HRG-β1 induces upregulation of the transcription factor Snail and EMT markers in MCF7 cells. (a) The cells were incubated with 25 ng/ml of HRG-β1 for different times after serum starvation. The expressions of Snail, E-cadherin, vimentin, and fibronectin were examined by western blotting. β-actin was evaluated as a loading control. Data represent the means ± SD of three independent experiments. *P < 0.05, significant difference. (b) Immunofluorescence staining of vimentin protein. Cells were treated with or without 25 ng/ml of HRG-β1 for 24 h. The green color represents staining of vimentin and the blue color represents nuclear DNA staining by DAPI (magnification, ×200).