Plasticity of cadherin-catenin expression in the melanocyte lineage

Cadherins are calcium-dependent cell adhesion receptors with strong morphor egulatory functions, To mediate functional adhesion, cadherins must interac t with actin cyto-skeleton. Catenins are cytoplasmic proteins that mediate the interactions between cadherins and the cytoskeleton. In addition to the ir role in cell-cell adhesion, catenins also participate in signaling pathw ays that regulate cell growth and differentiation. Cadherins and catenins a ppear to be involved in melanocyte development and transformation. Here, we investigated the function of cadherin-catenin complexes in the normal deve lopment and transformation of melanocytes by studying the patterns of expre ssion of the cell-cell adhesion molecules, E-, N- and P-cadherin, and the e xpression of their cytoplasmic partners, alpha-, beta- and gamma-catenin du ring murine development. Similar analyses were performed in vitro using mur ine melanoblast, melanocyte, and melanoma cell lines in the presence and ab sence of keratinocytes, the cells with which melanocytes interact in vivo. Overall, the results suggest that the expression of cadherins and catenins is very plastic and depends on their environment as well as the transformat ion status of the cells. This plasticity is important in fundamental cellul ar mechanisms associated with normal and pathological ontogenesis, as well as with tumorigenesis.