bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genistein Represses Telomerase Activity via Both Transcriptional and Posttranslational Mechanisms in Human Prostate Cancer Cells
Authors: Jagadeesh Shankar , Kyo Satoru , Banerjee Partha P. 
Published: February 2006

Abstract
Genistein, the most abundant isoflavone present in soybean has antiproliferative effects on a variety of cancer cells, including prostate cancer. However, the molecular mechanism of antiproliferative effects of genistein is not entirely understood. Because the activation of telomerase is crucial for cells to gain immortality and proliferation ability, we examined the role of genistein in the regulation of telomerase activity in prostate cancer cells. Here, we show that genistein-induced inhibition in cell proliferation is associated with a reduction in telomerase activity. Using reverse transcriptase-PCR and hTERT promoter activity assays, we showed that genistein decreased hTERT expression and transcriptional activity dose-dependently. Using various deleted hTERT promoter constructs, we defined that the hTERT core promoter is enough to observe the genistein-induced repression of hTERT transcriptional activity. Because c-Myc is involved in transcriptional regulation of hTERT, c-Myc expression was examined. A dose-dependent decrease in c-Myc message and proteins was observed with genistein treatment. These results indicate that genistein represses hTERT transcriptional activity via the down-regulation of c-Myc expression. However, genistein-induced repression of hTERT transcriptional activity was not blocked by the mutation of c-Myc at the hTERT promoter, suggesting that additional factors are involved in genistein-dependent repression of telomerase activity. Interestingly, we observed that genistein down-regulates the activation of Akt thereby phosphorylation of hTERT and inhibits its translocation to the nucleus. These results show for the first time that genistein represses telomerase activity in prostate cancer cells not only by repressing hTERT transcriptional activity via c-Myc but also by posttranslational modification of hTERT via Akt. (Cancer Res 2006; 66(4): 2107-15)
Relationship of Gene Expression and Chromosomal Abnormalities in Colorectal Cancer
Authors: Tsafrir Dafna , Bacolod Manny , Selvanayagam Zachariah , Tsafrir Ilan , Shia Jinru , Zeng Zhaoshi , Liu Hao , Krier Curtis , Stengel Robert F. , Barany Francis , Gerald William L. , Paty Philip B. , Domany Eytan , Notterman Daniel A. 
Published: February 2006

Abstract
Several studies have verified the existence of multiple chromosomal abnormalities in colon cancer. However, the relationships between DNA copy number and gene expression have not been adequately explored nor globally monitored during the progression of the disease. In this work, three types of array-generated data (expression, single nucleotide polymorphism, and comparative genomic hybridization) were collected from a large set of colon cancer patients at various stages of the disease. Probes were annotated to specific chromosomal locations and coordinated alterations in DNA copy number and transcription levels were revealed at specific positions. We show that across many large regions of the genome, changes in expression level are correlated with alterations in DNA content. Often, large chromosomal segments, containing multiple genes, are transcriptionally affected in a coordinated way, and we show that the underlying mechanism is a corresponding change in DNA content. This implies that whereas specific chromosomal abnormalities may arise stochastically, the associated changes in expression of some or all of the affected genes are responsible for selecting cells bearing these abnormalities for clonal expansion. Indeed, particular chromosomal regions are frequently gained and overexpressed (e.g., 7p, 8q, 13q, and 20q) or lost and underexpressed (e.g., 1p, 4, 5q, 8p, 14q, 15q, and 18) in primary colon tumors, making it likely that these changes favor tumorigenicity. Furthermore, we show that these aberrations are absent in normal colon mucosa, appear in benign adenomas (albeit only in a small fraction of the samples), become more frequent as disease advances, and are found in the majority of metastatic samples. (Cancer Res 2006; 66(4): 2129-37)
Increased Frequency of Aberrations in the p53/MDM2/p14ARF Pathway in Neuroblastoma Cell Lines Established at Relapse
Authors: Carr Jane , Bell Emma , Pearson Andrew D.J. , Kees Ursula R. , Beris Helen , Lunec John , Tweddle Deborah A. 
Published: February 2006

Abstract
p53 mutations have been reported in cell lines derived from relapsed neuroblastoma tumors. We hypothesize that functional inactivation of p53 by mutation or other mechanisms is common in relapsed neuroblastoma and can contribute to chemoresistance. Our aim was to determine the frequency of p53 mutations, p14ARF methylation, or deletion and MDM2 amplification in 23 neuroblastoma cell lines (6 derived at diagnosis and 17 derived at relapse). One cell line was p53 mutant (BE2c) and two cell lines were deleted for p14ARF (LAN-6 and SHEP). Two cell lines were methylated for p14ARF (GIMEN and PER-108), one of which had low levels of p14ARF mRNA expression which increased following demethylation with 5-aza-2/deoxycytidine treatment (GIMEN), and four cell lines were confirmed to be MDM2-amplified. All these cell lines were derived from neuroblastomas at relapse. Inactivation of the p53 pathway was observed in 9 out of 17 neuroblastoma cell lines (53%) established at relapse and in none of the cell lines established from pretreatment tumors. If these data are confirmed in neuroblastoma tumors, this suggests that p53-independent therapy and reactivation of inactive p53 approaches would be useful in the management of relapsed neuroblastoma. (Cancer Res 2006; 66(4): 2138-45)
Glioma Virotherapy: Effects of Innate Immune Suppression and Increased Viral Replication Capacity
Authors: Friedman Avner , Tian Jianjun Paul , Fulci Giulia , Chiocca E. Antonio , Wang Jin 
Published: February 2006

Abstract
Oncolytic viruses are genetically altered replication-competent viruses that infect, and reproduce in, cancer cells but do not harm normal cells. On lysis of the infected cells, the newly formed viruses burst out and infect other tumor cells. Experiments with injecting mutant herpes simplex virus 1 (hrR3) into glioma implanted in brains of rats show lack of efficacy in eradicating the cancer. This failure is attributed to interference by the immune system. Initial pretreatment with immunosuppressive agent cyclophosphamide reduces the percentage of immune cells. We introduce a mathematical model and use it to determine how different protocols of cyclophosphamide treatment and how increased burst size of the mutated virus will affect the growth of the cancer. One of our conclusions is that the diameter of the cancer will decrease from 4 mm to eventually 1 mm if the burst size of the virus is triple that which is currently available. The effect of repeated cyclophosphamide treatment is to maintain a low density of uninfected cells in the tumor, thus reducing the probability of migration of tumor cells to other locations in the brain. (Cancer Res 2006; 66(4): 2314-9)
Lymphocyte Activation Antigen CD70 Expressed by Renal Cell Carcinoma Is a Potential Therapeutic Target for Anti-CD70 Antibody-Drug Conjugates
Authors: Law Che-Leung , Gordon Kristine A. , Toki Brian E. , Yamane Andrew K. , Hering Michelle A. , Cerveny Charles G. , Petroziello Joseph M. , Ryan Maureen C. , Smith Leia , Simon Ronald , Sauter Guido , Oflazoglu Ezogelin , Doronina Svetlana O. , Meyer Damon L. , Francisco Joseph A. , Carter Paul , Senter Peter D. , Copland John A. , Wood Christopher G. , Wahl Alan F. 
Published: February 2006

AbstractMetastatic renal cell carcinoma (RCC) is an aggressive disease refractory to most existing therapeutic modalities. Identifying new markers for disease progression and drug targets for RCC will benefit this unmet medical need. We report a subset of clear cell and papillary cell RCC aberrantly expressing the lymphocyte activation marker CD70, a member of the tumor necrosis factor superfamily. Importantly, CD70 expression was found to be maintained at the metastatic sites of RCC. Anti-CD70 antibody-drug conjugates (ADC) consisting of auristatin phenylalanine phenylenediamine (AFP) or monomethyl auristatin phenylalanine (MMAF), two novel derivatives of the anti-tubulin agent auristatin, mediated potent antigen-dependent cytotoxicity in CD70-expressing RCC cells. Cytotoxic activity of these anti-CD70 ADCs was associated with their internalization and subcellular trafficking through the endosomal-lysosomal pathway, disruption of cellular microtubule network, and G2-M phase cell cycle arrest. The efficiency of drug delivery using anti-CD70 as vehicle was illustrated by the much enhanced cytotoxicity of antibody-conjugated MMAF compared with free MMAF. Hence, ADCs targeted to CD70 can selectively recognize RCC, internalize, and reach the appropriate subcellular compartment(s) for drug release and tumor cell killing. In vitro cytotoxicity of these ADCs was confirmed in xenograft models using RCC cell lines. Our findings provide evidence that CD70 is an attractive target for antibody-based therapeutics against metastatic RCC and suggest that anti-CD70 ADCs can provide a new treatment approach for advanced RCC patients who currently have no chemotherapeutic options. (Cancer Res 2006; 66(4): 2328-37)
The Forkhead Box m1 Transcription Factor Stimulates the Proliferation of Tumor Cells during Development of Lung Cancer
Authors: Kim Il-Man , Ackerson Timothy , Ramakrishna Sneha , Tretiakova Maria , Wang I-Ching , Kalin Tanya V. , Major Michael L. , Gusarova Galina A. , Yoder Helena M. , Costa Robert H. , Kalinichenko Vladimir V. 
Published: February 2006

Abstract
The proliferation-specific Forkhead Box m1 (Foxm1 or Foxm1b) transcription factor (previously called HFH-11B, Trident, Win, or MPP2) regulates expression of cell cycle genes essential for progression into DNA replication and mitosis. Expression of Foxm1 is found in a variety of distinct human cancers including hepatocellular carcinomas, intrahepatic cholangiocarcinomas, basal cell carcinomas, ductal breast carcinomas, and anaplastic astrocytomas and glioblastomas. In this study, we show that human Foxm1 protein is abundantly expressed in highly proliferative human non–small cell lung cancers (NSCLC) as well as in mouse lung tumors induced by urethane. To determine the role of Foxm1 during the development of mouse lung tumors, we used IFN-inducible Mx-Cre recombinase transgene to delete mouse Foxm1 fl/fl–targeted allele before inducing lung tumors with urethane. We show that Mx-Cre Foxm1−/− mice exhibit diminished proliferation of lung tumor cells causing a significant reduction in number and size of lung adenomas. Transient transfection experiments with A549 lung adenocarcinoma cells show that depletion of Foxm1 levels by short interfering RNA caused diminished DNA replication and mitosis and reduced anchorage-independent growth of cell colonies on soft agar. Foxm1-depleted A549 cells exhibit reduced expression of cell cycle–promoting cyclin A2 and cyclin B1 genes. These data show that Foxm1 stimulates the proliferation of tumor cells during progression of NSCLC. (Cancer Res 2006; 66(4): 2153-61)
Down-regulation of Insulin Receptor by Antibodies against the Type I Insulin-Like Growth Factor Receptor: Implications for Anti–Insulin-Like Growth Factor Therapy in Breast Cancer
Authors: Sachdev Deepali , Singh Rajeeva , Fujita-Yamaguchi Yoko , Yee Douglas 
Published: February 2006

AbstractInsulin-like growth factor-I (IGF-I), IGF-II, and insulin have all been implicated in regulating several aspects of the malignant phenotype via the type I IGF receptor (IGF1R) and insulin receptor (IR). We have previously shown that a chimeric single-chain antibody against IGF1R (scFv-Fc) and a murine antibody EM164 down-regulate IGF1R, making breast cancer cells unresponsive to IGF-I. To determine if IR signaling is affected, we examined regulation of IR in MCF-7 cells after exposure to these antibodies. Surprisingly, both scFv-Fc and EM164 resulted in decreased levels of IR in vitro and in vivo despite their lack of reactivity against IR. Twenty-four-hour pretreatment with EM164 also inhibited insulin-mediated phosphorylation of IR and insulin-stimulated proliferation of MCF-7 cells. Neither scFv-Fc nor EM164 caused down-regulation of IR in cells that express very low levels of IGF1R or no IGF1R. Expression of IGF1R was required for IR down-regulation, which was specific as neither antibody caused down-regulation of β1 integrin or epidermal growth factor receptor. Reagents that disrupt lipid rafts inhibited IR down-regulation by the antibodies, suggesting that IR in close physical proximity to IGF1R in lipid rafts was being endocytosed. Our data show that down-regulation of IR by monoclonal antibodies against IGF1R requires the coexpression of IGF1R and may be due to endocytosis of hybrid IR/IGF1R or holo-IR. Thus, antibodies against IGF1R provide inhibition of both IGF and insulin signaling in cancer cells. (Cancer Res 2006; 66(4): 2391-402)
A Gene Expression Signature that Can Predict Green Tea Exposure and Chemopreventive Efficacy of Lung Cancer in Mice
Authors: Lu Yan , Yao Ruisheng , Yan Ying , Wang Yian , Hara Yukihiko , Lubet Ronald A. , You Ming 
Published: February 2006

Abstract
Green tea has been shown to be a potent chemopreventive agent against lung tumorigenesis in animal models. Previously, we found that treatment of A/J mice with either green tea (0.6% in water) or a defined green tea catechin extract (polyphenon E; 2.0 g/kg in diet) inhibited lung tumor tumorigenesis. Here, we described expression profiling of lung tissues derived from these studies to determine the gene expression signature that can predict the exposure and efficacy of green tea in mice. We first profiled global gene expressions in normal lungs versus lung tumors to determine genes which might be associated with the tumorigenic process (TUM genes). Gene expression in control tumors and green tea–treated tumors (either green tea or polyphenon E) were compared to determine those TUM genes whose expression levels in green tea–treated tumors returned to levels seen in normal lungs. We established a 17-gene expression profile specific for exposure to effective doses of either green tea or polyphenon E. This gene expression signature was altered both in normal lungs and lung adenomas when mice were exposed to green tea or polyphenon E. These experiments identified patterns of gene expressions that both offer clues for green tea's potential mechanisms of action and provide a molecular signature specific for green tea exposure. (Cancer Res 2006; 66(4): 1956-63)
Xanthine Oxidase–Dependent Regulation of Hypoxia-Inducible Factor in Cancer Cells
Authors: Griguer Corinne E. , Oliva Claudia R. , Kelley Eric E. , Giles Gregory I. , Lancaster Jack R. , Gillespie G. Yancey 
Published: February 2006

AbstractDuring chemical hypoxia induced by cobalt chloride (CoCl2), hypoxia-inducible factor 1α (HIF1-α) mediates the induction of a variety of genes including erythropoietin and vascular endothelial growth factor. We used glioma cells with oxidative phosphorylation–dependent (D54-MG) and glycolytic-dependent (U251-MG) phenotypes to monitor HIF1-α regulation in association with redox responsiveness to CoCl2 treatment. We showed that CoCl2 increased xanthine oxidase (XO)–derived reactive oxygen species (ROS), which causes accumulation of HIF1-α protein in U251-MG cells. Under these conditions, blockade of XO activity by pharmacologic (N-acetyl-l-cysteine or allopurinol) or molecular (by small interfering RNA) approaches significantly attenuated HIF1-α expression. Exogenous H2O2 stabilizes HIF1-α protein. XO was present in these cells and was the primary source of free radicals. We also showed higher XO activity in cells exposed to CoCl2 compared with cells grown in normoxia. From the experiments shown here, we concluded that ROS were indeed generated in D54-MG cells exposed to CoCl2 but it was unlikely that ROS participated in the hypoxic signal transduction pathways in this cell type. Possibly, cell type–dependent and stimulus-dependent factors may control ROS dependency or redox sensitivity of HIF1-α and thus HIF1-α activation either directly or by induction of specific signaling cascades. Our findings reveal that XO-derived ROS is a novel and critical component of HIF1-α regulation in U251-MG cells, pointing toward a more general role of this transcription factor in tumor progression. (Cancer Res 2006; 66(4): 2257-63)
Tumor Endothelial Cells Express Epidermal Growth Factor Receptor (EGFR) but not ErbB3 and Are Responsive to EGF and to EGFR Kinase Inhibitors
Authors: Amin Dhara N. , Hida Kyoko , Bielenberg Diane R. , Klagsbrun Michael 
Published: February 2006

Abstract
Epidermal growth factor (EGF) receptor family members are expressed by tumor cells and contribute to tumor progression. The expression and activity of EGF receptors in endothelial cells are less well characterized. Analysis of tumor-derived endothelial cells showed that they express EGFR, ErbB2, and ErbB4, whereas their normal counterparts express ErbB2, ErbB3, and ErbB4. The gain in expression of EGFR and the loss of ErbB3 expression in tumor vasculature was also observed in vivo. As a consequence of their expressing EGFR, tumor endothelial cells responded to EGF and other EGF family members by activating both EGFR and ErbB2, by activating the downstream mitogen-activated protein kinase pathway, and by enhanced proliferation. On the other hand, normal endothelial cells did not respond to EGF but instead were responsive to neuregulin (NRG), a ligand for ErbB3 and ErbB4. NRG activated ErbB3 in normal endothelial cells and inhibited growth of these cells. In contrast, tumor endothelial cells, which do not express ErbB3, were not growth inhibited by NRG. Furthermore, due to their expression of EGFR, tumor endothelial cells, unlike normal endothelial cells, are direct targets for EGFR kinase inhibitors. These low-molecular-weight compounds block EGF-induced EGFR activation and proliferation of tumor endothelial cells. These results suggest that a gain of EGF-induced endothelial cell proliferation, and loss of NRG-induced growth inhibition in tumor endothelial cells constitutes a switch that promotes tumor angiogenesis. In addition, these results suggest that EGFR kinase inhibitors may be effective for antiangiogenesis therapy by specifically targeting the tumor, but not the normal, vasculature. (Cancer Res 2006; 66(4): 2173-80)
Endocytic Recycling Compartments Altered in Cisplatin-Resistant Cancer Cells
Authors: Liang Xing-Jie , Mukherjee Sushmita , Shen Ding-Wu , Maxfield Frederick R. , Gottesman Michael M. 
Published: February 2006

Abstract
The clinical utility of cisplatin to treat human malignancies is often limited by the development of drug resistance. We have previously shown that cisplatin-resistant human KB adenocarcinoma cells that are cross-resistant to methotrexate and heavy metals have altered endocytic recycling. In this work, we tracked lipids in the endocytic recycling compartment (ERC) and found that the distribution of the ERC is altered in KB-CP.5 cells compared with parental KB-3-1 cells. A tightly clustered ERC is located near the nucleus in parental KB-3-1 cells but it appears loosely arranged and widely dispersed throughout the cytoplasm in KB-CP.5 cells. The altered distribution of the ERC in KB-CP.5 cells is related to the amount and distribution of stable detyrosinated microtubules (Glu-α-tubulin), as previously shown in Chinese hamster ovary B104-5 cells that carry a temperature-sensitive Glu-α-tubulin allele. In addition, B104-5 cells with a dispersed ERC under nonpermissive conditions were more resistant to cisplatin compared with B104-5 cells with a clustered ERC under permissive conditions. We conclude that resistance to cisplatin might be due, in part, to reduced uptake of cisplatin resulting from an endocytic defect reflecting defective formation of the ERC, possibly related to a shift in the relative amounts and distributions of stable microtubules. (Cancer Res 2006; 66(4): 2346-53)
Molecular Target-Based Therapy of Pancreatic Cancer
Authors: Lebedeva Irina V. , Sarkar Devanand , Su Zao-Zhong , Gopalkrishnan Rahul V. , Athar Mohammad , Randolph Aaron , Valerie Kristoffer , Dent Paul , Fisher Paul B. 
Published: February 2006

Abstract
Pancreatic cancer is genetically complex, and without effective therapy. Mutations in the Kirsten-ras (K-ras) oncogene occur early and frequently (∼90%) during pancreatic cancer development and progression. In this context, K-ras represents a potential molecular target for the therapy of this highly aggressive cancer. We now show that a bipartite adenovirus expressing a novel cancer-specific apoptosis-inducing cytokine gene, mda-7/interleukin-24 (IL-24), and a K-ras AS gene, but not either gene alone, promotes growth suppression, induction of apoptosis, and suppression of tumor development mediated by K-ras mutant pancreatic cancer cells. Equally, the combination of an adenovirus expressing mda-7/IL-24 and pharmacologic and genetic agents simultaneously blocking K-ras or downstream extracellular regulated kinase 1/2 signaling also promotes similar inhibitory effects on the growth and survival of K-ras mutant pancreatic carcinoma cells. This activity correlates with the reversal of a translational block in mda-7/IL-24 mRNA in pancreatic cancer cells that limits message association with polysomes, thereby impeding translation into protein. Our study provides support for a “dual molecular targeted therapy” involving oncogene inhibition and selective cancer apoptosis-inducing gene expression with potential for effectively treating an invariably fatal cancer. (Cancer Res 2006; 66(4): 2403-13)
Regression of Melanoma in a Murine Model by RLIP76 Depletion
Authors: Singhal Sharad S. , Awasthi Yogesh C. , Awasthi Sanjay 
Published: February 2006

AbstractRLIP76/RALBP1 is a stress-responsive membrane protein implicated in the regulation of multiple cellular signaling pathways. It represents the predominant glutathione-conjugate transporter in cells, and our previous studies have shown that its inhibition by antibodies or depletion by short interfering RNA (siRNA) causes apoptosis in a number of cancer cell types. The present studies were done to explore the potential clinical applicability of our previous observations by comparing the relative expression of RLIP76 in cancer versus normal cell lines and to determine whether depletion of RLIP76 activity can exert cancer-specific apoptosis. RLIP76 expression was found to be significantly greater in malignant cells compared to nonmalignant cells. Inhibition of RLIP76, using antibodies towards a cell surface epitope, or depletion of RLIP76 using either siRNA or antisense phosphorothioate oligonucleotides preferentially caused apoptosis in malignant cells. More importantly, in vivo studies showed that administration of RLIP76 antibodies, siRNA, or antisense oligonucleotides to mice bearing syngeneic B16 mouse melanoma cells caused complete tumor regression within 10 days. These findings strongly suggest that RLIP76 depletion by genetic approaches or inhibition by antibodies may be a clinically viable antineoplastic therapy, particularly for melanoma. (Cancer Res 2006; 66(4): 2354-60)