This study investigated the expression of intercellular adhesion molecule-1 (ICAM-1), interleukin-2 receptor (IL-2R), integrins and E-cadherin (E-CD) in vivo and in vitro melanoma cells and their adhesion to extracellular matrix (ECM) as well as endothelial cells (HUVEC) in order to characterize the biological processes of melanoma invasion and metastasis. IL-2R was expressed in 21% of primary cutaneous melanoma, whereas 43% were positive in metastatic melanomas, suggesting that IL-2 may increase the growth of melanoma cells in certain subtypes. Integrin α2β1 was expressed highly in SK-MEL-118, and α2β1 was increased in a time- and dose-dependent manner by TPA treatment. Furthermore, the phorbol ester, TPA-induced α2β1 was mediated by calmodulin kinase, but not by protein kinase C (PKC). However, the adherence of SK-MEL-118 to HUVEC treated with TPA was decreased by 40%, suggesting that TPA affects a signaling mechanism. E-CD expression in primary melanoma did not show any correlation with the tumor invasion indexes. It was, however, indicated that primary melanoma cells adhere to each other through E-CD and that its expression correlates with invasion
