention further provides methods of suppressing tumor cell growth, more particularly a target tumor cell, comprising contacting a tumor cell with an adenovims vector(s) ofthe invention such that the adenovims vector enters the tumor cell and exhibits selective cytotoxicity for the tumor cell. In another aspect, methods are provided for detecting a cell which allows the function of a target cell-specific TRE, which comprise contacting a cell in a biological sample with an adenovims vector(s) ofthe invention, and detecting replication ofthe adenovims vector(s), if any. In another aspect, methods are provided for modifying the genotype of a target cell, comprising contacting the cell with an adenovims vector as described herein, wherein the adenovims vector enters the cell. The present invention provides an adenovims vector comprising an adenovims gene, wherein said adenovims gene is under transcriptional control of a melanocyte- specific TRE. In another embodiment, a melanocyte-specific TRE is human. In another embodiment, a melanocyte-specific TRE comprises a melanocyte-specific promoter and a heterologous enhancer. In other embodiments, a melanocyte-specific TRE comprises a melanocyte-specific promoter. In other embodiments, a melanocyte-specific TRE comprises a melanocyte-specific enhancer and a heterologous promoter. In other embodiments, a melanocyte-specific TRE comprises a melanocyte-specific promoter and a melanocyte-specific enhancer. In some embodiments, the adenovims gene under transcriptional control of a melanocyte-specific TRE is an adenovims gene essential for replication. In some embodiments, the adenoviral gene essential for replication is an early gene. In another embodiment, the early gene is El A. In another embodiment, the early gene is EIB. In yet another embodiment, both EIA and EIB are under transcriptional control of a melanocyte- specific TRE. In further embodiments, the adenovims gene essential for replication is EIB, and EIB has a deletion in the 19-kDa region. In some embodiments, the melanocyte-specific TRE is derived from the 5' flanking region of a tyrosinase gene. In other embodiments, the melanocyte-specific TRE is derived from the 5' flanking region of a tyrosinase related protein-1 gene. In other embodiments, the melanocyte-specific TRE is derived from the 5 '-flanking region of a tyrosinase related protein-2 gene. In other embodiments, the melanocyte-specific TRE is derived from the 5' flanking region of a MART-1 gene. In other embodiments, the melanocyte-specific TRE is derived from the 5 ' -flanking region of a gene which is aberrantly expressed in melanomas. In other embodiments, the invention provides an adenovims vector comprising (a) an adenovims gene under transcriptional control of a melanocyte-specific TRE; and (b) an E3 region. In some of these embodiments the E3 region is under transcriptional control of a melanocyte-specific TRE. In another aspect, the invention provides a host cell comprising the melanocyte specific adenovirus vector(s) described herein. In another aspect, the invention provides pharmaceutical compositions comprising a melanocyte specific adenovims vector(s) described herein. In another aspect, the invention provides kits which contain a melanocyte adenoviral vector(s) described herein. In another aspect, methods are provided for conferring selective cytoxicity in target cells (i.e., cells which permit or induce a melanocyte-specific TRE to function), comprising contacting the cells with an adenovims vector(s) described herein, whereby the vector enters the cell. In another aspect, methods are provided for propagating an adenovims specific for melanocytes, said method comprising combining an melanocyte specific adenovims vector(s) described herein with melanocytes, whereby said adenovims is propagated. The invention further provides methods of suppressing melanoma cell growth, comprising contacting a melanoma cell with a melanocyte specific adenoviral vector ofthe invention such that the adenoviral vector enters the melanoma cell and exhibits selective cytotoxicity for the melanoma cell. In another aspect, methods are provided for detecting melanocytes, including melanoma cells, in a biological sample, comprising contacting cells of a biological sample with a melanocyte adenovims vector(s) described herein, and detecting replication ofthe adenovims vector, if any. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic of plasmid construct CP627 as described in Example 1. Figures 2A-2B is a series of schematic depictions of various adenovimses described herein. Figure 3 depicts the replication efficiency of different viruses as described in Example 4. Figures 4A and 4B show viral yield for different liver-specific vectors in different cell types. Figure 5 is a schematic representation of adenovims vectors comprising AFP-TRE with and without IRES. Figure 6 depicts an E3 region. Figure 7 is a schematic representation of adenovims vectors described herein. Figure 8 depicts in vivo antitumor activity of CV890 containing an IRES. This figure depicts the results of a HepG2 Xenograph treated with CV790 or CV890. Figure 9 depicts an ADP nucleotide and amino acid sequence. Figure 10 depicts an IC 50 isobologram of doxombicin and CV 890 on Hep3B cells at day 5. Figure 11 depicts in vivo efficacy of CV890 with doxombicin. Hep3B nude mouse xenografts were grouped (n=6) and treated with CV890 alone (lxlO 11 particles/dose, iv), doxombicin alone (lOmg kg, ip), CV890 and doxorubicin combination (lxlO 11 particles of CV890 through tail vein and lOmg/kg doxombicin ip), or vehicle control. Tumor size was measured weekly and the tumor volume were normalized as 100% at the day of treatment. Error bars represent the standard error of the mean. Figure 12 shows the vims yield of CV802, CV882 and CV884 in cell lines. MODES FOR CARRYING OUT THE INVENTION We have discovered and constructed improved adenovims vectors comprising co- transcribed first and second genes under transcriptional control of a heterologous, target cell-specific transcriptional regulatory element (TRE), wherein the second gene is under translational control of an internal ribosome entry site (IRES). In one embodiment, the first and second genes are co-transcribed as a single mRNA and the second gene has a mutation in or deletion of its endogenous promoter. In another embodiment, at least one ofthe genes is an adenovirus gene and in yet another embodiment, both genes are adenovims genes, including adenovims genes that are essential for viral replication. The adenovims vector may comprise a gene that contributes to cytotoxicity (whether direct and/or indirect), and/or causes cell death. An example of an adenovims gene that contributes to cytotoxicity includes, but is not limited to, the adenovims death protein gene. In some aspects ofthe present invention, an adenovims vector comprising co- transcribed first and second genes under transcriptional control of a target cell-specific TRE, wherein the second gene is under translational control of an IRES, exhibits greater specificity for the target cell than an adenovims vector comprising a target cell-specific TRE operably linked to a gene and lacking an IRES. In some embodiments, specificity is conferred by preferential transcription and/or translation ofthe first and second genes due to the presence of a target cell specific TRE. In other embodiments, specificity is conferred by preferential replication ofthe adenovims vectors in target cells due to the target cell- specific TRE driving transcription of a gene essential for replication. Also disclosed herein are IRES containing adenovims vectors comprising an adenovims gene essential for viral replication wherein said essential gene has a mutation in or deletion of its endogenous promoter. In an embodiment disclosed herein, the adenovims vectors comprise the adenovims early gene EIA which has a deletion of its endogenous promoter. In another embodiment disclosed herein, the adenovims vectors comprise the adenovims early gene EIB which has a deletion of its endogenous promoter. In other embodiments disclosed herein, the 19-kDa region of EIB is deleted. In another aspect, the adenovims vectors disclosed herein comprise an adenovims gene essential for viral replication wherein said essential gene has a mutation in or deletion of its endogenous enhancer. In one embodiment, the adenovims vector comprises the adenovirus early gene EIA which has a mutation of or deletion in its endogenous promoter. In one embodiment, the adenovims vector comprises the adenovims early gene EIA which has a mutation of or deletion in El A enhancer 1. In a further embodiment, the adenovims vector comprises the adenovims early gene EIA which has a mutation of or deletion in its endogenous promoter and a mutation of or deletion in the EIA enhancer. In an additional embodiment, the adenovims vector comprises the adenovims early gene EIA which has a mutation of or deletion in its endogenous promoter and the adenovims early gene EIB which has a mutation of or deletion in its endogenous promoter. In an additional embodiment, the adenovims vector comprises the adenovims early gene EIA, which has a mutation of or deletion in its endogenous promoter and a mutation of or deletion in the EIA enhancer I, and the adenovims early gene EIB which has a mutation of or deletion in its endogenous promoter. In other embodiments disclosed herein, the 19-kDa region of EIB is deleted. The replication-competent adenovims vectors ofthe present invention take advantage of what has been heretofore considered an undesirable aspect of adenovims vectors, namely their replication and possible concomitant immunogenicity. Runaway infection is prevented due to the cell-specific requirements for viral replication. Without wishing to be bound by any particular theory, it is noted that production of adenovims proteins can serve to activate and/or stimulate the immune system, either generally or specifically, toward target cells producing adenoviral proteins. This type of immune stimulation can be an important consideration in the cancer context, where patients are often moderately to severely immunocompromised. The adenovirus vectors ofthe present invention comprising an intergenic IRES element(s) which links the translation of two or more genes, reflects an improvement over vector constructs which use identical control regions to drive expression of two or more desired genes in that any potential for homologous recombination based on the presence of homologous control regions in the vector is removed. As demonstrated herein, adenovims vectors comprising an IRES are stable and in some embodiments provide better specificity than vectors not containing an IRES. Another advantage of an adenovims vector comprising an intergenic IRES is that the use of an IRES rather than a second TRE may provide additional space in the vector for an additional gene(s) such as a therapeutic gene. Thus, the adenovims vectors comprising a second gene under control of an IRES retain a high level of target cell specificity and remain stable in the target cell. Accordingly, in one aspect ofthe invention, the viral vectors disclosed herein comprise at least one IRES within a multicistronic transcript, wherein production ofthe multicistronic transcript is regulated by a heterologous, target cell-specific TRE. For adenovims vectors comprising a second gene under control of an IRES, it is preferred that the endogenous promoter of a gene under translational control of an IRES be deleted so that the endogenous promoter does not interfere with transcription ofthe second gene. It is preferred that the second gene be in frame with the IRES if the IRES contains an initiation codon. If an initiation codon, such as ATG, is present in the IRES, it is preferred that the initiation codon ofthe second gene is removed and that the IRES and the second gene are in frame. Alternatively, if the IRES does not contain an initiation codon or if the initiation codon is removed from the IRES, the initiation codon ofthe second gene is used. In one embodiment, the adenovims vectors comprises the adenovims essential genes, EIA and EIB genes, under the transcriptional control of a heterologous, cell-specific TRE, and an IRES introduced between EIA and EIB. Thus, both EIA and EIB are under common transcriptional control, and translation of EIB coding region is obtained by virtue ofthe presence ofthe IRES. In one embodiment, EIA has its endogenous promoter deleted. In another embodiment, EIA has an endogenous enhancer deleted and in yet an additional embodiment, EIA has its endogenous promoter deleted and EIA enhancer I deleted. In another embodiment, EIB has its endogenous promoter deleted. In other embodiments disclosed herein, the 19-kDa region of EIB is deleted. To provide cytotoxicity to target cells, one or more transgenes having a cytotoxic effect may be present in the vector. Additionally, or alternatively, an adenovims gene that contributes to cytotoxicity and/or cell death, such as the adenovims death protein (ADP) gene, can be included in the vector, optionally under the selective transcriptional control of a heterologous TRE and optionally under the translational control of an IRES. Examples of target cells include neoplastic cells, although any cell for which it is desirable and/or tolerable to sustain a cytotoxic activity can be a target cell. By combining an adenovims vector(s) comprising a target cell-specific TRE with a mixture of target and non-target cells, in vitro or in vivo, the vector(s) preferentially replicates in the target cells, causing cytotoxic and/or cytolytic effects. Once the target cells are destroyed due to selective cytotoxic and/or cytolytic activity, replication ofthe vector(s) is significantly reduced, lessening the probability of runaway infection and undesirable bystander effects. In vitro cultures can be retained to continually monitor the mixture (such as, for example, a biopsy or other appropriate biological sample) for the presence ofthe undesirable target cell, e.g., a cancer cell in which the target cell-specific TRE is functional. The adenovims vectors ofthe present invention can also be used in ex vivo procedures wherein desirable biological samples comprising target cells are removed from the animal, subjected to exposure to an adenovims vector ofthe present invention comprising a target cell-specific TRE and then replaced within the animal. General Techniques The practice ofthe present invention will employ, unless otherwise indicated, conventional techniques of molecular biology (including recombinant techniques), microbiology, cell biology, biochemistry, and immunology, which are within the skill of the art. Such techniques are explained fully in the literature, such as, Molecular Cloning: A Laboratory Manual, second edition (Sambrook et al, 1989); Oligonucleotide Synthesis (M.J. Gait, ed., 1984); Animal Cell Culture (RJ. Freshney, ed., 1987); Methods in Enzymology (Academic Press, Inc.); Handbook of Experimental Immunology (D.M. Wei & C.C. Blackwell, eds.); Gene Transfer Vectors for Mammalian Cells (J.M. Miller & M.P. Calos, eds., 1987); Current Protocols in Molecular Biology (F.M. Ausubel et al, eds., 1987 and annual updates); PCR: The Polymerase Chain Reaction, (Mullis et al, eds., 1994); Current Protocols in Immunology (J.E. Coligan et al, eds., 1991 and annual updates). For techniques related to adenovims, see, inter alia, Feigner and Ringold (1989) Nature 337:387-388; Berkner and Sharp (1983) Nucl. Acids Res. 11 :6003-6020; Graham (1984) EMBO J. 3:2917-2922; Bett et al. (1993) J. Virology 67:5911-5921; Bett et al. (1994) Proc. Natl. Acad. Sci. USA 91:8802-8806. Definitions As used herein, an "internal ribosome entry site" or "IRES" refers to an element that promotes direct internal ribosome entry to the initiation codon, such as ATG, of a cistron (a protein encoding region), thereby leading to the cap-independent translation of the gene. Jackson RJ, Howell MT, Kaminski A (1990) Trends Biochem Sci 15(12):477-83) and Jackson RJ and Kaminski, A. (1995) SNA 1(10):985-1000). The present invention encompasses the use of any IRES element which is able to promote direct internal ribosome entry to the initiation codon of a cistron. "Under translational control of an IRES" as used herein means that translation is associated with the IRES and proceeds in a cap-independent manner. Examples of "IRES" known in the art include, but are not limited to IRES obtainable from picornavirus (Jackson et al., 1990, Trends Biochem Sci 15(12):477-483); and IRES obtainable from viral or cellular mRNA sources, such as for example, immunogloublin heavy-chain binding protein (BiP), the vascular endothelial growth factor (VEGF) (Huez et al. (1998) Mol. Cell. Biol. 18(11):6178-6190), the fibroblast growth factor 2, and insulin-like growth factor, the translational initiation factor eIF4G, yeast transcription factors TFIID and HAP4. IRES have also been reported in different vi ses such as cardioviras, rhinovims, aphthovims, HCV, Friend murine leukemia vims (FrMLV) and Moloney murine leukemia vims (MoMLN). As used herein, "IRES" encompasses functional variations of IRES sequences as long as the variation is able to promote direct internal ribosome entry to the initiation codon of a cistron. In preferred embodiments, the IRES is mammalian. In other embodiments, the IRES is viral or protozoan. In one illustrative embodiment disclosed herein, the IRES is obtainable from encephelomycarditis vims (ECMV) (commercially available from Νovogen, Duke et al. (1992) J. Virol 66(3):1602-1609). In another illustrative embodiment disclosed herein, the IRES is from VEGF. Table I and Table II disclose a variety of IRES sequences useful in the present invention. A "multicistronic transcript" refers to an mRΝA molecule which contains more than one protein coding region, or cistron. A mRΝA comprising two coding regions is denoted a "bicistronic transcript." The "5 '-proximal" coding region or cistron is the coding region whose translation initiation codon (usually AUG) is closest to the 5 '-end of a multicistronic mRNA molecule. A "5 '-distal" coding region or cistron is one whose translation initiation codon (usually AUG) is not the closest initiation codon to the 5' end ofthe mRNA. The terms "5 '-distal" and "downstream" are used synonymously to refer to coding regions that are not adjacent to the 5 ' end of a mRNA molecule. As used herein, "co-transcribed" means that two (or more) coding regions of polynucleotides are under transcriptional control of single transcriptional control element. A "gene" refers to a coding region of a polynucleotide. A "gene" may or may not include non-coding sequences and/or regulatory elements. As used herein, a "transcription response element" or "transcriptional regulatory element", or "TRE" is a polynucleotide sequence, preferably a DNA sequence, which increases transcription of an operably linked polynucleotide sequence in a host cell that allows that TRE to function. A TRE can comprise an enhancer and/or a promoter. A "transcriptional regulatory sequence" is a TRE. A "target cell-specific transcriptional response element" or "target cell-specific TRE" is a polynucleotide sequence, preferably a DNA sequence, which is preferentially functional in a specific type of cell, that is, a target cell. Accordingly, a target cell-specific TRE transcribes an operably linked polynucleotide sequence in a target cell that allows the target cell-specific TRE to function. The term "target cell-specific", as used herein, is intended to include cell type specificity, tissue specificity, developmental stage specificity, and tumor specificity, as well as specificity for a cancerous state of a given target cell. "Target cell-specific TRE" includes cell type- specific and cell status-specific TRE, as well as "composite" TREs. The term "composite TRE" includes a TRE which comprises both a cell type-specific and a cell status-specific TRE. A target cell-specific TRE can also include a heterologous component, including, for example, an SV40 or a cytomegalovirus (CMV) promoter(s). An example of a target cell specific TRE which is tissue specific is a CMV TRE which contains both promoter(s) and enhancer(s). As described in more detail herein, a target cell-specific TRE can comprise any number of configurations, including, but not limited to, a target cell-specific promoter; and target cell-specific enhancer; a heterologous promoter and a target cell-specific enhancer; a target cell-specific promoter and a heterologous enhancer; a heterologous promoter and a heterologous enhancer; and multimers ofthe foregoing. The promoter and enhancer components of a target cell-specific TRE may be in any orientation and/or distance from the coding sequence of interest, as long as the desired target cell-specific transcriptional activity is obtained. Transcriptional activation can be measured in a number of ways known in the art (and described in more detail below), but is generally measured by detection and/or quantitation of mRNA or the protein product ofthe coding sequence under control of (i.e., operably linked to) the target cell-specific TRE. As discussed herein, a target cell-specific TRE can be of varying lengths, and of varying sequence composition. As used herein, the term "cell status-specific TRE" is preferentially functional, i.e., confers transcriptional activation on an operably linked polynucleotide in a cell which allows a cell status-specific TRE to function, i.e., a cell which exhibits a particular physiological condition, including, but not limited to, an aberrant physiological state. "Cell status" thus refers to a given, or particular, physiological state (or condition) of a cell, which is reversible and/or progressive. The physiological state may be generated internally or externally; for example, it may be a metabolic state (such as in response to conditions of low oxygen), or it may be generated due to heat or ionizing radiation. "Cell status" is distinct from a "cell type", which relates to a differentiation state of a cell, which under normal conditions is irreversible. Generally (but not necessarily), as discussed herein, a cell status is embodied in an aberrant physiological state, examples of which are given below. A "functional portion" of a target cell-specific TRE is one which confers target cell- specific transcription on an operably linked gene or coding region, such that the operably linked gene or coding region is preferentially expressed in the target cells. By "transcriptional activation" or an "increase in transcription," it is intended that transcription is increased above basal levels in the target cell (i.e., target cell) by at least about 2 fold, preferably at least about 5 fold, preferably at least about 10 fold, more preferably at least about 20 fold, more preferably at least about 50 fold, more preferably at least about 100 fold, more preferably at least about 200 fold, even more preferably at least about 400 fold to about 500 fold, even more preferably at least about 1000 fold. Basal levels are generally the level of activity (if any) in a non-target cell (i.e., a different cell type), or the level of activity (if any) of a reporter construct lacking a target cell-specific TRE as tested in a target cell line. A "functionally-preserved variant" of a target cell-specific TRE is a target cell- specific TRE which differs from another target cell-specific TRE, but still retains target cell-specific transcription activity, although the degree of activation may be altered (as discussed below). The difference in a target cell-specific TRE can be due to differences in linear sequence, arising from, for example, single base mutation(s), addition(s), deletion(s), and/or modification(s) ofthe bases. The difference can also arise from changes in the sugar(s), and/or linkage(s) between the bases of a target cell-specific TRE. For example, certain point mutations within sequences of TREs have been shown to decrease transcription factor binding and stimulation of transcription. See Blackwood, et al. (1998) Science 281:60-63 and Smith et al. (1997) J Biol. Chem. 272:27493-27496. One of skill in the art would recognize that some alterations of bases in and around transcription factor binding sites are more likely to negatively affect stimulation of transcription and cell- specificity, while alterations in bases which are not involved in transcription factor binding are not as likely to have such effects. Certain mutations are also capable of increasing TRE activity. Testing ofthe effects of altering bases may be performed in vitro or in vivo by any method known in the art, such as mobility shift assays, or transfecting vectors containing these alterations in TRE functional and TRE non-functional cells. Additionally, one of skill in the art would recognize that point mutations and deletions can be made to a TRE sequence without altering the ability ofthe sequence to regulate transcription. As used herein, a TRE derived from a specific gene is referred to by the gene from which it was derived and is a polynucleotide sequence which regulates transcription of an operably linked polynucleotide sequence in a host cell that expresses said gene. For example, as used herein, a "human glandular kallikrein transcriptional regulatory element", or " L2 -TRE" is a polynucleotide sequence, preferably a DNA sequence, which increases transcription of an operably linked polynucleotide sequence in a host cell that allows an hKLK2-TRE to function, such as a cell (preferably a mammalian cell, even more preferably a human cell) that expresses androgen receptor, such as a prostate cell. An hKLK2-TKE is thus responsive to the binding of androgen receptor and comprises at least a portion of an hKLK2 promoter and/or an hKLK2 enhancer (i.e., the ARE or androgen receptor binding site). As used herein, a "probasin {PB) transcriptional regulatory element", or "E5-TRE" is a polynucleotide sequence, preferably a DNA sequence, which selectively increases transcription of an operably-linked polynucleotide sequence in a host cell that allows a PB- TRE to function, such as a cell (preferably a mammalian cell, more preferably a human cell, even more preferably a prostate cell) that expresses androgen receptor. A E5-TRE is thus responsive to the binding of androgen receptor and comprises at least a portion of a PB promoter and/or a PB enhancer (i.e., the ARE or androgen receptor binding site). As used herein, a "prostate-specific antigen {PSA) transcriptional regulatory element", or "E&4-TRE", or "ESE-TRE" is a polynucleotide sequence, preferably a DNA sequence, which selectively increases transcription of an operably linked polynucleotide sequence in a host cell that allows a E&4-TRE to function, such as a cell (preferably a mammalian cell, more preferably a human cell, even more preferably a prostate cell) that expresses androgen receptor. A E&4-TRE is thus responsive to the binding of androgen receptor and comprises at least a portion of a PSA promoter and/or a PSA enhancer (i.e., the ARE or androgen receptor binding site). As used herein, a "carcinoembryonic antigen {CEA) transcriptional regulatory element", or "CE 4-TRE" is a polynucleotide sequence, preferably a DNA sequence, which selectively increases transcription of an operably linked polynucleotide sequence in a host cell that allows a CEA -TRE to function, such as a cell (preferably a mammalian cell, even more preferably a human cell) that expresses CEA. The CEA -TRE is responsive to transcription factors and/or co-factor(s) associated with CEA-producing cells and comprises at least a portion ofthe CEA promoter and/or enhancer. As used herein, an "α-fetoprotein {AFP) transcriptional regulatory element", or "AFP-TKE" is a polynucleotide sequence, preferably a DNA sequence, which selectively increases transcription (of an operably linked polynucleotide sequence) in a host cell that allows an AFP-TKE to function, such as a cell (preferably a mammalian cell, even more preferably a human cell) that expresses AFP. The .4EE-TRE is responsive to transcription factors and or co-factor(s) associated with AFP-producing cells and comprises at least a portion ofthe AFP promoter and/or enhancer. As used herein, an "a mucin gene {MUG) transcriptional regulatory element", or " JCi -TRE" is a polynucleotide sequence, preferably a DNA sequence, which selectively increases transcription (of an operably-linked polynucleotide sequence) in a host cell that allows a MLUCl -TRE to function, such as a cell (preferably a mammalian cell, even more preferably a human cell) that expresses MUC1. The MUCl -TRE is responsive to transcription factors and/or co-factor(s) associated with MUCl -producing cells and comprises at least a portion ofthe MUCl promoter and/or enhancer. As used herein, a "urothelial cell-specific transcriptional response element", or "urothelial cell-specific TRE" is polynucleotide sequence, preferably a DNA sequence, which increases transcription of an operably linked polynucleotide sequence in a host cell that allows a urothelial-specific TRE to function, i.e., a target cell. A variety of urothelial cell-specific TREs are known, are responsive to cellular proteins (franscription factors and/or co-factor(s)) associated with urothelial cells, and comprise at least a portion of a urothelial-specific promoter and/or a urothelial-specific enhancer. Methods are described herein for measuring the activity of a urothelial cell-specific TRE and thus for determining whether a given cell allows a urothelial cell-specific TRE to function. As used herein, a "melanocyte cell-specific transcriptional response element", or "melanocyte cell-specific TRE" is polynucleotide sequence, preferably a DNA sequence, which increases franscription of an operably linked polynucleotide sequence in a host cell that allows a melanocyte-specific TRE to function, i.e., a target cell. A variety of melanocyte cell-specific TREs are known, are responsive to cellular proteins (franscription factors and/or co-factor(s)) associated with melanocyte cells, and comprise at least a portion of a melanocyte-specific promoter and/or a melanocyte-specific enhancer. Methods are described herein for measuring the activity of a melanocyte cell-specific TRE and thus for determining whether a given cell allows a melanocyte cell-specific TRE to function. An "EIB 19-kDa region" (used interchangeably with "EIB 19-kDa genomic region") refers to the genomic region ofthe adenovims EIB gene encoding the EIB 19- kDa product. According to wild-type Ad5 , the EIB 19-kDa region is a 261bp region located between nucleotide 1714 and nucleotide 2244. The EIB 19-kDa region has been described in, for example, Rao et al, Proc. Natl. Acad. Sci. USA, 89:1142-1146. The present invention encompasses deletion of part or all of the EIB 19-kDa region as well as embodiments wherein the EIB 19-kDa region is mutated, as long as the deletion or mutation lessens or eliminates the inhibition of apoptosis associated with ElB-19kDa. As used herein, a target cell-specific TRE can comprise any number of configurations, including, but not limited to, a target cell-specific promoter; a target cell- specific enhancer; a target cell-specific promoter and a target cell-specific enhancer; a target cell-specific promoter and a heterologous enhancer; a heterologous promoter and a target cell-specific enhancer; and multimers ofthe foregoing. The promoter and enhancer components of a target cell-specific TRE may be in any orientation and/or distance from the coding sequence of interest, as long as the desired target cell-specific transcriptional activity is obtained. Transcriptional activation can be measured in a number of ways known in the art (and described in more detail below), but is generally measured by detection and/or quantitation of mRNA or the protein product ofthe coding sequence under confrol of (i.e., operably linked to) the target cell-specific TRE. "Replicating preferentially", as used herein, means that the adenovims replicates more in a target cell than a non-target cell. Preferably, the adenovims replicates at a significantly higher rate in target cells than non target cells; preferably, at least about 2-fold higher, preferably, at least about 5-fold higher, more preferably, at least about 10-fold higher, still more preferably at least about 50-fold higher, even more preferably at least about 100-fold higher, still more preferably at least about 400- to 500-fold higher, still more preferably at least about 1000-fold higher, most preferably at least about 1 x 10 6 higher. Most preferably, the adenovims replicates solely in the target cells (that is, does not replicate or replicates at a very low levels in non-target cells). As used herein, the term "vector" refers to a polynucleotide construct designed for transduction/transfection of one or more cell types. Vectors may be, for example, "cloning vectors" which are designed for isolation, propagation and replication of inserted nucleotides, "expression vectors" which are designed for expression of a nucleotide sequence in a host cell, or a "viral vector" which is designed to result in the production of a recombinant virus or vims-like particle, or "shuttle vectors", which comprise the attributes of more than one type of vector. An "adenovirus vector" or "adenoviral vector" (used interchangeably) comprises a polynucleotide construct ofthe invention. A polynucleotide construct of this invention may be in any of several forms, including, but not limited to, DNA, DNA encapsulated in an adenovims coat, DNA packaged in another viral or viral-like form (such as herpes simplex, and AAV), DNA encapsulated in liposomes, DNA complexed with polylysine, complexed with synthetic polycationic molecules, conjugated with fransferrin, and complexed with compounds such as PEG to immunologically "mask" the molecule and/or increase half-life, and conjugated to a nonviral protein. Preferably, the polynucleotide is DNA. As used herein, "DNA" includes not only bases A, T, C, and G, but also includes any of their analogs or modified forms of these bases, such as methylated nucleotides, intemucleotide modifications such as uncharged linkages and thioates, use of sugar analogs, and modified and/or alternative backbone structures, such as polyamides. For purposes of this invention, adenovims vectors are replication-competent in a target cell. The terms "polynucleotide" and "nucleic acid", used interchangeably herein, refer to a polymeric form of nucleotides of any length, either ribonucleotides or deoxyribonucleotides. These terms include a single-, double- or triple-stranded DNA, genomic DNA, cDNA, RNA, DNA-RNA hybrid, or a polymer comprising purine and pyrimidine bases, or other natural, chemically, biochemically modified, non-natural or derivatized nucleotide bases. The backbone ofthe polynucleotide can comprise sugars and phosphate groups (as may typically be found in RNA or DNA), or modified or substituted sugar or phosphate groups. Alternatively, the backbone ofthe polynucleotide can comprise a polymer of synthetic subunits such as phosphoramidates and thus can be a oligodeoxynucleoside phosphoramidate (P-NH2) or a mixed phosphoramidate- phosphodiester oligomer. Peyrottes et al. {1996) Nucleic Acids Res. 24: 1841-8; Chaturvedi et al. (1996) Nucleic Acids Ses. 24: 2318-23; Schultz et al. (1996) Nucleic Acids Ses. 24: 2966-73. A phosphorothioate linkage can be used in place of a phosphodiester linkage. Braun et al. (1988) J. Immunol. 141: 2084-9; Latimer et al. (1995) Molec. Immunol. 32: 1057-1064. In addition, a double-sfranded polynucleotide can be obtained from the single stranded polynucleotide product of chemical synthesis either by synthesizing the complementary sfrand and annealing the strands under appropriate conditions, or by synthesizing the complementary sfrand de novo using a DNA polymerase with an appropriate primer. Reference to a polynucleotide sequence (such as referring to a SEQ ID NO) also includes the complement sequence. The following are non-limiting examples of polynucleotides: a gene or gene fragment, exons, introns, mRNA, tRNA, rRNA, ribozymes, cDNA, recombinant polynucleotides, branched polynucleotides, plasmids, vectors, isolated DNA of any sequence, isolated RNA of any sequence, nucleic acid probes, and primers. A polynucleotide may comprise modified nucleotides, such as methylated nucleotides and nucleotide analogs, uracyl, other sugars and linking groups such as fluororibose and thioate, and nucleotide branches. The sequence of nucleotides may be interrupted by non- nucleotide components. A polynucleotide may be further modified after polymerization, such as by conjugation with a labeling component. Other types of modifications included in this definition are caps, substitution of one or more ofthe naturally occurring nucleotides with an analog, and introduction of means for attaching the polynucleotide to proteins, metal ions, labeling components, other polynucleotides, or a solid support. Preferably, the polynucleotide is DNA. As used herein, "DNA" includes not only bases A, T, C, and G, but also includes any of their analogs or modified forms of these bases, such as methylated nucleotides, intemucleotide modifications such as uncharged linkages and thioates, use of sugar analogs, and modified and/or alternative backbone structures, such as polyamides. A polynucleotide or polynucleotide region has a certain percentage (for example, 80%, 85%, 90%, or 95%) of "sequence identity" to another sequence means that, when aligned, that percentage of bases are the same in comparing the two sequences. This alignment and the percent homology or sequence identity can be determined using software programs known in the art, for example those described in Current Protocols in Molecular Biology (F.M. Ausubel et al., eds., 1987) Supplement 30, section 7.7.18. A preferred alignment program is ALIGN Plus (Scientific and Educational Software, Pennsylvania), preferably using default parameters, which are as follows: mismatch = 2; open gap = 0; extend gap = 2. "Under transcriptional confrol" is a term well understood in the art and indicates that transcription of a polynucleotide sequence, usually a DNA sequence, depends on its being operably (operatively) linked to an element which confributes to the initiation of, or promotes, franscription. "Operably linked" refers to a juxtaposition wherein the elements are in an arrangement allowing them to function. An "E3 region" (used interchangeably with "E3") is a term well understood in the art and means the region ofthe adenoviral genome that encodes the E3 products (discussed herein). Generally, the E3 region is located between about 28583 and 30470 ofthe adenoviral genome. The E3 region has been described in various publications, including, for example, Wold et al. (1995) Curr. Topics Microbiol Immunol. 199:237-274. A "portion" ofthe E3 region means less than the entire E3 region, and as such includes polynucleotide deletions as well as polynucleotides encoding one or more polypeptide products ofthe E3 region. As used herein, "cytotoxicity" is a term well understood in the art and refers to a state in which a cell's usual biochemical or biological activities are compromised (i.e., inhibited). These activities include, but are not limited to, metabolism; cellular replication; DNA replication; franscription; franslation; uptake of molecules. "Cytotoxicity" includes cell death and/or cytolysis. Assays are known in the art which indicate cytotoxicity, such as dye exclusion, 3 H-thymidine uptake, and plaque assays. The term "selective cytotoxicity", as used herein, refers to the cytotoxicity conferred by an adenovims vector ofthe present invention on a cell which allows or induces a target cell-specific TRE to function (a target cell) when compared to the cytotoxicity conferred by an adenoviral vector ofthe present invention on a cell which does not allow a target cell-specific TRE to function (a non-target cell). Such cytotoxicity may be measured, for example, by plaque assays, by reduction or stabilization in size of a tumor comprising target cells, or the reduction or stabilization of serum levels of a marker characteristic ofthe tumor cells, or a tissue-specific marker, e.g., a cancer marker. In the context of adenovims, a "heterologous polynucleotide" or "heterologous gene" or "transgene" is any polynucleotide or gene that is not present in wild-type adenovims. Preferably, the transgene will also not be expressed or present in the target cell prior to introduction by the adenovims vector. Examples of preferred transgenes are provided below. In the context of adenovims, a "heterologous" promoter or enhancer is one which is not associated with or derived from an adenovims gene. In the context of adenovims, an "endogenous" promoter, enhancer, or TRE is native to or derived from adenovirus. In the context of promoter, an "inactivation" means that there is a mutation of or deletion in part or all ofthe ofthe endogenous promoter, ie, a modification or alteration ofthe endogenous promoter, such as, for example, a point mutation or insertion, which disables the function ofthe promoter. In the context of a target cell-specific TRE, a "heterologous" promoter or enhancer is one which is derived from a gene other than the gene from which a reference target cell- specific TRE is derived. "Suppressing" tumor growth indicates a growth state that is curtailed when compared to growth without contact with, i.e., transfection by, an adenoviral vector described herein. Tumor cell growth can be assessed by any means known in the art, including, but not limited to, measuring tumor size, determining whether tumor cells are proliferating using a H-thymidine incorporation assay, or counting tumor cells. "Suppressing" tumor cell growth means any or all ofthe following states: slowing, delaying, and stopping tumor growth, as well as tumor shrinkage. As used herein, the terms "neoplastic cells", "neoplasia", "tumor", "tumor cells", "cancer" and "cancer cells", (used interchangeably) refer to cells which exhibit relatively autonomous growth, so that they exhibit an aberrant growth phenotype characterized by a significant loss of confrol of cell proliferation (i.e., de-regulated cell division). Neoplastic cells can be malignant or benign. A "host cell" includes an individual cell or cell culture which can be or has been a recipient of an adenoviral vector(s) of this invention. Host cells include progeny of a single host cell, and the progeny may not necessarily be completely identical (in morphology or in total DNA complement) to the original parent cell due to natural, accidental, or deliberate mutation and/or change. A host cell includes cells fransfected or infected in vivo or in vitro with an adenoviral vector of this invention. "Replication" and "propagation" are used interchangeably and refer to the ability of an adenovims vector ofthe invention to reproduce or proliferate. These terms are well understood in the art. For purposes of this invention, replication involves production of adenovims proteins and is generally directed to reproduction of adenovims. Replication can be measured using assays standard in the art and described herein, such as a burst assay or plaque assay. "Replication" and "propagation" include any activity directly or indirectly involved in the process of vims manufacture, including, but not limited to, viral gene expression; production of viral proteins, nucleic acids or other components; packaging of viral components into complete vi ses; and cell lysis. An "ADP coding sequence" is a polynucleotide that encodes ADP or a functional fragment thereof. In the context of ADP, a "functional fragment" of ADP is one that exhibits cytotoxic activity, especially cell lysis, with respect to adenoviral replication. Ways to measure cytotoxic activity are known in the art and are described herein. A polynucleotide that "encodes" an ADP polypeptide is one that can be transcribed and/or translated to produce an ADP polypeptide or a fragment thereof. The anti-sense sfrand of such a polynucleotide is also said to encode the sequence. An "ADP polypeptide" is a polypeptide containing at least a portion, or region, of the amino acid sequence of an ADP and which displays a function associated with ADP, particularly cytotoxicity, more particularly, cell lysis. As discussed herein, these functions can be measured using techniques known in the art. It is understood that certain sequence variations may be used, due to, for example, conservative amino acid substitutions, which may provide ADP polypeptides. "Androgen receptor," or AR, as used herein refers to a protein whose function is to specifically bind to androgen and, as a consequence ofthe specific binding, recognize and bind to an androgen response element (ARE), following which the AR is capable of regulating transcriptional activity. The AR is a nuclear receptor that, when activated, binds to cellular androgen-responsive element(s). In normal cells the AR is activated by androgen, but in non-normal cells (including malignant cells) the AR may be activated by non-androgenic agents, including hormones other than androgens. Encompassed in the term "androgen receptor" are mutant forms of an androgen receptor, such as those characterized by amino acid additions, insertions, truncations and deletions, as long as the function is sufficiently preserved. Mutants include androgen receptors with amino acid additions, insertions, truncations and deletions, as long as the function is sufficiently preserved. In this context, a functional androgen receptor is one that binds both androgen and, upon androgen binding, an ARE. A polynucleotide sequence that is "depicted in" a SEQ ID NO means that the sequence is present as an identical contiguous sequence in the SEQ ID NO. The term encompasses portions, or regions ofthe SEQ ID NO as well as the entire sequence contained within the SEQ ID NO. A "biological sample" encompasses a variety of sample types obtained from an individual and can be used in a diagnostic or monitoring assay. The definition encompasses blood and other liquid samples of biological origin, solid tissue samples such as a biopsy specimen or tissue cultures or cells derived therefrom, and the progeny thereof. The definition also includes samples that have been manipulated in any way after their procurement, such as by treatment with reagents, solubilization, or enrichment for certain components, such as proteins or polynucleotides. The term "biological sample" encompasses a clinical sample, and also includes cells in culture, cell supernatants, cell lysates, serum, plasma, biological fluid, and tissue samples. An "individual" is a vertebrate, preferably a mammal, more preferably a human. Mammals include, but are not limited to, farm animals, sport animals, rodents, primates, and pets. An "effective amount" is an amount sufficient to effect beneficial or desired results, including clinical results. An effective amount can be administered in one or more administrations. For purposes of this invention, an effective amount of an adenoviral vector is an amount that is sufficient to palliate, ameliorate, stabilize, reverse, slow or delay the progression ofthe disease state. A given TRE is "derived from" a given gene if it is associated with that gene in nature. "Expression" includes franscription and/or franslation. As used herein, the term "comprising" and its cognates are used in their inclusive sense; that is, equivalent to the term "including" and its corresponding cognates. "A," "an" and "the" include plural references unless the context clearly dictates otherwise. Internal Ribosome Entry Site (IRES) IRES elements were first discovered in picomavims mRNAs (Jackson RJ, Howell MT, Kaminski A (1990) Trends Biochem Sci 15(12):477-83) and Jackson RJ and Kaminski, A. (1995) SNA 1(10):985-1000). The present invention provides improved adenovims vectors comprising co-transcribed first and second genes under transcriptional control of a heterologous, target cell-specific TRE, and wherein the second gene (i.e., coding region) is under translational control of an internal ribosome entry site (IRES). Any IRES may be used in the adenovims vectors ofthe invention, as long as they exhibit requisite function in the vectors. Example of IRES which can be used in the present invention include those provided in Table I and referenced in Table II. Examples of IRES elements include the encephelomycarditis vims (EMCV) which is commercially available from Novagen (Duke et al. (1992) J. Virol 66(3): 1602-9) the sequence for which is depicted in Table 1 (SEQ ID NO:l). Another example of an IRES element disclosed herein is the VEGF IRES (Huez et al. (1998) Mol Cell Biol 18(l l):6178-90). This IRES has a short segment and the sequence is depicted in Table 1 (SEQ ID NO:2). The IRES promotes direct internal ribosome entry to the initiation codon of a downstream cistron, leading to cap-independent franslation. Thus, the product of a downstream cistron can be expressed from a bicisfronic (or multicistronic) mRNA, without requiring either cleavage of a polyprotein or generation of a monocisfronic mRNA. Therefore, in one illustrative embodiment ofthe present invention, an adenovims vector comprising EIB under franslational confrol of an IRES allows franslation of EIB from a bicisfronic E1A-E1B mRNA under control of a target cell-specific TRE. Figure 7 provides a schematic representation of adenovims constructs ofthe present invention. Internal ribosome entry sites are approximately 450 nucleotides in length and are characterized by moderate conservation of primary sequence and strong conservation of secondary structure. The most significant primary sequence feature ofthe IRES is a pyrimidine-rich site whose start is located approximately 25 nucleotides upstream of the 3' end ofthe IRES. See Jackson et al (1990). Three major classes of picornaviras IRES have been identified and characterized: (1) the cardio- and aphthovims class (for example, the encephelomycarditis vims, Jang et al. (1990) Gene Dev 4:1560-1572); (2) the entero- and rhinovims class (for example, poliovirases, Borman et al. (1994) EMBOJ. 13:314903157); and (3)the hepatitis A vims (HAV) class, Glass et al. (1993) Virol 193:842-852). For the first two classes, two general principles apply. First, most ofthe 450-nucleotide sequence ofthe IRES functions to maintain particular secondary and tertiary stractures conducive to ribosome binding and translational initiation. Second, the ribosome entry site is an AUG triplet located at the 3' end ofthe IRES, approximately 25 nucleotides downstream of a conserved oligopyrimidine fract. Translation initiation can occur either at the ribosome entry site (cardiovimses) or at the next downstream AUG (entero/rhinovims class). Initiation occurs at both sites in aphthovimses. HCV and pestivimses such as bovine viral diarrhea vims (BVDV) or classical swine fever vims (CSFV) have 341 nt and 370 nt long 5'-UTR respectively. These 5'-UTR fragments form similar RNA secondary stractures and can have moderately efficient IRES function (Tsukiyama-Kohara et al. (1992) J. Virol. 66:1476-1483; Frolov I et al., (1998) SNA 4:1418-1435). Table I depicts the 5'-UTR region from HCV genome sequence (GenBank accession D 14853). Leishmania RNA vims 1 (LRV1) is a double-sfranded RNA vims. Its 128 nt long 5'-UTR has IRES activity to facilitate the cap-independent franslation, (Maga et al. (1995) Mol Cell Biol 15:4884-4889). This fragment also forms conserved stemloop secondary structure and at least the front part is essential. Recent studies showed that both Friend-murine leukemia virus (MLV) 5'-UTR and rat retrofransposon virus-like 30S (VL30) sequences contain IRES structure of retroviral origin (Torrent et al. (1996) Hum Gene Ther 7:603-612). These fragments are also functional as packing signal when used in refrovims derived vectors. Studies of avian reticuloendotheliosis vims type A (REV- A) show that its IRES maps downstream ofthe packaging/dimerization (E/DLS) sequence and the minimal IRES sequence appears to be within a 129 nt fragment (452-580) ofthe 5' leader, immediately upsfream ofthe gag AUG codon (Lopez-Lasfra et al. (1997) Hum Gene Ther 8:1855-1865). In eukaryotic cells, franslation is normally initiated by the ribosome scanning from the capped mRNA 5' end, under the confrol of initiation factors. However, several cellular mRNAs have been found to have IRES structure to mediate the cap-independent franslation (van der Velde, et al. (1999) Int J Biochem Cell Biol. 31:87-106). Examples are immunoglobulin heavy-chain binding protein (BiP) (Macejak et al. (1991) Nature 353:90-94), antennapedia mRNA of Drosophilan (Oh et al. (1992) Gene and Dev 6:1643-1653), fibroblast growth factor-2 (FGF-2) (Vagner et al. (1995) Mol Cell Biol 15:35-44), platelet-derived growth factor B (PDGF-B) (Bernstein et al. (1997) JBiol Chem 272:9356-9362), insulin-like growth factor II (Teerink et al. (1995) Biochim Biophys Acta 1264:403-408), and the franslation initiation factor eIF4G (Gan et al. (1996) JBiol Chem 271:623-626). Table 1 depicts the 5'-noncoding region for BiP and PDGF. Recently, vascular endothelial growth factor (VEGF) was also found to have IRES element (Stein et al. (1998) Mol Cell Biol 18:3112-3119; Huez et al. (1998) Mol Cell Biol 18:6178-6190). Apart from the oligopyrimidine fract, nucleotide sequence er se does not appear to be important for IRES function. Without wishing to be bound by theory, a possible explanation for the function of an IRES is that it forms secondary and/or tertiary stractures which orient particular single-stranded regions of its sequence in a three-dimensional configuration that is conducive to interaction with a mammalian ribosome (either ribosomal protein and/or ribosomal RNA components) and/or initiation factor(s) and/or RNA binding proteins which interact with ribosomes and/or initiation factors. It is also possible that the three-dimensional structure ofthe IRES is determined or stabilized by one or more RNA- binding proteins. Thus it is possible to devise synthetic IRES sequences having similar single-stranded regions in a similar three-dimensional configuration. In certain cases, one or more trans-acting cellular proteins may be required for IRES function. For example, the HAV and entero/rhinoviras IRESes function inefficiently in vitro in reticulocyte lysates. Supplementation of a reticulocyte lysate with a cytoplasmic extract from HeLa, Krebs II ascites, or L-cells restores activity of entero/rhinoviras IRESes. See, for example, Brown et αl. (1979) Virology 91 -.396-405; and Domer et αl. (1984) J. Virol. 50:507-514. Activity ofthe HAV IRES in vitro is stimulated by liver cytoplasmic exfracts. Glass et αl. (1993) Virology 193:1047-1050. These observations indicate that cell-specific franslational regulation can be achieved through the use of a cell- specific IRES. Furthermore, coordinated cell-specific franscriptional and translational regulatory elements can be included in a vector to further increase cell specificity of viral replication. For example, the combination of an AFP-TRE and a HAN-IRES can be used to direct preferential replication of a vector in hepatic cells. Thus, in one illustrative embodiment, a vector comprises an AFP-TRE regulating the franscription of a bicisfronic El A-E1B mRNA in which EIB translation is regulated by an ECMV IRES. In another illustrative embodiment, the vector comprises a probasin-TRE regulating the franscription of a bicisfronic El A-E1B mRNA in which EIB translation is regulated by an ECMV IRES. In yet another illustrative embodiment, a vector comprises a CMV-TRE regulating the franscription of a bicisfronic E1A-E1B mRNA in which EIB franslation is regulated by an ECMV IRES. Examples of IRES which can be used in the present invention include those provided in Table 1 and Table 2. An IRES sequence which may be used in the present invention may be tested as follows. A test vector is produced having a reporter gene, such as luciferase, for example, placed under franslational confrol of an IRES to be tested. A desired cell type is fransfected with the vector containing the desired IRES-reporter gene and an assay is performed to detect the presence ofthe reporter gene. In one illustrative example, the test vector comprises a co-transcribed chloramphemcol fransferase (CAT) and luciferase encoding gene franscriptionally driven by a CMV promoter wherein the luciferase encoding gene is translationally driven by an IRES to be tested. Host cells are transiently transfected with the test vector by means known to those of skill in the art and assayed for the presence of luciferase. IRES may be prepared using standard recombinant and synthetic methods known in the art, and as described in the Examples. For cloning convenience, restriction sites may be engineered into the ends ofthe IRES fragments to be used. Transcriptional response elements (TSEs) The adenovims vectors ofthe invention comprise target cell specific TREs which direct preferential expression of an operatively linked gene (or genes) in a particular target cell. A TRE can be tissue-specific, tumor-specific, developmental stage-specific, cell status specific, etc., depending on the type of cell present in the tissue or tumor. Cell- and tissue-specific franscriptional regulatory elements, as well as methods for their identification, isolation, characterization, genetic manipulation and use for regulation of operatively linked coding sequences, are well known in the art. A TRE can be derived from the franscriptional regulatory sequences of a single gene, or sequences from different genes can be combined to produce a functional TRE. A cell-specific TRE is preferentially functional in a limited population (or type) of cells, e.g., prostate cells or liver cells. Accordingly, in some embodiments, the TRE used is preferentially functional in any ofthe following cell types: prostate; liver; breast; urothelial cells (bladder); colon; lung; ovarian; pancreas; stomach; and uterine. In other embodiments, in accordance with cell status, the TRE is functional in or during: low oxygen conditions (hypoxia); certain stages of cell cycle, such as S phase; elevated temperature; ionizing radiation. As is known in the art, activity of TREs can be inducible. Inducible TREs generally exhibit low activity in the absence of inducer, and are up-regulated in the presence of inducer. Inducers include, for example, nucleic acids, polypeptides, small molecules, organic compounds and/or environmental conditions such as temperature, pressure or hypoxia. Inducible TREs may be preferred when expression is desired only at certain times or at certain locations, or when it is desirable to tifrate the level of expression using an inducing agent. For example, franscriptional activity from the ESE-TRE, E.5-TRE and hKLK2-TSE is inducible by androgen, as described herein and in PCT/US98/04080. Accordingly, in one embodiment ofthe present invention, an adenovims vector comprises an inducible heterologous TRE. TRE multimers are also useful in the disclosed vectors. For example, a TRE can comprise a tandem series of at least two, at least three, at least four, or at least five promoter fragments. Alternatively, a TRE can comprise one or more promoter regions along with one or more enhancer regions. TRE multimers can also comprise promoter and/or enhancer sequences from different genes. The promoter and enhancer components of a TRE can be in any orientation with respect to each other and can be in any orientation and/or any distance from the coding sequence of interest, as long as the desired cell- specific transcriptional activity is obtained. The disclosed vectors are designed such that replication is preferentially enhanced in target cells in which the TRE(s) is (are) functional. More than one TRE can be present in a vector, as long as the TREs are functional in the same target cell. However, it is important to note that a given TRE can be functional in more than one type of target cell. For example, the CEA-TRE functions in, among other cell types, gastric cancer cells, colorectal cancer cells, pancreatic cancer cells and lung cancer cells. A TRE for use in the present vectors may or may not comprise a silencer. The presence of a silencer {i. e. , a negative regulatory element known in the art) can assist in shutting off franscription (and thus replication) in non-target cells. Thus, presence of a silencer can confer enhanced cell-specific vector replication by more effectively preventing replication in non-target cells. Alternatively, lack of a silencer may stimulate replication in target cells, thus conferring enhanced target cell-specificity. As is readily appreciated by one skilled in the art, a TRE is a polynucleotide sequence, and, as such, can exhibit function over a variety of sequence permutations. Methods of nucleotide substitution, addition, and deletion are known in the art, and readily- available functional assays (such as the CAT or luciferase reporter gene assay) allow one of ordinary skill to determine whether a sequence variant exhibits requisite cell-specific franscription regulatory function. Hence, functionally preserved variants of TREs, comprising nucleic acid substitutions, additions, and/or deletions, can be used in the vectors disclosed herein. Accordingly, variant TREs retain function in the target cell but need not exhibit maximal function. In fact, maximal transcriptional activation activity of a TRE may not always be necessary to achieve a desired result, and the level of induction afforded by a fragment of a TRE may be sufficient for certain applications. For example, if used for treatment or palliation of a disease state, less-than-maximal responsiveness may be sufficient if, for example, the target cells are not especially virulent and/or the extent of disease is relatively confined. Certain base modifications may result in enhanced expression levels and/or cell- specificity. For example, nucleic acid sequence deletions or additions within a TRE can move franscription regulatory protein binding sites closer or farther away from each other than they exist in their normal configuration, or rotate them so they are on opposite sides of the DNA helix, thereby altering spatial relationship among TRE-bound transcription factors, resulting in a decrease or increase in transcription, as is known in the art. Thus, while not wishing to be bound by theory, the present disclosure contemplates the possibility that certain modifications of a TRE will result in modulated expression levels as directed by the TRE, including enhanced cell-specificity. Achievement of enhanced expression levels may be especially desirable in the case of more aggressive forms of neoplastic growth, and/or when a more rapid and/or aggressive pattern of cell killing is warranted (for example, in an immunocompromised individual). Transcriptional activity directed by a TRE (including both inhibition and enhancement) can be measured in a number of ways known in the art (and described in more detail below), but is generally measured by detection and/or quantitation of mRNA and/or of a protein product encoded by the sequence under confrol of {i. e. , operably linked to) a TRE. As discussed herein, a TRE can be of varying lengths, and of varying sequence composition. The size of a heterologous TRE will be determined in part by the capacity of the viral vector, which in turn depends upon the contemplated form ofthe vector (see infra). Generally minimal sizes are preferred for TREs, as this provides potential room for insertion of other sequences which may be desirable, such as transgenes (discussed infra) and/or additional regulatory sequences. In a preferred embodiment, such an additional regulatory sequence is an IRES. However, if no additional sequences are contemplated, or if, for example, an adenoviral vector will be maintained and delivered free of any viral packaging constraints, larger TRE sequences can be used as long as the resultant adenoviral vector remains replication-competent. An adenoviral vector can be packaged with extra sequences totaling up to about 5% ofthe genome size, or approximately 1.8 kb, without requiring deletion of viral sequences. If non-essential sequences are removed from the adenovirus genome, an additional 4.6 kb of insert can be tolerated (t ' .e., for a total insertion capacity of about 6.4 kb). Examples of non-essential adenoviral sequences that can be deleted are E3, and E4 sequences other than those which encode E4 ORF6. To minimize non-specific replication, endogenous (e. g, adenovirus) TREs are preferably removed from the vector. Besides facilitating target cell-specific replication, removal of endogenous TREs also provides greater insert capacity in a vector, which may be of special concern if an adenoviral vector is to be packaged within a vims particle. Even more importantly, deletion of endogenous TREs prevents the possibility of a recombination event whereby a heterologous TRE is deleted and the endogenous TRE assumes franscriptional control of its respective adenovims coding sequences (thus allowing nonspecific replication). In one embodiment, an adenoviral vector is constructed such that the endogenous transcription confrol sequences of adenoviral genes are deleted and replaced by one or more heterologous TREs. However, endogenous TREs can be maintained in the adenovirus vector(s), provided that sufficient cell-specific replication preference is preserved. These embodiments are constructed by inserting heterologous TREs between an endogenous TRE and a replication gene coding segment. Requisite cell-specific replication preference is determined by conducting assays that compare replication ofthe adenovims vector in a cell which allows function ofthe heterologous TREs with replication in a cell which does not. Generally, a TRE will increase replication of a vector in a target cell by at least about 2-fold, preferably at least about 5-fold, preferably at least about 10-fold more preferably at least about 20-fold, more preferably at least about 50-fold, more preferably at least about 100-fold, more preferably at least about 200-fold, even more preferably at least about 400- to about 500- fold, even more preferably at least about 1000-fold, compared to basal levels of replication in the absence of a TRE. The acceptable differential can be determined empirically (by measurement of mRNA levels using, for example, RNA blot assays, RNase protection assays or other assays known in the art) and will depend upon the anticipated use ofthe vector and/or the desired result. Replication-competent adenovirus vectors directed at specific target cells can be generated using TREs that are preferentially functional in a target cell. In one embodiment ofthe present invention, the target cell is a tumor cell. Non-limiting examples of tumor cell-specific heterologous TREs, and their respective target cells, include: probasin (PB), target cell, prostate cancer (PCT/US98/04132); α-fetoprotein {AFP), target cell liver cancer (PCT/US98/04084); mucin-like glycoprotein DF3 {MUCl), target cell, breast carcinoma (PCT/US98/04080); carcinoembryonic antigen {CEA), target cells, colorectal, gastric, pancreatic, breast, and lung cancers (PCT/US98/04133); plasminogen activator urokinase {uPA) and its receptor gene, target cells, breast, colon, and liver cancers (PCT/US98/04080); E2F1 (cell cycle S-phase specific promoter); target cell, tumors with disrapted retinoblastoma gene function, and HES-2/neu {c-erbB2/neu), target cell, breast, ovarian, stomach, and lung cancers (PCT/US98/04080); tyrosinase, target cell, melanoma cells as described herein and uroplakins, target cell, bladder cells as described herein. Methods for identification, isolation, characterization and utilization of additional target cell-specific TREs are readily available to those of skill in the art. In addition, tumor-specific TREs can be used in conjunction with tissue-specific TREs from the following exemplary genes (tissue in which the TREs are specifically functional are in parentheses): hypoxia responsive element, vascular endothelial growth factor receptor (endothelium), albumin (liver), factor VII (liver), fatty acid synthase (liver), Von Willebrand factor (brain endothelium), alpha-actin and myosin heavy chain (both in smooth muscle), synthetase I (small intestine) Na + -K + -Cl " fransporter (kidney). Additional tissue-specific TREs are known in the art. In one embodiment ofthe present invention, a target cell-specific, heterologous TRE is tumor cell-specific. A vector can comprise a single tumor cell-specific TRE or multiple heterologous TREs which are tumor cell-specific and functional in the same cell. In another embodiment, a vector comprises one or more heterologous TREs which are tumor cell-specific and additionally comprises one or more heterologous TREs which are tissue specific, whereby all TREs are functional in the same cell. Prostate-specific TREs In one embodiment, adenovirus vectors comprise heterologous TREs that are prostate cell specific. For example, TREs that function preferentially in prostate cells and can be used to target adenovirus replication to prostate neoplasia, include, but are not limited to, TREs derived from the prostate-specific antigen gene (E&4-TRE) (Henderson U.S. Patent No. 5,698,443); the glandular kallikrein-1 gene (from the human gene, hKLK2- TRE) (PCT US98/16312), and the probasin gene (E5-TRE) (PCT/US98/04132). All three of these genes are preferentially expressed in prostate cells and their expression is androgen-inducible. Generally, expression of genes responsive to androgen induction is mediated by an androgen receptor (AR). Prostate-specific Antigen (PSA) PSA is synthesized exclusively in prostatic epithelial cells and is synthesized in these cells whether they are normal, hyperplastic, or malignant. This tissue-specific expression of PSA has made it an excellent biomarker for benign prostatic hyperplasia (BPH) and prostatic carcinoma (CaP). Normal serum levels of PSA are typically below 5 ng/ml, with elevated levels indicative of BPH or CaP. Lundwall et al. (1987) FEBS Lett. 214:317; Lundwall (1989) Biochem. Biophys. Ses. Comm. 161:1151; and Riegmann et al. (1991) Molec. Endocrin. 5:1921. The region of the PSA gene that provides androgen-dependent cell specificity, particularly in prostate cells, involves approximately 6.0 kilobases (kb). Schuur et al. (1996) J Biol. Chem. 271:7043-7051. An enhancer region of approximately 1.5 kb in humans is located between nt -5322 and nt -3739, relative to the franscription start site of the PSA gene. Within these enhancer sequences is an androgen response element (ARE) a sequence which binds androgen receptor. The sequence coordinates ofthe PSA promoter are from about nt -540 to nt +8 relative to the franscription start site. Juxtapositioning of the enhancer and promoter yields a fully functional, minimal prostate-specific TRE (E&4-TRE). Other portions of this approximately 6.0 kb region ofthe PSA gene can be used in the vectors described herein, as long as requisite functionality is maintained. Human glandular Kallikrein (hKLK2) Human glandular kallikrein {hKLK2, encoding the hK2 protein) is expressed exclusively in the prostate and its expression is up-regulated by androgens, primarily through transcriptional activation. Wolf et al. (1992) Molec. Endocrinol. 6:753-762; Morris (1989) Clin. Exp. Pharm. Physiol. 16:345-351; Qui et al. (1990) J. Urol. 144:1550- 1556; and Young et al. (1992) Biochem. 31:818-824. The levels of hK2 found in various tumors and in the serum of patients with prostate cancer indicate that hK2 antigen may be a significant marker for prostate cancer. Charlesworth et al. (1997) Urology 49:487-493. Expression of hK2 has been detected in each of 257 radical prostatectomy specimens analyzed. Darson et al. (1997) Urology 49:857-862. The intensity and extent of hK2 expression, detected using specific antibodies, was observed to increase from benign epithelium to high-grade prostatic intraepithelial neoplasia (PIN) and adenocarcinoma. The activity ofthe hKLK2 promoter has been described and a region up to nt -2256 relative to the franscription start site was previously disclosed. Schedlich et al. (1987) DNA 6:429-437. The hKLK2 promoter is androgen responsive and, in plasmid constructs wherein the promoter alone controls the expression of a reporter gene, expression ofthe reporter gene is increased approximately 10-fold in the presence of androgen. Murtha et al. (1993) Biochem. 32:6459-6464. hKLK2 enhancer activity is found within a polynucleotide sequence approximately nt -12,014 to nt -2257 relative to the start of franscription and, when this sequence is operably linked to an hKLK2 promoter and a reporter gene, franscription of operably-linked sequences in prostate cells increases in the presence of androgen to levels approximately 30-fold to approximately 100-fold greater than the level of transcription in the absence of androgen. This induction is generally independent ofthe orientation and position ofthe enhancer sequences. Enhancer activity has also been demonstrated in the following regions (all relative to the franscription start site): about nt -3993 to about nt -3643, about nt -4814 to about nt -3643, about nt -5155 to about nt -3387, about nt -6038 to about nt -2394. Thus, a hKLK2 enhancer can be operably linked to an hKLK2 promoter or a heterologous promoter to form a hKLK2 franscriptional regulatory element {hKLK2-TKE). A hKLK2-TKE can then be operably linked to a heterologous polynucleotide to confer /T^-L -TRE-specific franscriptional regulation on the linked gene, thus increasing its expression. Probasin The rat probasin {PB) gene encodes an androgen and zinc-regulated protein first characterized in the dorsolateral prostate ofthe rat. Dodd et al. (1983) J. Biol. Chem. 258:10731-10737; Mattisik et α/. (1986) Biochem. Cell. Biol. 64:601-607; and Sweefland et al. (1988) Mol. Cell. Biochem. 84:3-15. The dorsolateral lobes ofthe murine prostate are considered the most homologous to the peripheral zone ofthe human prostate, where approximately 68% of human prostate cancers are thought to originate. A E5-TRE has been shown to exist in an approximately 0.5 kb fragment of sequence upstream ofthe probasin coding sequence, from about nt -426 to about nt +28 relative to the franscription start site. This mimmal promoter sequence from the PB gene appears to provide sufficient information to direct prostate-specific developmental- and hormone -regulated expression of an operably linked heterologous gene in transgenic mice. Greenberg et al. (1994) Mol Endocrinol 8:230-239. Alpha-fetoprotein α-fetoprotein (AFP) is an oncofetal protein, the expression of which is primarily restricted to developing tissues of endodermal origin (yolk sac, fetal liver, and gut), although the level of its expression varies greatly depending on the tissue and the developmental stage. AFP is of clinical interest because the serum concentration of AFP is elevated in a majority of hepatoma patients, with high levels of AFP found in patients with advanced disease. High serum AFP levels in patients appear to be due to AFP expression in hepatocellular carcinoma (HCC), but not in surrounding normal liver. Thus, expression ofthe AFP gene appears to be characteristic of hepatoma cells. An AFP-TRE is described in for example PCT/US98/04084. According to published reports, the AFP-TRE is responsive to cellular proteins (franscription factors and/or co-factor(s)) associated with AFP-producing cells, such as AFP-binding protein (see, for example, U.S. Pat. No. 5,302,698) and comprises at least a portion of an AFP promoter and/or an AFP enhancer. Cell-specific TREs from the AFP gene have been identified. For example, the cloning and characterization of human AFP- specific enhancer activity is described in Watanabe et al. (1987) J. Biol. Chem. 262:4812- 4818. A 5' AFP regulatory region (containing the promoter, putative silencer, and enhancer) is contained within approximately 5 kb upsfream from the transcription start site. Within the AFP regulatory region, a human AFP enhancer region is located between about nt -3954 and about nt -3335, relative to the franscription start site ofthe AFP gene. The human AFP promoter encompasses a region from about nt -174 to about nt +29. Juxtapositioning of these two genetic elements, yields a fully functional AFP-TRE. Ido et al. (1995) Cancer Ses. 55:3105-3109 describe a 259 bp promoter fragment (nt -230 to nt +29) that is specific for expression in HCC cells. The AFP enhancer, located between nt -3954 and nt -3335 relative to the franscription start site, contains two regions, denoted A and B. The promoter region contains typical TATA and CAAT boxes. Preferably, the ^EE-TRE contains at least one enhancer region. More preferably, the .4EE-TRE contains both enhancer regions. Suitable target cells for vectors containing AFP-TREs are any cell type that allow an AFP-TRE to function. Preferred are cells that express or produce AFP, including, but not limited to, tumor cells expressing AFP. Examples of such cells are hepatocellular carcinoma (HCC) cells, gonadal and other germ cell tumors (especially endodermal sinus tumors), brain tumor cells, ovarian tumor cells, acinar cell carcinoma ofthe pancreas (Kawamoto et al. (1992) Hepatogastroenterology 39:282-286), primary gall bladder tumor (Katsuragi et al. (1989) Sinsko Hoshasen 34:371-374), uterine endomefrial adenocarcinoma cells (Koyama et al. (1996) Jpn. J. Cancer Ses. 87:612-617), and any metastases ofthe foregoing (which can occur in lung, adrenal gland, bone marrow, and/or spleen). In some cases, metastatic disease to the liver from certain pancreatic and stomach cancers produce AFP. Especially preferred as target cells for an AFP-TRE are hepatocellular carcinoma cells and any of their metastases. AFP production can be measured (and hence AFP-producing cells can be identified) using immunoassays standard in the art, such as RIA, ELISA or protein immunoblotting (Western blots) to determine levels of AFP protein production; and/or RNA blotting (Northern blots) to determine AFP mRNA levels. Alternatively, such cells can be identified and/or characterized by their ability to activate franscriptionally an ^ 4EE-TRE {i.e., allow an AFP-TRE to function). See also co-owned PCT W098/39465 regarding AFP-TREs. As described in more detail therein, an AFP-TRE can comprise any number of configurations, including, but not limited to, an AFP promoter; an AFP enhancer; an AFP promoter and an AFP enhancer; an AFP promoter and a heterologous enhancer; a heterologous promoter and an AFP enhancer; and multimers ofthe foregoing. The promoter and enhancer components of an AFP-TRE can be in any orientation and/or distance from the coding sequence of interest, as long as the desired AFP cell-specific transcriptional activity is obtained. An adenovims vector ofthe present invention can comprise an AFP-TRE endogenous silencer element or the AFP-TRE endogenous silencer element can be deleted. Urokinase Plasminogen Activator The protein urokinase plasminogen activator (uPA) and its cell surface receptor, urokinase plasminogen activator receptor (uPAR), are expressed in many ofthe most frequently-occurring neoplasms and appear to represent important proteins in cancer metastasis. Both proteins are implicated in breast, colon, prostate, liver, renal, lung and ovarian cancer. Sequence elements that regulate uPA and uPAR franscription have been extensively studied. Riccio et al. (1985) Nucleic Acids Ses. 13:2759-2771; Cannio et al. (1991) Nucleic Acids Res. 19:2303-2308. Carcinoembryonic antigen (CEA) CEA is a 180,000 Dalton, tumor-associated, glycoprotein antigen present on endodermally-derived neoplasms ofthe gastrointestinal fract, such as colorectal, gastric (stomach) and pancreatic cancer, as well as other adenocarcinomas such as breast and lung cancers. CEA is of clinical interest because circulating CEA can be detected in the great majority of patients with CEA-positive tumors. In lung cancer, about 50% of total cases have circulating CEA, with high concentrations of CEA (greater than 20 ng/ml) often detected in adenocarcinomas. Approximately 50% of patients with gastric carcinoma are serologically positive for CEA. The 5 '-flanking sequence ofthe CEA gene has been shown to confer cell-specific activity. The CEA promoter region, approximately the first 424 nucleotides upsfream of the transcriptional start site in the 5' flanking region ofthe gene, was shown to confer cell- specific activity by virtue of providing higher promoter activity in CEA-producing cells than in non-producing HeLa cells. Schrewe tα/. (1990) Mol. Cell. Biol. 10:2738-2748. In addition, cell-specific enhancer regions have been found. See PCT/GB/02546 The CEA promoter, putative silencer, and enhancer elements appears to be contained within a region that extends approximately 14.5 kb upsfream from the franscription start site. Richards et al. (1995); PCT/GB/02546. Further characterization ofthe 5'-flanking region ofthe CEA gene by Richards et al. (1995) supra indicated that two upsfream regions (one between about -13.6 and about -10.7 kb, and the other between about -6.1 and about-4.0 kb), when linked to the multimerized promoter, resulted in high-level and selective expression of a reporter construct in CEA-producing LoVo and SW1463 cells. Richards et al. (1995) supra also localized the promoter region between about nt -90 and about nt +69 relative to the franscriptional start site, with the region between about nt -41 and about nt -18 being essential for expression. PCT/GB/02546 describes a series of 5 '-flanking CEA fragments which confer cell-specific activity, including fragments comprising the following sequences: about nt -299 to about nt +69; about nt -90 to about nt +69; nt -14,500 to nt -10,600; nt -13,600 to nt -10,600; and nt -6100 to nt -3800, with all coordinates being relative to the transcriptional start point. In addition, cell-specific franscription activity is conferred on an operably linked gene by the CEA fragment from nt -402 to nt +69. CEA-TREs for use in the vectors disclosed herein are derived from mammalian cells, including, but not limited to, human cells. Thus, any ofthe CE-4-TREs can be used as long as the requisite desired functionality is displayed by the vector. Mucin The protein product ofthe MUCl gene (known as mucin, MUCl protein; episialin; polymorphic epithelial mucin or PEM; EMA; DF3 antigen; NPGP; PAS-O; or CA15.3 antigen) is normally expressed mainly at the apical surface of epithelial cells lining the glands or ducts ofthe stomach, pancreas, lungs, trachea, kidney, uterus, salivary glands, and mammary glands. Zotter et al. (1988) Cancer Rev. 11-12:55-101; and Girling et al. (1989) Int. J. Cancer 43:1072-1076. However, mucin is overexpressed in 75-90% of human breast carcinomas. Kufe et α/. (1984) Hybridoma 3:223-232. For reviews, see Hilkens (1988) Cancer Rev. 11-12:25-54; and Taylor-Papadimifriou, et al. (1990) J Nucl. Med. Allied Sci. 34:144-150. Mucin protein expression correlates with the degree of breast tumor differentiation. Lundy t α/. (1985) Breast Cancer Res. Treat. 5:269-276. Overexpression ofthe MUCl gene in human breast carcinoma cells MCF-7 and ZR-75-1 appears to occur at the franscriptional level. Kufe et al. (1984) supra; Kovarik (1993) J. Biol. Chem. 268:9917-9926; and Abe et al. (1990) J. Cell. Physiol. 143:226- 231. The regulatory sequences ofthe MUCl gene have been cloned, including the approximately 0.9 kb upsfream ofthe franscription start site which contains a TRE that appears to be involved in cell-specific franscription. Abe et al. (1993) Proc. Natl. Acad. Sci. USA 90:282-286; Kovarik et al. (1993) supra; and Kovarik et al. (1996) J Biol. Chem. 271:18140-18147. MUCl -TREs are derived from mammalian cells, including but not limited to, human cells. Preferably, the MUC1-TRE is human. In one embodiment, the MUC1-TRE contains the entire 0.9 kb 5' flanking sequence ofthe MUCl gene. In other embodiments, MUCl -TREs comprise the following sequences (relative to the franscription start site ofthe MUCl gene) operably-linked to a promoter: about nt -725 to about nt +31, about nt -743 to about nt +33, about nt -750 to about nt +33, and about nt -598 to about nt +485. c-erbB2/HER- /neu The c-erbB2/neu gene {HES-2/neu or HER) is a transforming gene that encodes a 185 kD epidermal growth factor receptor-related transmembrane glycoprotein. In humans, the c-erbB2/neu protein is expressed during fetal development and, in adults, the protein is weakly detectable (by immunohistochemistry) in the epithelium of many normal tissues. Amplification and/or over-expression ofthe c-erbB2/neu gene has been associated with many human cancers, including breast, ovarian, uterine, prostate, stomach and lung cancers. The clinical consequences of overexpression ofthe c-erbB2/neu protein have been best studied in breast and ovarian cancer. c-erbB2/neu protein over-expression occurs in 20 to 40% of intraductal carcinomas ofthe breast and 30% of ovarian cancers, and is associated with a poor prognosis in subcategories of both diseases. Human, rat and mouse c-erbB2/neu TREs have been identified and shown to confer transcriptional activity specific to c-erb52/«ew-expressing cells. Tal et al. (1987) Mol. Cell. Biol. 7:2597-2601; Hudson et al. (1990) J Biol. Chem. 265:4389-4393; Grooteclaes et al. (1994) Cancer Ses. 54:4193-4199; Ishii et al. (1987) Proc. Natl. Acad. Sci. USA 84:4374-4378; and Scott etal. (1994) J. Biol. Chem. 269:19848-19858. Melanocyte-specific TRΕ It has been shown that some genes which encode melanoma proteins are frequently expressed in melanoma/melanocytes, but silent in the majority of normal tissues.. A variety of melanocyte-specific TRΕ are known, are responsive to cellular proteins (franscription factors and/or co-factor(s)) associated with melanocytes, and comprise at least a portion of a melanocyte-specific promoter and/or a melanocyte-specific enhancer. Known franscription factors that confrol expression of one or more melanocyte-specific genes include the microphthalmia associated franscription factor MITF. Yasumoto et al. (1997) J Biol. Chem. 272:503-509. Other franscription factors that control expression of one or more melanocyte specific genes include MART-1/Melan-A, gplOO, TRP-1 and TRP-2 Methods are described herein for measuring the activity of a melanocyte-specific TRΕ and thus for determining whether a given cell allows a melanocyte-specific TRΕ to function. In some embodiments, the melanocyte-specific TREs used in this invention are derived from mammalian cells, including but not limited to, human, rat, and mouse. Any melanocyte-specific TREs may be used in the adenoviral vectors ofthe invention. Rodent and human 5' flanking sequences from genes expressed specifically or preferentially in melanoma cells have been described in the literature and are thus made available for practice of this invention and need not be described in detail herein. The following are some examples of melanocyte-specific TREs which can be used. A promoter and other confrol elements in the human tyrosinase gene 5' flanking region have been described and sequences have been deposited as GenBank Accession Nos. XI 6073 and D 10751. Kikuchi et al. (1989) Biochim. Biophys. Acta 1009:283-286; and Shibata et al. (1992) J. Biol Chem. 267:20584-20588. A cis-acting element has been defined that enhances melanocyte- specific expression of human tyrosinase gene. This element comprises a 20-bp sequence known as tyrosinase distal element (TDE), contains a CATGTG motif, and lies at positions about -1874 to about -1835 relative to the human tyrosinase gene franscription start site. Yasumoto et al. (1994) Mol. Cell. Biol. 14:8058-8070. A promoter region comprising sequences from about -209 to +61 ofthe human tyrosinase gene was found to direct melanocyte-specific expression. Shibata (1992). Similarly, the mouse tyrosinase 5' flanking region has been analyzed and a sequence deposited as GenBank Accession Nos. D00439 and X51743. Klϋppel et al. (1991) Proc. Natl. Acad. Sci. USA 88:3777-3788. A minimal promoter has been identified for the mouse TRP-1 gene, and was reported to encompass nucleotides -44 to +107 relative to the franscription start site. Lowings et al. (1992) Mol. Cell. Biol. 12:3653-3662. Two regulatory regions required for melanocyte- specific expression ofthe human TRP-2 gene have been identified. Yokoyama et al. (1994) J Biol Chem. 269:27080-27087. A human MART-1 promoter region has been described and deposited as GenBank Accession No. U55231. Melanocyte-specific promoter activity was found in a 233-bp fragment ofthe human MART-1 gene 5' flanking region. Butterfield et al. (1997) Gene 191:129-134. A basic-helix-loop-helix/leucine zipper-containing franscription factor, MITF (microphfhalmia associated franscription factor) was reported to be involved in franscriptional activation of tyrosinase and TRP-1 genes. Yasumoto et al. (1997) J. Biol. Chem. 272:503-509. In some embodiments, a melanocyte-specific TRE comprises sequences derived from the 5' flanking region of a human tyrosinase gene depicted in Table 3. In some of these embodiments, the melanocyte-specific TRE comprises tyrosinase nucleotides from about -231 to about +65 relative to the franscription start site (from about nucleotide 244 to about nucleotide 546 of SEQ ID NO: 10) and may further comprise nucleotides from about -1956 to about -1716 relative to the human tyrosinase franscription start site (from about nucleotide 6 to about nucleotide 243 of SEQ ID NO: 10). A melanocyte-specific TRE can comprise nucleotides from about — 231 to about + 65 juxtaposed to nucleotides from about -1956 to about -1716. It has been reported that nucleotides from about -1956 to about - 1716 relative to the human tyrosinase transcription start site can confer melanocyte-specific expression of an operably linked reporter gene with either a homologous or a heterologous promoter. Accordingly, in some embodiments, a melanocyte-specific TRE comprises nucleotides from about -1956 to about -1716 operably linked to a heterologous promoter. A melanocyte-specific TRE can also comprise multimers. For example, a melanocyte-specific TRE can comprise a tandem series of at least two, at least three, at least four, or at least five tyrosinase promoter fragments. Alternatively, a melanocyte- specific TRE could have one or more tyrosinase promoter regions along with one or more tyrosinase enhancer regions. These multimers may also contain heterologous promoter and/or enhancer sequences. Cell status-specific TREs Cell status-specific TREs for use in the adenoviral vectors ofthe present invention can be derived from any species, preferably a mammal. A number of genes have been described which are expressed in response to, or in association with, a cell status. Any of these cell status-associated genes may be used to generate a cell status-specific TRE. An example of a cell status is cell cycle. An exemplary gene whose expression is associated with cell cycle is E2F-1, a ubiquitously expressed, growth-regulated gene, which exhibits peak franscriptional activity in S phase. Johnson et al. (1994) Genes Dev. 8:1514- 1525. The RB protein, as well as other members ofthe RB family, form specific complexes with E2F-1, thereby inhibiting its ability to activate franscription. Thus, E2F-1- responsive promoters are down-regulated by RB. Many tumor cells have disrapted RB function, which can lead to de-repression of E2F-1 -responsive promoters, and, in turn, deregulated cell division. Accordingly, in one embodiment, the invention provides an E3-containing adenoviral vector in which an adenoviral gene (preferably a gene necessary for replication) is under franscriptional confrol of a cell status-specific TRE, wherein the cell status-specific TRE comprises a cell cycle-activated TRE. In one embodiment, the cell cycle-activated TRE is an E2Fl TRE. Another group of genes that are regulated by cell status are those whose expression is increased in response to hypoxic conditions. Bunn and Poyton (1996) Physiol. Rev. 76:839-885; Dachs and Stratford (1996) Br. J. Cancer 74:5126-5132; Guillemin and Krasnow (1997) Cell 89:9-12. Many tumors have insufficient blood supply, due in part to the fact that tumor cells typically grow faster than the endothelial cells that make up the blood vessels, resulting in areas of hypoxia in the tumor. Folkman (1989) J. Natl. Cancer Inst. 82:4-6; and Kallinowski (1996) The Cancer J. 9:37-40. An important mediator of hypoxic responses is the franscriptional complex HIF- 1 , or hypoxia inducible factor- 1 , which interacts with a hypoxia-responsive element (HRE) in the regulatory regions of several genes, including vascular endothelial growth factor, and several genes encoding glycolytic enzymes, including enolase-1. Murine HRE sequences have been identified and characterized. Firth et al. (1994) Proc. Natl Acad. Sci. USA 91:6496-6500. An HRE from a rat enolase-1 promoter is described in Jiang et al. (1997) Cancer Ses. 57:5328-5335. An HRE from a rat enolase-1 promoter is depicted in Table 3. Accordingly, in one embodiment, an adenovirus vector comprises an adenovirus gene, preferably an adenoviral gene essential for replication, under franscriptional confrol of a cell status-specific TRE comprising an HRE. In one embodiment, the cell status- specific TRE comprises the HRE depicted in Table 3. Other cell status-specific TREs include heat-inducible (i.e., heat shock) promoters, and promoters responsive to radiation exposure, including ionizing radiation and UV radiation. For example, the promoter region ofthe early growth response- 1 (Egr-1) gene contains an element(s) inducible by ionizing radiation. Hallahan et al. (1995) Nat. Med. 1 :786-791; and Tsai-Morris et al. (1988) Nucl. Acids. Ses. 16:8835-8846. Heat-inducible promoters, including heat-inducible elements, have been described. See, for example Welsh (1990) in "Stress Proteins in Biology and Medicine", Morimoto, Tisseres, and Georgopoulos, eds. Cold Spring Harbor Laboratory Press; and Perisic et al. (1989) Cell 59:797-806. Accordingly, in some embodiments, the cell status-specific TRE comprises an element(s) responsive to ionizing radiation. In one embodiment, this TRE comprises a 5' flanking sequence of an Egr-1 gene. In other embodiments, the cell status-specific TRE comprises a heat shock responsive element. The cell status-specific TREs listed above are provided as non-limiting examples of TREs that would function in the instant invention. Additional cell status-specific TREs are known in the art, as are methods to identify and test cell status specificity of suspected cell status-specific TREs. Urothelial cell-specific TSEs Any urothelial cell-specific TRE may be used in the adenoviral vectors ofthe invention. A number of urothelial cell-specific proteins have been described, among which are the uroplakins. Uroplakins (UP), including UPIa and UPIb (27 and 28 kDa, respectively), UPII (15 kDa), and UPIII (47 kDa), are members of a group of integral membrane proteins that are major proteins of urothelial plaques. These plaques cover a large portion ofthe apical surface of mammalian urothelium and may play a role as a permeability barrier and/or as a physical stabilizer ofthe urothelial apical surface. Wu et al. (1994) J Biol. Chem. 269 3116-13124. UPs are bladder-specific proteins, and are expressed on a significant proportion of urothelial-derived tumors, including about 88% of fransitional cell carcinomas. Moll et al. (1995) Am. J. Pathol. 147:1383-1397; and Wu et al. (1998) Cancer Ses. 58:1291-1297. The confrol ofthe expression ofthe human UPII has been studied, and a 3.6-kb region upstream ofthe mouse UPII gene has been identified which can confer urothelial-specific franscription on heterologous genes (Lin et al. (1995) Proc. Natl. Acad. Sci. USA 92:679-683). Preferred urothelial cell-specific TREs include TREs derived from the uroplakins UPIa, UPIb, UPII, and UPIII, as well as urohingin. A uroplakin TRE may be from any species, depending on the intended use ofthe adenovirus, as well as the requisite functionality is exhibited in the target or host cell. Significantly, adenovirus constructs comprising a urothelial cell-specific TREs have observed that such constructs are capable of selectively replicating in urothelial cells as opposed to smooth muscle cells, which adjoin urothelial cells in the bladder. Uroplakin Urothelial-specific TREs derived from the h UPII gene are described herein. Accordingly, in some embodiments, an adenovims vector ofthe invention comprises an adenovims gene, preferably an adenoviral gene essential for replication, under transcriptional confrol of a urothelial cell-specific TRE which comprises the 2.2 kb sequence from the 5' flanking region of hUPII gene, as shown in Table 3. In other embodiments, an adenovirus vector ofthe invention comprises an adenovirus gene, preferably an adenoviral gene essential for replication, under transcriptional confrol of a urothelial cell-specific TRE which comprises a 1.8 kb sequence from the 5' flanking region of hUPII gene, from nucleotides 430 to 2239 as shown in Table 3. In other embodiments, the urothelial cell-specific TRE comprises a functional portion ofthe 2.2 kb sequence depicted in Table 3, or a functional portion ofthe 1.8 kb sequence of nucleotides 430 to 2239 ofthe sequence depicted in Table 3, such as a fragment of 2000 bp or less, 1500 bp or less, or 1000 bp or less, 600 bp less, or at least 200 bp which includes the 200 bp fragment ofthe hUPII 5 '-flanking region. A 3.6 kb 5 '-flanking sequence located from the mouse UPII (mUPII) gene which confers urothelial cell-specific franscription on heterologous genes is one urothelial cell- specific TRE useful in vectors ofthe instant invention (Table 3). Smaller TREs {i.e., 3500 bp or less, more preferably less than about 2000 bp, 1500 bp, or 1000 bp) are preferred. Smaller TREs derived from the mUPII 3.6 kb fragment are one group of preferred urothelial cell-specific TREs. In particular, Inventors have identified an approximately 600 bp fragment from the 5 ' flanking DNA of the mUPII gene, which contains 540 bp of 5 ' untranslated region (UTR) ofthe mUPII gene, that confers urothelial cell-specific expression on heterologous genes. Accordingly, in some embodiments, an adenovirus vector ofthe invention comprises an adenovirus gene, preferably an adenoviral gene essential for replication, under franscriptional confrol of a urothelial cell-specific TRE which comprises the 3.6 kb sequence from the 5' flanking region of mouse UPII gene, as shown in Table 3. In other embodiments, the urothelial cell-specific TRE comprises a functional portion ofthe 3.6 kb sequence depicted in Table 3, such as a fragment of 3500 bp or less, 2000 bp or less, 1500 bp or less, or 1000 bp or less which includes the 540 bp fragment of 5' UTR. The ' urothelial cell-specific TRE may also be a sequence which is substantially identical to the 3.6 kb mUPII 5'-flanking region or any ofthe described fragments thereof. As an example of how urothelial cell-specific TRE activity can be determined, a polynucleotide sequence or set of such sequences can be generated using methods known in the art, such as chemical synthesis, site-directed mutagenesis, PCR, and/or recombinant methods. The sequence(s) to be tested is inserted into a vector containing an appropriate reporter gene, including, but not limited to, chloramphenicol acetyl fransferase (CAT), β- galactosidase (encoded by the lacZ gene), luciferase (encoded by the luc gene), a green fluorescent protein, alkaline phosphatase, and horse radish peroxidase. Such vectors and assays are readily available, from, inter alia, commercial sources. Plasmids thus constructed are fransfected into a suitable host cell to test for expression ofthe reporter gene as controlled by the putative target cell-specific TRE using transfection methods known in the art, such as calcium phosphate precipitation, electroporation, liposomes (Upofection) and DEAE dexfran. Suitable host cells include any urothelial cell type, including but not limited to, KU-1, MYP3 (a non-tumorigenic rat urothelial cell line), 804G (rat bladder carcinoma cell line), cultured human urothelial cells (HUC), HCV-29, UM-UC-3, SW780, RT4, HL60, KG-1, and KG-1A. Non-urothelial cells, such as LNCaP, HBL-100, HLF, HLE, 3T3, Hep3B, HuH7, CADO-LC9, and HeLa are used as a confrol. Results are obtained by measuring the level of expression ofthe reporter gene using standard assays. Comparison of expression between urothelial cells and confrol indicates presence or absence of franscriptional activation. Comparisons between or among various urothelial cell-specific TREs can be assessed by measuring and comparing levels of expression within a single urothelial cell Une. It is understood that absolute transcriptional activity of a urothelial cell-specific TRE will depend on several factors, such as the nature ofthe target cell, delivery mode and form ofthe urothelial cell-specific TRE, and the coding sequence that is to be selectively franscriptionally activated. To compensate for various plasmid sizes used, activities can be expressed as relative activity per mole of fransfected plasmid. Alternatively, the level of franscription (i.e., mRNA) can be measured using standard Northern analysis and hybridization techniques. Levels of transfection (i.e., transfection efficiencies) are measured by co-fransfecting a plasmid encoding a different reporter gene under confrol of a different TRE, such as the CMV immediate early promoter. This analysis can also indicate negative regulatory regions, i.e., silencers. Alternatively a putative urothelial cell-specific TRE can be assessed for its ability to confer adenoviral replication preference for cells that allow a urothelial cell-specific TRE to function. For this assay, constructs containing an adenovims gene essential to replication operatively linked to a putative urothelial cell-specific TRE are transfected into urothelial cells. Viral replication in those cells is compared, for example, to viral replication by wild type adenovims in those cells and/or viral replication by the construct in non-urothelial cells. TSE configurations A TRE as used in the present invention can be present in a variety of configurations. A TRE can comprise multimers. For example, a TRE can comprise a tandem series of at least two, at least three, at least four, or at least five target cell-specific TREs. These multimers may also contain heterologous promoter and/or enhancer sequences. Optionally, a transcriptional terminator or franscriptional "silencer" can be placed upstream ofthe target cell-specific TRE, thus preventing unwanted read-through franscription ofthe coding segment under franscriptional confrol ofthe target cell-specific TRE. Also, optionally, the endogenous promoter ofthe coding segment to be placed under transcriptional confrol of the target cell-specific TRE can be deleted. A target cell-specific TRE may or may not lack a silencer. The presence of a silencer (i.e., a negative regulatory element) may assist in shutting off franscription (and thus replication) in non-permissive cells (i.e., a non-target cell). Thus, presence of a silencer may confer enhanced target cell-specific replication by more effectively preventing adenoviral vector replication in non-target cells. Alternatively, lack of a silencer may assist in effecting replication in target cells, thus conferring enhanced target cell-specific replication due to more effective replication in target cells. It is also understood that the invention includes a target cell-specific TRE regulating the franscription of a bicisfronic mRNA in which translation ofthe second mRNA is associated by an IRES. An adenovims vector may further include an additional heterologous TRE which may or may not be operably linked to the same gene(s) as the target cell-specific TRE. For example a TRE (such as a cell type-specific or cell status- specific TRE) may be juxtaposed to a second type of target-cell-specific TRE. "Juxtaposed" means a target cell-specific TRE and a second TRE franscriptionally control the same gene. For these embodiments, the target cell-specific TRE and the second TRE may be in any of a number of configurations, including, but not limited to, (a) next to each other (i.e., abutting); (b) both 5' to the gene that is transcriptionally controlled (i.e., may have intervening sequences between them); (c) one TRE 5' and the other TRE 3' to the gene. As is readily appreciated by one skilled in the art, a target cell-specific TRE is a polynucleotide sequence, and, as such, can exhibit function over a variety of sequence permutations. Methods of nucleotide substitution, addition, and deletion are known in the art, and readily available functional assays (such as the CAT or luciferase reporter gene assay) allow one of ordinary skill to determine whether a sequence variant exhibits requisite target cell-specific franscription function. Hence, the invention also includes functionally-preserved variants ofthe TRE nucleic acid sequences disclosed herein, which include nucleic acid substitutions, additions, and/or deletions. The variants ofthe sequences disclosed herein may be 80%, 85%, 90%, 95%, 98%, 99% or more identical, as measured by, for example, ALIGN Plus (Scientific and Educational Software, Pennsylvania), preferably using efault parameters, which are as follows: mismatch = 2; open gap = 0; extend gap = 2 to any ofthe urothelial cell-specific TRE sequences disclosed herein. Variants of target cell-specific TRE sequences may also hybridize at high sfringency, that is at 68°C and 0.1X SSC, to any ofthe target cell-specific TRE sequences disclosed herein. In terms of hybridization conditions, the higher the sequence identity required, the more stringent are the hybridization conditions if such sequences are determined by their ability to hybridize to a sequence of TRE disclosed herein. Accordingly, the invention also includes polynucleotides that are able to hybridize to a sequence comprising at least about 15 contiguous nucleotides (or more, such as about 25, 35, 50, 75 or 100 contiguous nucleotides) of a TRE disclosed herein. The hybridization conditions would be stringent, i.e., 80°C (or higher temperature) and 6M SSC (or less concentrated SSC). Another set of stringent hybridization conditions is 68°C and 0.1 X SSC. For discussion regarding hybridization reactions, see below. Hybridization reactions can be performed under conditions of different "sfringency". Conditions that increase stringency of a hybridization reaction of widely known and published in the art. See, for example, Sambrook et al. (1989) at page 7.52. Examples of relevant conditions include (in order of increasing sfringency): incubation temperatures of 25°C, 37°C, 50°C and 68°C; buffer concenfrations of 10 X SSC, 6 X SSC, 1 X SSC, 0.1 X SSC (where SSC is 0.15 M NaCl and 15 mM citrate buffer) and their equivalents using other buffer systems; formamide concentrations of 0%, 25%, 50%, and 75%; incubation times from 5 minutes to 24 hours; 1, 2, or more washing steps; wash incubation times of 1, 2, or 15 minutes; and wash solutions of 6 X SSC, 1 X SSC, 0.1 X SSC, or deionized water. An exemplary set of stringent hybridization conditions is 68°C and 0.1 X SSC. "T m " is the temperature in degrees Celcius at which 50% of a polynucleotide duplex made of complementary strands hydrogen bonded in anti-parallel direction by Watson- Crick base pairing dissociates into single strands under conditions ofthe experiment. T m may be predicted according to a standard formula, such as: T m = 81.5 + 16.6 log[X + ] + 0.41 (%G/C) - 0.61 (%F) - 600/L where [X*] is the cation concenfration (usually sodium ion, Na + ) in mol/L; (%G/C) is the number of G and C residues as a percentage of total residues in the duplex; (%F) is the percent formamide in solution (wt/vol); and L is the number of nucleotides in each sfrand ofthe duplex. While not wishing to be bound by a single theory, the inventors note that it is possible that certain modifications will result in modulated resultant expression levels, including enhanced expression levels. Achievement of modulated resultant expression levels, preferably enhanced expression levels, may be especially desirable in the case of certain, more aggressive forms of cancer, or when a more rapid and/or aggressive pattern of cell killing is warranted (due to an immunocompromised condition ofthe individual, for example). Determination ofTSE activity Activity of a TRE can be determined, for example, as follows. A TRE polynucleotide sequence or set of such sequences can be generated using methods known in the art, such as chemical synthesis, site-directed mutagenesis, PCR, and/or recombinant methods. The sequence(s) to be tested can be inserted into a vector containing a promoter (if no promoter element is present in the TRE) and an appropriate reporter gene encoding a reporter protein, including, but not limited to, chloramphemcol acetyl fransferase (CAT), β- galactosidase (encoded by the lacZ gene), luciferase (encoded by the luc gene), alkaline phosphatase (AP), green fluorescent protein (GFP), and horseradish peroxidase (HRP). Such vectors and assays are readily available, from, inter alia, commercial sources. Plasmids thus constructed are fransfected into a suitable host cell to test for expression of the reporter gene as controlled by the putative TRE using transfection methods known in the art, such as calcium phosphate precipitation, electroporation, liposomes, DEAE dexfran-mediated transfer, particle bombardment or direct injection. TRE activity is measured by detection and/or quantitation of reporter gene-derived mRNA and/or protein. Reporter protein product can be detected directly {e.g., immunochemically) or through its enzymatic activity, if any, using an appropriate substrate. Generally, to determine cell specific activity of a TRE, a TRE-reporter gene construct is introduced into a variety of cell types. The amount of TRE activity is determined in each cell type and compared to that of a reporter gene construct lacking the TRE. A TRE is determined to be cell-specific if it is preferentially functional in one cell type, compared to a different type of cell. Adenovirus early genes The adenoviras vectors ofthe invention comprise two or more genes which are co- transcribed under the confrol of a target cell-specific TRE wherein the second gene is under franslational confrol of an IRES. One or more ofthe genes can be an adenoviras gene, preferably an adenoviras gene essential for replication. Any gene that is essential for adenoviras replication, such as EIA, EIB, E2, E4 or any ofthe late genes, is useful. The adenoviras may also comprise E3. In addition, one or more ofthe genes can be a transgene or heterologous gene. Any ofthe various adenovirus serotypes can be used, such as, for example, Ad2, Ad5, Adl2 and Ad40. For purposes of illustration, the Ad5 serotype is exemplified herein. The EIA gene is expressed immediately (between 0 and 2 hours) after viral infection, before any other viral genes. EIA protein is a trans-acXmg positive transcriptional regulatory factor, and is required for the expression ofthe other early viral genes EIB, E2, E3, E4, and the promoter-proximal major late genes. Despite the nomenclature, the promoter proximal genes driven by the major late promoter are also expressed during early times after Ad5 infection. Flint (1982) Biochem. Biophys. Acta 651:175-208; Flint (1986) Advances Virus Sesearch 31:169-228; and Grand (1987) Biochem. J. 241:25-38. In the absence of a functional EIA gene, viral infection does not proceed, because the gene products necessary for viral DNA replication are not produced. Nevins (1989) Adv. Virus Ses. 31:35-81. The franscription start site of Ad5 EIA is at coordinate 498 and the ATG start site ofthe EIA protein is at coordinate 560 in the viras genome. The EIB protein is necessary in trans for transport of late mRNA from the nucleus to the cytoplasm. Defects in EIB expression result in poor expression of late viral proteins and an inability to shut off host cell protein synthesis. The promoter of EIB has been implicated as the defining element of difference in the host range of Ad40 and Ad5 : clinically Ad40 is an enterovirus, whereas Ad5 causes acute conjunctivitis. Bailey et al. (1993) Virology 193:631; Bailey et al. (1994) Virology 202:695-706. The EIB promoter of Ad5 consists of a single high-affinity recognition site for Spl and a TATA box, and extends from Ad5 nt 1636 to 1701. Adenoviras EIB 19-kDa (19K) protein is a potent inhibitor of apoptosis and cooperates with EIA to produce oncogenic transformation of primary cells (Rao, et al., 1992, Cell Biology, 89:7742-7746). During productive adenoviras infection, EIA stimulates host cell DNA synthesis, thereby causing cells to aberrantly go through the cell cycle. In response to cell cycle deregulation, the host cell undergoes apoptosis. As a defense mechanism, the EIB 19-kDa protein inhibits this ElA-induced apoptosis and allows assembly of viral progeny to be completed before the cell commits suicide. EIB 19- kDa conducts anti-apoptotic function by multiple mechanisms. EIB 19-kDa inhibits the apoptosis of multiple stimuli, including El a, p53 and TNF, for example. According to wild-type Ad5 , the EIB 19-kDa region is located between nucleotide 1714 and nucleotide 2244. The EIB 19-kDa region has been described in, for example, Rao et al, Proc. Natl. Acad. Sci. USA, 89:1142-1146. In a preferred embodiment, expression of the E 1 A and EIB regions of the Ad genome is facilitated in a cell-specific fashion by placing a cell-specific TRE upsfream of EIA and a internal ribosome entry site between EIA and EIB. The E2 region of adenoviras encodes proteins related to replication ofthe adenoviral genome, including the 72 kD DNA-binding protein, the 80 kD precursor terminal protein and the viral DNA polymerase. The E2 region of Ad5 is franscribed in a rightward orientation from two promoters, termed E2 early and E2 late, mapping at 76.0 and 72.0 map units, respectively. While the E2 late promoter is transiently active during late stages of infection and is independent of the EIA fransactivator protein, the E2 early promoter is crucial during the early phases of viral replication. The E2 early promoter of Ad5 is located between nucleotides 27,050 and 27,150, and consists of a major and a minor franscription initiation site (the latter accounting for about 5% of E2 transcripts), two non-canonical TATA boxes, two E2F franscription factor binding sites and an ATF franscription factor binding site. For a detailed review of E2 promoter architecture see Swaminathan et al. (1995) Curr. Topics in Micro, andlmm. 199 part 3:177-194. The E2 late promoter overlaps with the coding sequences of a gene encoded by the counterstrand and is therefore not amenable for genetic manipulation. However, the E2 early promoter overlaps by only a few base pairs with sequences on the counterstrand which encode a 33 kD protein. Notably, an Spel restriction site (Ad5 position 27,082) is part ofthe stop codon for the above mentioned 33 kD protein and conveniently separates the major E2 early transcription initiation site and TATA box from the upstream E2F and ATF binding sites. Therefore, insertion of a heterologous TRE having Spel ends into the Spel site disrupts the endogenous E2 early promoter of Ad5 and allows TRE-regulated expression of E2 transcripts. An E3 region refers to the region ofthe adenoviral genome that encodes the E3 products. The E3 region has been described in various publications, including, for example, Wold et al. (1995) Curr. Topics Microbiol Immunol. 199:237-274. Generally, the E3 region is located between about 28583 and about 30470 ofthe adenoviral genome. An E3 region for use in the present invention may be from any adenoviras serotype. An E3 sequence is a polynucleotide sequence that contains a sequence from an E3 region. In some embodiments, the sequence encodes ADP. In other embodiments, the sequence encodes other than ADP and excludes a sequence encoding only ADP. As is well known in the art, the ADP coding region is located in the E3 region within the adenoviral genome from about 29468 bp to about 29773 bp; including the Y leader, the location of ADP is from about 28375 bp to about 29773 bp for Ad5. Other ADP regions for other serotypes are known in the art. An E3 sequence includes, but is not limited to, deletions; insertions; fusions; and substitutions. An E3 sequence may also comprise an E3 region or a portion of the E3 region. It is understood that, as an "E3 sequence" is not limited to an "E3 region", alternative references herein to an "E3 region" or "E3 sequence" do not indicate that these terms are interchangeable. Assays for determining a functional E3 sequence for purposes of this invention are described herein. The E4 gene has a number of transcription products and encodes two polypeptides (the products of open reading frames (ORFs) 3 and 6) which are responsible for stimulating the repUcation of viral genomic DNA and stimulating late gene expression, through interaction with heterodimers of cellular franscription factors E2F-1 and DP-1. The ORF 6 protein requires interaction with the EIB 55 kD protein for activity while the ORF 3 protein does not. In the absence of functional ORF 3- and ORF 6-encoded proteins, efficiency of plaque formation is less than 10 "6 that of wild type viras. To further increase cell-specificity of replication, it is possible to take advantage of the interaction between the E4 ORF 6 gene product and the EIB 55 kD protein. For example, if E4 ORFs 1-3 are deleted, viral DNA replication and late gene synthesis becomes dependent on E4 ORF6 protein. By generating such a deletion in a vector in which the EIB region is regulated by a cell-specific TRE, a viras is obtained in which both EIB and E4 functions are dependent on the cell-specific TRE which regulates EIB. Late genes relevant to the disclosed vectors are LI, L2 and L3, which encode proteins ofthe virion. All of these genes (typically coding for structural proteins) are probably required for adenoviral replication. All late genes are under the confrol ofthe major late promoter (MLP), which is located in Ad5 between nucleotides 5986 and 6048. In one embodiment, an adenoviras early gene is under franscriptional control of a cell specific, heterologous TRE. In additional embodiments, the early gene is selected from the group including EIA, EIB, E2, E3, E4. In another embodiment, an adenoviras late gene is under franscriptional control of a cell specific, heterologous TRE. In further embodiments, two or more early genes are under the confrol of heterologous TREs that function in the same target cell. The heterologous TREs can be the same or different, or one can be a variant ofthe other. In additional embodiments, two or more late genes are under the confrol of heterologous TREs that function in the same target cell. The heterologous TREs can be the same or different, or one can be a variant ofthe other. In yet another embodiment, one or more early gene(s) and one or more late gene(s) are under transcriptional confrol ofthe same or different heterologous TREs, wherein the TREs function in the same target cell. In some embodiments ofthe present invention, the adenoviras vector comprises the essential gene EIA and the El A promoter is deleted. In other embodiments, the adenovims vector comprises the essential gene EIA and the El A enhancer I is deleted. In yet other embodiments, the El A promoter is deleted and EIA enhancer I is deleted. In other embodiments, an internal ribosome entry site (IRES) is inserted upsfream of EIB (so that EIB is franslationally linked), and a target cell-specific TRE is operably linked to El A. In still other embodiments, an (IRES) is inserted upsfream of EIB (so that EIB is franslationally linked), and target cell-specific TRE is operably linked to El A, which may or may not maintain the EIA promoter and/or enhancer I (i.e., the EIA promoter and/or enhancer I may be, but not necessarily be, deleted). In yet other embodiments, the 19-kDa region of E 1 B is deleted. For adenovims vectors comprising a second gene under confrol of an IRES, it is preferred that the endogenous promoter of a gene under translational control of an IRES be deleted so that the endogenous promoter does not interfere with franscription ofthe second gene. It is preferred that the second gene be in frame with the IRES if the IRES contains an initiation codon. If an initiation codon, such as ATG, is present in the IRES, it is preferred that the initiation codon ofthe second gene is removed and that the IRES and second gene are in frame. Alternatively, if the IRES does not contain an initiation codon or if the initiation codon is removed from the IRES, the initiation codon ofthe second gene is used. Adenovirus death protein (ADP) gene and gene product In the construction of adenoviras vectors, the E3 region is often deleted to facilitate insertion of one or more TREs and/or transgenes. In some embodiments, however, the adenoviras death protein (ADP), encoded within the E3 region, is retained in an adenovirus vector. The ADP gene, under confrol ofthe major late promoter (MLP), appears to code for a protein (ADP) that is important in expediting host cell lysis. Tollefson et al. (1992) J Virol. 66:3633; and Tollefson et al {1996) J. Virol. 70:2296. Thus, inclusion of an ADP gene in a viral vector can render the vector more potent, making possible more effective treatment and/or a lower dosage requirement. An ADP coding sequence is obtained preferably from Ad2 (since this is the strain in which the ADP has been most fully characterized) using techniques known in the art, such as PCR. Preferably, the Y leader (which is an important sequence for correct expression of late genes) is also obtained and placed in operative linkage to the ADP coding sequence. The ADP coding sequence (with or without the Y leader) is then introduced into an adenoviral genome, for example, in the E3 region, where expression ofthe ADP coding sequence will be driven by the MLP. The ADP coding sequence can, of course, also be inserted in other locations ofthe adenoviras genome, such as the E4 region. Alternatively, the ADP coding sequence can be operably linked to a heterologous TRE, including, but not limited to, another viral TRE or a target cell-specific TRE (see infra). In another embodiment, the ADP gene is present in a viral genome such that it is franscribed as part of a multi-cisfronic mRNA in which its franslation is associated with an IRES. E3-containing target cell-specific adenoviral vectors In some embodiments, the adenovirus vectors contain an E3 region, or a portion of an E3 region. Inclusion ofthe E3 region of adenoviras can enhance cytotoxicity ofthe target cell-specific adenoviral vectors ofthe present invention. Adenoviral vectors containing an E3 region may maintain their high level of specificity and can be (a) significantly more cytotoxic; (b) produce higher viras yield including extracellular viras yield; (c) form larger plaques; (d) produce rapid cell death; and (e) kill tumors more efficiently in vivo than vectors lacking the E3 region. The adenoviral vectors of this invention may contain the E3 region or a portion ofthe E3 region. It is understood that, as inclusion of E3 confers observable and measurable functionality on the adenoviral vectors, for example, increased replication and production, functionally equivalent (in which functionality is essentially maintained, preserved, or even enhanced or diminished) variants of E3 may be constructed. For example, portions of E3 may be used. A portion may be, non-inclusively, either ofthe following: (a) deletion, preferably at the 3' end; (b) inclusion of one or more various open reading frames of E3. Five proteins which are encoded by the Ad-E3 region have been identified and characterized: (1) a 19-kDa glycoprotein (gpl9k) is one ofthe most abundant adenoviras early proteins, and is known to inhibit fransport ofthe major histocompatibility complex class I molecules to the cell surface, thus impairing both peptide recognition and clearance of Ad-infected cells by cytotoxic T lymphocytes (CTLs); (2) E3 14.7k protein and the E3 10.4k/14.5k complex of proteins inhibit the cytotoxic and inflammatory responses mediated by tumor necrosis factor (TNF); (3) E3 10.4k/14.5k protein complex down regulates the epidermal growth factor receptor, which may inhibit inflammation and activate quiescent infected cells for efficient viras replication; (4) E3 11.6k protein (adenoviral death protein, ADP) from adenoviras 2 and 5 appears to promote cell death and release of viras from infected cells. The functions of three E3-encoded proteins — 3.6k, 6.7k and 12.5k — are unknown. A ninth protein having a molecular weight of 7.5 kDa has been postulated to exist, but has not been detected in cells infected with wild-type adenoviras. Wold et al. (1995) Curr. Topics Microbiol. Immunol 199:237-274. The E3 region is schematically depicted in FIG. 6. These intact, portions, or variants of E3 may be readily constructed using standard knowledge and techniques in the art. Preferably, an intact E3 region is used. In the adenoviras vectors ofthe present invention, E3 may or may not be under franscriptional confrol of native adenoviral franscriptional control element(s). The E3 promoter is located within the coding sequence for virion protein VIII, an essential protein which is highly conserved among adenoviras serotypes. In some embodiments, E3 is under franscriptional confrol of a heterologous TRE, including, but not limited to, a target cell- specific TRE. Accordingly, in one embodiment, the invention provides an adenoviral vector, preferably replication competent, that comprises E3 region (or a portion of E3) under franscriptional confrol of a target cell-specific TRE. In other embodiments, the E3 region is under franscriptional confrol of a native adenoviral TRE, and the vector further comprises an adenoviral gene essential for replication under transcriptional confrol of a target cell-specific TRE. In other embodiments, the E3 region is under transcriptional confrol of a target cell-specific TRE, and the vector further comprises an adenoviral gene essential for replication under franscriptional confrol of a target cell-specific TRE. Transgenes under transcriptional control of a target cell-specific TSE Various other replication-competent adenovirus vectors can be made according to the present invention in which, in addition to having a single or multiple adenoviras gene(s) under confrol of a target cell-specific TRE, a fransgene(s) is/are also under confrol of a target cell-specific TRE and optionally under franslational control of an IRES. Transgenes include, but are not limited to, therapeutic transgenes and reporter genes. Reporter genes For example, a target cell-specific TRE can be introduced into an adenoviras vector immediately upsfream of and operably linked to an early gene such as EIA or EIB, and this construct may further comprise a second co-transcribed gene under translational control of an IRES. The second gene may be a reporter gene. The reporter gene can encode a reporter protein, including, but not limited to, chloramphenicol acetyl transferase (CAT), β-galactosidase (encoded by the lacZ gene), luciferase, alkaline phosphatase, a green fluorescent protein, and horse radish peroxidase. For detection of a putative cancer cell(s) in a biological sample, the biological sample may be treated with modified adenovirases in which a reporter gene (e.g., luciferase) is under control of a target cell- specific TRE. The target cell-specific TRE will be franscriptionally active in cells that allow the target cell-specific TRE to function, and luciferase will be produced. This production will allow detection of target cells, including cancer cells in, for example, a human host or a biological sample. Alternatively, an adenoviras can be constructed in which a gene encoding a product conditionally required for survival (e.g., an antibiotic resistance marker) is under franscriptional confrol of a target cell-specific TRE. When this adenoviras is introduced into a biological sample, the target cells will become antibiotic resistant. An antibiotic can then be introduced into the medium to kill the non-cancerous cells. Therapeutic transgenes Transgenes also include genes which may confer a therapeutic effect, such as enhancing cytotoxicity so as to eliminate unwanted target cells. In this way, various genetic capabilities may be introduced into target cells, particularly cancer cells. For example, in certain instances, it may be desirable to enhance the degree and/or rate of cytotoxic activity, due to, for example, the relatively refractory nature or particular aggressiveness ofthe cancerous target cell. This could be accomplished by coupling the target cell-specific cytotoxic activity with cell-specific expression of, for example, HSV-tk and/or cytosine deaminase (cd), which renders cells capable of metabolizing 5- fluorocytosine (5-FC) to the chemotherapeutic agent 5 -fluorouracil (5-FU). Using these types of transgenes may also confer a bystander effect. Other desirable transgenes that may be introduced via an adenoviras vector(s) include genes encoding cytotoxic proteins, such as the A chains of diphtheria toxin, ricin or abrin (Palmiter et al. (1987) Cell 50: 435; Maxwell et al. (1987) Mol. Cell. Biol. 7: 1576; Behringer et al. (1988) Genes Dev. 2: 453; Messing et al. (1992) Neuron 8: 507; Piatak et al. (1988) J Biol. Chem. 263: 4937; Lamb et al. (1985) Eur. J. Biochem. 148: 265; Frankel et al. (1989) Mol. Cell. Biol. 9: 415), genes encoding a factor capable of initiating apoptosis, sequences encoding antisense transcripts or ribozymes, which among other capabilities may be directed to mRNAs encoding proteins essential for proliferation, such as structural proteins, or franscription factors; viral or other pathogenic proteins, where the pathogen proliferates infracellularly; genes that encode an engineered cytoplasmic variant of a nuclease (e.g. RNase A) or protease (e.g. awsin, papain, proteinase K, carboxypeptidase, etc.), or encode the Fas gene, and the like. Other genes of interest include cytokines, antigens, fransmembrane proteins, and the like, such as IL-1, -2, -6, -12, GM-CSF, G-CSF, M-CSF, IFN-α, -β, -χ, TNF-α, -β, TGF-α, -β, NGF, and the like. The positive effector genes could be used in an earlier phase, followed by cytotoxic activity due to replication. Host cells The present invention also provides host cells comprising (i.e., transformed with) the adenoviral vectors described herein. Both prokaryotic and eukaryotic host cells can be used as long as sequences requisite for maintenance in that host, such as appropriate replication origin(s), are present. For convenience, selectable markers are also provided. Host systems are known in the art and need not be described in detail herein. Prokaryotic host cells include bacterial cells, for example, E. coli, B. subtilis, and mycobacteria. Among eukaryotic host cells are yeast, insect, avian, plant, C. elegans (or nematode) and mammaUan host cells. Examples of fungi (including yeast) host cells are S. cerevisiae, Kluyveromycέs lactis (K. lactis), species of Candida including C. albicans and C. glabrata, Aspergϊllus nidulans, Schizosaccharomyces pombe (S. pombe), Pichia pastor is, and Yαrrowiα lipolyticα. Examples of mammalian cells are cultured human target cells (HUC), KU-1, MYP3 (a non-tumorigenic rat target cell line), 804G (rat bladder carcinoma cell line), HCV-29, UM-UC-3, SW780, RT4, HL60, KG-1, and KG-1 A. COS cells, mouse L cells, LNCaP cells, Chinese hamster ovary (CHO) cells, human embryonic kidney (HEK) cells, and African green monkey cells. Xenopus lαevis oocytes, or other cells of amphibian origin, may also be used. Compositions and kits The present invention also includes compositions, including pharmaceutical compositions, containing the adenoviral vectors described herein. Such compositions are useful for administration in vivo, for example, when measuring the degree of transduction and/or effectiveness of cell killing in an individual. Compositions can comprise an adenoviral vector(s) ofthe invention and a suitable solvent, such as a physiologically acceptable buffer. These are well known in the art. In other embodiments, these compositions further comprise a pharmaceutically acceptable excipient. These compositions, which can comprise an effective amount of an adenoviral vector of this invention in a pharmaceutically acceptable excipient, are suitable for systemic or local administration to individuals in unit dosage forms, sterile parenteral solutions or suspensions, sterile non-parenteral solutions or oral solutions or suspensions, oil in water or water in oil emulsions and the like. Formulations for parenteral and nonparenteral drag delivery are known in the art and are set forth in Semington 's Pharmaceutical Sciences, 19th Edition, Mack Publishing (1995). Compositions also include lyophilized and/or reconstituted forms ofthe adenoviral vectors (including those packaged as a virus, such as adenoviras) ofthe invention. The present invention also encompasses kits containing an adenoviral vector(s) of this invention. These kits can be used for diagnostic and/or monitoring purposes, preferably monitoring. Procedures using these kits can be performed by clinical laboratories, experimental laboratories, medical practitioners, or private individuals. Kits embodied by this invention allow someone to detect the presence of bladder cancer cells in a suitable biological sample, such as biopsy specimens. The kits ofthe invention comprise an adenoviral vector described herein in suitable packaging. The kit may optionally provide additional components that are useful in the procedure, including, but not limited to, buffers, developing reagents, labels, reacting surfaces, means for detection, control samples, instructions, and interpretive information. Preparation ofthe adenovirus vectors ofthe invention The adenoviras vectors of this invention can be prepared using recombinant techniques that are standard in the art. Generally, a target cell-specific TRE is inserted 5' to the adenoviral gene of interest, preferably an adenoviral replication gene, more preferably one or more early replication genes (although late gene(s) can be used). A target cell-specific TRE can be prepared using oligonucleotide synthesis (if the sequence is known) or recombinant methods (such as PCR and/or resfriction enzymes). Convenient resfriction sites, either in the natural adeno-DNA sequence or introduced by methods such as PCR or site-directed mutagenesis, provide an insertion site for a target cell-specific TRE. Accordingly, convenient resfriction sites for annealing (i.e., inserting) a target cell-specific TRE can be engineered onto the 5' and 3' ends of a UP-TRE using standard recombinant methods, such as PCR. Polynucleotides used for making adenoviral vectors of this invention may be obtained using standard methods in the art, such as chemical synthesis, recombinant methods and/or obtained from biological sources. Adenoviral vectors containing all replication-essential elements, with the desired elements (e.g., EIA) under control of a target cell-specific TRE, are conveniently prepared by homologous recombination or in vitro ligation of two plasmids, one providing the left- hand portion of adenoviras and the other plasmid providing the right-hand region, one or more of which contains at least one adenoviras gene under confrol of a target cell-specific TRE. If homologous recombination is used, the two plasmids should share at least about 500 bp of sequence overlap. Each plasmid, as desired, may be independently manipulated, followed by cotransfection in a competent host, providing complementing genes as appropriate, or the appropriate franscription factors for initiation of franscription from a target cell-specific TRE for propagation ofthe adenoviras. Plasmids are generally infroduced into a suitable host cell such as 293 cells using appropriate means of transduction, such as cationic liposomes. Alternatively, in vitro ligation ofthe right and left-hand portions ofthe adenoviras genome can also be used to construct recombinant adenovims derivative containing all the replication-essential portions of adenoviras genome. Berkner et al. (1983) Nucleic AcidSesearch 11 : 6003-6020; Bridge et al. (1989) J Virol. 63: 631-638. For convenience, plasmids are available that provide the necessary portions of adenovirus. Plasmid pXC.l (McKinnon (1982) Gene 19:33-42) contains the wild-type left- hand end of Ad5. pBHGlO (Bett et al. (1994); Microbix Biosystems Inc., Toronto) provides the right-hand end of Ad5, with a deletion in E3. The deletion in E3 provides room in the virus to insert a 3 kb target cell-specific TRE without deleting the endogenous enhancer/promoter. The gene for E3 is located on the opposite sfrand from E4 (r-sfrand). pBHGl 1 provides an even larger E3 deletion (an additional 0.3 kb is deleted). Bett et al. (1994). Alternatively, the use of pBHGE3 (Microbix Biosystems, Inc:) provides the right hand end of Ad5, with a full-length of E3. For manipulation ofthe early genes, the franscription start site of Ad5 EIA is at 498 and the ATG start site ofthe EIA coding segment is at 560 in the virus genome. This region can be used for insertion of a target cell-specific TRE. A resfriction site may be infroduced by employing polymerase chain reaction (PCR), where the primer that is employed may be limited to the Ad5 genome, or may involve a portion ofthe plasmid carrying the Ad5 genomic DNA. For example, where pBR322 is used, the primers may use the EcoRI site in the pBR322 backbone and the Xbal site at nt 1339 of Ad5. By carrying out the PCR in two steps, where overlapping primers at the center ofthe region introduce a nucleotide sequence change resulting in a unique restriction site, one can provide for insertion of target cell-specific TRE at that site. A similar strategy may also be used for insertion of a target cell-specific TRE element to regulate EIB. The EIB promoter of Ad5 consists of a single high-affinity recognition site for Spl and a TATA box. This region extends from Ad5 nt 1636 to 1701. By insertion of a target cell-specific TRE in this region, one can provide for cell-specific franscription of the EIB gene. By employing the left-hand region modified with the cell- specific response element regulating El A, as the template for introducing a target cell- specific TRE to regulate EIB, the resulting adenoviras vector will be dependent upon the cell-specific franscription factors for expression of both EIA and EIB. In additional embodiments, the 19-kDa region of EIB is deleted. Similarly, a target cell-specific TRE can be inserted upsfream ofthe E2 gene to make its expression cell-specific. The E2 early promoter, mapping in Ad5 from 27050- 27150, consists of a major and a minor franscription initiation site, the latter accounting for about 5% ofthe E2 transcripts, two non-canonical TATA boxes, two E2F transcription factor binding sites and an ATF transcription factor binding site (for a detailed review of the E2 promoter architecture see Swaminathan et al., Cwrr. Topics in Micro, and Immunol. (1995) 199(part 3):177-194. The E2 late promoter overlaps with the coding sequences of a gene encoded by the counterstrand and is therefore not amenable for genetic manipulation. However, the E2 early promoter overlaps only for a few base pairs with sequences coding for a 33 kD protein on the counterstrand. Notably, the Spel restriction site (Ad5 position 27082) is part ofthe stop codon for the above mentioned 33 kD protein and conveniently separates the major E2 early franscription initiation site and TATA-binding protein site from the upsfream franscription factor binding sites E2F and ATF. Therefore, insertion of a target cell-specific TRE having Spel ends into the Spel site in the 1 -sfrand would disrupt the endogenous E2 early promoter of Ad5 and should allow target cell-restricted expression of E2 transcripts. For E4, one must use the right hand portion ofthe adenoviras genome. The E4 transcription start site is predominantly at about nt 35605, the TATA box at about nt 35631 and the first AUG/CUG of ORF I is at about nt 35532. Virtanen et al. (1984) J Virol. 51 : 822-831. Using any ofthe above strategies for the other genes, a UP-TRE may be infroduced upstream from the franscription start site. For the construction of full-length adenoviras with a target cell-specific TRE inserted in the E4 region, the co-transfection and homologous recombination are performed in W162 cells (Weinberg et al. (1983) Proc. Natl. Acad. Sci. 80:5383-5386) which provide E4 proteins in trans to complement defects in synthesis of these proteins. Adenoviral constructs containing an E3 region can be generated wherein homologous recombination between an E3 -containing adenoviral plasmid, for example, BHGE3 (Microbix Biosystems Inc., Toronto) and a non-E3 -containing adenoviral plasmid, is carried out. Alternatively, an adenoviral vector comprising an E3 region can be introduced into cells, for example 293 cells, along with an adenoviral construct or an adenoviral plasmid construct, where they can undergo homologous recombination to yield adenoviras containing an E3 region. In this case, the E3 -containing adenoviral vector and the adenoviral construct or plasmid construct contain complementary regions of adenoviras, for example, one contains the left-hand and the other contains the right-hand region, with sufficient sequence overlap as to allow homologous recombination. Alternatively, an E3 -containing adenoviral vector ofthe invention can be constructed using other conventional methods including standard recombinant methods (e.g., using restriction nucleases and/or PCR), chemical synthesis, or a combination of any of these. Further, deletions of portions ofthe E3 region can be created using standard techniques of molecular biology. Insertion of an IRES into a vector is accomplished by methods and techniques that are known in the art and described herein supra, including but not limited to, resfriction enzyme digestion, ligation, and PCR. A DNA copy of an IRES can be obtained by chemical synthesis, or by making a cDNA copy of, for example, a picornaviras IRES. See, for example, Duke et al. (1995) J. Vvirol. 66(3):1602-9) for a description ofthe EMCV IRES and Huez et al. (1998), Mol. Cell. Biol. 18(11):6178-90) for a description ofthe VEGF IRES. The internal franslation initiation sequence is inserted into a vector genome at a site such that it lies upsfream of a 5 '-distal coding region in a multicistronic mRNA. For example, in a preferred embodiment of an adenoviras vector in which production of a bicisfronic El A-EIB mRNA is under the control of a target cell-specific TRE, the EIB promoter is deleted or inactivated, and an IRES sequence is placed between EIA and EIB. IRES sequences of cardiovirases and certain aphthoviruses contain an AUG codon at the 3' end ofthe IRES that serves as both a ribosome entry site and as a franslation initiation site. Accordingly, this type of IRES is infroduced into a vector so as to replace the translation initiation codon ofthe protein whose franslation it regulates. However, in an IRES ofthe entero/rhinoviras class, the AUG at the 3' end ofthe IRES is used for ribosome entry only, and franslation is initiated at the next downstream AUG codon. Accordingly, if an entero/rhinoviras IRES is used in a vector for translational regulation of a downstream coding region, the AUG (or other franslation initiation codon) ofthe downstream gene is retained in the vector construct. Methods of packaging polynucleotides into adenoviras particles are known in the art and are also described in co-owned PCT PCT/US98/04080. Delivery of Adenovirus vectors The adenoviral vectors can be used in a variety of forms, including, but not limited to, naked polynucleotide (usually DNA) constracts. Adenoviral vectors can, alternatively, comprise polynucleotide constracts that are complexed with agents to facilitate entry into cells, such as cationic liposomes or other cationic compounds such as polylysine; packaged into infectious adenovirus particles (which may render the adenoviral vector(s) more immunogenic); packaged into other particulate viral forms such as HSV or AAV; complexed with agents (such as PEG) to enhance or dampen an immune response; complexed with agents that facilitate in vivo transfection, such as DOTMA™, DOTAP™, and polyamines. If an adenoviral vector comprising an adenoviras polynucleotide is packaged into a whole adenoviras (including the capsid), the adenoviras itself may also be selected to further enhance targeting. For example, adenoviras fibers mediate primary contact with cellular receptor(s) aiding in fropism. See, e.g., Amberg et al. (1997) Virol. 227:239-244. If a particular subgenus of an adenoviras serotype displayed fropism for a target cell type and/or reduced affinity for non-target cell types, such subgenus(or subgenera) could be used to further increase cell-specificity of cytotoxicity and/or cytolysis. The adenoviral vectors may be delivered to the target cell in a variety of ways, including, but not Umited to, liposomes, general transfection methods that are well known in the art, such as calcium phosphate precipitation, electroporation, direct injection, and intravenous infusion. The means of delivery will depend in large part on the particular adenoviral vector (including its form) as well as the type and location ofthe target cells (i.e., whether the cells are in vitro or in vivo). If used in packaged adenovirases, adenoviras vectors may be administered in an appropriate physiologically acceptable carrier at a dose of about 10 4 to about 10 14 . The multiplicity of infection will generally be in the range of about 0.001 to 100. If administered as a polynucleotide construct (i.e., not packaged as a viras) about 0.01 μg to about 1000 μg of an adenoviral vector can be administered. The adenoviral vector(s) may be administered one or more times, depending upon the intended use and the immune response potential ofthe host or may be administered as multiple, simultaneous injections. If an immune response is undesirable, the immune response may be diminished by employing a variety of immunosuppressants, so as to permit repetitive administration, without a strong immune response. If packaged as another viral form, such as HSV, an amount to be administered is based on standard knowledge about that particular viras (which is readily obtainable from, for example, published literature) and can be determined empirically. Methods using the adenovirus vectors ofthe invention The subject vectors can be used for a wide variety of purposes, which will vary with the desired or intended result. Accordingly, the present invention includes methods using the adenoviral vectors described above. In one embodiment, methods are provided for conferring selective cytotoxicity in cells that allow a target cell-specific TRE to function, preferably target cells, comprising contacting such cells with an adenoviras vector described herein. Cytotoxicity can be measured using standard assays in the art, such as dye exclusion, 3 H-thymidine incorporation, and/or lysis. In another embodiment, methods are provided for propagating an adenoviras specific for cells which allow a target cell-specific TRE to function, preferably target cells, preferably cancer cells. These methods entail combining an adenoviras vector with the cells, whereby said adenoviras is propagated. Another embodiment provides methods for killing cells that allow a target cell- specific TRE to function in a mixture of cells, comprising combining the mixture of cells with an adenoviras vector ofthe present invention. The mixture of cells is generally a mixture of normal cells and cancerous cells that allow a target cell-specific TRE to function, and can be an in vivo mixture or in vitro mixture. The invention also includes methods for detecting cells which allow a target cell- specific TRE to function, such as cancer cells, in a biological sample. These methods are particularly useful for monitoring the clinical and/or physiological condition of an individual (i.e., mammal), whether in an experimental or clinical setting. In one method, cells of a biological sample are contacted with an adenoviras vector, and replication ofthe adenoviral vector is detected. Alternatively, the sample can be contacted with an adenoviras in which a reporter gene is under control of a target cell-specific TRE. When such an adenovims is introduced into a biological sample, expression ofthe reporter gene indicates the presence of cells that allow a target cell-specific TRE to function. Alternatively, an adenoviras can be constructed in which a gene conditionally required for cell survival is placed under confrol of a target cell-specific TRE. This gene may encode, for example, antibiotic resistance. Later the biological sample is freated with an antibiotic. The presence of surviving cells expressing antibiotic resistance indicates the presence of cells capable of target cell-specific TRE function. A suitable biological sample is one in which cells that allow a target cell-specific TRE to function, such as cancer cells, may be or are suspected to be present. Generally, in mammals, a suitable clinical sample is one in which cancerous cells that allow a target cell-specific TRE to function, such as carcinoma cells, are suspected to be present. Such cells can be obtained, for example, by needle biopsy or other surgical procedure. Cells to be contacted may be freated to promote assay conditions, such as selective enrichment, and/or solubilization. In these methods, cells that allow a target cell-specific TRE to function can be detected using in vitro assays that detect adenoviral proliferation, which are standard in the art. Examples of such standard assays include, but are not limited to, burst assays (which measure virus yield) and plaque assays (which measure infectious particles per ceil). Propagation can also be detected by measuring specific adenoviral DNA replication, which are also standard assays. The invention also provides methods of modifying the genotype of a target cell, comprising contacting the target cell with an adenoviras vector described herein, wherein the adenoviral vector enters the cell. The invention further provides methods of suppressing tumor cell growth, preferably a tumor cell that allows a target cell-specific TRE to function, comprising contacting a tumor cell with an adenoviral vector ofthe invention such that the adenoviral vector enters the tumor cell and exhibits selective cytotoxicity for the tumor cell. For these methods, the adenoviral vector may or may not be used in conjunction with other freatment modalities for tumor suppression, such as chemotherapeutic agents (such as those listed below), radiation and/or antibodies. The invention also provides methods of lowering the levels of a tumor cell marker in an individual, comprising administering to the individual an adenoviral vector ofthe present invention, wherein the adenoviral vector is selectively cytotoxic toward cells that allow a target cell-specific TRE to function. Tumor cell markers include, but are not limited to, CK-20. Methods of measuring the levels of a tumor cell marker are known to those of ordinary skill in the art and include, but are not limited to, immunological assays, such as enzyme-linked immunosorbent assay (ELISA), using antibodies specific for the tumor cell marker. In general, a biological sample is obtained from the individual to be tested, and a suitable assay, such as an ELISA, is performed on the biological sample. For these methods, the adenoviral vector may or may not be used in conjunction with other freatment modalities for tumor suppression, such as chemotherapeutic agents (such as those listed below), radiation and/or antibodies. The invention also provides methods of freatment, in which an effective amount of an adenoviral vector(s) described herein is administered to an individual. Treatment using an adenoviral vector(s) is indicated in individuals with cancer as described above. Also indicated are individuals who are considered to be at risk for developing cancer (including single cells), such as those who have had disease which has been resected and those who have had a family history of cancer. Determination of suitability of administering adenoviral vector(s) ofthe invention will depend, inter alia, on assessable clinical parameters such as serological indications and histological examination of tissue biopsies. Generally, a pharmaceutical composition comprising an adenoviral vector(s) in a pharmaceutically acceptable excipient is administered. Pharmaceutical compositions are described above. For these methods, the adenoviral vector may or may not be used in conjunction with other freatment modalities for tumor suppression, such as chemotherapeutic agents (such as those listed below), radiation and/or antibodies. The amount of adenoviral vector(s) to be administered will depend on several factors, such as route of administration, the condition ofthe individual, the degree of aggressiveness ofthe disease, the particular target cell-specific TRE employed, and the particular vector construct (i.e., which adenovirus gene(s) is under target cell-specific TRE confrol) as well as whether the adenoviral vector is used in conjunction with other freatment modalities. If administered as a packaged adenoviras, from about 10 4 to about 10 14 , preferably from about 10 4 to about 10 12 , more preferably from about 10 4 to about 10 10 . If administered as a polynucleotide construct (i.e., not packaged as a viras), about 0.01 μg to about 100 μg can be administered, preferably 0.1 μg to about 500 μg, more preferably about 0.5 μg to about 200 μg. More than one adenoviral vector can be administered, either simultaneously or sequentially. Administrations are typically given periodically, while monitoring any response. Administration can be given, for example, infratumorally, intravenously or infraperitoneally. The adenoviral vectors ofthe invention can be used alone or in conjunction with other active agents, such as chemotherapeutics, that promote the desired objective. Examples of chemotherapeutics which are suitable for suppressing bladder tumor growth are BGC (bacillus Calmett-Guerin); mitomycin-C; cisplatin; thiotepa; doxombicin; methotrexate; paclitaxel (TAXOL™); ifosfamide; gallium nitrate; gemcitabine; carboplatin; cyclosphasphamid; vinblastine; vincristin; fluorouracil; etoposide; bleomycin. Examples of combination therapies include (CISCA (cyclophosphamide, doxorubicin, and cisplatin); CMV (cisplatin, methotrexate, vinblastine); MVMJ (methodfrextate, vinblastine, mitoxantrone, carboplain); CAP (cyclophosphamide, doxombicin, cisplatin); MVAC (methotrexate, vinblastine, doxorubicin, cisplatin). Radiation may also be combined with chemotherapeutic agent(s), for example, radiation with cisplatin. Administration ofthe chemotherapeutic agents is generally infravesical (directly into the bladder) or intravenous. The following examples are provided to illustrate but not limit the invention. EXAMPLES Example 1: Construction of a replication-competent adenovirus vector comprising an AFP-TRE and an EMCV IRES The encephalomyocarditis viras (ECMV) IRES as depicted in Table 1 was introduced between the EIA and EIB regions of a replication-competent adenoviras vector specific for cells expressing AFP as follows. Table 1 shows the 519 base pair IRES segment which was PCR amplified from Novagen's pCITE vector by primers A/B as listed in Table 4. A 98 base pair deletion in the EIA promoter region was created in PXC.l, a plasmid which contains the left-most 16 mu of Ad5. Plasmid pXC.l (McKinnon (1982) Gene 19:33-42) contains the wild-type left-hand end of Ad5, from Adenovirus 5 nt 22 to 5790 including the inverted terminal repeat, the packaging sequence, and the El a and Elb genes in vector pBR322. pBHGlO (Bett. et al. (1994) Proc. Natl. Acad. Sci. USA 91:8802- 8806; Microbix Biosystems Inc., Toronto) provides the right-hand end of Ad5, with a deletion in E3. The resultant plasmid, CP306 (PCT/US98/16312), was used as the backbone in overlap PCR to generate CP624. To place a Sail site between El a and Elb, primers C/D, E/F (Table 4) were used to amplify CP306, plasmid derived from pXC.l and lacking the El a promoter. After first round PCR using CP306 as template and primers C/D, E/F, the resultant two DNA fragments were mixed together for another round of overlapping PCR with primers C/F. The overlap PCR product was cloned by blunt end ligation to vector. The resultant plasmid, CP624 (Table 5), contains 100 bp deletion in Ela/Elb intergenic region and introduces Sail site into the junction. On this plasmid, the endogenous El a promoter is deleted, and the El a polyadenylation signal and the Elb promoter are replaced by the Sail site. Next, the Sail fragment of CP625 was cloned into the Sallsite in CP624 to generate CP627 (Table 5). CP627 has an EMCV IRES connecting adenovims essential genes Ela and Elb. In CP627, a series of different tumor-specific promoters can be placed at the PinAλ site in front of Ela to achieve transcriptional control on El expression. Table 4 Primer Sequence Note A. 5'-GACGTCGACTAATTCCGGTTATTTTCCA For PCR EMCV IRES, GTCGAC is a Sail site. B. 5'-GACGTCGACATCGTGTTTTTCAAAGGAA For PCR EMCV IRES, GTCGAC is a Sail site. C. 5'-CCTGAGACGCCCGACATCACCTGTG Ad5 sequence to 1314 to 1338. D. 5'-GTCGACCATTCAGCAAACAAAGGCGTTAAC Antisense of Ad5 sequence 1572 to 1586. GTCGAC is a Sail site. Underline region overlaps with E. E. 5'-TGCTGAATGGTCGACATGGAGGCTTGGGAG Ad5 sequence 1714 to 1728. GTCGAC is a Sail site. Underline region overlaps with D. F. 5'-CACAAACCGCTCTCCACAGATGCATG Antisense of Ad5 sequence 2070 to 2094. For generating a liver cancer-specific vims, an about 0.8kb AFP promoter fragment as shown in Table 3 was placed into the E Al site of CP627 thereby yielding plasmid CP686. Full-length viral genomes were obtained by recombination between CP686 and a plasmid containing a right arm of an adenovims genome. The right arms used in vims recombination were pBHGΕ3 (Microbix Biosystems Inc.), containing an intact E3 region, and pBHGl 1 or pBHGlO (Bett et al. (1994) containing a deletion in the E3 region. The vims obtained by recombination of CP686 with a right arm containing an intact E3 region was named CV890. The vims obtained by recombination of CP686 with a right arm containing a deleted E3 region (pBHG 10) was named CV840. The structure of all viral genomes was confirmed by conducting PCR amplifications that were diagnostic for the corresponding specific regions. Therefore, adenovims vector designated CV890 comprises 0.8 kb AFP promoter, EIA, a deletion ofthe EIA promoter, EMCV IRES, EIB a deletion ofthe EIB promoter and an intact E3 region. Adenovims vector CV840 comprises AFP promoter, EIA, a deletion ofthe EIA promoter, EMCV IRES, EIB, a deletion ofthe EIB promoter and a deleted E3 region. Table 5 Plasmid Brief description designation CP306 An El A promoter deleted plasmid derived from pXC.1 CP624 Overlap PCR product from CP306 to generate 100 bp deletion and introduce a Sail site at EIA and EIB junction; EIA and EIB promoter deleted in E1A/E1B intergenic region. CP625 EMCV IRES element ligated to PCR-blunt vector (Invitrogen pCR® blunt vector). CP627 IRES element derived from CP625 by Sa/1 digestion and ligated to CP624 Sail site placing IRES upstream from EIB. CP628 Probasin promoter derived from CP251 by PinAl digestion and cloned into PinAl site on CP627. CP629 HCMV IE promoter amplified from pCMV beta (Clontech) with PinAl at 5 ' and 3 ' ends ligated into CP627 PinAl site. CP630 A 163 bp long VEGF IRES fragment (Table 1) cloned into the Sa/1 site on CP628. CP686 AFP promoter from CP219 digested with PinAl and cloned into PinAl site on CP627. Example 2: Construction of a replication-competent adenovirus vector with a probasin TRE and an EMCV IRES The probasin promoter as shown in Table 3 was inserted at the PinAl site of plasmid CP627 (see Example 1) to generate CP628, which contains a probasin promoter upstream of El A and an EMCV IRES between EIA and EIB. Full-length viral genomes were obtained by recombination between CP628 and a plasmid containing a right arm of an adenovims genome. The right arms used in vims recombination were pBHGE3, containing an intact E3 region, and pBHGl 1 or pBHGlO containing a deletion in the E3 region. The stmcture of all viral genomes was confirmed by conducting PCR amplifications that were diagnostic for the corresponding specific regions. Therefore, adenovims designated CV 834 comprises probasin promoter, EIA, a deletion ofthe EIA promoter, EMCV IRES, EIB, a deletion ofthe EIB endogenous promoter and a deleted E3 region. Example 3: Construction of a replication-competent adenovirus vector with a hCMV-TRE and an EMCV IRES The hCMV immediate early gene (IE) promoter from plasmid CP629, originally derived from pCMVBeta (Clonetech, Palo Alto) was inserted at the PinAl site of plasmid CP627 (see Example 1) to generate CP629, containing a CMV IE promoter upstream of EIA and an IRES between EIA and EIB. Full-length viral genomes were obtained by recombination between CP629 and a plasmid containing a right arm of an adenovims genome. The right arms used in viras recombination were pBHGE3, containing an intact E3 region, and pBHGl 1 or pBHGlO containing a deletion in the E3 region. The structure of all viral genomes was confirmed by conducting PCR amplifications that were diagnostic for the corresponding specific regions. Therefore, adenoviras vector designated CV835 comprises hCMV-IE promoter, EIA, a deletion ofthe EIA promoter, EMCV IRES, EIB a deletion in the EIB endogenous promoter and a deleted E3 region. CV835 lacks the hCMV enhancer and is therefore not tissue specific. By adding the hCMV IE enhancer sequence to CV835, the vector is made tissue specific. Example 4: Replication of IRES-containing adenovirus vectors with different TREs controlling El expression The viral replication of adenoviras vectors comprising the probasin promoter (CV836 and CV834) generally considered a weak promoter, and the human cytomegalovirus immediate early gene (HCMV-IE) promoter (CV837 and CV835), generally considered a strong promoter, were characterized in the vims yield assay. Probasin promoter containing adenoviras vectors (see PCT/US98/04132), CV836 and CV834, and HCMV-IE promoter containing adenoviras vectors, CV837 and CV835, were tested against a panel of cell lines for viral replication (indicative of lethality) and specificity. Cell lines 293 (the producer line), LNCap and HepG2 were plated at 0.5 x 10 per well in 6 well tissue culture plates, incubated for 24 hours at 37° C, then infected with CV836, CV834 or CV837 and CV835 at a multiplicity of infection (MOI) of 2 plaque forming units per cell (PFU/cell) for 4 hours at 37° C. At the end ofthe infection period, the medium was replaced and the cells were incubated at 37° C for a further 72 hours before harvesting for a viral yield assay as described in Yu et al. (1999) Cancer Ses. 59:1498-1504. The results are shown in Fig. 3. The data demonstrate that the presence of an IRES element in the intergenic region between EIA and EIB does not significantly affect viral replication, as compared to confrol viruses lacking an IRES, such as a wild-type AD5 with a deletion in the E3 region. In CV834, the loss of tissue cytotoxicity could be caused by the weakness ofthe probasin promoter in the viras structure. Example 5: Comparison of dual TRE vectors with single TRE/IRES- containing vectors Two liver cancer-specific adenoviras vectors, CV790 and CV733 (also designated CN790 and CN733, respectively), were generated and characterized. See PCT/US98/04084. These vimses contain two AFP TREs, one upsfream of El A and one upstream of EIB. They differ in that CV790 contains an intact E3 region, while the E3 region is deleted in CV733. Replication of these two viruses was compared with that ofthe newly generated IRES-containing viruses, CV890 and CV840 (see Example 1). Viras replication was compared, in different cell types, using a viras yield assay as described in Example 4. Cells were infected with each type of viras and, 72 hrs after infection, viras yield was determined by a plaque assay. Figs. 4A and 4B show viral yield for different vimses in different cell types. The results indicate that vectors containing an IRES between EIA and EIB (CV890 and CV840), in which EIB translation is regulated by the IRES, replicate to similar extents as normal adenovims and vimses with dual AFP TREs, in AFP-producing cells such as 293 cells and hepatoma cells. In SK-Hep-1 (liver cells), PA-1 (ovarian carcinoma) and LNCaP cells (prostate cells) the IRES-containing vimses do not replicate as well as dual TRE or wild-type adenovirases, indicating that the IRES-containing viruses have higher specificity for hepatoma cells. Based on these results, it is concluded that IRES-containing vectors have unaltered replication levels, but are more stable and have better target cell specificity, compared to dual-TRE vectors. Example 6: Uroplakin adenoviral constructs containing an EMCV IRES A number of E3 -containing viral constracts were prepared which contained uroplakin II sequences (mouse and/or human) as well as an EMCV internal ribosome entry site (IRES). The viral constracts are summarized in Table 6. All of these vectors lacked an EIA promoter and retained the El A enhancer. The 519 base pair EMCV IRES segment was PCR amplified from Novagen's pCITE vector by primers A/B: primer A: 5'-GACGTCGACTAATTCCGGTTATTTTCCA primer B 5'-GACGTCGACATCGTGTTTTTCAAAGGAA {GTCGAC is a Sail site). The EMCV IRES element was ligated to PCR blunt vector (Invitrogen pCR® blunt vector). CP1066 The 1.9kb-(-l 885 to +1) fragment of mouse UPII from CP620 was digested with Afllll (blunted) and Hindlll and inserted into pGL3-Basic from CP620 which had been digested with Xhol (blunted) and Hindlll to generate CP1066. CP1086 The 1.9kb mouse UPII insert was digested with PinAl and ligated with CP269 (CMV driving EIA and IRES driving EIB with the deletions of El A/El B endogenous promoter) which was similarly cut by PinAl. CP1087 The lkb (-1128 to +1) human UPII was digested with PinAl from CP665 and inserted into CP629 which had been cut by PinAl and purified (to elute CMV). CP1088 The 2.2kb (-2225 to +1) human UPII was amplified from CP657 with primer 127.2.1 (5'-AGGACCGGTCACTATAGGGCACGCGTGGT-3') PLUS 127.2.2 (5'- AGGACCGGTGGGATGCTGGGCTGGGAGGTGG-3') and digested with PinAl and ligated with CP629 cut with PinAl. CP627 is an Ad5 plasmid with an internal ribosome entry site (IRES) from encephelomycarditis viras (EMCV) at the junction of El A and EIB. First, CP306 (Yu et al., 1999) was amplified with primer pairs 96.74.3/96.74.6 and 96.74.4/96.74.5. The two PCR products were mixed and amplified with primer pairs 96.74.3 and 96.74.5. The resultant PCR product contains a lOObp deletion in El A-EIB intergenic region and a new Sail site at the junction. EMCV IRES fragment was amplified from pCITE-3a(+) (Novagen) using primers 96.74.1 and 96.74.2. The Sail fragment containing IRES was placed into Sail site to generate CP627 with the bicisfronic El A-IRES-EIB cassette. CP629 is a plasmid with CMV promoter amplified from pCMVbeta (Clontech) with primer 99.120.1 and 99.120.2 and cloned into PinAI site of CP627. CP657 is a plasmid with 2.2kb 5' flanking region of human UP II gene in pGL3- Basic (Promega). The 2.2kb hUPII was amplified by PCR from Genome Walker product with primer 100.113.1 and 100.113.2 and TA-cloned into pGEM-T to generate CP655. The 2.2kb insert digested from SacII (blunt-ended) and Kpnl was cloned into pGL3-Basic at Hin TII (blunted) and Kpnl to create CP657. CP1089 The lkb (-965 to +1) mouse UPII was digested by PinAI from CP263 and inserted into CN422 (PSE driving EIA and GKE driving EIB with the deletions of El A/E1B endogenous promoter) cut by PinAI and purified and further digested with Eagl and ligated with lkb (-1128 to +1) human UPII cut from CP669 with Eagl. CP1129 The 1.8kb hUPII fragment with PinAI site was amplified from CP657 with primer 127.50.1 and 127.2.2 and cloned into PinAI site of CP629. CP1131 CP686 was constructed by replacing the CMV promoter in CP629 with an AFP fragment from CP219. A 1.4kb DNA fragment was released from CP686 by digesting it with BssHII, filling with Klenow, then digesting with Bglll. This DNA fragment was then cloned into a similarly cut CP686 to generate CP1199. In CP1199, most ofthe EIB 19-KDa region was deleted. The 1.8kb hUPII fragment with PinAI site was amplified from CP657 by PCR with primer 127.50.1 and 127.2.2 and inserted into similarly digested CP1199 to create CP1131. The plasmids above were all co-fransfected with pBHGE3 to generate CV874 (from CP1086), CV875 (from CP1087), CV876 (from 1088) and CV877 (from CP1089), CV882 (from CP1129) and CV884 (from CP1131). CP1088, CP1129 and CP1131 were cofransfected with pBHGE3 for construction of CV876, CV892 and CV884, respectively by lipofectAMTNE (Gibco/BRL) for 11-14 days. pBHGE3 was purchased from Microbix, Inc., and was described previously. The cells were lysed by three freeze-thaw cycles and plaqued on 293 cells for a week. The single plaques were picked and amplified by infection in 293 cells for 3-5 days. The viral DNAs were isolated from the lysates and the constracts were confirmed by PCR with primer 31.166.1/ 51.176 for CV876 and primer 127.50.1/51.176 for CV882 and CV884 at El region and primer 32.32.1/2 for all three vimses at E3 region. TABLE 6 Name Vector Ad 5 Vector EIA TRE EIB TRE E3 CV874 CP1086 pBHGE3 1.9 kb mUPII IRES intact CV875 CP1087 pBHGE3 l.O kb hUPII IRES intact CV876 CP1088 pBHGE3 2.2 kb hUPII IRES intact CV877 CP1089 pBHGE3 l.O kb mUPII l.O kb hUPII (EIB intact promoter deleted) CV882 CP1129 pBHGE3 l.δ kb hUPII IRES intact CV884 CP1131 pBHGE3 1.8 kb hUPii IRES (EIB 19-kDa intact deleted) Viruses are tested and characterized as described above. Primer sequences: 96.74.1 GACGTCGACATCGTGTTTTTCAAAGGAA 96.74.2 GACGTCGACTAATTCCGGTTATTTTCCA 96.74.3 CCTGAGACGCCCGACATCACCTGTG 96.74.4 TGCTGAATGGTCGACATGGAGGCTTGGGAG 96.74.5 CACAACCGCTCTCCACAGATGCATG 96.74.6 GTCGACCATTCAGCAAACAAAGGCGTTAAC 100.113.1 AGGGGTACCCACTATAGGGCACGCGTGGT 100.113.2 ACCCAAGCTTGGGATGCTGGGCTGGGAGGTGG 127.2.2 AGGACCGGTGGGATGCTGGGCTGGGAGGTGG 127.50.1 AGGACCGGTCAGGCTTCACCCCAGACCCAC 31.166.1 TGCGCCGGTGTACACAGGAAGTGA 32.32.1 GAGTTTGTGCCATCGGTCTAC 32.32.2 AATCAATCCTTAGTCCTCCTG 51.176 GCAGAAAAATCTTCCAAACACTCCC 99.120.1 ACGTACACCGGTCGTTACATAACTTAC 99.120.2 CTAGCAACCGGTCGGTTCACTAAACG Example 7: Construction of a replication-competent adenovirus vector with a tyrosinase TRE and EMCV IRES CP621 is a plasmid containing a human tyrosinase enhancer and promoter elements in a PinAl fragment. This fragment is ligated to the PinAl site on CP627 to generate CP1078. CP1078 is combined with pBHGE3 to generate a new melanoma specific viras, CV859. Table 3 depicts the polynucleotide sequence ofthe PinAl fragment which contains a tyrosinase promoter and enhancer. Example 8: Construction of a replication-competent adenovirus vector with a probasin-TRE and a VEGF IRES Using a strategy similar to that described in Example 1, the IRES fragment from the mouse vascular endothelial growth factor (VEGF) gene is amplified and cloned into CP628 at the Sail site. Table 1 depicts the IRES fragment obtainable from vascular endothelial growth factor (VEGF) mRNA. In order to clone this fragment into the Ela/Elb intergenic region, two pieces of long oligonucleotide are synthesized. The sense oligonucleotide is shown in the Table, whereas the second piece is the corresponding antisense one. After annealing the two together to create a duplex, the duplex is subjected to Sail digestion and the resulting fragment is cloned into the Sail site on CP628. The resulting plasmid, CP630, has a probasin promoter in front of Ela and an VEGF IRES element in front of Elb. This plasmid is used to constract a prostate cancer-specific viras comprising the VEGF IRES element. Example 9: Construction of a replication-competent adenovirus vector with an AFP-TRE and a VEGF IRES Using a strategy similar to Example 1, a PinAI fragment which contains AFP TRE can be obtained. This AFP TRE is cloned into the PinAl site in front of El A on CP628 yielding plasmid CP1077. This plasmid has the AFP TRE for El franscriptional confrol and the VEGF IRES element before Elb. CP1077 can be recombined with pBHGE3 to generate a liver-specific adenoviras, designated as CV858. Example 10: Construction of a replication-competent adenovirus vector with a hKLK2-TRE and a EMCV IRES Using a strategy similar to Example 1, the TRE fragment from human glandular kallikrein II as shown in Table 3 was cloned into the PinAI site in CP627. The resultant plasmid, CP 1079, is cofransfected with pBHGE3 to create CV860. Example 11: Treatment of Hep3B Tumor Xenografts with Replication- Competent Hepatoma Specific CV790 and Doxorubicin and Hepatoma Specific CV890 and Doxorubicin CV790 is an AFP producing hepatocellular carcinoma specific adenoviras, with EIA and EIB under the confrol of an identical AFP promoter and enhancer (822 base pair promoter shown in Table 3) with an E3 region. The CV890 adenoviras constract is also a hepatoma or liver-specific adenoviral mutant with the EIA and EIB genes under transcriptional confrol of 822bp AFP promoter (827 bp including nucleotides for restriction site), wherein EIB is under translational confrol of EMCV IRES and having an intact E3 region. The structure of CV890 therefore reads as AFP/El A, IRES/EIB, E2, E3, E4. In vivo studies ofthe efficacy of combinations of CV790 and doxorubicin and CV890 and doxorubicin were performed according to the protocols described in detail in Example 4, with minor alterations which are described below. Xenografts in the study of CV790 and CV890 combined with chemotherapeutic agents utilized liver carcinoma Hep3B cells. Viras, CV790 or CV890, was administered by a single intravenous injection of 1 x 10 11 particles through the tail veins ofthe nude mice. One day after viras delivery, a single dose of doxombicin was given to each animal by i.p. injection. The doxombicin dose was 10 mg/kg for both doxombicin alone and doxorubicin combined with virus treatments. Tumor volume was measured once a week for six weeks. Tumors were measured weekly in two dimensions by external caliper and volume was estimated by the formula [length (mm) x width (mm) 2 ]/2. Figure 8 depicts the anti-tumor activity of CV890 containing an IRES as compared to CV 790 containing dual TREs. As Figure 8 demonstrates, relative tumor volume was less with adminisfration of CV890 than adminisfration of CV790. Furthermore, both CV790/doxorabicin and CV890/doxorabicin freatment ofthe hepatoma showed synergistic results. Four days after freatment with either CV790/doxorabicin or CV890/doxorubicin the relative tumor volume was less than 10%. Unlike mice treated with either viras alone or doxorubicin alone, after day 4, the relative tumor volume did not increase for either the either CV790/doxorabicin or CV890/doxorabicin treated mice. At day 6 in the confrol mice, the relative tumor volume was approximately 1000% in the CV790 study and approximately 600% in the CV890 study. The relative tumor volumes of mice freated with virus alone were 250% (CV790) and 520% (CV890) while the relative tumor volumes for mice freated with doxorubicin alone were 450% with 280% in the CV790 study and 500% in the CV890 study. Example 12: In vitro characterization of melanocyte-specific TRE-containing adenoviral constructs An especially useful objective in the development of melanocyte cell-specific adenoviral vectors is to treat patients with melanoma. Methods are described below for measuring the activity of a melanocyte-specific TRE and thus for determining whether a given cell allows a melanocyte-specific TRE to function. Cells and Culture Methods Host cells such as, HepG2 (liver); Lovo (colon); LNCaP (prostate); PMEL (melanoma); SKMel (melanoma); G361 (melanoma) and Me Wo cells are obtained at passage 9 from the American Type Culture Collection (Rockville, MD). Me Wo cells are maintained in RPMI 1640 medium (RPMI) supplemented with 10% fetal bovine serum (FBS; Intergen Corp.), 100 units/mL of penicillin, and 100 units/mL streptomycin. MeWo cells being assayed for luciferase expression are maintained in 10% strip-serum (charcoal/dexfran freated fetal bovine serum to remove T3, T4, and steroids; Gemini Bioproduct, Inc., Calabasas, CA) RPMI. Transfections of MeWo Cells For transfections, MeWo cells are plated out at a cell density of 5 x 10 5 cells per 6- cm culture dish (Falcon, NJ) in complete RPMI. DNAs are introduced into MeWo cells after being complexed with a 1 :1 molar lipid mixture of N-[l-(2,3-dioleyloxy)propyl- NNN-frimethylammonium chloride (DOTAP™; Avanti Polar Lipids, AL) and dioleoyl- phosphatidylethanolamine (DOPE™; Avanti Polar Lipids, AL); DΝA/lipid complexes are prepared in serum-free RPMI at a 2:1 molar ratio. Typically, 8 μg (24.2 nmole) of DΝA is diluted into 200 μL of incomplete RPMI and added dropwise to 50 nmole of transfecting, lipids in 200 μL of RPMI with gentle vortexing to insure homogenous mixing of components. The DNA/lipid complexes are allowed to anneal at room temperature for 15 minutes prior to their addition to MeWo cells. Medium is removed from MeWo cells and replaced with 1 mL of serum-free RPMI followed by the dropwise addition of DNA/lipid complexes. Cells are incubated with complexes for 4-5 hours at 37°C, 5% CO 2 . Medium was removed and cells washed once with PBS. The cells were then trypsinized and resuspended in 10% strip-serum RPMI (phenol red free). Cells were replated into an opaque 96-well tissue culture plate (Falcon, NJ) at a cell density of 40,000 cells/well per 100 μL media and assayed. Plaque assays To determine whether the adenoviral constracts described above replicate preferentially in melanocytes, plaque assays are performed. Plaquing efficiency is evaluated in the following cell types: melanoma cells (MeWo), prostate tumor cell lines (LNCaP), breast normal cell line (HBL-100), ovarian tumor cell line (OVCAR-3, SK-OV- 3), and human embryonic kidney cells (293). 293 cells serve as a positive confrol for plaquing efficiency, since this cell line expresses Ad5 EIA and EIB proteins. For analyzing constracts comprising a melanocyte-specific TRE, cells that allow a melanocyte-specific TRE to function, such as the cell lines provided above and cells that do not allow such function, such as HuH7, HeLa, PA-1, or G361, are used. The plaque assay is performed as follows: Confluent cell monolayers are seeded in 6-well dishes eighteen hours before infection. The monolayers are infected with 10-fold serial dilutions of each virus. After infecting monolayers for four hours in serum-free media (MEM), the medium is removed and replaced with a solution of 0.75% low melting point agarose and tissue culture media. Plaques are scored two weeks after infection. Example 13: Construction of a replication-competent adenovirus vector with a CEA-TRE and a EMCV IRES Using a strategy similar to Example 1, the TRE fragment from Carcinembryonic antigen (CEA)(Table 3, SEQ ID NO:14) is used to construct virus designated CV873. A PinAI fragment containing the CEA-TRE was cloned into the PinAI site in front of El A CP627 for the transcriptional confrol. The resultant plasmid CP1080 is used together with pBHGE3 to generate CV873. Example 14: In vitro and In vivo assays of anti-tumor activity An especially useful obj ective in the development of urothelial cell-specific adenoviral vectors is to treat patients with bladder cancer. An initial indicator ofthe feasibility is to test the vector(s) for cytotoxic activity against cell lines and tumor xenografts grown subcutaneously in Balb/c nu/nu mice. In vitro characterization of CV876 Viras yield assay for CV876 5 X 10 5 293, RT-4, SW780, PA-1, G361, MKNI, HBL-100, Fibroblast (from lung) and Smooth muscle cells (from bladder) were plated into each well of six-well plates. Twenty-four hours later, medium was aspirated and replaced with 1ml of serum-free RPMI 1640 containing CV802 (wt.Ad5 with E3) or CV876 at a MOI of 2 pfu/cell. After a 4-h incubation at 37°C, cells were washed with prewarmed PBS, and 2ml of complete RPMI 1640 were added to each well. After an additional 72h at 37°C, the cells were scraped into medium and lysed by three freeze-thaw cycles. The lysates were tested for viras production by triplicate plaque assay for 8-10 days under semisolid agarose on 293 cells. Unlike wt. Ad5, CV802 which grows well in all ofthe cells tested, CV876 replicates much better in permissive cells (293, RT-4 and SW780) than in non-permissive cells (PA-1, G361, MKNI, HBL-100 and primary cells) by about 100-10000 fold. Noticeably, the replication in SW780 for CV876 is about 100 fold less than CV802, which indicates the limitation of this viras in efficacy. Growth curve experiment for CV876 5 X 10 5 RT-4, PA-1, Smooth muscle and Fibroblast cells were plated into each well of six- well plates. Twenty-four hours later, medium was aspirated and replaced with 1ml of serum-free RPMI 1640 containing CV802 (wt.Ad5 with 133) or CV876 at a MOI of 2 pfu/cell. After a 4-h incubation at 37°C, cells were washed with prewarmed PBS, and 2ml of complete RPMI 1640 were added to each well. At different time points of 0, 12, 24, 36, 48, 72, 96 and 120h, the cells were scraped into medium and lysed by three freeze-thaw cycles. The lysates were tested for viras production by friplicate plaque assay for 8-10 days under semisolid agarose on 293 cells. Very similar as in viras yield assay, CV876 replicates well only in RT-4 but not in primary cells and PA-1 over a 120h period of time. However, CV876 does show a delay of replication in RT-4 compared to CV802. Cytopathic effect assay for CV876 5 X 10 5 293, RT-4, SW780, PA-1, MKNI and LNCap were plated into each well of six-well plates. Twenty-four hours later, medium was aspirated and replaced with 1ml of serum-free RPMI 1640 containing CV802 (wt.Ad5 with E3) or CV876 at increasing MOI from 0.001 to 10 (the data shown was at MOI 1). After a 4-h incubation at 37°C, medium was replaced with 3ml of complete RPMI 1640 and incubated at 37°C for 6-8 days when cytopathic effect was observed for CV802 at MOI 0.01. CV802 shows efficacy in all the cells tested while CV876 only kills the permissive cells (293, RT-4 and SW780) but not the non-permissive cells (PA-1, MKN-1 and LNCap). MTT assay for CV876 2 X 10 4 293, RT-4, SW780, MKNI, PA-1, HBL-100, Smooth muscle cells (from bladder) and Fibroblast (from lung) were plated into each well of 96-well plates. Twenty- four hours later, the cells were infected with CV802 and CV876 at increasing MOI from 0.001 to 10 in complete RPMI 1640. A rapid colorimefric assay for cell growth and survival was run at different time point of day 1, 3,5,7 and 10. The medium was replaced by 50ul of MTT at lmg/ml solution, which is converted to an insoluble purple formazan by dehydrogenase enzymes present in active mitochondria of live cells. After 3-4h incubation at 37°C, the solution was replaced by isopropanol and the plates were incubated at 30°C for lh and read at 560nm test wavelength and 690nm reference wavelength. Similar as the results in CPE assay, CV876 shows efficacy only in permissive cells but not in non-permissive cells. Again, in RT-4 and SW780, CV876 kills the cells much slower than CV802. In vitro characterization of CV882 Virus yield assay for CV882 5 X 10 5 293, RT-4, SW780, G361, LNCap, HBL-100, MKNI, PA-1, Fibroblast and Smooth muscle cells were plated into each well of six-well plates. Twenty-four hours later, medium was aspirated and replaced with 1ml of serum-free RPMI 1640 containing CV802 (wt.Ad5 with E3) or CV882 at a MOI of 2 pfu/cell. After a 4-h incubation at 37°C, cells were washed with prewarmed PBS, and 2ml of complete RPMI 1640 were added to each well. After an additional 72h at 37°C, the cells were scraped into medium and lysed by three freeze-thaw cycles. The lysates were tested for viras production by triplicate plaque assay for 8-10 days under semisolid agarose on 293 cells. The replication of CV882 in permissive cells (293, RT-4 and SW780) is comparable to CV802 (the difference is less than 100 fold) while it shows over 1000- 1000000 fold difference in non-permissive cells (G361, LNCap, HBL-100, MKNI, PA-1 and primary cells). Growth curve experiment for CV882 5 X 10 5 RT-4, PA-1, and Fibroblast cells were plated into each well of six- well plates. Twenty-four hours later, medium was aspirated and replaced with 1ml of serum- free RPMI 1640 containing CV802 (wt.Ad5 with E3) or CV882 at a MOI of 2 pfu/cell. After a 4-h incubation at 37°C, cells were washed with prewarmed PBS, and 2ml of complete RPMI 1640 were added to each well. At different time points of 0, 12, 24, 36, 48, 72, 96 and 120h, the cells were scraped into medium and lysed by three, freeze-fhaw cycles. The lysates were tested for viras production by friplicate plaque assay for 8-10 days under semisolid agarose on 293 cells. Very similar as in viras yield assay, CV882 replicates well only in RT-4 but not in primary cells and PA-1 over a 120h period of time. Additionally, CV882 shows better repUcation in RT-4 compared to CV876. Cytopathic effect assay for CV882 5 X 10 5 293, RT-4, SW780, HBL-1 00, G361, PA-1 and Fibroblast cells were plated into each well of six- well plates. Twenty-four hours later, medium was aspirated and replaced with 1ml of serum-free RPNI 1640 containing CV802 (wt.Ad5 with E3) or CV882 at increasing MOI from 0.001 to 10 (the data shown was at MOI 1). After a 4-h incubation at 37°C, medium was replaced with 3ml of complete RPMI 1640 and incubated at 37°C for 6-8 days when cytopathic effect was observed for CV802 at MOI 0.01. CV802 shows efficacy in all the cells tested while CV882 only kills the permissive cells (293, RT-4 and SW780) but not the non-permissive cells (HBL-100, G361, PA-1 and Fibroblast cells). MTT assay for CV882 2 X 10 4 RT-4, SW780, PA-1, HBL-100, UI 18 and Fibroblast were plated into each well of 96-well plates. Twenty-four hours later, the cells were infected with CV802 and CV882 at increasing MOI from 0.001 to 10 in complete RPMI 1640. A rapid colorimefric assay for cell growth and survival was run at different time points of day 1, 3, 5, 7 and 10. The medium was replaced by 50ul of MTT at lmg/ml solution, which is converted to an insoluble purple formazan by dehydrogenase enzymes present in active mitochondria of live cells. After 3-4h incubation at 37°C, the solution was replaced by isopropanol and the plates were incubated at 30°C for lh and read at 560nm test wavelength and 690nm reference wavelength. Similar as the results in CPE assay, CV882 shows efficacy only in permissive cells but not in non-permissive cells. In Vitro Characterization of CV884 Viras yield assay for CV884 5 X 10 5 293, RT-4, SW780, G361, LNCap, HBL-100, MKNI, PA-1, Fibroblast and Smooth muscle cells were plated into each well of six-well plates. Twenty-four hours later, medium was aspirated and replaced with 1ml of serum-free RPMI 1640 containing CV802 (wt.Ad5 with E3) or CV984 at a MOI of 2 pfu/cell. After a 4-h incubation at 37°C, cells were washed with prewarmed PBS, and 2ml of complete RPMI 1640 were added to each well. After an additional 72h at 37°C, the cells were scraped into medium and lysed by three freeze-thaw cycles. The lysates were tested for viras production by friplicate plaque assay for 8-10 days under semisolid agarose on 293 cells. The replication of CV884 is very similar as CV802 in permissive cells (293, RT-4 and SW780) but shows over 1000 fold difference with CV802 in non-permissive cells (G361, LNCap, HBL-100, MKNI, PA-1 and primary cells). CV884 shows better efficacy than CV876 and CV882 without losing much specificity. Growth curve experiment for CV884 5 X 10 5 RT-4, PA-1, Smooth muscle and Fibroblast cells were plated into each well of six- well plates. Twenty-four hours later, medium was aspirated and replaced with 1ml of serum-free RPMI 1640 containing CV802 (wt.Ad5 with E3) or CV884 at a MOI of 2 pfu/cell. After a 4-h incubation at 37°C, cells were washed with prewarmed PBS, and 2ml of complete RPMI 1640 were added to each well. At different time points of 0, 12, 24, 36, 48, 72, 96 and 120h, the cells were scraped into medium and lysed by three freeze-thaw cycles. The lysates were tested for viras production by friplicate plaque assay for 8-10 days under semisolid agarose on 293 cells. Very similar as in viras yield assay, CV884 replicates very well only in RT-4 (similar as CV802) but not in primary cells and PA-1. Again, the replication of CV884 is better than CV882 and CV876. Cytopathic effect assay for CV884 5 X 10 5 293, RT-4, SW780, G361, PA-1 and Fibroblast cells were plated into each well of six-well plates. Twenty-four hours later, medium was aspirated and replaced with lml of serum-free RPMI 1640 containing CV802 (wt.Ad5 with E3) or CV884 at increasing MOI from 0.001 to 10 (the data shown was at MOI 1). After a 4-h incubation at 37°C, medium was replaced with 3ml of complete RPMI 1640 and incubated at 37°C for 6-8 days when cytopathic effect was observed for CV802 at MOI 0.01. CV802 shows efficacy in all the cells tested while CV884 only kills the permissive cells (293, RT-4 and SW780) but not the non-permissive cells (G361, PA-I and Fibroblast cells). MTT assay for CV884 2 X 10 4 293, RT-4, SW780, UI 18, Fibroblast and Smooth muscle cells were plated into each well of 96-well plates. Twenty-four hours later, the cells were infected with CV802 and CV884 at increasing MOI from 0.001 to 10 in complete RPMI 1640. A rapid colorimefric assay for cell growth and survival was run at different time points of day 1, 3, 5, 7 and 10. The medium was replaced by 50ul of MTT at lmg/ml solution which is converted to an insoluble purple formazan by dehydrogenase enzymes present in active mitochondria of live cells. After 3-4h incubation at 37°C, the solution was replaced by isopropanol and the plates were incubated at 30°C for lh and read at 560nm test wavelength and 690nm reference wavelength. Similar as the results in CPE assay, CV884 shows strong efficacy (similar as wt. Ad5) only in permissive cells but not in non-permissive cells. In vivo activity of CV808 Mice were given subcutaneous (SC) injections of 1 x 10 6 sW780 cells. When tumors grew to about 500 mm 3 , CV808 was introduced into the mice (5 X 10 7 PFU of viras in 0.1 ml PBS and 10% glycerol) infratumorally. Confrol mice received vehicle alone. Tumor sizes were measured weekly. The results are shown in FIG. 11. The data indicate that CV808 was effective at suppressing tumor growth. While it is highly possible that a therapeutic based on the viruses described here would be given infralesionally (i.e., direct injection), it would also be desirable to determine if intravenous (IV) administration of adenovirus vector can affect tumor growth. If so, then it is conceivable that the viras could be used to treat metastatic tumor deposits inaccessible to direct injection. For this experiment, groups of mice bearing bladder epithelial tumors are inoculated with 10 8 to 10 10 PFU of an adenoviral vector by tail vein injection, or with buffer used to carry the viras as a negative control. The effect of IV injection ofthe adenoviral vector on tumor size is compared to vehicle freatment. Example 15: Synergistic Effect of CV 890 with Chemotherapeutics Materials and Methods Cells. Hepatocellular carcinoma cell lines HepG2, Heρ3B, PLC/PRF/5, SNU449, and Sk-Hep-1, Chang liver cell (human normal liver cells), as well as other tumor cell lines PA-1 (ovarian carcinoma), UM-UC-3 (bladder carcinoma), SW 780 (bladder carcinoma), HBL100 (breast epithelia), Colo 201 (Colon adenocarcinoma), U 118 MG (glioblastoma) and LNCaP (prostate carcinoma) were obtained from the American Type Culture Collection. HuH-7 (liver carcinoma) was a generous gift of Dr. Patricia Marion (Stanford University). 293 cells (human embryonic kidney containing the El region of Adenoviras) were purchased from Microbix, Inc. (Toronto, Canada). The primary cells nBdSMC (normal human bladder smooth muscle cells), nHLFC (normal human lung fibroblast cells), and nHMEC (normal human mammary epithelial cells) were purchased from Clonetics (San Diego, California). All tumor cell lines were maintained in RPMI 1640 (BioWhittaker, Inc.) supplemented with 10% fetal bovine serum (Irvine Scientific), 100 U/ml penicillin and 100 ug/ml streptomycin. Primary cells were maintained in accordance with vendor instructions (Clonetics, San Diego). Cells were tested for the expression of AFP by immunoassay (Genzyme Diagnostics, San Carlos, CA). Viras yield and one-step growth curves. Six well dishes (Falcon) were seeded with 5x10 5 cells per well of calls of interest 24 hrs prior to infection. Cells were infected at an multiplicity of infection (MOI) of 2 PFU/cell for three hours in serum-free media. After 3 hours, the virus containing media was removed, monolayers were washed three times with PBS, and 4 ml of complete media (RPMI1640 + 10% FBS) was added to each well. 72 hours post infection, cells were scraped into the culture medium and lysed by three cycles of freeze-thaw. The one-step growth curves time points were harvested at various time points after infection. Two independent infections of each vims cell-combination were titered in duplicate on 293 cells (Yu et al., 1999, Cancer Sesearch, 59:1498-1504. Northern blot analysis. Hep3B or HBL100 cells were infected at an MOI of 20 PFU/cell (plaque forming unit per cell) with either CV802 or CV890 and harvested 24 hours post infection. Total cell RNA was purified using the RNeasy protocol (Qiagen). The Northern blot was conducted using NorthernMax Plus reagents (Ambion, Austin, Texas). 5ug of RNA was fractionated on a 1% agarose, formaldehyde-based denaturing gel and transferred to a BrightStar-Plus (Ambion) positively charged membrane by capillary transfer. The antisense RNA probes for EIA (adenoviras genome 501bp to 1141bp) or EIB (1540bp-3910bp) were PCR products cloned in pGEM-T easy (Promega) and franscription labeled with [α 32 P] UTP. Blots were hybridized at 68°C for 14 hours with ZipHyb solution and washed using standard methods (Ambion). Membranes were exposed to BioMax film (Kodak). Western blot analysis. Hep3B or HBL100 cells were infected at MOI of 20 PFU/cell with either CV802 or CV890 and harvested 24 hours post infection. Cells were washed with cold PBS and lysed for 30 min on ice in (50mM Tris, pH8.0, 150 mM NaCl, 1% IGEPAL CA360 a NP40 equivalent (Sigma), 0.5% sodium deoxycholate, and protease inhibitor cocktail from (Roche, Palo Alto, California). After 30 min centrifugation at 4C, the supernatant was harvested and the protein concenfration determined with protein assay ESL kit (Roche). Fifty micrograms of protein per lane were separated on 816% SDS- PAGE and electroblotted onto Hybond ECL membrane (Amersham Pharmacia, Piscataway, New Jersey). The membrane was blocked overnight in PBST (PBS with 0.1% Tween-20) supplemented with 5% nonfat dry milk. Primary antibody incubation was done at room temperature for 2-3 hrs with PBST/1 % milk diluted antibody, followed by wash and 1 hr incubation with diluted horseradish peroxidase-conjugated secondary antibody (Santa Cruz Biotechnology Inc., Santa Cruz, California). Enhanced chemiluminescence (ECL; Amersham Pharmacia) was used for the detection. EIA antibody (clone M58) was from NeoMarkers (Fremont, California), E1B-21 kD antibody was from Oncogene (Cambridge, Massachusetts). All antibodies were used according manufacturer's instruction. Cell viability assay and statistical analysis. To determine the cell killing effect of viras and chemotherapeutic agent in combination freatment, a cell viability assay was conducted as previously described with modifications (Denizot, 1986, Journal Immunology. Methods, 89:271-277). On 96 well plates, cells of interest were seeded at 10,000 calls per well 48 hr prior to infection. Cells were then freated with viras alone, drag alone, or in combination. Cell viability was measured at different time points by removing the media, adding 50 μl of lmg/ml solution of MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5- diphenyl- 2 H-tetrazolium bromide) (Sigma, St. Louis, MO) and incubating for 3 hrs at 37°C. After removing the MTT solution, the crystals remaining in the wells were solubilized by the addition of 50 μl of isopropanol followed by 30C incubation for 0.5 hr. The absorbency was determined on a microplate reader (Molecular Dynamics) at 560 nm (test wavelength) and 690 nm (reference wavelength). The percentage of surviving cells was estimated by dividing the OD 55 o-OD 65 o of viras or drag freated cells by the OD55 0 -OD 650 of control cells. one week prior to tumor implantation. Xenografts were established by injecting lxl 0 6 Hep3B, HepG2 or LNCaP cells suspended in lOOμl of RPMI 1640 media subcutaneously. When tumors reached between 200 mm and 300 mm , mice were randomized and dosed with 100 μl of test article via intratumoral or the tail vein injection. Tumors were measured in two dimensions by external caliper and volume was estimated by the formula [length (mm) x width (mm) 2 ]/2. Animals were humanely killed when their tumor burden became excessive. Serum was harvested weekly by retro-orbital bleed. The level of AFP in the serum was determined by AFP Immunoassay kit (Genzyme Diagnostics, San Carlos, CA). The difference in mean tumor volume and mean serum AFP concenfration between freatment groups was compared for statistical significance using the unpaired, two-tailed, t- test. Transcription and Translation of EIA/EIB Bicisfronic Cassette of CV890 in Different Cells. In wild type adenoviras infection, EIA and EIB genes produce a family of alternatively spliced products. It has been found that there are five EIA mRNAs, among them 12S (880 nucleotides, nts) and 13S (1018 nts) mRNAs are the dominant ones that are expressed both early and late after infection. The 12S and 13S mRNAs encode the gene product of 243 amino acids (243R) and 289 amino acids (289R) respectively (reviewed by Shenk, 1996). The two major EIB transcripts that code for 19kD and 55kD proteins are 12S (1031 nts) and 22S (2287 nts) mRNAs. EIB 12S mRNA only codes the 19kD product, whereas the 22S mRNA codes for both 19kD and 55kD products due to different initiation sites during franslation. In the current study, the generation of EIA-IRES-EIB bicisfronic cassette was expected to change the pattern of El A and EIB transcripts in viral infection. Therefore, Northern blot analysis was conducted to evaluate the steady-state level of El A and EIB transcripts. First, CV802 or CV890 were infected to Hep3B (AFP) or HBL100 (AFP) cells for 24 hours. The total RNA samples were separated on agarose gels and processed for Northern blot by hybridizing to antisense RNA probes. The Northern blot with EIA probe visualized the 12S and 13S mRNAs in both wild type CV802 infected cells. For CV890, EIA transcripts can only be seen in Hep3B cells, indicating the conditional franscription of EIA. It is of interest to find that in CV890, there is only one large franscript (about 3.51Kb), whereas the 12S and 13S mRNAs are no longer present. This large franscript indicates the continuous franscription of EIA-IRES-EIB bicisfronic cassette, suggesting an alteration of viral EIA splicing pattern in CV890. Transcription of EIB from CV890 also appears to be AFP-dependent. It is clear that both 12S and 22S mRNAs of EIB were present in wild type CV802 samples, whereas the 128 mRNA and an enlarged 22S mRNA (3.5Kb) appeared in CV890 infected cells. Obviously, the identity of this enlarged mRNA is the same 3.5Kb transcript as visualized in EIA blot, which is from the transcription of El A/EIB bicisfronic cassette. Therefore, the EIB mRNA is tagged after EIA mRNA in this large franscript. This large transcript contains all the coding information for EIA, EIB 19kD and EIB 55kD. The mRNA splice pattern that appears in CV802 is not valid in CV890, thel2S mRNA with EIB probe disappeared. Meanwhile, in the EIB Northern blot, due to the selection of our EIB probe (1540bρ-3910bρ), mRNA of the Adenovirus gene IX (3580bp-4070bp), the hexon-associated protein, was also detected. In CV890 infected Hep3B cells, gene IX expression is equivalent to that of CV802, whereas in CV890 infected HBL100, its expression was also completely shut down. This result further demonstrated that the AFP controlled EIA/EIB expression is the key for late gene expression as well as viral replication. Results ofthe same samples in the Western blot also indicate that CV890 has AFP dependent expression of EIA and EIB. Under our experimental conditions, EIA expression level of CV890 in Hep3B cells is similar to that of CV802. However, when EIB 19kD protein was detected, it was found that the expression level was much lower than CV802 EIA. Previously, it has been addressed that IRES-mediated second gene has less expression (Mizuguchi et al., 2000, Mol. Ther. 1 :376-382). Taken together, CV890 infection in permissive Hep3B cells can produce normal amounts of El A and lesser amounts of EIB proteins capable of initiating a normal productive infection. In AFP " cells, however, this process was attenuated due to a lack of EIA and EIB gene franscription and translation. These data demonstrated that the expression of both EIA and EIB genes are under the control of AFP TRE and the artificial El A/El B bicisfronic cassette is functioning properly in CV890. In Vitro Replication Specificity of CV890 in Tumor Cells and Primary Cells. From in vitro comparison of viras yield, CV890 has a better specificity profile than CV732 (CV732 is an AFP-producing, cell-specific adenoviras variant in which the EIA gene is under confrol of AFP-TRE). In order to gain further insights of using CV890 in liver cancer therapy, more tumor cell lines and primary cells were tested to characterize in vitro virus replication. First, all cells in the study were analyzed for their AFP status by AFP immune assay. Based on AFP produced in the cells and media, all the cells were divided into three groups, high (>2.5 μg/10 6 cells/10 days), low (<0.6 μg/10 6 cells/10 days) and none (undetectable in our study) (Table 7). It was confirmed that replication of CV890 in different cell lines correlates well with the AFP status ofthe host cell. Among the group of liver cell lines, CV890 only replicates well in AFP + cells, including Hep3B, HepG2, Huh7, SNU449 and PLC/PRF/5. The amount of AFP required for the promoter activity seems very low as one ofthe hepatoma cell lines, SNU449, a previous reported AFP " cell (Park et al., 1995, Int. J. Cancer 62:276-282), produces very low AFP (about 60 ng/10 6 cells/10 days) compared to other cells. Nevertheless, even with very low amount of AFP, SNU449 cells can still support CV890 replication to the extent comparable to cells producing significantly higher levels of AFP such as HepG2. Compared to CV802, CV890 is attenuated 5,000 to 100,000 fold in cells that do not produce AFP, including the hepatoma cell Sk-Hepl and Chang liver cell, other tumor cells and primary cells. Taken together the results indicate that CV890 has shown a good specificity profile from a broad spectrum of tumor cells. Among them, only the AFP + liver cells, AFP production level from high to low, are permissive for CV890. In another experiment, CV890 was compared to CV802 for their single step growth curves on different cells. Results demonstrated that CV890 has a similar growth kinetics to wild-type CV802 in AFP + cells except that viras yields are slightly lower (2-8 fold) in low AFP producing cells. In consideration of experimental error, there is no dramatic difference in the replication of CV890 and CV802 in AFP + hepatoma cells. However, the growth curves of CV890 in AFP " cells showed clear attenuation. During a 5 day experiment, CV890 failed to replicate in AFP " cells including hepatoma cell (Change liver) and primary cells (nHLFC). From all the in vitro virus replication studies, it is clear that replication of CV890 is under the tight confrol of AFP-TRE and this adenovirus variant has an excellent specificity profile of preferentially targeting AFP producing hepatocellular carcinoma cells. In Vivo Specificity and Efficacy of CV890. CV890 specificity was also evaluated in animals bearing prostate cancer LNCaP xenografts. In this in vivo test, nude mice with prostate xenograft were intravenously injected with either CV890 or CV787, a prostate cancer specific adenoviras variant (Yu et al., 1999, Cancer Research, 59:4200-4203). Tumor volumes were documented and indicated that only CV787 had a significant antitumor efficacy in LNCaP xenografts, while tumors in the animals treated with CV890 grew, from 400 mm 3 to approximately 1200 mm 3 in six weeks, similar to the group treated with vehicle. This study indicates that CV890 does not attack LNCaP xenograft and keeps the good specificity profile under in vivo conditions. To evaluate in vivo antitumor efficacy of CV890, different studies were carried out in the nude mouse model harboring human hepatoma xenografts. First, BALB/c nu/nu mice with HepG2 or Hep3B xenografts were established, animals were further challenged with single dose or multiple doses of CV890 into the tumor mass (intratumoral adminisfration, IT) or via their tail vein (infravenous administration, IV). Tumor volume and the level of serum AFP were monitored weekly after the start of freatment, and hence the efficacy ofthe freatment was determined. The in vitro cytotoxicity study has demonstrated that CV890 has a better cytolytic effect than CV732. In order to further examine their antitumor activity, we first conducted animal study to compare CV890 to CV732. Animals harboring 300 mm Hep3B xenograft were grouped (n=6) and injected with vehicle alone (confrol group), CV890 (lxlO 11 particles/dose, CV890 group), or CV732 (lxl 0 11 particles/dose, CV732 group). The Hep3B xenograft is a very aggressive tumor model and tumors grow very fast. Most animals can not survive long because of excessive tumor burden. During a six week study, single intravenous administration of CV890 have shown significant tumor growth inhibition, whereas confrol mice had over 10 fold tumor growth at week 5. In the group freated with CV732, single dose IV injection also reduced the tumor growth as compared to confrol group, however, it was much less effective compared to CV890. For example, the average tumor volume ofthe CV890 freated group dropped from 312 mm 3 to 219 mm 3 , while tumor volume increased from 308 mm 3 to 1542 mm 3 5 weeks after freatment in confrol. Both control group and the CV732 group were terminated at week 5 because excessive tumor size. Previously, CV732 has been demonsfrated to resfrict the hepatoma tumor from growth after 5 doses of infravenous administration. Similar efficacy can be achieved with just a single infravenous administration of CV890, indicating that under in vivo conditions, CV890 has better efficacy than CV732 in hepatoma xenografts. In this experiment, 4 out of five CV890 freated mice were tumor free three weeks after freatment. However, in CV732 group, xenografts in two mice stopped growing but none of treated animals were tumor free through the six-week experiment. There was no tumor reduction in this group or the confrol group of animals. By statistical analysis, the differences in mean relative tumor volumes and serum AFP concenfrations between CV890 treated and CV732 freated or vehicle treated tumors are significant (p<0.01)). Taken together, these studies suggest that CV890 has a significant antitumor activity and its oncolytic efficacy is better than CV732, an adenoviras variant similar to AvEla04I, in which the AFP TRE was applied to confrol EIA alone (Hallenback et al, 1999, Hum. Gene. Ther., 10:1721-1733). Synergistic Antitumor Efficacy of CV890 in Combination with Chemotherapeutic Agents In this example, different chemotherapeutic agents were tested in combination with CV890 for their in vitro killing effect in Hep3B or HepG2 cells. Drag concentrations were optimized to the extent that they would not generate extensive cytotoxic effect on their own. Under such conditions, some agents had shown higher cell killing effect in combination with CV890. Among them, doxorabicin, a drag currently used in treatment of HCC showed synergistic cytotoxicity with CV890. In experiments using doxorabicin together with CV890 on Hep3B cells, doxorabicin at lOng/ml did not generate cytotoxicity, whereas CV890 at an MOI of 0.01 (pfu/cell) only had about 35% of cell killed at day 9. However, when both were applied together, 90% cells were killed 9 days after treatment. In order to determine the potential synergistic effect from the combination freatment, the MTT cell viability data were subjected to further statistical analysis. Figure 10 shows a representative IC 50 isobologram of doxorabicin and CV890 on Hep3B cells at day 5. First, the dose-response curves of doxorubicin alone or CV890 alone were made. Based on the original theory of Steel and Peckham (1993) and method by Aoe et al. (1999), three isoeffect curves (mode I and mode 2a, 2b) were constructed. From this isobologram, several data points were in the synergy or additive area, indicating that combination of CV890 and doxorabicin provides synergistic effect on killing of Hep3B cells. Although CV890 alone has good antitumor activity, we applied combination therapy with doxorubicin for in vivo evaluation of synergy. Animals harboring 300 mm 3 Hep3B xenografts were grouped (n=6) and injected with vehicle alone (control group), CV890 alone (lxlO 11 particles/dose, CV890 group), doxorabicin alone (lOmg/kg, doxorabicin group), or CV890 in combination with doxorabicin (combination group). Figure 11 shows weekly change ofthe relative tumor size normalized to 100% at day 1. In this experiment, by week six, all animals in the confrol group had excessive tumor which has increased by 700% of baseline, whereas in CV890 group and combination group, animals had either tumor free or tumor reduction. Ofthe eight Hep3B xenografts, treated with CV890, three animals (37.5%) had no palpable tumor at week 5, another three animals had tumor regressed by more than 60%. In combination group, four out of eight animals were tumor free from week 5, another four animals had tumor reduction about 90%. All the animals in the CV890 and combination group were alive and tumor was suppressed even ten weeks following freatment whereas the control animals were sacrificed for excessive tumor burden after week 6. Furthermore, CV890 also caused a drop in the serum AFP concenfration in these mice. Statistical analysis shows that differences in mean relative tumor volumes and serum AFP concenfrations between CV890 and vehicle treated group or combination and doxorabicin treated group are significant at different times (p<0.005). The strong efficacy in the combination treatment shows that single IV injection of CV890 in combination of doxorubicin can eradicate aggressive Hep3B xenografts in most ofthe animals. Table 7. AFP production in different tumor cells AFP CELLS (ng/10 6 cells/10days) Hep3B 2645 HepG2 3140 High HuH7 4585 SNU449 60 Low PLC/PRF/5 600 Chang 0 SK-Hepl 0 HBL100 0 None PA-1 0 LoVo TABLE 1 IRES SEQUENCES SEQ ID NO :1 A 519 base pair IRES obtainable from encephelomycarditis vims (EMCV). l GACGΓCGACΓAATTCCGGTTATTTTCCACCATATTGCCGTCTTTTGGCAA Sail 51 TGTGAGGGCCCGGAAACCTGGCCCTGTCTTCTTGACGAGCATTCCTAGGG 101 GTCTTTCCCCTCTCGCCAAAGGAATGCAAGGTCTGTTGAATGTCGTGAAG 151 GAAGCAGTTCCTCTGGAAGCTTCTTGAAGACAAACAACGTCTGTAGCGAC 201 CCTTTGCAGGCAGCGGAACCCCCCACCTGGCGACAGGTGCCTCTGCGGCC 251 AAAAGCCACGTGTATAAGATACACCTGCAAAGGCGGCACAACCCCAGTGC 301 CACGTTGTGAGTTGGATAGTTGTGGAAAGAGTCAAATGGCTCTCCTCAAG 351 CGTATTCAACAAGGGGCTGAAGGATGCCCAGAAGGTACCCCATTGTATGG 401 GATCTGATCTGGGGCCTCGGTGCACATGCTTTACATGTGTTTAGTCGAGG 451 TTAAAAAACGTCTAGGCCCCCCGAACCACGGGGACGTGGTTTTCCTTTGA Sail 501 AAAACACGATGTCGAOGTC SEQ ID NO:2 An IRES obtainable from vascular endothelial growth factor (VEGF). 1 ACGTAGTCGACAGCGCAGAGGCTTGGGGCAGCCGAGCGGCAGCCAGGCCC Sail 51 CGGCCCGGGCCTCGGTTCCAGAAGGGAGAGGAGCCCGCCAAGGCGCGCAA 101 GAGAGCGGGCTGCCTCGCAGTCCGAGCCGGAGAGGGAGCGCGAGCCGCGC 151 CGGCCCCGGACGGCCTCCGAAACCATGGTCGACACGTA Sail SEQ ID NO:3 A 5'UTR region of HCV. 1 GCCAGCCCCCTGATGGGGGCGACACTCCGCCATGAATCACTCCCCTGTGAGGAACTACTG 61 TCTTCACGCAGAAAGCGTCTAGCCATGGCGTTAGTATGAGTGTCGTGCAGCCTCCAGGAC 121 CCCCCCTCCCGGGAGAGCCATAGTGGTCTGCGGAACCGGTGAGTACACCGGAATTGCCAG 181 GACGACCGGGTCCTTTCTTGGATTAACCCGCTCAATGCCTGGAGATTTGGGCGTGCCCCC 241 GCAAGACTGCTAGCCGAGTAGTGTTGGGTCGCGAAAGGCCTTGTGGTACTGCCTGATAGG 301 GTGCTTGCGAGTGCCCCGGGAGGTCTCGTAGACCGTGCACC (341) SEQ ID NO:4A 5'UTR region of BiP SEQ ID NO:4 1 . CCCGGGGTCACTCCTGCTGGACCTACTCCGACCCCCTAGGCCGGGAGTGAAGGCGGGACT 61 TGTGCGGTTACCAGCGGAAATGCCTCGGGGTCAGAAGTCGCAGGAGAGATAGACAGCTGC 121 TGAACCAATGGGACCAGCGGATGGGGCGGATGTTATCTACCATTGGTGAACGTTAGAAAC 181 GAATAGCAGCCAATGAATCAGCTGGGGGGGCGGAGCAGTGACGTTTATTGCGGAGGGGGC 241 CGCTTCGAATCGGCGGCGGCCAGCTTGGTGGCCTGGGCCAATGAACGGCCTCCAACGAGC 301 AGGGCCTTCACCAATCGGCGGCCTCCACGACGGGGCTGGGGGAGGGTATATAAGCCGAGT 361 AGGCGACGGTGAGGTCGACGCCGGCCAAGACAGCACAGACAGATTGACCTATTGGGGTGT 421 TTCGCGAGTGTGAGAGGGAAGCGCCGCGGCCTGTATTTCTAGACCTGCCCTTCGCCTGGT 481 TCGTGGCGCCTTGTGACCCCGGGCCCCTGCCGCCTGCAAGTCGAAATTGCGCTGTGCTCC 541 TGTGCTACGGCCTGTGGCTGGACTGCCTGCTGCTGCCCAACTGGCTGGCAAGATG (595) SEQ ID NO:5 A 5'UTR of PDGF SEQ ID NO:5 1 GTTTGCACCTCTCCCTGCCCGGGTGCTCGAGCTGCCGTTGCAAAGCCAACTTTGGAAAAA 61 GTTTTTTGGGGGAGACTTGGGCCTTGAGGTGCCCAGCTCCGCGCTTTCCGATTTTGGGGG 121 CTTTCCAGAΆAATGTTGCAΆAAΆAGCTAAGCCGGCGGGCAGAGGAAAACGCCTGTAGCCG 181 GCGAGTGAAGACGAACCATCGACTGCCGTGTTCCTTTTCCTCTTGGAGGTTGGAGTCCCC 241 TGGGCGCCCCCACACCCCTAGACGCCTCGGCTGGTTCGCGACGCAGCCCCCCGGCCGTGG 301 ATGCTGCACTCGGGCTCGGGATCCGCCCAGGTAGCCGGCCTCGGACCCAGGTCCTGCGCC 361 CAGGTCCTCCCCTGCCCCCCAGCGACGGAGCCGGGGCCGGGGGCGGCGGCGCCGGGGGCA 421 TGCGGGTGAGCCGCGGCTGCAGAGGCCTGAGCGCCTGATCGCCGCGGACCTGAGCCGAGC 481 CCACCCCCCTCCCCAGCCCCCCACCCTGGCCGCGGGGGCGGCGCGCTCGATCTACGCGTC 541 CGGGGCCCCGCGGGGCCGGGCCCGGAGTCGGCATG (575) TABLE 2 LITERATURE REFERENCES FOR IRES TABLE 3 TRE SEQUENCES Nucleotide sequence of a human uroplakin II 5' flanking region. Position +1 (the translational start site) is denoted with an asterisk. SEQ ID NO: 6 (number 1 of SEQ ID NO:6 corresponds to position -2239 with respect to the franslational start site). TCGATAGGTA CCCACTATAG GGCACGCGTG GTCGACGGCC CGGGCTGGTC 1 50 TGGCAACTTC AAGTGTGGGC CTTTCAGACC GGCATCATCA GTGTTACGGG 51 100 GAAGTCACTA GGAATGCAGA ATTGATTGAG CACGGTGGCT CACACCTGTA 101 150 ATCCCAACAC TCTGGGAGGC CAAGGCAGGT GGATCACTTG TGGTCAGGAG 151 200 TTTGAGACCA GCCTGGCCAA CATGGTGAAA CCTCATCTCT ACTAAAAATA 201 250 CAAAAATTAG CTGGGAATGG TGGCACATGC CTATAATCCC AGTTACTCAG 251 300 GAGGCTGAGG CAGGAGAATC ATTTGAACCT GGGAGGCAGA GGTTGCAGTG 301 350 AGCCGAGATC ACGCCACTGC ACTCCAGCCT GGGTGACACA GCGAGACTCT 351 400 GTCTCAAAAA AAAAAAAATG CAGAATTTCA GGCTTCACCC CAGACCCACT 401 450 GCATGACTGC ATGAGAAGCT GCATCTTAAC AAGATCCCTG GTAATTCATA 451 500 CGCATATTAA ATTTGGAGAT GCACTGGCGT AAGACCCTCC TACTCTCTGC 501 550 TTAGGCCCAT GAGTTCTTCC TTTACTGTCA TTCTCCACTC ACCCCAAACT 551 600 TTGAGCCTAC CCTTCCCACC TTGGCGGTAA GGACACAACC TCCCTCACAT 601 650 TCCTACCAGG ACCCTAAGCT TCCCTGGGAC TGAGGAAGAT AGAATAGTTC 651 700 GTGGAGCAAA CAGATATACA GCAACAGTCT CTGTACAGCT CTCAGGCTTC 701 750 TGGAAGTTCT ACAGCCTCTC CCGACAAAGT ATTCCACTTT CCACAAGTAA 751 800 CTCTATGTGT CTGAGTCTCA GTTTCCACTT TTCTCTCTCT CTCTCTCTCT 801 850 CAACTTTCTG AGACAGAGTT TCACTTAGTC GCCCAGGCTG GAGTGCAGGG 851 900 GCACAATCTC GGCTCACTGC AACCTCCACC TCCTGGGTTC AAGTGTTTCT 901 950 CCTGTCTCAG CCTCCCGAGT AGCTGGGATT ACAGGCACAC ACCACCGCGT 951 1000 TAGTTTTTGT ATTTTTGGTA GAGATGGTGT TTCGCCATAT TGGCCAGGCT 1001 1050 GATCTCGAAC TCCTGACCTC AGGTGATCCG CCCACCTCGG CCTCCCAAAG 1051 1100 TGCTGGGATT ACAGGCATGA GCCACCACGC CCGGCTGATC TCTTTTCTAT 1101 1150 TTTAATAGAG ATCAAACTCT CTGTGTTGCC TAGGCTGGTC TTGAACTCCT 1151 1200 GGCCTCGAGT GATCCTCCCA CCTTGGCCTC CCAAAGTGTT GAGATTACAG 1201 1250 GCATGAGCCA CTGTGCCTGG CCTCAGTTCT ACTACAAAAG GAAGCCAGTA 1251 1300 CCAGCTACCA CCCAGGGTGG CTGTAGGGCT ACAATGGAGC ACACAGAACC 1301 1350 CCTACCCAGG GCCCGGAAGA AGCCCCGACT CCTCTCCCCT CCCTCTGCCC 1351 1400 AGAACTCCTC CGCTTCTTTC TGATGTAGCC CAGGGCCGGA GGAGGCAGTC 1401 1450 AGGGAAGTTC TGTCTCTTTT TCATGTTATC TTACGAGGTC TCTTTTCTCC 1451 1500 ATTCTCAGTC CAACAAATGG TTGCTGCCCA AGGCTGACTG TGCCCACCCC 1501 1550 CAACCCCTGC TGGCCAGGGT CAATGTCTGT CTCTCTGGTC TCTCCAGAAG 1551 1600 TCTTCCATGG CCACCTTCGT CCCCACCCTC CAGAGGAATC TGAAACCGCA 1601 1650 TGTGCTCCCT GGCCCCCACA GCCCCTGCCT CTCCCAGAGC AGCAGTACCT 1651 1700 AAGCCTCAGT GCACTCCAAG AATTGAAACC CTCAGTCTGC TGCCCCTCCC 1701 1750 CACCAGAATG TTTCTCTCCC ATTCTTACCC ACTCAAGGCC CTTTCAGTAG 1751 1800 CCCCTTGGAG TATTCTCTTC CTACATATCA GGGCAACTTC CAAACTCATC 1801 1850 ACCCTTCTGA GGGGTGGGGG AAAGACCCCC ACCACATCGG GGGAGCAGTC 1851 1900 CTCCAAGGAC TGGCCAGTCT CCAGATGCCC GTGCACACAG GAACACTGCC 1901 1950 TTATGCACGG GAGTCCCAGA AGAAGGGGTG ATTTCTTTCC CCACCTTAGT 1951 2000 TACACCATCA AGACCCAGCC AGGGCATCCC CCCTCCTGGC CTGAGGGCCA 2001 2050 GCTCCCCATC CTGAAAAACC TGTCTGCTCT CCCCACCCCT TTGAGGCTAT 2051 2100 AGGGCCCAAG GGGCAGGTTG GACTGGATTC CCCTCCAGCC CCTCCCGCCC 2101 2150 CCAGGACAAA ATCAGCCACC CCAGGGGCAG GGCCTCACTT GCCTCAGGAA 2151 2200 CCCCAGCCTG CCAGCACCTA TTCCACCTCC CAGCCCAGCA 2201 2239 Nucleotide sequence of a mouse uroplakin II 5' flanking region. The franslational start site is denoted with an asterisk. SEQ ID NO:7 (number 1 of SEQ ID NO:7 corresponds to position -3592 with respect to the translational start site). CTCGAGGATCTCGGCCCTCTTTCTGCATCCTTGTCCTAAATCATTTTCAT 1 50 ATCTTGCTAGACCTCAGTTTGAGAGAAACGAACCTTCTCATTTTCAAGTT 51 100 GAAAAAAAAAAGAGGTTCAAAGTGGCTCACTCAAAGTTACAAGCCAACAC 101 150 TCACCACTACGAGTACAATGGCCACCATTAGTGCTGGCATGCCCCAGGAG 151 200 ACAGGCATGCATATTATTCTAGATGACTGGGAGGCAGAGGGGTGGCCTAG 201 250 TGAGGTCAGACTGTGGACAGATCAGGCAGATGTGGGTTCTGATCCCAATT 251 300 CCTCAGGCCGCAGAACTACTGTGGTTCAAGAAGGGGACAAAAGGACTGCA 301 350 GTCCGGAACAGGAGGTCCATTTGAGAGCTGACTGAGCAGAAGAGGAAAGT 351 400 GAAGAACTTCTGGGGCAAGAGCTTACCCTACTTTACAGCTTTGTTGTCTT 401 450 CTTTACTCCAGGGGCGTCCCTGGTACTCAGTAAATGTCTGTTGGCTTGAG 451 500 GAACATATGTGTAAGGAGGAAGGAGAGGGAACTTGAGGGAGTTAAGACTC 501 550 AAGAATCAATCAAGGAGAGGACAGCAGAGAAGACAGGGTTTGGGAGAGAG 551 600 ACTCCAGACATTGGCCCTGGTTCCCTTCTTGGCCACTGTGAAACCCTCCA 601 650 GAGGAACTGAGTGCTGTGGCTTTAAATGATCTCAGCACTGTCAGTGAAGC 651 700 GCTCTGCTCAAAGAGTTATCCTCTTGCTCCTGTGCCGGGGCCTCCCCCTC 701 750 CTCTCAGCTCCCAAACCCTTCTCAGCCACTGTGATGGCATAATTAGATGC 751 800 GAGAGCTCAGACCGTCAGGTCTGCTCCAGGAACCACCCATTTTCCCCAAC 801 850 CCCAGAGAAAGGTCCTAGTGGAAAAGTGGGGGCCACTGAAGGGCTGATGG 851 900 GGTTCTGTCCTTTCCCCCATGCTGGGTGGACTTAAAGTCTGCGATGTGTG 900 950 TAGGGGGTAGAAGACAACAGAACCTGGGGGCTCCGGCTGGGAGCAGGAGG 951 1000 AACTCTCACCAGACGATCTCCAAATTTACTGTGCAATGGACGATCAGGAA 1001 1050 ACTGGTTCAGATGTAGCTTCTGATACAGTGGGTCTGAGGTAAAACCCGAA 1051 1100 ACTTAATTTCTTTCAAAAATTTAAAGTTGCATTTATTATTTTATATGTGT 1101 1150 GCCCATATGTGTGCCACAGTGTCTATGTGGAGGTCAGAGGGCAAGTTGTG 1151 1200 GGCATTGGCTCTCTCCTTTCATAATGTGGCTTCTGGGGACCAAAATGTCA 1201 1250 GGCATGGTGGCAAGAGCTTTTACCTGTTGAGCCATCTCATGGTTTCGTAA 1251 1300 AACTTCCTATGACGCTTACAGGTAACGCAGAGACACAGACTCACATTTGG 1301 1350 AGTTAGCAGATGCTGTATTGGTGTAAACACTCATACACAGACACACACAC 1351" 1400 ATACTCATACACACACACACACACTTATCACATGCACACACATACTCGTA 1401 1450 TACACACAGACACACACACATGCACTCTCACATTCACATATTCATACACA 1451 1500 TCCACACACACACTCATCCACACACACAGACACACATACTCATCCACACA 1501 1550 CACACACACACATACTCATACACACACACAGACACACATACTCATACACA 1551 1600 CACACAGACACACACATATAATCATACATACACAGACACACTCATACATG 1601 1650 TGCACACACACACTCATCCACACACACACACTCATACACACACACACTCA 1651 1700 TACACACACACACTCATACACACACACACGAGGTTTTTCTCAGGCTGCCT 1701 1750 TTGGGTGGAGACTGGAACTGATTTCTGTTTTTCAGCTCCTTGGCTTTTTG 1751 1800 TCCCTTTAGATGAGATCTCCTCCTCACTTTACACACAGAAAGATCACACA 1801 1850 CGAGGGAGAACTGGCGGTGCGGAAGAGGGCTACACGGTAGGGTGTCAGGG 1851 1900 TCAGGAGATCTTCCTGGCAAGTCTCAAACCTCCACATAGCACAGTGTTTA 1901 1950 CGTGAGGATTTAGGAGGAATCAGGAAGAGGATTGGTTTACTGCAGAGCAG 1951 2000 ACCATATAGGTCCACTCCTAAGCCCCATTTGAAATTAGAAGTGAGACAGT 2001 2050 GTGGGATAAAAAGAGCAGATCTCTGGTCACATTTTTAAAGGGATATGAGG 2051 3000 GTCCTGTGCCTTTAAGCCTTCCCATCTCCCTCCAATCCCCCCTCACCTTC 2101 2150 CCCACCCTAACCCTCCCCAGGTTTCTGGAGGAGCAGAGTTGCGTCTTCTC 2151 2200 CCTGCCCTGCCGAGCTGCTCACTGGCTGCTCTAGAGGCTGTGCTTTGCGG 2201 2250 TCTCCATGGAAACCATTAGTTGCTAAGCAACTGGAGCATCATCTGTGCTG 2251 2300 AGCTCAGGTCCTATCGAGTTCACCTAGCTGAGACACCCACGCCCCTGCAG 2301 2350 CCACTTTGCAGTGACAAGCCTGAGTCTCAGGTTCTGCATCTATAAAAACG 2351 2400 AGTAGCCTTTCAGGAGGGCATGCAGAGCCCCCTGGCCAGCGTCTAGAGGA 2401 2450 GAGGTGACTGAGTGGGGCCATGTCACTCGTCCATGGCTGGAGAACCTCCA 2451 2500 TCAGTCTCCCAGTTAGCCTGGGGCAGGAGAGAACCAGAGGAGCTGTGGCT 2501 2550 GCTGATTGGATGATTTACGTACCCAATCTGTTGTCCCAGGCATCGAACCC 2551 2600 CAGAGCGACCTGCACACATGCCACCGCTGCCCCGCCCTCCACCTCCTCTG 2601 2650 CTCCTGGTTACAGGATTGTTTTGTCTTGAAGGGTTTTGTTGTTGCTACTT 2651 2700 TTTGCTTTGTTTTTTCTTTTTTAACATAAGGTTTCTCTGTGTAGCCCTAG 2701 2750 CTGTCCTGGAACTCACTCTGTAGACCAGGCTGGCCTCAAACTCAGAAATC 2751 2800 CACCTTCCTCCCAAGTGCT ' GGGATTAAAGGCATTCGCACCATCGCCCAGC 2801 2850 CCCCGGTCTTGTTTCCTAAGGTTTTCCTGCTTTACTCGCTACCCGTTGCA 2851 2900 CAACCGCTTGCTGTCCAAGTCTGTTTGTATCTACTCCACCGCCCACTAGC 2901 2950 CTTGCTGGACTGGACCTACGTTTACCTGGAAGCCTTCACTAACTTCCCTT 2951 3000 GTCTCCACCTTCTGGAGAAATCTGAAGGCTCACACTGATACCCTCCGCTT 3001 3050 CTCCCAGAGTCGCAGTTTCTTAGGCCTCAGTTAAATACCAGAATTGGATC 3051 3100 TCAGGCTCTGCTATCCCCACCCTACCTAACCAACCCCCTCCTCTCCCATC 3101 3150 CTTACTAGCCAAAGCCCTTTCAACCCTTGGGGCTTTTCCTACACCTACAC 3151 3200 ACCAGGGCAATTTTAGAACTCATGGCTCTCCTAGAAAACGCCTACCTCCT 3201 3250 TGGAGACTGACCCTCTACAGTCCAGGAGGCAGACACTCAGACAGAGGAAC 3251 3300 TCTGTCCTTCAGTCGCGGGAGTTCCAGAAAGAGCCATACTCCCCTGCAGA 3301 3350 GCTAACTAAGCTGCCAGGACCCAGCCAGAGCATCCCCCTTTAGCCGAGGG 3351 3400 CCAGCTCCCCAGAATGAAAAACCTGTCTGGGGCCCCTCCCTGAGGCTACA 3401 3450 GTCGCCAAGGGGCAAGTTGGACTGGATTCCCAGCAGCCCCTCCCACTCCG 3451 3500 AGACAAAATCAGCTACCCTGGGGCAGGCCTCATTGGCCCCAGGAAACCCC 3501 3550 AGCCTGTCAGCACCTGTTCCAGGATCCAGTCCCAGCGCAGTA 3551 3592 AFP-TRE. SEQ IDNO:8. 1 GCATTGCTGTGAACTCTGTACTTAGGACTAAACTTTGAGCAATAACACACATAGATTGAG 61 GATTGTTTGCTGTTAGCATACAAACTCTGGTTCAAAGCTCCTCTTTATTGCTTGTCTTGG 121 AAAA.TTTGCTGTTCTTCATGGTTTCTCTTTTCACTGCTATCTATTTTTCTCAACCACTCA 181 CATGGCTACAATAACTGTCTGCAAGCTTATGATTCCCAAATATCTATCTCTAGCCTCAAT 241 CTTGTTCCAGAAGATAAAΆAGTAGTATTCAAATGCACATCAACGTCTCCACTTGGAGGGC 301 TTAAAGACGTTTCAΆCATACAAACCGGGGAGTTTTGCCTGGAΆTGTTTCCTAAAATGTGT 361 CCTGTAGCACATAGGGTCCTCTTGTTCCTTAAAATCTAATTACTTTTAGCCCAGTGCTCA 421 TCCCACCTATGGGGAGATGAGAGTGAAAAGGGAGCCTGATTAATAATTACACTAAGTCAA 481 TAGGCATAGAGCCAGGACTGTTTGGGTAAACTGGTCACTTTATCTTAAACTAAATATATC 541 CAAAACTGAACATGTACTTAGTTACTAAGTCTTTGACTTTATCTCATTCATACCACTCAG 601 CTTTATCCAGGCCACTTATGAGCTCTGTGTCCTTGAACATAAΆATACAAATAACCGCTAT 661 GCTGTTAATTATTGGCAAATGTCCCATTTTCAACCTAAGGAAATACCATAAAGTAΆCAGA 721 TATACCAACAAAAGGTTACTAGTTAACAGGCATTGCCTGAAAAGAGTATAAAAGAATTTC 781 AGCATGATTTTCCATATTGTGCTTCCACCACTGCCAATAACA (822) Probasin-TRE SEQ ID NO:9 -426 5' -AAGCTTCCACAAGTGCATTTAGCCTCTCCAGTATTGCTGATGAATCCACAGT TCAGGTTCAATGGCGTTCA&AACTTGATCAAAAATGACCAGACTTTATATTTA CACCAACATCTATCTGATTGGAGGAATGGATAATAGTCATCATGTTTAAACAT CTACCATTCCAGTTAAGAAAATATGATAGCATCTTGTTCTTAGTCTTTTTCTTA ARE-1 ATAGGGACATAAAGCCCACAAATAAAAATATGCCTGAAGAATGGGACAGGC ATTGGGCATTGTCCATGCCTAGTAAAGTACTCCAAGAACCTATTTGTATACTA ARE-2 GATGACACAATGTCAATGTCTGTGTACAACTGCCAACTGGGATGCAAGACAC TGCCCATGCCAATCATCCTGAAAAGCAGCTATAAAAAGCAGGAAGCTACTCT CAAT box TATAA box +1 +28 GCACCTTGTCAGTAGGTCCAGATACCTACAG-3 ' Transcription site Tyrosinase-TRE. SEQ ID NO: 10 PinAl end , ΛeJ , 1 CCGG-tJGAAAATGATAAGTTGAATTCTGTCTTCGAGAACATAGAAAAGAA 5l TTATGAAATGCCA&CATGTGGTTACAAGTAATGCAGACCCAAGGCTCCCC 101 AGGGACAAGAAGTCTTGTGTTAACTCTTTGTGGCTCTGAAAGAAAGAGAG 301 GGTGAATAGAGTTTTTCACTTTAACATAGGCCTATCCCACTGGTGGGATA 351 CGAGCCAATTCGAAAGAAAAAGTCAGTCATGTGCTTTTCAGAGGATGAA - I 401 GCTTAAGATAAAGACTAAAAGTGTTTGATGCTGGAGGTGGGAGTGGTATT 451 ATATAGGTCTCAGCCAAGACATGTGATAATCACTGTAGTAGTAGCTGGAA 501 AGAGAAATCTGTGACTCCAATTAGCCAGTTCCTGCAGACCTTGTGA PinAl end Human glandular kallikrein-TRE SEQ ID NO:l 1 gaattcagaa ataggggaag gttgaggaag gacactgaac tcaaagggga tacagtgatt 60 ggtttatttg tcttctcttc acaacattgg tgctggagga attcccaccc tgaggttatg 120 aagatgtctg aacacccaac acatagcact ggagatatga gctcgacaag agtttctcag 180 ccacagagat tcacagccta gggcaggagg acactgtacg ccaggcagaa tgacatggga 240 attgcgctca cgattggctt gaagaagcaa ggactgtggg aggtgggctt tgtagtaaca 300 agagggcagg gtgaactctg attcccatgg gggaatgtga tggtcctgtt acaaattttt 360 caagctggca gggaataaaa cccattacgg tgaggacctg tggagggcgg ctgccccaac 420 tgataaagga aatagccagg tgggggcctt tcccattgta ggggggacat atctggcaat 480 agaagccttt gagacccttt agggtacaag tactgaggca gcaaataaaa tgaaatctta 540 tttttcaact ttatactgca tgggtgtgaa gatatatttg tttctgtaca gggggtgagg 600 gaaaggaggg gaggaggaaa gttcctgcag gtctggtttg gtcttgtgat ccagggggtc 660 ttggaactat ttaaattaaa ttaaattaaa acaagcgact gttttaaatt aaattaaatt 720 aaattaaatt ttactttatt ttatcttaag ttctgggcta catgtgcagg acgtgcagct 780 ttgttacata ggtaaacgtg tgccatggtg gtttgctgta cctatcaacc catcacctag 840 gtattaagcc cagcatgcat tagctgtttt tcctgacgct ctccctctcc ctgactccca 900 caacaggccc cagtgtgtgt tgttcccctc cctgtgtcca tgtgttctca ttgttcagct 960 cccacttata agtgagaaca tgtggtgttt ggttttctgt ttctgtgtta gtttgctgag 1020 gataatggct tccacctcca tccatgttcc tgcaaaggac gtgatcttat tcttttttat 1080 ggttgcatag aaattgtttt tacaaatcca attgatattg tatttaatta caagttaatc 1140 taattagcat actagaagag attacagaag atattaggta cattgaatga ggaaatatat 1200 aaaataggac gaaggtgaaa tattaggtag gaaaagtata atagttgaaa gaagtaaaaa 1260 aaaatatgca tgagtagcag aatgtaaaag aggtgaagaa cgtaatagtg actttttaga 1320 ccagattgaa ggacagagac agaaaaattt taaggaattg ctaaaccatg tgagtgttag 1380 aagtacagtc aataacatta aagcctcagg aggagaaaag aataggaaag gaggaaatat 1440 gtgaataaat agtagagaca tgtttgatgg attttaaaat atttgaaaga cctcacatca 1500 aaggattcat accgtgccat tgaagaggaa gatggaaaag ccaagaagcc agatgaaagt 1560 tagaaatatt attggcaaag cttaaatgtt aaaagtccta gagagaaagg atggcagaaa 1620 tattggcggg aaagaatgca gaacctagaa tataaattca tcccaacagt ttggtagtgt 1680 gcagctgtag ccttttctag ataatacact attgtcatac atcgcttaag cgagtgtaaa 1740 atggtctcct cactttattt atttatatat ttatttagtt ttgagatgga gcctcgctct 1800 gtctcctagg ctggagtgca atagtgcgat accactcact gcaacctctg cctcctctgt 1860 tcaagtgatt ttcttacctc agcctcccga gtagctggga ttacaggtgc gtgccaccac 1920 acccggctaa tttttgtatt ttttgtagag acggggtttt gccatgttgg ccaggctggt 1980 cttgaactcc tgacatcagg tgatccacct gccttggcct cctaaagtgc tgggattaca 2040 ggcatgagcc accgtgccca accactttat ttatttttta tttttatttt taaatttcag 2100 cttctatttg aaatacaggg ggcacatata taggattgtt acatgggtat attgaactca 2160 ggtagtgatc atactaccca acaggtaggt tttcaaccca ctccccctct tttcctcccc 2220 attctagtag tgtgcagtgt ctattgttct catgtttatg tctatgtgtg ctccaggttt 2280 agctcccacc tgtaagtgag aacgtgtggt atttgatttt ctgtccctgt gttaattcac 2340 ttaggattat ggcttccagc tccattcata ttgctgtaaa ggatatgatt catttttcat 2400 ggccatgcag tattccatat tgcgtataga tcacattttc tttctttttt ttttttgaga 2460 cggagtcttg ctttgctgcc taggctggag tgcagtagca cgatctcggc tcactgcaag 2520 cttcacctcc ggggttcacg tcattcttct gtctcagctt cccaagtagc tgggactaca 2580 ggcgcccgcc accacgtccg gctaattttt ttgtgtgttt ttagtagaga tgggggtttc 2640 actgtgttag ccaggatggt cttgatctcc tgaccttgtg gtccacctgc ctcggtctcc 2700 caaagtgctg ggattacagg ggtgagccac tgcgcccggc ccatatatac cacattttct 2760 ttaaccaatc caccattgat gggcaactag gtagattcca tggattccac agttttgcta 2820 ttgtgtgcag tgtggcagta gacatatgaa tgaatgtgtc tttttggtat aatgatttgc 2880 attcctttgg gtatacagtc attaatagga gtgctgggtt gaacggtggc tctgtttaaa 2940 attctttgag aattttccaa actgtttgcc atagagagca aactaattta catttccacg 3000 aacagtatat aagcattccc ttttctccac agctttgtca tcatggtttt tttttttctt 3060 tattttaaaa aagaatatgt tgttgttttc ccagggtaca tgtgcaggat gtgcaggttt 3120 gttacatagg tagtaaacgt gagccatggt ggtttgctgc acctgtcaac ccattacctg 3180 ggtatgaagc cctgcctgca ttagctcttt tccctaatgc tctcactact gccccaccct 3240 caccctgaca gggcaaacag acaacctaca gaatgggagg aaatttttgc aatctattca 3300 tctgacaaag gtcaagaata tccagaatct acaaggaact taagcaaatt tttacttttt 3360 aataatagcc actctgactg gcgtgaaatg gtatctcatt gtggttttca tttgaatttc 3420 tctgatgatc agtgacgatg agcatttttt catatttgtt ggctgcttgt acgtcttttg 3480 agaagtgtct cttcatgcct tttggccact ttaatgggat tattttttgc tttttagttt 3540 aagttcctta tagattctgg atattagact tcttattgga tgcatagttt gtgaatactc 3600 tcttccattc tgtaggttgt ctgtttactc tattgatggc ttcttttgct gtgccgaagc 3660 atcttagttt aattagaaac cacctgccaa tttttgtttt tgttgcaatt gcttttgggg 3720 acttagtcat aaactctttg ccaaggtctg ggtcaagaag agtatttcct aggttttctt 3780 ctagaatttt gaaagtctga atgtaaacat ttgcattttt aatgcatctt gagttagttt 3840 ttgtatatgt gaaaggtcta ctctcatttt ctttccctct ttctttcttt ctttcttttc 3900 tttctttctt tctttctttc tttctttctt tctttctttc tttctttttg tccttctttc 3960 tttctttctt tctctttctt tctctctttc tttttttttt ttgatggagt attgctctgt 4020 tgcccaggct gcagtgcagc ggcacgatct cggctcactg caacctctgc ctcctgggtt 4080 caactgattc tcctgcatca gccttccaag tagctgggat tataggcgcc cgccaccacg 4140 cccgactaat ttttgtattt ttagtagaga cggggttgtg ccatgttggc caggctggtt 4200 tgaaactcct gacctcaaac gatctgcctg ccttggcctc ccaaagtgct gggattacag 4260 gtgtgagcca ctgtgcccag ccaagaatgt cattttctaa gaggtccaag aacctcaaga 4320 tattttggga ccttgagaag agaggaattc atacaggtat tacaagcaca gcctaatggc 4380 aaatctttgg catggcttgg cttcaagact ttaggctctt aaaagtcgaa tccaaaaatt 4440 tttataaaag ctccagctaa gctaccttaa aaggggcctg tatggctgat cactcttctt 4500 gctatacttt acacaaataa acaggccaaa tataatgagg ccaaaattta ttttgcaaat 4560 aaattggtcc tgctatgatt tactcttggt aagaacaggg aaaatagaga aaaatttaga 4620 ttgcatctga cctttttttc tgaattttta tatgtgccta caatttgagc taaatcctga 4680 attattttct ggttgcaaaa actctctaaa gaagaacttg gttttcattg tcttcgtgac 4740 acatttatct ggctctttac tagaacagct ttcttgtttt tggtgttcta gcttgtgtgc 4800 cttacagttc tactcttcaa attattgtta tgtgtatctc atagttttcc ttcttttgag 4860 aaaactgaag ccatggtatt ctgaggacta gagatgactc aacagagctg gtgaatctcc 4920 tcatatgcaa tccactgggc tcgatctgct tcaaattgct gatgcactgc tgctaaagct 4980 atacatttaa aaccctcact aaaggatcag ggaccatcat ggaagaggag gaaacatgaa 5040 attgtaagag ccagattcgg ggggtagagt gtggaggtca gagcaactcc accttgaata 5100 agaaggtaaa gcaacctatc ctgaaagcta acctgccatg gtggcttctg attaacctct 5160 gttctaggaa gactgacagt ttgggtctgt gtcattgccc aaatctcatg ttaaattgta 5220 atccccagtg ttcggaggtg ggacttggtg gtaggtgatt cggtcatggg agtagatttt 5280 cttctttgtg gtgttacagt gatagtgagt gagttctcgt gagatctggt catttaaaag 5340 tgtgtggccc ctcccctccc tctcttggtc ctcctactgc catgtaagat acctgctcct 5400 gctttgcctt ctaccataag taaaagcccc ctgaggcctc cccagaagca gatgccacca 5460 tgcttcctgt acagcctgca gaaccatcag ccaattaaac ctcttttctg tataaattac 5520 cagtcttgag tatctcttta cagcagtgtg agaacggact aatacaaggg tctccaaaat 5580 tccaagttta tgtattcttt cttgccaaat agcaggtatt taccataaat cctgtcctta 5640 ggtcaaacaa ccttgatggc atcgtacttc aattgtctta cacattcctt ctgaatgact 5700 cctcccctat ggcatataag ccctgggtct tgggggataa tggcagaggg gtccaccatc 5760 ttgtctggct gccacctgag acacggacat ggcttctgtt ggtaagtctc tattaaatgt 5820 ttctttctaa gaaactggat ttgtcagctt gtttctttgg cctctcagct tcctcagact 5880 ttggggtagg ttgcacaacc ctgcccacca cgaaacaaat gtttaatatg ataaatatgg 5940 atagatataa tccacataaa taaaagctct tggagggccc tcaataattg ttaagagtgt 6000 aaatgtgtcc aaagatggaa aatgtttgag aactactgtc ccagagattt tcctgagttc 6060 tagagtgtgg gaatatagaa cctggagctt ggcttcttca gcctagaatc aggagtatgg 6120 ggctgaagtc tgaagcttgg cttcagcagt ttggggttgg cttccggagc acatatttga 6180 catgttgcga ctgtgatttg gggtttggta tttgctctga atcctaatgt ctgtccttga 6240 ggcatctaga atctgaaatc tgtggtcaga attctattat cttgagtagg acatctccag 6300 tcctggttct gccttctagg gctggagtct gtagtcagtg acccggtctg gcatttcaac 6360 ttcatataca gtgggctatc ttttggtcca tgtttcaacc aaacaaccga ataaaccatt 6420 agaacctttc cccacttccc tagctgcaat gttaaaccta ggatttctgt ttaataggtt 6480 catatgaata atttcagcct gatccaactt tacattcctt ctaccgttat tctacaccca 6540 ccttaaaaat gcattcccaa tatattccct ggattctacc tatatatggt aatcctggct 6600 ttgccagttt ctagtgcatt aacatacctg atttacattc ttttacttta aagtggaaat 6660 aagagtccct ctgcagagtt caggagttct caagatggcc cttacttctg acatcaattg 6720 agatttcaag ggagtcgcca agatcatcct caggttcagt gattgctggt agccctcata 6780 taactcaatg aaagctgtta tgctcatggc tatggtttat tacagcaaaa gaatagagat 6840 gaaaatctag caagggaaga gttgcatggg gcaaagacaa ggagagctcc aagtgcagag 6900 attcctgttg ttttctccca gtggtgtcat ggaaagcagt atcttctcca tacaatgatg 6960 tgtgataata ttcagtgtat tgccaatcag ggaactcaac tgagccttga ttatattgga 7020 gcttggttgc acagacatgt cgaccacctt catggctgaa ctttagtact tagcccctcc 7080 agacgtctac agctgatagg ctgtaaccca acattgtcac cataaatcac attgttagac 7140 tatccagtgt ggcccaagct cccgtgtaaa cacaggcact ctaaacaggc aggatatttc 7200 aaaagcttag agatgacctc ccaggagctg aatgcaaaga cctggcctct ttgggcaagg 7260 agaatccttt accgcacact ctccttcaca gggttattgt gaggatcaaa tgtggtcatg 7320 tgtgtgagac accagcacat gtctggctgt ggagagtgac ttctatgtgt gctaacattg 7380 ctgagtgcta agaaagtatt aggcatggct ttcagcactc acagatgctc atctaatcct 7440 cacaacatgg ctacagggtg ggcactacta gcctcatttg acagaggaaa ggactgtgga 7500 taagaagggg gtgaccaata ggtcagagtc attctggatg caaggggctc cagaggacca 7560 tgattagaca ttgtctgcag agaaattatg gctggatgtc tctgccccgg aaagggggat 7620 gcactttcct tgacccccta tctcagatct tgactttgag gttatctcag acttcctcta 7680 tgataccagg agcccatcat aatctctctg tgtcctctcc ccttcctcag tcttactgcc 7740 cactcttccc agctccatct ccagctggcc aggtgtagcc acagtaccta actctttgca 7800 gagaactata aatgtgtatc ctacagggga gaaaaaaaaa aagaactctg aaagagctga 7860 cattttaccg acttgcaaac acataagcta acctgccagt tttgtgctgg tagaactcat 7920 gagactcctg ggtcagaggc aaaagatttt attacccaca gctaaggagg cagcatgaac 7980 tttgtgttca catttgttca ctttgccccc caattcatat gggatgatca gagcagttca 8040 ggtggatgga cacaggggtt tgtggcaaag gtgagcaacc taggcttaga aatcctcaat 8100 cttataagaa ggtactagca aacttgtcca gtctttgtat ctgacggaga tattatcttt 8160 ataattgggt tgaaagcaga cctactctgg aggaacatat tgtatttatt gtcctgaaca 8220 gtaaacaaat ctgctgtaaa atagacgtta actttattat ctaaggcagt aagcaaacct 8280 agatctgaag gcgataccat cttgcaaggc tatctgctgt acaaatatgc ttgaaaagat 8340 ggtccagaaa agaaaacggt attattgcct ttgctcagaa gacacacaga aacataagag 8400 aaccatggaa aattgtctcc caacactgtt cacccagagc cttccactct tgtctgcagg 8460 acagtcttaa catcccatca ttagtgtgtc taccacatct ggcttcaccg tgcctaacca 8520 agatttctag gtccagttcc ccaccatgtt tggcagtgcc ccactgccaa ccccagaata 8580 agggagtgct cagaattccg aggggacatg ggtggggatc agaacttctg ggcttgagtg 8640 cagagggggc ccatactcct tggttccgaa ggaggaagag gctggaggtg aatgtccttg 8700 gaggggagga atgtgggttc tgaactctta aatccccaag ggaggagact ggtaaggtcc 8760 cagcttccga ggtactgacg tgggaatggc ctgagaggtc taagaatccc gtatcctcgg 8820 gaaggagggg ctgaaattgt gaggggttga gttgcagggg tttgttagct tgagactcct 8880 tggtgggtcc ctgggaagca aggactggaa ccattggctc cagggtttgg tgtgaaggta 8940 atgggatctc ctgattctca aagggtcaga ggactgagag ttgcccatgc tttgatcttt 9000 ccatctactc cttactccac ttgagggtaa tcacctactc ttctagttcc acaagagtgc 9060 gcctgcgcga gtataatctg cacatgtgcc atgtcccgag gcctggggca tcatccactc 9120 atcattcagc atctgcgcta tgcgggcgag gccggcgcca tgacgtcatg tagctgcgac 9180 tatccctgca gcgcgcctct cccgtcacgt cccaaccatg gagctgtgga cgtgcgtccc 9240 ctggtggatg tggcctgcgt ggtgccaggc cggggcctgg tgtccgataa agatcctaga 9300 accacaggaa accaggactg aaaggtgcta gagaatggcc atatgtcgct gtccatgaaa 9360 tctcaaggac ttctgggtgg agggcacagg agcctgaact tacgggtttg ccccagtcca 9420 ctgtcctccc aagtgagtct cccagatacg aggcactgtg ccagcatcag cttcatctgt 9480 accacatctt gtaacaggga ctacccagga ccctgatgaa caccatggtg tgtgcaggaa 9540 gagggggtga aggcatggac tcctgtgtgg tcagagccca gagggggcca tgacgggtgg 9600 ggaggaggct gtggactggc tcgagaagtg ggatgtggtt gtgtttgatt tcctttggcc 9660 agataaagtg ctggatatag cattgaaaac ggagtatgaa gaccagttag aatggagggt 9720 caggttggag ttgagttaca gatggggtaa aattctgctt cggatgagtt tggggattgg 9780 caatctaaag gtggtttggg atggcatggc tttgggatgg aaataggttt gtttttatgt 9840 tggctgggaa gggtgtgggg attgaattgg ggatgaagta ggtttagttt tggagataga 9900 atacatggag ctggctattg catgcgagga tgtgcattag tttggtttga tctttaaata 9960 aaggaggcta ttagggttgt cttgaattag attaagttgt gttgggttga tgggttgggc 10020 ttgtgggtga tgtggttgga ttgggctgtg ttaaattggt ttgggtcagg ttttggttga 10080 ggttatcatg gggatgagga tatgcttggg acatggattc aggtggttct cattcaagct 10140 gaggcaaatt tcctttcaga cggtcattcc agggaacgag tggttgtgtg ggggaaatca 10200 ggccactggc tgtgaatatc cctctatcct ggtcttgaat tgtgattatc tatgtccatt 10260 ctgtctcctt cactgtactt ggaattgatc tggtcattca gctggaaatg ggggaagatt 10320 ttgtcaaatt cttgagacac agctgggtct ggatcagcgt aagccttcct tctggtttta 10380 ttgaacagat gaaatcacat tttttttttc aaaatcacag aaatcttata gagttaacag 10440 tggactctta taataagagt taacaccagg actcttattc ttgattcttt tctgagacac 10500 caaaatgaga tttctcaatg ccaccctaat tctttttttt tttttttttt tttttgagac 10560 acagtctggg tcttttgctc tgtcactcag gctggagcgc agtggtgtga tcatagctca 10620 ctgaaccctt gacctcctgg acttaaggga tcctcctgct tcagcctcct gagtagatgg 10680 ggctacaggt gcttgccacc acacctggct aattaaattt tttttttttt tttgtagaga 10740 aagggtctca ctttgttgcc ctggctgatc ttgaacttct gacttcaagt gattcttcag 10800 ccttggactc ccaaagcact gggattgctg gcatgagcca ctcaccgtgc ctggcttgca 10860 - gcttaatctt ggagtgtata aacctggctc ctgatagcta gacatttcag tgagaaggag 10920 gcattggatt ttgcatgagg acaattctga cctaggaggg caggtcaaca ggaatccccg 10980 ctgtacctgt acgttgtaca ggcatggaga atgaggagtg aggaggccgt accggaaccc 11040 catattgttt agtggacatt ggattttgaa ataataggga acttggtctg ggagagtcat 11100 atttctggat tggacaatat gtggtatcac aaggttttat gatgagggag aaatgtatgt 11160 ggggaaccat tttctgagtg tggaagtgca agaatcagag agtagctgaa tgccaacgct 11220 tctatttcag gaacatggta agttggaggt ccagctctcg ggctcagacg ggtataggga 11280 ccaggaagtc tcacaatccg atcattctga tatttcaggg catattaggt ttggggtgca 11340 aaggaagtac ttgggactta ggcacatgag actttgtatt gaaaatcaat gattggggct 11400 ggccgtggtg ctcacgcctg taatctcatc actttgggag accgaagtgg gaggatggct 11460 tgatctcaag agttggacac cagcctaggc aacatggcca gaccctctct ctacaaaaaa 11520 attaaaaatt agctggatgt ggtggtgcat gcttgtggtc tcagctatcc tggaggctga 11580 gacaggagaa tcggttgagt ctgggagttc aaggctacag ggagctgcga tcacgccgct 11640 gcactccagc ctgggaaaca gagtgagact gtctcagaat ttttttaaaa aagaatcagt 11700 gatcatccca acccctgttg ctgttcatcc tgagcctgcc ttctctggct ttgttcccta 11760 gatcacatct ccatgatcca taggccctgc ccaatctgac ctcacaccgt gggaatgcct 11820 ccagactgat ctagtatgtg tggaacagca agtgctggct ctccctcccc ttccacagct 11880 ctgggtgtgg gagggggttg tccagcctcc agcagcatgg ggagggcctt ggtcagcatc 11940 taggtgccaa cagggcaagg gcggggtcct ggagaatgaa ggctttatag ggctcctcag 12000 ggaggccccc cagccccaaa ctgcaccacc tggccgtgga caccggt 12047 HRE-TRE SEQ ID NO: 12 ccccgagg cagtgcat gaggctcagg gcgtgcgt gagtcgcagcgagaccccg gggtgcag gccgga PSA-TRE SEQ ID NO:13 aagcttctag ttttcttttc ccggtgacat cgtggaaagc actagcatct ctaagcaatg 60 atctgtgaca atattcacag tgtaatgcca tccagggaac tcaactgagc cttgatgtcc 120 agagattttt gtgttttttt ctgagactga gtctcgctct gtgccaggct ggagtgcagt 180 ggtgcaacct tggctcactg caagctccgc ctcctgggtt cacgccattc tcctgcctca 240 gcctcctgag tagctgggac tacaggcacc cgccaccacg cctggctaat ttttttgtat 300 ttttagtaga gatggggttt cactgtgtta gccaggatgg tctcagtctc ctgacctcgt 360 gatctgccca ccttggcctc ccaaagtgct gggatgacag gcgtgagcca ccgcgcctgg 420 ccgatatcca gagatttttt ggggggctcc atcacacaga catgttgact gtcttcatgg 480 ttgactttta gtatccagcc cctctagaaa tctagctgat atagtgtggc tcaaaacctt 540 cagcacaaat cacaccgtta gactatctgg tgtggcccaa accttcaggt gaacaaaggg 600 actctaatct ggcaggatac tccaaagcat tagagatgac ctcttgcaaa gaaaaagaaa 660 tggaaaagaa aaagaaagaa aggaaaaaaa aaaaaaaaaa gagatgacct ctcaggctct 720 gaggggaaac gcctgaggtc tttgagcaag gtcagtcctc tgttgcacag tctccctcac 780 agggtcattg tgacgatcaa atgtggtcac gtgtatgagg caccagcaca tgcctggctc 840 tggggagtgc cgtgtaagtg tatgcttgca ctgctgaatg gctgggatgt gtcagggatt 900 atcttcagca cttacagatg ctcatctcat cctcacagca tcactatggg atgggtatta 960 ctggcctcat ttgatggaga aagtggctgt ggctcagaaa ggggggacca ctagaccagg 1020 gacactctgg atgctgggga ctccagagac catgaccact caccaactgc agagaaatta 1080 attgtggcct gatgtccctg tcctggagag ggtggaggtg gaccttcact aacctcctac 1140 cttgaccctc tcttttaggg ctctttctga cctccaccat ggtactagga ccccattgta 1200 ttctgtaccc tcttgactct atgaccccca ccgcccactg catccagctg ggtcccctcc 1260 tatctctatt cccagctggc cagtgcagtc tcagtgccca cctgtttgtc agtaactctg 1320 aaggggctga cattttactg acttgcaaac aaataagcta actttccaga gttttgtgaa 1380 tgctggcaga gtccatgaga ctcctgagtc agaggcaaag gcttttactg ctcacagctt 1440 agcagacagc atgaggttca tgttcacatt agtacacctt gcccccccca aatcttgtag 1500 ggtgaccaga gcagtctagg tggatgctgt gcagaagggg tttgtgccac tggtgagaaa 1560 cctgagatta ggaatcctca atcttatact gggacaactt gcaaacctgc tcagcctttg 1620 tctctgatga agatattatc ttcatgatct tggattgaaa acagacctac tctggaggaa 1680 catattgtat cgattgtcct tgacagtaaa caaatctgtt gtaagagaca ttatctttat 1740 tatctaggac agtaagcaag cctggatctg agagagatat catcttgcaa ggatgcctgc 1800 tttacaaaca tccttgaaac aacaatccag aaaaaaaaag gtgttactgt ctttgctcag 1860 aagacacaca gatacgtgac agaaccatgg agaattgcct cccaacgctg ttcagccaga 1920 gccttccacc ctttctgcag gacagtctca acgttccacc attaaatact tcttctatca 1980 catcccgctt ctttatgcct aaccaaggtt ctaggtcccg atcgactgtg tctggcagca 2040 ctccactgcc aaacccagaa taaggcagcg ctcaggatcc cgaaggggca tggctgggga 2100 tcagaacttc tgggtttgag tgaggagtgg gtccaccctc ttgaatttca aaggaggaag 2160 aggctggatg tgaaggtact gggggaggga aagtgtcagt tccgaactct taggtcaatg 2220 agggaggaga ctggtaaggt cccagctccc gaggtactga tgtgggaatg gcctaagaat 2280 ctcatatcct caggaagaag gtgctggaat cctgaggggt agagttctgg gtatatttgt 2340 ggcttaaggc tctttggccc ctgaaggcag aggctggaac cattaggtcc agggtttggg 2400 gtgatagtaa tgggatctct tgattcctca agagtctgag gatcgagggt tgcccattct 2460 tccatcttgc cacctaatcc ttactccact tgagggtatc accagccctt ctagctccat 2520 gaaggtcccc tgggcaagca caatctgagc atgaaagatg ccccagaggc cttgggtgtc 2580 atccactcat catccagcat cacactctga gggtgtggcc agcaccatga cgtcatgttg 2640 ctgtgactat ccctgcagcg tgcctctcca gccacctgcc aaccgtagag ctgcccatcc 2700 tcctctggtg ggagtggcct gcatggtgcc aggctgaggc ctagtgtcag acagggagcc 2760 tggaatcata gggatccagg actcaaaagt gctagagaat ggccatatgt caccatccat 2820 gaaatctcaa gggcttctgg gtggagggca cagggacctg aacttatggt ttcccaagtc 2880 tattgctctc ccaagtgagt ctcccagata cgaggcactg tgccagcatc agccttatct 2940 ccaccacatc ttgtaaaagg actacccagg gccctgatga acaccatggt gtgtacagga 3000 gtagggggtg gaggcacgga ctcctgtgag gtcacagcca agggagcatc atcatgggtg 3060 gggaggaggc aatggacagg cttgagaacg gggatgtggt tgtatttggt tttctttggt 3120 tagataaagt gctgggtata ggattgagag tggagtatga agaccagtta ggatggagga 3180 tcagattgga gttgggttag ataaagtgct gggtatagga ttgagagtgg agtatgaaga 3240 ccagttagga tggaggatca gattggagtt gggttagaga tggggtaaaa ttgtgctccg 3300 gatgagtttg ggattgacac tgtggaggtg gtttgggatg gcatggcttt gggatggaaa 3360 tagatttgtt ttgatgttgg ctcagacatc cttggggatt gaactgggga tgaagctggg 3420 tttgattttg gaggtagaag acgtggaagt agctgtcaga tttgacagtg gccatgagtt 3480 ttgtttgatg gggaatcaaa caatggggga agacataagg gttggcttgt taggttaagt 3540 tgcgttgggt tgatggggtc ggggctgtgt ataatgcagt tggattggtt tgtattaaat 3600 tgggttgggt caggttttgg ttgaggatga gttgaggata tgcttgggga caccggatcc 3660 atgaggttct cactggagtg gagacaaact tcctttccag gatgaatcca gggaagcctt 3720 aattcacgtg taggggaggt caggccactg gctaagtata tccttccact ccagctctaa 3780 gatggtctta aattgtgatt atctatatcc acttctgtct ccctcactgt gcttggagtt 3840 tacctgatca ctcaactaga aacaggggaa gattttatca aattcttttt tttttttttt 3900 tttttttgag acagagtctc actctgttgc ccaggctgga gtgcagtggc gcagtctcgg 3960 ctcactgcaa cctctgcctc ccaggttcaa gtgattctcc tgcctcagcc tcctgagttg 4020 ctgggattac aggcatgcag caccatgccc agctaatttt tgtattttta gtagagatgg 4080 ggtttcacca atgtttgcca ggctggcctc gaactcctga cctggtgatc cacctgcctc 4140 agcctcccaa agtgctggga ttacaggcgt cagccaccgc gcccagccac ttttgtcaaa 4200 ttcttgagac acagctcggg ctggatcaag tgagctactc tggttttatt gaacagctga 4260 aataaccaac tttttggaaa ttgatgaaat cttacggagt taacagtgga ggtaccaggg 4320 ctcttaagag ttcccgattc tcttctgaga ctacaaattg tgattttgca tgccacctta 4380 atcttttttt tttttttttt aaatcgaggt ttcagtctca ttctatttcc caggctggag 4440 ttcaatagcg tgatcacagc tcactgtagc cttgaactcc tggccttaag agattctcct 4500 gcttcggtct cccaatagct aagactacag tagtccacca ccatatccag ataattttta 4560 aattttttgg ggggccgggc acagtggctc acgcctgtaa tcccaacacc atgggaggct 4620 gagatgggtg gatcacgagg tcaggagttt gagaccagcc tgaccaacat ggtgaaactc 4680 tgtctctact aaaaaaaaaa aaaatagaaa aattagccgg gcgtggtggc acacggcacc 4740 tgtaatccca gctactgagg aggctgaggc aggagaatca cttgaaccca gaaggcagag 4800 gttgcaatga gccgagattg cgccactgca ctccagcctg ggtgacagag tgagactctg 4860 tctcaaaaaa aaaaaatttt tttttttttt ttgtagagat ggatcttgct ttgtttctct 4920 ggttggcctt gaactcctgg cttcaagtga tcctcctacc ttggcctcgg aaagtgttgg 4980 gattacaggc gtgagccacc atgactgacc tgtcgttaat cttgaggtac ataaacctgg 5040 ctcctaaagg ctaaaggcta aatatttgtt ggagaagggg cattggattt tgcatgagga 5100 tgattctgac ctgggagggc aggtcagcag gcatctctgt tgcacagata gagtgtacag 5160 gtctggagaa caaggagtgg ggggttattg gaattccaca ttgtttgctg cacgttggat 5220 tttgaaatgc tagggaactt tgggagactc atatttctgg gctagaggat ctgtggacca 5280 caagatcttt ttatgatgac agtagcaatg tatctgtgga gctggattct gggttgggag 5340 tgcaaggaaa agaatgtact aaatgccaag acatctattt caggagcatg aggaataaaa 5400 gttctagttt ctggtctcag agtggtgcat ggatcaggga gtctcacaat ctcctgagtg 5460 ctggtgtctt agggcacact gggtcttgga gtgcaaagga tctaggcacg tgaggctttg 5520 tatgaagaat cggggatcgt acccaccccc tgtttctgtt tcatcctggg catgtctcct 5580 ctgcctttgt cccctagatg aagtctccat gagctacaag ggcctggtgc atccagggtg 5640 atctagtaat tgcagaacag caagtgctag ctctccctcc ccttccacag ctctgggtgt 5700 gggagggggt tgtccagcct ccagcagcat ggggagggcc ttggtcagcc tctgggtgcc 5760 agcagggcag gggcggagtc ctggggaatg aaggttttat agggctcctg ggggaggctc 5820 cccagcccca agctt 5835 CEATRESEQ IDNO:14 aagcttttta gtgctttaga cagtgagctg gtctgtctaa cccaagεσac ctgggctcca 60 tactcagccc cagaagtgaa gggtgaagct gggtggagcc aaaccaggca agcctaccct 120 cagggctccc agtggcctga gaaccattgg acccaggacc cattacttct agggtaagga . 180 aggtacaaac accagatcca accatggtct ggggggacag ctgtcaaεtg cctaaaaata 240 tacctgggag aggagcaggc aaactatcac tgccccaggt tctctgaaca gaaacagagg 300 ggcaacccaa agtccaaatc caggtgagca ggtgcaccaa atgcccagag atatgacgag 360 gcaagaagtg aaggaaccac ccctgcatca aatgttttgc atgggaagga gaegggggtt 420 gctcatgttc ccaatccagg agaatgcatt tgggatctgc cttcttctrca ctccttggtt 480 agcaagacta agcaaccagg actctggatt tggggaaaga cgtttatttg tggaggccag 540 tgatgacaat cccacgaggg cc ggtgaa gagggcagga aggctcgaga cactggggac 600 • tgagtgaaaa ccacacccat gatctgcacc acccatggat gctcct cat tgctcacctt 660 tctgttgata tcagatggcc ccattttctg taccttcaca gaaggacaca ggctagggtc 720 tgtgcatggc cttcatcccc ggggccatgt gaggacagca gg gggaaag atcatgggtc 780 ctcctgggtc ctgcagggcc agaacattca tcacccatac tgacctccta gatgggaatg 840 gcttccctgg ggctgggcca acggggcctg ggcaggggag aaaggacgtc aggggacagg 900 gaggaagggt catcgagacc cagcctggaa ggttcttgtc tctgaccatc caggatttac 960 ttccctgcat ctaccttfcgg tcattttccc tcagcaatga ccagctctgc ttcctgatct 1020 cagcctccca ccctggacac agcaccccag tccctggccc ggctgcatcc acccaatacc 1080 ctgataaccc aggacccatt acttctaggg taaggagggt ccaggagaca gaaσctgagg 1140 aaaggtctga agaagtcaca tctgtcctgg ccagagggga aaaaccatca gatgctgaac 1200 caggagaatg ttgacccagg aaagggaccg aggacccaag aaaggagtca gaccaccagg 1260 gtttgcctga gaggaaggat caaggccccg agggaaagca. gggctggctg catgtgcagg 1320 acactggtgg ggcatatgtg tcttagattc tccctgaatt cagtgtccct gccatggcca 1380 gactctctac tcaggcctgg acatgctgaa ataggacaat ggccttgtcc tctctcccca 1440 ccatttggca agagacataa aggacattcc aggacatgcc ttcctgggag gtccaggttc 1500 tctgtctcac acctcaggga ctgtagttac tgcatcagcc atggtaggtg ctgatctcac IS60 ccagcctgtc caggcccttc cactctccac tttgtgacca tgtccaggac cacccctcag 1620 atcctgagcc tgcaaatacc cccttgctgg gtgggtggat tcagtaaaca gtgagctcct 1680 atccagceco-Gagagccacc tctgtcacct tcctgctggg catcatccca ccttcacaag 1740 cactaaagag catggggaga cctggctagc tgggtttctg catcacaaag aaaataatcc 1800 cccaggttcg gattcccagg gctctgtatg tggagctgac agacctgagg ccaggagata 1860 gcagaggtca gccctaggga gggtgggtca tccacccag'g ggacaggggt gcaccagcct' 1920 ' tgctactgaa agggcctccc caggacagcg ccatcagccc tgcctgagag ctttgctaaa 1980 cagcagtcag aggaggccat ggcagtggct gagctcctgc tccaggcccc aacagaccag 2040 accaacagca caatgcagtc cttccccaac gtcacaggtc accaaaggga aactgaggtg 2100 ctacctaacc ttagagccat caggggagat aacagcccaa tttcccaaac. aggccagttt 2160 caatcccatg acaatgacct ctctgctctc attcttccca aaataggacg ctgattctcc 2220 cccaccatgg atttctccct tgtcccggga gccttttctg ccccctatga "tctgggcact 2280 cctgacacac acctcctctc tggtgacata tcagggtccc tcactgtcaa gcagtccaga 2340 aaggacagaa cc tggacag cgcccatctc agcttcaccc ttcσtccttc acagggttca 2400 gggcaaagaa taaatggcag aggccagtga gcccagagat ggtgacaggc agtgacccag 2460 gggcagatgc ctggagcagg agctggcggg gccacaggga gaaggtgatg caggaaggga 2520 aacccagaaa tgggcaggaa aggaggacac aggctctgtg gggctgcagc ccagggttgg 2580 actεtgagtg tgaagccatc tcagcaagta aggccaggtc ccatgaεcaa gagtgggagc 2640 ecgtggcttc ctgctctgta tatggggtgg gggattccat gccccataga accagatggc 2700 cggggttcag atggagaagg agcaggacag gggatcccca ggafcaggagg accccagtgt 2760 ccccacccag gcaggtgact gatgaatggg catgcagggt cctcctgggc tgggctctcc 2820 ctttgtccct caggattcct tgaaggaaca tccggaagcc gaccacatc ' t acctggtggg 2880 ttctggggag tccatgtaaa gccaggagct tgtgttgcta ggaggggtca tggcatgtgc 29 ΪO tgggggcacc aaagagagaa acctgagggc aggcaggacc tggtctgagg aggcatggga .3000 gcccagatgg ggagatggat gtcaggaaag gctgccccat cagggagggt gatagcaatg 3060 ' gggggtctgt gggagtgggc acgtgggatt ccctgggctc tgccaagttc cctcccatag 3120 • tcacaacctg gggacactgc ccatgaaggg gcgcctt ' tgc ccagccagat gctgctggtt 3180 ctgcccatcc actaccctct ctgctccagc cactctgggt ctttctccag atgccctgga 3240 cagccctggc ctgggcctgt cccctgagag gtgttgggag aagctgagtc tctggggaca 3300 ctctcatcag agtctgaaag gcacatcagg aaacafcccct ggtctccagg actaggcaat 3360 gaggaaaggg ccccagctcc tcccttt cc actgagaggg tcgaccctgg gtggccacag 3420 tgacttctgc gtctgtccca gtcaccctga aaccacaaca aaaccccagc cccagaccct 3480 gcaggtacaa tacatgtggg gacag ctgt acccagggga agccagttct ctcttcctag 3540 gagaccgggc ctcagggctg tgcccggσgc aggcgggggc agcacgtgcc tgtccttgag 3600 aactcgggac cttaagggtc tctgctctgt gaggcacagc aaggatcctt ctgtccagag 3660 atgaaagcag ctcctgcccc tcctctgεcc tcttcctcct tcccaaatct caaccaacaa 3720 ataggtgttt caaatctcat catcaaatct tcatccatcc acatgagaaa gcttaaaacc 3780 caatggattg acaacatcaa gagttggaac aagtggacat ggagatgtta cttgtggaaa . 3840 tttagatgtg ttcagctatc gggcaggaga atctgtgtca aattccagca tggttcagaa 3900 gaatcaaaaa gtgtcacagt ccaaatgtgc aacagtgcag gggataaaac tgtggtgcat 3960 tcaaactgag ggatattttg gaacatgaga aaggaaggga ttgctgctgc acagaacatg 4020 gatgatctcε cacatagagt tgaaagaεag gagtcaatcg cagaatagaa aatgatcac ' t 4080 aattccacct ctataaagtt tccaagagga aaacccaatt ctgσtgctag agatcagaat 4140 ggaggtgacc tgtgccttgc aatggctgcg agggtcacgg gagtgtcact tagtgcaggc 4200 aatgtgccgt atcttaatct gggcagggct ttcatgagca cataggaatg cagacattac 4260 tgctgtgttc attttacttc accggaaεεg aagaataaaa tcagccgggc gcggtggctc 4320 acgcctgtaa tcccagcact ttagaagσct gaggtgggca gattacttga ggtcaggagt 4380 tcaagaccac cctggccaat atggtgaεεc ' cccggctcta ctaaaaatac aaaaattagc 4440 tgggcatggt ggtgcgcgcc tgtaatccca gctactcggg aggctgaggc tggacaattg 4500 cttggaccca ggaagcagag gttgcagtga gccaagattg tgccactgca ctccagcttg 4560 ggcaacagag ccagactctg taaaaaaεεa aaaaaaaaaa aaaaaaagaa agaaagaaaa 4620 agaaaagaaa gtataaaatc tctttgggtt aacaaaaaaa gatccacaaa acaaacacca 4680 ■ gctcttatca aacttacaca actctgccεg agaacaggaa acacaaatac tcattaactc 4740 acttttgtgg caataaaacc ttcatgtcεa aaggagacca ggacacaatg aggaagtaaa 4800 actgcaggcc ctacttgggt gcagagaggg aaaatccaca aataaaacat taccagaagg 4860 agctaagatt tactgcattg agttca tcc ccaggtatgc aaggtgattt taacacctga 4920 aaatcaatca ttgcctttac tacatagaca gattagctag aaaaaaatta caactagcag 4980 aacagaagca at tggcctt cctaaaatzc cacatcatat catcatgatg gagacagtgc 5040 agacgccaat gacaataaaa agagggacct ccgtcacccg gtaaacatgt ccacacagct 5100 ccagcaagca-eccgtcttcc cagtgaatca ctctaacctc ccctttaatc agccccaggc 5160 aaggctgcct gcgatggcca cacaggctcc aacccgtggg cctcaacctc ccgcagaggc 5220 tctcctttgg ccaccccatg gggagagcat gaggacaggg cagagccctc tgatgcccac S280 acatggcagg agctgacgcc agagccatgg gggctggaga gcagagctgc tggggtcaga S3 & gcttcctgag gacaccc'agg cctaagggaa ggcagctccc tggatggggg caaccaggct S400 ccgggctcca acctcagagc ccgcatggga ggagccagca ctctaggcct ttcctagggt 5 60 gactctgagg ggaccctgac acgacaggat cgctgaatgc acccgagatg aaggggccac S520 cacgggaccc tgctctcgtg gcagatcagg agεgagtggg acaccatgcc aggcccccat 5580 ggcatggctg cgactgaccc aggccactcc cctgcatgca tcagcctcgg taagtcacat 5640 gaccaagccc aggaccaatg tggaaggaag gaaacagcat cccctttagt gatggaaccc 5700 aaggtcagtg caaagagagg ccatgagcag ttεggaaggg tggtccaacc tacagcacaa 5760 accatcatct atcataagta gaagccctgc tccatgaccc ctgcatttaa ataaacgttt 5820 gttaaatgag tcaaattccc tcaccatgag εgctcacctg tgtgtaggcc catcacacac S880 acaaacacac acacacacac acacacacac εcacacacac acagggaaag tgcaggatcc 59 0 tggacagcac caggcaggct tcacaggcag εgcaaacagc gtgaatgacc catgcagtgc 6000 cctgggcccc atcagctcag agaccctgtg εgggctgaga tggggctagg caggggagag 6060 acttagagag ggtggggcct ccagggaggg ggccgcaggg agctgggtac tgccctccag 6120 ggagggggct gcagggagct gggtactgcc ctccagggag ggggctgcag ggagctgggt 6180 actgccctcc agggaggggg ctgcagggag ctgggtactg ccctccaggg agggggctgc 6240 agggagctgg gtactgccct ccagggaggc εggagcactg ttcccaacag agagcacatc 6300 ttcctgcagc agctgcacag acacaggagc ccccatgact gccctgggcc agggtgtgga 6360 ttccaaattt cgtgccccat tgggtgggap ggεggttgεc cgtgacatcc aaggggcatc 6420 tgtgattcca aacttaaact actgtgccta caaεatagga aataacccta ctttttctac 6480 tatctcaaat tccctaagca caagctagca ccctttaaat caggaagttc agtcactcct 6S40 ggggtcctcc catgccccca gtctgacttg caggtgcaca gggtggctga catctgtcct 6600 tgctcctcct cttggctcaa ctgccgcccc tcctgggggt gactgatggt caggacaagg 6660 gatcctagag ctggccccat gattgacagg aagςcaggac ttggcctcca ttctgaagac 6720 taggggtgtc aagagagctg ggcatcccac agagctgcac aagatgacgc ggacagaggg 6780 tgacacaggg ctcagggctt cagacgggtc gggaggctca gctgagεgtt cagggacaga 6840 cc gaggagc ctcagtggga aaagaagcac tgaagtggga agttctggaa tgttctggac 6900 aagcctgagt gctctaagga aatgctccca ccccgatgta gcctgcagca ctggacggtc 6960 tgtgtacctc cccgctgccc atcctctcac agcccccgcc tctagggaca caactcctgc 7020 cctaacatgc atctttcctg tctcattcca cacaaaaggg cctctggggt ccctgttctg 7080 cattgcaagg agtggaggtc acgttcccac agaccaccca gcaacagggt cctatggagg 7140 tgcggtcagg aggatcacac gtccccccat gcccagggga ctgactctgg gggtgatgga 7200 ttggcctgga ggccactggt cccctctgtc cctgagggga atctgcaccc tggaggctgc 7260 cacatccctc ctgattcttt cagctgaggg cccttcttga aatcccaggg aggactcaac 7320 ccccactggg aaaggcccag tgtggacggt tccacagcag cccagctaag gcccttggac 7380 acagatcctg agtgagagaa cctttaggga cacaggtgca cggccatgtc cccagtgccc 7 40 acacagagca ggggcatctg gaccctgagt gtgtagctcc cgcgactgaa cccεgccctt 7500 ccccaatgac gtgacccctg gggtggctcc aggtctccag tccatgccac caaaatctcc 7560 agattgaggg tcctcccttg agtccctgat gcctgtccag gagctgcccc ctgagcaaat 7620 ctagεgtgca gagggctggg attgtggcag taaaagcagc cacatttgtc tcaggaagga 7680 aagggaggac atgagctcca ggaagggcga tggcgtcctc tagtgggcgc ctcctgttaa 7740 tgagcaaaaa ggggccagga gagttgagag atcagggctg gccttggact aaggctcaga 7800 tggagaggac tgaggtgcaa agagggggct gaagtagggg agtggtcggg agagatggga 7860 ggagcaggta aggggaagcc ccagggaggc cgggggaggg tacagcagag ctctccactc 7920 ctcagcattg acatttgggg tggtcgtgct agtggggttc tgtaagttgt agggtgttca 7980 gcaccatctg gggactctac ccactaaatg ccagcaggac tccctcccca agctctaaca 8040 accaacaatg tctccagact ttccaaatgt cccctggaga gcaaaattgc ttctggcaga 8100 atcactgatc tacgtcagtc tctaaaagtg actcatcagc gaaatccttc acctcttggg 8160 agaagaatca caagtgtgag aggggtagaa actgcagact tcaaaatctt tccaaaagag 8220 ttttacttaa tcagcagttt gatgtcccag gagaagatac atttagagtg tttagagttg 8280 atgccacatg gctgcctgta cctcacagca ggagcagagt gggttttcca agggcctgta 8340 accacaactg gaatgacact cactgggtta cattacaaag tggaatgtgg ggaattctgt 8400 agactttggg aagggaaatg tatgacgtga gcccacagcc taaggcagtg gacagtccac 8460 tttgaggctc tcaccatcta ggagacεtct cagccatgaa catagccaca tctgtcatta 8520 gaaaacatgfc-tttattaaga ggaaaaatct aggctagεag tgcttcatgc tcttttttct 8580 ctttatgttc aaattcatat acttttagat cattccttaa agaaceatct atccccctaa 8640 gtaaatgtta tcactgactg gatagtgttg gtgtctcact cccaacccct gtgtggtgac 8700 agtgccctgc ttccccagcc ctgggccctc tctgattcct gagaσctttg ggtgctcctt 8766- cattaggagg aagagaggaa gggtgttttt aatattctca ccattcaccc atccacctct 8820 tagacactgg gaagaatcag ttgcccactc ttggatttga tcctccaatt aatgacctct 8880 atttctgtcc ' cttgtccatt tcaacaatgt gacaggccta agaggtgcct tctccatgtg 89.40 atttttgagg agaaggttct caagataagt tttctcacac ctctttgaat tacctccacc 9000 tgtgtcccca t caec ttac cagcagcatt tggacccttt ttctgrtagt cagεtgcttt 9060 ccacctcttg agggtgtata ctgtatgctc tctacacεgg aatatgcεga ggaaatagaa 9120 aaagggaaat cgcattacta ttcagagaga agaagacctt tatgtgaatg aatgagagtc 9180 taaaatccta agagagccca tataaaatta ttaccagtgc taaaεctaca aaagttacac 9240 taacagtaaa ctagaataat aaaacatgca tcacagttgc tggtεεagct aaatcagata 9300 tttttttctt agaaaaagca ttccatgtgt gttgcagtga tgacaggεgt gcccttcagt 9360 caatatgctg cctgtaattt ttgttccctg gcagaatgta ttgtcttttc tccctttaaa 9420 tcttaaatgc aaaactaaag gcagctcctg ggccccctcc ccaaagtcag ctgcctgcaa 9480 ccagccccac gaagagcaga ggcctgagct tccctggtca aaatεggggg ctagggagct 9540 taaccttgct cgataaagct gtgttcccag aatgtcgctc ctgttcccag gggcaccagc . 9600 ctggagggtg gtgagcctca ctggtggcct gatgcttεcc ttgtgccctc acaccagtgg 9660 tcactggaac cttgaacact tggctgtcgc ccggatctgc agatgtcaag aacttctgga 9720 agtcaaatta ctgcccactt ctccagggca gatacctgtg aacatccaaa accatgccac 9780 agaaccctgc ctggggtcta caacacatat ggactgtgag caccaεgtcc agccctgaat 9840 ctgtgaccac ctgccaagat gcccctaact gggatccacc aatcactgca catggcaggc 9900 agcgaggctt ggaggtgctt cgccacaagg cagccccaat ttgctgggag tttcttggca 9960 cctggtagtg gtgaggagcc ttgggaccct caggattact ccccttaagc atagtgggga 10020 cccttctgca tccccagcag gtgccccgct cttcagagcc tctctctctg aggtttaccc 10080 agacccctgc accaatgaga ccatgctgaa gcctcagaga gagagatgga gctttgacca 10140 ggagccgctc ttccttgagg gccagggcag ggaaagcagg aggcagcacc aggagtggga 10200 acaccagtg ctaagcccct gatgagaaca gggtggtctc tcccatatgc ccataccagg 10260 cctgtgaaca gaatcctcct tctgcagtga caatgtctga gaggacgaca tgtttcccag 10320 cctaacgtgc agccatgccc atctacccac tgcctactgc aggacagcac caacccagga 10380 gctgggaagc tgggagaaga catggaatac ccatggcttc tcaccttcct ccagtccagt 10440 gggcaccatt tatgcctagg acacccacct gccggcccca ggctcttaag agttaggtca 1050O cctaggtgcc tctgggaggc cgaggcagga gaattgcttg aacccgggag gcagaggttg 10560 cagtgagccg agatcacacc actgcactcc agcctgggtg acagaatgag actctgtctc 10620 aaaaaaaaag agaaagatag catcagtggc taccaagggc taggggcagg ggaaggtgga 10680 gagttaatga ttaatagtat gaagtttcta tgtgagatgε tgaaaεtgtt ctggaaaaaa 10740 aaatatagtg gtgaggatgt agaatattgt gaεtataatt aacggcattt aattgtacac 10800 ttaacatgat taatgtggca tattttatct tatgtatttg actacatcca agaaacactg 10860 ggagagggaa agcccaccat gtaaaataca cccaccctaa tcagatagtc ctcattgtac 10920 ccaggtacag gcccctcatg acctgcacag gaεtaactaa ggatttaagg acatgaggct 10980 tcccagccaa ctgcaggtgc acaacataaa tgtatctgcε aacagactga gagtaaagct 11040 gggggcacaa acctcagcac tgccaggaca cacacccttc tcgtggattc tgactttatc 11100 tgacccggcc cactgtccag atcttgttgt gggattgggε caagggaggt cataaagcct 11160 gtccccaggg cactctgtgt gagcacacga gacctccccε cccccccacc gttaggtctc 11220 cacacataga tctgaccatt aggcattgtg aggaggactc tagcgcgggc tcagggatca 11280 caccagagaa ccaggtacag agaggaagac ggggctcgag gagctgatgg atgacacaga 11340 gcagggttcc tgcagtccac aggtccagct caccctggtg taggtgcccc atccccctga 11400 tccaggcatc cctgacacag ctccctcccg " gagcctcctc ccaggtgaσa catcagggtc 11460 cctcactcaa gctgtccaga gagggcagca ccttggacag cgcccacccc acttcactct 11520 tcctccctca cagggctcag ggctcagggc tcaagtctcε gaacaaatgg cagaggccag 11580 tgagcccaga gatggtgaca gggcaatgat ccaggggcag ctgcctgaaa cgggagcagg 11640 tgaagccaca gatgggagaa gatggttcag gaagaaaaat ccaggaatgg gcaggagagg 11700 agaggaggac acaggctctg tggggctgca gcccaggatg ggactaagtg tgaagacatc 11760 tcagcaggtg aggccaggtc ccatgaacag agaagcagct cccacctccc ctgatgcacg 11820 gacacacaga gtgtgtggtg ctgtgccccc agagtr.gggc tctcctgttc tggtccccag 11880 ggagtgagaa gtgaggttga cttgtccctg ctcctctctg ctaccccaac attcaccttc 11940 1 9 ? tcctcatgcc-cctctctctc aaatatgatt tggatctatg tccccgccca aatctcatgt 12000 caaattgtaa accccaεtgt tggaggtggg gccttgtgag aagtgattgg ataatgcggg 12060 tggattttct gctttgatgc tgtttctgtg atagagatct cacatgatct ggttgtttεa 12120 aagtgtgtag cacctctccc ctctctctct ctctctctta ctcatgctct gccatgtaag 1218U acgttcctgt ttccccttca ccgtccagaa tgattgtaag ttttctgagg cctccccagg 12240 agcagaagcc actatgcttc ctgtacaact gcagaatgat gagcgaatta aacctctttt 12300 ctttataaat tacccagtct caggtatttc tttatagcaa tgcgaggaca gactaataca 12360 atcttctact cccagatccc cgcacacgct tagccccaga catcactgcc cctgggagca 12420 tgcacagcgc agcctcctgc cgacaaaagc aaagtcacaa aaggtgacaa aaatctgcat 12480 ttggggacat ctgattgtga aagagggagg acagtacact tgtagccaca gagactgggg 12540 ctcaccgagc tgaaacctgg tagcactttg gcataacatg tgcatgaccc gtgttcaatg 12600 tctagagatc agtgttgεgt aaaεcagcct ggtctggggc cgctgctgtc cccacttccc 12660 tcctgtccac cagagggcgg cagagttcct cccaccctgg agcctcccca ggggctgctg 12720 acctccctca gccgggccca cagcccagca gggtccaccc tcacccgggt cacctcggcc 12780 cacgtcctcc tcgccctccg agctcctcac acggactctg tcagctcctc cctgcagcct 12840 - atcggccgcc cacctgaggc ttgtcggccg cccacttgag gcctgtcggc tgccctctgc 12900 aggcagctcc tgtcccctac accccctcct tccccgggct cagctgaaag ggcgtctccc 12960 agggcagctc cctgtgatct ccaggacagc tcagtctctc acaggctccg acgcccccta 13020 tgctgtcacc tcacagccct grtcattacca ttaactcctc agtcccatga agttcactga 13080 gcgcctgtct cccggttaca ggaaaactct gtgacaggga ccacgtctgt cctgctctct 13140 gtggaεtccc agggcccagc ccagtgcctg acacggaaca gatgctccat aaatactggt 13200 taaatgtgtg ggagatctct aaaaagaagc atatcacctc cgtgtggccc ccagcagtca 13260 gagtctgttc catgtggaca caggggcact ggcaccagca tgggaggagg ccagcaagtg 13320 cccgcσgctg ccccaggaat gaggcctcaa cccccagagc ttcagaaggg aggacagagg 13380 cctgceggga atagatcctc cggcctgacc ctgcagccta atccagagtt cagggtcagc 13440 tcacaccacg tcgaccctgg tcagcatccc tagggcagtt ccagacaagg ccggaggtct 13500 cctcttgccc tccagggggt gacattgcac acagacatca ctcaggaaac ggattcccct 13560 ggacacg&a-e ctggctttgc taaggaagtg gaggtggagc ctggtttcca tcccttgctc 13620 caεcagaccc ttctgatctc tcccacatac ctgctctgtt cctttctcgg tcctεtgagg 13680 accctgttct gccaggggtc cctgtgcaac tccagactcc ctcctggtac caccatgggg 13740 aaggtggggt gatcacagga cagtcagcct cgcagagaca cagaccaccc aggactgtca 13800 gggagaacat ggacaggccc tgagccgcag ctcagccaac agacacgcag agggagggtc 13860 cccctggagc cttccccaag gacagcagag cccagagtca cccacctccc tccaccacag 1392Q tcctctcttt ccaggacaca caagacacct ccccctccac εtgcaggatc tggggactcc 13980 tgagacctct gggcctgggt ctccatccct gggtcagtgg cggggttggt ggtactggag 14040 acagagggct ggtccctccc cagccaccac ccagtgagcc tttttctagc ccccagagcc 14100 acctctgtca ccttcctgtt gggcatcatc ccaccttccc agagccctgg agagcatggg 14160 gagacccggg accctgctgg gtttctctgt cacaaaggaa aataatcccc ctggtgtgac 14220 agacccaagg acagaacaca gcagaggtca gcactgggga agacaggttg tcctcccagg 14280 ggatgggggt ccatccacct tgccgaaaag atttgtctga ggaactgaεa atagεaggga 14340 aaaεagagga gggacaaaag aggcagaaat gagaggggag gggacagagg acacctgaat 14 00 aaagaccaca. cccatgaccc acgtgatgct gagaagtact cctgccctεg gaagεgactc .14 60 I " *" transcription start site agggcagagg gaggaaggac agcagaccag acagtcacag cεgccttgεc aaaacgttcc 14S20 tggεactcaa gctcttctcc acagaggagg acagagcaga cεgcagagεc catggagtct 14580 ccqtcggccc ctccccacag atggtgcatc ccctggcaga ggctcctgct cacaggtgaa 14640 gggεggacaa cctgggagag ggtgggagga gggagctggg gtctcctgcg taggεcaggg 14700 ctgtgagacg gacagagggc tcctgttgga gcctgaatag gσaagaggεc atcagagagg 14760 gacεggagtc acaccagaaa aatcaaattg aactggaatt g aaagggcc aggaεaacct 14820 caagagttct attttcctag ttaattgtca ctggccacta cgtttttaεa aatcεtaata 14880 actgcatcag atgacacttt aaataaaaac ataaccaggg cεtgaaacεc tgtcctcatc 14940 cgcctaccgc ggacattgga aaataagccc caggctgtgg agggccctgg gaaccctcat 15000 gaactcatcc acaggaatct gcagcctgtc ccaggcactg gggtgcaacc aagatc 15056 Mucin-TRE SEQ ID NO: 15 cgagcggccc ctcagcttcg gcgcccagcc ccgcaaggct cccggtgacc actagagggc 60 gggaggagct cctggccagt ggtggagagt ggcaaggaag gaccctaggg ttcatcggag 120 cccaggttta ctcccttaag tggaaatttc ttcccccact cctccttggc tttctccaag 180 gagggaaccc aggctgctgg aaagtccggc tggggcgggg actgtgggtt caggggagaa 240 cggggtgtgg aacgggacag ggagcggtta gaagggtggg gctattccgg gaagtggtgg 300 ggggagggag cccaaaacta gcacctagtc cactcattat ccagccctct tatttctcgg 360 ccgctctgct tcagtggacc cggggagggc ggggaagtgg agtgggagac ctaggggtgg 420 gcttcccgac cttgctgtac aggacctcga cctagctggc tttgttcccc atccccacgt 480 tagttgttgc cctgaggcta aaactagagc ccaggggccc caagttccag actgcccctc 540 ccccctcccc cggagccagg gagtggttgg tgaaaggggg aggccagctg gagaacaaac 600 gggtagtcag ggggttgagc gattagagcc cttgtaccct acccaggaat ggttggggag 660 gaggaggaag aggtaggagg taggggaggg ggcggggttt tgtcacctgt cacctgctcg 720 ctgtgcctag ggcgggcggg cggggagtgg ggggaccggt ataaagcggt aggcgcctgt 780 gcccgctcca cctctcaagc agccagcgcc tgcctgaatc tgttctgccc cctccccacc 840 catttcacca ccaccatg 858 αFP-TRE SEQ ID NO:16 gaattcttag aaatatgggg gtaggggtgg tggtggtaat tctgttttca ccccataggt 60 gagataagca ttgggttaaa tgtgctttca cacacacatc acatttcata agaattaagg 120 aacagactat gggctggagg actttgagga tgtctgtctc ataacacttg ggttgtatct 180 gttctatggg gcttgtttta agcttggcaa cttgcaacag ggttcactga ctttctcccc 240 aagcccaagg tactgtcctc ttttcatatc tgttttgggg cctctggggc ttgaatatct 300 gagaaaatat aaacatttca ataatgttct gtggtgagat gagtatgaga gatgtgtcat 360 tcatttgtat caatgaatga atgaggacaa ttagtgtata aatccttagt acaacaatct 420 gagggtaggg gtggtactat tcaatttcta tttataaaga tacttatttc tatttattta 480 tgcttgtgac aaatgttttg ttcgggacca caggaatcac aaagatgagt ctttgaattt 540 aagaagttaa tggtccagga ataattacat agcttacaaa tgactatgat ataccatcaa 600 acaagaggtt ccatgagaaa ataatctgaa aggtttaata agttgtcaaa ggtgagaggg 660 ctcttctcta gctagagact aatcagaaat acattcaggg ataattattt gaatagacct 720 taagggttgg gtacattttg ttcaagcatt gatggagaag gagagtgaat atttgaaaac 780 attttcaact aaccaaccac ccaatccaac aaacaaaaaa tgaaaagaat ctcagaaaca 840 gtgagataag agaaggaatt ttctcacaac ccacacgtat agctcaactg ctctgaagaa 900 gtatatatct aatatttaac actaacatca tgctaataat gataataatt actgtcattt 960 tttaatgtct ataagtacca ggcatttaga agatattatt ccatttatat atcaaaataa 1020 acttgagggg atagatcatt ttcatgatat atgagaaaaa ttaaaaacag attgaattat 1080 ttgcctgtca tacagctaat aattgaccat aagacaatta gatttaaatt agttttgaat 1140 ctttctaata ccaaagttca gtttactgtt ccatgttgct tctgagtggc ttcacagact 1200 tatgaaaaag taaacggaat cagaattaca tcaatgcaaa agcattgctg tgaactctgt 1260 acttaggact aaactttgag caataacaca catagattga ggattgtttg ctgttagcat 1320 acaaactctg gttcaaagct cctctttatt gcttgtcttg gaaaatttgc tgttcttcat 1380 ggtttctctt ttcactgcta tctatttttc tcaaccactc acatggctac aataactgtc 1440 tgcaagctta tgattcccaa atatctatct ctagcctcaa tcttgttcca gaagataaaa 1500 agtagtattc aaatgcacat caacgtctcc acttggaggg cttaaagacg tttcaacata 1560 caaaccgggg agttttgcct ggaatgtttc ctaaaatgtg tcctgtagca catagggtcc 1620 tcttgttcct taaaatctaa ttacttttag cccagtgctc atcccaccta tggggagatg 1680 agagtgaaaa gggagcctga ttaataatta cactaagtca ataggcatag agccaggact 1740 gtttgggtaa actggtcact ttatcttaaa ctaaatatat ccaaaactga acatgtactt 1800 agttactaag tctttgactt tatctcattc ataccactca gctttatcca ggccacttat 1860 ttgacagtat tattgcgaaa acttcctaac tggtctcctt atcatagtct tatccccttt 1920 tgaaacaaaa gagacagttt caaaatacaa atatgatttt tattagctcc cttttgttgt 1980 ctataatagt cccagaagga gttataaact ccatttaaaa agtctttgag atgtggccct 2040 tgccaacttt gccaggaatt cccaatatct agtattttct actattaaac tttgtgcctc 2100 ttcaaaactg cattttctct cattccctaa gtgtgcattg ttttccctta ccggttggtt 2160 tttccaccac cttttacatt ttcσtggaac actataccct ccctcttcat ttggcccacc 2220 tctaattttc tttcagatct ccatgaagat gttacttcct ccaggaagcc ttatctgacc 2280 cctccaaaga tgtcatgagt tcctcttttc attctactaa tcacagcatc catcacacca 2340 tgttgtgatt actgatacta ttgtctgttt ctctgattag gcagtaagct caacaagagc 2400 tacatggtgc ctgtctcttg ttgctgatta ttcccatcca aaaacagtgc ctggaatgca 2460 gacttaacat tttattgaat gaataaataa aaccccatct atcgagtgct actttgtgca 2520 agacccggtt ctgaggcatt tatatttatt gatttattta attctcattt aaccatgaag 2580 gaggtactat cactatcctt attttatagt tgataaagat aaagcccaga gaaatgaatt 2640 aactcaccca aagtcatgta gctaagtgac agggcaaaaa ttcaaaccag ttccccaact 2700 ttacgtgatt aatactgtgc tatactgcct ctctgatcat atggcatgga atgcagacat 2760 ctgctccgta aggcagaata tggaaggaga ttggaggatg acacaaaacc agcataatat 2820 cagaggaaaa gtccaaacag gacctgaact gatagaaaag ttgttactcc tggtgtagtc 2880 gcatcgacat cttgatgaac tggtggctga cacaacatac attggcttga tgtgtacata 2940 ttatttgtag ttgtgtgtgt atttttatat atatatttgt aatattgaaa tagtcataat 3000 ttactaaagg cctaccattt gccaggcatt tttacatttg tcccctctaa tcttttgatg 3060 agatgatcag attggattac ttggccttga agatgatata tctacatcta tatctatatc 3120 tatatctata tctatatcta tatctatatc tatatctata tatgtatatc agaaaagctg 3180 aaatatgttt tgtaaagtta taaagatttc agactttata gaatctggga tttgccaaat 3240 gtaacccctt tctctacatt aaacccatgt tggaacaaat acatttatta ttcattcatc 3300 aaatgttgct gagtcctggc tatgaaccag acactgtgaa agcctttggg atattttgcc 3360 catgcttggg caagcttata tagtttgctt cataaaactc tatttcagtt cttcataact 3420 aatacttcat gactattgct tttcaggtat tccttcataa caaatacttt ggctttcata 3480 tatttgagta aagtccccct tgaggaagag tagaagaact gcactttgta aatactatcc 3540 tggaatccaa acggatagac aaggatggtg ctacctcttt ctggagagta cgtgagcaag 3600 gcctgttttg ttaacatgtt ccttaggaga caaaacttag gagagacacg catagcagaa 3660 aatggacaaa aactaacaaa tgaatgggaa ttgtacttga ttagcattga agaccttgtt 3720 tatactatga taaatgtttg tatttgctgg aagtgctact gacggtaaac cctttttgtt 3780 taaatgtgtg ccctagtagc ttgcagtatg atctattttt taagtactgt acttagctta 3840 tttaaaaatt ttatgtttaa aattgcatag tgctctttca ttgaagaagt tttgagagag 3900 agatagaatt aaattcactt atcttaccat ctagagaaac ccaatgttaa aactttgttg 3960 tccattattt ctgtctttta ttcaacattt tttttagagg gtgggaggaa tacagaggag 4020 gtacaatgat acacaaatga gagcactctc catgtattgt tttgtcctgt ttttcagtta 4080 acaatatatt atgagcatat ttccatttca ttaaatattc ttccacaaag ttattttgat 4140 ggctgtatat caccctactt tatgaatgta ccatattaat ttatttcctg gtgtgggtta 4200 tttgatttta taatcttacc tttagaataa tgaaacacct gtgaagcttt agaaaatact 4260 ggtgcctggg tctcaactcc acagattctg atttaactgg tctgggttac agactaggca 4320 ttgggaattc aaaaagttcc cccagtgatt ctaatgtgta gccaagatcg ggaacccttg 4380 tagacaggga tgataggagg tgagccactc ttagcatcca tcatttagta ttaacatcat 4440 catcttgagt tgctaagtga atgatgcacc tgacccactt tataaagaca catgtgcaaa 4500 taaaattatt ataggacttg gtttattagg gcttgtgctc taagttttct atgttaagcc 4560 atacatcgca tactaaatac tttaaaatgt accttattga catacatatt aagtgaaaag 4620 tgtttctgag ctaaacaatg acagcataat tatcaagcaa tgataatttg aaatgaattt 4680 attattctgc aacttaggga caagtcatct ctctgaattt tttgtacttt gagagtattt 4740 gttatatttg caagatgaag agtctgaatt ggtcagacaa tgtcttgtgt gcctggcata 4800 tgataggcat ttaatagttt taaagaatta atgtatttag atgaattgca taccaaatct 4860 gctgtctttt ctttatggct tcattaactt aatttgagag aaattaatta ttctgcaact 4920 tagggacaag tcatgtcttt gaatattctg tagtttgagg agaatatttg ttatatttgc 4980 aaaataaaat aagtttgcaa gttttttttt tctgccccaa agagctctgt gtccttgaac 5040 ataaaataca aataaccgct atgctgttaa ttattggcaa atgtcccatt ttcaacctaa 5100 ggaaatacca taaagtaaca gatataccaa caaaaggtta ctagttaaca ggcattgcct 5160 gaaaagagta taaaagaatt tcagcatgat tttccatatt gtgcttccac cactgccaat 5220 aaca 5224

Claims: CLAIMS What is claimed is: 1. A replication-competent adenovirus vector comprising first and second genes co-transcribed as a single mRNA wherein the first and the second genes are under transcriptional control of a heterologous, target cell-specific transcriptional regulatory element (TRE), wherein the second gene has a mutation in or deletion of its endogenous promoter and is under translational control of an internal ribosome entry site (IRES) and wherein said vector exhibits greater specificity for the target cell than an adenovirus vector comprising a target cell-specific TRE operably linked to a gene and lacking an IRES . 2. The vector of Claim 1 , wherein at least one of said first and second genes is an adenovirus gene. 3. The vector of Claim 2, wherein both of said first and said second genes are adenovirus genes. 4. The vector of Claim 2, wherein at least one of said first and said second adenovirus^gene is essential for viral replication. 5. The vector of Claim 4, wherein the adenovirus gene essential for viral- replication is an adenovirus early gene. 6. The vector of Claim 5, wherein the adenovirus early gene includes EIA, ElB, E2, or E4. 7. The vector of Claim 4, wherein the adenovirus gene essential for viral replication is an adenovirus late gene. 8. The vector of Claim 3, wherein both said first and said second adenovirus genes are essential for viral replication. 9. The vector of Claim 8, wherein at least one of said first and said second adenovirus genes is an adenovirus early gene. 10. The vector of Claim 8, wherein at least one of said first and said second adenovirus genes is an adenovirus late gene. 11. The vector of Claim 8, wherein said first adenovirus gene is EIA and said second adenovirus gene is EIB. 12. The vector of Claim 11 wherein EIA has its endogenous promoter deleted. 13. The vector of Claim 11 wherein EIA has an inactivation of E 1 A enhancer I 14. The vector of Claim 11 wherein EIB has an inactivation of its endogenous promoter. 15. The vector of Claim 11 wherein EIB has a deletion ofthe 19-kDa region. 16. The vector of Claim 11 wherein EIA has an inactivation of its endogenous promoter and EIB has an inactivation of its endogenous promoter. 17. The vector of Claim 16 wherein EIB has a deletion ofthe 19-kDa region. 18. The vector of Claim 16 wherein EIA has an inactivation of EIA enhancer I. 19. The vector of Claim 1, wherein the internal ribosome entry site (IRES) is from EMCV. 20. The vector of Claim 1 wherein the IRES is from VEGF. 21. The vector of Claim 1 wherein the IRES includes the 5'UTR of HCV; the 5' UTR of BiP; or the 5'UTR of PDGF. 22. The vector of Claim 1, wherein the TRE is specific for a target cell that is a cancer cell. 23. The vector of Claim 22 wherein the cancer cell includes a prostate cancer cell, a breast cancer cell, a hepatoma cell, a melanoma cell, a bladder cell or a colon cancer cell. 24. The vector of Claim 22, wherein the TRE includes the probasin (PB) TRE, the prostate-specific antigen (PSA) TRE, the mucin {MUCl) TRE, the α-fetoprotein (AFP) TRE, the hKLK2 TRE, the tyrosinase TRE, the human uroplakin II (hUPII) TRE or the carcinoembryonic antigen (CEA) TRE. 25. The vector of Claim 9 wherein said first adenovirus gene has a deletion of its endogenous promoter. 26. The vector of Claim 25 wherein said first adenovirus gene is El A. 27. The vector of Claim 9 wherein said first and/or said second adenovirus gene has a deletion of an enhancer region. 28. The vector of Claim 27 wherein said first gene is EIA and said enhancer is EIA enhancer I. 29. The vector of Claim 1 wherein said TRE has an endogenous silencer element deleted. 30. The vector of Claim 1 wherein said adenovirus vector comprises an E3 region. 31. The adenovirus vector of Claim 11 wherein said adenovirus comprises an E3 region. 32. The adenovirus vector of Claim 11 further comprising a transgene. 33. An adenovirus vector comprising a gene under transcriptional control of a melanocyte-specific TRE. 34. The vector of Claim 33 wherein said gene is an adenoviral gene. 35. The vector of Claim 34 wherein said adenoviral gene is a gene essential for replication. 36. The vector of Claim 32 wherein said transgene is co-transcribed with said first and said second gene and said transgene is under the translation control of a separate internal ribosome entry site (IRES). 37. The vector of Claim 36 wherein said IRES is from EMCV. 38. The vector of Claim 36 wherein said IRES is from VEGF. 39. The vector of Claim 30 further comprising an adenovirus death protein gene (ADP). 40. The vector of Claim 32 wherein said transgene is a cytotoxic gene. 41. The vector of Claim 1 wherein said first adenovirus gene is essential for viral replication and said second adenovirus gene is the adenovirus death protein gene (ADP). 42. The vector of Claim 41 wherein said first adenovirus gene is EIA. 43. The vector of Claim 42 wherein EIA has a deletion of its endogenous promoter. 44. The vector of Claim 42 wherein said EIA has a deletion of El A enhancer I. 45. The vector of Claim 1 wherein said first gene is essential for viral replication and said second gene is E3. 46. The vector of Claim 45 wherein said first gene is El A. 47. A composition comprising a vector according to Claim 1. 48. The composition of Claim 47 further comprising a pharmaceutically acceptable excipient. 49. A composition comprising a vector according to Claim 30. 50. The composition of Claim 49 further comprising a pharmaceutically acceptable excipient. 51. A host cell comprising the vector of Claim 1. 52. A host cell comprising the vector of Claim 30. 53. An adenovirus vector comprising EIB under transcriptional control of a heterologous, target cell specific TRE, wherein EIB has a deletion of part or all ofthe 19- kDa region. 54. A host cell comprising the adenovirus vector of claim 53. 55. A method for propagating a replication-competent adenovirus vector comprising a target cell-specific TRE, said method comprising combining an adenovirus vector of Claim 1 with mammalian cells that permit the function of a target cell-specific TRE, such that the adenovirus vector enters the cell, whereby said adenovirus vector is propagated. 56. A method for conferring selective cytotoxicity in target cells, comprising contacting the cells with an adenovirus vector of Claim 41 whereby the vector enters the cell. 57. A method for modifying the genotype of a target cell, comprising contacting the cell with an adenovirus vector of Claim 1, wherein the vector enters the cell. 58. A method for suppressing tumor cell growth, comprising contacting a tumor cell with an adenovirus vector of Claim 41 such that the adenovirus vector enters the tumor cell and exhibits selective cytotoxicity for the tumor cell.

Inventors: HENDERSON DANIEL R, LI YUANHAO, YU DE-CHAO, HENDERSON, DANIEL, R., LI, YUANHAO, YU, DE-CHAO
Applicants: CALYDON INC, HENDERSON DANIEL R, LI YUANHAO, YU DE CHAO, CALYDON, INC., HENDERSON, DANIEL, R., LI, YUANHAO, YU, DE-CHAO
Application year: 2001
Main classification: C12N15
IPC codes: A61K35, A61K38, A61K48, A61P35, C12N1, C12N5, C12N7, C12N15