Discovery of a First-in-Class Degrader for the Lipid Kinase PIKfyve
Chungen Li, Yuanyuan Qiao, Xia Jiang, Lianchao Liu, Yang Zheng, Yudi Qiu, Caleb Cheng, Fengtao Zhou, Yang Zhou, Weixue Huang, Xiaomei Ren, Yuzhuo Wang, Zhen Wang, Arul M. Chinnaiyan, Ke Ding
Abstract
High Resolution Image Download MS PowerPoint Slide The phosphoinositide kinase PIKfyve has emerged as a new potential therapeutic target in various cancers. However, limited clinical progress has been achieved with PIKfyve inhibitors. Here, we report the discovery of a first-in-class PIKfyve degrader 12d (PIK5-12d) by employing the proteolysis-targeting chimera approach. PIK5-12d potently degraded PIKfyve protein with a DC 50 value of 1.48 nM and a D max value of 97.7% in prostate cancer VCaP cells. Mechanistic studies revealed that it selectively induced PIKfyve degradation in a VHL- and proteasome-dependent manner. PIKfyve degradation by PIK5-12d caused massive cytoplasmic vacuolization and blocked autophagic flux in multiple prostate cancer cell lines. Importantly, PIK5-12d was more effective in suppressing the growth of prostate cancer cells than the parent inhibitor and exerted prolonged inhibition of downstream signaling. Further, intraperitoneal administration of PIK5-12d exhibited potent PIKfyve degradation and suppressed tumor proliferation in vivo. Overall, PIK5-12d is a valuable chemical tool for exploring PIKfyve-based targeted therapy.