Extended Data Fig. 10: PRMT5 inhibitor sensitives cell to ferroptosis in vitro and in vivo.
From: PRMT5-mediated arginine methylation stabilizes GPX4 to suppress ferroptosis in cancer
a, Parental and PRMT5-deficient human tumor cells were treated with IKE and Fer-1. Lipid ROS levels were measured. b-d, Human tumor cells were pretreated with GSK3326595 followed by IKE and Fer-1 treatment. Lipid ROS (b), MDA (c) levels and cell viability (d) were measured. e, Depletion of FBW7 in human tumor cells and parental tumor cells were pretreated with GSK3326595 followed by treated with IKE or RSL3. Cell viability was measured. f-g, IB analysis and of cell lysates derived from MB49 (f) or C4-2 (g) implanted tumors in mice treated with GSK3326595 for 14 days. n = 5 mice per experimental group. h-l, C4-2 cells were subjected to mouse xenograft assays, When the tumor reached 50 mm3, the mice were assigned randomly into different treatment groups treat with RSL3 (100 mg/kg) combined with or without GSK3326595 (40 mg/kg), Tumor sizes were monitored (h) until the endpoint at day 30, and dissected tumors were weighed (i-j). Representative image (k) and statistical analysis (l) of IHC staining with the indicated antibodies of xenograft tumors from l. Scale bar, 100 μm. For a-e, data are mean ± s.d. of n = 3 biological replicates, P values were calculated using a two-tailed Student’s t-test. Data in f, h, j, l represent the mean ± s.e.m., n = 5 mice, P values were calculated using a two-tailed Student’s t-test. For k, P values were calculated using a log-rank test (two-tailed). m, By CRISPR–Cas9 screen of ferroptosis regulators, we identify MAT2A-induced GPX4 methylation as a new mechanism for ferroptosis resistance in cancer. In highly PRMT5-expressing cancers, GPX4 is methylated at R152 by PRMT5 to antagonize E3 ligase FBW7-regulated degradation, thereby promoting ferroptosis resistance. Targeting PRMT5 by GSK3326595 hinder GPX4 methylation, meanwhile, enhance GPX4 ubiquitination by Cullin1-FBW7 increasing cancer vulnerability during ferroptosis activation. All of the experiments, from a to e, were repeated at least twice independently, yielding identical outcomes.
