Figure 4.

β-Catenin depletion eliminates E-cadherin–mediated growth inhibition and increases cell proliferation. (A) Western blot of β-catenin and E-cadherin in lysates from cells transfected with or without siRNA against GFP or β-catenin (three different targets inside β-catenin coding sequence: β-cat#1, β-cat#2, and β-cat#3; see Materials and Methods). (B) Indirect immunofluorescence staining of β-catenin and E-cadherin in MCF-7 and SW480/E-cadherin FL cells transfected with siRNAs against GFP or β-catenin. (C and D) Binding of Fc-hE–coated microspheres promote a specific decrease in the proliferation of cells transfected with siRNA targeting GFP protein in MCF-7 (C) and SW480/E-cadherin FL (D) cells, respectively. These effects were lost when cells were transfected with siRNA targeting β-catenin. (E and F) MCF-7 and SW480/E-cadherin FL cells transfected with siRNA targeting GFP (circles) or β-catenin (squares) were plated at 10⁵ cells/well, and then they were harvested at the indicated times, and the number of viable cells was counted. Data are expressed as mean ± SEM (*p < 0.05).