Extended Data Fig. 1: LKB1 loss in the context of oncogenic KRAS mutations enhances serine and glycine biosynthesis in NSCLC.
a, Metabolite set enrichment analysis using metabolome in an isogenic pair of A549 cells. SGOC metabolism-related pathways are in pink. Dots are colored by enrichment FDR values. b, Volcano plot presenting metabolites whose levels are significantly changed in A549-EV cells compared with A549-LKB1 cells. Blue dots represent metabolite depletion (log2 < -1) and red dots represent metabolite accumulation (log2 > 1) in A549-EV cells. non-SGOC metabolism/folate-methionine cycle intermediates are labeled in grey. c, serine and glycine pool size in H460-EV and -LKB1 cells used for [U-13C]glucose labeling in Fig. 1f. d and e, 13C labeling in glycine in the same set of samples in Fig. 1f (H460 and A549 (d) and H1373 (e) cells). f, Effect of LKB1 on serine m + 2/m + 1 from [U-13C]serine labeling in H460-EV and -LKB1 or H1373-shGFP and -shLKB1. g, Abundance of LKB1 in isogenic pairs of KL NSCLC cells. Vinculin was used as a loading control. h and i, 13C labeling in serine (h) and glycine (i) in a panel of NSCLC cells with different oncogenotypes (K, KRAS mutants; KL, KRAS/LKB1 co-mutants; L, LKB1 mutants)(n = 3 per cell line) cultured with [U-13C]glucose for 6 hours. j, Abundance of LKB1 in EV-, WT LKB1- and KD LKB1-H460 cells. CPS1 was used as a marker for LKB1 activity as reported previously22 and Actin was used as a loading control. k, 13C labeling in serine in cells used in Fig. 1i and Supplementary Fig. 1l. l, 13C labeling in glycine in three isogenic pairs of cells cultured with [U-13C]serine for 2 hours. Data are the mean ± s.d. of three independent cultures. Statistical significance was assessed using a two-tailed t-test (c to f, k and l) and a one-way ANOVA (h and i) with the data from each oncogenotype as a group. Metabolomics analysis was done once. All other experiments were repeated three times or more.
