CYP24A1 Binding to FUS Maintains Tumor Properties by Regulating the miR-200c/ZEB1/EMT Axis

The active vitamin D-degrading enzyme (CYP24A1) is commonly overexpressed in various types of cancer, which is associated with poor prognosis in cancer patients. Recent studies highlight the antagonism of CYP24A1 toward the anticancer role of active vitamin D. However, the impact of CYP24A1 on tumorigenesis and its underlying mechanisms largely remains unexplored. This study also found that high CYP24A1 mRNA expressions were associated with poor prognosis in ovarian cancer and lung adenocarcinoma (LUAD) patients. Moreover, we demonstrated that the overexpression of CYP24A1 accelerated the proliferation, migration, and invasion of ovarian cancer and LUAD cancer cells in vitro. Furthermore, knockdown of CYP24A1 displayed an anticancer effector both in vitro and in vivo. Mechanically, 87-297 amino acid motif of CYP24A1 bound specifically to FUS protein, consequentially reducing FUS affinity for miR-200c. Considering FUS promotes gene silencing by binding to microRNA targets, a decrease in miR-200c levels led to a notable activation of its target ZEB1, resulting in the promotion of the epithelial-mesenchymal transition (EMT) process. In conclusion, FUS binding specifically by CYP24A1 impaired miR-200c-mediated ZEB1 silencing, thereby augmenting EMT progression and tumorigenesis. These findings elucidate a fundamental mechanism by which CYP24A1 operates as an oncogene, offering potential targets for therapeutic interventions in cancer treatment.