bluuebunny/crossref_metadata_2025_split huggingface dataset:
High SEPT9_v1 Expression in Human Breast Cancer Cells Is Associated with Oncogenic Phenotypes
Authors: Gonzalez Maria E. , Peterson Esther A. , Privette Lisa M. , Loffreda-Wren Janice L. , Kalikin Linda M. , Petty Elizabeth M. 
Published: September 2007

Abstract
Altered expression of the human septin gene, SEPT9, and its murine homologue, Sept9, has been implicated in neoplasia. However, their role(s) in oncogenesis remains poorly understood. We found amplification of SEPT9 in 67% of breast cancer cells (BCC) when compared with immortalized human mammary epithelial cells (IHMEC) as well as high levels of SEPT9 expression in the majority (61%) of the BCCs studied, unlike IHMECs. Expression profiling of variant SEPT9 transcripts and translated products revealed that high expression of the variant, SEPT9_v1, in contrast to other variants, was widespread in BCCs (55% of the BCCs) but not in IHMECs. High expression of SEPT9_v1 was also observed in primary breast cancer samples by immunohistochemical studies. We subsequently examined the phenotypic consequences of SEPT9_v1 expression in human breast cells. Retroviral expression of SEPT9_v1 in IHMEC cell culture models showed that SEPT9_v1 accelerated growth kinetics, stimulated cell motility, promoted invasion in Matrigel Transwell assays, increased genomic instability with the development of aneuploidy, and stimulated morphologic changes. Significant cytokinesis defects and disruption of tubulin microfilaments were also observed by immunofluorescence when SEPT9_v1 was ectopically expressed in IHMECs. Furthermore, SEPT9_v1 markedly enhanced neoplastic transformation in Hs578T cells, a BCC with no endogenous expression of the SEPT9_v1 isoform. Small interfering RNA–mediated and short hairpin RNA–mediated inhibition of SEPT9_v1 expression in two BCCs with high levels of endogenous SEPT9_v1 expression inhibited neoplastic growth properties of the cells. Taken together, our findings suggest that increased SEPT9_v1 expression contributes to the malignant pathogenesis of some breast tumors. [Cancer Res 2007;67(18):8554–11]
Identification of Tumorsphere- and Tumor-Initiating Cells in HER2/Neu-Induced Mammary Tumors
Authors: Liu Jeff C. , Deng Tao , Lehal Rajwinder S. , Kim Jinny , Zacksenhaus Eldad 
Published: September 2007

Abstract
A variety of human malignancies, including breast cancer, are thought to be organized in a hierarchy, whereby a relatively minor population of tumor initiating cells (TIC) is responsible for tumor growth and the vast majority of remaining cells is nontumorigenic. Analysis of TICs in model systems of breast cancer would offer uniform and accessible source of tumor cells and the power of mouse genetics to dissect these rare cells. The HER2/Neu proto-oncogene is overexpressed in an aggressive form of human breast cancer. Mouse mammary tumor virus (MMTV)-Neu transgenic mice develop mammary tumors that mimic human HER2 subtype breast cancer. Here, we report on the functional identification of mouse HER2/Neu TICs that can induce tumors after transplantation into the mammary gland of recipient mice. Secondary tumors formed after injecting MMTV-Neu TICs resemble primary tumors in the original transgenic mice and are organized in a hierarchy containing TICs as well as their nontumorigenic descendants. To study MMTV-Neu TICs in vitro, we grew tumorspheres under nonadherent culture conditions. Tumorsphere forming units (TFU) capable of producing tumorspheres retained tumorigenic potential and were indistinguishable by several criteria from TICs. Interestingly, MMTV-Neu TICs and TFUs were committed to the luminal cell fate when induced to differentiate in vitro. Our data define reproducible characteristics of the MMTV-Neu TIC and TFU, which help to explain marker expression profiles of HER2-positive breast cancer. In addition, the similarity between TICs and TFUs in this system provides a rationale for TFU-based screens to target tumor-initiating cells in HER2+ breast cancer. [Cancer Res 2007;67(18):8671–81]
Regulation of Phosphoglucose Isomerase/Autocrine Motility Factor Activities by the Poly(ADP-Ribose) Polymerase Family-14
Authors: Yanagawa Takashi , Funasaka Tatsuyoshi , Tsutsumi Soichi , Hu Huankai , Watanabe Hideomi , Raz Avraham 
Published: September 2007

Abstract
Phosphoglucose isomerase (PGI; EC 5.3.1.9) is a ubiquitous cytosolic enzyme essential for glycolysis and gluconeogenesis. PGI is a multifunctional dimeric protein that extracellularly acts as a cytokine [autocrine motility factor (AMF)] eliciting mitogenic, motogenic, and differentiation functions through binding to its cell surface receptor gp78/AMF receptor (AMFR). AMFR contains a seven-transmembrane domain with RING-H2 and leucine zipper motifs showing ubiquitin protein ligase (E3) activity and is exposed on the endoplasmic reticulum surface. Augmented expressions of both PGI/AMF and AMFR have been implicated in tumor progression and metastasis, and an intracellular binding partner of PGI/AMF is expected to regulate in part its diverse biological functions. Thus, we screened a cDNA library using a yeast two-hybrid system to search for interacting protein(s) and report on the finding of poly(ADP-ribose) polymerase-14 (PARP-14) to be a binding partner with PGI/AMF. PARP-14–PGI/AMF interaction was confirmed by coimmunoprecipitation and immunolocalization. We also report that PGI/AMF degradation is mainly regulated by the ubiquitin-lysosome system and RNA interference experiments revealed that PARP-14 inhibits PGI/AMF ubiquitination, thus contributing to its stabilization and secretion. This newly characterized PARP-14 protein should assist in understanding the regulation of PGI/AMF intracellular function(s) and may provide a new therapeutic target for inhibition of PGI/AMF inducing tumor cell migration and invasion during metastasis. [Cancer Res 2007;67(18):8682–9]
Deletion of the AU-Rich RNA Binding Protein Apobec-1 Reduces Intestinal Tumor Burden in Apcmin Mice
Authors: Blanc Valerie , Henderson Jeffrey O. , Newberry Rodney D. , Xie Yan , Cho Soo-Jin , Newberry Elizabeth P. , Kennedy Susan , Rubin Deborah C. , Wang Hanlin L. , Luo Jianyang , Davidson Nicholas O. 
Published: September 2007

Abstract
The RNA-specific cytidine deaminase apobec-1 is an AU-rich RNA binding protein that binds the 3′ untranslated region (UTR) of cyclooxygenase-2 (Cox-2) mRNA and stabilizes its turnover in vitro. Cox-2 overexpression accompanies intestinal adenoma formation in both humans and mice. Evidence from both genetic deletion studies as well as from pharmacologic inhibition has implicated Cox-2 in the development of intestinal adenomas in experimental animals and in adenomas and colorectal cancer in humans. Here, we show that small intestinal adenoma formation is dramatically reduced in compound Apcmin/+ apobec-1−/− mice when compared with the parental Apcmin/+ strain. This reduced tumor burden was found in association with increased small intestinal apoptosis and reduced proliferation in small intestinal crypt-villus units from compound Apcmin/+ apobec-1−/− mice. Intestinal adenomas from compound Apcmin/+ apobec-1−/− mice showed a &lt;2-fold increase in Cox-2 mRNA abundance and reduced prostaglandin E2 content compared with adenomas from the parental Apcmin/+ strain. In addition, there was reduced expression in adenomas from compound Apcmin/+ apobec-1−/− mice of other mRNAs (including epidermal growth factor receptor, peroxisome proliferator–activated receptor δ, prostaglandin receptor EP4, and c-myc), each containing the apobec-1 consensus binding site within their 3′-UTR. Adenovirus-mediated apobec-1 introduction into HCA-7 (colorectal cancer) cells showed a dose-dependent increase in Cox-2 protein and stabilization of endogenous Cox-2 mRNA. These findings suggest that deletion of apobec-1, by modulating expression of AU-rich RNA targets, provides an important mechanism for attenuating a dominant genetic restriction point in intestinal adenoma formation. [Cancer Res 2007;67(18):8565–73]
Protein Kinase Cε Interacts with Signal Transducers and Activators of Transcription 3 (Stat3), Phosphorylates Stat3Ser727, and Regulates Its Constitutive Activation in Prostate Cancer
Authors: Aziz Moammir H. , Manoharan Herbert T. , Church Dawn R. , Dreckschmidt Nancy E. , Zhong Weixiong , Oberley Terry D. , Wilding George , Verma Ajit K. 
Published: September 2007

Abstract
Prostate cancer is the most common type of cancer in men and ranks second only to lung cancer in cancer-related deaths. The management of locally advanced prostate cancer is difficult because the cancer often becomes hormone insensitive and unresponsive to current chemotherapeutic agents. Knowledge about the regulatory molecules involved in the transformation to androgen-independent prostate cancer is essential for the rational design of agents to prevent and treat prostate cancer. Protein kinase Cε (PKCε), a member of the novel PKC subfamily, is linked to the development of androgen-independent prostate cancer. PKCε expression levels, as determined by immunohistochemistry of human prostate cancer tissue microarrays, correlated with the aggressiveness of prostate cancer. The mechanism by which PKCε mediates progression to prostate cancer remains elusive. We present here for the first time that signal transducers and activators of transcription 3 (Stat3), which is constitutively activated in a wide variety of human cancers, including prostate cancer, interacts with PKCε. The interaction of PKCε with Stat3 was observed in human prostate cancer, human prostate cancer cell lines (LNCaP, DU145, PC3, and CW22rv1), and prostate cancer that developed in transgenic adenocarcinoma of mouse prostate mice. In reciprocal immunoprecipitation/blotting experiments, prostatic Stat3 coimmunoprecipitated with PKCε. Localization of PKCε with Stat3 was confirmed by double immunofluorescence staining. The interaction of PKCε with Stat3 was PKCε isoform specific. Inhibition of PKCε protein expression in DU145 cells using specific PKCε small interfering RNA (a) inhibited Stat3Ser727 phosphorylation, (b) decreased both Stat3 DNA-binding and transcriptional activity, and (c) decreased DU145 cell invasion. These results indicate that PKCε activation is essential for constitutive activation of Stat3 and prostate cancer progression. [Cancer Res 2007;67(18):8828–38]
Repression of Vascular Endothelial Growth Factor Expression by the Zinc Finger Transcription Factor ZNF24
Authors: Harper Jay , Yan Li , Loureiro Robyn M. , Wu Iinmin , Fang Jianmin , D'Amore Patricia A. , Moses Marsha A. 
Published: September 2007

Abstract
Vascular endothelial growth factor (VEGF) is a potent stimulator of angiogenesis. Although many positive regulators of VEGF have been identified, relatively little is known regarding the negative regulation of VEGF expression. We identified a zinc finger transcription factor, ZNF24, that may repress VEGF transcription. An inverse correlation between expression of VEGF and ZNF24 was observed in a series of independent studies. ZNF24 was up-regulated in angiogenic tumor nodules where VEGF expression is significantly decreased compared with preangiogenic nodules. In human breast carcinoma cells cultured under normoxic conditions, ZNF24 levels were significantly up-regulated whereas VEGF levels were low. In contrast, VEGF was significantly increased in hypoxic cells whereas ZNF24 was down-regulated. The same inverse correlation between ZNF24 and VEGF was also observed in 70% of matched cDNA pairs of normal and malignant tissues from human colon and breast biopsies. Overexpression of ZNF24 resulted in a significant down-regulation of VEGF, whereas silencing of ZNF24 with small interfering RNA led to increased VEGF expression. Cotransfection of ZNF24 and a VEGF promoter luciferase reporter construct in MDA-MB-231 cells resulted in a significant decrease in VEGF promoter activity. Taken together, these data suggest that ZNF24 is involved in negative regulation of VEGF and may represent a novel repressor of VEGF transcription. [Cancer Res 2007;67(18):8736–41]
Tie2-Expressing Monocytes and Tumor Angiogenesis: Regulation by Hypoxia and Angiopoietin-2
Authors: Lewis Claire E. , De Palma Michele , Naldini Luigi 
Published: September 2007

Abstract
Recent findings indicate that tumor-associated macrophages are important drivers of tumor angiogenesis. Here, we review the essential role played by Tie2-expressing monocytes (TEM) in this phenomenon. TEMs are present in human blood and tumors and their elimination in various tumor models suppresses tumor angiogenesis. A ligand for Tie2, angiopoietin-2 (Ang-2), is produced by angiogenic tumor vessels and is a chemoattractant for TEMs. Hypoxia up-regulates Tie2 expression on TEMs and, together with Ang-2, down-regulates their antitumor functions. Learning more about the regulation of TEMs by the tumor microenvironment may yield new strategies to ablate the tumor vasculature. [Cancer Res 2007;67(18):8429–32]
Relationship between B7-H4, Regulatory T Cells, and Patient Outcome in Human Ovarian Carcinoma
Authors: Kryczek Ilona , Wei Shuang , Zhu Gefeng , Myers Leann , Mottram Peter , Cheng Pui , Chen Lieping , Coukos George , Zou Weiping 
Published: September 2007

Abstract
B7-H4 is a recently identified B7 family member. We previously showed that ovarian tumor and associated macrophages expressed B7-H4; tumor B7-H4+ macrophages and CD4+CD25+FOXP3+ regulatory T cells (Treg cells) suppressed tumor-associated antigen–specific T-cell immunity. To determine the pathologic relationship between B7-H4, macrophages, and Treg cells in the tumor environment, in addition to Treg cell numbers, we quantified B7-H4 expression in the tumor and tumor-associated macrophages in 103 patients with ovarian carcinoma. We observed that the intensity of B7-H4 expression in macrophages was significantly correlated with Treg cell numbers in the tumor. Further, both Treg cells and macrophage B7-H4, but not tumor B7-H4, were negatively associated with patient outcome. Tumor Treg cells enabled macrophages to spontaneously produce interleukin (IL)-10 and IL-6. Tumor macrophages stimulated B7-H4 expression in an autocrine manner through IL-10 and IL-6. Our previous work showed that tumor-associated macrophages spontaneously produced chemokine CCL22 to mediate Treg cell trafficking into tumor, and Treg cells induced B7-H4 on antigen-presenting cells (APC) including macrophages. Altogether, our data support the concept that there is a mechanistic interaction between Treg cells and macrophage, and that Treg cells may convey the suppressive activity to APCs through B7-H4 induction in human ovarian cancer. [Cancer Res 2007;67(18):8901–05]
Nitric Oxide Radicals Choreograph a Radioadaptive Response
Authors: Matsumoto Hideki , Takahashi Akihisa , Ohnishi Takeo 
Published: September 2007

Abstract
The reduced biological effects of radiation exposure seen in cells after conditioning exposures to a low dose or at a low-dose rate (i.e., the acquisition of resistance against high-dose radiation) is called the “radioadaptive response” and many studies concerning this phenomenon have been reported since the 1980s. Radioadaptive responses have been observed using various end points, such as chromosomal aberrations, mutations, and clonogenic survival. However, the mechanisms of the radioadaptive response are not fully known. Here, we show that radiation-induced nitric oxide (NO) radicals contribute to the induction of radioresistance as determined by cell survival after a subsequent high-dose exposure. An accumulation of inducible NO synthase was produced, and the concentration of nitrite in the culture medium increased when cells were exposed to γ-rays at a low-dose rate or to X-rays for a low dose followed by an acute high-dose X-irradiation. In addition, the induction of radioresistance was not observed in the presence of an inhibitor of inducible NO synthase or a scavenger of NO radicals. Moreover, radioresistance was observed when cultures were treated with a NO radical–generating agent. These findings suggest that NO radicals are an initiator of the radioadaptive response. [Cancer Res 2007;67(18):8574–9]
MicroRNA Signatures in Human Ovarian Cancer
Authors: Iorio Marilena V. , Visone Rosa , Di Leva Gianpiero , Donati Valentina , Petrocca Fabio , Casalini Patrizia , Taccioli Cristian , Volinia Stefano , Liu Chang-Gong , Alder Hansjuerg , Calin George A. , Ménard Sylvie , Croce Carlo M. 
Published: September 2007

Abstract
Epithelial ovarian cancer (EOC) is the sixth most common cancer in women worldwide and, despite advances in detection and therapies, it still represents the most lethal gynecologic malignancy in the industrialized countries. Unfortunately, still relatively little is known about the molecular events that lead to the development of this highly aggressive disease. The relatively recent discovery of microRNAs (miRNA), a class of small noncoding RNAs targeting multiple mRNAs and triggering translation repression and/or RNA degradation, has revealed the existence of a new level of gene expression regulation. Multiple studies involving various types of human cancers proved that miRNAs have a causal role in tumorigenesis. Here we show that, in comparison to normal ovary, miRNAs are aberrantly expressed in human ovarian cancer. The overall miRNA expression could clearly separate normal versus cancer tissues. The most significantly overexpressed miRNAs were miR-200a, miR-141, miR-200c, and miR-200b, whereas miR-199a, miR-140, miR-145, and miR-125b1 were among the most down-modulated miRNAs. We could also identify miRNAs whose expression was correlated with specific ovarian cancer biopathologic features, such as histotype, lymphovascular and organ invasion, and involvement of ovarian surface. Moreover, the levels of miR-21, miR-203, and miR-205, up-modulated in ovarian carcinomas compared with normal tissues, were significantly increased after 5-aza-2′-deoxycytidine demethylating treatment of OVCAR3 cells, suggesting that the DNA hypomethylation could be the mechanism responsible for their overexpression. Our results indicate that miRNAs might play a role in the pathogenesis of human EOC and identify altered miRNA gene methylation as a possible epigenetic mechanism involved in their aberrant expression. [Cancer Res 2007;67(18):8699–707]
In Non-neoplastic Barrett's Epithelial Cells, Acid Exerts Early Antiproliferative Effects through Activation of the Chk2 Pathway
Authors: Zhang Hui-Ying , Zhang Xi , Hormi-Carver Kathy , Feagins Linda A. , Spechler Stuart J. , Souza Rhonda F. 
Published: September 2007

Abstract
Acid exerts pro-proliferative effects in Barrett's-associated esophageal adenocarcinoma cells. In non-neoplastic Barrett's epithelial (BAR-T) cells, in contrast, we have shown that acid exposure has antiproliferative effects. To explore our hypothesis that the acid-induced, antiproliferative effects are mediated by alterations in the proteins that regulate the G1-S cell cycle checkpoint, we exposed non-neoplastic Barrett's cells to acidic media (pH 4.0) and analyzed G1-S checkpoint proteins' expression, phosphorylation, and activity levels by Western blot. We studied acid effects on growth (by cell counts), proliferation (by flow cytometry and bromodeoxyuridine incorporation), cell viability (by trypan blue staining), and apoptosis (by annexin V staining), and we used caffeine and small interfering RNA to assess the effects of checkpoint kinase 2 (Chk2) inhibition on G1-S progression. Acid exposure significantly decreased cell numbers without affecting cell viability and with only a slight increase in apoptosis. Within 2 h of acid exposure, there was a delay in progression through the G1-S checkpoint that was associated with increased phosphorylation of Chk2, decreased levels of Cdc25A, and decreased activity of cyclin E–cyclin-dependent kinase 2; by 4 h, a continued delay at G1-S was associated with increased expression of p53 and p21. Caffeine and Chk2 siRNA abolished the acid-induced G1-S delay at 2 but not at 4 h. We conclude that acid exposure in non-neoplastic BAR-T cells causes early antiproliferative effects that are mediated by the activation of Chk2. Thus, we have elucidated a mechanism whereby acid can exert disparate effects on proliferation in neoplastic and non-neoplastic BAR-T cells. [Cancer Res 2007;67(18):8580–7]
SV40 Multiple Tissue Infection and Asbestos Exposure in a Hyperendemic Area for Malignant Mesothelioma
Authors: Comar Manola , Rizzardi Clara , de Zotti Renata , Melato Mauro , Bovenzi Massimo , Butel Janet S. , Campello Cesare 
Published: September 2007

Abstract
To assess the presence of SV40 in malignant mesothelioma tissue, 19 formalin-fixed paraffin-embedded pleural cancer samples of patients from a hyperendemic area of northeastern Italy were analyzed retrospectively. A total of 48 other tissues from the malignant mesothelioma subjects were investigated. The SV40 load was determined by real-time quantitative PCR. Exposure to asbestos was evaluated through a careful review of the occupational history of patients, supplemented by histology and isolation of asbestos bodies. Three of 19 (15.8%) malignant mesothelioma tissues harbored SV40 genomic signals. Two patients with SV40-positive malignant mesothelioma had viral sequences in another tissue. Overall, 3 of 18 (16.7%) normal liver tissues tested positive for SV40, as did 1 of 8 (12.5%) kidney tissues. SV40 viral loads were higher in malignant mesothelioma than in normal cells (P = 0.045). This survey shows that SV40 sustains infections in multiple tissues in malignant mesothelioma patients from a geographic area affected with asbestos-related mesothelioma. [Cancer Res 2007;67(18):8456–4]
TFAP2C Controls Hormone Response in Breast Cancer Cells through Multiple Pathways of Estrogen Signaling
Authors: Woodfield George W. , Horan Annamarie D. , Chen Yizhen , Weigel Ronald J. 
Published: September 2007

Abstract
Breast cancers expressing estrogen receptor-α (ERα) are associated with a favorable biology and are more likely to respond to hormonal therapy. In addition to ERα, other pathways of estrogen response have been identified including ERβ and GPR30, a membrane receptor for estrogen, and the key mechanisms regulating expression of ERs and hormone response remain controversial. Herein, we show that TFAP2C is the key regulator of hormone responsiveness in breast carcinoma cells through the control of multiple pathways of estrogen signaling. TFAP2C regulates the expression of ERα directly by binding to the ERα promoter and indirectly via regulation of FoxM1. In so doing, TFAP2C controls the expression of ERα target genes, including pS2, MYB, and RERG. Furthermore, TFAP2C controlled the expression of GPR30. In distinct contrast, TFAP2A, a related factor expressed in breast cancer, was not involved in estrogen-mediated pathways but regulated expression of genes controlling cell cycle arrest and apoptosis including p21CIP1 and IGFBP-3. Knockdown of TFAP2C abrogated the mitogenic response to estrogen exposure and decreased hormone-responsive tumor growth of breast cancer xenografts. We conclude that TFAP2C is a central control gene of hormone response and is a novel therapeutic target in the design of new drug treatments for breast cancer. [Cancer Res 2007;67(18):8439–43]