bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3894: Copy number alterations in urothelial carcinomas: Their clinicopathological significance and correlation with DNA methylation alterations
Authors: Nishiyama Naotaka , Arai Eri , Nagashio Ryo , Fujimoto Hiroyuki , Hosoda Fumie , Shibata Tatsuhiro , Tsukamoto Taiji , Yokoi Sana , Imoto Issei , Inazawa Johji , Kanai Yae
Published: June 2012

Purpose: The aim of this study was to clarify the genetic backgrounds underlying the clinicopathological characteristics of urothelial carcinomas (UCs).

Experimental Design: We analyzed copy number alterations by array comparative genomic hybridization analysis using a high-resolution (244K) oligonucleotide array, DNA methylation alterations on a genome-wide scale using bacterial artificial chromosome array-based methylated CpG island amplification, and DNA methylation status on C-type CpG islands using bisulfite modification in 49 samples of UCs of the urinary bladder, ureter and renal pelvis. The clinicopathological significance of copy number alterations and the correlations between alterations of copy number and those of DNA methylation were examined.

Results: Losses of 2q33.3-q37.3, 4p15.1-q26 and 5q13.3-q35.2 and gains of 7p11.2-q11.23 and 20q13.11-q13.31 were correlated with higher histological grade, and gain of 7p21.2-p21.1 was correlated with deeper invasion. Losses of 6q14.1-q27 and 17p13-q11.1 and gains of 19q13.11-q13.12 and 20q13.12-q13.33 were correlated with lymph vessel involvement. Loss of 16p12.2-p12.1 and gains of 3q26.31-q29 and 20q13.2-q13.33 were correlated with vascular involvement. Losses of 5q14.1-q23.2, 6q14.1-q27, 8p22-p21.3, 11q13.5-q14.1 and 15q11.2-q22.2 and gains of 3q27.3-q29, 7p11.2-q11.22, 10p13-p12.33, 12q24.31 and 19q13.11-q13.2 were correlated with the development of aggressive non-papillary UCs. Losses of 1p33-p31.1, 2q22.1-q23.1, 10q11.23-q21.1 and 15q21.3 were correlated with tumor recurrence. Unsupervised hierarchical clustering analysis based on copy number alterations clustered UCs into three subclasses, clusters A, B1 and B2: copy number alterations associated with genome-wide DNA hypomethylation, regional DNA hypermethylation on C-type CpG islands associated with chromosomal losses, and genome-wide DNA hypo- and hypermethylation, were accumulated in clusters A, B1 and B2, respectively.

Conclusions: There is a need to explore tumor-related genes that may encode potential therapeutic targets at chromosomal loci where copy number alterations are correlated with clinicopathological parameters reflecting the malignant potential of UCs. Chromosomal loci where copy number alterations are correlated with UC recurrence may be potential indicators of prognosis. Both genetic and epigenetic events appear to accumulate during urothelial carcinogenesis, reflecting the clinicopathological diversity and histological heterogeneity of UCs.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3894. doi:10.1158/1538-7445.AM2011-3894
Abstract 3896: The interaction between BRCA2 and DSS1 is crucial for homologous recombination through controlling protein localization
Authors: Egashira Akinori , Siaud Nicolas , Christ Nicole , Morita Masaru , Kakeji Yoshihiro , Jasin Maria , Maehara Yoshihiko
Published: June 2012

The BRCA2 tumor suppressor plays an important role in the repair of DNA damage by homologous recombination (HR). Human BRCA2 is huge protein and is composed of several domains including DNA/DSS1 binding domain (DBD). DSS1 has shown to be important for HR in various organisms but the precise function of DSS1 through the interaction between BRCA2 is still unclear in mammalian cells. To clarify the role of DSS1-BRCA2 interaction in the repair of DNA damage, we put several mutations into BRCA2 peptides which could restore HR in Brca2 mutant hamster cells. The mutant BRCA2 peptides with mutation which reduced DSS1 binding impaired the ability of these peptides to promote HR when compared to wild type peptides. It is of great interest that the excessive DSS1 expression partially restored HR activity of BRCA2 mutants which weakly bind DSS1. Furthermore, excessive DSS1 expression facilitate the nuclear localization of wild type BRCA2 peptide. On the other hand, excessive DSS1 expression had no effect for neither HR activity nor the subcellular localization of mutant BRCA2 peptide that could not bind to DSS1. Knockdown of DSS1 by siRNA also showed reduced HR and nuclear localization of BRCA2 protein. In conclusion, one of the essential functions of DSS1 in HR through the interaction between BRCA2 might be a regulation of BRCA2 subcellular localization.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3896. doi:10.1158/1538-7445.AM2011-3896
Abstract 3897: A difference of HER-2 amplification index between luminal B and HER2 enriched subgroup
Authors: Lee Soohyeon , Koo Ja Seung , Park Byung Woo , Kim Seung Il , Park Se Ho , Kim Gun Min , Kim Se Hyun , Kim Joo Hang , Sohn Ju Hyuk
Published: June 2012

Background: The aim of this study was to compare the HER2 gene amplification index (AI) of luminal B and HER-2 enriched breast cancers using fluorescence in situ hybridization (FISH).

Methods: Out of 753 patients with breast cancer who were tested HER2 status by FISH between Jan 2004 to Dec 2009, 224 HER2 amplified patients were available for this study. HER2-amplified breast cancers constitute a heterogenous group that may be subdivided according to their ER status: HER2 amplified ER-positive breast carcinomas that fall into the luminal B group; and HER2 amplified ER-negative cancers which form a distinct molecular subtype, known as the HER2 enriched group according to hormone status by immunohistochemistry and HER2 amplification confirmed as HER2/CEP17 ratio by FISH. A difference of HER2 AI was analyzed between luminal B and HER-2 enriched group. Clinicopathologic parameters were analyzed.

Results: Among the HER2 amplified patients, the proportion of luminal B and HER2 breast cancer was 53.5% (N=120) and 46.5% (N=104), respectively. Early breast cancer patients were 84.8% (N=190) and metastatic breast cancer patients were 15.2% (N=34). HER-2 AI of luminal B group and HER2 enriched group were 4.99 and 5.84 respectively, which values showed the quantitative difference statistically significant (p=0.003). However, increasing value of HER2 AI was not associated with a better overall survival or progression free survival. In luminal B group, a significant difference of HER2 AI between ER/PR +/+ subgroup and ER/PR +/- subgroup existed which were 4.02 and 5.32, respectively (p=0004).

Conclusions: The HER2 AI of HER2 enriched group was higher than that of luminal B group statistically significant. It was not clear whether the extent of HER-2 amplification relates to the survival benefit of treatment in HER-2 positive breast cancer. Further research to understand how the level of HER2 amplification is related to prognosis is warranted in order to understand the breast cancer biology associated with the intrinsic subtypes.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3897. doi:10.1158/1538-7445.AM2011-3897
Abstract 3899: Anti-cancer drugs increases microsatellite instability in human colorectal cancer cells
Authors: Chang Christina L. , Chiu Chien-Yuan , Chi Jhih-Ying , Wu Chang-Lin Wu Chang-Lin , Li I-Chen , Jian Siao-Ru
Published: June 2012

Manifested as microsatellite instability (MSI), DNA mismatch repair (MMR) deficiency is known to contribute to colorectal cancer pathogenesis and drug resistance. Growing evidence indicates that MMR deficiency is also widespread among secondary cancers in patients who have received chemotherapy. It is unclear what chemotherapeutic agents cause MMR deficiency. In this study, we aim at identifying the MSI-inducing anti-cancer drugs. To facilitate the identification, we developed an in-vivo dual fluorescent reporter system in a human colorectal cancer cell model using RFP that contains a microsatellite as the MSI reporter and GFP as the cell label. Based on flow cytometric analysis, we found that test anti-cancer drugs increased the MSI frequency in a dose-dependent manner. This was confirmed by fluorescent microscopy. With the NCI recommended markers, we detected a low frequency of MSI in cells after treated with a couple, but not all, of test anti-cancer drugs. Our cell-based MSI reporter assay will facilitate large scale screens of MSI-inducing and MSI-reducing drugs/compounds, which might provide treatment strategies for controlling therapy-related secondary cancers.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3899. doi:10.1158/1538-7445.AM2011-3899
Abstract 3971: Carcinogenesis of intraductal papillary mucinous neoplasm of the pancreas: Loss of microRNA-101 promotes overexpression of histone methyltransferase EZH2
Authors: Nakahara Osamu , Takamori Hiroshi , Sakamoto Yasuo , Tanaka Hiroshi , Chikamoto Akira , Horino Kei , Beppu Toru , Honda Yumi , Iyama Ken-ichi , Baba Hideo
Published: June 2012

BACKGROUND: Intraductal papillary mucinous neoplasms (IPMNs) include various degree of dysplasia, and are supposed to be one of the precursors of pancreatic ductal adenocarcinoma (PDCA), however, IPMN carcinogenesis has not yet been established. MicroRNAs (miRNA) may be directly implicated in some carcinogenic process. These miRNAs can function as tumor suppressors or oncogenes. Enhancer of zeste homolog 2 (EZH2) contributes to the epigenetic silencing of target genes, and plays a pivotal role in the etiology of tumorigenisity in several cancers.

PURPOSE: This study aimed to (1) evaluate whether expression of EZH2 promotes neoplastic progression of IPMN and PDCA, and (2) elucidate regulation of EZH2 expression by miR-101.

METHODS: EZH2 mRNA and protein expression was investigated in eight human pancreatic cancer cell lines (PANC-1, PK8, PK9, PK-59, KLM-1, MIA PaCa2, Hs-700T, PK-45P) by PCR and western blotting. Pre-miR-101, and anti-miR-101 was transfected into pancreatic cancer cells to elucidate regulation of EZH2 by miR-101. To evaluate whether EZH2 modulates malignant progression of IPMN, EZH2 expression in both benign and malignant IPMN was examined in 54 patients by immunohistochemistry. Next, we collected malignant and benign cells from formalin-fixed paraffin-embedded samples of IPMNs using laser capture microdissection, and extracted RNA. MiR-101 expression in IPMN was assessed using real-time PCR.

RESULTS: All pancreatic cancer cell lines expressed EZH2 mRNA and protein. The induction of miR-101 by transfection of pre-miR-101 in MIA PaCa-2 was closely related to a reduction in EZH2 protein production compared with control, whereas there was little difference in the expression of EZH2 mRNA. Anti-miR-101 transfected pancreatic cancer cells showed increase in EZH2 protein, while EZH2 mRNA level was not elevated. Immunohistochemistry revealed that the expression of EZH2 was significantly higher in malignant than benign IPMN. Expression of MiR-101 was significantly lower in malignant than benign IPMN.

CONCLUSIONS: MiR-101 targets EZH2 at the posttranscriptional level, and loss of miR-101 could be a trigger for the adenoma-carcinoma sequence of IPMN by up-regulation of EZH2. This study suggests miR-101- EZH2 blockade as a potential therapeutic target in IPMN carcinogenesis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3971. doi:10.1158/1538-7445.AM2011-3971
Abstract 3981: miR-708 induces apoptosis and suppresses tumorigenicity in renal cell carcinomas
Authors: Saini Sharanjot , Yamamura Soichiro , Majid Shahana , Shahryari Varahram , Deng Guoren , Hirata Hiroshi , Ueno Koji , Chang Inik , Tanaka Yuichiro , Dahiya Rajvir
Published: June 2012

MicroRNAs (miRNAs) constitute an evolutionarily conserved class of small non-coding RNAs that primarily regulate gene expression at the post-transcriptional level via sequence-specific interaction with the 3’-untranslated regions of cognate mRNA targets. Recent evidence indicates that dysregulated miRNA expression leads to tumorigenesis and miRNAs have been implicated to function as either tumor suppressors or oncogenes. The main objective of the present study was to identify miRNA genes that regulate renal cell carcinomas (RCC). Towards this, we performed microRNA expression profiling in normal immortalized renal cell line (HK2) and primary renal cancer cell lines (A498 and Caki2) and identified that miR-708 expression is significantly attenuated in renal cancer cell lines. This attenuation was validated by RT-PCR and in situ hybridization analysis of miR-708 in RCC tissue specimens. Further, trichostatin A, a pharmacological inhibitor of histone deacetylases, strongly increased miR-708 levels in cell lines from renal cancer suggesting that epigenetic silencing may lead to miR-708 downregulation in RCC. To evaluate the functional significance of decreased miR-708 expression, miR-708 was reintroduced in renal cancer cell lines followed by functional assays. Overexpression of miR-708 in the A498 cell line leads to significant decreases in cell growth, clonability, invasiveness and migratory properties. Importantly, miR-708 reexpression leads to dramatic induction of apoptosis in A498 cells suggesting that restoration of miR-708 expression in A498 cells suppressed tumorigenecity in vitro by primarily affecting the apoptotic program. In vivo, intratumoral delivery of miR-708 led to a regression of tumor growth in established renal tumor xenografts. Further, analysis of putative miR-708 targets showed that miR-708 targets survivin/BIRC5, a small inhibitor of apoptosis (IAP) protein that plays a pivotal role in renal cancer progression. In conclusion, our data suggests a crucial tumor suppressive role for miR-708 in RCC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3981. doi:10.1158/1538-7445.AM2011-3981
Abstract 3986: MicroRNA-155 regulates angiogenesis by targeting Von Hippel-Lindau (VHL) tumor suppressor
Authors: Kong William , He Lili , Tan Lei , Guo Jianping , Coppola Domenico , Coppola Marc , Cheng Jin Q.
Published: June 2012

Expression of microRNA-155 (miR-155) is frequently up-regulated in various types of human malignancy, including different forms of B cell lymphoma and carcinoma of breast, lung, colon, head/neck, and kidney; however, its role in cancer angiogenesis remains undefined. In this study, we demonstrate the critical role of miR-155 in regulation of angiogenesis through down-regulation of VHL; in addition we show elevated miR-155 levels in breast cancer correlates to high grade and late stage tumor as well as metastasis and poor overall survival. Stable ectopic expression of miR-155 in human umbilical vein endothelial cells induces tube formation in the absence of VEGF; whereas knockdown of miR-155 inhibits tube formation in the presence of VEGF. Further, we identified VHL as a direct target of miR-155. Stable overexpression of miR-155 results in repression of VHL protein; and knockdown of miR-155 rescues VHL expression. Introduction of VHL cDNA lacking 3’ untranslated region abrogates miR-155 induced tube formation. In addition, evaluation of miR-155 expression in primary breast cancers and normal mammary tissues show miR-155 high in 67 of 154 (43.5%) patients with breast cancer as compared to normal breast tissues. Elevated miR-155 is associated with high grade (49/76, 64.5%) versus low grade (18/78, 23.1%) and late stage (37/70, 52.9%) versus early stage (30/84, 35.7%) as well as invasive (53/85, 62.4%) versus non-invasive (14/69, 20.3%) breast carcinoma. Interestingly, miR-155 is also frequently overexpressed in lymph node-positive tumor (i.e., ≥ 10; 20/32, 62.5%) than node-negative (i.e., < 10; 47/122, 38.2%). Furthermore, patients whose tumors express high levels of miR-155 have shorter overall survival than those of tumors with low levels of miR-155. Our findings indicate that miR-155 plays an important role in tumor angiogenesis by targeting VHL and could be a prognostic marker and a critical therapeutic target in breast cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3986. doi:10.1158/1538-7445.AM2011-3986
Abstract 40: Similarity-based exploration of genomic profiles in glioblastoma multiforme samples
Authors: Burton Julien , Petit Joachim , Fitzhugh Will , Berens Michael , Kiefer Jeffrey , Meurice Nathalie
Published: June 2012

The main goal of this study is to deploy similarity-driven methodologies to explore data in public repositories such as The Cancer Genome Atlas (TCGA).

One of the research goals of the In Silico Research Center of Excellence at TGen and 5am Solutions is to explore the differences and similarities between genomic profiles of glioblastoma xenografts, glioblastoma patient, and non-tumor samples and use that information to select a diverse but representative population of xenografts for drug-treatment experiments. The first step consists in designing similarity-driven methodologies to describe the relations in genomic datasets publicly available such as The Cancer Genome Atlas (TCGA). This contribution presents a workflow through which the similarity relationships amongst gene expression profiles from TCGA GBM and non-tumor samples are explored. The method consists in (1) representing the data as feature vectors, (2) calculating the pair-wise similarity between the objects based on the chosen representation and a similarity metric (e.g., euclidean distance), (3) projecting the obtained similarity matrix in the 3D space of its three first principal components, calculated by Principal Component Analysis (PCA).

The 3D similarity spaces obtained lead to several interesting interpretations: the different phenotypes (GBM, non-tumor, xenografts) were accurately depicted and reduced pools of genes (gene sets) could be used as sufficient description (Gene set enrichment analysis, caBIO gene sets) to conserve the initial representation.

These observations allowed us to validate the exploratory power of the method and to use it in further analysis such as the assessment of the similarity between xenografts and GBM samples to select appropriate treatments on a genomic likeness basis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 40. doi:10.1158/1538-7445.AM2011-40
Abstract 400: Modulation of the metastatic microenvironment by soluble factors released by lung adenocarcinoma cells
Authors: Carlini María J. , Vazquez Paula , Diament Miriam , Salatino Mariana , Rabinovich Gabriel A. , Bal de Kier Joffe Elisa D. , Puricelli Lydia I.
Published: June 2012

Soluble factors from primary tumors can modify target organs for metastasis through mobilization of bone marrow derived cells (BMDCs), which are recruited to tumors and to metastatic target organs and facilitate tumor growth and metastasis. Here we aimed to study early cellular and molecular events occurring in the lung, the metastatic target organ of the murine lung adenocarcinoma cell line LP07.

We assessed by flow cytometry the numbers of BMDC positive for VEGFR1, SCF, CD34 or CXCR4 and the numbers of myeloid suppressor cells (CD11b+/Gr1+) and regulatory T cells (CD4+/CD25+/FOXP3+) in single cell lung suspensions obtained from 15-day tumor-bearing and control mice. Control and tumor-conditioned lungs of inoculated mice showed comparable amounts of these cell populations. To assess whether the primary tumor stimulates subsequent formation of macroscopic metastasis, mice bearing an intraperitoneal millipore chamber -that allows the diffusion of soluble molecules but not cell extravasation- loaded with LP07 cells or medium, were challenged with a LP07 intravenous inoculum at day 15. The presence of LP07 loaded chambers decreased the number of lung metastases three weeks after the inoculum compared to control mice (p≪0.05). In a different approach, mice were daily injected for 15 days with LP07 conditioned medium or control medium, and then challenged with a LP07 intravenous inoculum. When evaluated at day 21 post LP07 cell inoculation, the number of metastatic lung nodules was significantly lower (p≪0.05) in the group treated with LP07 conditioned medium. Besides, when we assessed matrix metalloproteinase (MMP) activity in lung homogenates from 15 day-tumor bearing and control mice, we found a significant increase in MMP-9 activity (p≪0.05) as assessed by semi-quantitative zymography in lungs from tumor-bearing mice.In conclusion, in the LP07 lung adenocarcinoma model, tumor cells secrete soluble factors that induce certain changes in the metastatic target organ, as the increase of MMP-9 activity. Moreover, in this experimental metastatic approach, a decrease in metastasis development was observed; the mechanisms underlying this phenomenon deserve further investigation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 400. doi:10.1158/1538-7445.AM2011-400
Abstract 4001: Lin28/miR-let-7c axis controls the growth and tumorigenicity of prostate cancer cells
Authors: Nadiminty Nagalakshmi , Tummala Ramakumar , Chun Jae Yeon , Lou Wei , Shi XuBao , deVere White Ralph , Gao Allen C.
Published: June 2012

Introduction: MicroRNAs (miRNA) are small ∼22 nt non-coding RNAs that regulate gene expression by binding to and inducing degradation of target mRNAs. Deregulated expression of several miRNAs has been found in prostate cancer cells. Let-7 is an evolutionarily conserved family of miRNAs that have been shown to regulate expression of several oncogenes like HMGA2, RAS and Myc. Expression of members of the let-7 family has been shown to be downregulated in many human cancers including lung, breast, ovarian and prostate. In this study, we examined the relative expression levels of let-7c and its master regulator, Lin28 in prostate cancer cells and clinical specimens. We also examined the role of the let-7/Lin28 axis in controlling proliferation in prostate cancer cells.

Methods: Expression levels of Let-7c and Lin28 in prostate cancer cells and clinical specimens were measured by real-time qRT-PCR, Northern and Western blotting. Prostate cancer cell lines with stable expression of let-7c or Lin28 were generated and their growth characteristics, clonogenic ability and colony forming abilities in soft agar were examined. Expression of let-7c was downregulated in LNCaP cells using antisense oligonucleotides and effects on growth were examined. Lentiviruses containing let-7c were injected into tumors generated by implantation of prostate cancer cells in nude mice and tumor volumes were measured.

Results: Expression levels of let-7c were found to be downregulated in castration-resistant prostate cancer cells and clinical specimens. These levels were found to be inversely correlated to expression levels of Lin28. Overexpression of let-7c reduced prostate cancer cell growth, clonogenic ability and ability to form colonies in soft agar, while downregulation of let-7c resulted in increased cell growth. Conversely, overexpression of Lin28 enhanced prostate cancer cell growth and clonogenic ability. In addition, intratumoral injection of lentiviruses containing let-7c reduced tumor volumes significantly in vivo in nude mice compared to control viruses.

Conclusions: Levels of miR-let-7c are reduced in CRPC compared to androgen-dependent prostate cancer. Levels of Lin28, which regulates processing of let-7c into its mature form, are elevated in CRPC. Overexpression of let-7c reduces prostate cancer cell growth and tumorigenic ability. These results suggest that miR-let-7c is a tumor suppressor and may be developed as a therapeutic agent against CRPC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4001. doi:10.1158/1538-7445.AM2011-4001
Abstract 4007: Defining the role of ERG-mediated repression of HPGD in prostate tumorigenesis
Authors: Ahmed Mohamed , Tan Shyh-Han , Sun Chen , Shaheduzzaman Syed , Hu Ying , Petrovics Gyorgy , Chen Yongmei , Li Hua , Sesterhenn Isabell , Sreenath Taduru , McLeod David G. , Dobi Albert , Srivastava Shiv
Published: June 2012

Activation of the ETS Related Gene (ERG) was originally identified in subsets of Ewing sarcomas, myeloid leukemias and, recently, in the majority of prostate cancers (CaP). Emerging studies in experimental models underscore functions of ERG in prostate tumorigenesis. However, biological functions of ERG in CaP remains to be better understood. Evaluation of ERG downstream targets identified 15-hydroxyprostaglandin dehydrogenase gene (HPGD) in response to ERG knockdown. Several recent studies have indicated that HPGD, the main catabolizing enzyme of prostaglandins and lipoxins and a tumor suppressor, is down-regulated in a majority of lung, colon, breast, and bladder cancers. However, the regulation of HPGD within the biological context of ERG expressing prostate tumors remains to be defined. The objective of this study was to evaluate the effects of ERG on the prostaglandin signaling pathway in prostate cancer.

Correlation between HPGD and ERG expression was evaluated at the mRNA and protein levels in prostate cancer specimens and cell lines by Western blot, QRT-PCR, and immunofluorescence assays. Small interference RNA against human ERG and HPGD were used to knock-down their respective expressions. Functional consequences of ERG and HPGD knockdown in VCaP cells harboring TMPRSS2-ERG fusions were assessed by ChIP and BrdU cell proliferation assays.

The experiments showed that loss of ERG expression leads to a robust overexpression of HPGD in prostate cancer cells. Furthermore, we observed altered PGE2 production, decreased expression of prostaglandin E2 receptor 4 (EP4), and inhibition of prostaglandin E2 induced cell growth. Chromatin immunoprecipitation experiments revealed direct binding of ERG protein to the HPGD core promoter. Comparison of HPGD expression in TMPRSS2-ERG positive and negative prostate tumors indicated a trend towards decreased HPGD expression.

In conclusion ERG activation, as a consequence of TMPRSS2-ERG fusions, may influence the components of the prostaglandin signaling pathway in prostate tumorigenesis disrupting the tumor suppressor functions of HPGD. These findings suggests for a new biological role of ERG in CaP that may be further evaluated as a target for prevention, as well as early therapeutic intervention in CaP.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4007. doi:10.1158/1538-7445.AM2011-4007
Abstract 401: Inducible nitric oxide synthase suppresses the expression of CXCL10 and hence leads to the poor outcome of Stage III malignant melanoma
Authors: Tanese Keiji , Ekmekcioglu Suhendan , Grimm Elizabeth
Published: June 2012

Melanoma is the deadliest form of skin cancer and exhibits extremely aggressive growth characteristics. Accumulating evidence suggests that melanoma is heterogeneous in response to therapies as well as etiology, survival with advanced disease, and tumor mutational status. Our previous studies showed that the expression of inducible nitric-oxide synthase (iNOS) in melanoma tumor cells strongly correlate with poor patient survival. We are hypothesizing that iNOS is a key molecule in melanoma signature comprising an inflammatory microenviroment of poor outcome. To gain further insight into the nature of the melanoma inflammatory microenvironment, PCR array related to inflammatory and autoimmunity gene was done on a series of Stage 3 melanoma lymph node metastases samples to compare the gene expression level directly between iNOS-positive and -negative tumor samples. As a result, we found the significant correlation between iNOS expression and suppression of CXC Chemokine ligand 10 (CXCL10) in mRNA and protein levels. In the set of 16 cases of Stage3 melanoma samples, high CXCL10 expressing group showed the favorable prognosis compared to low CXCL10 expressing group. In the further in vitro analysis, we found that nitric oxide (NO) provided by S-nitroso-N-acetyl-l,l-penicillamine suppresses the expression of CXCL10 in iNOS negative and CXCL10 positive melanoma cell. Quenching the NO with NO scavenger, 2-(4-Carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide in iNOS positive and CXCL10 negative cell lines induces the expression of CXCL10. CXCL10 is reported to play the role in the recruitment of cytotoxic immune cells such as CD8+ T cells, and NK cells into the tumor microenvironment. CXCL10 also has a function of antagonizing the activities of angiogenic factors such as bFGF and IL-8 and it is considered as an anti-tumorigenic protein. Our study suggests that production of NO by iNOS inhibits the expression of CXCL10 in melanoma and comprises the pro-tumorigenic tumor microenvironment. Inhibition of NO may have a possibility to render the tumor microenvironment to anti-tumorigenic status. Therefore, iNOS will be a good target in the treatment of melanoma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 401. doi:10.1158/1538-7445.AM2011-401
Abstract 4011: Evidence supporting a role of c-Myb in pancreatic cancer
Authors: Singh Seema , Srivastava Sanjeev K. , Bhardwaj Arun , Owen Laurie B. , Grizzle William E. , Singh Ajay P.
Published: June 2012

The clinical outcome from pancreatic cancer has not improved over the years. This is, in part, due to not well understood disease mechanisms and consequently there is little progress made in developing intervention therapy. Many genetic alterations have been characterized in pancreatic cancer, of which some have been shown to be functionally relevant. In an earlier study, c-Myb was identified as a candidate oncogene in pancreatic cancer with gene amplification in a subset and overexpression in majority of pancreatic cancer tissues and cell lines. The role of c-Myb in pancreatic cancer, however, has not been defined so far. c-Myb is a cellular progenitor of v-Myb oncogenes, which encodes for a transcription factor and confers its oncogenic activity by regulating the expression of several target genes. To examine the functional role of c-Myb in pancreatic cancer, we silenced its expression in two pancreatic cancer cell lines (Panc1 and MiaPaCa) by stable transfection of a c-Myb-targeted short-hairpin RNA (shRNA)-expression plasmid. Silencing of c-Myb expression resulted in diminished growth and clonogenicity of pancreatic cancer cells. c-Myb knockdown pancreatic cancer cells were arrested at G1/S boundary of cell cycle, and exhibited enhanced apoptosis. Furthermore, we observed decreased migration and invasion in c-Myb silenced pancreatic cancer cells as compared to the control cells. Immunoblot analysis demonstrated gain of epithelial- and loss of mesenchymal- markers in c-Myb knockdown pancreatic cancer cells, thus indicating a reversal of epithelial to mesenchymal transition (EMT). We also observed noticeable changes in cell morphology and actin-organization upon silencing of c-Myb expression that were consistent with loss of mesenchymal features. Together, these findings provide first experimental evidence for a functional role of c-Myb in pancreatic cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4011. doi:10.1158/1538-7445.AM2011-4011
Abstract 4013: Transcriptional regulation of EGR1 by EGF and the ERK signaling pathway in prostate cancer
Authors: Gregg Jennifer L. , Fraizer Gail C.
Published: June 2012

The early growth response gene 1, EGR1, is an important transcriptional regulator and acts as the convergent point between a variety of extracellular stimuli and activation of target genes resulting in diverse responses such as cell growth, proliferation, and apoptosis. Unlike other tumor types, in prostate tumor tissues EGR1 expression is elevated relative to normal tissues. However, the mechanism(s) of regulation of EGR1 in prostate tumor cells are unknown. As EGR1 expression and epidermal growth factor (EGF) signaling are frequently upregulated in prostate tumors, we tested the hypothesis that EGF induces EGR1 expression in prostate cancer cells. Using real-time PCR to quantify EGR1 transcripts, EGF induced EGR1 expression levels in a dose and time-dependent manner; and kinase inhibitors, PD98059 and wortmannin, abrogated the EGF-mediated EGR1 response. Analysis of the EGR1 promoter using reporter constructs identified an EGF-responsive region in the proximal promoter containing three potential serum response element (SRE) sites. In vivo chromatin immunoprecipitation assays demonstrated that EGF enhanced Elk-1 binding at the SRE sites of the EGR1 promoter in PC3 cells, and Elk-1 also bound in the absence of stimulus. Overexpression of Elk-1 enhanced activation of the EGF-responsive region indicating that Elk-1 is sufficient to activate EGR1 in PC3 cells. Similarly, a dominant-negative Elk-1 suppressed EGR1 promoter activity indicating that Elk-1 is necessary for EGF-induced EGR1 transcription in both PC3 and LNCaP cells. Taken together, these results demonstrate that EGR1 expression in prostate cancer cells is mediated through an EGF-ERK-Elk-1 signaling cascade. Since elevated EGF and EGF receptor are associated with prostate cancer progression, these results may explain elevated EGR1 in high-grade prostate tumors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4013. doi:10.1158/1538-7445.AM2011-4013
Abstract 4018: The role of FLI1 in breast cancer development and progression
Authors: Scheiber Melissa Nicole , Watson Patricia M. , Findlay Victoria J. , Rumboldt Tihana , Watson Dennis K.
Published: June 2012

Breast cancer is the second most common cancer-related death among women in the US. The majority of the breast cancer-related deaths are due to tumor progression. A multitude of changes in gene expression are required for the cancer cell to acquire the ability to invade and migrate. The transcriptional activation or repression of these cancer-associated genes is not clearly understood, however many ETS family members have been considered good candidates. Friend leukemia virus integration 1 (FLI1) is an ETS protein that is aberrantly expressed in retrovirus-induced hematological tumors, and is found to be rearranged in Ewing's sarcoma and related primitive neuroectodermal tumors characterized by a t(11;22)(q24;q12) translocation. Limited attention has been directed towards elucidating the potential role of FLI1 in epithelial-derived cancers, including breast cancer. Our preliminary immunohistochemical analyses show that FLI1 protein is decreased in human invasive breast tumors compared to normal breast tissue. A decrease of FLI1 mRNA and protein was also demonstrated in breast cell cancer cell lines through Real Time RT-PCR and western blot, respectively. We used adenovirus to examine the effects of FLI1 expression in two invasive breast cancer cell lines (MDA-MB-231 and MDA-MB-157). Re-expression of FLI1 in both MDA-MB-231 and MDA-MB-157 inhibited cell growth, mainly due to a decrease in cellular proliferation. FLI1 expression also inhibited the motility and invasiveness of breast cancer cell lines, determined by the use of Transwell inserts coated with fibronectin or Matrigel, respectively. We hypothesize that the loss of FLI1 is a critical step for breast cancer progression. Loss-of-function studies using shRNA are being performed to complement the above gain-of-function studies. Future studies will investigate potential downstream targets of FLI1. Inhibiting the reduction of FLI1 or regulating its downstream targets may be to be unique targets of breast cancer therapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4018. doi:10.1158/1538-7445.AM2011-4018
Abstract 4023: ARID1A is a candidate tumor suppressor gene in breast cancer
Authors: Chabot Catherine , Mamo Aline , Cavallone Luca , Tuzmen Sukru , Hassan Saima , Edgren Henrik , Ferrario Cristiano , Aleynikova Olga , Przybytkowska Ewa , Malcolm Kristin , Kallioniemi Olli , Tonin Patricia , Mousses Spyro , Basik Mark
Published: June 2012

Tumor suppressor genes (TSGs) have been classically defined as genes whose loss of function in tumor cells contributes to the formation and/or maintenance of the tumor phenotype. Typically but not always, tumors neutralize both alleles of TSGs by deleting one copy and mutating the other. One molecular strategy to discover potential tumor suppressor gene candidates involves the “re-expression” of RNA transcripts containing nonsense mutations by inhibition of the nonsense-mediated RNA decay (NMD) process. Combining NMD inhibition with array CGH has lead to the genome-wide identification of genes with biallelic inactivation (involving nonsense mutations on one allele and loss of the second allele) in prostate cancer cell lines and identified EphB2 as a novel candidate TSG in prostate cancer. Using such a strategy in 5 breast cancer cell lines, we identified ARID1A as a NMD target in the T47D breast cancer cell line. ARID1A encodes a human homologue of yeast SWI1, which contains a DNA-binding motif (AT-rich interactive domain, ARID) and is an integral member of the hSWI/SNF complex, an ATP-dependent chromatin-remodeling multiple-subunit enzyme. Mutations in the ARID1A gene were recently reported to be present in 50% of clear cell tumors of the ovary. We found the ARID1A gene contains a nonsense mutation in exon 9, which introduces a premature stop codon, changing Q944 to a stop codon in the T47D breast cancer cell line. Although we did not find any somatic mutations in breast tumors, we show that low ARID1A RNA expression or low ARID1A nuclear protein expression is associated with more aggressive breast cancer phenotypes in 2 independent cohorts of over 200 breast cancers each. We also found that low or absent ARID1A nuclear expression becomes more prevalent during the later stages of breast tumor progression. Finally, we found that ARID1A re-expression in the breast cancer cell line in which it is mutated results in significant inhibition of colony formation in soft agar. These results suggest that the ARID1A gene may be a candidate tumor suppressor gene in breast cancer, and that it warrants further investigation as potential diagnostic and therapeutic marker in breast cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4023. doi:10.1158/1538-7445.AM2011-4023
Abstract 4024: ING4 tumor suppressor binds to estrogen receptor-complex and modulates estrogen-dependent cell growth and gene expression in breast cancer
Authors: Dempsey Katherine J. , Whitsett Timothy G. , Kim Suwon
Published: June 2012

The tumor suppressor ING4 (Inhibitor of Growth family member 4) has been shown to play a role in diverse cancer-related cellular processes, including gene regulation, apoptosis, cell migration, contact inhibition, and angiogenesis. Deletion or reduced expression of ING4 has been shown in a number of human malignancies, including breast cancer. We found ING4 to be deleted in 15% of estrogen receptor-positive (ER+) breast cancers, implicating a role for ING4 as a tumor suppressor in estrogen-driven breast cancer. In addition, we showed that over-expression of ING4 abrogated, whereas ING4 knock-down enhanced, estrogen-dependent cell growth of MCF7 ER+ breast cancer cells, indicating a suppressive function of ING4 in estrogen-dependent cell growth. The molecular mechanisms of ING4 in ER+ breast cancers have not yet been elucidated.

Using a bacterial two-hybrid screen, we identified CCAR1 (Cell-Cycle and Apoptosis Regulatory Protein 1) as an ING4 binding protein. Subsequently, we validated interactions between ING4 and CCAR1 in 293T and MCF7 cells using co-immunoprecipitation assays. CCAR1 had previously been shown to be a co-activator of the estrogen receptor (ER) complex that is required for estrogen-dependent cell growth and gene transcription in ER+ breast cancer cells (Kim JH, Yang CK, Heo K, Roeder RG, An W, and Stallcup MR, 2008). Taken together, these results suggested that ING4 may interact with the ER-complex and implicated a role for ING4 in the ER-mediated cellular processes. Here we show that ING4 co-immunoprecipitates with estrogen receptor-alpha (ERα) and the co-activator AIB1 in MCF7 and T47D ER+ breast cancer cells, demonstrating ER:ING4 interactions in cells. Treatment with 17β-estradiol (E2) reduced ING4:ER interactions. These results suggested that ING4 may not be a co-factor in the estrogen-bound active ER-complex, supporting our hypothesis that ING4 plays a role in the modulation of the ER-complex. Strikingly, tamoxifen treatment greatly enhanced ING4 association with ERα, suggesting that tamoxifen stabilizes ER:ING4 interactions and/or ING4 has a greater binding affinity to the tamoxifen-bound ER-complex. It is possible that ING4 plays a role in the recruitment of co-repressors to the tamoxifen-bound ER-complex. These results implicate a role for ING4 in tamoxifen response. We conclude that ING4 may function as a tumor suppressor in ER+ breast cancers by binding to the ER-complex and modulating estrogen-dependent cellular processes including cell proliferation and gene transcription.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4024. doi:10.1158/1538-7445.AM2011-4024
Abstract 4037: Loss of Par3 induces an epithelial to metastatic-epithelial transition during ErbB2 induced mammary tumor progression
Authors: Xue Bin , Krishnamurthy Kannan , Muthuswamy Senthil K.
Published: June 2012

The Partitioning defective (Par) proteins are part of an evolutionarily conserved complex that is known to regulate asymmetric cell division, cell junction biogenesis and epithelial morphogenesis, but the role they play in cancer is not well understood. Here we demonstrate that loss of Partitioning defective 3 (Par3) cooperates with activation of the receptor tyrosine kinase ErbB2 to induce migration and invasion of normal and tumor-derived human mammary epithelial cells. Surprisingly, the acquisition of invasive ability was not associated with an overt mesenchymal transition as determined by a lack of expression of mesenchymal markers and retention of an epithelial morphology. We demonstrate that loss of Par3 induces aberrant activation of the small GTP binding protein Rac, loss of cortical actin and a decrease in cell-cell adhesion. Par3 is known to interact with and inhibit the Rac exchange factor Tiam1, consistently, ectopic expression of Tiam1 phenocopied Par3 loss and was sufficient to cooperate with ErbB2 to induce invasion and a decrease in intercellular adhesion. Inhibition of Tiam1-induced Rac activation restores cortical actin network and cell-cell junctions and blocks ErbB2-induced migration and invasion. Expression of Par3 was downregulated in both human breast cancer and in the metastasis resulting from ErbB2-expressing primary mouse mammary tumors. Forced downregulation of Par3 in ErbB2-tumor-derived primary epithelial cells promoted metastasis in vivo demonstrating that loss of Par3 is sufficient to initiate metastatic progression of ErbB2-induced mammary tumors. Thus, loss of Par3 induces metastatic properties to epithelial cells while expression of Par3 is required to maintain a non-metastatic epithelial state of tumor cells. Our observations on metastatic epithelia identify a novel mechanism by which tumor cells metastasize while retaining epithelial characteristics.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4037. doi:10.1158/1538-7445.AM2011-4037