Fig. 3: GSCs-derived β8 integrin expression inhibits angiogenic capacity of human brain microvascular endothelium.

A hBMECs were co-cultured with β8⁻ or β8⁺ GSCs for 24 h, cell proliferation was determined via CCK-8 assay. B hBMECs co-cultured with β8⁻ or β8⁺ GSCs were subjected to Edu staining. Scale bar = 100 μm. C Migration assay was conducted of hBMECs that co-cultured with β8⁻ or β8⁺ GSCs. D Tube formation assay on Matrigel was performed of hBMECs that co-cultured with β8⁻ or β8⁺ GSCs. Scale bar = 50 μm. E hBMECs were co-cultured with β8⁻ or β8⁺ GSCs. Spheroid-based angiogenesis assay was performed. F The protein levels of phosphorylated Smads, c-Myc and p21 in hBMECs cultured with β8⁻ or β8⁺ GSC#1 (left panel). Indicated proteins in hBMECs treated with scrambled siRNA or siTGFβR2, followed by co-culture with GSC#2. G Orthotopic xenografts GBM model was established with β8⁻ or β8⁺ GSC#2. Sections of five random mice of each group were selected and immunofluorescence stained for CD34. Scale bar = 100 μm. Uncropped western blot images are shown in Supplementary Fig. 5. Results are represented as mean ± SD of biologically triplicate assays. *p < 0.05, **p < 0.01, ***p < 0.001.