Extended Data Fig. 6: GAG sulfation and xylose synthesis are essential for lipoprotein-mediated ferroptosis resistance in lymphoma cells.

a. Schematic showing that GAG sulfation depends on PAPSS1-derived 3′-phosphoadenylylsulfate and its Golgi import via SLC35B2. b. Individual sgRNA scores (log₂) for PAPSS1 in untreated and ML210-treated conditions (left) or in high and low DiI-LDL populations (right) of the Karpas299 CRISPR screens. c. Immunoblot of PAPSS1 in Karpas299 cells transduced with a sgControl or sgPAPSS1. GAPDH included as a loading control. d. Quantification of heparan sulfate (HS) in Karpas299 cells transduced with a sgControl or sgPAPSS1. e. Quantification of total sulfate per glycosaminoglycan disaccharide in Karpas299 cells transduced with a sgControl or sgPAPSS1. f. Proliferation (log₂ doublings, 5 days) of Karpas299 cells transduced with a sgControl or sgPAPSS1 under the indicated concentrations of ML162. g. Schematic showing UGDH-driven synthesis of UDP-GlcUA and its conversion by UXS1 into UDP-xylose, the initiating sugar of the GAG linker to proteoglycans. h. Individual sgRNA scores (log₂) for UXS1 in the presence and absence of ML210 (left), or in high and low DiI-LDL populations (right) of Karpas299 CRISPR screens. i. Sanger sequencing of UXS1 gene exon 9 in Karpas299 parental cells (WT) or transduced with sgUXS1. j. Quantification of total milligrams of HS per gram of protein in Karpas299 cells transduced with a sgControl or sgUXS1. k. Proliferation (log₂ doublings, 5 days) of Karpas299 cells transduced with a sgControl or sgUXS1 under the indicated concentrations of ML162. l. Cellular uptake of DiI-LDL in Karpas299 cells transduced with a sgControl, sgUGDH, sgPAPSS1 or sgUXS1, quantified by median PE fluorescence intensity. d-f, j-l, Bars represent mean ± s.d.; d-f, j-l, n = 3 biological replicates. Statistics by two-sided unpaired t-tests compared to sgControl cells (d-f, j-l). For gel source data, see Supplementary Fig. 1.

Source Data