Fig. 5: OLIG2 inhibition blocks SOX2⁺ MB stem cell activation.

a Volcano plot comparing fold change (x-axis) and false discovery rate (y-axis) obtained from EdgeR analysis of the differentially expressed genes between IC₅₀ (189.2 nM) CT-179 or vehicle treatment of Ptch1^+/−;Trp53^−/− (PTCP53 304) mouse tumour cells for 6 days. b Relative fold change expression of select genes in vehicle and CT-179 treated cells from dataset shown in (a); n = 3 biological replicates, error bars denote mean ± SEM; two-tailed unpaired t-test; ns p ≥ 0.05, *p < 0.05, **p < 0.01. c, d Representative immunofluorescence (IF) images of endogenous SOX2, OLIG2, and EdU in early (c) or late (d) neoplastic lesions of mice sacrificed after 7 days of continuous EdU label in the presence of either vehicle (dH₂O) or CT-179 daily injections. Scale bar: 50 µM for 20X and 25 µM for 40X. e Quantification of the fraction of SOX2 ⁺ cells and of EdU incorporation in (c) relative to DAPI⁺ cells. n = 4 for CT-179, n = 3 for vehicle; error bars denote mean ± SEM; two-tailed unpaired t-test. unpaired t-test; *p < 0.05, ****p < 0.0001; p = 0.0240 (SOX2⁺), p = 0.0081 (OLIG2⁺/EdU⁺). f Quantification of the fraction of SOX2⁺ or SOX2⁺ and OLIG2⁺ cells that have incorporated EdU in (d). n = 3 for CT-179, n = 3 for vehicle; error bars denote mean ± SEM; two-tailed unpaired t-test; **p < 0.01, ***p < 0.001; p = 0.0006 (EdU⁺), p < 0.0001 (EdU⁺). g Representative immunofluorescence (IF) images of endogenous SOX2, EdU, and BrdU in early neoplastic lesions in mice sacrificed after 4 days of EdU label followed by an 8-day chase period of which 7 days were treatment with either vehicle (dH₂O) or CT-179 by daily IP injections, followed by a single BrdU pulse. Scale bar: 50 µM for 20X and 25µM for 40X. SOX2⁺/EdU⁺ cells are indicated with white arrows in the 40x image, while the yellow arrow indicates a triple positive cell (SOX2⁺/EdU⁺/BrdU⁺). h Quantification of the fraction of SOX2⁺ cells that have incorporated EdU or BrdU as represented in (g). For the quantification, 8 independent lesions were evaluated from 3 mouse brains for each treatment condition (vehicle or CT-179); error bars denote mean ± SEM; two-tailed unpaired t-test; ns p ≥ 0.05, **p < 0.01; p = 0.0034 (EdU⁺), p = 0.9926 (OLIG2⁺/BrdU⁺). Source data are provided as a Source Data file.