Inhibition of cell migration by cortactin knockdown. (A) Cortactin and FAK knockdown by RNA interference. Ctrl, HT1080 cells; Luci, luciferase siRNA control; Cttn, cortactin siRNA fragment; FAK, FAK siRNA fragment. Cortactin, FAK and α-tubulin were detected by western blotting. (B) Inhibition of cell migration by FAK knockdown. Bar, 50 μm. The track depicts the positions of the cells taken at 3-min intervals. The picture shows the cell at the starting point (0), at 180 min (180) and at 360 min (360 min). The plot is the results of 83 control RNAi cells (Luci) and 81 FAK RNAi cells (Cttn). ***P < 0.001. (C) Inhibition of cell migration by PP2. Bar, 200 μm. Ctrl, normal medium; PP2, medium with 10 μM PP2. Cell migration was determined by measuring the width of the gap at 4-minute intervals and normalized by the initial width of the gap. The averaged results of six wound-healing gaps at 8-minute intervals are plotted. (D) Inhibition of cell migration by overexpressing the FAK mutant (Y397F). Bar, 50 μm. GFP-tagged FAK or mutated FAK (Y397F) was expressed in HT1080 cells. The migration of the EGFP-positive cells was tracked. The inserts are EGFP fluorescence pictures of cells taken at 360 min. 72 GFP-FAK cells and 57 GFP-FAK (Y397F) cells were plotted. ***P < 0.001. (E) Inhibition of cell migration by cortactin knockdown. The labels are the same as in panel B.