SENP1 interference enhances transforming growth factor (TGF-β)/SMADs signals, and inhibits epithelial mesenchymal transition (EMT) in PC3M cells. (A) PLKO.1-shSENP1 increases SMAD4 protein expression. PC3M cells were infected with 20 MOI PLKO.1-shSENP1 or PLKO.1-shScramble. 48 h later, cells were collected and SMAD4 protein was detected by Western-blotting; (B) SENP1 silencing decreased SMAD4 mRNA expression. At 24 and 48 h post-infection, cells were collected, and SMAD4 mRNA expression was detected by real-time RT-PCR; (C,D) SENP1 interference up-regulates E-cadherin protein, and reduces vimentin protein in PC3M cells. At 48h after infection with lentiviral vectors, protein expression of E-cadherin (C) and vimentin (D) was analyzed by Western-blotting as described above. All the data were obtained from at least three independent experiments, and are shown as mean ± s.e.m. ** p < 0.01, *** p < 0.001, vs. PLKO.1-shScramble group.