Development of a Highly Selective Ferroptosis Inducer Targeting GPX4 with 2-Ethynylthiazole-4-carboxamide as Electrophilic Warhead
Shi‐Hong Gu, Guanyu Yang, Hongyuan Bian, Fan Yang, Yajing Zhang, Yanhong Huang, Rui Su, Huilian Zhang, Xiuchun Zhao, Jin Liu, Shuheng Huang, Ling Huang, Benxin Hou, Yong Rao, Congjun Xu
Abstract
A highly selective ferroptosis inducer with drug-like properties can significantly advance the research on inducing ferroptosis for anticancer treatment. We previously reported a highly active GPX4 inhibitor 26a, but its activity and stability need further improvement. In this work, a novel GPX4 inhibitor ( R )-9i with more potent cytotoxicity (IC 50 = 0.0003 μM against HT1080) and ferroptosis selectivity (selectivity index = 24933) was gained via further electrophilic warhead screening and structure-based optimization. The cellular thermal shift assay (CETSA) indicated that ( R )-9i could stabilize GPX4 with a T m value of 6.2 °C. Furthermore, ( R )-9i showed strong binding affinity against GPX4 ( K D = 20.4 nM). More importantly, ( R )-9i has more favorable pharmacokinetic properties than 26a, which endowed ( R )-9i with potential in antitumor research and as a tool drug for further study of ferroptosis. Associated with these, ( R )-9i treatment significantly inhibited tumor growth in the xenograft tumor mouse model without detectable toxicity.