Gene expression profiling of melanocytic lesions.

DNA microarrays, microscopic grids of DNA, can be used to assess gene expression within a particular cell or cell population. Since DNA from thousands of genes can be hybridized and analyzed in one experiment, researchers can globally characterize genes expressed in normal and various pathologic states. To accurately assess the differences between normal and pathologic states, one derives cDNA from control and diseased tissue specimens for genes expression profiling. For these reasons, microarray technology may be of particular interest to dermatopathologists and dermatologists interested in understanding cutaneous disease because these physicians have access to tissue specimens. In addition, microarray technology is an efficient way of identifying molecules expressed in a cell population; therefore, it can be used to search for unique immunohistologic markers. To this end, we have used microarray technology to define differences in the gene expression profile of nevi and melanomas. In this manuscript, we discuss the results of our study, which confirm previously known differences in gene expression between melanoma and nevi. While a few genes appear slightly overexpressed in nevi, a number of genes involved in regulating cell proliferation were upregulated in melanoma, such as cyclin D1, cdc2-related protein kinase, c-Myc binding protein, early growth response protein 1, and pleiotrophin. "Housekeeping" genes such as glyceraldehyde 3-phosphate dehydrogenase were expressed at similar levels in melanoma and nevi. Surprisingly, a majority of genes were expressed at similar levels in both nevi and melanoma. Based on this study, DNA microarray technology appears to be a valuable tool for identifying genes that may be specifically expressed in cutaneous lesions.