Differentially expressed genes identified in human melanoma cell lines with different metastatic behaviour using high density oligonucleotide arrays.

The increasing incidence of melanoma and the lack of effective treatment, with the exception of tumour excision before the onset of the metastatic phase, make it important to identify genes that may function as new molecular markers for diagnosis and/or prognosis or as new targets for therapy. Recently, a new technique using high density oligonucleotide arrays has been developed to simultaneously screen for the expression of thousands of genes. We used this technique to compare the mRNA expression patterns of two human melanoma cell lines with different metastatic behaviour. Eight differentially expressed genes, namely apolipoprotein CII, tyrosinase-related protein 1, transforming growth factor-beta superfamily, subtilisin-like protein, elongation factor 1 alpha2, alpha2-macroglobulin, human cell division cycle 10 and serine/threonine protein kinase (DYRK1A), were selected to validate the array results by Northern blotting and reverse transcription-polymerase chain reaction (RT-PCR). Furthermore, a reliable correlation between differential expression of these genes in the melanoma cell lines and in fresh lesions of melanocytic tumour progression was demonstrated by RT-PCR analysis. Altogether, our data indicate that high density oligonucleotide arrays are a valuable and reliable tool to screen for differentially expressed genes, and that our study may be considered a basic step in the characterization of genes that are involved in the (malignant) progression of melanoma.