Cdc42 depletion inhibits cancer cell intercalation between ECs. (A) CFSE-labeled PC3 cells transfected with control siRNA were filmed for 300 min on HUVECs. Asterisks mark PC3 cells that intercalate; arrowheads indicate a cell that does not intercalate. Bar, 50 µm. (B and C) Graphs show time of intercalation for individual cells. Cells were filmed on HUVECs for 300 min. In each experiment, ≥100 cells were analyzed in at least three fields. Data are expressed as the percentage of total cells. (B) PC3 cells transfected with the indicated siRNAs. (C) PC3 cells transfected with the indicated siRNAs were transfected after 48 h with siRNA-resistant-cDNAs encoding GFP-tagged Cdc42, Rac1, and RhoA, respectively. (D) Distance migrated on top of ECs before intercalation. Data are expressed as the percentage of control cells. Values (B–D) are means ± SEM (error bars; n ≥ 3); ***, P < 0.001; **, P < 0.01; *, P < 0.05.