bluuebunny/crossref_metadata_2025 huggingface dataset:
PPARγ2 Regulates a Molecular Signature of Marrow Mesenchymal Stem Cells
Authors: Shockley K. R. , Rosen C. J. , Churchill G. A. , Lecka-Czernik B.
Published: September 2007

Bone formation and hematopoiesis are anatomically juxtaposed and share common regulatory mechanisms. Bone marrow mesenchymal stromal/stem cells (MSC) contain a compartment that provides progeny with bone forming osteoblasts and fat laden adipocytes as well as fibroblasts, chondrocytes, and muscle cells. In addition, marrow MSC provide an environment for support of hematopoiesis, including the development of bone resorbing osteoclasts. The PPARγ2 nuclear receptor is an adipocyte-specific transcription factor that controls marrow MSC lineage allocation toward adipocytes and osteoblasts. Increased expression of PPARγ2 with aging correlates with changes in the MSC status in respect to both their intrinsic differentiation potential and production of signaling molecules that contribute to the formation of a specific marrow microenvironment. Here, we investigated the effect of PPARγ2 on MSC molecular signature in respect to the expression of gene markers associated exclusively with stem cell phenotype, as well as genes involved in the formation of a stem cell supporting marrow environment. We found that PPARγ2 is a powerful modulator of stem cell-related gene expression. In general, PPARγ2 affects the expression of genes specific for the maintenance of stem cell phenotype, including LIF, LIF receptor, Kit ligand, SDF-1, Rex-1/Zfp42, and Oct-4. Moreover, the antidiabetic PPARγagonist TZD rosiglitazone specifically affects the expression of “stemness” genes, including ABCG2, Egfr, and CD44. Our data indicate that aging and antidiabetic TZD therapy may affect mesenchymal stem cell phenotype through modulation of PPARγ2 activity. These observations may have important therapeutic consequences and indicate a need for more detailed studies of PPARγ2 role in stem cell biology.
Asymptotic Solution of the Theory of Shells Boundary Value Problem
Authors: Andrianov I. V. , Awrejcewicz J.
Published: September 2007

This paper provides a state-of-the-art review of asymptotic methods in the theory of plates and shells. Asymptotic methods of solving problems related to theory of plates and shells have been developed by many authors. The main features of our paper are: (i) it is devoted to the fundamental principles of asymptotic approaches, and (ii) it deals with both traditional approaches, and less widely used, new approaches. The authors have paid special attention to examples and discussion of results rather than to burying the ideas in formalism, notation, and technical details.
A Penalized Linear and Nonlinear Combined Conjugate Gradient Method for the Reconstruction of Fluorescence Molecular Tomography
Authors: Shang Shang , Bai Jing , Song Xiaolei , Wang Hongkai , Lau Jaclyn
Published: September 2007

Conjugate gradient method is verified to be efficient for nonlinear optimization problems of large‐dimension data. In this paper, a penalized linear and nonlinear combined conjugate gradient method for the reconstruction of fluorescence molecular tomography (FMT) is presented. The algorithm combines the linear conjugate gradient method and the nonlinear conjugate gradient method together based on a restart strategy, in order to take advantage of the two kinds of conjugate gradient methods and compensate for the disadvantages. A quadratic penalty method is adopted to gain a nonnegative constraint and reduce the illposedness of the problem. Simulation studies show that the presented algorithm is accurate, stable, and fast. It has a better performance than the conventional conjugate gradient‐based reconstruction algorithms. It offers an effective approach to reconstruct fluorochrome information for FMT.
Existence of Solutions and Convergence of a Multistep Iterative Algorithm for a System of Variational Inclusions with "Equation missing" -Accretive Operators
Authors: Peng Jian-Wen , Zhu Dao-Li , Zheng Xiao-Ping
Published: September 2007

We introduce and study a new system of variational inclusions with "Equation missing"-accretive operators, which contains variational inequalities, variational inclusions, systems of variational inequalities, and systems of variational inclusions in the literature as special cases. By using the resolvent technique for the "Equation missing"-accretive operators, we prove the existence and uniqueness of solution and the convergence of a new multistep iterative algorithm for this system of variational inclusions in real "Equation missing"-uniformly smooth Banach spaces. The results in this paper unify, extend, and improve some known results in the literature.
Complexes of Pd(II) and Pt(II) with 9-Aminoacridine: Reactions with DNA and Study of Their Antiproliferative Activity
Authors: Riera X. , Moreno V. , Ciudad C. J. , Noe V. , Font-Bardía M. , Solans X.
Published: September 2007

Four new metal complexes {M = Pd(II) or Pt(II)} containing the ligand 9-aminoacridine (9AA) were prepared. The compounds were characterized by FT-IR andH,C, andPtNMR spectroscopies. Crystal structure of the palladium complex of formulae[Pd(9AA)(μ-Cl)]2·2DMF was determined by X-ray diffraction. Two 9-acridine molecules in the imine form bind symmetrically to the metal ions in a bidentate fashion through the imine nitrogen atom and the C(1) atom of the aminoacridine closing a new five-membered ring. By reaction with phosphine or pyridine, the Cl bridges broke and compounds with general formulae [Pd(9AA)Cl(L)] (whereL=PPh3or py) were formed. A mononuclear complex of platinum of formulae [Pt(9AA)Cl(DMSO)] was also obtained by direct reaction of 9-aminoacridine and the complex [PtCl2(DMSO)2]. The capacity of the compounds to modify the secondary and tertiary structures of DNA was evaluated by means of circular dichroism and electrophoretic mobility. Both palladium and platinum compounds proved active in the modification of both the secondary and tertiary DNA structures. AFM images showed noticeable modifications of the morphology of the plasmid pBR322 DNA by the compounds probably due to the intercalation of the complexes between base pairs of the DNA molecule. Finally, the palladium complex was tested for antiproliferative activity against three different human tumor cell lines. The results suggest that the palladium complex of formula[Pd(9AA)(μ-Cl)]2has significant antiproliferative activity, although it is less active than cisplatin.
Foxp3 Expression in Pancreatic Carcinoma Cells as a Novel Mechanism of Immune Evasion in Cancer
Authors: Hinz Sebastian , Pagerols-Raluy Laia , Oberg Hans-Heinrich , Ammerpohl Ole , Grüssel Sandra , Sipos Bence , Grützmann Robert , Pilarsky Christian , Ungefroren Hendrik , Saeger Hans-Detlev , Klöppel Günter , Kabelitz Dieter , Kalthoff Holger
Published: September 2007

The forkhead transcription factor Foxp3 is highly expressed in CD4+CD25+ regulatory T cells (Treg) and was recently identified as a key player in mediating their inhibitory functions. Here, we describe for the first time the expression and function of Foxp3 in pancreatic ductal adenocarcinoma cells and tumors. Foxp3 expression was induced by transforming growth factor-β2 (TGF-β2), but not TGF-β1 stimulation in these cells, and was partially suppressed following antibody-mediated neutralization of TGF-β2. The TGF-β2 effect could be mimicked by ectopic expression of a constitutively active TGF-β type I receptor/ALK5 mutant. Down-regulation of Foxp3 with small interfering RNA (siRNA) in pancreatic carcinoma cells resulted in the up-regulation of interleukin 6 (IL-6) and IL-8 expression, providing evidence for a negative transcriptional activity of Foxp3 also in these epithelial cells. Coculture of Foxp3-expressing tumor cells with naive T cells completely inhibited T-cell proliferation, but not activation, and this antiproliferative effect was partially abrogated following specific inhibition of Foxp3 expression. These findings indicate that pancreatic carcinoma cells share growth-suppressive effects with Treg and suggest that mimicking Treg function may represent a new mechanism of immune evasion in pancreatic cancer. [Cancer Res 2007;67(17):8344–50]
Expression of a CALM-AF10 Fusion Gene Leads to Hoxa Cluster Overexpression and Acute Leukemia in Transgenic Mice
Authors: Caudell David , Zhang Zhenhua , Chung Yang Jo , Aplan Peter D.
Published: September 2007

To assess the role of the CALM-AF10 fusion gene in leukemic transformation in vivo, we generated transgenic mice that expressed a CALM-AF10 fusion gene. Depending on the transgenic line, at least 40% to 50% of the F1 generation mice developed acute leukemia at a median age of 12 months. Leukemic mice typically had enlarged spleens, invasion of parenchymal organs with malignant cells, and tumors with myeloid markers such as myeloperoxidase, Mac1, and Gr1. Although most leukemias were acute myeloid leukemia, many showed lymphoid features, such as CD3 staining, or clonal Tcrb or Igh gene rearrangements. Mice were clinically healthy for the first 9 months of life and had normal peripheral blood hemograms but showed impaired thymocyte differentiation, manifested by decreased CD4+/CD8+ cells and increased immature CD4−/CD8− cells in the thymus. Hematopoietic tissues from both clinically healthy and leukemic CALM-AF10 mice showed up-regulation of Hoxa cluster genes, suggesting a potential mechanism for the impaired differentiation. The long latency period and incomplete penetrance suggest that additional genetic events are needed to complement the CALM-AF10 transgene and complete the process of leukemic transformation. [Cancer Res 2007;67(17):8022–31]
Antitumor Effect of Antibody against a SEREX-Defined Antigen (UOEH-LC-1) on Lung Cancer Xenotransplanted into Severe Combined Immunodeficiency Mice
Authors: Mizukami Makiko , Hanagiri Takeshi , Yasuda Manabu , Kuroda Koji , Shigematsu Yoshiki , Baba Tetsuro , Fukuyama Takashi , Nagata Yoshika , So Tetsuya , Ichiki Yoshinobu , Sugaya Masakazu , So Tomoko , Takenoyama Mitsuhiro , Sugio Kenji , Yasumoto Kosei
Published: September 2007

We previously reported the humoral immune response of tumor-infiltrating B lymphocytes in a lung cancer patient and 22 genes coding tumor-associated antigens identified using the serological identification of antigens by recombinant expression cloning method. In this study, we investigated one of these genes, designated University of Occupational and Environmental Health—Lung cancer antigen-1 (UOEH-LC-1), which has an extracellular domain. Quantitative reverse transcription-PCR revealed that UOEH-LC-1 was expressed ubiquitously in the normal tissues tested. However, it was overexpressed in 5 of 11 (45.5%) lung cancer cell lines and also in 9 of 15 (60%) lung cancer tissues compared with the paired normal lung tissues. A sequence analysis revealed that UOEH-LC-1 has a transmembrane domain. Flow cytometry analysis using a polyclonal antibody against UOEH-LC-1 revealed positive staining on lung cancer cell lines that were positive for expression of mRNA of UOEH-LC-1. Phage plaque assay showed the specific reactivity of anti–UOEH-LC-1 antibody against UOEH-LC-1 protein derived from the antigen encoding phage. By immunohistochemical staining with the anti–UOEH-LC-1 antibody, 7 of 28 (25.0%) lung cancer specimens showed positive staining on the cell surface. The administration of anti–UOEH-LC-1 antibody inhibited the growth of the UOEH-LC-1–positive tumors that were xenotransplanted into severe combined immunodeficiency mice. Complement-dependent cytotoxicity was one of the mechanisms to suppress the tumor growth. These results suggest that the antibody against UOEH-LC-1 therefore seems to have a promising therapeutic potential as a treatment for lung cancer. [Cancer Res 2007;67(17):8351–7]
Inhibition of Prostate Cancer Growth by Muscadine Grape Skin Extract and Resveratrol through Distinct Mechanisms
Authors: Hudson Tamaro S. , Hartle Diane K. , Hursting Stephen D. , Nunez Nomeli P. , Wang Thomas T.Y. , Young Heather A. , Arany Praveen , Green Jeffrey E.
Published: September 2007

The phytochemical resveratrol contained in red grapes has been shown to inhibit prostate cancer cell growth, in part, through its antioxidant activity. Muscadine grapes contain unique phytochemical constituents compared with other grapes and are potentially a source for novel compounds with antitumor activities. We compared the antitumor activities of muscadine grape skin extract (MSKE), which we show contains no resveratrol, with that of resveratrol using primary cultures of normal prostate epithelial cells (PrEC) and the prostate cancer cell lines RWPE-1, WPE1-NA22, WPE1-NB14, and WPE1-NB26, representing different stages of prostate cancer progression. MSKE significantly inhibited tumor cell growth in all transformed prostate cancer cell lines but not PrEC cells. Prostate tumor cell lines, but not PrEC cells, exhibited high rates of apoptosis in response to MSKE through targeting of the phosphatidylinositol 3-kinase–Akt and mitogen-activated protein kinase survival pathways. The reduction in Akt activity by MSKE is mediated through a reduction in Akt transcription, enhanced proteosome degradation of Akt, and altered levels of DJ-1, a known regulator of PTEN. In contrast to MSKE, resveratrol did not induce apoptosis in this model but arrested cells at the G1-S phase transition of the cell cycle associated with increased expression of p21 and decreased expression of cyclin D1 and cyclin-dependent kinase 4 proteins. These results show that MSKE and resveratrol target distinct pathways to inhibit prostate cancer cell growth in this system and that the unique properties of MSKE suggest that it may be an important source for further development of chemopreventive or therapeutic agents against prostate cancer. [Cancer Res 2007;67(17):8396–405]
Inactivation of Smad4 Accelerates KrasG12D-Mediated Pancreatic Neoplasia
Authors: Kojima Kyoko , Vickers Selwyn M. , Adsay N. Volkan , Jhala Nirag C. , Kim Hyung-Gyoon , Schoeb Trenton R. , Grizzle William E. , Klug Christopher A.
Published: September 2007

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal human malignancies, with an overall 5-year survival rate of <5%. Genetic analysis of PDAC patient samples has shown that specific disease-associated mutations are correlated with histologically defined stages of neoplastic progression in the ductal epithelium. Activating mutations in KRAS are almost uniformly present in early-stage disease, with subsequent inactivating mutations in p16INK4A, p53, and SMAD4 occurring in more advanced lesions. In this study, we have tested whether the loss of Smad4 would cooperate with an activating KrasG12D mutation to promote progression to PDAC using the Pdx1-Cre transgenic system to activate KrasG12D and delete Smad4 in all pancreatic lineages including the ductal epithelium. Analysis of double-mutant mice showed that loss of Smad4 significantly accelerated the progression of pancreatic intraepithelial neoplasias (mPanIN) and promoted a high incidence of intraductal papillary mucinous neoplasia and active fibrosis compared with Pdx1-Cre;KrasG12D or Pdx1-Cre;Smad4lox/lox mice. Occasionally, double-mutant mice progressed to locally invasive PDAC with little evidence of metastases by 6 months of age and without the detectable loss of p53 or p16Ink4A expression or function. The loss of Smad4 only seemed to promote disease progression in the presence of the activated KrasG12D allele because we observed no abnormal pathology within the pancreata of 23 Pdx1-Cre;Smad4lox/lox animals that were analyzed up to 8 months of age. This indicates that Smad4 is dispensable for normal pancreatic development but is critical for at least partial suppression of multiple KrasG12D-dependent disease-associated phenotypes. [Cancer Res 2007;67(17):8121–30]
Gene-Engineered Varicella-Zoster Virus–Reactive CD4+ Cytotoxic T Cells Exert Tumor-Specific Effector Function
Authors: Landmeier Silke , Altvater Bianca , Pscherer Sibylle , Eing Bodo R. , Kuehn Joachim , Rooney Cliona M. , Juergens Heribert , Rossig Claudia
Published: September 2007

T cells with grafted specificities for surface antigens provide an avenue for rapidly producing immune effector cells with tumor specificity. However, the function of chimeric receptor (chRec) gene-modified T cells is limited by lack of T-cell expansion and persistence. We propose to use varicella zoster virus (VZV)–reactive T cells as host for the chRec because these cells can be expanded both in vitro and in vivo by stimulation of their native receptor during endogenous reexposure to the virus or by administration of VZV vaccine. We obtained human T cells reactive with VZV from the peripheral blood of seropositive donors by stimulation with VZV lysate and evaluated their characteristics after genetic modification with two tumor-specific model chRecs. Cultures dominated by cytolytic CD4+ T cells (VZV-CTL) could be expanded and maintained in vitro. Gene-modified VZV-CTL recognized and lysed tumor targets in a MHC-independent manner while maintaining functional, MHC-restricted interaction with VZV antigen through their native receptor. Thus, chRec-transduced VZV-CTL may provide a source of potent tumor-reactive cells for adoptive immunotherapy of cancer. The availability of a safe and effective VZV vaccine provides the option of repeated in vivo stimulation to maintain high T-cell numbers until the tumor is eliminated. [Cancer Res 2007;67(17):8335–43]
Bone Morphogenetic Protein Signaling Suppresses Tumorigenesis at Gastric Epithelial Transition Zones in Mice
Authors: Bleuming Sylvia A. , He Xi C. , Kodach Liudmila L. , Hardwick James C. , Koopman Frieda A. , ten Kate Fiebo J. , van Deventer Sander J.H. , Hommes Daniel W. , Peppelenbosch Maikel P. , Offerhaus G. Johan , Li Linheng , van den Brink Gijs R.
Published: September 2007

Bone morphogenetic protein (BMP) signaling is known to suppress oncogenesis in the small and large intestine of mice and humans. We examined the role of Bmpr1a signaling in the stomach. On conditional inactivation of Bmpr1a, mice developed neoplastic lesions specifically in the squamocolumnar and gastrointestinal transition zones. We hypothesized that the regulation of epithelial cell fate may be less well defined in these junctional zones than in the adjacent epithelium and found that the mucosa at the squamocolumnar junction in mice shows a lack of differentiated fundic gland cell types and that foveolar cells at the gastrointestinal junctional zone lack expression of the foveolar cell marker Muc5ac. Precursor cell proliferation in both transition zones was higher than in the surrounding epithelium. Our data show that BMP signaling through Bmpr1a suppresses tumorigenesis at gastric epithelial junctional zones that are distinct from the adjacent gastric epithelium in both cellular differentiation and proliferation. [Cancer Res 2007;67(17):8149–55]
ICOVIR-5 Shows E2F1 Addiction and Potent Antiglioma Effect In vivo
Authors: Alonso Marta M. , Cascallo Manel , Gomez-Manzano Candelaria , Jiang Hong , Bekele B. Nebiyou , Perez-Gimenez Anna , Lang Frederick F. , Piao Yuji , Alemany Ramon , Fueyo Juan
Published: September 2007

During 2007, ∼200,000 people in the United States will be diagnosed with brain tumors. Gliomas account for 77% of primary malignant brain tumors, and the prognosis has hardly changed in the past 20 years, with only 30% of patients with malignant glioma surviving 5 years after diagnosis. Oncolytic adenoviruses are promising therapies for the treatment of gliomas. Here, report the antiglioma activity of the tumor-selective ICOVIR-5 adenovirus, which encompasses an early 1A adenoviral (E1A) deletion in the retinoblastoma (Rb) protein-binding region, substitution of the E1A promoter for E2F-responsive elements, and an RGD-4C peptide motif inserted into the adenoviral fiber to enhance adenoviral tropism. Mechanistic studies showed a dramatic addiction of ICOVIR-5 to the E2F1 oncogene in vitro and in vivo. This addiction was mediated by the occupancy of the ectopic adenoviral E2F1-responsive elements by the endogenous E2F1 protein resulting in high level of E1A expression in cancer cells and potent antiglioma effect. Importantly, we showed for the first time the ability of oncolytic adenoviruses to enhance E2F transcriptional activity in vivo, and we provided direct evidence of the interaction of the E2F1 protein with native and ectopic adenovirus promoters. Restoration of Rb function led to the association of Rb/E2F1 repressor complexes with ICOVIR-5 ectopic E2F1 promoter and subsequent down-modulation of E1A, dramatically impairing adenoviral replication. In xenografted mice, intratumoral injection of ICOVIR-5 resulted in a significant improvement of the median survival (P < 0.0001), and furthermore, led to 37% of long-term survivors free of disease. The antitumor activity of ICOVIR-5 suggests that it has the potential to be an effective agent in the treatment of gliomas. [Cancer Res 2007;67(17):8255–63]
Retinoblastoma Deficiency Increases Chemosensitivity in Lung Cancer
Authors: Zagorski William A. , Knudsen Erik S. , Reed Michael F.
Published: September 2007

The retinoblastoma (RB) tumor suppressor is mutated or functionally inactivated in the majority of human malignancies, and p16INK4a-cyclin D1-cyclin-dependent kinase 4-RB pathway aberrations are present in nearly all cases of non–small cell lung cancer (NSCLC). Here, the distinct role of RB loss in tumorigenic proliferation and sensitivity to chemotherapeutics was determined in NSCLC cells. Attenuation of RB led to a proliferative advantage in vitro and aggressive tumorigenic growth in xenograft models. Clinically, such aggressive disease is treated with genotoxic and cytotoxic chemotherapeutic agents. In vitro analysis showed that RB deficiency resulted in bypass of the checkpoint response to multiple chemotherapeutic challenges concomitant with an elevated apoptotic response. Correspondingly, RB deficiency in xenograft models led to increased chemosensitivity. However, this response was transient, and a durable response was dependent on prolonged chemotherapeutic administration. Together, these findings show that although RB deficiency enhances sensitivity to chemotherapeutic challenge, efficient and sustainable response is highly dependent on the specific therapeutic regimen, in addition to the molecular environment. [Cancer Res 2007;67(17):8264–73]
Dendrimer-Modified Magnetic Nanoparticles Enhance Efficiency of Gene Delivery System
Authors: Pan Bifeng , Cui Daxiang , Sheng Yuan , Ozkan Cengiz , Gao Feng , He Rong , Li Qing , Xu Ping , Huang Tuo
Published: September 2007

Magnetic nanoparticles (MNP) with a diameter of 8 nm were modified with different generations of polyamidoamine (PAMAM) dendrimers and mixed with antisense survivin oligodeoxynucleotide (asODN). The MNP then formed asODN-dendrimer-MNP composites, which we incubated with human tumor cell lines such as human breast cancer MCF-7, MDA-MB-435, and liver cancer HepG2 and then analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, quantitative reverse transcription-PCR, Western blotting, laser confocal microscopy, and high-resolution transmission electron microscopy. Results showed that the asODN-dendrimer-MNP composites were successfully synthesized, can enter into tumor cells within 15 min, caused marked down-regulation of the survivin gene and protein, and inhibited cell growth in dose- and time-dependent means. No.5 generation of asODN-dendrimer-MNP composites exhibits the highest efficiency for cellular transfection and inhibition. These results show that PAMAM dendrimer-modified MNPs may be a good gene delivery system and have potential applications in cancer therapy and molecular imaging diagnosis. [Cancer Res 2007;67(17):8156–63]
Seizure 6-Like (SEZ6L) Gene and Risk for Lung Cancer
Authors: Gorlov Ivan P. , Meyer Peter , Liloglou Triantafillos , Myles Jonathan , Boettger Melanie Barbara , Cassidy Adrian , Girard Luc , Minna John D. , Fischer Reiner , Duffy Stephen , Spitz Margaret R. , Haeussinger Karl , Kammerer Stefan , Cantor Charles , Dierkesmann Rainer , Field John K. , Amos Christopher I.
Published: September 2007

DNA pooling in combination with high-throughput sequencing was done as a part of the Sequenom-Genefinder project. In the pilot study, we tested 83,715 single nucleotide polymorphisms (SNP), located primarily in gene-based regions, to identify polymorphic susceptibility variants for lung cancer. For this pilot study, 369 male cases and 287 controls of both sexes (white Europeans of Southern German origin) were analyzed. The study identified a candidate region in 22q12.2 that contained numerous SNPs showing significant case-control differences and that coincides with a region that was shown previously to be frequently deleted in lung cancer cell lines. The candidate region overlies the seizure 6-like (SEZ6L) gene. The pilot study identified a polymorphic Met430Ile substitution in the SEZ6L gene (SNP rs663048) as the top candidate for a variant modulating risk of lung cancer. Two replication studies were conducted to assess the association of SNP rs663048 with lung cancer risk. The M. D. Anderson Cancer Center study included 289 cases and 291 controls matched for gender, age, and smoking status. The Liverpool Lung Project (a United Kingdom study) included 248 cases and 233 controls. Both replication studies showed an association of the rs663048 with lung cancer risk. The homozygotes for the variant allele had more than a 3-fold risk compared with the wild-type homozygotes [combined odds ratio (OR), 3.32; 95% confidence interval (95% CI), 1.81–7.21]. Heterozygotes also had a significantly elevated risk of lung cancer from the combined replication studies with an OR of 1.15 (95% CI, 1.04–1.59). The effect remained significant after adjusting for age, gender, and pack-years of tobacco smoke. We also compared expression of SEZ6L in normal human bronchial epithelial cells (n = 7), non–small cell lung cancer (NSCLC; n = 52), and small cell lung cancer (SCLC; n = 22) cell lines by using Affymetrix HG-U133A and HG-U133B GeneChips. We found that the average expression level of SEZ6L in NSCLC cell lines was almost two times higher and in SCLC cell lines more than six times higher when compared with normal lung epithelial cell lines. Using the National Center for Biotechnology Information Gene Expression Omnibus database, we found a ∼2-fold elevated and statistically significant (P = 0.004) level of SEZ6L expression in tumor samples compared with normal lung tissues. In conclusion, the results of these studies representing 906 cases compared with 811 controls indicate a role of the SEZ6L Met430Ile polymorphic variant in increasing lung cancer risk. [Cancer Res 2007;67(17):8406–11]
Identifying the Estrogen Receptor Coactivator PELP1 in Autophagosomes
Authors: Ohshiro Kazufumi , Rayala Suresh K. , Kondo Seiji , Gaur Amitabh , Vadlamudi Ratna K. , El-Naggar Adel K. , Kumar Rakesh
Published: September 2007

Resveratrol, a well-established phytoestrogen and chemopreventive agent, has gained much attention among oncologists because it can act as both estrogen receptor agonist and antagonist, depending on dosage and cell context. It is increasingly accepted that steroidal receptor coregulators may also function in the cytoplasmic compartment. Deregulation and altered localization of these coregulators could influence target gene expression and participate in the development of hormone-responsive cancers. Proline-, glutamic acid–, and leucine-rich protein-1 (PELP1), a novel estrogen receptor (ER) coactivator, plays an important role in the genomic and nongenomic actions of ER. Furthermore, recent studies have shown that differential compartmentalization of PELP1 could be crucial in modulating sensitivity to tamoxifen. In this study, we investigated the role of PELP1 in resveratrol-induced autophagy in lung cancer and salivary gland adenocarcinoma cell lines. Resveratrol reversibly inhibited the growth of these cancer cell lines and induced autophagy, as evidenced by microtubule-associated protein 1 light chain 3 (LC3) up-regulation in a time-dependent and 3-methyladenine–sensitive manner. Confocal microscopic analysis showed that resveratrol induced PELP1 accumulation in autophagosomes with green fluorescent protein-LC3. The intermediary molecule involved in PELP1 accumulation in resveratrol-induced autophagosomes is hepatocyte growth factor–regulated tyrosine kinase substrate (HRS), a trafficking molecule that binds to PELP1. These results identify PELP1 for the first time in autophagosomes, implying that both PELP1 and HRS reallocate to autophagosomes in response to resveratrol treatment, which might be important in the process of autophagy in the cancer cells. [Cancer Res 2007;67(17):8164–71]
Increased Expression of the E3 Ubiquitin Ligase RNF5 Is Associated with Decreased Survival in Breast Cancer
Authors: Bromberg Kenneth D. , Kluger Harriet M. , Delaunay Agnes , Abbas Sabiha , DiVito Kyle A. , Krajewski Stan , Ronai Ze'ev
Published: September 2007

The selective ubiquitination of proteins by ubiquitin E3 ligases plays an important regulatory role in control of cell differentiation, growth, and transformation and their dysregulation is often associated with pathologic outcomes, including tumorigenesis. RNF5 is an E3 ubiquitin ligase that has been implicated in motility and endoplasmic reticulum stress response. Here, we show that RNF5 expression is up-regulated in breast cancer tumors and related cell lines. Elevated expression of RNF5 was seen in breast cancer cell lines that became more sensitive to cytochalasin D– and paclitaxel-induced apoptosis following its knockdown with specific short interfering RNA. Inhibition of RNF5 expression markedly decreased cell proliferation and caused a reorganization of the actin cytoskeleton in response to stress in MCF-7 but not in p53 mutant breast cancer cells, suggesting a p53-dependent function. Significantly, high levels of RNF5 were associated with decreased survival in human breast cancer specimens. Similarly, RNF5 levels were higher in metastatic melanoma specimens and in melanoma, leukemia, ovarian, and renal tumor-derived cell lines, suggesting that increased RNF5 expression may be a common event during tumor progression. These results indicate that RNF5 is a novel regulator of breast cancer progression through its effect on actin cytoskeletal alterations, which also affect sensitivity of breast cancer cells to cytoskeletal targeting antineoplastic agents. [Cancer Res 2007;67(17):8172–9]
Genetic Screening Reveals an Essential Role of p27kip1 in Restriction of Breast Cancer Progression
Authors: Yuan Yuhui , Qin Li , Liu Dan , Wu Ray-Chang , Mussi Paola , Zhou Suoling , Songyang Zhou , Xu Jianming
Published: September 2007

The genetic changes and mechanisms underlying the progression of estrogen-dependent breast cancers to estrogen-independent, antiestrogen-resistant, and metastatic breast cancers are unclear despite being a major problem in endocrine therapy. To identify genes responsible for this progression, we carried out a genetic screening by an enhanced retroviral mutagen (ERM)–mediated random mutagenesis in the estrogen-dependent T47D breast cancer cells. We found that T47D cells contain only one p27kip1 (p27) allele coding for the p27 cyclin-dependent kinase (CDK) inhibitor. An ERM insertion into the p27 locus of T47D cells disrupted the p27 gene and created estrogen-independent and antiestrogen-resistant breast cancer cells that still maintained functional estrogen receptors. Disruption of p27 in T47D cells resulted in several changes, and most of these changes could be rescued by p27 restoration. First, CDK2 activity was increased in the absence of estrogen or in the presence of estrogen antagonists tamoxifen or ICI 182780; second, amplified in breast cancer 1 (AIB1), a cancer overexpressed transcriptional coactivator, was hyperphosphorylated, which made AIB1 a better coactivator for E2F1; and third, growth factor receptor binding protein 2–associated binder 2 (Gab2) and Akt activity were increased following E2F1 overactivation, leading to a significant enhancement of cell migration and invasion. Furthermore, the p27-deficient cells, but not T47D control cells, developed lung metastasis in an ovarian hormone–independent manner when they were i.v. injected into nude mice. In sum, loss of p27 activated AIB1, E2F1, Gab2, and Akt; increased cell migration and invasion; caused antiestrogen insensitivity; and promoted metastasis of breast cancer cells. These findings suggest that p27 plays an essential role in restriction of breast cancer progression. [Cancer Res 2007;67(17):8032–42]
Chemical Inhibition of Acetyl-CoA Carboxylase Induces Growth Arrest and Cytotoxicity Selectively in Cancer Cells
Authors: Beckers Annelies , Organe Sophie , Timmermans Leen , Scheys Katryn , Peeters Annelies , Brusselmans Koen , Verhoeven Guido , Swinnen Johannes V.
Published: September 2007

Development and progression of cancer is accompanied by marked changes in the expression and activity of enzymes involved in the cellular homeostasis of fatty acids. One class of enzymes that play a particularly important role in this process are the acetyl-CoA carboxylases (ACC). ACCs produce malonyl-CoA, an intermediate metabolite that functions as substrate for fatty acid synthesis and as negative regulator of fatty acid oxidation. Here, using the potent ACC inhibitor soraphen A, a macrocyclic polyketide from myxobacteria, we show that ACC activity in cancer cells is essential for proliferation and survival. Even at nanomolar concentrations, soraphen A can block fatty acid synthesis and stimulate fatty acid oxidation in LNCaP and PC-3M prostate cancer cells. As a result, the phospholipid content of cancer cells decreased, and cells stopped proliferating and ultimately died. LNCaP cells predominantly died through apoptosis, whereas PC-3M cells showed signs of autophagy. Supplementation of the culture medium with exogenous palmitic acid completely abolished the effects of soraphen A and rescued the cells from cell death. Interestingly, when added to cultures of premalignant BPH-1 cells, soraphen A only slightly affected cell proliferation and did not induce cell death. Together, these findings indicate that cancer cells have become dependent on ACC activity to provide the cell with a sufficient supply of fatty acids to permit proliferation and survival, introducing the concept of using small-molecule ACC inhibitors as therapeutic agents for cancer. [Cancer Res 2007;67(17):8180–7]
Kallikrein 6 Induces E-Cadherin Shedding and Promotes Cell Proliferation, Migration, and Invasion
Authors: Klucky Britta , Mueller Regina , Vogt Ingeborg , Teurich Sibylle , Hartenstein Bettina , Breuhahn Kai , Flechtenmacher Christa , Angel Peter , Hess Jochen
Published: September 2007

Recently, we described phorbol ester–induced expression of the brain and skin serine proteinase Bssp/kallikrein 6 (Klk6), the mouse orthologue of human KLK6, in mouse back skin and in advanced tumor stages of a well-established multistage tumor model. Here, we show KLK6 up-regulation in squamous skin tumors of human patients and in tumors of other epithelial tissues. Ectopic Klk6 expression in mouse keratinocyte cell lines induces a spindle-like morphology associated with accelerated proliferation, migration, and invasion capacity. We found reduced E-cadherin protein levels in the cell membrane and nuclear translocation of β-catenin in Klk6-expressing mouse keratinocytes and human HEK293 cells transfected with a KLK6 expression plasmid. Additionally, HEK293 cells exhibited induced T-cell factor–dependent transcription and impaired cell-cell adhesion in the presence of KLK6, which was accompanied by induced E-cadherin ectodomain shedding. Interestingly, tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-3 interfere with KLK6-induced E-cadherin ectodomain shedding and rescue the cell-cell adhesion defect in vitro, suggesting the involvement of matrix metalloproteinase and/or a disintegrin and metalloproteinase (ADAM) proteolytic activity. In line with this assumption, we found increased levels of the mature 62-kDa ADAM10 proteinase in cells expressing ectopic KLK6 compared with mock controls. Finally, enhanced epidermal keratinocyte proliferation and migration in concert with decreased E-cadherin protein levels are confirmed in an in vivo Klk6 transgenic mouse model. [Cancer Res 2007;67(17):8198–206]
5-Azacytidine–Induced Methyltransferase-DNA Adducts Block DNA Replication In vivo
Authors: Kuo H. Kenny , Griffith Jack D. , Kreuzer Kenneth N.
Published: September 2007

5-Azacytidine (aza-C) and its derivatives are cytidine analogues used for leukemia chemotherapy. The primary effect of aza-C is the prohibition of cytosine methylation, which results in covalent methyltransferase-DNA (MTase-DNA) adducts at cytosine methylation sites. These adducts have been suggested to cause chromosomal rearrangements and contribute to cytotoxicity, but the detailed mechanisms have not been elucidated. We used two-dimensional agarose gel electrophoresis and electron microscopy to analyze plasmid pBR322 replication dynamics in Escherichia coli cells grown in the presence of aza-C. Two-dimensional gel analysis revealed the accumulation of specific bubble and Y molecules, dependent on overproduction of the cytosine MTase EcoRII (M.EcoRII) and treatment with aza-C. Furthermore, a point mutation that eliminates a particular EcoRII methylation site resulted in disappearance of the corresponding bubble and Y molecules. These results imply that aza-C–induced MTase-DNA adducts block DNA replication in vivo. RecA-dependent X structures were also observed after aza-C treatment. These molecules may be generated from blocked forks by recombinational repair and/or replication fork regression. In addition, electron microscopy analysis revealed both bubbles and rolling circles (RC) after aza-C treatment. These results suggest that replication can switch from theta to RC mode after a replication fork is stalled by an MTase-DNA adduct. The simplest model for the conversion of theta to RC mode is that the blocked replication fork is cleaved by a branch-specific endonuclease. Such replication-dependent DNA breaks may represent an important pathway that contributes to genome rearrangement and/or cytotoxicity. [Cancer Res 2007;67(17):8248–54]
Overexpression of the MicroRNA hsa-miR-200c Leads to Reduced Expression of Transcription Factor 8 and Increased Expression of E-Cadherin
Authors: Hurteau Gregory J. , Carlson J. Andrew , Spivack Simon D. , Brock Graham J.
Published: September 2007

MicroRNAs are ∼22-nucleotide sequences thought to interact with multiple mRNAs resulting in either translational repression or degradation. We previously reported that several microRNAs had variable expression in mammalian cell lines, and we examined one, miR-200c, in more detail. A combination of bioinformatics and quantitative reverse transcription-PCR was used to identify potential targets and revealed that the zinc finger transcription factor transcription factor 8 (TCF8; also termed ZEB1, δEF1, Nil-2-α) had inversely proportional expression levels to miR-200c. Knockout experiments using anti-microRNA oligonucleotides increased TCF8 levels but with nonspecific effects. Therefore, to investigate target predictions, we overexpressed miR-200c in select cells lines. Ordinarily, the expression level of miR-200c in non–small-cell lung cancer A549 cells is low in contrast to normal human bronchial epithelial cells. Stable overexpression of miR-200c in A549 cells results in a loss of TCF8, an increase in expression of its regulatory target, E-cadherin, and altered cell morphology. In MCF7 (estrogen receptor–positive breast cancer) cells, there is endogenous expression of miR-200c and E-cadherin but TCF8 is absent. Conversely, MDA-MB-231 (estrogen receptor–negative) cells lack detectable miR-200c and E-cadherin (the latter reportedly due to promoter region methylation) but express TCF8. The ectopic expression of miR-200c in this cell line also reduced levels of TCF8, restored E-cadherin expression, and altered cell morphology. Because the down-regulation of E-cadherin is a crucial event in epithelial-to-mesenchymal transition, loss of miR-200c expression could play a significant role in the initiation of an invasive phenotype, and, equally, miR-200c overexpression holds potential for its reversal. [Cancer Res 2007;67(17):7972–6]
Oxygen Concentration Determines the Biological Effects of NOTCH-1 Signaling in Adenocarcinoma of the Lung
Authors: Chen Yuanbin , De Marco Melissa A. , Graziani Irene , Gazdar Adi F. , Strack Peter R. , Miele Lucio , Bocchetta Maurizio
Published: September 2007

NOTCH signaling is an evolutionarily conserved signaling pathway that regulates cell fate during development and postnatal life. It has been increasingly linked to carcinogenesis, although its role in cancer seems to be highly context and tissue specific. Although NOTCH signaling is required for lung development, little is known about its role in lung cancer. In this study, we show that NOTCH signaling, as measured by the γ-secretase cleavage product NIC-1, is active in both normal human and lung tumor samples; however, downstream NOTCH readouts (i.e., HES-1 and HES-5) are elevated in lung tumors. Levels of NOTCH signaling components in primary human lung cells reflect observations in tissue samples, yet lung tumor cell lines showed little NOTCH signaling. Because oxygen concentrations are important in normal lung physiology and lung tumors are hypoxic, the effect of low oxygen on these lung tumor cell lines was evaluated. We found that hypoxia dramatically elevates NOTCH signaling (especially NOTCH-1) in lung tumor cell lines and concomitantly sensitizes them to inhibition via small-molecule γ-secretase inhibitors or NOTCH-1 RNA interference. γ-Secretase inhibitor–induced apoptosis of lung tumor cells grown under hypoxic conditions could be rescued by reintroduction of active NOTCH-1. Our data strengthen the role of NOTCH in lung cancer and as a therapeutic target for the treatment of lung and other hypoxic tumor types. [Cancer Res 2007;67(17):7954–9]
Clostridium perfringens Enterotoxin as a Novel-Targeted Therapeutic for Brain Metastasis
Authors: Kominsky Scott L. , Tyler Betty , Sosnowski Jeffrey , Brady Kelly , Doucet Michele , Nell Delissa , Smedley James G. , McClane Bruce , Brem Henry , Sukumar Saraswati
Published: September 2007

Brain metastasis is the most commonly occurring intracranial tumor whose incidence seems to be increasing. With standard therapy, the average survival time of patients is ∼8 months, and treatment often leads to neurologic dysfunction in long-term survivors, emphasizing the need for novel therapeutics. Clostridium perfringens enterotoxin (CPE) has recently been shown to rapidly and specifically destroy cancer cells expressing CPE receptors claudin-3 and claudin-4. Unfortunately, the utility of CPE is precluded by systemic toxicity because its receptors are expressed in numerous organs. Here, we provide the first preclinical evidence that CPE may be uniquely suited to the local treatment of brain metastasis. By immunohistochemical analysis, claudin-3 and claudin-4 were expressed frequently in metastases from breast (15 of 18), lung (15 of 20), and colon (12 of 14) carcinoma, and infrequently in metastases from renal cell carcinoma (2 of 16) and melanoma (2 of 16). In contrast, expression of claudin-3 and claudin-4 was absent in adjacent normal brain tissue. Further examination of the central nervous system (CNS) revealed low or undetectable levels of claudin-3 and claudin-4 in all regions tested by Western and immunohistochemical analysis. Treatment of breast cancer cell lines (MCF-7, MDA-MB-468, NT2.5-luc) and normal human astrocytes with CPE in vitro resulted in rapid and dose-dependent cytolysis exclusively in breast cancer cells, correlating with claudin-3 and claudin-4 expression. Moreover, intracranial CPE treatment significantly inhibited tumor growth and increased survival in two murine models of breast cancer brain metastasis, without any apparent local or systemic toxicity. These data suggest that CPE therapy may have efficacy against a wide variety of brain metastases without CNS toxicity. [Cancer Res 2007;67(17):7977–82]
YM155, a Novel Small-Molecule Survivin Suppressant, Induces Regression of Established Human Hormone-Refractory Prostate Tumor Xenografts
Authors: Nakahara Takahito , Takeuchi Masahiro , Kinoyama Isao , Minematsu Tsuyoshi , Shirasuna Kenna , Matsuhisa Akira , Kita Aya , Tominaga Fumiko , Yamanaka Kentaro , Kudoh Masafumi , Sasamata Masao
Published: September 2007

Various accumulating evidence suggests that survivin, a member of the inhibitor of apoptosis (IAP) family, plays an important role in drug resistance and cancer cell survival in many types of cancer, including hormone-refractory prostate cancer (HRPC). Here, we characterized YM155, a novel small-molecule survivin suppressant, using a survivin gene promoter activity assay. YM155 suppressed expression of survivin and induced apoptosis in PC-3 and PPC-1 human HRPC cell lines at 10 nmol/L. In contrast, YM155 up to 100 nmol/L showed little effect on expression levels of other IAP- or Bcl-2–related proteins. In a s.c. xenografted PC-3 tumor model in mice, 3-day continuous infusions of YM155 at 3 to 10 mg/kg induced massive tumor regression accompanied by suppression of intratumoral survivin. YM155 also completely inhibited the growth of orthotopically xenografted PC-3 tumors. No significant decreases in body weight were observed in mice treated with YM155 during the experimental period. Pharmacokinetic analyses indicated that YM155 is highly distributed to tumors and at concentrations ∼20-fold higher than those in plasma. Our findings represent the first attempt to show tumor regression and suppression of survivin in p53-deficient human HRPC cells by a single small molecular compound treatment. Further extensive investigation of YM155 in many types of cancer, including HRPC, seems to be worthwhile to develop this novel therapeutic approach. [Cancer Res 2007;67(17):8014–21]
Expression of Interleukin-13 Receptor α2 in Glioblastoma Multiforme: Implications for Targeted Therapies
Authors: Jarboe John S. , Johnson Kory R. , Choi Yong , Lonser Russell R. , Park John K.
Published: September 2007

Glioblastoma multiforme is the most common primary malignant brain tumor and despite treatment with surgery, radiation, and chemotherapy, the median survival of patients with glioblastoma multiforme is ∼1 year. Glioblastoma multiforme explants and cell lines have been reported to overexpress the interleukin-13 receptor α2 subunit (IL13Rα2) relative to nonneoplastic brain. Based on this finding, a recombinant cytotoxin composed of IL13 ligand and a truncated form of Pseudomonas aeruginosa exotoxin A (IL13-PE38QQR) was developed for the targeted treatment of glioblastoma multiforme tumors. In a recently completed phase III clinical trial, however, IL13-PE38QQR was found to be no more effective than an existing therapy in prolonging survival. To determine possible explanations for this result, we analyzed the relative expression levels of IL13Rα2 in glioblastoma multiforme and nonneoplastic brain specimens using publicly available oligonucleotide microarray databases, quantitative real-time reverse transcription PCR, and immunohistochemical staining. Increased expression of the IL13Rα2 gene relative to nonneoplastic brain was observed in 36 of 81 (44%) and 8 of 17 (47%) tumor specimens by microarray and quantitative real-time reverse transcription PCR analyses, respectively. Immunohistochemical staining of tumor specimens showed highly variable expression of IL13Rα2 protein both within and across specimens. These data indicate that prescreening of subjects may be of benefit in future trials of IL13Rα2 targeting therapies. [Cancer Res 2007;67(17):7983–6]