He Chen, Rudra Prasad Dutta, Zhizhong Li, Yue Zhong, Anqi Ma, Kwang-Su Park, Jithesh Kottur, Alison Park, Nicolas Babault, Ke Wang, Dandan Wang, Yan Xiong, H. Ümit Kaniskan, Minkui Luo, Samir Parekh, and Jian Jin
Journal of Medicinal Chemistry 2026
DOI: 10.1021/acs.jmedchem.5c02958
Dysregulated signaling of SET domain-containing protein 8 (SETD8) has been implicated in tumorigenesis, yet most SETD8 inhibitors exhibited limited cellular efficacy. Herein, we developed a potent and selective SETD8 covalent inhibitor, MS2928 (3), featuring a propiolamide covalent warhead. Compound 3 potently and selectively inhibited SETD8 methyltransferase activity. The covalent inhibition mechanism of 3 was confirmed by mass spectrometry and X-ray crystallography. Moreover, 3 significantly reduced the histone H4 lysine 20 monomethylation (H4K20me1) levels in cells and robustly inhibited the proliferation of SETD8-overexpressing multiple myeloma (MM) cell lines with no significant antiproliferative effect on SETD8-low expressing MM cells and normal cells. Importantly, 3 effectively inhibited tumor growth in vivo in two xenograft mouse models of SETD8-overexpressing MM cell lines. Collectively, our results establish 3 as a valuable chemical tool for exploring the biological functions of SETD8 and pave the way for further development of novel epigenetic therapies for MM.
