Shen Zhihang, Yang Xiaozhi, Seabra Gustavo, Xu Xueyong, Dong Jiawei, Brant Jason Orr, Zhou Wei, Guan Juan, Jiang Wen, Li Chenglong
Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, Florida 32611-7011, United States.
Department of Biological Sciences, College of Medicine, Purdue University, West Lafayette, Indiana 47907, United States.
ACS Chem Biol. 2025 Jun 20;20(6):1333-1346. doi: 10.1021/acschembio.5c00160. Epub 2025 May 29.
Protein arginine methyltransferase 5 (PRMT5), which uniquely binds to 5'-methylthioadenosine (MTA) among the PRMT family, is emerging as an attractive epigenetic target for 5'-methylthioadenosine phosphorylase (MTAP)-deleted cancer treatments. Here, we report the discovery of a novel inhibitor 16-19F, which is a potent binder to the PRMT5•MTA, PRMT5•SAH, and PRMT5•SAM complexes and selectively inhibited MTAP-deleted cancer cell growth. Based on transcriptome analysis, we found that kinetochore metaphase signaling and cell cycle control of the chromosomal replication pathway were downregulated after 16-19F treatment in the MDA-MB-231 TNBC cell line. Additionally, we identified a new PRMT5 substrate, MCM7, an important component of DNA helicase, and figured out the potential methylation site Arg219 by site-directed mutagenesis and computational analysis. Moreover, we showed that 16-19F treatment regulated MCM7 localization, which is involved through liquid-liquid phase separation mechanisms, including the formation of stress granules. Together, we discovered a potential novel drug candidate and revealed an unknown mechanism in which PRMT5 methylation altered MCM7 localization by modulating stress granule formation.
蛋白质精氨酸甲基转移酶5（PRMT5）在PRMT家族中能独特地与5'-甲硫腺苷（MTA）结合，正成为针对5'-甲硫腺苷磷酸化酶（MTAP）缺失癌症治疗的一个有吸引力的表观遗传靶点。在此，我们报告了一种新型抑制剂16-19F的发现，它是PRMT5•MTA、PRMT5•SAH和PRMT5•SAM复合物的强效结合剂，并能选择性抑制MTAP缺失癌细胞的生长。基于转录组分析，我们发现在MDA-MB-231三阴性乳腺癌细胞系中，用16-19F处理后，动粒中期信号传导和染色体复制途径的细胞周期控制被下调。此外，我们鉴定出一种新的PRMT5底物MCM7，它是DNA解旋酶的一个重要组成部分，并通过定点诱变和计算分析确定了潜在的甲基化位点Arg219。而且，我们表明16-19F处理调节了MCM7的定位，这是通过液-液相分离机制实现的，包括应激颗粒的形成。总之，我们发现了一种潜在的新型候选药物，并揭示了一种未知机制，即PRMT5甲基化通过调节应激颗粒形成改变了MCM7的定位。
