Abstract

BACKGROUND Cisplatin (DDP) is the first-in-class drug for advanced and non-targetable non-small-cell lung cancer (NSCLC). A recent study indicated that DDP could slightly induce non-apoptotic cell death ferroptosis, and the cytotoxicity was promoted by ferroptosis inducer. The agents enhancing the ferroptosis may therefore increase the anticancer effect of DDP. Several lines of evidence supporting the use of phytochemicals in NSCLC therapy. Ginkgetin, a bioflavonoid derived from Ginkgo biloba leaves, showed anticancer effects on NSCLC by triggering autophagy. Ferroptosis can be triggered by autophagy, which regulates redox homeostasis. Thus, we aimed to elucidate the possible role of ferroptosis involved in the synergistic effect of ginkgetin and DDP in cancer therapy. METHODS The promotion of DDP-induced anticancer effects by ginkgetin was examined via a cytotoxicity assay and western blot. Ferroptosis triggered by ginkgetin in DDP-treated NSCLC was observed via a lipid peroxidation assay, a labile iron pool assay, western blot, and qPCR. With ferroptosis blocking, the contribution of ferroptosis to ginkgetin + DDP-induced cytotoxicity, the Nrf2/HO-1 axis, and apoptosis were determined via a luciferase assay, immunostaining, chromatin immunoprecipitation (CHIP), and flow cytometry. The role of ferroptosis in ginkgetin + DDP-treated NSCLC cells was illustrated by the application of ferroptosis inhibitors, which was further demonstrated in a xenograft nude mouse model. RESULTS