Metabolic determinants of cancer cell sensitivity to canonical ferroptosis inducers.

Publication Type Academic Article
Authors Soula M, Weber R, Zilka O, Alwaseem H, La K, Yen F, Molina H, Garcia-Bermudez J, Pratt D, Birsoy K
Journal Nat Chem Biol
Volume 16
Issue 12
Pagination 1351-1360
Date Published 08/10/2020
ISSN 1552-4469
Keywords Cystine, Ferroptosis, Gene Expression Regulation, Neoplastic, Phospholipid Hydroperoxide Glutathione Peroxidase, Tetrahydrofolate Dehydrogenase
Abstract Cancer cells rewire their metabolism and rely on endogenous antioxidants to mitigate lethal oxidative damage to lipids. However, the metabolic processes that modulate the response to lipid peroxidation are poorly defined. Using genetic screens, we compared metabolic genes essential for proliferation upon inhibition of cystine uptake or glutathione peroxidase-4 (GPX4). Interestingly, very few genes were commonly required under both conditions, suggesting that cystine limitation and GPX4 inhibition may impair proliferation via distinct mechanisms. Our screens also identify tetrahydrobiopterin (BH4) biosynthesis as an essential metabolic pathway upon GPX4 inhibition. Mechanistically, BH4 is a potent radical-trapping antioxidant that protects lipid membranes from autoxidation, alone and in synergy with vitamin E. Dihydrofolate reductase catalyzes the regeneration of BH4, and its inhibition by methotrexate synergizes with GPX4 inhibition. Altogether, our work identifies the mechanism by which BH4 acts as an endogenous antioxidant and provides a compendium of metabolic modifiers of lipid peroxidation.
DOI 10.1038/s41589-020-0613-y
PubMed ID 32778843
PubMed Central ID PMC8299533
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