FIGURE 6.

Effects of Temozolomide (TMZ) on EGFRvIII‐brain organoids. A, Scheme of treatment of brain organoids with Temozolomide (TMZ). As a negative control, DMSO was used. B‐D, After treatment with TMZ or DMSO for 10 days, the brain organoids were analysed by immunostaining using antibody recognizing cleaved caspase 3 (CCASP3). Brain organoids were generated using wt H9‐hESCs (B), monoallelic EGFRvIII (EGFR^wt/vIII)‐hESCs (C) and biallelic EGFRvIII (EGFR^vIII/vIII)‐hESCs (D). Scale bar, 50 μm. E, The percentages of CCASP3‐positive cells among total cells (DAPI⁺) were shown as graph. Results are presented as mean ± SEM. ***P < .001. N = 3 independent experiments. F‐H, After treatment with TMZ or DMSO for 10 days, the extent of proliferating cells in the brain organoids was analysed by immunostaining using antibody recognizing Ki67. Brain organoids were generated using wt H9‐hESCs (F), monoallelic EGFRvIII (EGFR^wt/vIII)‐hESCs (G) and biallelic EGFRvIII (EGFR^vIII/vIII)‐hESCs (H). Scale bar, 50 μm. I, The percentages of Ki67‐positive cells among total cells (DAPI⁺) were shown as a graph. Results are presented as mean ± SEM. **P < .01; ***P < .001; ns, not significant. N = 3 independent experiments