The TβRI kinase activity is required for EMT in epithelial cells with down-regulated ShcA expression.

<p>(A–D) The TβRI kinase inhibitor SB431542 inhibits Snail mRNA expression, assessed by qRT-PCR and normalized to RPL19 mRNA (A), EMT morphology, assessed by phase contrast microscopy (B), downregulation of cortical E-cadherin, redistribution of actin, and activation of fibronectin expression, assessed by immunofluorescence (C), and cell invasion through Matrigel, assessed as in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1002325#pbio.1002325.g002" target="_blank">Fig 2B</a> (D), in control NMuMG cells treated or not with TGF-β for 48 h, and NMuMG cells transfected with ShcA siRNA (siShc-a). (E–G) SB431542 inhibits Slug mRNA expression, assessed by qRT-PCR and normalized to RPL19 mRNA (E), EMT morphology, assessed by phase contrast microscopy (F), and the down-regulation of cortical E-cadherin, redistribution of actin and activation of fibronectin expression, assessed by immunofluorescence (G), in control HaCaT cells treated or not with TGF-β for 72 h, or HaCaT cells transfected with ShcA siRNA (siShc-c). DAPI staining visualized the nuclei. The graphs (A, D, E) show averaged values of three independent experiments, with error bars indicating standard errors, based on three experiments. Statistical analyses were performed using two-tailed two-sample unequal variance <i>t</i> test. *, <i>p</i> < 0.05; **, <i>p</i> < 0.002. Supplemental data are shown in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1002325#pbio.1002325.s005" target="_blank">S4 Fig</a> and <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1002325#pbio.1002325.s001" target="_blank">S1 Data</a>.