Fig. 1

TGF-β1 was used to establish EMT cell models. a Morphology of A549 cells changed from E- to M- phenotype after TGF-β1 treatment. The mRNA (b) and protein (c) levels of EMT-related markers of A549 cells changed after being induced by TGF-β1. TGF-β1 significantly reduced E-phenotype marker (E-cadherin (E-cad)) levels, but increased the M-phenotype marker (N-cadherin (N-cad), vimentin (Vim), fibronectin (Fib) and snail) levels in a TGF-β-concentration-dependent manner but not a strict time-dependent manner. d The wound healing assays proved that TGF-β1 treatment can significantly increase cell migration abilities. The wound widths were significantly shorter at 24 h after TGF-β1 treatment than in the no-treatment group (P < 0.05), and this difference was more significant after 48 h treatment (P < 0.01). e Invasion assays were used to determine cell invasion. Invaded cell numbers were significantly higher in TGF-β1 treatment than no-treatment groups, indicating TGF-β1 can improve cell invasion ability