The role of metabolism in tumor immune evasion: Novel approaches to improve immunotherapy
The tumor microenvironment exhibits altered metabolic properties as a consequence of the needs of tumor cells, the natural selection of the most adapted clones, and the selfish relationship with other cell types. Beyond its role in supporting uncontrolled tumor growth, through energy and building materials obtention, metabolism is a key element controlling tumor immune evasion. Immunotherapy has revolutionized the treatment of cancer, being the first line of treatment for multiple types of malignancies. However, many patients either do not benefit from immunotherapy or eventually relapse. In this review we overview the immunoediting process with a focus on the metabolism-related elements that are responsible for increased immune evasion, either through reduced immunogenicity or increased resistance of tumor cells to the apoptotic action of immune cells. Finally, we describe the main molecules to modulate these immune evasion processes through the control of the metabolic microenvironment as well as their clinical developmental status ; Work in the authors' laboratories was supported by "Instituto de Salud Carlos III" (ISCIII) PI19/01652 grant, Ministry of Science and Innovation RTC2017-6502-1 INmunoSIGHT and European Union's Horizon 2020 research and innovation programme, CLARIFY 875160 grant, to M.P. A.C.-B. received a Spanish Lung Cancer Group (SLCG) grant and is supported by a ISCIII-"Sara Borrell" contract CD19/00170. M.C. is supported by PEJD-2019-PRE/BMD-17006 contract granted to A.C.-B. R.L.-B. was supported by PEJ16/MED/AI-1972 and PEJD-2018-PRE/SAL-8641 from European Social Fund and Comunidad de Madrid, both granted to M.P