miR-612 Enhances RSL3-Induced Ferroptosis of Hepatocellular Carcinoma Cells via Mevalonate Pathway.

BACKGROUND: MicroRNA-612 (miR-612) has been proven to suppress the formation of invadopodia and inhibit hepatocellular carcinoma (HCC) metastasis by hydroxyacyl-CoA dehydrogenase alpha subunit (HADHA)-mediated lipid reprogramming. However, its biological roles in HCC cell ferroptosis remain unclear.

METHODS AND RESULTS: In this study, we found that HCC cells with high metastatic potential were more resistant to ferroptosis, indicating that ferroptosis is related to HCC metastasis. The levels of lipid reactive oxygen species (ROS) were found to be much lower in HCC cells with high metastatic potential by flow cytometry (FCM). We used HCC cells with miR-612 overexpression/knockout and HADHA overexpression/knockdown to test cell viability after stimulation with RSL3. HCC cells overexpressing miR-612 were more sensitive to ferroptosis, and miR-612 could increase lipid ROS levels. Furthermore, colony formation assays and Transwell assays showed that miR-612 could inhibit the proliferation and metastasis of HCC cells by promoting ferroptosis. We next confirmed that miR-612 influenced HCC cell ferroptosis by regulating HADHA. HADHA could upregulate the expression of key enzymes in the mevalonate (MVA) pathway. HADHA overexpression upregulated the expression of CoQ10 and decreased polyunsaturated fatty acid (PUFA) levels and lipid peroxide abundance. miR-612 also suppressed HCC cell proliferation and metastasis by enhancing RSL3- and lovastatin-induced ferroptosis in vivo.

CONCLUSION: Overall, miR-612 promotes ferroptosis in HCC cells and affects HCC proliferation and metastasis by downregulating CoQ10 and increasing cellular PUFA levels and lipid peroxides via the HADHA-mediated MVA pathway.