Fig. 2: Differentiation in white matter is a general GBM response.

a representative immunofluorescence image of a SOX10⁺ patient-derived xenograft (PDX 23) stained for SOX10 (red), oligodendrocyte-specific protein (OSP, grey) and human-specific nuclear antigen (HuNu, green) to label all tumour cells. Scale = 500 µm. b quantification of percentage of SOX10⁺/HuNu⁺ tumour cells in white and grey matter of indicated patient-derived xenografts. n = 4 independent xenograft models. For each xenograft, ≥550 cells were quantified across 2 independent ROIs selected within white or grey matter. p = 0.05, Mean, paired one-tailed Student’s t test. c quantification of percentage of proliferating SOX10⁺ and SOX10⁻ tumour cells in the corpus callosum of indicated xenografts. For each xenograft, ≥500 SOX10⁺ or SOX10⁻ cells were quantified across 2 independent ROIs, n = 4 independent xenograft models. p = 0.05, Mean, paired one-tailed Student’s t-test. d MBP (grey) and SOX10 (red) immunofluorescence staining of white matter regions of patient tumours. SOX2 (green) was used to identify tumour cells and distinguish them from resident glia. Cases shown are the original tumours from which lines GL23, GL67 and GCGR L12 used in this study have been isolated. Inset shows a close-up of the same image. Scale = 50 µm. e quantification of percentage of SOX2⁺/SOX10⁺ and SOX2⁺/SOX10⁻ tumour cells undergoing proliferation (Ki67⁺) in patient tumours. For each case, ≥300 cells were quantified across 2 independent ROIs, n = 7 cases. P = 0.002, Mean, paired one-tailed Student’s t-test. f pie chart representation of SOX10 expression in 23 patient tumours. – denotes absence, and + to +++ increasing frequency of SOX10⁺ cells within the tumour.