Figure EV1. Temozolomide represses SOX10 expression.

(A) Western blot analysis showing short-term (7-day) temozolomide treatment effects on SOX10 and SOX9 expression in NCH421k and NCH441 human glioblastoma cells. (B) Temozolomide-induced reduction of SOX10 expression (left) and cell proliferation (right) of GFP and luciferase dual-labeled NCH644 glioblastoma cells growing in iPSC-derived cerebral organoids. Treatment with DMSO or 100 µM TMZ was started on day 6, and organoids were harvested on day 18. SOX10 expression was analyzed by recording mean fluorescence intensities by flow cytometry on day 18. Cell proliferation was monitored by bioluminescence (photon flux per second) imaging every 3 days. n = 3 organoids; mean ± SEM; P values were computed with two-tailed unpaired T tests. (C) Western blot analysis showing MGMT expression levels in SOX10-high glioblastoma stem cells. Protein lysate from Jurkat cells was used as the positive control for MGMT expression. (D) Immunofluorescence staining of Sox10 and Sox9 in the vehicle and TMZ-treated mice (Pdgfb/Akt RCAS glioblastoma mouse model) (Rusu et al, 2019). Scale bars = 100 µm. Related to Fig. 1.