bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 914: The role of CD44 variant in the development of spasmolytic polypeptide-expressing metaplasia (SPEM) and gastric cancer
Authors: Wada Takeyuki , Nagano Osamu , Ishimoto Takatsugu , Oshima Hiroko , Oshima Masanobu , Masuko Takashi , Baba Hideo , Kitagawa Yuko , Saya Hideyuki
Published: June 2012

CD44 is a marker of tumor-initiating cells in gastric cancer. However, the cause or consequence of elevated CD44 in such immature tumor cells is not known. Gastric carcinogenesis involves a transition from normal mucosa to gastritis, which then leads to metaplasia and eventually adenocarcinoma. Although the emergence of metaplasia or dysplasia is a key event of inflammation-related gastric carcinogenesis, the precise mechanism underlying the transition from normal gastric epithelium to metaplasia and cancer remains unsolved. Spasmolytic polypeptide (known as trefoil factor family 2)-expressing metaplasia (SPEM) results from a metaplastic change of gastric epithelial cells in response to chronic inflammation. Here we show that the trefoil factor family 2 (TFF2)+ metaplastic glands as well as gastric tumor glands contain CD44 variant isoform-expressing (CD44v+) cells in K19-Wnt1/C2mE mouse, a genetic mouse model for gastric tumorigenesis. Furthermore, the analysis of three transgenic mouse lines K19-Wnt1, K19-C2mE and K19-Wnt1/C2mE revealed that de novo expression of CD44v in SPEM cells is triggered by prostaglandin E2-mediated signaling. Isolated CD44-expressing tumor cells in K19-Wnt1/C2mE mice by fluorescence-activated cell sorting (FACS) manifested increased expression of SPEM-related genes, suggesting that metaplastic epithelium might give rise to both of CD44v+ tumor cells and CD44v+ SPEM cells in mice. To investigate the role of CD44 in the development of SPEM and gastric tumor in mice, we generated CD44-/- K19-Wnt1/C2mE mice. We found that CD44 ablation significantly suppresses the development of SPEM and gastric tumor, suggesting that CD44v+ cells play a key role in gastric tumorigenesis. Furthermore, we found that the emergence of CD44v+ SPEM glands adjacent to cancer is tightly associated with the CD44v-expressing gastric cancer formation in human. Our present study thus suggest that SPEM cells might be susceptible for oncogenesis due to their proliferative capacity and that CD44v+ SPEM cells are cells-of-origin for CD44v+ tumor-initiating cells in human gastric adenocarcinoma.

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 914. doi:10.1158/1538-7445.AM2011-914
Abstract 917: mTOR kinase inhibition relieves feedback inhibition of RTK and PI3K signaling in breast cancer cells
Authors: Rodrik-Outmezguine Vanessa S. , Chandarlapaty Sarat , Cao Nen , Smith Paul , Guichard Sylvie , Rosen Neal
Published: June 2012

Activation of mitogenic signaling by receptor tyrosine kinases is regulated by negative feedback. Feedback is in part mediated by mTORC1/S6K dependent downregulation of IRS proteins which downregulate IGF/insulin receptor signaling. Rapamycin, an mTORC1 inhibitor, relieves this feedback and causes induction of phosphorylation of AKT at Serine 473 via IGF activation of mTORC2 leading to the activation of AKT kinase and signaling. This relief of feedback inhibition of mTORC2/AKT signaling may attenuate or abolish the antitumor activity of rapamycin. mTOR kinase inhibitors that inhibit both mTORC1 and mTORC2 complexes have now been developed to circumvent these problems. We now find that AZD8055 is a potent and selective inhibitor of both mTORC1 and mTORC2 and thus abolishes AKT phosphorylation at Ser473 as well as 4EBP1 and S6K phosphorylation, in contrast to rapamycin which effectively inhibits only the last and which activates the first. This drug potently inhibited the proliferation of tumor cells, especially those in which PI3K/AKT signaling is dysregulated and sometimes induced their death. However, AZD8055 does potently reactivate receptor tyrosine kinase signaling. It enhanced receptor tyrosine kinase phosphorylation and expression and caused a profound, HER-kinase dependent activation of ERK and PI3K signaling. It reactivated phosphorylation of AKT Thr308 and AKT substrates, but not that of Ser473 AKT. These data suggest that inhibition of the phosphorylation of AKT at Serine 473 is not sufficient to inhibit AKT signaling. Furthermore, relief of feedback inhibition of RTK function by mTOR kinase inhibitors leads to reactivation of both ERK and AKT signaling.

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 917. doi:10.1158/1538-7445.AM2011-917
Abstract 920: Mislocalization of the polarity protein Scribble promotes tumorigenesis in the mouse mammary gland
Authors: Feigin Michael E. , Rosenberg Avi Z. , Cardiff Robert D. , Muthuswamy Senthil K.
Published: June 2012

Recent evidence from our lab has demonstrated that the basolateral polarity protein Scribble is frequently mislocalized in human tumors and can cooperate with ErbB2 and Myc to induce mammary tumors. However, we do not know if mislocalization of Scribble can initiate cell transformation and tumorigenesis. To test the hypothesis that Scr mislocalization can induce tumorigenesis, we generated transgenic mice expressing a Scr point mutant that has been shown to mislocalize to the cytosol, under the control of the MMTV promoter (ScrP305L). ScrP305L mice develop mammary tumors with long latency, suggesting that secondary genetic events are required for tumor initiation. The tumors are histologically diverse, and immunohistochemical and gene expression analysis indicate that they express high levels of basal markers, including cytokeratins 5, 6 and 14, and low levels of the luminal marker E-cadherin. Inspection of the developing virgin mammary gland reveals that Scr mislocalization impairs tertiary branching and ductal density. While primary and secondary ducts appear normal, tertiary branches fail to form, suggesting a defect in luminal differentiation. These changes can be observed as early as eight weeks after birth; however, by one year of age, multifocal hyperplasias are apparent in most mice. We conclude that mislocalization of Scribble in the mouse mammary gland impairs luminal differentiation, resulting in branching defects and, through acquisition of secondary genetic events, tumors of varying histotype.

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 920. doi:10.1158/1538-7445.AM2011-920
Abstract 923: Separating the wheat from the chaff: A first look at the Cancer Cell Lines Encyclopedia sequencing data
Authors: Kryukov Gregory V. , Berger Michael F. , Stransky Nicolas , Barretina Jordi , Onofrio Robert , Caponigro Giordano , Sougnez Carrie , Monahan John , Shefler Erica , Venkhatesan Kavitha , Cibulskis Kristian , Morais Paula , Sivachenko Andrey , Meltzer Jodi , Lawrence Michael , Ramos Alex , Getz Gad , Platform Broad's Genome Sequencing , Thibault Joseph , Mahan Scott , Jones Michael , Morrissey Michael , Sonkin Dmitry , Ardlie Kristin G. , Golub Todd , Weber Barbara , Warmuth Markus , Sellers William , Harris Jennifer , Schlegel Robert , Garraway Levi A.
Published: June 2012

Comprehensive characterization of cancer genomic alterations and understanding their functional roles are important steps in the development of personalized cancer treatments. The Cancer Cell Lines Encyclopedia project aims to relate genomic alterations to drug sensitivity of cancer cells. Cancer cell lines are indispensable resource for researchers because of their convenience for high-throughput profiling and availability for follow-up experiments.

We sequenced the coding regions of 1645 genes in over 800 cancer cell lines representing 32 different tumor types. Genes were selected on their likelihood to be cancer-related and sequenced using next-generation Illumina technology after hybrid selection of exonic regions. Although, the absence of matched normal cell lines precludes direct distinction of somatic from germline mutations, we were able to select a subset of mutations highly enriched in somatic events combining the following three approaches: subtraction of known polymorphisms, prediction of strongly detrimental mutations (including computational predictions of amino acid substitutions’ effects on protein function) and detection of abnormal linkage disequilibrium patterns for recurring mutations.

We then searched for the three independent indicators of the potential involvement of mutated genes in cancer: the presence of an unusually high fraction of strongly damaging mutations within a gene, statistically significant deviation of distribution of mutations between cancer types from random expectation and clustering of mutations within a gene. Combined analysis of these lines of evidence revealed both known and novel potential tumor suppressors and oncogenes.

These data should become an import resource for cancer researchers in their search for personalized cancer therapies.

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 923. doi:10.1158/1538-7445.AM2011-923
Abstract 93: Usefulness of DNA methylation analysis using gastric washes as a treatment marker for early gastric cancer
Authors: Watanabe Yoshiyuki , Ohishi Yoshichika , Hiraishi Tetsuya , Oikawa Ritsuko , Maehata Tadateru , Suzuki Hiromu , Toyota Minoru , Itoh Fumio
Published: June 2012

Aim: Although minimal invasive treatment is widely accepted for early stage of gastric cancer, we still do not have any appropriate risk markers to detect residual neoplasia and some potential of recurrence. We previously reported that aberrant DNA methylation is an early and frequent process in gastric carcinogenesis and could be useful for detection of gastric neoplasia, and that methylation analysis of DNA recovered from gastric washes was used to detect gastric neoplasia (Gastroenterology 2009). Here, we hypothesized gastric washes also can determine whether gastric cancer (GCa) was removed curatively by endoscopic treatment or not. Our goal is to find and identify some candidate genes as a treatment marker using genome wide DNA methylation analysis and for early gastric cancer.

Method: We studied MCAM (Methylated CpG Island Amplification Microarray) analysis using 12 gastric washes (each 6 before and after endoscopic treatment in same patients) and identified candidate genes for further studies. Two of them are MINT25 and Sox17 (SRY (sex determining region Y)-box 17). We examined the DNA methylation status of these two genes in a validation set consisting of 128 washes samples (Pre, 64: Post, 64) at early gastric cancers by quantitative bisulfite-pyrosequencing analysis.

Results: These two genes showed significantly differential methylation between before and after treatment in GCa patient (MINT25, p<0.0001: Sox17, p<0.0001). Moreover, we could successfully identified the incomplete endoscopic mucosal resection case by Sox17 methylation status, and additional resection resulted in the proof of residual cancer and decrease of Sox17 methylation level in gastric wash.

Conclusion: We have developed a new methodology for gastric cancer detection by DNA methylation in gastric washes. It is easy and useful for early detection of recurrence after endoscopic treatment in GCa patients.

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 93. doi:10.1158/1538-7445.AM2011-93
Abstract 936: Ubiquitin-mediated interaction of p210 Bcr-Abl with β-catenin supports disease progression in a murine model for chronic myelogenous leukemia
Authors: Chen Ru , Mahon Gwen , Tala Ilona , Whitehead Ian
Published: June 2012

Chronic myelogenous leukemia (CML) is a malignant hematopoietic stem cell disorder that is invariably associated with the expression of the p210 Bcr-Abl fusion protein. Although the deregulated, Abl-encoded tyrosine kinase activity is essential for disease progression, several studies have shown that Bcr encoded sequences are also necessary for p210 Bcr-Abl-mediated leukemogenesis. We have identified a non-classical ubiquitin binding domain (UBD) within the NH2-terminal Bcr sequences of p210 Bcr-Abl. Deletion of the UBD (p210 Bcr-Abl(ΔUBD)) does not impair the auto-or trans-kinase activity of p210 Bcr-Abl, nor does it impair the ability of p210 Bcr-Abl to interact with Grb2 and activate Erk1/2 signaling. Although β-catenin has been previously identified as a binding partner for Bcr and Bcr-Abl, p210 Bcr-Abl(ΔUBD) does not interact with β-catenin. Treatment with an E1 inhibitor impairs the interaction between β-catenin and p210 Bcr-Abl, suggesting that the interaction is ubiquitin-dependent. Over-expression of p210 Bcr-Abl, but not p210 Bcr-Abl(ΔUBD), leads to an accumulation of phosphorylated β-catenin, and at least two of its known transcriptional targets, cyclin D1 and c-Myc. Hyper-phosphorylation of β-catenin cannot be attributed to increased activity of GSK-3β or Pin-1. In a murine bone marrow transplantation model for CML, mice transplanted with hematopoietic cells that express p210 Bcr-Abl(ΔUBD) have significantly increased life spans compared to mice transplanted with p210 Bcr-Abl expressing cells. Delayed disease progression is associated with decreased levels of β-catenin, and reduced numbers of granulocyte macrophage progenitors (GMPs), in the bone marrow. Based on these observations we propose a model in which p210 Bcr-Abl may influence the Wnt signaling pathway, and leukemic expansion, by binding ubiquitinated β-catenin, and stabilizing it against degradation. Importantly, this activity is contained within Bcr sequences, and is independent of tyrosine kinase activity.

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 936. doi:10.1158/1538-7445.AM2011-936
Abstract 938: Discovery of Dendrogenin A as the first endogenous alkylaminooxysterol present in mammals with potent cell differentiation and anticancer activity
Authors: Poirot Marc , de Medina Philippe , Paillasse Michael R. , Segala Grégory , Saati Tallal Al , Silvente-Poirot Sandrine
Published: June 2012

We recently reported that anti-tumor and chemopreventive drugs such as tamoxifen, raloxifene and docasahexaenoic acid are inhibitors at therapeutic doses of cholesterol epoxide hydrolase (ChEH), the enzyme that transforms cholesterol-5,6-epoxides (CE) into cholestane-3β,5α,6β-triol (CT) (de Medina et al, PNAS, 2010). Several lines of evidence point to the existence of an active metabolism centered on CE. We recently reported that the aminolysis of α-CE by biogenic amines under catalytic conditions generated powerful cell differentiating alkylaminooxysterols (de Medina et al, J Med Chem, 2009). Among these active molecules, Dendrogenin A (DDA) was synthesized, based on the hypothesis that it could be an endogenous metabolite formed by the reaction of α-CE with histamine at the level of the ChEH. In the present study, we report the existence of DDA in mammals at concentrations ranging from 70 to 500 pmol/g in tissues and at concentrations 70 to 500 times less in the circulation, while only trace levels of AF17, the regio-isomer of DDA, were detected. DDA was not found in a panel of cancer cells, suggesting a possible deregulation of its synthesis during oncogenesis. In addition, we showed that DDA is the most potent natural inhibitor of ChEH with an IC50 around 100 nM and it exhibits tumor differentiation and anti-tumor activity in cell and animal models. In vivo, these effects were associated with a T cell-mediated anti-tumor response. AF17 was found to be inactive in these different tests, showing a regio-selectivity of action of these compounds. In conclusion, our results shed light on a new metabolic pathway that generates the first endogenous steroidal alkaloid ever described in mammals that may have important functions in maintaining cell integrity and differentiation as well as immune system alert. The discovery of DDA reveals an unexpected cross-talk between cholesterol and histamine metabolism.

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 938. doi:10.1158/1538-7445.AM2011-938
Abstract 941: Targeting androgen receptor in estrogen receptor-negative breast cancer
Authors: Ni Min , Chen Yiwen , Bailey Shannon T. , Imai Yuuki , Liu X. Shirley , Brown Myles
Published: June 2012

Estrogen receptor (ER)-negative breast cancers account for 25-30% of all breast cancer cases and generally have a poor prognosis and little benefit from current endocrine therapy. Androgen receptor (AR) is expressed in 60-70% of human breast tumors independent of the ER status. Interestingly, while androgens inhibit the growth of ER+/AR+ breast cancer cells, they stimulate the growth of those that are ER-/AR+. However, the mechanism by which androgens and AR function to regulate breast cancer growth remains largely unknown. Analysis of gene expression microarray datasets from human breast tumors reveals enriched expression of AR in the ER- breast tumors that over-express HER2. Genome-wide analysis of the AR binding sites and androgen-regulated gene expression profiles in ER-/HER2+ breast cancer cells identified that AR mediates activation of oncogenic Wnt and HER2 signaling pathways through direct transcriptional up-regulation of WNT7B and HER3 in an androgen-dependent manner. Importantly, we demonstrate that FOXA1 and beta-catenin act as AR coactivators in inducing HER3, leading to the enforced HER2/HER3 signaling. Pharmacological inhibition of AR, Wnt or HER2 pathways impairs HER3 activation and androgen-stimulated tumor cell growth. While HER3 is receiving increased attention as a therapeutic target in HER2+ breast cancer, our study suggests that AR regulation may be yet another way to target HER3 in ER-/HER2+ tumors. Collectively, these findings not only highlight a previously unappreciated role of AR in breast cancer, but also reveals the mechanistic basis for targeting AR as a novel therapeutic opportunity for patients with invasive ER-/HER2+ breast 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 941. doi:10.1158/1538-7445.AM2011-941
Abstract 945: Metabolic syndrome increases the risk of primary liver cancer in the United States
Authors: Welzel Tania M. , Graubard Barry I. , Davila Jessica A. , El-Serag Hashem B. , McGlynn Katherine A.
Published: June 2012

Background: Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) are the two most common histologic types of primary liver cancer. Incidence rates of both HCC and ICC are increasing in the United States. Metabolic syndrome, characterized by increased fasting glucose level, central adiposity, dyslipoproteinemia and hypertension, has been linked with HCC and may also modify the risk of ICC. The magnitude of the association, however, has not been investigated at the population level in the US. We therefore examined the association between metabolic syndrome and the development of both primary liver cancers in the general U.S. population.

Methods: All persons aged 65 years and older diagnosed with histologically confirmed HCC and ICC between 1993 and 2005 were identified in the SEER-Medicare linked database. The cases were compared to a 5% sample of individuals residing in the same geographic regions of the SEER registries as the cases. The prevalences of metabolic syndrome and other risk factors for HCC (HBV, HCV, unspecified viral hepatitis, alcoholic liver disease, unspecified cirrhosis, biliary cirrhosis, hemochromatosis, Wilson's disease, smoking) and ICC (biliary cirrhosis, cholangitis, cholelithiasis, choledochal cysts, HBV, HCV, unspecified viral hepatitis, alcoholic liver disease, non-specified cirrhosis, inflammatory bowel disease, Crohn's disease, ulcerative colitis, smoking) were compared among the persons who developed cancer and the persons who did not. Adjusted odds ratios and 95% confidence intervals were calculated using logistic regression.

Results: A total of 3,649 HCC cases, 743 ICC cases and 195,953 persons without cancer met the study inclusion criteria. Metabolic syndrome was significantly more common among persons who developed HCC (37.1%) and ICC (29.7%) than among persons who did not (17.1%, p<0.0001). In multiple logistic regression analyses that adjusted for demographics features and the other risk factors, metabolic syndrome remained significantly associated with an increased risk for HCC (OR=2.13; 95%CI=1.96-2.31, p<0.0001) and ICC (OR=1.56; 95% CI = 1.32-1.83, p<0.0001).

Conclusions: Metabolic syndrome is a risk factor for development of both HCC and ICC in the general U.S. population. Given that approximately one-third of U.S. adults have metabolic syndrome, these findings have implications for the future incidence of both HCC and ICC.

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 945. doi:10.1158/1538-7445.AM2011-945
Abstract 959: Targeting renal cell carcinoma with englerin A
Authors: Sourbier Carole , Ratnayake Ranjala , Scroggins Brad , Lee Min-Jung , Lee Sunmin , Trepel Jane , Beutler John , Neckers Len , Linehan W. Marston
Published: June 2012

Background: Englerin A (EA) is a natural product which has shown selective toxicity toward kidney tumor cells in the NCI60 panel. However, EA's targets and mechanism of action remain unknown.

Methods: Cytotoxicity of EA toward a panel of kidney cancer cell lines was assessed in vitro by MTT and cell counting, and in vivo using a human clear cell kidney cancer xenograft mouse model. The protein kinase C family was predicted as a likely molecular target of EA using QSAR methodology. This was confirmed by PKC kinase activity assays. EA's mechanism of action was investigated using western-blot analysis, meso-scale discovery technology, and immunohistochemistry.

Results: EA was cytotoxic in vitro and in vivo via induction of apoptosis. Comparison of EA's structure with other well-known compounds predicted the PKC family to be a potential drug target. Direct treatment of cell lysates with EA increased pan-PKC kinase activity, suggesting that EA directly activated at least one of the PKC isoforms. Further investigation showed that EA-dependant PKC activation inhibited the insulin pathway through inhibitory phosphorylation of Insulin Receptor Soluble 1 (IRS1) protein, and decreased phosphorylation status of Akt and GSK3beta. These data were reproduced in vivo, as phosphorylation of GSK3beta was reduced in RCC tumor treated with EA compared to tumor treated with vehicle.

Conclusion: The insulin/PI3K/Akt pathway has been previously shown by us and others to be critical for the survival of renal cell carcinoma. By activating PKCs, EA indirectly induces an “insulin resistant” phenotype which appears to be selectively lethal for RCC tumor cells. Thus, EA represents a novel potential therapeutic lead for renal 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 959. doi:10.1158/1538-7445.AM2011-959
Abstract 966: Snail mediated transcriptional repression and EMT requires zinc-finger and SNAG domain directed phosphorylation: Identification of the kinases and evaluation as therapeutic targets
Authors: Rauscher Frank J. , Hou Zhaoyuan , Peng Hongzhuang , White David E. , Wood Colleen
Published: June 2012

The Snail zinc-finger transcription factor is a master regulator of the Epithelial-Mesenchymal Transition (EMT) which occurs during the early steps in tumor metastasis. Snail is strongly up-regulated and causally involved in EMT: it binds directly to the promoters of genes which mediate EMT and functions largely as a repressor thereby regulating a comprehensive transcriptome which establishes and maintains the invasive mesenchymal phenotype. Snail is a marker for the malignant phenotype, prognosis and strongly predicts treatment failure, relapse and overall survival. Inhibiting the Snail pathway is a novel approach to metastasis prevention and therapeutics. We have: 1) identified the LIM protein AJUBA as a novel co-repressor for Snail-mediated EMT; 2) shown that the arginine methyltransferase 5 (PRMT5) complex is recruited to SNAIL through AJUBA and; 3) discovered that Snail/AJUBA/PRMT5 complex assembly in chromatin requires that the zinc-finger region of Snail be phosphorylated at serine/threonine residues in the DNA binding and repression domains and that these modifications are directly recognized by 14-3-3 proteins. The quaternary pSnail/AJUBA/PRMT5/14-3-3 complex is enriched at endogenous Snail target genes via ChIP. Mutation of the target amino acids Serine11 and Threonine177 to alanine concommitantly abolished: 14-3-3 binding, chromatin association of the complex, and transcriptional repression. Moreover, Snail induction of EMT and metastasis was inhibited. These studies suggest that targeting the Snail directed kinases for inhibition is a viable strategy for controlling tumor progression and metastasis. The Identification of these kinases and their regulation during tumor progression will be presented.

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 966. doi:10.1158/1538-7445.AM2011-966
Abstract 967: N-Myc interactor, a novel regulator of EMT
Authors: Devine Daniel J. , Andrews Joel , Rostas Jack , Shevde Lalita A. , Samant Rajeev S.
Published: June 2012

Dissemination of tumor cells and subsequent colonization at distant sites is the most lethal event in cancer progression. The epithelial-mesenchymal transition (EMT) has recently been recognized as a foremost phenomenon underlying such events. Because of the importance of EMT, it is vital to understand what triggers it, as well as the mechanisms by which it is regulated. We have shown that N-myc interactor (NMI) plays a role in restricting malignant activities of cancerous cell lines in vivo and in vitro. This study describes a novel function of NMI in reducing the mesenchymal phenotype of breast cancer cell lines.

Constitutive expression of NMI in the mesenchymal cell line MDA-MB-435, showed remarkable morphologic transition towards an epithelial appearance, accompanied by reduction or loss of several mesenchymal markers such as TWIST, MMP2, SNAI2 and ZEB1 and gain of epithelial markers such as E-cadherin and Keratin 18. Conversely, silencing NMI from immortalized breast epithelial line MCF10A, renders the cells more mesenchymal in appearance. Studies using a variety of additional cell lines consistently revealed that silencing of NMI expression coincided with increased expression of both ZEB1 and SNAI2, while NMI overexpression brought about decreased expression of ZEB1 and SNAI2.

Assessment of NMI in breast cancer specimens revealed a significant loss of NMI transcript with increasing grade of breast cancer. Thus, overall, our data strongly suggests that loss of NMI may be a key event allowing increased expression of EMT-inducing transcription factors that drive EMT-dependent malignant progression.

Acknowledgement: We acknowledge grant support from the NCI: 1R01CA140472

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 967. doi:10.1158/1538-7445.AM2011-967
Abstract 970: Obesity promotes melanoma metastasis by modulating Snai1 and KiSS1 expression
Authors: Kushiro Kyoko , Nunez Nomeli P.
Published: June 2012

Malignant melanoma accounts for 75% of deaths associated with skin cancer. Its lethality comes from its aggressive metastasis to secondary sites such as the lungs. Epidemiological and animal studies suggest that obesity may increase the ability of melanomas to metastasize. The objective of these studies was to determine the mechanism by which obesity increases the aggressiveness of melanomas to metastasize. To this end, we used ob/ob mice as a model of obesity, as well as different cell culture conditions which mimic obesity, to investigate the molecular mechanism by which obesity affects the metastatic phenotype of B16BL6 mouse metastatic melanoma cells in vitro. In cell culture, we showed that serum from obese mice increased the ability of melanoma cells to invade. We showed that both obese mouse serum and conditioned medium collected from mature 3T3L1 adipocytes promoted a mesenchymal phenotype, as seen by an increased expression of genes associated with this phenotype, such as Snai1, and a corresponding decreased expression of the metastasis suppressor gene KiSS1. Our preliminary results suggest that obesity may increase the metastatic ability of melanomas via the pro-inflammatory cytokine Interleukin 6 (IL-6). Therefore, our hypothesis is that obesity promotes melanoma metastasis by promoting the epithelial-to-mesenchymal transition (EMT) and its associated phenotypic changes by up-regulating Snai1 and down-regulating KiSS1 through IL-6. These findings will help us understand how obesity affects melanoma metastasis and allow us to identify key cellular signaling pathways that can be used to prevent or possibly inhibit melanoma metastasis.

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 970. doi:10.1158/1538-7445.AM2011-970
Abstract 989: Profiling the expression of SGLT1 in prostate cancer
Authors: Blessing Alicia , Weihua Zhang
Published: June 2012

Upregulation of the epidermal growth factor receptor (EGFR; HER1; erbB1), a receptor tyrosine kinase, has been linked with increased cell proliferation and decreased apoptosis and thus, with poor prognosis for cancer patients. EGFR has been found to be over-active in most tumors of epithelial origin including: non-small cell lung cancer, breast, head and neck, gastric, colorectal, esophageal, prostate, bladder, renal, pancreatic, and ovarian cancers. EGFR is elevated in prostate cancer cells along disease progression. EGFR tyrosine kinase inhibitors failed to show beneficial effects for prostate cancer patients. Previous studies have found EGFR has kinase independent prosurvival functions. Independent of its kinase activity, EGFR participates in the maintenance of the basal intracellular glucose level of cancer cells by interacting with and stabilizing SGLT1, thus preventing cancer cells from autophagic death. EGFR and SGLT1 do physically interact; however, it was previously unknown whether SGLT1 expression is upregulated along prostate cancer progression. Sodium-dependent glucose co-transporters (SGLTs) are transmemebrane glucose transporter proteins involved in the active transport of glucose. An antibody against human SGLT1 was made and used with immunohistochemistry to show in this preliminary study that SGLT1 is exclusively expressed in the hyperplastic and malignant prostate epithelial cells. SGLT1 was not expressed in the normal epithelial or BPH cells. The results from this study indicate that as the disease progresses, the increased need for glucose within the cells is at least in part being met by the continuous activity of the sodium-dependent glucose co-transporter 1. This potential role of SGLT1 in prostate cancer may provide avenues for new prostate cancer treatments. Future endeavors will focus on designing interfering peptides that ideally will interfere with the SGLT1/EGFR binding, destabilizing SGLT1 in prostate cancer cells, and promoting cell death of prostate 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 989. doi:10.1158/1538-7445.AM2011-989
Abstract 996: SFRP1 reduction results in an increased sensitivity to TGF-β signaling
Authors: Gauger Kelly , Schneider Sallie Smith , Chenausky Kerry , Murray Molly
Published: June 2012

Metastasis remains the most deadly aspect of breast cancer. We previously published that when the Wnt/β-catenin signaling antagonist, secreted frizzled-related protein-1 (SFRP1), is knocked down in immortalized non-malignant mammary epithelial cells, the cells (TERT-siSFRP1) exhibit a malignant phenotype which resembles the characteristics observed in metastatic breast cancer. Interestingly, the observed phenotypic and genotypic changes that occur in response to loss of SFRP1 define the EMT process. Among the genes analyzed, the drastic increase in ZEB2 expression was of particular interest to us. This protein is a zinc-finger transcription factor that represses the expression of E-cadherin, which is the mechanism by which ZEB2 is thought to contribute to EMT. Additionally, ZEB2 has been shown to interact with downstream mediators of Transforming Growth Factor (TGF)-β signaling (SMADs). TGF-β signaling is known to actively contribute to the acquisition and development of metastatic phenotypes in part through its ability to stimulate EMT and we wondered whether this cytokine plays a role in the EMT observed in response to SFRP1 loss. Therefore, we tested the hypothesis that TGF-β signaling is augmented due to SFRP1 reduction. First, we used luciferase assays and real-time PCR analysis to show that in response to TGF-β treatment, the expression of TGF-β responsive genes are elevated in TERT-siSFRP1 cells. These downstream targets were also measured after cells were treated with a TGF-βR antagonist (LY364947) to ensure these effects were specifically due to the TGF-β signaling pathway. TGF-β signaling has also been shown to increases the phosphorylation of ERK1/2 which in turn enhances cellular migration. We found that the migratory TERT-siSFRP1 cells exhibit a marked increase in ERK1/2 phosphorylation that is readily blocked by the addition of LY364947. Furthermore, transwell assays revealed that LY364947 blocks cellular migration and this phenomenon is likely due to the inhibition of ERK1/2 because the ERK1/2 inhibitor (U0126) similarly blocks cellular migration. To investigate the contribution of ZEB2, we used siZEB2 oligonucleotides to knock down the expression of this protein. Reduced levels of ZEB2 lowered the expression of exogenous and endogenous TGF-β transcriptional targets and hindered cellular migration. We can conclude from these data that the TGF-β signaling pathway is aberrantly activated in TERT-siSFRP1 cells due to the significant up-regulation of the SMAD-interacting protein, ZEB2.

This work has been supported in part by the Rays of Hope Foundation.

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 996. doi:10.1158/1538-7445.AM2011-996
Abstract 997: Stability of β-catenin decides the tumor suppressive effect of MRJ
Authors: Menezes Mitchell E. , Mitra Aparna , Shevde Lalita A. , Samant Rajeev S.
Published: June 2012

Mammalian relative of DnaJ (MRJ), is a member of the heat shock protein 40 family. We have found that MRJ is lost in advanced grades of breast cancer. Functional studies showed that ectopic expression of the large spliced variant of MRJ, MRJ(L), results in reduced malignant properties as indicated by reduced motility, migration, invasion and soft agar colonization. Furthermore, xenograft studies in athymic mice showed that MRJ(L) expression reduced tumor growth and metastasis. Our investigations also revealed that Wnt/β-catenin signaling is one of the pathways impacted by MRJ(L) expression. Specifically, we found that MRJ(L) expression led to enhanced degradation of β-catenin. Our studies showed that MRJ(L) mediated its tumor suppressive effects by upregulation of DKK1, a negative regulator of Wnt/β-catenin signaling, which promotes proteosome mediated degradation of β-catenin. Hence, we hypothesized that introduction of a degradation-resistant form of β-catenin will lead to restoration of malignant attributes of the MRJ(L) expressing cells. S37A mutation of β-catenin has been known to render it insensitive to ubiquitination-mediated proteosomal degradation. We established stable clones co-expressing S37A β-catenin and MRJ(L). Our analysis of these clones showed that the TCF/LEF activity, as a measure of Wnt/β-catenin signaling, was elevated 10 fold, as measured by the increased activity of the luciferase reporter, TOPFlash. We also found that downstream transcriptional target of Wnt/β-catenin signaling, cyclin D1 showed increased expression in S37A β-catenin clones as compared to the MRJ(L) expressors. Synchronized cell cycle analysis demonstrated that cells co-expressing S37A β-catenin and MRJ(L) resulted in marked increase in S phase at 2 and 24 hours after the release of cell cycle block. The MRJ(L) expressors; did not go through an increase in the S phase in the 24 hour period after the release. Analysis of tumor growth in vivo (xenograft model) revealed that S37A β-catenin was able to restore the malignant activity overriding the suppressive effect of MRJ(L). Thus controlled degradation of β-catenin, brought about by MRJ(L), is an important event in maintaining cells in a non-tumorigenic state.

Acknowledgement: We acknowledge grant support from the NCI: 1R01CA140472

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 997. doi:10.1158/1538-7445.AM2011-997
Abstract 998: Downregulation of survivin suppresses uPA through transcription factor JunB
Authors: Lee Kyung Hee , Koh Sung Ae , Lee Ha Young , Kim Min Kyoung , Kim Kyeong Ok , Lee Se Young , Jang Byung Ik , Kim Se Won , Kim Sang Woon , Song Sun Kyo , Kim Jae-Ryong
Published: June 2012

Background: Survivin, identified member of the inhibitor apoptosis protein family, is expressed during development and in various human cancers. However, lts role of clinical relevance in cancers are sill debated.

Purpose: We investigated the role of HGF induced activation of a transcription factor JunB, in the expression of survivin and uPA.

Methods and Results: Genes induced by HGF were screened by using cDNA microarray technology in stomach cancer cell lines, NUGC3 and MKN28. Expression level of surviving and JunB was further confirmed by read time RT-RCR and western blot analysis. Roles of JunB and survivin in the levels of HGF induced up-regulation of uPA were measured by knock down of survivin with survivin siRNA and chromatic immuno- precipitation assay. The levels of JunB, survivin and uPA were up regulated in cells treated with HGF in a dose dependent manner. HGH-induced up regulations of JunB, surviving, and uPA were inhibited by the pretreatment with an MEK inhibitor, PD 098559. HGH-induced up-regulation of uPA were repressed by survivin knockdown. HGF enhanced the binding activity of JunB to the enhanced the binding activity of JunB to the survivin promoter in control cells, but not in the JunB-sh RNA cells. Transfection with survivin-sh RNA results in decrement of cell proliferation as determined with MTT assays. In an in vitro invasion assay, significantly fewer cells transfected with survivin sh-RNA than control cells were able to invade across a matrigel membrane barrier.Conclusion: Survivin might play an important role in the up-regulation of uPA induced by HGF via JunB and contribute to HGF-mediated tumor invasion and metastasis, which might be promising target for stomach 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 998. doi:10.1158/1538-7445.AM2011-998
Abstract LB-10: A gene expression signature reflects the regulatory status of Wnt/β-catenin pathway activity
Authors: Wu Zhong , DiCarlo John , Wang Yexun
Published: June 2012

Due to limitations of cytotoxic based chemotherapies, current oncology drug development is designed to target specific cellular signaling pathways critical for tumor growth and progression. Such targeted drug development requires specific biomarkers to monitor the activity status of pathway. Compared to the traditional method which relies on one or a few indicators within the pathway constituents, multi-gene expression based methods measure pathway alteration as a function of the downstream effect of pathway regulation on multiple gene expression changes. These downstream gene expression alterations can potentially capture all changes related to any upstream alteration of a pathway component. The Wnt/β-catenin pathway is one of the most frequently altered pathways in a number of human cancers including colorectal carcinomas, melanomas, breast cancer and hepatocellular carcinomas and therefore of major interest to cancer researchers. Activation of the Wnt/β-catenin pathway results in a variety of downstream biological effects and this functional diversity is reflected in gene expression changes. By utilizing Wnt3a stimulation and siRNA mediated β-catenin knockdown in 293H cells followed by gene expression profiling analysis, we identified a list of 64 genes whose expression was upregulated in response to Wnt3a and whose increased expression levels were diminished by treatment with β-catenin siRNA. These 64 Wnt/β-catenin response genes were further evaluated by real-time PCR with 11 samples from a panel of 10 different cell lines either stimulated with Wnt3a and LiCl and/or inhibited with β-catenin siRNA. Sixteen genes were identified as a specific panel of indicators for Wnt/β-catenin pathway regulation using a nearest shrunken centroid classifier method. To further verify the 16 gene signature, we applied the signature to 10 new samples from 9 different cell lines in which 5 samples were stimulated with Wnt3a or LiCl and the rest of them were from cells transfected with β-catenin siRNA. The 16 gene signature predicted the regulatory status of Wnt/β-catenin pathway in these 10 samples with an accuracy of 100%. Our study demonstrates the identification and initial verification of a gene expression signature that can potentially serve to monitor the regulatory status of cellular Wnt/β-catenin pathway activity.

The applications presented here are for research use only. Not for use in diagnostic procedures.

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 LB-10. doi:10.1158/1538-7445.AM2011-LB-10
Abstract LB-104: The histone deacetylase SIRT2 regulates the cell proliferation and tumorigenicity of glioblastoma cancer stem cells
Authors: Funato Kosuke , Nasu-Nishimura Yukiko , Echizen Kanae , Todo Tomoki , Ino Yasushi , Saito Nobuhito , Koyama-Nasu Ryo , Oda Takeaki , Akiyama Tetsu
Published: June 2012

Despite huge efforts, glioblastoma has remained one of the most intractable tumors. According to the cancer stem cell theory, the aggressive phenotype and poor prognosis of glioblastoma are attributed to the rare tumor cells called glioblastoma cancer stem cells (GSCs), which are poorly differentiated and share features with neural stem cells. However, the molecular mechanisms underlying the tumorigenicity and stemness of GSCs are still to be elucidated. In this study, we performed an RNA-interference (RNAi)-based screen and identified 29 genes that positively regulate the expression of CD133. Among these, we focused on the histone deacetylase SIRT2. When the function of SIRT2 was inhibited by RNAi or the specific inhibitor AGK2, sphere-forming capacity and cell proliferation were significantly decreased. In addition, knockdown of SIRT2 induced apoptosis in GSCs but not in “serum-differentiated” GSCs, suggesting a stem-cell specific function of SIRT2. Furthermore, GSCs in which SIRT2 expression was stably repressed by a specific small hairpin RNA (shRNA) showed impaired tumorigenicity when transplanted into immunocompromised mice. Taken together, these results imply that SIRT2 is a possible therapeutic target for glioblastoma and the existing SIRT2 inhibitors should be useful seed compounds for novel antitumor drugs.

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 LB-104. doi:10.1158/1538-7445.AM2011-LB-104
Abstract LB-112: SP1 suppression is associated with poor prognosis in intestinal-type gastric adenocarcinoma
Authors: Lee HunSeok , Erkin Özgür Cem , Oh Ensel , Kwon Mi Jeong , Shin Young Kee
Published: June 2012

Specificity protein 1 (SP1) is a DNA-binding protein that activates and regulates the transcription of multiple genes. Since aberrant expression of SP1 was known to be related to cancer development and progression, we focused on SP1 expression in gastric cancer and its correlation with disease outcomes. We discovered a different relationship between SP1 expression and patient survival in intestinal and diffuse-type gastric cancer. In diffuse-type gastric cancer, patient survival decreased as SP1 expression increased (P < 0.05) in accordance with previously published papers, whereas the lack of SP1 expression in intestinal-type gastric cancer was correlated significantly with poor survival (P < 0.05). Multivariate analysis demonstrated that SP1 downregulation is an independent negative prognostic factor in intestinal-type gastric cancer. When SP1 downreguation was forced in high SP1 expressor intestinal-type gastric cell line MKN28 with siRNA, both migration and invasion was increased but cell proliferation was decreased. In accordance with these results, microarray data in siRNA-transfected MKN28 showed that genes inhibiting migration were downregulated and the expression of genes negatively facilitating proliferation was increased. Both migration and invasion, however, in low SP1 expressor intestinal-type gastric cell line AGS was decreased by SP1 induction. In contrast to intestinal-type, in diffuse-type gastric cell line SNU484, high SP1 expressor, both migration and invasion were decreased by siRNA. Contrary to previous studies, which did not reflect differences between the 2 histological types, our results showed that weak SP1 expression is involved in cancer progression and metastasis, and leads to poor prognosis in intestinal-type gastric adenocarcinoma.

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 LB-112. doi:10.1158/1538-7445.AM2011-LB-112