Abstract 4417: Development of biochemical screening assays to facilitate drug discovery in RNA m6A modification regulators

Abstract Over the recent years, knowledge of RNA modifications and their regulation has expanded extensively, providing novel insights and strategies to explore potential therapeutics for pathogenesis of various diseases, including cancer. Several chemical modifications in RNA have been identified so far, among these N6-methyladenosine (m6A) modification is the most abundant and well-studied epitranscriptomic marker found in mRNA and long noncoding RNA. Abnormal m6A expression is proven to be associated with tumorigenesis, cancer stemness and drug resistance of cancers. Methylation in 6-Adenosin of RNA is a dynamic and reversible process tightly regulated by its writer, m6A methyltransferase complex and erasers, FTO and ALKBH5. m6A methyltransferase complex contains METTL3-METTL14-WTAP as core components. METTL3 is the catalytic component, which is activated by heterodimer formation with METTL14. High METTL3 expression is found in several cancers such as breast, lung, liver, gastric, colorectal, AML and a METTL3 catalytic inhibitor is found to delay AML progression in mouse models. Protein that binds RNA m6A modification to execute it signaling are known as m6A readers. Readers are categorized into three main classes, YTH domain proteins, IGF2 mRNA-binding proteins and heterogeneous nuclear ribonucleoproteins. YTH family readers are found to have oncogenic roles in several cancers including AML, breast, lung, CRC and glioblastoma. Recent studies suggest inhibition of m6A binding of individual YTH family proteins is a promising therapeutic strategy however, potent inhibitors are yet to be identified. This poster summarizes current assays we have developed to facilitate cancer therapeutic discovery in m6A related protein targets. We present development and validation of an assay suitable identify in METTL3 catalytic inhibitors using our proprietary hotspot technology. We also show development of HTRF based biochemical assays for all five YTH family protein YTHDF1-3 and YTHDC1-2, to screen for molecules that disrupt protein-m6A interaction. We further study the selectivity of an FDA approved drug Tegaserod, a reported YTHDF1 inhibitor by a structure based virtual screening, between YTH family proteins. Citation Format: Safnas F. AbdulSalam, Sung Won Oh, Brenna P. Lee, Joseph J. Ferry, John R. Ries, Kurumi Y. Horiuchi. Development of biochemical screening assays to facilitate drug discovery in RNA m6A modification regulators abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 4417.