Ferroptosis is a form of cell death that is triggered by the presence of ferrous ions and is characterized by lipid peroxidation induced by these ions. The mechanism exhibits distinct morphological characteristics compared to apoptosis, autophagy, and necrosis. A notable aspect of ferroptosis is its ability to inhibit uncontrolled tumor replication and immortalization, especially in malignant, drug-resistant, and metastatic tumors. Additionally, immunotherapy, a novel therapeutic approach for tumors, has been found to have a reciprocal regulatory relationship with ferroptosis in the context of anti-tumor therapy. A comprehensive analysis of ferroptosis and immunotherapy in tumor therapy is presented in this paper, highlighting the potential for mutual adjuvant effects. Specifically, we discuss the mechanisms underlying ferroptosis and immunotherapy, emphasizing their ability to improve the tumor immune microenvironment and enhance immunotherapeutic effects. Furthermore, we investigate how immunotherapeutic factors may increase the sensitivity of tumor cells to ferroptosis. We aim to provide a prospective view of the promising value of combined ferroptosis and immunotherapy in anticancer therapy by elucidating the mutual regulatory network between each.
Graphical Abstract
Ferroptosis in the tumor microenvironment involves intricate crosstalk between tumor cells and immune cells. Through MHC recognition, CD8+T cells activate the JAK1/STAT1 pathway in tumor cells, impairing the function of System Xc and reducing GSH and GPX4 expression to promote tumor cell ferroptosis. Additionally, activation of the STAT1-IRF1-ACSL4 pathway could also promote ferroptosis. The blockade of the antioxidant pathway in tumor cells induces ferroptosis, and the released DAMPs could promote DCs maturation through the cGAMP-STING-TBK1 pathway, leading to antigen presentation that activates CD8+T cells. The release of DAMPs also induces the M1-type polarization of macrophages, which exerts an anti-tumor effect. The anti-tumor effects of CD8+T cells could also be enhanced by blocking inhibitory immune checkpoints such as PD-1, PD-L1, CTLA4, and LAG3. Abbreviations: ACSL4, acyl-CoA synthetase long-chain family member 4; BH4, tetrahydrobiopterin; cGAMP, cyclic GMP-AMP; CTLA4, cytotoxic T lymphocyte-associated antigen-4; DCs, dendritic cells; DHFR, dihydrofolate reductase; DHODH, dihydroorotate dehydrogenase; GPX4, glutathione peroxidase 4; GSH, glutathione; HIF-1α, Hypoxia-Inducible Factor-1α;IFN-γ, interferon-γ; IRF1, interferon regulatory factor 1;IRP1, iron regulatory protein 1; JAK 1, janus kinase; LAG3, lymphocyte activation gene 3; MHC, major histocompatibility complex; NRF2, nuclear factor erythroid-2-related factor 2; PD-1, programmed death protein -1; PD-L1, programmed death ligand 1; PUFA, polyunsaturated fatty acid; ROS, reative oxygen species; STAT1, signal transducer and activator of transcription 1; STING, stimulator of interferon genes; TBK1, TANK-binding kinase 1 TLR2, toll-like receptor 2. This diagram was drawn by Figdraw (www.figdraw.com).
