Figure 7.
Blockade of the MAPK pathway antagonizes c18-induced motility. (A) Stimulation of MAPK phosphorylation by c18 NC1 and ES dimer. HUVECs on Matrigel in the presence or absence of ES monomer (3,000 nM), ES dimer (50 nM), or c18 NC1 (50 nM), and harvested and analyzed by Western blotting using anti–phospho-MAPK antisera after 24 h. (B) Time kinetics of MAPK activation by ES dimer. HUVECs on Matrigel for 16 h were stimulated with ES dimer (50 nM) or ES monomer (3,000 nM) for the indicated times, followed by harvest and Western blotting with anti–phospho-MAPK antisera. Stimulation was measured by densitometry and represents the average of three independent experiments. Similar results were observed for NC1. (C and D) Inhibition of ES dimer–induced motility by the MEK inhibitor PD98056 but not the p38 inhibitor SB203580. HUVECs were seeded on Matrigel for 16 h followed by 60-min preincubation with or without PD98056 or SB203580 (50 μM), followed by treatment with hES dimer (50 nM) for 12 h, and then harvest for anti–phospho-MAPK Western blot (C) or phase–contrast microscopy (D) (magnification ×40).