Broadening horizons: the role of ferroptosis in cancer

The discovery of regulated cell death processes has enabled advances in cancer treatment. In the past decade, ferroptosis, an iron-dependent form of regulated cell death driven by excessive lipid peroxidation, has been implicated in the development and therapeutic responses of various types of tumours. Experimental reagents (such as erastin and RSL3), approved drugs (for example, sorafenib, sulfasalazine, statins and artemisinin), ionizing radiation and cytokines (such as IFNγ and TGFβ1) can induce ferroptosis and suppress tumour growth. However, ferroptotic damage can trigger inflammation-associated immunosuppression in the tumour microenvironment, thus favouring tumour growth. The extent to which ferroptosis affects tumour biology is unclear, although several studies have found important correlations between mutations in cancer-relevant genes (for example, RAS and TP53 ), in genes encoding proteins involved in stress response pathways (such as NFE2L2 signalling, autophagy and hypoxia) and the epithelial-to-mesenchymal transition, and responses to treatments that activate ferroptosis. Herein, we present the key molecular mechanisms of ferroptosis, describe the crosstalk between ferroptosis and tumour-associated signalling pathways, and discuss the potential applications of ferroptosis in the context of systemic therapy, radiotherapy and immunotherapy. Ferroptosis is an iron-dependent form of regulated cell death driven by excessive lipid peroxidation. Pharmacological agents, ionizing radiation and cytokines can induce ferroptosis and thus suppress tumour growth, but ferroptosis can also trigger inflammation-associated immunosuppression. The authors describe the key molecular mechanisms of ferroptosis, including crosstalk with tumour-associated signalling pathways, and discuss potential therapeutic applications of ferroptosis. Key points Ferroptosis is a form of regulated cell death that mainly relies on iron-mediated oxidative damage and subsequent cell membrane damage. Ferroptosis can be initiated through two major pathways: the extrinsic or transporter-dependent pathway, and the intrinsic or enzyme-regulated pathway. The increase in iron accumulation, free radical production, fatty acid supply and lipid peroxidation by dedicated enzymes is critical for the induction of ferroptosis. Multiple oxidative and antioxidant systems, acting together with the autophagy and membrane repair machinery, shape the process of lipid peroxidation during ferroptosis. In t