Abstract 676: Substrate specificity and inhibitors of histone lysine HMTase NSD1, NSD2/MMSET/WHSC1, and NSD3/WHSC1L1.

Abstract

Abstract The nuclear receptor binding SET domain proteins (NSDs) is a family of three histone-lysine N-methyltransferases, NSD1, NSD2/MMSET/WHSC1, and NSD3/WHSC1L1. The NSDs are oncogenes. The amplification of NSD1 has been reported in multiple myeloma, lung cancer, neuroblastomas and glioblastomas. The amplification of either NSD1 or NSD2 triggers the cellular transformation to cancer formation. NSD2 is associated with tumor aggressiveness or prognosis in most types of cancers including prostate cancer and multiple myeloma and is overexpressed in at least 15 different cancers. Increased NSD2 activity was reported in tumor proliferation in glioblastoma multiforms and myeloma, resulting in aberrantly high global levels of H3K36me2. NSD3 is involved in lung cancer and found amplified in breast cancer cell lines and primary breast carcinomas. The abnormal NSD1-NUP98 and NSD3-NUP98 fusions increase H3K36 methylation, leading to acute myeloid leukemia. Although the NSD proteins are instrumental in the development of numerous cancers, their mechanisms of action in this context remain unclear. However, it appears that consequently increased H3K36 methylation by deregulated NSDs concomitant with decreased H3K27 methylation is perhaps one of the underlying mechanisms that alter gene expression profiles. In this study, we defined the molecular determinants of the recognition of histone marks by the NSDs to provide medicinal chemistry insights into the design of selective and specific NSDs inhibitors. Our data highlights the catalytic versatility of NSD1, NSD2, and NSD3 in regulating the epigenome. Our results propose the first molecular models of the binding of 6-mer peptides H3K4 a.a.1-7; H3K9 a.a.5-11; H3K27 a.a.23-29; H3K36 a.a.32-38; H3K79 a.a.75-81; H4K20 a.a.16-22 with the catalytic domain of the NSDs. Exploiting this data, we derived a virtual ligand screening strategy to identify inhibitors targeting NSD1, NSD2 and NSD3. In vitro, using recombinant NSDs-SET purified enzyme, we performed H3K36me1 inhibitory assays with the top candidates. Here for the first time, we report the discovery of a small subset of NSD inhibitors (namely LEM-xx) that do not violate the empirical Lipinski's rule of five, have a wcLogP < 3 and a total polar surface area <90 A**2. Citation Format: Eric Di Luccio, Masayo Morishita. Substrate specificity and inhibitors of histone lysine HMTase NSD1, NSD2/MMSET/WHSC1, and NSD3/WHSC1L1. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 676. doi:10.1158/1538-7445.AM2013-676 Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.