Fig. 2: SPT6 as a regulator of genomic stability in GSCs.
a Representative immunoblot analysis of SPT6, GFAP and SOX2 expression in GSCs and DGCs in GBM01, GBM02 and GBM03 lines. b Viability assay of GSCs (GBM01, GBM02) transfected with siCON or siRNAs targeting siSPT6 (siSPT6-34; siSPT6-35; siSPT6-36. Data are presented as mean values ± s.d. ****p < 0.0001; two-way ANOVA analysis with Sidak’s multiple comparisons test. c Viability assay of matched GSCs and DGCs (GBM01; GBM02) transfected with siCON or siSPT6-p. Data are presented as mean values ± s.d and normalized to siCON. GBM01: ***p = 0.005 (1 day), ****p < 0.0001 (day 2, 3, 4), ***p = 0.0001 (day 5); GBM02: non-significant p = 0.866 and p = 0.192 (day 1, 2, respectively), ****p < 0.0001 (3, 4, 5 days); two-way ANOVA and Sidak’s multiple comparisons test. (d) Representative extreme limiting dilution assay (ELDA) of GSCs (GBM01 and GBM02) transfected with siCON or siSPT6-p. Respective p-values (GBM01 p = 1.57E-14; GBM02 p = 1.94E-16 by ELDA analysis program) are listed in a table summary. e Representative immunoblot analysis of SPT6, GFAP, and SOX2 expression in GSCs transfected with siCON or siSPT6-p undergoing serum-(FBS)-induced differentiation. (f) Kaplan–Meier survival curves of mice implanted with GBM01 GSCs with silenced SPT6 (shSPT6-1 and shSPT6-2) compared to control (shLuc). n = 6 mice in each arm. **p = 0.0041; ***p = 0.0005; Log-rank/Mantel-Cox test. MS median survival, ND non-determined. g Representative immunoblot validation of SPT6 knockdown efficiency in GSCs used in (f). h Spearman correlation analysis of SPT6 expression and stem cell transcriptional signature using the Suva data set28. rs: −0.281, p-value < 2.2e-16. X-axis: positive values upregulated after SPT6 loss. Y-axis: positive values upregulated in GSCs cells. Color indicates the number of genes in each region. The black trend line is calculated as a smoothed average along the X-axis where the shaded region indicates standard error. N = 3 biologically independent experiments in (a–e), (g). Loading control: α-Tubulin in (a), (e), (g). Source data are provided as a Source data file.
