Fig. 1. p90RSK mediated TGF-β1-induced epithelial-to-mesenchymal transition. A: A549 lung epithelial cells were treated with increasing concentrations of FMK for 1 hour and incubated with TGF-β1 (2 ng/ml) for 48 hours. Levels of E-cadherin, N-cadherin, p-p90RSK, and p90RSK were analyzed by immunoblotting. Bar graphs present the densitometric results of Western blot bands. ANOVA: *, p<0.05 versus CON. ^†, p<0.05, ^††, p<0.01 versus TGF-β1 treated. B: A549 cells were transduced with Ad-DN-RSK or Ad-LacZ for 1 day and then treated with TGF-β1 (2 ng/ml) for 48 hours. Protein levels were analyzed by immunoblotting using specific antibodies against E-cadherin, N-cadherin, p-p90RSK, p90RSK, and tubulin. Bar graphs present the densitometric results of Western blot bands. ANOVA: *, p<0.05; **, p<0.01 versus CON. ^†, p<0.05, ^††, p<0.01 versus TGF-β1 treated. C: A549 cells were pretreated with 10 µM FMK for 1 hour and then incubated with TGF-β1 (2 ng/ml) for 48 hours. The mRNA levels of E-cadherin and N-cadherin were determined by RT-qPCR. D: A549 cells were transduced with Ad-DN-RSK or Ad-LacZ for 1 day and treated with TGF-β1 (2 ng/ml) for 48 hours. The mRNA levels of E-cadherin and N-cadherin were determined by RT-qPCR. Relative expression levels were normalized versus GAPDH. Results are presented as the means±SDs of three independent experiments that produced similar results (*, p<0.05 versus CON. ^†, p<0.05, ^††, p<0.01 versus TGF-β1 treated.).