Abstract
Inactivation of p53 by mutations commonly occurs in human cancer. The mutated p53 proteins may escape proteolytic degradation and exhibit high expression in tumors and acquire gain-of-function activity that promotes tumor progression and chemo-resistance. Therefore, selectively targeting of the gain-of-function p53 mutants may serve as a promising therapeutic strategy for cancer prevention and treatment. In this study, we identified cabozantinib, a multikinase inhibitor currently used in the clinical treatment of several types of cancer, as a selective inducer of proteasomal degradation of the p53-Y220C mutant. We demonstrate that cabozantinib disrupts the interaction between p53Y220C and USP7, a deubiquitylating enzyme, resulting in the dissociation of p53Y220C protein from its binding with USP7 and subsequent ubiquitination and degradation mediated by CHIP (the carboxyl terminal of Hsp70-interacting protein). We also show that cabozantinib displays preferential cytotoxicity to p53Y220C-harboring cancer cells both in vitro and in vivo. This study demonstrates a novel, p53-Y220C mutant-targeted anticancer action and mechanism for cabozantinib and provides the rationale for use of this drug in the treatment of cancers that carry the p53-Y220C mutation.