Fig. 4: Olig2 SUMOylation inhibits apoptosis in orthotopic xenografts.

Intracranial glioblastoma models of Olig2-expressing tumors were created in mice as described in Fig. 3d. Transplanted nude mice were treated with saline (−TMZ) or TMZ (+TMZ) and sacrificed 5–7 days later. a Representative images of H&E staining of the tumors. Frozen sections were prepared and subjected to H&E staining. Scale bar = 50 μm. b, d Olig2 SUMOylation promotes tumor proliferation after TMZ administration. Proliferating cells were labeled by Ki67 staining. The bar graph in d shows the percentage of Ki67⁺ (red) among GFP⁺ (green) cells. Scale bar = 50 μm. c, e Olig2 SUMOylation inhibits tumor apoptosis after TMZ administration. Cells undergoing apoptosis were labeled by TUNEL staining. The bar graph in e shows the percentage of TUNEL⁺ (red) among GFP⁺ (green) cells. Images shown are representatives of at least three independent experiments. Bar graphs are presented as means ± s.e.m. of at least three independent experiments. Statistical significance was assessed by one-way ANOVA with Tukey’s multiple comparison test. *p < 0.05.