Abstract LB193: Lysine demethylase 5A is required for MYC driven transcription in multiple myeloma

Multiple myeloma (MM) is a malignant plasma cell disorder accounting for 10% of hematologic malignancies. Although high dose chemotherapy and targeted agents have improved patient outcomes, MM remains an incurable disorder. Thus, there is an urgent need to develop novel therapeutic strategies. We discovered that the distinct lysine demethylase 5A (KDM5A) plays a critical role in MM cell growth, through a unique link to MYC-driven transcriptional programs. KDM5A is a dominant regulator of histone H3K4 trimethylation, a histone mark associated with activated gene transcription. We identify that KDM5A interacts with P-TEFb complex and cooperates with MYC to control MYC targeted genes in MM cells. We develop a novel, cell-permeable and selective KDM5 inhibitor, JQKD82 that increases histone H3K4me3, and inhibits downstream MYC-driven transcriptional output in vitro and in vivo. Utilizing genetic ablation together with our inhibitor, we established a detail mechanism that KDM5A is required for transcriptional pause release by P-TEFb at MYC target genes. These data identify KDM5A as a unique vulnerability in MM through regulation of the driving MYC oncogene in MM, and defined JQKD82 as a tool compound to block KDM5A function as a potential therapeutic strategy for MM. Citation Format: Jun Qi, hiroto Ohguchi, Paul MC Park, tingjian wang, Kenneth C. Anderson, Teru Hideshima, Catrine Johansson, Udo Oppermann, Adam D. Durbin, Berkley Gryder, Javed Khan, xiaofeng zhang. Lysine demethylase 5A is required for MYC driven transcription in multiple myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB193.