Covalent inhibitors of EZH2: Design, synthesis and evaluation
Qiangsheng Zhang, Xinyi Chen, Xi Hu, Xianjie Duan, Guoquan Wan, Lu Li, Qiang Feng, Yiqian Zhang, Ningyu Wang, Luoting Yu
Abstract
The histone lysine methyltransferase EZH2 has been implicated as a key component in cancer development. Up to date, there are only a few EZH2 covalent inhibitors. In this study, a new series of 3-acrylamido-2-methyl-N-((2-oxo-1,2-dihydropyridin-3-yl) methyl) benzamide derivatives were designed, synthesized, and demonstrated to act as EZH2 covalent inhibitors, among which SKLB-03176 was the most potent compound. SAM competition experiments, mass spectrometry, and washing-out assays proved that SKLB-03176 could covalently bind to the SAM pocket of EZH2. Remarkably, SKLB-03176 exhibited weak activity against other targets, such as 5 histone methyltransferases and more than 30 kinases. Besides, it could inhibit the activity of a variety of EZH2 mutants and significantly inhibit the expression of H3K27Me3 in cells. Furthermore, SKLB-03176 showed no cytotoxicity to normal cells. Our data suggested that SKLB-03176 could be used as a promising lead compound for the development of new EZH2 covalent inhibitors and a valuable chemical tool to study the biological functions of EZH2 or PRC2.