Inhibitory effect of paclitaxel on endothelial cell adhesion and migration

The long-term success of percutaneous coronary interventions has been limited by restenosis. Therefore, local delivery of paclitaxel, an antiproliferative agent, using drug-eluting stents has been applied to prevent in-stent restenosis. However, paclitaxel not only inhibits smooth muscle cell proliferation, but also delays re-endothelialization of the damaged site, which may cause potentially life-threatening cardiovascular adverse events, especially late and very late stent thrombosis. We investigated the role of paclitaxel in endothelial cell line ECV304 adhesion and migration. Accordingly, changes in vasodilator-stimulated phosphoprotein protein (VASP) phosphorylation and cAMP-dependent protein kinase activity during ECV304 cell detachment and reattachment were investigated as well. The results showed that the decrease in VASP phosphorylation paralleled the inhibition of cAMP-dependent protein kinase (PKA) activity in the presence of paclitaxel (10 microg/l). Cell adhesion assay and two- and three-dimensional cell migration assays were performed to determine the effect of paclitaxel on the adhesion and migration of ECV304 cells. Paclitaxel significantly suppresses the adhesion (p < 0.05) and migration of ECV304 cells (p < 0.05). These data suggest that the inhibitory effect of paclitaxel may be produced by decreasing the phosphorylation of VASP via inhibition of PKA activity during ECV304 cell adhesion and migration.