Fig. 4.

Ten14 activates migration at levels that fail to stimulate proliferation. Quiesced NR6WT cells were exposed to various concentrations of ligand. Proliferation (filled squares) and motility (open circles) were assessed as described and values plotted. Alternatively, cells were either incubated with PD 98059 or transected with siRNA against PLCγ1 before assessing migration and proliferation. A: For cells treated with EGF, we observed a linear dose response for both migration (open circles) and proliferation (filled squares) over different concentrations. Shown are mean ±s.e.m., normalized to treatment with diluent alone, of experiments performed at least 5 times (in triplicate). ^*for proliferation and ^**for migration denotes P < 0.05 compared to diluent alone. B: In the case of Ten14, we observed migration at levels of ligand that fail to promote proliferation, suggesting a separation in the migration/proliferation profile. However, at very high doses, the proliferative effects of Ten14 are enhanced. Shown are mean ±s.e.m., normalized to treatment with diluent alone, of experiments performed at least 5 times (in triplicate). ^*for proliferation and ^**for migration denotes P < 0.05 compared to diluent alone. C,D: Cells incubated with ERK/MAPK inhibitor PD98059 show a decrease in proliferation but no significant effects on proliferation for cells treated with EGF or Ten14 (P < 0.05). E,F: However, cells treated with siRNA against PLCγ1 demonstrated a significant decrease in migration without significant effects on proliferation, suggesting that the enhanced migration observed at subsaturating doses of ligand (see B) may be mediated mainly through activation of PLCγ1 (P < 0.05).