miR-15a induces prostate cancer cell ferroptosis via GPX4. (A) Intracellular ferrous iron levels were determined via the iron assay in LNCAP cells transfected with miR-15a mimics, si-GPX4 or NCs. (B) Lipid ROS levels were measured via flow cytometric analysis using C11-BODIPY in LNCAP cells transfected with miR-15a mimics, si-GPX4 or NCs. (C) MMP was detected via JC-1 staining and flow cytometric analysis in LNCAP cells transfected with miR-15a mimics, si-GPX4 or NCs. (D) MDA levels were measured in LNCAP cells transfected with miR-15a mimics, si-GPX4 or NCs. **P<0.01 vs. control group. miR, microRNA; GPX4, glutathione peroxidase 4; si, small interfering; NC, negative control; ROS, reactive oxygen species; MMP, mitochondrial membrane potential; MDA, malondialdehyde.