Synergistic mechanisms of ferroptosis in anaplastic thyroid cancer induced by dihydroartemisinin and sorafenib / 中华内分泌代谢杂志

ABSTRACT

Objective:To investigate the synergistic effects and molecular mechanisms of dihydroartemisinin(DHA) and sorafenib(SOR) in inducing ferroptosis in anaplastic thyroid cancer(ATC) cells.Methods:CCK-8 and flow cytometry assays were performed to detect the effects of DHA and SOR on the proliferation and ferroptosis of ATC cells(CAL-62). Real-time fluorescence quantitative PCR and Western blotting assays were performed to detect the expressions of ferroptosis-related genes glutathione peroxidase 4(GPX4), solute carrier family 7 member 11 gene(SCL7A11), lipoxygenase-15(LOX-15), and p53. The levels of iron death intermediate metabolites including lactate dehydrogenase(LDH), glutathione(GSH), malondialdehyde(MDA), ferrous ion(Fe 2+ ), nitric oxide(NO), and reactive oxygen species(ROS)were measured by corresponding assay kits. The corresponding inhibition of DHA and SOR on ATC in vivo was analyzed in a tumor model in nude mice. Results:Compared with the control group, DHA, SOR, and DHA+ SOR treatment significantly inhibited cell proliferation and apoptosis in a dose-dependent manner( P<0.001), with increased LDH, Fe 2+, MDA, and ROS contents and reduced GSH activity( P<0.001), which were promoted by ferrous sulfate(FeSO 4)and reversed by ferroptosis inhibitor-1. Compared with the control group and the drug monotherapy group, 15-LOX-2 and p53 expressions were upregulated in DHA+ SOR group while GPX4 and SCL7A11 expressions were decreased( P<0.001), without significant difference in 15-LOX-1 protein content. In addition, NO level was significantly increased in DHA+ SOR group( P<0.001). DHA and SOR inhibited tumor growth of ATC in vivo. Conclusion:DHA and SOR synergistically induced ferroptosis via upregulating the expression of 15-LOX-2 gene and inhibiting NO synthesis in ATC cells.