bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2945: Antitumor activities of 2-fluorofucose, an orally active agent that inhibits cell-surface fucosylation
Authors: Okeley Nicole , Zhang Amy , Alley Stephen , Anderson Martha , Law Che-Leung , Senter Peter
Published: August 2012

Fucose is a component of many carbohydrates that are found on the outer membranes of cancer cells. There is evidence that loss of this sugar from cell-surface glycoproteins can change cancer cell behavior, including growth and metastasis. We have previously demonstrated that 2-fluorofucose (SGD-2083) blocks the fucosylation of antibodies in vitro and in vivo due to the depletion of GDP-activated fucose inside cells. These findings provide the basis for evaluating the antitumor activities of SGD-2083, since alterations of the fucose content on cell surfaces could potentially impact tumor growth and adhesion. To explore this, SGD-2083 was given orally to mice with carcinoma and hematologic tumor xenografts. Significant antitumor activities were obtained in prostate, renal cell and colorectal carcinomas, but not in the two hematologic cancer models tested. The doses used to achieve efficacy were well-tolerated. FACS analysis was used to detect alterations in tumor cell surface fucosylation in animals that responded to treatment with SGD-2083. Signal reduction was observed on E-selectin ligand and several other cell surface fucose linkages, while little or no response to the treatment was observed in the fucosylation of cell surface P-selectin ligand. These results show that oral administration of SGD-2083 leads to the alteration of tumor cell surface fucosylation in a well-defined manner, and this may account for the observed activities of this novel antitumor agent.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2945. doi:1538-7445.AM2012-2945
Abstract 2946: Post-transcriptional regulators of microRNA biogenesis regulate pathogenesis of cancer
Authors: Chung Wei-Jen , Sumazin Pavel , Yang Xuerui , Bansal Mukesh , Califano Andrea
Published: August 2012

MicroRNAs (miRs) have emerged as key regulators of both normal and pathologic phenotypes, including cancer. Fine grained regulation of their biogenesis, however, is still poorly understood and only a few of their key regulators have been characterized. In order to understand the extent and specificity of miR-biogenesis control, as well as the role of miR-biogenesis regulators in tumorigenesis and cancer progression, we set out to identify these regulators and profile their targets. We developed a genome-wide computational screening method that leverages miR and gene expression profiles in hundreds of samples to identify potential biogenesis regulators in glioma and ovarian cancer. In total, miRage predicted thirty miR-biogenesis regulators that are common to glioma and ovarian cancer tumors, and hundreds of glioma-specific and ovarian-cancer-specific regulators. Predicted regulators include known biogenesis regulators DGCR8, HNRNPA1, DDX5, LIN28 and SMAD family proteins. We validated selected regulators that are predicted to regulate miRs in both cancers and are differentially expressed across glioma prognosis. Differential expression of (1) mature miRs, (2) their host genes, (3) co-transcribed miRs, (4) miR precursors, and (5) pri-miRs were measured upon ectopic expression or RNAi-mediated silencing of the predicted regulators in a glioma cell line. DDX10 was predicted to up-regulate miR-218 biogenesis, and we showed that its ectopic expression up-regulates miR-218 at the pri-miRNA stage; up-regulation of DDX10 may account for miR-218 over-expression in poor-prognosis tumors. High-throughput screening by nanostring nCounter and fluidigm systems suggest that DDX10 regulation is broader effect than regulation by the known biogenesis regulator, DDX17. In total, we report on nearly a dozen validated miR-biogenesis regulators that were predicted by our computational screens. Our results suggest that miR biogenesis is a complex, context specific, and finely-regulated process, and that miR biogenesis regulators may influence tumor initiation and progression by altering the expression of specific tumor-suppressor and oncomirs or by modifying large miR programs.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2946. doi:1538-7445.AM2012-2946
Abstract 2949: miR-16 is an in vivo suppressor of gastrointestinal tumorigenesis
Authors: Moore Ashleigh E. , Young Lisa E. , Weiler Jan , Meisner-Kober Nicole , Dixon Dan A.
Published: August 2012

Commonly observed in colorectal cancer (CRC) is elevated expression of the prostaglandin synthase cyclooxygenase-2 (COX-2). In normal intestinal epithelium, the COX-2 mRNA is normally targeted for rapid decay through RNA elements present within its 3′-untranslated region (3′UTR), whereas in tumors rapid mRNA decay is compromised. To understand the mechanisms controlling COX-2 mRNA fate, we show that the COX-2 3′UTR can mediate mRNA degradation through microRNA-mediated regulation. MicroRNAs (miRNAs) are small non-coding RNAs that bind within the 3′UTR of target mRNAs and function as post-transcriptional regulators of gene expression. MiR-16 was identified to bind the COX-2 3′UTR and inhibit COX-2 expression by promoting rapid mRNA decay. Given the importance of miR-16 in cancer development, we examined miR-16 expression in CRC tumor specimens and cancer cells and observed a 2-fold decrease in miR-16 levels. Additionally, expression of miR-16 in cancer cells attenuated COX-2 expression and prostaglandin synthesis. The in vivo role of miR-16 in the initiation and development of colorectal cancer was examined using ApcMin/+ mice, a mouse model of intestinal neoplasia. To accomplish this, endogenous miR-16 was inhibited in the GI tract using an anti-miR oligonucleotide (AMO) against miR-16 containing 2′-O-(2-Methoxyethyl) modification with unmodified PO backbone. 50 mg/kg of AMO-16 or control AMO containing 4 nucleotide-mismatch of the AMO miR-16 sequence were administered by oral gavage to 8 week old ApcMin/+ and C57Bl/6 control mice twice a week over a 3-week period. Specific inhibition of miR-16 in intestinal tissue was observed. Over the treatment course, control mice displayed normal growth characteristics. Gross and histological analysis did not reveal any morphological changes in the GI tract of AMO-16-treated C57Bl/6 mice. In contrast, a significant 2-fold increase in small intestinal tumor burden was observed in ApcMin/+ mice treated with AMO-16 compared to control AMO (55.7 +/− 5.0 vs. 99.1 +/− 7.9, P = 0.0001). Gene expression analysis showed increased COX-2 and several miR-16 target cell cycle regulatory genes including cyclin D1, cyclin D3, cyclin E1, and CDK6 in AMO-16-treated small intestinal tissue from ApcMin/+ mice compared with AMO control treated mice, with the greatest level of altered expression observed in the proximal portion of the small intestine. These results identify miR-16 as a central post-transcriptional regulator of COX-2 along with other transcripts associated with promoting cancer cell proliferation, and reveal miR-16 to have tumor-suppressor properties in GI tumorigenesis downstream of a tumor-initiating event.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2949. doi:1538-7445.AM2012-2949
Abstract 295: IDO drives tumor-promoting, pathogenic inflammation in lung
Authors: Smith Courtney , Chang Mee-Young , Flick Hollie , DuHadaway James , Mandik-Nayak Laura , Laury-Kleintop Lisa , Parker Katherine , Beury Daniel , Ostrand-Rosenberg Suzanne , Prendergast George C. , Muller Alexander J.
Published: August 2012

First identified as a mediator of acquired immune tolerance of the ‘foreign’ fetus from maternal immunity, the tryptophan-catabolizing enzyme IDO (indoleamine 2,3-dioxygenase) has since been implicated in tumor escape from the host immune system. Insight into the intricate role of IDO in the classical DMBA/TPA skin carcinogenesis model suggested that inflammatory tumor environments can induce IDO production resulting in de novo tumor development. In the genetically deficient model of IDO, mice show resistance to tumor formation. This provided a basis for our current studies exploring the importance of IDO in the microenvironment of the lung. To this end, we have investigated both primary tumor formation and metastatic disease in the lungs of IDO-deficient mice using the KRAS-induced lung adenocarcinoma and the metastatic 4T1 breast cancer models. Elevation of the inflammatory cytokine IL6 was associated with tumor outgrowth in the lungs in both models but was greatly attenuated with the loss of IDO, consistent with the in vitro demonstration that IDO activity markedly potentiates IL6 production. MDSCs (myeloid derived suppressor cells) exhibited reduced T cell suppressive activity when isolated from tumor-bearing, IDO-deficient animals that could be rescued by ectopic production of IL6 in the tumor. IL6 production could likewise reverse the pulmonary metastasis resistance exhibited by IDO-deficient mice. Interestingly, while there is a clear role of the immune system in lung tumor and metastatic outgrowth, IDO-deficient mice appear to have reduced vascularization in the lung which may partly contribute to reduced tumor formation. Together, these findings genetically validate IDO as a therapeutic target in the settings of pulmonary cancer and metastasis and establish the importance of IDO as a driver of IL6 production and MDSC function. Furthermore, the correlation of IDO to angiogenesis may be a new insight into the role of this enzyme in cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 295. doi:1538-7445.AM2012-295
Abstract 2950: miR-34 prevents in vivo lung tumor initiation and progression in the therapeutically resistant Kras;p53 mouse model
Authors: Kasinski Andrea L. , Slack Frank J.
Published: August 2012

Lung cancer represents the leading cause of cancers deaths in men and women worldwide, and current therapies fail to treat this disease in the overwhelming majority of cases. The RAS and p53 pathways are two of the most frequently genetically modified pathways in lung cancers. Alterations in both result in loss of responsiveness to current therapies leading to decreased overall patient survival. Because the microRNA, mir-34 is a downstream transcriptional target of p53, which is reduced in its expression in p53 null tumors, we hypothesized that targeting Kras;p53 tumors with miR-34 would represent a novel yet powerful therapeutic to suppress lung tumorigenesis. To this end we have made use of the therapeutically resistant KrasLSL-G12D/+;p53LSL-R172H/+ mouse model of lung cancer. In this work we characterized the tumor progression in these mice following transgene activation specifically in the lung through intratracheal administration of adenoviral particles expressing cre recombinase. We note that adenocarcinomas are evident as early as 10 weeks following cre-recombination with severe lung inflammation presenting at 22 weeks. Epithelial cells from these tumors were harvested and cultured in vitro where they remain propagating, currently at passage 45. All three lines generated support growth in soft agar assays and are invasive based on transwell migration assays. Because of the pro-apoptotic effects of miR-34, we transduced the cells with miR-34-expressing lentivirus. Transduced cells responded with reduced proliferation and decreased migration. Based on these promising results we began two series of in vivo experiments. We first assessed the contribution of miR-34 to prevent tumor formation in KrasLSL-G12D/+;p53LSL-R172H/+ mice. Animals that were treated with miR-34 at the same time as cre-induced recombination of transgenes show little to no evidence of tumorigenesis at 19 weeks, while control animals had multiple nodules that represented ∼8% of the total lung area. The second series of in vivo experiments evaluated the ability of miR-34 to act as a treatment in pre-formed tumors. While miR-34 was unable to reduce the preformed tumors in these animals it was able to prevent further tumor growth. These data support the use of miR-34 as a tumor preventive mechanism and suggest that miR-34 may be useful in sensitizing tumors to other conventional therapeutics.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2950. doi:1538-7445.AM2012-2950
Abstract 2959: p53 as a guardian of genomic junk: A novel role for p53 in epigenetic silencing of retroelements
Authors: Leonova Katerina , Lipchick Brittany , Brodsky Leonid , Komarova Elena , Gudkov Andrei V.
Published: August 2012

Demethylating agents have been reported to be more toxic to p53-deficient cells than wild type (WT) cells in several models. To elucidate the mechanism underlying this phenomenon, we performed microarray-based global gene expression profiling of mouse embryo fibroblasts (MEFs) from p53-WT and p53-null mice with or without 5-aza-2′-deoxycytidine (5-aza-dC) treatment. This analysis revealed two major findings. First, all protein-coding transcripts induced by 5-aza-dC treatment in WT cells were highly expressed and irresponsive to the demethylating agent in untreated p53-deficient cells. This observation defines p53 as a major driver of DNA methylation-dependent gene silencing. Second, death of p53-null cells treated with 5-aza-dC is preceded by strong activation of transcription of interferon (IFN)-responsive genes driven by IFNα induction. Since no obvious candidates for the role of IFN-inducing factors were found among the genes represented on the microarray, we carried out high-throughput sequencing (HTS) of the entire transcriptome of p53-WT and p53-null MEFs, treated or untreated with 5-aza-dC. The HTS results revealed striking transcriptional upregulation of numerous genetic elements belonging to various classes of retrotransposons and non-coding RNAs in p53-null, but not in p53-WT cells, treated with 5-aza-dC. We named this phenomenon of massive induction of transcription of retroelements, which are normally repressed by p53, RETROSIS. Retrosis is likely to be the trigger of the observed IFN response and the mediator of toxicity in p53-null cells treated with 5-aza-dC. These findings define a novel role for p53, acting along with DNA methylation, in regulation of epigenetic silencing of the large proportion of the genome that consists of retroelements and suggest a new evolutionary role for this tumor suppressor. The impact of retrosis in tumor cells deficient in p53 and implications of this phenomenon for the tumor suppressor function of p53 will be discussed.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2959. doi:1538-7445.AM2012-2959
Abstract 2961: Reactivation of EWS-FLI1 suppressed FOXO1 expression as a novel therapeutic strategy for Ewing's sarcoma
Authors: Niedan Stephan , Kauer Max , Jug Gunhild , Walker Robert L. , Meltzer Paul S. , Kontny Udo , Kovar Heinrich
Published: August 2012

The EWS-FLI1 chimeric protein, characterizing Ewing's sarcoma (ESFT), is prototypic for an aberrant oncogenic ETS transcription factor. The mechanisms of transcriptional regulation leading to ETS-driven tumorigenesis are poorly understood. In-silico analysis of time-resolved expression data revealed enrichment of recognition motifs for forkhead box (FOX) proteins in EWS-FLI1 repressed promoters. Several FOX genes were found to be bound by EWS-FLI1 in ChIP-seq and transcriptionally affected by EWS-FLI1 knockdown. We therefore hypothesized that EWS-FLI1 exerts an important part of its repressive activity via inhibiting FOX proteins. Upon silencing of EWS-FLI1, both FOXO1 and FOXO3 proteins were strongly induced in ESFT cells consistent with this hypothesis, but only FOXO1 translocated to the nucleus. However, in the presence of EWS-FLI1, FOXO1 is excluded from the nucleus as a consequence of phosphorylation. Nuclear translocation was restored by either inhibition of CDK2, augmented by chemical inhibition of PI3K, or by mutation of CDK2 or AKT phosphorylation sites. Furthermore, ChIP experiments revealed that EWS-FLI1 directly binds the promoter of FOXO1 in vitro suggesting a multi-layered regulation of FOXO1 expression by transcriptional repression and post-translational modification. Functional restoration of nuclear FOXO1 expression in ESFT cells resulted in impaired proliferation and significantly reduced soft agar colony formation ability. A significant overlap between EWS-FLI1 repressed and FOXO1 activated genes was observed. Treatment of ESFT cell lines with Methyl-Seleninic-Acid (MSA) led to re-activation of endogenous FOXO1 in the presence of EWS-FLI1 in a dose- and time-dependent manner, and induced massive cell death, which we found to be at least partially FOXO1-dependent. Taken together, these data confirm our hypothesis that a repressive sub-signature of EWS-FLI1 regulated genes is due to suppression of FOXO1. FOXO1 re-activation by small molecules may constitute a novel therapeutic strategy in the treatment of ESFT. This study was supported by grant 22328-B09 from the Austrian Science Fund FWF.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2961. doi:1538-7445.AM2012-2961
Abstract 2963: ALK is a MYCN target gene and contributes to cell growth, migration and invasion in neuroblastoma
Authors: Hasan Md. Kamrul , Takatori Atsushi , Kishida Satoshi , Ohira Miki , Hossain Md. Shamim , Akter Jesmin , Ogura Atsushi , Nakamura Yohko , Kadomatsu Kenji , Nakagawara Akira
Published: August 2012

Neuroblastoma (NBL), the most common solid tumor of childhood, is an embryonal malignancy of the developing sympathetic nervous system. Human Anaplastic lymphoma kinase (ALK) has been identified as an oncogene mutated or amplified in NBLs. However, the role of wild-type ALK in NBL is still largely unknown. For better understanding a molecular event associated with ALK in the pathogenesis of NBL, it is necessary to clarify how ALK gene contributes to NBL progression. Previously in the analysis of NBL clinical samples, we have found that ALK expression is significantly high in MYCN amplified group. Consistent with this evidence, the developing tumors with NBL characteristics in MYCN-transgenic mice possess a high expression of ALK. In the present study, we have found that overexpression of MYCN induced ALK expression and siRNA-mediated knockdown of MYCN resulted in the downregulation of ALK expression in NBL and non-NBL cell lines. We have identified the promoter region of ALK, to which MYCN binds, in the upstream of the first exon from +30 to −350 bp and Luciferase reporter assay showed that MYCN overexpression enhanced the promoter activity of ALK. The site-specific deletion at MYCN binding site of ALK promoter region downregulated its promoter activity and chromatin immunoprecipitation (ChIP) assay indicated that MYCN can be recruited to the ALK promoter region, suggesting that ALK is directly regulated by MYCN. In general, high expression of MYCN is a well-known prognostic marker for aggressive progression and increases growth rate of NBL cells. However, the role of MYCN in enhancing cell migration and invasion has not yet been fully understood. We have further examined an effect of ALK expression in MYCN-induced cell migration. Functional assay revealed that overexpression of ALK enhanced NBL cell growth, migration as well as invasion. Moreover, these activities were suppressed by siRNA-mediated knockdown of ALK, indicating that ALK might be involved in the metastatic phenotype of NBLs. On the other hand, the forced expression of MYCN enhanced cell migration in MYCN-single copy cell line, SK-N-AS cells. Of interest, the increased migration by MYCN expression was suppressed by siRNA-mediated knockdown of ALK, suggesting that the cell migration induced by MYCN is at least partly regulated by ALK expression. Our present findings explore the fundamental understanding of ALK and help a future development of novel therapeutic tools by targeting ALK for aggressive NBLs.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2963. doi:1538-7445.AM2012-2963
Abstract 2968: TH17 cells in early pancreatic tumorigenesis
Authors: McAllister Florencia , Bailey Jennifer M. , Roeser Jeffrey , Blake Danielle T. , Wick Elizabeth C. , Sears Cynthia L. , Jaffee Elizabeth M. , Kolls Jay K. , Drake Charles G. , Pardoll Drew M. , Leach Steven D.
Published: August 2012

Activating Kras mutations have been detected in 30% of pancreatic intraepithelial neoplasias (PanIN), increasing to 100% in advanced pancreatic ductal adenocarcinoma (PDAC). Chronic pancreatitis is a risk factor for PDAC and cigarette smoking, the most important single risk factor for PDAC, has been recently associated with chronic pancreatic inflammation. The central hypothesis guiding our work is that inflammatory cells recruited to the pancreas in response to chronic injury can interact with epithelial cells harboring activated KrasG12D, affecting the progression of PanIN lesions. Further understanding of this interaction would be fundamental to generate effective chemopreventive strategies in high risk populations. To test this hypothesis, we have used the Mist1:CreERT2; LSL-KrasG12D mice in which the LSL KrasG12D allele is activated specifically in the acinar compartment of adult mice, leading to the rapid formation of PanIN with a classic “ductal” phenotype. We have established a model of chronic inflammation- induced pancreatic tumorigenesis that results in significant acceleration in the initiation and progression of PanIN lesions at 4 weeks after the activation of Kras. We have found that TH17 cells, a subtype of CD4+ T-helper cells known to play an active role in other models of inflammation- induced tumorigenesis, are rapidly recruited to the pancreas after Kras activation and are further increased in the presence of concomitant chronic pancreatic inflammation induced by cerulein injections. The differentiation of CD4+T cells into TH17 requires IL-6 and TGF-B, and both factors are increased in the pancreatic tumor microenvironment. Finally, Stat3, a key transcription factor that determines the differentiation of Th17 lineage, is activated in cells infiltrating early PanIN lesions. We are currently evaluating both genetic ablation of TH17 cells and neutralizing antibodies against IL-17 as novel therapeutics strategies in murine PanIN.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2968. doi:1538-7445.AM2012-2968
Abstract 2976: KSHV-initiated Notch activation leads to membrane-type-1 matrix metalloproteinase-dependent lymphatic endothelial-to-mesenchymal transition
Authors: Pekkonen Pirita , Cheng Fang , Sugiyama Nami , Henderson Stephen , Rantanen Ville , Aavikko Mervi , Hautaniemi Sampsa , Aaltonen Lauri , Boshoff Chris , Alitalo Kari , Lehti Kaisa , Ojala Päivi M.
Published: August 2012

Kaposi sarcoma (KS), an angioproliferative disease associated with Kaposi sarcoma herpesvirus (KSHV) infection, harbors a diversity of cell types ranging from endothelial to mesenchymal cells of unclear origin. Using a novel three-dimensional (3D) cell model, we have demonstrated that KSHV induces transcriptional reprogramming of primary lymphatic endothelial cells (LEC) to mesenchymal cells via endothelial-to-mesenchymal transition (EndMT). As EndMT induction has been described in response to activation of the TGF-beta or Notch pathways, inhibitor studies were used to decipher their roles in our 3D system. Inhibition of the Notch pathway dramatically attenuated the EndMT in KSHV infected LECs (K-LECs) in 3D whereas inhibition or activation of the TGF-β pathway did not have any effect. Two viral gene products, vFLIP and vGPCR, were found to trigger Notch signaling and lead to the KSHV-induced EndMT. As Notch activation has been shown to inhibit angiogenic and lymphangiogenic sprouting, we assessed the effect of VEGFA or -C stimulation on the 3D K-LECs. Interestingly, VEGFA/C stimulation induced a dramatic outgrowth of (lymph)angiogenic sprouts and inhibited the KSHV-induced EndMT in the 3D K-LECs. This suggests that the KSHV-induced Notch signaling and mesenchymal reprogramming can override the lymphangiogenic properties of LECs in the absence of VEGF-A/C stimulation. These results further corroborate the central role of Notch signaling as a critical determinant for the lymphangiogenic vs. mesenchymal fate of LECs. The 3D K-LEC transcriptome showed significant up-regulation of invasion related genes over the uninfected control. Intriguingly, comparison of the GEM profiles of the 3D K-LECs and KS biopsies, genes with similar co-regulation were found and included those involved both in EMT/EndMT and invasive processes. Using a panel of specific inhibitors we found a membrane associated matrix metalloproteinase MT1-MMP to be the major MMP involved in this process. Our data further identifies Notch as a previously unrecognized upstream regulator of MT1-MMP, and demonstrates that MT1-MMP as such is sufficient to induce EndMT in 3D cultured LECs. Mesenchymal markers and MT1-MMP were found co-distributed in the same cells with LANA in primary KS tumors suggesting that virus-induced EndMT may contribute to development of KS by giving rise to invasive cells, and providing the virus a permissive microenvironment for efficient spread of the viral genomes.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2976. doi:1538-7445.AM2012-2976
Abstract 2983: Nkx3.1 and c-Myc co-regulate shared target genes involved in prostate cancer
Authors: Anderson Philip D. , McKissic Sydika A. , Logan Monica , Roh Meejeon , Franco Omar , Wang Jie , Doubinskaia Irina , van der Meer Riet , Hayward Simon , Eischen Christine , Eltoum Isam-Eldin A. , Abdulkadir Sarki A.
Published: August 2012

Cooperativity between oncogenic mutations is recognized as a fundamental feature of malignant transformation, and may be mediated by synergistic regulation of the expression of pro- and anti-tumorigenic target genes. However, the mechanisms by which oncogenic mutations cooperatively regulate downstream target gene expression remain largely unknown. Here we used chromatin immunoprecipitation coupled with massively parallel sequencing (ChIP-seq) and gene expression analyses to identify direct targets of the prostate tumor suppressor Nkx3.1 in the mouse prostate. Our analysis showed that a significant fraction of Nkx3.1 targets are also targets of the oncoprotein c-Myc, suggesting that these two proteins may cooperate in prostate tumorigenesis by directly co-regulating a common set of target genes. Using ChIP, we confirmed binding of Nkx3.1 and c-Myc to the regulatory regions of shared target genes in mouse and human prostate epithelial cells. In conditional mutant mice, loss of Nkx3.1 cooperates with concurrent overexpression of c-MYC to promote prostate tumorigenesis. Furthermore, dysregulation of the shared NKX3.1/c-MYC target gene set was associated with relapse in human prostate tumors. We propose that co-regulation of target gene expression by oncogenic/tumor suppressor transcription factors may represent a general mechanism for the cooperativity of oncogenic mutations during tumorigenesis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2983. doi:1538-7445.AM2012-2983
Abstract 2991: Web-based access for whole genome analyses of gene expression, DNA copy number, microRNA transcript levels, drug activity, and their pattern comparisons for the NCI-60
Authors: Reinhold William C. , Sunshine Margot , Varma Sudir , Liu Hongfang , Weinstein John N. , Morris Joel , Doroshow James , Pommier Yves
Published: August 2012

High-throughput data is increasingly being integrated into the fields of biology, molecular biology, and pharmacology. However, a difficult problem has been the rapid and fluid access to and integration of this data, which tends to reside in huge unwieldy databases. One set of cell lines with substantial potential for benefit from this type of access and integration is the NCI-60 cancerous cell lines. We present here a set of tools within our CellMiner web-application designed to address this need for the areas of transcript expression, microRNA expression, gene DNA copy number, and drug activity. CellMiner allows the user to rapidly access data for relative levels of transcript expression for 18,532 genes, 360 microRNAs, and 16,861 compounds including 91 Food and Drug Administration (FDA)-approved drugs. These levels in turn create patterns across the NCI-60 that can be compared to one another using our “pattern match” tool. Together, these tools allow one to query the data for potential relationships between these parameters, in a manner specific to a users area of expertise and interest, in a rapid and flexible manner without the need for expertise in computer science or bioinformatics. The output will be demonstrated with cancer interesting microRNAs 18a, 21, 29a, 30c-2, 30d, and 31, cancer interesting genes ABCB1, ATM, ATR, BRCA2, and TP53, and the clinically relevant drugs belinostat, crizotinib, pazopanib, selumetinib and tanespimycin.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2991. doi:1538-7445.AM2012-2991
Abstract 2992: Analysis of divergent hypoxic gene expression data in prostate cancer cell lines suggests novel tumor progression biomarkers
Authors: Kimbro Kevin Sean , Rudd James , Tesfay Assefa , Zheng Gaolin , Williams-Devane Clarlynda
Published: August 2012

Decreased oxygen tension which can be caused by isolation of solid tumor cells from vascularization is hypothesized to lead cause migration, adaptation, or death. These cellular endpoints require transcriptional regulation of genes that are involved in numerous metabolic and physiological processes. We hypothesize those differences in transcriptional regulation account for variation of cellular response to a hypoxic environment (i.e. metastasis). To test this hypothesis, we characterized the difference in hypoxic gene expression of two isogenic cell lines (LnCap and C4-2) which differ in metastatic potential. In three independent experiments, cell lines (LnCAP and C-42) were incubated in a hypoxic or normoxic environment and pathway analysis was performed on the list of genes whose expression was significantly different. Analysis of the divergent hypoxic gene expression data (i.e. 641 genes) supported significant changes in starch and sucrose pathways (i.e. UDP glucoronosyltransferases), and cardiac arteriolopathy (i.e. DPP4). Differences in gene expression (i.e. 300 genes) between LNCaP and C4-2 were noted under normoxic conditions and included genes related to cell cycle (i.e. CDKN1B, JUNB, and CYR61) and cell differentiation (i.e. ID2, ID3, and HBP1). C4-2 cells are much more metastatic than LNCaP cells from which they were derived. Differences in response to hypoxia may reflect a strategy used by the C4-2 cell line to escape or survive in a hypoxic environment. Transcript profiles may have prognostic or diagnostic value for distinguishing the propensity for prostate cells to metastasize, and those genes that assist in hypoxic survival of C4-2 may be therapeutic targets for PCa. Continued investigation will identify the contributions of these genes to the metastatic process and clarify the downstream transcriptional networks involved in this facet of tumor progression.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2992. doi:1538-7445.AM2012-2992
Abstract 2995: Identifying subtypes of colorectal cancer tumors and cell lines with treatment relevance using iterative clustering (iNMF)
Authors: Beran Garry , Schlicker Andreas , Chresta Christine M. , McWalter Gael , Pritchard Alison , Weston Susie , Runswick Sarah , Davenport Sara , Heathcote Kerry , Alferez Denis , Orphanides George , French Tim , Wessels Lodewyk FA
Published: August 2012

Genetic and epigenetic features such as KRAS mutation status have been used to define colorectal cancer (CRC) subtypes and to take treatment decisions. In order to develop new targeted drugs, however, it is necessary to gain a better understanding of the molecular differences of CRC subtypes. We developed a new unsupervised approach for stratifying tumor samples using genome-wide mRNA expression data. Our method is based on the iterative application of non-negative matrix factorization (iNMF) on randomly selected sets of genes. In a sample set consisting of 63 CRC tumors, we identified two dominant subtypes. These subtypes were highly concordant with the epithelial-mesenchymal-transition (EMT) gene expression signatures consistent with recent publications. However further stratification of the tumor samples revealed five subtypes. These subtypes exhibit distinct differences, most notably differential activation of specific signaling pathways. Importantly, assessment of this method and derived subtype gene signatures stratified several independent, published datasets, suggesting that the signatures capture disease-relevant intrinsic features of CRC. Furthermore, application of the gene signatures to expression data obtained from three independent colon cell line panels revealed that the tumor subtypes were represented in all these different panels. Additional integration of pharmacological response data allowed us to identify several targeted compounds showing differential response across the subtypes. The CRC stratification obtained with our new method, iNMF, offers valuable insight into the differences between CRC subtypes at a functional level. Most importantly, it captures features of the disease that are highly relevant for the development of new targeted drugs in defined CRC patient sub-populations.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2995. doi:1538-7445.AM2012-2995
Abstract 3008: Shared gene expression alterations in prostate cancer and histologically benign prostate from patients with prostate cancer
Authors: Kosari Farhad , Cheville John C. , Ida Cristiane M. , Karnes R Jeffrey , Leontovich Alexey A. , Sebo Thomas J. , Erdogan Sibel , Murphy Stephen J. , Vasmatzis George
Published: August 2012

The frequent observations of heterogeneous tumor foci in prostate cancers indicate that the molecular changes induced by carcinogenic insult take place over wide areas within the diseased prostate. These ‘field effect’ alterations provide important clues regarding the initiation of prostate cancer (PCa) and suggest targets for cancer prevention or biomarkers for early detection. However, PCa field effect biomarkers that have passed independent validation are lacking largely because these alterations are subtle and difficult to distinguish from unrelated small changes in gene expression in the benign prostate. We postulated that shared expression alterations in PCa and in benign prostate tissue in prostate glands that contain prostate cancer (BPC) would have a higher potential for independent validation than alterations identified in BPC alone. Expression analyses was performed on PCa (n = 37) and unmatched BPC (n = 36) and contrasted with benign prostate glands (BP) from patients free of prostate cancer (n =28). These analyses identified gene alterations that were concomitantly present in both PCa and BPC. The majority of the selected markers were validated by quantitative RT-PCR in an independent set of BPC (n = 33) and BP (n =18). Validated markers included genes and non-exonic sequences not previously associated with PCa field effect. A statistical model based on CCNB1 and non-exonic NACA locus discriminated between BPC and BP in the RT-PCR set and in an external microarray dataset with accuracies of 0.84 and 0.90, respectively. Genes with predominant expression in prostate stroma were identified by expression profiling of stroma and epithelial cells collected by laser captured microdissection. Pathway analysis identified enriched GO categories in BPC stroma including PDGFR signaling. These results validate our approach for finding PCa field effect alterations and demonstrate a prostate cancer transcriptome fingerprint in the adjacent non-neoplastic cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3008. doi:1538-7445.AM2012-3008
Abstract 3074: NAD(P)H:quinone oxidoreductase 1 stabilizes C/EBPα from 20S proteasomal degradation leading to protection against myeloproliferative disease
Authors: Xu Junkang , Jaiswal Anil
Published: August 2012

NAD(P)H:quinone oxidoreductase 1 (NQO1) is a flavoprotein that protects cells against radiation and chemical induced oxidative stress. Disruption of NQO1 gene in mice leads to α-radiation-induced myeloproliferative disease. In the present study, we demonstrate that myeloid differentiation factor C/EBPα is degraded by 20S proteasome, and that NQO1 could salvage C/EBPα from 20S proteasomal degradation. Coimmunoprecipitation studies showed that NQO1, C/EBPα and 20S all interacted with each other. Deletion and site-directed mutagenesis studies demonstrated that NQO1 and 20S competed for the same binding region in C/EBPβ. Mutagenesis study also revealed that NQO1Y127/Y129 required for NADH binding is essential for NQO1 stabilization of C/EBPβ. Exposure of mice and HL-60 cells to α-radiation led to increased NQO1 and decreased 20S interaction with C/EBPβ, which resulted in stabilization of C/EBPα and protection against α-radiation-induced myeloproliferative diseases. This mechanism might provide day-to-day protection to bone marrow against adverse effects of radiation and chemical exposure, which has significant effect on individuals carrying hetero- or homozygous NQO1P187S mutation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3074. doi:1538-7445.AM2012-3074
Abstract 3079: Akt interacts and phosphorylates PHF20, a transcription factor binding to and inducing p53
Authors: Kim Donghwa , Park Sungman , Yan Fei , He Lili , Cheng Jin Q.
Published: August 2012

Akt regulates a diverse arrays of cellular function, including apoptosis, cellular proliferation, differentiation, and metabolism. While a number of molecules have been identified as upstream regulators or downstream targets, the mechanism by which Akt regulates these cellular processes remains elusive. Here, we identified a novel transcription factor, PHF20, which binds to Akt and p53. PHF20 is an evolutionarily conserved protein. We showed that PHF20 is a transcriptional factor and transactivates p53. Furthermore, the interaction of PHF20 and p53 led to stabilize p53. Akt phosphorylates PHF20 in vitro and in vivo, which resulted in change of PHF20 nuclear localization and disassociation of p53 from PHF20 as well as decrease of p53 expression at mRNA and protein levels. In addition, knockdown of PHF20 reduces whereas ectopic expression of PHF20 increases p53 expression. These data suggest that PHF20 is a novel substrate of Akt and plays an important role in maintaining normal p53 function.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3079. doi:1538-7445.AM2012-3079
Abstract 3083: Dual-specificity phosphatase-2 (DUSP2) negatively control cyclooxygenase-2 (COX-2) expression in cancer cells
Authors: Lin Shih-Chieh , Tsai Shaw-Jenq
Published: August 2012

Cyclooxygenase-2 (COX-2), an inducible form of cyclooxygenase, plays a crucial role in the development of cancer via its enzymatic product, prostaglandin E2 (PGE2). Clinical studies reveal that COX-2 is overexpressed in numerous types of cancers, and is associated with increase of angiogenesis, metastasis, and drug resistance. Although nonsteroidal anti-inflammatory drugs, COX-2 inhibitors, have been used for cancer therapy; they have serious side effects in many aspects. Therefore, to explore the underlying mechanism of COX-2 overexpression during cancer progression is critical for developing more efficient and safer way to block COX-2 function. Previously, we have found that the expression of dual-specificity phosphatase-2 (DUSP2), a MAPK-specific phosphatase, is markedly reduced in many kinds of cancers. Here, we identified that COX-2 was a potential downstream target gene of DUSP2. In vitro studies demonstrate that knockdown of DUSP2 significantly increases COX-2 expression and PGE2 production while overexpression of DUSP2 reduces those in cancer cells. Xenografted mouse study further reveals that levels of DUSP2 are reduced during cancer development, which is inversely correlated with COX-2 expression. Re-expression of DUSP2 during tumor progression inhibits COX-2 expression and suppresses tumor growth while knockdown of DUSP2 increases COX-2 expression and enhances tumor growth. These results implied that COX-2 overexpression was due to loss of DUSP2 expression in cancer. Furthermore, we found that hypoxia represses DUSP2 expression resulting in COX-2 overexpression. Taken together, we have demonstrated for the first time that aberrant expression of COX-2 during tumor development is regulated by hypoxia-mediated DUSP2 downregulation. Our data also suggest that DUSP2 is a good molecular target for cancer therapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3083. doi:1538-7445.AM2012-3083
Abstract 3084: Constitutively active RAS signaling reduces 1,25 dihydroxyvitamin D-mediated gene transcription by suppressing vitamin D receptor gene expression in mouse colon epithelial cells
Authors: DeSmet Marsha , Fleet James C.
Published: August 2012

The active metabolite of vitamin D, 1,25 dihydroxyvitamin D (1,25(OH)2D), binds to the vitamin D receptor (VDR) and stimulates anti-cancer transcriptional events in many cell lines including colon cancer cells. However, we found that tumors which form in the distal colon of mice with an APC allele deletion had significantly lower VDR mRNA levels compared to RNA isolated from the distal colon of wild-type mice (-92%, p≤0.05). These data suggest that colon carcinogenesis may impair 1,25(OH)2D-regulated chemoprevention in colon epithelial cells. APC inactivation and KRAS activation are early events in the development of distal colon that may suppress VDR gene expression. Compared to immortalized colonic epithelial cells derived from the “Immorto” mouse (YAMC), cells from a cross between APCmin and “Immorto” mice (IMCE), and YAMC cells overexpressing the v-Ha-RAS gene (YAMC-RAS) have significantly lower VDR mRNA (-80%; p≤0.05) expression. Previous research shows that constitutively active (ca) RAS signaling suppresses 1,25(OH)2D action in many cell lines so we conducted additional studies on the impact of this mutation. YAMC-RAS cells had a significant reduction in 1,25(OH)2D-induced CYP24 mRNA expression (-40%; p≤0.05). Consistent with lower VDR mRNA levels, YAMC-RAS cells also had lower VDR protein levels than YAMC cells and the suppression of 1,25(OH)2D-induced CYP24 expression in YAMC-RAS was overcome with VDR over-expression. The mechanism for RAS-mediated suppression of VDR mRNA levels was further explored. First we hypothesized that caRAS signaling expression reduced VDR mRNA stability, however, YAMC and YAMC-RAS cells treated with 4 µg/ml of the transcription inhibitor actinomycin D for up to 12 h had no significant difference in the VDR mRNA half-life (about 8 h). Next we examined whether caRAS signaling reduced accessibility within chromosomal regions in the VDR gene previously identified as necessary for VDR gene expression. Using a DNAse I hypersensitivity assay we found that in YAMC-RAS cells there was a significant reduction (p≤0.05) in chromosome accessibility on the proximal promoter (-23%, 300 bp upstream of exon 1), an enhancer region located 6 kb upstream of the transcriptional start site (-56%), and an enhancer region located in exon 2 (-100%) compared to the YAMC cells. These data show that caRAS signaling suppresses 1,25(OH)2D-mediated gene transcription in colon epithelial cells by reducing VDR gene transcription. Supported by NIDDK Award DK54111and AICR Award 09A098 to JCF

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3084. doi:1538-7445.AM2012-3084