Fig. 3

Induction of autophagy and apoptosis, and decrease of glioma stemness marker proteins by synergistic combination treatments in glioma tumor-initiating cells. a Cells were treated with vehicle as control (C), erlotinib (E), sorafenib (S), U0126 (U) and combinations for indicated duration, and 10 μg of extracted proteins in each sample were subjected to immunoblotting using indicated antibodies to detect total or phosphorylated (p-) proteins. Concentrations of drugs were as follows: erlotinib; 0.6 μM for GSC11 and 6 μM for GSC20, sorafenib; 4 μM for GSC11, U0126; 10 μM for GSC11 and 20 μM for GSC20. β-actin was examined as loading control. Results shown are representative of at least two independent experiments. b and c GSC11 cells with transfection of GFP-LC3 were treated with vehicle (control), 0.6 μM erlotinib, 4 μM sorafenib or the combination for 48 h. b Scale bar is 5 μm. c Cells with punctate pattern of GFP-LC3 were counted as autophagic cells. Data shown are the means of two independent experiments. *means significant difference (p < 0.05) between any two of the four groups by ANOVA and Tukey’s post hoc analysis