Figure 2. Down-regulation of E-cadherin induces cell adhesion and invasion via up-regulation of α₅-integrin.

A, Western blot. Cell lysates were resolved by SDS-PAGE and immunoblotted with an antibody against α₅-integrin or E-cadherin. Blots are representative of three experiments. B, adhesion to ECM. E-cadherin- or control siRNA–transfected RMUG-S cells were fluorescently labeled and plated onto 96-well plates coated with the indicated ECM components. Plates were washed and the number of adherent cells was quantified by measuring fluorescence intensity. Columns, mean of three independent experiments. Representative images of labeled cells that have attached are in the right panel. C, invasion. RMUG-S cells were transfected with the E-cadherin siRNA or control siRNA or not transfected (mock). The transfected cells were placed in a Matrigel-coated Boyden chamber and allowed to invade for 24 h. α₅-Integrin–blocking antibody (IIA1) or nonspecific mouse IgG was added as indicated. Representative photographs are shown. The results were from three independent experiments. Significant differences are indicated by * for P < 0.05, ** for P < 0.01, *** for P < 0.001, and n.s. for not significant.