USP36 inhibits ferroptosis of melanoma cells by stabilizing APEX1
摘要
Cutaneous melanoma is an aggressive skin cancer characterized by high rates of recurrence and mortality, especially in its advanced stages. Ferroptosis, a distinct form of programmed cell death, has emerged as a promising therapeutic strategy for cancer. Nevertheless, the regulatory mechanisms underlying ferroptosis in melanoma remain poorly defined. In this study, we aimed to elucidate the role of USP36, a deubiquitinating enzyme that removes ubiquitin from substrate proteins, in the ferroptosis of melanoma cells. Using A375 and SK-MEL-28 melanoma cells treated with the ferroptosis inducer erastin, we analyzed USP36 expression and evaluated its functional role through both overexpression and knockdown experiments. Co-immunoprecipitation and ubiquitination assays demonstrated that USP36 stabilizes APEX1 through the cleavage of its K48-linked ubiquitin chains. We further employed USP36-deficient xenograft models to assess tumor growth and ferroptosis sensitivity. Our results indicate that erastin downregulates USP36, whereas overexpression of USP36 suppresses ferroptosis. Importantly, knockdown of APEX1 abolished the anti-ferroptotic effect of USP36. In addition, USP36-deficient tumors exhibited reduced proliferation and enhanced ferroptosis. Collectively, these findings establish USP36 as an oncogene in melanoma that inhibits ferroptosis through stabilization of APEX1. Therefore, targeting the USP36-APEX1 axis may represent a novel therapeutic approach for melanoma treatment.
Graphical Abstract