Abstract NTOC-110: UNEXPECTED ROLES FOR KDM4A: PROTEIN SYNTHESIS AND MTOR INHIBITOR SENSITIVITY

Abstract

Abstract Single nucleotide polymorphisms (SNPs) occur within chromatin-modulating factors; however, little is known about how these variants within the coding sequence impact cancer progression or treatment. Therefore, there is a need to establish their biochemical and/or molecular contribution, their use in sub-classifying patients and their impact on therapeutic response. We demonstrate that coding SNP-A482 within the lysine tri-demethylase KDM4A/JMJD2A associates with differential outcome in cancer patients and promotes KDM4A protein turnover. Interestingly, homozygous SNP-482 cells have increased mTOR inhibitor sensitivity. mTOR inhibitors significantly reduce SNP-A482 protein levels, which parallels the increased drug sensitivity observed with KDM4A depletion. Furthermore, we demonstrate that KDM4A interacts with the translation initiation complex and impacts the distribution of translation initiation factors within polysome fractions. Upon KDM4A depletion, protein synthesis was reduced and there was enhanced protein synthesis suppression with mTOR inhibitors, which paralleled an increased sensitivity to these drugs. Lastly, we demonstrate that JIB-04, a JmjC demethylases inhibitor, suppresses translation initiation and enhances mTOR inhibitor sensitivity. These data highlight an unexpected role for KDM4A in regulating protein synthesis, in modulating mTOR inhibitor sensitivity and suggest potential novel therapeutic applications for this class of enzyme. Citation Format: Capucine Van Rechem, Joshua C. Black, Patricia Greninger, Yang Zhao, Myriam Boukhali, Carlos Donado, Martin J. Aryee, Paul d. Burrowes, Brendon Ladd, Susanne Gräslund, Wilhelm Haas, David C. Christiani, Cyril H. Benes and Johnathan R. Whetstine. UNEXPECTED ROLES FOR KDM4A: PROTEIN SYNTHESIS AND MTOR INHIBITOR SENSITIVITY [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr NTOC-110.