Cdc42, Rac1, and RhoA depletion inhibits EC junctional opening. (A) CFSE-labeled PC3 cells were added to HUVECs for 30 and 60 min, then stained for β-catenin and F-actin. Cell outlines are shown. A gap in the endothelial monolayer by the control PC3 cell is outlined and marked with an asterisk. Arrows show the disappearance of β-catenin. Bar, 50 µm. (B and C) Quantification of sites of cancer cell adhesion with respect to EC junctions and the status of EC junctions near cancer cell adhesion sites. Data are expressed as the percentage of total cells analyzed; ≥50 cells/experiment. Values are means ± SEM (error bars; n ≥ 3); ***, P < 0.001; **, P < 0.01; *, P < 0.05.