bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypermethylation of CpG Islands in Primary and Metastatic Human Prostate Cancer
Authors: Yegnasubramanian Srinivasan , Kowalski Jeanne , Gonzalgo Mark L. , Zahurak Marianna , Piantadosi Steven , Walsh Patrick C. , Bova G. Steven , De Marzo Angelo M. , Isaacs William B. , Nelson William G.
Published: September 2005

Aberrant DNA methylation patterns may be the earliest somatic genome changes in prostate cancer. Using real-time methylation-specific PCR, we assessed the extent of hypermethylation at 16 CpG islands in DNA from seven prostate cancer cell lines (LNCaP, PC-3, DU-145, LAPC-4, CWR22Rv1, VCaP, and C42B), normal prostate epithelial cells, normal prostate stromal cells, 73 primary prostate cancers, 91 metastatic prostate cancers, and 25 noncancerous prostate tissues. We found that CpG islands at GSTP1, APC, RASSF1a, PTGS2, and MDR1 were hypermethylated in >85% of prostate cancers and cancer cell lines but not in normal prostate cells and tissues; CpG islands at EDNRB, ESR1, CDKN2a, and hMLH1 exhibited low to moderate rates of hypermethylation in prostate cancer tissues and cancer cell lines but were entirely unmethylated in normal tissues; and CpG islands at DAPK1, TIMP3, MGMT, CDKN2b, p14/ARF, and CDH1 were not abnormally hypermethylated in prostate cancers. Receiver operator characteristic curve analyses suggested that CpG island hypermethylation changes at GSTP1, APC, RASSF1a, PTGS2, and MDR1 in various combinations can distinguish primary prostate cancer from benign prostate tissues with sensitivities of 97.3–100% and specificities of 92–100%. Hypermethylation of the CpG island at EDNRB was correlated with the grade and stage of the primary prostate cancers. PTGS2 CpG island hypermethylation portended an increased risk of recurrence. Furthermore, CpG island hypermethylation patterns in prostate cancer metastases were very similar to the primary prostate cancers and tended to show greater differences between cases than between anatomical sites of metastasis.
The CpG Island Methylator Phenotype Is Not Associated with a Personal or Family History of Cancer
Authors: Ward Robyn Lynne , Williams Rachel , Law Matthew , Hawkins Nicholas John
Published: September 2005

Colorectal cancers with widespread CpG island methylation display a number of distinct clinicopathological features, and it has been suggested that the condition has an inheritable genetic component. To address this possibility, histories of cancer were obtained from 562 individuals undergoing curative surgery for unselected colorectal cancer at one institution. Microsatellite status and methylation at p16, MINT1, 2, 12, and 31 loci were determined on fresh tumor tissue using standard methods. Fifty-five of 562 probands in this study provided a personal history of at least one other colorectal cancer, 10 reported at least one extracolonic cancer of hereditary nonpolyposis colorectal cancer type, and 84 individuals had another type of cancer. Age was strongly associated with the risk of multiple cancers, but there was no evidence that microsatellite instability or the CpG island methylator phenotype were independent risk factors for their development, either in the colorectum or elsewhere. Of the 547 individuals with knowledge of their family history, 80 (14.6%) reported a family history of colorectal cancer in a first-degree relative, and 60% of individuals reported a history of any cancer in a first-degree relative. Neither tumor CpG island methylator phenotype status nor microsatellite instability was predictive of a positive history of cancer in first- or second-degree relatives. The probability of a positive family or personal history of cancer did not increase with increasing number of methylated loci. Epigenetic silencing of multiple genes seen in some tumors is at best rarely the result of an inherited defect in the methylation apparatus. There is no justification for altering the personal or family cancer screening recommendations on the basis of tumor CpG island methylator phenotype status.
MAT1-Modulated Cyclin-Dependent Kinase-Activating Kinase Activity Cross-Regulates Neuroblastoma Cell G1 Arrest and Neurite Outgrowth
Authors: Zhang Shineng , He Qiaojun , Peng Hui , Tedeschi-Blok Nicole , Triche Timothy J. , Wu Lingtao
Published: September 2005

Cyclin-dependent kinase-activating kinase (CAK) regulates cell cycle G1 exit, where cells commonly commit either to proliferate or to differentiate. CAK activity in G1 regulation is determined by its assembly factor and targeting subunit, ménage à trois 1 (MAT1). The precise mechanism of how proliferation/differentiation transition is induced from cancer cell G1 arrest remains unknown. We present evidence that in neuroblastoma CHP126 cells, CAK interacts with and phosphorylates retinoblastoma tumor suppressor protein (pRb) and retinoid X receptor α (RXRα). Retinoic acid (RA)-induced neuroblastoma cell proliferation/differentiation transition is associated with decreased CAK activity, as evidenced by a switch from CAK hyperphosphorylation of pRb and RXRα to hypophosphorylation of pRb and RXRα. Manipulation of MAT1 abundance shows that MAT1 reduction mimics RA-induced hypophosphorylation of pRb/RXRα, proliferation inhibition, and neurite outgrowth, whereas MAT1 overexpression resists these RA actions. Thus, these findings reveal an important mechanism by which MAT1-modulated CAK activity is crucial in the switch from proliferation to differentiation in neuroblastoma cells.
Functional Analysis of Novel
Sonic Hedgehog
Gene Mutations Identified in Basal Cell Carcinomas from Xeroderma Pigmentosum Patients
Authors: Couvé-Privat Sophie , Le Bret Marc , Traiffort Elisabeth , Queille Sophie , Coulombe Josée , Bouadjar Bakar , Avril Marie Françoise , Ruat Martial , Sarasin Alain , Daya-Grosjean Leela
Published: September 2005

Altered sonic hedgehog (SHH) signaling is crucial in the development of basal cell carcinomas (BCC), the most common human cancer. Mutations in SHH signal transducers, PATCHED and SMOOTHENED, have already been identified, but SHH mutations are extremely rare; only 1 was detected in 74 sporadic BCCs. We present data showing unique SHH mutations in BCCs from repair-deficient, skin cancer-prone xeroderma pigmentosum (XP) patients, which are characterized by high levels of UV-specific mutations in key genes involved in skin carcinogenesis, including PATCHED and SMOOTHENED. Thus, 6 UV-specific SHH mutations were detected in 5 of 33 XP BCCs. These missense SHH alterations are not activating mutations for its postulated proto-oncogene function, as the mutant SHH proteins do not show transforming activity and induce differentiation or stimulate proliferation to the same level as the wild-type protein. Structural modeling studies of the 4 proteins altered at the surface residues, G57S, G64K, D147N, and R155C, show that they do not effect the protein conformation. Interestingly, they are all located on one face of the compact SHH protein suggesting that they may have altered affinity for different partners, which may be important in altering other functions. Additional functional analysis of the SHH mutations found in vivo in XP BCCs will help shed light on the role of SHH in skin carcinogenesis. In conclusion, we report for the first time, significant levels of SHH mutations found only in XP BCCs and none in squamous cell carcinomas, indicating their importance in the specific development of BCCs.
G-Quartet Oligonucleotides
Authors: Jing Naijie , Li Yidong , Xiong Weijun , Sha Wei , Jing Ling , Tweardy David J.
Published: September 2005

Stat3 is a signaling molecular and oncogene activated frequently in many human malignancies including the majority of prostate, breast, and head and neck cancers; yet, no current chemotherapeutic approach has been implemented clinically that specifically targets Stat3. We recently developed G-rich oligodeoxynucleotides, which form intramolecular G-quartet structures (GQ-ODN), as a new class of Stat3 inhibitor. GQ-ODN targeted Stat3 protein directly inhibiting its ability to bind DNA. When delivered into cells using polyethyleneimine as vehicle, GQ-ODN blocked ligand-induced Stat3 activation and Stat3-mediated transcription of antiapoptotic genes. To establish the effectiveness of GQ-ODN as a potential new chemotherapeutic agent, we systemically administered GQ-ODN (T40214 or T40231) plus polyethyleneimine or polyethyleneimine alone (placebo) by tail-vein injection into nude mice with prostate and breast tumor xenografts. Whereas the mean volume of breast tumor xenografts in placebo-treated mice increased >7-fold over 18 days, xenografts in the GQ-ODN-treated mice remained unchanged. Similarly, whereas the mean volume of prostate tumor xenografts in placebo-treated mice increased 9-fold over 10 days, xenografts in GQ-ODN-treated mice increased by only 2-fold. Biochemical examination of tumors from GQ-ODN-treated mice demonstrated a significant reduction in Stat3 activation, levels of the antiapoptotic proteins Bcl-2 and Bcl-xL, and an 8-fold increase in the number of apoptotic cells compared with the tumors of placebo-treated mice. Thus, GQ-ODN targeting Stat3 induces tumor cell apoptosis when delivered into tumor xenografts and represents a novel class of chemotherapeutic agents that holds promise for the systemic treatment of many forms of metastatic cancer.
Genome-Wide Array-Based Comparative Genomic Hybridization of Diffuse Large B-Cell Lymphoma
Authors: Tagawa Hiroyuki , Tsuzuki Shinobu , Suzuki Ritsuro , Karnan Sivasundaram , Ota Akinobu , Kameoka Yoshihiro , Suguro Miyuki , Matsuo Keitaro , Yamaguchi Motoko , Okamoto Masataka , Morishima Yasuo , Nakamura Shigeo , Seto Masao
Published: September 2005

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin’s lymphoma and exhibits aggressive and heterogeneous clinical behavior. To genetically characterize DLBCL, we established our own array-based comparative genomic hybridization and analyzed a total of 70 cases [26 CD-positive (CD5+) DLBCL and 44 CD5-negative (CD5−) DLBCL cases]. Regions of genomic aberrations observed in >20% of cases of both the CD5+ and CD5− groups were gains of 1q21-q31, 1q32, 3p25-q29, 5p13, 6p21-p25, 7p22-q31, 8q24, 11q23-q24, 12q13-q21, 16p13, 18, and X and losses of 1p36, 3p14, 6q14-q25, 6q27, 9p21, and 17p11-p13. Because CD5 expression marks a subgroup with poor prognosis, we subsequently analyzed genomic gains and losses of CD5+ DLBCL compared with those of CD5−. Although both groups showed similar genomic patterns of gains and losses, gains of 10p14-p15 and 19q13 and losses of 1q43-q44 and 8p23 were found to be characteristic of CD5+ DLBCL. By focusing on the gain of 13q21-q34 and loss of 1p34-p36, we were also able to identify prognostically distinct subgroups among CD5+ DLBCL cases. These results suggest that array-based comparative genomic hybridization analysis provides a platform of genomic aberrations of DLBCL both common and specific to clinically distinct subgroups.
Comparative Pathology of Nerve Sheath Tumors in Mouse Models and Humans
Authors: Stemmer-Rachamimov Anat O. , Louis David N. , Nielsen Gunnlaugur P. , Antonescu Cristina R. , Borowsky Alexander D. , Bronson Roderick T. , Burns Dennis K. , Cervera Pascale , McLaughlin Margaret E. , Reifenberger Guido , Schmale Michael C. , MacCollin Mia , Chao Richard C. , Cichowski Karen , Kalamarides Michel , Messerli Shanta M. , McClatchey Andrea I. , Niwa-Kawakita Michiko , Ratner Nancy , Reilly Karlyne M. , Zhu Yuan , Giovannini Marco
Published: September 2005

Despite the progress made in our understanding of the biology of neurofibromatosis (NF), the long-term clinical outcome for affected patients has not changed significantly in the past decades, and both NF1 and NF2 are still associated with a significant morbidity and a decreased life span. A number of NF1 and NF2 murine models have been generated to aid in the study of NF tumor biology and in the development of targeted therapies for NF patients. A single, universal pathological classification of the lesions generated in these murine models is essential for the validation of the models, for their analysis and comparison with other models, and for their future effective use in preclinical treatment trials. For the formulation of a pathological classification of these lesions, the WHO classification of human tumors was used as a reference. However, it was not adopted for the classification of the GEM lesions because of some important differences between the human and murine lesions. A novel classification scheme for peripheral nerve sheath tumors in murine models was therefore devised.
BRCA1 Interacts with and Is Required for Paclitaxel-Induced Activation of Mitogen-Activated Protein Kinase Kinase Kinase 3
Authors: Gilmore Paula M. , McCabe Nuala , Quinn Jennifer E. , Kennedy Richard D. , Gorski Julia J. , Andrews Heather N. , McWilliams Stewart , Carty Michael , Mullan Paul B. , Duprex W. Paul , Liu Edison T. , Johnston Patrick G. , Harkin D. Paul
Published: September 2005

BRCA1 has been implicated in a number of cellular processes, including transcriptional regulation, DNA damage repair, cell cycle arrest, and apoptosis. We identified mitogen-activated protein kinase (MAPK) kinase kinase 3 (MEKK3), an upstream regulator of the c-Jun NH2-terminal kinase/stress-activated protein kinase and p38/MAPK pathways, as a novel BRCA1-interacting protein in a yeast two-hybrid screen and confirmed the interaction by coimmunoprecipitation in mammalian cells. Deletion mapping demonstrated that amino acids 1611–1863 are required to mediate the interaction with MEKK3 in yeast. BRCA1 disease-associated mutations abrogated the interaction in yeast, and BRCA1 failed to interact with MEKK3 in BRCA1 mutant HCC1937 breast cancer cells. We demonstrate that small interfering RNA-based inhibition of endogenous BRCA1 reduces MEKK3 kinase activity and conversely that inducible expression of BRCA1 activates MEKK3 and p38/MAPK. Finally, we demonstrate using complementary approaches that BRCA1 is required for paclitaxel-induced activation of MEKK3. These data indicate that BRCA1 is a key regulator of the paclitaxel-induced stress response pathway and suggest that the ability of BRCA1 to associate with, and mediate the activation of, MEKK3 represents a potential mechanism through which this pathway is regulated.
Pro-Matrix Metalloproteinase-2 Transfection Increases Orthotopic Primary Growth and Experimental Metastasis of MDA-MB-231 Human Breast Cancer Cells in Nude Mice
Authors: Tester Angus M. , Waltham Mark , Oh Se-Jeong , Bae Seog-Nyeon , Bills Margaret M. , Walker Emma C. , Kern Francis G. , Stetler-Stevenson William G. , Lippman Marc E. , Thompson Erik W.
Published: September 2005

The ability to activate pro-matrix metalloproteinase (pro-MMP)-2 via membrane type-MMP is a hallmark of human breast cancer cell lines that show increased invasiveness, suggesting that MMP-2 contributes to human breast cancer progression. To investigate this, we have stably transfected pro-MMP-2 into the human breast cancer cell line MDA-MB-231, which lacks MMP-2 expression but does express its cell surface activator, membrane type 1-MMP. Multiple clones were derived and shown to produce pro-MMP-2 and to activate it in response to concanavalin A. In vitro analysis showed that the pro-MMP-2-transfected clones exhibited an increased invasive potential in Boyden chamber and Matrigel outgrowth assays, compared with the parental cells or those transfected with vector only. When inoculated into the mammary fat pad of nude mice, each of the MMP-2-tranfected clones grew faster than each of the vector controls tested. After intracardiac inoculation into nude mice, pro-MMP-2-transfected clones showed a significant increase in the incidence of metastasis to brain, liver, bone, and kidney compared with the vector control clones but not lung. Increased tumor burden was seen in the primary site and in lung metastases, and a trend toward increased burden was seen in bone, however, no change was seen in brain, liver, or kidney. This data supports a role for MMP-2 in breast cancer progression, both in the growth of primary tumors and in their spread to distant organs. MMP-2 may be a useful target for breast cancer therapy when refinement of MMP inhibitors provides for MMP-specific agents.
Cotreatment with 17-Allylamino-Demethoxygeldanamycin and FLT-3 Kinase Inhibitor PKC412 Is Highly Effective against Human Acute Myelogenous Leukemia Cells with Mutant FLT-3
Authors: George Prince , Bali Purva , Cohen Pamela , Tao Jianguo , Guo Fei , Sigua Celia , Vishvanath Anasuya , Fiskus Warren , Scuto Anna , Annavarapu Srinivas , Moscinski Lynn , Bhalla Kapil
Published: September 2005

Presence of the activating length mutation (LM) in the juxtamembrane domain or point mutation in the kinase domain of FMS-like tyrosine kinase-3 (FLT-3) mediates ligand-independent progrowth and prosurvival signaling in approximately one-third of acute myelogenous leukemia (AML). PKC412, an inhibitor of FLT-3 kinase activity, is being clinically evaluated in AML. Present studies demonstrate that treatment of human acute leukemia MV4-11 cells (containing a FLT-3 LM) with the heat shock protein 90 inhibitor 17-allylamino-demethoxy geldanamycin (17-AAG) attenuated the levels of FLT-3 by inhibiting its chaperone association with heat shock protein 90, which induced the poly-ubiquitylation and proteasomal degradation of FLT-3. Treatment with 17-AAG induced cell cycle G1 phase accumulation and apoptosis of MV4-11 cells. 17-AAG-mediated attenuation of FLT-3 and p-FLT-3 in MV4-11 cells was associated with decrease in the levels of p-AKT, p-ERK1/2, and p-STAT5, as well as attenuation of the DNA binding activity of STAT-5. Treatment with 17-AAG, downstream of STAT5, reduced the levels of c-Myc and oncostatin M, which are transactivated by STAT5. Cotreatment with 17-AAG and PKC412 markedly down-regulated the levels of FLT-3, p-FLT-3, p-AKT, p-ERK1/2, and p-STAT5, as well as induced more apoptosis of MV4-11 cells than either agent alone. Furthermore, the combination of 17-AAG and PKC412 exerted synergistic cytotoxic effects against MV4-11 cells. Importantly, 17-AAG and PKC412 induced more loss of cell viability of primary AML blasts containing FLT-3 LM, as compared with those that contained wild-type FLT-3. Collectively, these in vitro findings indicate that the combination of 17-AAG and PKC412 has high level of activity against AML cells with FLT-3 mutations.
Systematic Review of Genomic Integration Sites of Human Papillomavirus Genomes in Epithelial Dysplasia and Invasive Cancer of the Female Lower Genital Tract
Authors: Wentzensen Nicolas , Vinokurova Svetlana , Doeberitz Magnus von Knebel
Published: September 2005

Cancers of the anogenital tract as well as some head and neck cancers are caused by persistent infections with high-risk type human papillomaviruses (HPVs). Two viral oncogenes, E6 and E7, induce severe chromosomal instability associated with centrosome aberrations, anaphase bridges, chromosome lagging, and breaking. This occurs early in preneoplastic lesions, when the viral genome still persists in an episomal state. In most invasive cancers and also in a few high-grade dysplastic lesions, however, integration of high-risk HPV genomes into the host genome is observed. Integration seems to be a direct consequence of chromosomal instability and an important molecular event in the progression of preneoplastic lesions. Disruption or deregulation of defined critical cellular gene functions by insertional mutagenesis by integrated HPV genome fragments has been hypothesized as one major promoting factor in the pathogenesis of HPV-associated cancers. This hypothesis was based on the detection of HPV integration events in the area of tumor-relevant genes in few cases. Here, we reviewed >190 reported integration loci with respect to changes in the viral structure and the targeted genomic locus. This analysis confirms that HPV integration sites are randomly distributed over the whole genome with a clear predilection for genomic fragile sites. No evidence for targeted disruption or functional alteration of critical cellular genes by the integrated viral sequences could be found.
Molecular Features of the Transition from Prostatic Intraepithelial Neoplasia (PIN) to Prostate Cancer
Authors: Ashida Shingo , Nakagawa Hidewaki , Katagiri Toyomasa , Furihata Mutsuo , Iiizumi Megumi , Anazawa Yoshio , Tsunoda Tatsuhiko , Takata Ryo , Kasahara Kotaro , Miki Tsuneharu , Fujioka Tomoaki , Shuin Taro , Nakamura Yusuke
Published: September 2005

To characterize the molecular feature in prostate carcinogenesis and the putative transition from prostatic intraepithelial neoplasia (PIN) to invasive prostate cancer (PC), we analyzed gene-expression profiles of 20 PCs and 10 high-grade PINs with a cDNA microarray representing 23,040 genes. Considering the histological heterogeneity of PCs and the minimal nature of PIN lesions, we applied laser microbeam microdissection to purify populations of PC and PIN cells, and then compared their expression profiles with those of corresponding normal prostatic epithelium also purified by laser microbeam microdissection. A hierarchical clustering analysis separated the PC group from the PIN group, except for three tumors that were morphologically defined as one very-high-grade PIN and two low-grade PCs, suggesting that PINs and PCs share some molecular features and supporting the hypothesis of PIN-to-PC transition. On the basis of this hypothesis, we identified 21 up-regulated genes and 63 down-regulated genes commonly in PINs and PCs compared with normal epithelium, which were considered to be involved in the presumably early stage of prostatic carcinogenesis. They included AMACR, OR51E2, RODH, and SMS. Furthermore, we identified 41 up-regulated genes and 98 down-regulated genes in the transition from PINs to PCs; those altered genes, such as POV1, CDKN2C, EPHA4, APOD, FASN, ITGB2, LAMB2, PLAU, and TIMP1, included elements that are likely to be involved in cell adhesion or the motility of invasive PC cells. The down-regulation of EPHA4 by small interfering RNA in PC cells lead to attenuation of PC cell viability. These data provide clues to the molecular mechanisms underlying prostatic carcinogenesis, and suggest candidate genes the products of which might serve as molecular targets for the prevention and treatment of PC.
The
HMG-I
Oncogene Causes Highly Penetrant, Aggressive Lymphoid Malignancy in Transgenic Mice and Is Overexpressed in Human Leukemia
Authors: Xu Yi , Sumter Takita Felder , Bhattacharya Raka , Tesfaye Abeba , Fuchs Ephraim J. , Wood Lisa J. , Huso David L. , Resar Linda M. S.
Published: September 2005

HMG-I/Y is overexpressed in human cancer, although a direct role for this gene in transformation has not been established. We generated transgenic mice with HMG-I targeted to lymphoid cells. All seven informative founder HMG-I mice developed aggressive lymphoma by a mean age of 4.8 months. Tumors express T-cell markers and are transplantable. We also demonstrate that HMG-I mRNA and protein are increased in human acute lymphocytic leukemia samples. Our results show that HMG-I functions as an oncogene and suggest that it contributes to the pathogenesis of leukemia and other cancers with increased HMG-I expression.
X-Linked Inhibitor of Apoptosis Protein (XIAP) Is a Nonredundant Modulator of Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL)- Mediated Apoptosis in Human Cancer Cells
Authors: Cummins Jordan M. , Kohli Manu , Rago Carlo , Kinzler Kenneth W. , Vogelstein Bert , Bunz Fred
Published: September 2005

Although the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been shown to play an important role in the immunosurveillance of neoplasia, apoptotic factors that modulate the sensitivity of cancer cells to TRAIL are poorly understood. The inhibitor of apoptosis proteins (IAPs) have generated considerable interest as potential targets for cancer therapy, but the lack of a phenotype in X-linked IAP (XIAP) knockout mice has generated speculation that IAP function may be redundant. Using gene targeting technology, we show that disruption of the gene encoding XIAP in human cancer cells did not interfere with basal proliferation, but caused a remarkable sensitivity to TRAIL. These results demonstrate that XIAP is a nonredundant modulator of TRAIL-mediated apoptosis and provide a rationale for XIAP as a therapeutic target.
Uterine Leiomyomata with t(10;17) Disrupt the Histone Acetyltransferase
MORF
Authors: Moore Steven D. P. , Herrick Steven R. , Ince Tan A. , Kleinman Michael S. , Cin Paola Dal , Morton Cynthia C. , Quade Bradley J.
Published: September 2005

Benign uterine leiomyomata are the most common tumors in women of reproductive age. One recurring chromosomal aberration in uterine leiomyomata is rearrangement of 10q22. Chromosome 10 breakpoints were mapped by fluorescence in situ hybridization to intervals ranging from 8.9 to 72.1 kb within the third intron of MORF (monocytic leukemia zinc finger protein-related factor or MYST4) in four uterine leiomyomata tested. Additional Southern hybridization experiments confirmed that the breakpoint lies within the third intron and narrowed the interval to 2.1 kb in one uterine leiomyomata. MORF is a member of the MYST family of histone acetyltransferase and previously has been found rearranged in some types of acute myeloid leukemia (AML). This is the first instance in which disruption of a histone acetyltransferase has been reported in another tumor type. The breakpoints in uterine leiomyomata would fall in the NH2-terminal portion of the protein between a conserved domain found in histones H1 and H5 and the PHD zinc fingers, the CH2CH zinc finger, or the CoA binding site, which is distinct from the breakpoints reported in AML. Mapping of the 17q21 breakpoint by fluorescence in situ hybridization within a specific region in three tumors revealed several positional candidates including GCN5L2, a gene with histone acetyltransferase activity similar to those fused to MORF in AML. Of note, two of three uterine leiomyomata were of the cellular subtype. Involvement of MORF in four uterine leiomyomata with chromosomal rearrangements involving 10q22 and 17q21 suggests a role for this histone acetyltransferase and altered chromatin regulation in uterine mesenchymal neoplasia.
Steps Involved in Immortalization and Tumorigenesis in Human B-Lymphoblastoid Cell Lines Transformed by Epstein-Barr Virus
Authors: Sugimoto Masanobu , Tahara Hidetoshi , Ide Toshinori , Furuichi Yasuhiro
Published: September 2005

Epstein-Barr virus (EBV) is closely associated with the generation of various tumors, including Burkitt’s lymphoma. Human resting B cells from peripheral blood are easily transformed by EBV to actively proliferating B-lymphoblastoid cell lines (LCLs). These LCLs with normal diploid karyotypes have been believed to be “immortal”, without becoming tumorigenic. A series of recent studies, however, indicate that this initial, simple concept needs extensive reconsideration. Most LCLs from normal individuals are mortal because their telomeres shorten. Some LCLs are truly immortalized by developing strong telomerase activity and aneuploidy, accompanied by various other changes: down-regulation of p16/Rb; mutation of the p53 gene; modulation of apoptosis; and sensitivity to various chemical agents. Some post-immortal LCLs additionally develop the ability to form colonies in agarose and even become tumorigenic by developing the ability to grow in nude mice. The genetic background of LCLs markedly affects the frequency of immortalization. In summary, changes of B cells after infection by EBV are roughly divided into two steps: (a) transformation of B cells into LCLs caused by EBV proteins; and (b) immortalization and tumorigenesis of LCLs mainly regulated by the factors of host cells in cooperation with EBV proteins. The new concept as reviewed here is essential for the future study of tumorigenesis by EBV.
Disruption of Cancer Cell Replication by Alternating Electric Fields
Authors: Kirson Eilon D. , Gurvich Zoya , Schneiderman Rosa , Dekel Erez , Itzhaki Aviran , Wasserman Yoram , Schatzberger Rachel , Palti Yoram
Published: September 2005

Low-intensity, intermediate-frequency (100–300 kHz), alternating electric fields, delivered by means of insulated electrodes, were found to have a profound inhibitory effect on the growth rate of a variety of human and rodent tumor cell lines (Patricia C, U-118, U-87, H-1299, MDA231, PC3, B16F1, F-98, C-6, RG2, and CT-26) and malignant tumors in animals. This effect, shown to be nonthermal, selectively affects dividing cells while quiescent cells are left intact. These fields act in two modes: arrest of cell proliferation and destruction of cells while undergoing division. Both effects are demonstrated when such fields are applied for 24 h to cells undergoing mitosis that is oriented roughly along the field direction. The first mode of action is manifested by interference with the proper formation of the mitotic spindle, whereas the second results in rapid disintegration of the dividing cells. Both effects, which are frequency dependent, are consistent with the computed directional forces exerted by these specific fields on charges and dipoles within the dividing cells. In vivo treatment of tumors in C57BL/6 and BALB/c mice (B16F1 and CT-26 syngeneic tumor models, respectively), resulted in significant slowing of tumor growth and extensive destruction of tumor cells within 3–6 days. These findings demonstrate the potential applicability of the described electric fields as a novel therapeutic modality for malignant tumors.
A Missense Mutation in KIT Kinase Domain 1 Correlates with Imatinib Resistance in Gastrointestinal Stromal Tumors
Authors: Chen Lei L. , Trent Jonathan C. , Wu Elsie F. , Fuller Gregory N. , Ramdas Latha , Zhang Wei , Raymond Austin K. , Prieto Victor G. , Oyedeji Caroline O. , Hunt Kelly K. , Pollock Raphael E. , Feig Barry W. , Hayes Kimberly J. , Choi Haesun , Macapinlac Homer A. , Hittelman Walter , Velasco Marco A. , Patel Shreyaskumar , Burgess Michael A. , Benjamin Robert S. , Frazier Marsha L.
Published: September 2005

KIT gain of function mutations play an important role in the pathogenesis of gastrointestinal stromal tumors (GISTs). Imatinib is a selective tyrosine kinase inhibitor of ABL, platelet-derived growth factor receptor (PDGFR), and KIT and represents a new paradigm of targeted therapy against GISTs. Here we report for the first time that, after imatinib treatment, an additional specific and novel KIT mutation occurs in GISTs as they develop resistance to the drug. We studied 12 GIST patients with initial near-complete response to imatinib. Seven harbored mutations in KIT exon 11, and 5 harbored mutations in exon 9. Within 31 months, six imatinib-resistant rapidly progressive peritoneal implants (metastatic foci) developed in five patients. Quiescent residual GISTs persisted in seven patients. All six rapidly progressive imatinib-resistant implants from five patients show an identical novel KIT missense mutation, 1982T→C, that resulted in Val654Ala in KIT tyrosine kinase domain 1. This novel mutation has never been reported before, is not present in pre-imatinib or post-imatinib residual quiescent GISTs, and is strongly correlated with imatinib resistance. Allelic-specific sequencing data show that this new mutation occurs in the allele that harbors original activation mutation of KIT.
Preexisting Lymphatic Endothelium but not Endothelial Progenitor Cells Are Essential for Tumor Lymphangiogenesis and Lymphatic Metastasis
Authors: He Yulong , Rajantie Iiro , Ilmonen Maritta , Makinen Taija , Karkkainen Marika J. , Haiko Paula , Salven Petri , Alitalo Kari
Published: September 2005

Endothelial progenitor cells have been shown to contribute to angiogenesis in various tumor models. Here, we have studied the relative contributions of bone marrow (BM)-derived endothelial progenitors and pre-existing lymphatic vessels to tumor lymphangiogenesis. We did not find significant incorporation of genetically marked BM-derived cells in lymphatic vessels during tumor- or vascular endothelial growth factor C-induced lymphangiogenesis. The degree of tumor lymphangiogenesis correlated with lymphatic vessel density in the peritumoral area, and despite tumor lymphangiogenesis, lymphatic metastasis failed to occur in gene-targeted vascular endothelial growth factor C+/− mice that have hypoplasia of the lymphatic network. Our data demonstrate that during tumor lymphangiogenesis and cancer cell dissemination via the lymphatics, the newly formed lymphatic vessels sprout from the pre-existing local lymphatic network with little if any incorporation of BM-derived endothelial progenitor cells.
The Biological and Therapeutic Importance of Gastrin Gene Expression in Pancreatic Adenocarcinomas
Authors: Harris Joseph C. , Gilliam Andrew D. , McKenzie Andrew J. , Evans Sean A. , Grabowska Anna M. , Clarke Philip A. , McWilliams Daniel F. , Watson Sue A.
Published: September 2005

The gastrin gene is expressed widely in pancreatic adenocarcinomas and the study aimed to assess its role in both the resistance of cancer cells to apoptosis and the sensitivity of cells to chemotherapeutic agents.

Two human pancreatic cell lines, PAN1 and BXPC3, expressed gastrin at both the RNA and protein levels and are shown to be representative of human pancreatic adenocarcinomas in terms of gastrin expression. Inhibition of endogenous gastrin production by tumor cells was achieved with neutralizing gastrin antiserum and transfection with a gastrin antisense plasmid.

Gastrin antiserum synergized with both taxotere and gemcitabine in inhibiting the in vitro growth of the PAN1 cell line with the inhibitory effect of the antiserum increasing from 12.7% to 70.2% with taxotere (P < 0.05) and 28.6% with gemcitabine (P < 0.01) after controlling for the effects of the cytotoxics. Synergy was only achieved with taxotere in BXPC3 cells with the inhibitory effect of gastrin antiserum increasing from 22.9% to 50.0% (P < 0.005). Cells transfected with gastrin antisense had reduced in vitro growth in low serum conditions and were poorly tumorigenic in nude mice at an orthotopic site. Gastrin antisense-transfected PAN1 cells had increased sensitivity to the antiproliferative effects of both gemcitabine (IC50 of >100 μg/ml reduced to 0.1 μg/ml) and taxotere (IC50 of 20 μg/ml reduced to <0.01 μg/ml) when compared with vector controls. The increased sensitivity of PAN1 antisense coincided with increased caspase-3 activity and reduced protein kinase B/Akt phosphorylation in response to both gemcitabine and taxotere.

Gastrin gene circumvention may be an optimal adjunct to chemotherapeutic agents, such as taxotere and gemcitabine, in pancreatic adenocarcinoma.
Green Fluorescent Protein Tagging of Extracellular Signal-Regulated Kinase and p38 Pathways Reveals Novel Dynamics of Pathway Activation during Primary and Metastatic Growth
Authors: Aguirre-Ghiso Julio A. , Ossowski Liliana , Rosenbaum Sarah K.
Published: September 2005

We describe a novel approach that allows detection of primary and metastatic cells in vivo in which either the extracellular signal-regulated kinase (ERK) or the p38 pathway is activated. Our recent findings showed that ERK and p38 kinases regulate, respectively, programs dictating cell proliferation (high ERK-to-p38 ratio) or growth arrest and dormancy (low ERK-to-p38 ratio) in vivo. Thus, we were able to use green fluorescent protein (GFP) to reflect ERK and p38 activities and, consequently, the proliferative state of cancer cells. This was accomplished by transfecting tumorigenic T-HEp3 and HT1080 cells, and dormant D-HEp3 cells, with plasmids coding for Elk-GAL4 or CHOP-GAL4 fusion proteins that, when phosphorylated by either ERK or p38, respectively, transactivated a GFP-reporter gene. The fate of these cells was examined in culture, in primary sites, and in spontaneous metastasis in chick embryos and nude mice. In culture GFP level was directly proportional to the previously established levels of ERK or p38 activation. In contrast, during the first 24 hours of in vivo inoculation, both the tumorigenic and the dormant cells strongly activated the p38 pathway. However, in the tumorigenic cells, p38 activity was rapidly silenced, correcting the ERK/p38 imbalance and contributing to high ERK activity throughout the entire period of tumor growth. In contrast, in the small nodules formed by dormant cells, the level of ERK activity was dramatically reduced, whereas p38 activity remained high. Strong activation of ERK was evident in metastatic sites, whereas p38 activation was silenced in this anatomic location as well. These results show that it is possible to directly measure cancer cell response to microenvironment with this reporter system and that only proliferation-competent cells have the ability to rapidly adapt ERK and p38 signaling for proliferative success. This approach allows isolation and further characterization of metastatic cells with specific signaling signatures indicative of their phenotypes.
Inhibition of Wnt-1 Signaling Induces Apoptosis in β-Catenin-Deficient Mesothelioma Cells
Authors: You Liang , He Biao , Uematsu Kazutsugu , Xu Zhidong , Mazieres Julien , Lee Amie , McCormick Frank , Jablons David M.
Published: September 2005

It is known that Wnt-1 signaling inhibits apoptosis by activating β-catenin/tcf-mediated transcription. Here, we show that blocking Wnt-1 signaling in β-catenin-deficient mesothelioma cell lines H28 and MS-1 induces apoptotic cell death. Both Wnt-1 small interfering RNA (siRNA) and Dishevelled siRNA induced significant apoptosis in these cell lines. A small molecule inhibitor of c-Jun NH2-terminal kinase inhibited the apoptotic cell killing induced by either Wnt-1 siRNA or Dishevelled siRNA in these cells. Our data suggest that β-catenin-independent noncanonical pathway(s), i.e., Wnt/JNK pathway, may play a role in the apoptotic inhibition caused by Wnt-1 signaling.
Class IV Semaphorins Promote Angiogenesis by Stimulating Rho-Initiated Pathways through Plexin-B
Authors: Basile John R. , Barac Ana , Zhu Tianqing , Guan Kun-Liang , Gutkind J. Silvio
Published: September 2005

The semaphorins are a large family of secreted and cell surface proteins that provide attractive and repulsive cues for axon guidance during neuronal development. Semaphorins share a conserved NH2-terminal Sema domain with their receptors, the plexins, which mediate neuronal cell adhesion, axon guidance, and maintenance of established neuronal pathways in the adult. Both semaphorins and plexins share structural homology with the extracellular domain of c-Met, a member of the scatter factor family of receptors. However, the highly conserved cytoplasmic region of plexins has no homology with the c-Met tyrosine kinase or with any other known protein. Using a recently developed antibody and RNA analysis, we found that high levels of plexin-B1 are expressed in endothelial cells. Whereas c-Met, with which plexin-B1 can interact, is known to be a potent promoter of angiogenesis, the effects of semaphorin-mediated plexin activation in endothelial cells are still poorly understood. Here, we examined the role of plexin-B1 activation in angiogenesis using a purified, secreted form of its ligand, Semaphorin 4D (Sema4D). Sema4D potently induced chemotaxis and tubulogenesis in endothelial cells and enhanced blood vessel formation in an in vivo mouse model. Interestingly, responses to Sema4D did not require c-Met activation. Instead, the use of chimeric plexin-B1 receptors, Rho inhibitors, and lentiviral gene delivery of interfering molecules revealed that these proangiogenic effects are dependent on a COOH-terminal PDZ-binding motif of plexin-B1, which binds two guanine nucleotide exchange factors for the small GTPase Rho, PDZ-RhoGEF and LARG, and are mediated by the activation of Rho-initiated pathways.
Identification of an Active Site on the Laminin α5 Chain Globular Domain That Binds to CD44 and Inhibits Malignancy
Authors: Hibino Suguru , Shibuya Masahiko , Engbring Jean A. , Mochizuki Mayumi , Nomizu Motoyoshi , Kleinman Hynda K.
Published: September 2005

The laminin α5 chain is a component of laminin-10 (α5β1γ1) and -11 (α5β2γ1). In this study, we have screened 113 overlapping synthetic peptides from the laminin α5 globular domain (G-domain) for cell attachment activity with B16-F10 cells using peptide-coated dishes. Eleven attachment-active peptides were identified. In vivo experimental B16-F10 pulmonary metastasis and primary tumor growth assays found that 4 of the 11 peptides inhibited tumor metastasis and growth and increased apoptosis. These four peptides also blocked tumor cell migration, invasion, and angiogenesis. Two of the peptides were highly homologous and showed significant similarity to sequences in collagens. We sought to identify the B16-F10 cell surface receptors for each of the four active peptides using peptide affinity chromatography. Only one peptide recognized a cell surface protein. Peptide A5G27 (RLVSYNGIIFFLK, residues 2892–2904) bound a diffuse Mr ∼120,000–180,000 band that eluted with 2 m NaCl. Glycosidase digestion of the 2 m eluate yielded protein bands of Mr 90,000 and 60,000 that reacted in Western blot analysis with antibodies to CD44. Immunoprecipitation of the A5G27-bound membrane proteins with various cell surface proteoglycan antibodies confirmed CD44 as the surface receptor for A5G27. Finally, attachment assays to A5G27 in the presence of soluble glycosaminoglycans (GAGs) identified the GAGs of CD44 as the binding sites for A5G27. Our results suggest that A5G27 binds to the CD44 receptor of B16-F10 melanoma cells via the GAGs on CD44 and, thus, inhibits tumor cell migration, invasion, and angiogenesis in a dominant-negative manner.
Delivery of Interferon-α Transfected Dendritic Cells into Central Nervous System Tumors Enhances the Antitumor Efficacy of Peripheral Peptide-Based Vaccines
Authors: Okada Hideho , Tsugawa Takahiko , Sato Hidemitsu , Kuwashima Naruo , Gambotto Andrea , Okada Kaori , Dusak Jill E. , Fellows-Mayle Wendy K. , Papworth Glenn D. , Watkins Simon C. , Chambers William H. , Potter Douglas M. , Storkus Walter J. , Pollack Ian F.
Published: September 2005

We evaluated the effects, on immunity and survival, of injection of interferon (IFN)-α-transfected dendritic cells (DC-IFN-α) into intracranial tumors in mice immunized previously with syngeneic dendritic cells (DCs) pulsed either with ovalbumin-derived CTL or T helper epitopes. These immunizations protected animals from s.c. challenge with ovalbumin-expressing M05 melanoma (class I+ and class II-negative). Notably, antiovalbumin CTL responses were observed in animals vaccinated with an ovalbumin-derived T helper epitope but only after the mice were challenged with M05 cells. This cross-priming of CTL was dependent on both CD4+ and CD8+ T cells. Because we observed that s.c., but not intracranial, tumors were infiltrated with CD11c+ DCs, and because IFN-α promotes the activation and survival of both DCs and T cells, we evaluated the combinational antitumor effects of injecting adenoviral (Ad)-IFN-α-engineered DCs into intracranial M05 tumors in preimmunized mice. Delivery of DC-IFN-α prolonged survival. This was most notable for animals prevaccinated with both the CTL and T helper ovalbumin epitopes, with 60% (6 of 10) of mice (versus 0 of 10 of control animals) surviving for >80 days after tumor challenge. DC-IFN-α appeared to persist longer than mock-transfected DCs within the intracranial tumor microenvironment, and DC-IFN-α-treated mice exhibited enhanced levels of ovalbumin-specific CTL in draining cervical lymph nodes. On the basis of these results, we believe that local expression of IFN-α by DCs within the intracranial tumor site may enhance the clinical efficacy of peripheral vaccine approaches for brain tumors.
Targeting Dendritic Cells with Antigen-Containing Liposomes
Authors: van Broekhoven Christina L. , Parish Christopher R. , Demangel Caroline , Britton Warwick J. , Altin Joseph G.
Published: September 2005

Dendritic cells (DCs) are potent stimulators of immunity, and DCs pulsed with tumor antigen ex vivo have applications in tumor immunotherapy. However, DCs are a small population of cells, and their isolation and pulsing with antigen can be impractical. Here we show that a crude preparation of plasma membrane vesicles (PMV) from the highly metastatic murine melanoma (B16-OVA) and a surrogate tumor antigen (OVA) can be targeted directly to DCs in vivo to elicit functional effects. A novel metal-chelating lipid, 3(nitrilotriacetic acid)-ditetradecylamine, was incorporated into B16-OVA-derived PMV, allowing recombinant hexahistidine-tagged forms of single chain antibody fragments to the DC surface molecules CD11c and DEC-205, to be conveniently “engrafted” onto the vesicle surface by metal-chelating linkage. The modified PMV, or similarly engrafted synthetic stealth liposomes containing OVA or OVA peptide antigen, were found to target DCs in vitro and in vivo, in experiments using flow cytometry and fluorescence confocal microscopy. When used as vaccines in syngeneic mice, the preparations stimulated strong B16-OVA-specific CTL responses in splenic T cells and a marked protection against tumor growth. Protection was dependent on the simultaneous delivery of both antigen and a DC maturation or “danger signal” signal (IFN-γ or lipopolysaccharide). Administration of the DC-targeting vaccine to mice challenged with B16-OVA cells induced a dramatic immunotherapeutic effect and prolonged disease-free survival. The results show that the targeting of antigen to DCs in this way is highly effective at inducing immunity and protection against the tumor, with protection being at least partially dependent on the eosinophil chemokine eotaxin.
NIN
, a Gene Encoding a CEP110-Like Centrosomal Protein, Is Fused to
PDGFRB
in a Patient with a t(5;14)(q33;q24) and an Imatinib-Responsive Myeloproliferative Disorder
Authors: Vizmanos José L. , Novo Francisco J. , Román José P. , Baxter E. Joanna , Lahortiga Idoya , Larráyoz María J. , Odero María D. , Giraldo Pilar , Calasanz María J. , Cross Nicholas C. P.
Published: September 2005

We describe a new PDGFRB fusion associated with a t(5;14)(q33;q24) in a patient with a longstanding chronic myeloproliferative disorder with eosinophilia. After confirmation of PDGFRB involvement and definition of the chromosome 14 breakpoint by fluorescence in situ hybridization, candidate partner genes were selected on the basis of the presence of predicted oligomerization domains believed to be an essential feature of tyrosine kinase fusion proteins. We demonstrate that the t(5;14) fuses PDGFRB to NIN, a gene encoding a centrosomal protein with CEP110-like function. After treatment with imatinib, the patient achieved hematological and cytogenetical remission, but NIN-PDGFRB mRNA remained detectable by reverse transcription-PCR.