miR-4537 curtails ferroptosis by targeting MIOX in renal cell carcinoma

Ferroptosis, an iron-dependent mode of cell death, has gained prominence for its critical role in the advancement of various cancers, notably clear cell renal carcinoma (ccRCC). The intricacies of ferroptosis’s involvement in ccRCC, however, remain largely undefined. This study aimed to dissect the contribution of ferroptosis to ccRCC by examining differentially expressed genes (DEGs) identified within the TCGA ccRCC database and ferroptosis driver genes catalogued in the FerrDb database (dedicates to ferroptosis regulators and ferroptosis-disease associations). We employed 786-O and ACHN ccRCC cell lines, alongside HK2 (human kidey-2) cells and HKC (human kidney cells), to confirm the expression of 9 shared genes. Among these, MIOX (myo-inositol oxygenase) emerged as significantly downregulated in ccRCC cells compared to HK2 and HKC cells. Subsequent survival analysis illuminated a positive correlation between MIOX expression and improved patient survival, underscoring its prognostic significance. Further investigations into MIOX regulation identified four miRNAs via TargetScan predictions, with miR-4537 significantly upregulated in ccRCC cell lines. Functional assays involving miR-4537 mimics and inhibitors, combined with ferroptosis inducers and inhibitors, elucidated its impact on ccRCC cell growth and ferroptosis modulation. The results revealed that miR-4537 expression was diminished following ferroptosis induction, and the miR-4537 inhibitor markedly curbing ccRCC cell proliferation by fostering ferroptosis, while the mimic exerted opposite effects. Mechanistically, miR-4537 targets the 3′-UTR of MIOX to manipulate its expression, ultimately inhibiting ferroptosis in ccRCC cells. Our research indicated that miR-4537 restrained ferroptosis by regulating MIOX in ccRCC, offering novel insights into the mechanisms of ferroptosis in cancer biology and highlighting latent therapeutic avenues for cancer treatment through ferroptosis modulation.