Dickkopf-1 enhances migration of HEK293 cell by beta-catenin/E-cadherin degradation.

Migration is an important process during cellular activity and embryo development. We recently showed that Dickkopf-1(Dkk-1), an antagonist of Wnt/ beta-catenin signaling pathway, could promote trophoblast cell invasion during murine placentation. However, mechanism of Dkk-1 action on cell migration was not clear. The objective of this study was to further evaluate the effect of Dkk-1 on cell migration and to identify the underlining mechanisms. Functional assays with stable Dkk-1 transfected HEK293 cells revealed that Dkk-1 expression increased cell migration by decreasing cell-cell adhesion, not cell-matrix adhesion. Treatment with LiCl and Genistein (widely used inhibitor of glycogen synthase kinase-3 and tyrosine protein kinase, respectively.) could inhibit the migration effect of Dkk-1, and significantly increased the membrane localization of beta-catenin and E-cadherin in HEK293 cells transfected with Dkk-1. Further data showed that HEK293 cells transfected with Dkk-1 have significantly decreased accumulation of both beta-catenin and E-cadherin at the cell membrane. Together, our data suggest that Dkk-1 stimulates the release of beta-catenin from cell membrane and facilitates cell migration which accompanies degradation of beta-catenin/E-cadherin.