BCAR3 regulates actin cytoskeletal and adhesion remodeling in response to growth factor.

<p>(<b>A</b>) MDA-MB-231 cells were transfected with siCtl, siB3-1, or siB3-2 oligonucleotides and incubated for 24 hours prior to plating onto 10 µg/ml fibronectin-coated glass coverslips. Cells were serum-starved for 16–18 hours, stimulated with 100 ng/ml EGF for 0 or 30 minutes, and then fixed and processed for immunofluorescence as described in the methods. Actin and vinculin-containing adhesions were visualized with phalloidin (red) and vinculin (green) antibodies, respectively. Merged images are shown in the right panels; insets show higher magnifications of actin and adhesion structures. Scale bars = 15 µm. (<b>B</b>) The percentage of siCtl (black bars), siB3-1 (gray bars), and siB3-2 (white bars) treated cells containing actin-rich stress fibers was determined. Data represent the mean ± SEM of at least 730 cells per condition from 3 separate experiments (*, p<0.04). (<b>C</b>) MDA-MB-231 cells were transfected as described in (A). Representative immunoblots are shown confirming knockdown of BCAR3 using 2 separate siRNA oligonucleotides.