HIF-PHD Inhibitor Roxadustat Promotes Erastin-Induced Ferroptosis in Lung Cancer Cells by Stabilizing HIF-2α and Targeting Hepcidin/FPN1 Axis

Abstract

Background: Ferroptosis has been conceptualized as a unique form of iron-dependent cell death, which holds the potential to treat drug-resistant cancers. Erastin-based therapy is expected to circumvent the shortcomings of apoptosis-mediated therapies, but a variety of tumors are insensitive to erastin. Here, we examined the effect of Roxadustat, a hypoxia inducible factor (HIF)-prolyl hydroxylase (PHD) inhibitor, on erastin-induced ferroptosis in lung cancer cells and the underlying mechanisms. Methods: Cytotoxicity of Roxadustat was investigated by lactate dehydrogenase (LDH) release assay in H1229 and A549 lung cancer cells. Ferroptosis-related activity of drug treatment was examined by the measurement of iron concentration, malondialdehyde (MDA), reactive oxygen species (ROS) and glutathione (GSH). Cell proliferation and migration abilities were analyzed by cell count kit (CCK)-8 and scratch assays. mRNA and protein expression levels were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. The ultrastructure of mitochondria was examined by transmission electron microscopy (TEM). The in vivo effect of Roxadustat on ferroptosis induction was evaluated in mouse xenograft model of lung cancer cells. Results: Roxadustat could disrupt cellular redox homeostasis, increase lipid peroxidation and induce cellular features of ferroptosis at sub-toxic concentration in H1229 and A549 cells. The application of Roxadustat augmented erastin-induced ferroptosis in vitro and in vivo. Roxadustat treatment stabilized HIF-2α protein, which in turn promoted hepcidin expression. The interaction between hepcidin and ferroportin 1 (FPN1) reduced FPN1 protein level by promoting FPN1 degradation. Silencing hepcidin or over-expressing FPN1 could attenuate the intracellular iron level increase and dampen the effect of Roxadustat on erastin-induced ferroptosis. Conclusions: These data demonstrated that Roxadustat enhances ferroptosis-inducing effect of erastin on lung cancer cells by regulating hepcidin/FPN1 axis through stabilizing HIF-2α, indicating the potential of Roxadustat as a ferroptosis-enhancing agent.