Fig. 4

Iressa and DAPT treatment abrogates GBM-induced EC sprouting, and inhibits VEGF expression and secretion in GBM cells. CPH036 and CPH047 cells were treated with 5 µM iressa, 5 µM DAPT or a combination for 14 days. The conditioned GBM media was concentrated and subjected to EC for sprouting analysis. a, b Representative pictures showing sprouting of EC upon administration of conditioned media obtained from CPH036 or CPH047 cells treated with indicated inhibitors. c, e Relative EC sprouting quantified as total number of sprouts and total length of sprouts per sphere upon stimulation with conditioned inhibitor-treated media from either CPH036 or CPH047 cells, respectively (mean ± SEM, n = 3 measuring an average of 10 spheres per condition in each experiment). d, f VEGF mRNA levels in inhibitor-treated CPH036 and CPH047 cells were analyzed by Q-RT-PCR and normalized to the mean gene expression of the control. VEGF secretion levels (ng/ml) analyzed by ELISA from inhibitor-treated CPH036 and CPH047 cells as measured by VEGF-ELISA (mean ± SEM, n = 3). Scale bar shows 100 μm. *p < 0.05, **p < 0.01, ***p < 0.001