IDENTIFICATION OF NOVEL CADHERINS EXPRESSED IN HUMAN-MELANOMA CELLS

Cadherin molecules are essential for tissue morphogenesis and are also related to cancer invasion and metastasis. Although normal melanocyte s express E- and P-cadherin, the activity and expression of E- and P-c adherin in melanoma cells are still unknown, We measured the homophili c adhesion activity of human normal epidermal melanocytes and the mela noma cell lines MeWo and A375, The melanoma cells showed stronger homo philic adhesion activity than did the melanocytes, despite the lower e xpression of E- and P-cadherin in the melanoma cells, This result sugg ested that melanoma cells expressed other types of homophilic adhesion molecules, Using degenerate primers to amplify multiple cadherin subt ypes, we performed a polymerase chain reaction (PCR) with the first st rand of cDNAs generated by reverse transcription of the mRNAs of the m elanoma cells, and we isolated two known cadherin fragments, N-cadheri n and PC42, and six novel cadherin fragments, cadherins ME1-ME6, The r everse transcriptase-PCR using specific primers of cadherins including E-, P-, and N-cadherins, PC42, and cadherins ME1-ME6 revealed that th e melanoma cells expressed more kinds of cadherin molecules than did t he melanocytes. Such cadherins may play an important role in melanoma cell-cell adhesion.