biostudies-literatureMao CNCI NIH HHS586-590https://www.ebi.ac.uk/biostudies/studies/S-EPMC8895686biostudies-literatureUnknown593(7860)Ferroptosis, a form of regulated cell death that is induced by excessive lipid peroxidation, is a key tumour suppression mechanism^1-4. Glutathione peroxidase 4 (GPX4)^5,6 and ferroptosis suppressor protein 1 (FSP1)^7,8 constitute two major ferroptosis defence systems. Here we show that treatment of cancer cells with GPX4 inhibitors results in acute depletion of N-carbamoyl-L-aspartate, a pyrimidine biosynthesis intermediate, with concomitant accumulation of uridine. Supplementation with dihydroorotate or orotate-the substrate and product of dihydroorotate dehydrogenase (DHODH)-attenuates or potentiates ferroptosis induced by inhibition of GPX4, respectively, and these effects are particularly pronounced in cancer cells with low expression of GPX4 (GPX4<sup>loNatureDHODH-mediated ferroptosis defence is a targetable vulnerability in cancer.PMC8895686P50 CA070907P30 CA016672U54 CA224065R01 CA247992R01 CA244144R01 CA181196R01 CA190370Gan BLei GLee HFang BYan YOlszewski KLiu XPoyurovsky MVMao CZhang YWu SKoppula PZhuang LfalseDHODH-mediated ferroptosis defence is a targetable vulnerability in cancer.Ferroptosis, a form of regulated cell death that is induced by excessive lipid peroxidation, is a key tumour suppression mechanism^1-4. Glutathione peroxidase 4 (GPX4)^5,6 and ferroptosis suppressor protein 1 (FSP1)^7,8 constitute two major ferroptosis defence systems. Here we show that treatment of cancer cells with GPX4 inhibitors results in acute depletion of N-carbamoyl-L-aspartate, a pyrimidine biosynthesis intermediate, with concomitant accumulation of uridine. Supplementation with dihydroorotate or orotate-the substrate and product of dihydroorotate dehydrogenase (DHODH)-attenuates or potentiates ferroptosis induced by inhibition of GPX4, respectively, and these effects are particularly pronounced in cancer cells with low expression of GPX4 (GPX4<sup>lo2021-01-01T00:00:00Z2021 May2026-06-03T10:22:35.557Z2025-02-18T23:36:42.878ZS-EPMC88956863398103810.1038/s41586-021-03539-7