Cell adhesion and communication proteins are differentially expressed in melanoma progression model

Cutaneous melanoma is an aggressive cancer derived from skin melanocytes. Tissue microarrays are being used to evaluate the roles of numerous proteins implicated in some of the pathways involved in melanoma pathogenesis. Based on a previous study using a complementary DNA microarray platform, the aim of this study was to evaluate the immunohistochemical expression of the adhesion and communication molecules connexin 43, desmocollin 3, cytokeratin 5, kallikrein 6, and kallikrein 7 in a melanoma progression model. We analyzed 59 common nevi, 22 atypical nevi, and 162 invasive and 29 metastatic melanomas on tissue microarrays using digital microscopy. The expression of desmocollin 3 and connexin 43 was higher in melanomas (P < .001). Kallikrein 6 expression was higher in melanomas than in common nevi (P < .006). The expression of cytokeratin 5 and kallikrein 7 was higher in atypical nevi than in melanomas (P < .001) and was higher in melanomas than in common nevi (P < .001). The expression of desmocollin 3 and connexin 43 in melanomas indicates loss of cell-cell interactions, which starts in the early steps of the melanoma progression model. Keratin expression in melanomas may play a particular role during melanocyte development. The expression of kallikrein 7 and kallikrein 6 in melanomas may be responsible for the loss of cell-cell adhesion.