nmb , a novel gene, is expressed in low‐metastatic human melanoma cell lines and xenografts

From a subtractive cDNA library, we isolated several cDNA clones which showed differential expression between highly and lowly metastatic human melanoma cell lines. One clone, designated nmb , showed preferential expression in the low‐meta‐static cell lines and was chosen for further characterization. Sequence analysis revealed that this clone represents a novel gene, encoding a putative transmembrane glycoprotein which showed the highest homology to the precursor of pMEL17, a melanocyte‐specific protein. nmb RNA expression was absent in most tumor‐cell lines tested and not restricted to the melanocytic lineage. Transfection of a partial nmb cDNA into a highly metastatic melanoma cell line (BLM) resulted, in 2 of 3 transfectants, in slower subcutaneous tumor growth and, in 1 of 3 transfectants, in reduction of the potential for spontaneous metastasis in nude mice. © 1995 Wiley‐Liss, Inc.