Protocadherin 17 weakens the lenvatinib resistance of liver cancer through inducing ferroptosis

Lenvatinib has been employed in the treatment of advanced liver cancer; however, its clinical application is significantly impeded by frequent drug resistance. Recent studies have revealed that lenvatinib treatment triggers ferroptosis in liver cancer cells, providing a novel approach to addressing lenvatinib resistance. In this study, we initially validated the induction of ferroptosis by lenvatinib in liver cancer cells. Remarkably, protocadherin 17 (PCDH17), an adhesion-related protein, was found to be down-regulated in liver cancer, and overexpression of PCDH17 could induce ferroptosis in liver cancer cells. Importantly, silencing PCDH17 inhibited the impact of lenvatinib on liver cancer cell ferroptosis, while overexpression of PCDH17 had the opposite effect. These findings were further confirmed using a xenograft tumor model in BALB/c nude mice. Additionally, lenvatinib-resistant (LR) liver cancer cells were generated for additional validation purposes. It was observed that LR-liver cancer cells lost their susceptibility to ferroptosis induction by lenvatinib; however, overexpression of PCDH17 reactivated their sensitivity to ferroptosis. Corresponding results were also verified in BALB/c nude mice models. In conclusion, these results suggest that as a novel regulator of ferroptosis, PCDH17 can alleviate lenvatinib resistance and potentially enhance the therapeutic efficacy of lenvatinib in treating liver cancer.