Figure 1.

Slug mediates the epithelial mesenchymal transition (EMT) in A549 cells. Stable transfectants expressing enhanced green fluorescent protein (EGFP) only or EGFP and Slug were designated as A549/EGFP and A549/Slug, respectively. (A) Morphological changes of A549/EGFP and A549/Slug cells. (B) The mRNA expression levels of Slug, E-cadherin, fibronectin 1, and vimentin were determined using real-time RT-PCR in both cell lines. GAPD was used to normalize the expression levels. E-cad: E-cadherin, FN1: Fibronectin 1, VIM: Vimentin, Rel mRNA: normalized mRNA expression levels (target genes/GAPD × 10³). The data shown represents the average ± SD of three independent experiments. (C) Western blot analysis for Slug, E-cadherin, N-cadherin, vimentin, and fibronectin. β-actin was used as an internal control. (D) Immunofluorescence staining of E-cadherin (red) and vimentin (red). Cells were treated with DAPI (blue, 6-diamidino-2-phenylindole) to stain the nucleus. PCR, polymerase chain reaction; SD, standard deviation; mRNA, messenger ribonucleic acid.