New Horizons in Cancer Research: Targeting Breakthroughs - Harnessing Cures October 9-12, 2014 • Grand Hyatt Shanghai • Pudong, Shanghai, P.R. China Poster Session A – Friday, October 10, 2014, 12:30-3:00 p.m. A02 Therapeutic targeting of the histone demethylase KDM4 subfamily in breast cancer. Qin Ye, Andreana Holowatyj, Jack Wu, Hui Liu, Zeng-Quan Yang. Department of Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA. Breast cancer is a heterogeneous disease, consisting of tumors with varying pathologic and molecular characteristics. The primary biological subtypes of breast cancer include estrogen receptor–positive (ER+) tumors (luminal A and B), tumors that are human epidermal growth factor receptor 2 (HER2) –enriched, and tumors that are ER/PR-negative (basal-like). These molecular determinants have significant effects on disease pathophysiology, clinical outcome, and treatment response. ER+ tumors are generally associated with better clinical prognosis, whereas basal-like tumors are associated with higher rates of metastasis and death. The treatment for basal breast cancer consists of standard chemotherapy regimens, as no effective molecularly targeted therapy has been developed. New therapeutic options are likely to result from a growing understanding of both genetic and epigenetic abnormalities that participate in the different types of breast cancer, which helps to identify new subtype-specific targets for therapy. Aberrant histone lysine methylation, controlled by histone lysine methyltransferases and demethylases, plays significant roles in cancer initiation and progression. Previously, we demonstrated that histone demethylase KDM4C (also known as GASC1 and JMJD2C) is significantly amplified and overexpressed in aggressive basal-type breast cancer. The KDM4C/GASC1 protein belongs to the KDM4 family of histone demethylases, in which KDM4A, B, and C share more than 50% percent of sequence identity. KDM4A, B, and C contain JmjN, JmjC, PHD and Tudor domains, while the KDM4D protein lacks C-terminal PHD and Tudor domains. Jumonji domains of KDM4 mainly catalyze the demethylation of tri- and dimethylated histone 3 lysine 9 (H3K9me3/me2) and lysine 36 (H3K36me3/me2) marks, thus regulating chromatin structure and gene expression. The goal of this study is to analyze genomic anomalies and expression levels of KDM4 demethylases in different types of breast cancer, and to explore the therapeutic potential of a novel KDM4 demethylase inhibitor for treating aggressive breast cancer. First, we analyzed KDM4 demethylases expression in a panel of breast cancer cell lines and primary human tumors. We found that amplification and overexpression of KDM4A, C, and D were more prevalent in aggressive, basal-type breast cancer, while KDM4B overexpression was more prevalent in Luminal breast cancer. We further assessed global methylation (H3K4, H3K9 and H3K36) levels by using western blotting. We found that global levels of H3K9me3/me2 levels were lower in basal breast cancer cell lines. Using a novel KDM4 demethylase inhibitor, we demonstrated that inhibiting KDM4 demethylase activity blocks proliferation and cancer phenotypes of basal breast cancer. More importantly, transcriptome analyses revealed that KDM4 inhibitor can suppress expression of multiple genes that are critical in controlling cell growth and proliferation in breast cancer. In summary, our data indicate that KDM4 histone demethylase members might have distinct functions in promoting breast cancer development and progression, and that they are promising new targets for the epigenetic therapy of breast cancers. A03 Understanding the tumorigenicity of Phosphatase of Regenerative Liver-2 (PTP-PRL-2). E. Kostantin1,2, S. Hardy1, N. Uetani1, M.L. Tremblay1,2. 1Rosalind and Morris Goodman Cancer Research Centre, Montréal, Canada, 2Department of Biochemistry, McGill University, Montréal, Canada. The three Phosphatase of Regenerative Liver (PRL-1, -2, -3) enzymes have been identified as key contributors to tumor progression and metastasis in several human cancers, yet the molecular basis of their pro-oncogenic property is unclear. Our previous study identified the CNNM3 magnesium transporter as key binding partner of PRL2 in an evolutionarily conserved complex that regulates the intracellular magnesium concentration. Our discovery that PRL-2 controls magnesium levels, has led us to study its mechanism of action in complex with CNNM3, which could explain its oncogenic activity when highly expressed. More precisely, we examined if PRL- 2 tumorigenicity is dependent on the interaction with CNNM3. To do so, we generated several recombinant CNNM3 point mutants to identify PRL-2 interaction sites and their binding affinity was screened using pull-down assays. From those pull-down experiments, we infected cancer cell lines to stably express either wild type proteins or point mutants inhibiting the interaction. Proliferation was assayed using CyQUANT DNA dye, and anchorage independent tumor proliferation capacity was characterized by soft agar assay. Xenografts were performed with FVB mice injected with mouse cancer stable lines expressing our proteins of interest in order to investigate tumorigenic potential. Here, we show that a novel point mutation targeted in the CBS domain of CNNM3 was able to completely abolish the interaction with PRL-2. Since CNNM3 is a magnesium transporter, cancer cell lines expressing the mutation had significantly reduced proliferation. Supporting the role of this complex in cancer progression, the point mutation lowered the colony number of breast cancer cell line in anchorage independent soft agar assays. Most importantly, xenograft tumor assays expressing CNNM3 mutant that does not associate with PRL-2 drastically lowered tumor formation and size compared to wild type CNNM3 expression. In summary, exploring further details of this newly uncovered pathway would be a major breakthrough in understanding oncogenic activity of PRLs, and represents a new potential class of targeted therapeutics in cancer. A04 CD147 regulates malignant testicular germ cells apoptosis/survival through both extrinsic and intrinsic apoptotic pathways. Chaoqun Wang1, Hao Chen1, 2, Hsiao Chang Chan1. 1Epithelial Cell Biology Research Center, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, 2The Second People's Hospital of Shenzhen, Shenzhen, PR China. Testicular germ cell cancer is one of the most common types of cancer in men between the ages of 15 and 34 years. In the testis, the processes of germ cell proliferation and apoptosis are tightly controlled to maintain proper tissue homeostasis. Apoptosis, a programmed cell death, is thought to facilitate the removal of abnormal germ cells and to reduce the risk of cancer. Cluster of differentiation 147 (CD147), also named basigin or extracellular matrix metalloproteinase inducer (EMMPRIN), is a transmembrane glycoprotein, which has been reported to be highly expressed in various different types of cancer, including testicular germ cell cancer. Our previous studies have shown the involvement of CD147 in regulating spermatocyte apoptosis; however, the detailed mechanism remains elusive. In this study, we aimed to clarify the molecular mechanism underlying CD147-regulated testicular cancer cell survival/apoptosis with the mouse testicular germ cell cancer cell line P19 and human testicular germ cell cancer cell line NCCIT. We found that the cleaved caspase-8 was dramatically increased in anti-CD147 treated P19 and NCCIT cells, indicating that interference with CD147 induced activation of extrinsic apoptosis in testicular cancer cells. Further, the pro-apoptotic factors P53 and Bax were up-regulated and the anti-apoptotic factor Bcl-2 was down-regulated in anti-CD147 treated testicular cancer cells, suggesting that CD147 is also involved in regulating intrinsic apoptosis in testicular cancer cells. In addition, NFκB signaling, which is known to protect cancer cells from apoptosis, was down- regulated in the anti-CD147 treated cancer cells. These findings support an important role of CD147 in regulating testicular cancer cell survival, inhibition of which may promote apoptosis. A05 Regulation of Spindle Dynamics and Mitotic Fidelity by BCCIP. Steven Huhn, Jingmei Liu, Huimei Lu, Xing Feng, Zhiyuan Shen. CINJ Rutgers University, New Brunswick, NJ, The Rutgers Cancer Institute of New Jersey, Department of Radiation Oncology, Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, New Brunswick, NJ. During mitosis, the mitotic spindle apparatus is responsible for the faithful distribution of chromosomes between daughter cells. Compromised function of the mitotic spindle is a sufficient impetus of chromosome instability and aneuploidy, features associated with both tumor establishment and evolution. BCCIP, a p21 and BRCA2 interacting protein, is also intimately linked to chromosome instability and aneuploidy, yet the mechanisms through which BCCIP safeguards genomic stability are not completely understood. Here, we describe a novel role for BCCIP in regulating spindle microtubule dynamics during mitosis. We demonstrate that BCCIP accumulates at spindle poles and spindle fibers in dividing cells where it binds to tubulin and stabilizes microtubules. BCCIP loss results in the disappearance of the stable microtubule marker, K40-acetyl-tubulin, and sensitizes cells to the chemotherapeutic spindle poison, taxol. We show that this function