FIGURE 8.

293 cr-u-PAR-expressing cells promote u-PA-independent migration. Non-transfected 293 (gray bars)-, 293 wt u-PAR (white bars)-, and 293 cr-u-PAR (black bars)-expressing cells were serum-starved and suspended in serum-free DMEM. Cells were either pre-treated with serum-free DMEM and allowed to migrate over Vtn-coated chambers with no serum gradient (no serum), pre-treated with serum-free DMEM and allowed to migrate toward 10% fetal calf serum (serum), or pre-treated with 0.5 nm tcu-PA and allowed to migrate toward 10% fetal calf serum (0.5 nm tcu-PA) for 2 h at 37 °C. Samples were analyzed as described under “Experimental Procedures.” Data represent the means ± S.D. of at least three individual replicates and were analyzed using a Student's t test (*, p < 0.0001 and **, not significant).