Focal adhesion kinase: important to prostaglandin E2-mediated adhesion, migration and invasion in hepatocellular carcinoma cells.

Prostaglandin E2 has been implicated in cell growth and metastasis in many types of cancers. However, the effects of PGE2 and its mechanism on cell adhesion, migration, and invasion have not been clarified yet. In this study, we found PGE2 treatment significantly increased the cell adhesion, migration, and invasion in hepatocellular carcinoma (HCC) cells. In addition, the effects of PGE2 were found to be associated with focal adhesion kinase (FAK). PGE2 treatment increased the phosphorylation and synthesis of FAK in a dose-dependent manner. RNA interference targeting FAK suppressed PGE2-mediated cell adhesion and migration. Furthermore, the downstream proteins of FAK, paxillin and Erk2, were also activated by PGE2. PGE2 treatment increased the phosphorylation and synthesis of paxillin in a dose-dependent manner. PGE2 treatment also induced the phosphorylation of Erk2. PD98059, the specific inhibitor of MEK, suppressed PGE2-mediated cell adhesion and migration. However, it had no effect on PGE2-induced activation and synthesis of FAK. These results demonstrated that PGE2 greatly induced HCC cell adhesion, migration, and invasion by activating FAK/paxillin/Erk pathway.