Fig. 2: Methionine-derived SAM accounts for cystine deprivation-induced ferroptosis.

A, B The cells were cultured as indicated for 8–24 h. A The lipid ROS levels were determined (AML12/MIHA for 24 h, MEF for 8 h, HT1080 for 10 h). B The cell death levels were quantified (AML12/MIHA for 30 h, HT1080 for 14 h). C HT1080 cells were cultured as indicated for 10 h. The metabolites levels were measured by UHPLC-HRMS. Metabolites with FC ≥ 2 and p < 0.05 were considered as hits. Blue color indicated the decreased metabolites; red color indicated the increased ones. D–J The cells were simultaneously treated as indicated for 8–30 h. D, G, I The lipid ROS levels were determined (MEF for 8 h, HT1080 for 10 h, OS-RC-2 for 14 h, HL-1 for 24 h). F The mRNA levels of PTGS2 were determined at the 8 h. E, H, J The cell death levels were determined (MEF for 12 h, HT1080 for 14 h, OS-RC-2 for 18 h, HL-1 for 30 h). K, L HT1080 was transfected with non-targeting siRNA (siControl) or targeting MAT2A siRNA for 48 h, and then cultured as indicated for another 10–14 h. K The lipid ROS levels were determined at the 10 h. L The cell death levels were quantified at the 14 h. M, N HT1080 cells were transfected without or with CHAC1 plasmid for 48 h, then cultured as indicated for another 10–14 h. M The levels of total GSH and CHAC1 proteins were determined at the 10 h. N The cell death levels were quantified at the 14 h. CC, 0.4 mM; Met, 0.4 mM; SAM, 0.4 mM; SAH, 0.4 mM; Hcy, 0.4 mM; Cta, 0.4 mM; Cys, 0.4 mM; Erastin, 2 μM; IKE, 2 μM; FIDAS-5, 5 μM. n = 3 (A–M) or n = 5 (N) biological replicates, data were represented as mean ± SD with p values determined by unpaired two-tailed t test (C), one-way (A, B, D–J, M, N) or two-way (K, L) ANOVA test. Source data are provided as a Source Data file.