Figure 2: Effect of SKIP knockdown on TGF-β1-induced uPA expression. (a) Secreted uPA activity determined by zymography in the serum-free conditioned media of PC-3 cells transfected either with control siRNA (siR-C) or siRNA-SKIP (siR-SKIP), and treated or not with TGF-β1 for 24 h. (b) Transactivation of uPA promoter in PC-3 cells transiently transfected with uPA promoter construction and siR-C, siR-SKIP or SKIP-Ha tagged expressing vector (SKIP-V) and treated with TGF-β1 for 48 h. The correct expression of ectopic SKIP-HA in PC-3 cells was tested by Western Blot (insert).