bluuebunny/crossref_metadata_2025_split huggingface dataset:
Homozygous Deletions and Chromosome Amplifications in Human Lung Carcinomas Revealed by Single Nucleotide Polymorphism Array Analysis
Authors: Zhao Xiaojun , Weir Barbara A. , LaFramboise Thomas , Lin Ming , Beroukhim Rameen , Garraway Levi , Beheshti Javad , Lee Jeffrey C. , Naoki Katsuhiko , Richards William G. , Sugarbaker David , Chen Fei , Rubin Mark A. , Jänne Pasi A. , Girard Luc , Minna John , Christiani David , Li Cheng , Sellers William R. , Meyerson Matthew 
Published: September 2005

AbstractGenome-wide copy number changes were analyzed in 70 primary human lung carcinoma specimens and 31 cell lines derived from human lung carcinomas, with high-density arrays representing ∼115,000 single nucleotide polymorphism loci. In addition to previously characterized loci, two regions of homozygous deletion were found, one near the PTPRD locus on chromosome segment 9p23 in four samples representing both small cell lung carcinoma (SCLC) and non–small cell lung carcinoma (NSCLC) and the second on chromosome segment 3q25 in one sample each of NSCLC and SCLC. High-level amplifications were identified within chromosome segment 8q12-13 in two SCLC specimens, 12p11 in two NSCLC specimens and 22q11 in four NSCLC specimens. Systematic copy number analysis of tyrosine kinase genes identified high-level amplification of EGFR in three NSCLC specimens, FGFR1 in two specimens and ERBB2 and MET in one specimen each. EGFR amplification was shown to be independent of kinase domain mutational status.
Shared Epigenetic Mechanisms in Human and Mouse Gliomas Inactivate Expression of the Growth SuppressorSLC5A8
Authors: Hong Chibo , Maunakea Alika , Jun Peter , Bollen Andrew W. , Hodgson J. Graeme , Goldenberg David D. , Weiss William A. , Costello Joseph F. 
Published: September 2005

AbstractTumors arise in part from the deleterious effects of genetic and epigenetic mechanisms on gene expression. In several mouse models of human tumors, the tumorigenic phenotype is reversible, suggesting that epigenetic mechanisms also contribute significantly to tumorigenesis in mice. It is not known whether these are the same epigenetic mechanisms in human and mouse tumors or whether they affect homologous genes. Using an integrated approach for genome-wide methylation and copy number analyses, we identified SLC5A8 on chromosome 12q23.1 that was affected frequently by aberrant methylation in human astrocytomas and oligodendrogliomas. SLC5A8 encodes a sodium monocarboxylate cotransporter that was highly expressed in normal brain but was significant down-regulated in primary gliomas. Bisulfite sequencing analysis showed that the CpG island was unmethylated in normal brain but frequently localized methylated in brain tumors, consistent with the tumor-specific loss of gene expression. In glioma cell lines, SLC5A8 expression was also suppressed but could be reactivated with a methylation inhibitor. Expression of exogenous SLC5A8 in LN229 and LN443 glioma cells inhibited colony formation, suggesting that it may function as a growth suppressor in normal brain cells. Remarkably, 9 of 10 murine oligodendroglial tumors (from p53+/− or ink4a/arf+/− animals transgenic for S100β-v-erbB) showed a similar tumor-specific down-regulation of mSLC5A8, the highly conserved mouse homologue. Taken together, these data suggest that SLC5A8 functions as a growth suppressor gene in vitro and that it is silenced frequently by epigenetic mechanisms in primary gliomas. The shared epigenetic inactivation of mSLC5A8 in mouse gliomas indicates an additional degree of commonality in the origin and/or pathway to tumorigenesis between primary human tumors and these mouse models of gliomas.
Association of DNA Methylation of Phosphoserine Aminotransferase with Response to Endocrine Therapy in Patients with Recurrent Breast Cancer
Authors: Martens John W.M. , Nimmrich Inko , Koenig Thomas , Look Maxime P. , Harbeck Nadia , Model Fabian , Kluth Antje , Bolt-de Vries Joan , Sieuwerts Anieta M. , Portengen Henk , Meijer-Van Gelder Marion E. , Piepenbrock Christian , Olek Alexander , Höfler Heinz , Kiechle Marion , Klijn Jan G.M. , Schmitt Manfred , Maier Sabine , Foekens John A. 
Published: September 2005

Abstract
To understand the biological basis of resistance to endocrine therapy is of utmost importance in patients with steroid hormone receptor–positive breast cancer. Not only will this allow us prediction of therapy success, it may also lead to novel therapies for patients resistant to current endocrine therapy. DNA methylation in the promoter regions of genes is a prominent epigenetic gene silencing mechanism that contributes to breast cancer biology. In the current study, we investigated whether promoter DNA methylation could be associated with resistance to endocrine therapy in patients with recurrent breast cancer. Using a microarray-based technology, the promoter DNA methylation status of 117 candidate genes was studied in a cohort of 200 steroid hormone receptor–positive tumors of patients who received the antiestrogen tamoxifen as first-line treatment for recurrent breast cancer. Of the genes analyzed, the promoter DNA methylation status of 10 genes was significantly associated with clinical outcome of tamoxifen therapy. The association of the promoter hypermethylation of the strongest marker, phosphoserine aminotransferase (PSAT1) with favorable clinical outcome was confirmed by an independent quantitative DNA methylation detection method. Furthermore, the extent of DNA methylation of PSAT1 was inversely associated with its expression at the mRNA level. Finally, also at the mRNA level, PSAT1 was a predictor of tamoxifen therapy response. Concluding, our work indicates that promoter hypermethylation and mRNA expression of PSAT1 are indicators of response to tamoxifen-based endocrine therapy in steroid hormone receptor–positive patients with recurrent breast cancer.
K-ras Codon-Specific Mutations Produce Distinctive Metabolic Phenotypes in Human Fibroblasts
Authors: Vizan Pedro , Boros Laszlo G. , Figueras Agnes , Capella Gabriel , Mangues Ramon , Bassilian Sara , Lim Shu , Lee Wai-Nang P. , Cascante Marta 
Published: September 2005

Abstract
Among K-ras mutations, codon 12 mutations have been identified as those conferring a more aggressive phenotype. This aggressiveness is primarily associated with slow proliferation but greatly increased resistance to apoptosis. Using transfected NIH3T3 fibroblasts with a mutated K-ras minigene either at codon 12 (K12) or at codon 13 (K13), and taking advantage of [1,2-13C2]glucose tracer labeling, we show that codon 12 mutant K-ras (K12)-transformed cells exhibit greatly increased glycolysis with only a slight increase in activity along pathways that produce nucleic acid and lipid synthesis precursors in the oxidative branch of the pentose phosphate pathway and via pyruvate dehydrogenase flux. K13 mutants display a modest increase in anaerobic glycolysis associated with a large increase in oxidative pentose phosphate pathway activity and pyruvate dehydrogenase flux. The distinctive differences in metabolic profiles of K12 and K13 codon mutated cells indicate that a strong correlation exists between the flow of glucose carbons towards either increased anaerobic glycolysis, and resistance to apoptosis (K12), or increased macromolecule synthesis, rapid proliferation, and increased sensitivity to apoptosis.
Characterization of the Mismatch Repair Defect in the Human Lymphoblastoid MT1 Cells
Authors: Szadkowski Marta , Iaccarino Ingram , Heinimann Karl , Marra Giancarlo , Jiricny Josef 
Published: September 2005

Abstract
Mutations in mismatch repair (MMR) genes predispose to hereditary nonpolyposis colon cancer. Those leading to truncated proteins bring about a MMR defect, but phenotypes of missense mutations are harder to predict especially if they do not affect conserved residues. Several systems capable of predicting the phenotypes of MMR missense mutations were described. We deployed one of these to study the MMR defect in MT1 cells, which carry mutations in both alleles of the hMSH6 gene. In one, an A→T transversion brings about an Asp(1213)Val amino acid change in the highly conserved ATP binding site, whereas the other carries a G→A transition, which brings about a Val(1260)Ile change at a nonconserved site. The hMSH2/hMSH6 (hMutSα) heterodimers carrying these mutations were expressed in the baculovirus system and tested in in vitro MMR assays. As anticipated, the Asp(1213)Val mutation inactivated MMR by disabling the variant hMutSα from translocating along the DNA. In contrast, the recombinant Val(1260)Ile variant displayed wild-type activity. Interestingly, partial proteolytic analysis showed that this heterodimer was absent from MT1 extracts, although both hMSH6 alleles in MT1 cells could be shown to be transcribed with an efficiency similar to each other and to that seen in control cells. The MMR defect in MT1 cells is thus the compound result of one mutation that inactivates the ATPase function of hMutSα and a second mutation that apparently destabilizes the Val(1260)Ile hMSH6 protein in human cells in vivo.
SV40-Dependent AKT Activity Drives Mesothelial Cell Transformation after Asbestos Exposure
Authors: Cacciotti Paola , Barbone Dario , Porta Camillo , Altomare Deborah A. , Testa Joseph R. , Mutti Luciano , Gaudino Giovanni 
Published: September 2005

Abstract
Human malignant mesothelioma is an aggressive cancer generally associated with exposure to asbestos, although SV40 virus has been involved as a possible cofactor by a number of studies. Asbestos fibers induce cytotoxicity in human mesothelial cells (HMC), although cell survival activated by key signaling pathways may promote transformation. We and others previously reported that SV40 large T antigen induces autocrine loops in HMC and malignant mesothelioma cells, leading to activation of growth factor receptors. Now we show that SV40 induces cell survival via Akt activation in malignant mesothelioma and HMC cells exposed to asbestos. Consequently, prolonged exposure to asbestos fibers progressively induces transformation of SV40-positive HMC. As a model of SV40/asbestos cocarcinogenesis, we propose that malignant mesothelioma originates from a subpopulation of transformed stem cells and that Akt signaling is a novel therapeutic target to overcome malignant mesothelioma resistance to conventional therapies.
A Ras Homologue Member I Directly Inhibits Signal Transducers and Activators of Transcription 3 Translocation and Activity in Human Breast and Ovarian Cancer Cells
Authors: Nishimoto Arata , Yu Yinhua , Lu Zhen , Mao Xiang , Ren Zhiyong , Watowich Stephanie S. , Mills Gordon B. , Liao Warren S-L. , Chen Xiaomin , Bast Robert C. , Luo Robert Z. 
Published: September 2005

Abstract
A Ras homologue member I (ARHI) is a novel imprinted tumor suppressor gene whose expression is frequently lost in breast and ovarian cancers. This small GTP-binding protein is a member of the Ras superfamily with significant homology to both Ras and Rap. Unlike the Ras oncogene, however, ARHI inhibits tumor cell growth. To elucidate the mechanisms by which ARHI inhibits cancer growth, we screened a human breast epithelial cell cDNA library using a yeast two-hybrid system for ARHI-interacting proteins. ARHI was found to interact with signal transducers and activators of transcription (STAT) 3, a latent transcription factor that transduces signals from the cell surface to the nucleus and activates gene transcription. STAT3 is frequently phosphorylated and activated in breast and ovarian cancers, where cytokines and growth factors up-regulate STAT3 and stimulate proliferation. The ARHI-STAT3 interaction was confirmed by coimmunoprecipitation in mammalian cells and shown to be specific for STAT3 but not STAT1 or STAT5a. When ARHI and STAT3 were coexpressed in SKOv3 cells, ARHI formed a complex with STAT3 in the cytoplasm and prevented interleukin-6–induced STAT3 accumulation in the nucleus. ARHI markedly reduced STAT3 binding to DNA and STAT3-dependent promoter activity while only moderately affecting STAT3 phosphorylation. Deletion of the NH2 terminus of ARHI significantly compromised its inhibitory activity, suggesting that this unique NH2-terminal extension contributes to ARHI's inhibition of STAT3-mediated transcriptional activity. Thus, the physical association between STAT3 and ARHI as well as the functional inhibition of STAT3 transcriptional activity by ARHI suggests a novel mechanism through which a putative tumor suppressor gene can inhibit STAT3 activity in breast and ovarian cancers.
Brain Tumor Oncolysis with Replication-Conditional Herpes Simplex Virus Type 1 Expressing the Prodrug-Activating Genes, CYP2B1 and Secreted Human Intestinal Carboxylesterase, in Combination with Cyclophosphamide and Irinotecan
Authors: Tyminski Edyta , LeRoy Stanley , Terada Kinya , Finkelstein Dianne M. , Hyatt Janice L. , Danks Mary K. , Potter Philip M. , Saeki Yoshinaga , Chiocca E. Antonio 
Published: September 2005

Abstract
The treatment of malignant glioma is currently ineffective. Oncolytic viruses are being explored as a means to selectively lyse tumor cells in the brain. We have engineered a mutant herpes simplex virus type 1 with deletions in the viral UL39 and γ134.5 genes and an insertion of the two prodrug activating genes, CYP2B1 and secreted human intestinal carboxylesterase. Each of these can convert the inactive prodrugs, cyclophosphamide and irinotecan (CPT-11), into their active metabolites, respectively. This new oncolytic virus (MGH2) displays increased antitumor efficacy against human glioma cells both in vitro and in vivo when combined with cyclophosphamide and CPT-11. Importantly, cyclophosphamide, CPT-11, or the combination of cyclophosphamide and CPT-11 does not significantly affect oncolytic virus replication. Therefore, MGH2 provides effective multimodal therapy for gliomas in preclinical models when combined with these chemotherapy agents.
Bisphosphonates and Cancer-Induced Bone Disease: Beyond Their Antiresorptive Activity
Authors: Clézardin Philippe , Ebetino Frank H. , Fournier Pierrick G.J. 
Published: September 2005

AbstractBisphosphonates are primarily known for their ability to inhibit osteoclast-mediated bone resorption. They are an indispensable part of therapy for patients with cancers that cause osteolysis. However, there is now a growing body of evidence from preclinical research showing that bisphosphonates also exhibit antitumor activity, both in vitro and in vivo. They can affect molecular mechanisms of tumor cell adhesion, invasion, and proliferation; reinforce the effects of cytotoxic agents in a synergistic manner; and exhibit antiangiogenic and immunomodulatory effects. These preclinical findings reveal exciting ways of optimizing bisphosphonate therapy in oncology to fully exploit their antitumor potential.
Malignant Transformation but not Normal Cell Growth Depends on Signal Transducer and Activator of Transcription 3
Authors: Schlessinger Karni , Levy David E. 
Published: September 2005

Abstract
Signal transducer and activator of transcription 3 (STAT3) has been indirectly implicated in numerous fundamental cellular processes, including proliferation, survival, and differentiation. We provide genetic evidence from studies of STAT3-null cells that STAT3 is dispensable for normal growth of mouse fibroblasts in culture. STAT3 contributed to the full induction of some (typified by c-fos) but not all (typified by c-myc) immediate early gene expression, but STAT3-independent processes were sufficient to support full cell growth and survival. However, STAT3 was required to manifest a transformed state following expression of v-src, and STAT3-null cells were impaired for anchorage-independent growth as colonies in soft agar and as tumors in mice. The data suggest that STAT3 mediates the maintenance of focal adhesion kinase activity in the absence of cell adhesion by suppressing the action of an inhibitory phosphatase.
Systemic Gene-Directed Enzyme Prodrug Therapy of Hepatocellular Carcinoma Using a Targeted Adenovirus Armed with Carboxypeptidase G2
Authors: Schepelmann Silke , Hallenbeck Paul , Ogilvie Lesley M. , Hedley Douglas , Friedlos Frank , Martin Janet , Scanlon Ian , Hay Carl , Hawkins Lynda K. , Marais Richard , Springer Caroline J. 
Published: September 2005

AbstractHepatocellular carcinoma is the fifth most common cancer worldwide, and there is no effective therapy for unresectable disease. We have developed a targeted systemic therapy for hepatocellular carcinoma. The gene for a foreign enzyme is selectively expressed in the tumor cells and a nontoxic prodrug is then given, which is activated to a potent cytotoxic drug by the tumor-localized enzyme. This approach is termed gene-directed enzyme prodrug therapy (GDEPT). Adenoviruses have been used to target cancer cells, have an intrinsic tropism for liver, and are efficient gene vectors. Oncolytic adenoviruses produce clinical benefits, particularly in combination with conventional anticancer agents and are well tolerated. We rationalized that such adenoviruses, if their expression were restricted to telomerase-positive cancer cells, would make excellent gene vectors for GDEPT therapy of hepatocellular carcinoma. Here we use an oncolytic adenovirus to deliver the prodrug-activating enzyme carboxypeptidase G2 (CPG2) to tumors in a single systemic administration. The adenovirus replicated and produced high levels of CPG2 in two different hepatocellular carcinoma xenografts (Hep3B and HepG2) but not other tissues. GDEPT enhanced the adenovirus-alone therapy to elicit tumor regressions in the hepatocellular carcinoma models. This is the first time that CPG2 has been targeted and expressed intracellularly to effect significant therapy, showing that the combined approach holds enormous potential as a tumor-selective therapy for the systemic treatment of hepatocellular carcinoma.
Enhancement of 5-Fluorouracil Sensitivity by an rTS Signaling Mimic in H630 Colon Cancer Cells
Authors: Dolnick Ree , Wu Qi , Angelino Norman J. , Stephanie Lawrence V. , Chow Kuan-Chih , Sufrin Janice R. , Dolnick Bruce J. 
Published: September 2005

Abstract
The rTSβ protein has been hypothesized to synthesize signaling molecules that can down-regulate thymidylate synthase. These molecules share biological and chemical properties with acyl-homoserine lactones (AHL), suggesting some AHLs might act as rTS signaling mimics and down-regulate thymidylate synthase. We have determined that the AHL, 3-oxododecanoyl homoserine lactone (3-oxo-C12-(l)-HSL) can down-regulate thymidylate synthase protein at 10 μmol/L and reduce H630 (human colorectal cancer) growth by 50% at 23 μmol/L (IC50) in cell culture. At its IC50 concentration, 3-oxo-C12-(l)-HSL reduces the apparent IC50 of 5-fluorouracil (5-FU) from 1 μmol/L to 80 nmol/L (12-fold) in a colony formation assay. 3-Oxo-C12-(l)-HSL enhances the activity of 5-fluorodeoxyuridine, tomudex, and taxol but not the activity of 5-fluorouridine, methotrexate or Adriamycin. The unexpected interaction with taxol probably results from effects of the AHL on tubulin expression. Differences in taxol sensitivity, tubulin, and cellular morphology between H630 and the thymidylate synthase and rTSβ-overproducing, 5-FU-resistant H630-1 cell line as determined by colony formation assays, Western analysis of one-dimensional and two-dimensional gels, and photomicroscopy confirm that cytoskeletal changes are induced by the AHL or by rTS signaling. Isozyme differences in thymidylate synthase and rTSβ also exist in the two cell lines. Phosphorylation of rTSβ amino acid S121 is shown to occur and is decreased at least 10-fold in the drug-resistant cells. The data presented provide support for further investigations of rTS signaling mimics as enhancers to thymidylate synthase–directed chemotherapy, evidence that the phosphorylation state of rTSβ may be a marker for 5-FU resistance and a previously unrealized relationship between rTS signaling and the cytoskeleton.
Activation of the Canonical Wnt Pathway during Genital Keratinocyte Transformation: A Model for Cervical Cancer Progression
Authors: Üren Aykut , Fallen Shannon , Yuan Hang , Usubütün Alp , Küçükali Türkan , Schlegel Richard , Toretsky Jeffrey A. 
Published: September 2005

Abstract
Cervical carcinoma, the second leading cause of cancer deaths in women worldwide, is associated with human papillomavirus (HPV). HPV-infected individuals are at high risk for developing cervical carcinoma; however, the molecular mechanisms that lead to the progression of cervical cancer have not been established. We hypothesized that in a multistep carcinogenesis model, HPV provides the initial hit and activation of canonical Wnt pathway may serve as the second hit. To test this hypothesis, we evaluated the canonical Wnt pathway as a promoting factor of HPV-induced human keratinocyte transformation. In this in vitro experimental cervical carcinoma model, primary human keratinocytes immortalized by HPV were transformed by SV40 small-t (smt) antigen. We show that smt-transformed cells have high cytoplasmic β-catenin levels, a hallmark of activated canonical Wnt pathway, and that activation of this pathway by smt is mediated through its interaction with protein phosphatase-2A. Furthermore, inhibition of downstream signaling from β-catenin inhibited the smt-induced transformed phenotype. Wnt pathway activation transformed HPV-immortalized primary human keratinocytes even in the absence of smt. However, activation of the Wnt pathway in the absence of HPV was not sufficient to induce transformation. We also detected increased cytoplasmic and nuclear staining of β-catenin in invasive cervical carcinoma samples from 48 patients. We detected weak cytoplasmic and no nuclear staining of β-catenin in 18 cases of cervical dysplasia. Our results suggest that the transformation of HPV expressing human keratinocytes requires activation of the Wnt pathway and that this activation may serve as a screening tool in HPV-positive populations to detect malignant progression.
Cyclin D1 Antagonizes BRCA1 Repression of Estrogen Receptor α Activity
Authors: Wang Chenguang , Fan Saijun , Li Zhiping , Fu Maofu , Rao Mahadev , Ma Yongxian , Lisanti Michael P. , Albanese Chris , Katzenellenbogen Benita S. , Kushner Peter J. , Weber Barbara , Rosen Eliot M. , Pestell Richard G. 
Published: September 2005

Abstract
The cyclin D1 gene is frequently overexpressed in human breast cancer and is capable of inducing mammary tumorigenesis when overexpressed in transgenic mice. The BRCA1 breast tumor susceptibility gene product inhibits breast cancer cellular growth and the activity of several transcription factors. Herein, cyclin D1 antagonized BRCA1-mediated repression of estrogen receptor α (ERα)–dependent gene expression. Cyclin D1 repression of BRCA1 function was mediated independently of its cyclin-dependent kinase, retinoblastoma protein, or p160 (SRC-1) functions in human breast and prostate cancer cells. In vitro, cyclin D1 competed with BRCA1 for ERα binding. Cyclin D1 and BRCA1 were both capable of binding ERα in a common region of the ERα hinge domain. A novel domain of cyclin D1, predicted to form a helix-loop-helix structure, was required for binding to ERα and for rescue of BRCA1-mediated ERα transcriptional repression. In chromatin immunoprecipitation assays, 17β-estradiol (E2) enhanced ERα and cyclin D1 recruitment to an estrogen response element (ERE). Cyclin D1 expression enhanced ERα recruitment to an ERE. E2 reduced BRCA1 recruitment and BRCA1 expression inhibited E2-induced ERα recruitment at 12 hours. Cyclin D1 expression antagonized BRCA1 inhibition of ERα recruitment to an ERE, providing a mechanism by which cyclin D1 antagonizes BRCA1 function at an ERE. As cyclin D1 abundance is regulated by oncogenic and mitogenic signals, the antagonism of the BRCA1-mediated ERα repression by cyclin D1 may contribute to the selective induction of BRCA1-regulated target genes.