Extended Data Fig. 1: The lipid fraction of lipoproteins renders GPX4 dispensable in cancer cells.

a, b. Cellular uptake of DiI-labelled LDL (a) or HDL (b) in HeLa cells, quantified by median PE fluorescence intensity (left) and shown in representative histograms (right). Cells treated with DiI-LDL or DiI-HDL (blue) are compared to untreated controls (grey). c. Differential gene scores in HeLa cells cultured in lipoprotein-depleted serum (LPDS) with or without lipoprotein supplementation. Anti-ferroptotic genes and lipid metabolism genes are highlighted. d. Individual sgRNA scores (log₂) for GPX4 in the CRISPR screen in HeLa cells under indicated conditions. e, f. Immunoblot analysis of GPX4 in human (e) or mouse (f) isogenic cell lines with sgControl or GPX4/Gpx4 knockout (KO). GAPDH is included as loading control. g. Proliferation (log₂ doublings, 5 days) of indicated GPX4-deficient cell lines in vitro either untreated or supplemented with cholesterol (5 μg/mL), LDL (50 μg/mL), HDL (50 μg/mL) or Fer-1 (1 μM). h. Uncropped co-autoxidation of STY-BODIPY (1 μM) and liposomal egg phosphatidylcholine with cholesterol, initiated by DTUN (0.2 mM), and inhibited by 50 μg/mL LDL, HDL, reconstituted HDL with Tristearin (rHDL-TG(18:0)₃), or PMC (4 μM). i. Experimental approach to replace the non-polar lipid core of native lipoproteins. Native lipoproteins are first stripped of their non-polar core, and then reconstituted with tristearin (TG(18:0)₃). j. Proliferation (log₂ doublings, 5 days) of indicated GPX4-deficient cell lines in vitro either untreated or supplemented with cholesterol (5 μg/mL), combined native LDL and HDL (50 μg/mL), combined tristearin-reconstituted LDL and HDL (rLDL+rHDL, 50 μg/mL), or Fer-1 (1 μM). a, b, g, j: Bars represent mean ± s.d.; a, b, g, j: n = 3 biological replicates. Statistics by two-sided unpaired t-tests as indicated or compared to untreated cells (a, b, g, j). For gel source data, see Supplementary Fig. 1.

Source Data