[Frontiers in Bioscience 14, 2212-2220, January 1, 2009]

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

Hai-Bin Kuang1, 2, 3, Cheng-Lin Miao1, 2, Wei-Xiang Guo1, 2, Sha Peng1, 2, Yu-Jing Cao1, En-Kui Duan1

1State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, P.R. China, 2Graduate School of the Chinese Academy of Sciences, Beijing 100039, P.R. China, 3Department of Physiology, School of Medicine, Nanchang University, Nanchang 330006, P.R. China

TABLE OF CONTENTS

1. Abstract
2. Introduction
3. Materials and methods
3.1. Migration assay and adhesion assay
3.2. Stable transfection
3.3. Immunofluorescence
3.4. Western blot analysis
3.5. Apoptosis analysis and cell cycle analysis
3.6. Statistical analysis
4. Results
4.1. Dkk-1 prominently enhances migration of HEK293 cells
4.2. LiCl and Genistein stimulus reverse the mobilization effect of Dkk-1
4.3. Mobilization effect of Dkk-1 is accompanied with beta-catenin dissociation from cadherin-catenin complex and E-cadherin degradation
5. Discussion
6. Acknowledgement
7. References

1. ABSTRACT

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.