Supplementary Figure 1: GTP metabolism is reprogrammed in glioblastoma.

a, A schematic diagram of carbon flux of glucose to purine nucleotides. Red and white dots represents ¹³C and ¹²C, respectively. M denotes mass of the unlabeled metabolite. Above M+3 labeling of GTP or ATP are indicative of biosynthesized from the fed [U-¹³C]glucose. b, GTP pool size increases from neural stem cells (NSC) to its isogenic glioma stem cells (GSC). Data are presented as mean+s.d. n=3 biologically independent samples. c, Mass isotopomer analysis of nucleotides in the indicated cells. U87MG, LN229 and primary glia are cultured for 4 h with [U-¹³C]glucose. Data are presented as an average of 3 biologically independent samples. d, e, Metabolic flux analysis with [U-¹³C]glucose shows continuous ATP biosynthesis is utilized for NAD⁺ and SAM production in GBM, primary glia, NSC and GSC. Data are presented as an average of 3 biologically independent samples (d, left and e) and as mean+s.d., n=3 biologically independent samples (d, right). One-way ANOVA. f, Salvage purine nucleosides are more rapidly incorporated in primary glia than U87MG. The guanosine concentration in the medium was quantified by ion chromatography (IC)-MS. Data are presented as mean+s.d. n=3 biologically independent samples. Unpaired two-sided Student’s t-test. g, ¹⁵N-guanosine is incorporated into GTP in primary glia. Primary glia cells were treated with 1 μM [U-¹⁵N]-guanosine for 4 h and then cellular metabolite were analyzed by IC-MS. Data are presented as mean+s.d. n=3 biologically independent samples. h, Primary glia is more sensitive to 6-thioguanine (6-TG) than GBM cells. The indicated cells were treated with 6-TG and their cell viability were assessed by crystal violet assay. Data are presented as mean+s.d. n=3 biologically independent samples. Unpaired two-sided Student’s t-test. i, j, NSC utilizes more salvage GTP biosynthesis than GSC. NSC and GSC were incubated with [U-¹³C, ¹⁵N]-labeled glutamine for 24 h and cellular metabolites were analyzed by IC-MS. A schematic diagram of nitrogen flux from glutamine to GTP. Data are presented as an average of 3 biologically independent samples (i) and as mean+s.d., n=3 biologically independent samples (j). Unpaired two-sided Student’s t-test.