Dickkopf-1 inhibits the invasive activity of melanoma cells

BACKGROUND: Malignant melanoma (MM) has the highest morbidity of any malignant tumour. It is known that the Wnt pathway of enhances the development of melanoma. Dickkopf (DKK)-1, an inhibitor of the canonical Wnt/β-catenin pathway, might also inhibit the development of MM. AIM: To examine the influence of DKK-1 expression on the invasive activity of MM cells. METHODS: To detect DKK-1 expression level we performed immunohistochemistry on human tissue sections of normal skin, malignant melanoma (MM) in situ, and MM with lymph-node metastasis. To clarify the role that DDK-1 plays in the invasive activity of MM cells, we performed a scratch-wound healing assay and Transwell invasion assay for A375 cells infected with appropriate recombinant adenoviruses, then assessed the migration of these cells. RESULTS: Fewer DDK1-overexpressing A375 cells than control cells migrated to the scratch-wound area or through the pores of the Transwell membrane to the lower wells. Downregulation of DKK-1 in A375 cells had the opposite effect. CONCLUSIONS: In the present study, we found for the first time that DKK-1 expression inhibits the invasive activity of MM cells.