Cytogenetic analysis in melanoma and nevi

We have presented data from the cytogenetic analysis of melanocytes derived from four dysplastic nevi and 14 melanomas. We have confirmed previous results from melanomas, including the loss of chromosome 6q and duplication of 1q and 7p. We did not observe an excess of rearrangements involving chromosomes 2 and 3, but we found frequent deletion of chromosomes 9p, 10p, 10q, and 11q. We observed the loss of chromosome 9 in 2 of 4 dysplastic nevi, and combining this observation with that from the melanomas suggests that deletion or inactivation of a gene on 9p may be a primary event in melanocyte transformation. Other tumor suppressor genes are likely to be involved in the transformation process, and these are most likely located on 10p, 10q, 11q, and 6q. We observed many rearrangement involving chromosome band 1p13 and suggest that activation of a gene in that band may also contribute to the transformation process.