Identification by cDNA Microarray Technology of Genes Modulated by Artificial Ultraviolet Radiation in Normal Human Melanocytes: Relation to Melanocarcinogenesis

Target genes of ultraviolet stress response in cutaneous melanocytes, potentially associated with solar-induced melanocarcinogenesis, were characterized by cDNA microarray technology. In cultured normal human melanocytes, 198 genes out of ≈9000 arrayed were found modulated ≥ 1.9 times following artificial ultraviolet - mainly ultraviolet-B - irradiation (100 mJ per cm2). Among them, 159 corresponded to known sequences, the encoded proteins being mostly involved in DNA or RNA binding/synthesis/modification, or ribosomal proteins. The others were transcription factors, receptors, tumor suppressors, and (proto)oncogenes. Members of these families have already been linked to melanoma. In addition, some of the modulated genes were borne by chromosomes harboring candidate melanoma loci. Comparisons with genes modified in melanoma samples reported in previous studies with similar microarray platform showed that 59% of the known genes sensitive to ultraviolet were modulated in the same way. Furthermore, 39 expressed sequence tags were modulated, and preliminary experiments showed that two expressed sequence tags displayed differential expressions both in melanoma cell lines and in melanoma tumors. These results provide a basis for further studies on the role of modulated genes in ultraviolet-induced melanoma. Because some of these genes are potential markers of the disease, they might help for developing new molecular-based strategies for risk prediction in patients