Figure 5. α₅β₁-Integrin signals through c-Met to activate FAK and Src.

(a) HeyA8 cells were transfected with c-Met siRNA or with scrambled siRNA, plated on fibronectin and treated with human α₅Ab. Cells were lysed, resolved on SDS-PAGE, transferred to nitrocellulose membrane and probed with the indicated antibodies. (b) HeyA8 cells were plated on fibronectin and treated with human α₅Ab as indicated for 24 h. The cells were then treated with HGF/SF for 30 min and immunoblotting performed with the specified antibodies. Results in (a) and (b) are representative of three independent experiments. (c) SKOV3ip1 xenografts were treated with human α₅Ab or with IgG as described in Figure 1 (b) Left: Tumor lysates were immunoblotted with the indicated antibodies. Right: Representative image of tumor sections stained for p-FAK-Y397 (x200). Images of sections from 5 mice were quantified using Image J (*p<0.001). (d) Immunoprecipitation. HeyA8 cells were plated on fibronectin and treated with human α₅Ab or control IgG for 24 h followed by immunoprecipitation with an antibody against c-Met or Src, respectively followed by immunoblotting (WB) Src and c-Met. All results are representative of at least three independent experiments.