TGF-β1 induces EMT in GBM cells. (a) MTT assay of cell viability in LN18 and U87 cells following TGF-β1 treatment for 48 hours. (b) Western blotting showed that TGF-β1 induced downregulation of E-cadherin, upregulation of N-cadherin, β-catenin, Vimentin, and Twist1 expression in a dose-dependent manner. (c) Representative morphological images were photographed under Olympus microscope for LN18 (× 100 magnification) and U87 cells (× 100 magnification) treated with or without TGF-β1 (10 ng/ml) for 48 hours. (d) TGF-β1-induced EMT enhanced the migratory ability of LN18 and U87 GBM cells. Representative wound-healing images were photographed under Olympus microscope for LN18 (× 100 magnification) and U87 (× 40 magnification) GBM cells. The mean level of migration distance observed in three random fields for each condition was showed in histograms. Each independent experiment was repeated three times.