Validation of the transactivation of c-Met, Axl and PDGFR-α in human bladder cancer cells. A: Levels of c-Met, p-c-Met, Axl and PDGFR-α were measured in bladder cancer cell lines UB40 and UB47 by Western blotting after serum starvation for 24 h followed by HGF treatment for 10 min. B. c-Met, Axl and PDGFR-α protein expression was measured in UB40 cells after transfection with RTK-specific siRNAs (500 nM) by Western blotting. β-actin is a loading control. M: Mock transfection control. S: scramble siRNA (500 nM) is a negative control. The numbers under each band represent the relative intensity.