Transcriptional profiles in melanocytes from clinically unaffected skin distinguish the neoplastic growth pattern in patients with melanoma

Background It is generally accepted that sunlight may contribute to the development of melanoma. Objectives To analyse gene expression of melanocytes obtained from clinically unaffected skin of patients with melanoma and healthy controls before and after exposure to ultraviolet B radiation. Methods Using GeneChip array technology, the gene expression of melanocytes obtained from the two donor groups was profiled, in order to identify transcriptional differences affecting susceptibility to melanoma. Results The data collected did not show any difference between the expression profiles of melanocytes purified from normal donors and from patients with melanoma that was able to give a statistically significant class separation. However, by means of unsupervised clustering our data could be divided into two main classes. The first class included the transcriptome profiles of melanocytes obtained from skin samples of patients with a vertical growth phase (VGP) melanoma, while the second class included the transcriptome profiles of melanocytes obtained from skin samples of patients with a radial growth phase (RGP) melanoma. Conclusions These data suggest that melanocytes in patients with VGP and RGP melanomas show significant differences in gene expression profiles, which allow us to classify patients with melanoma also from clinically unaffected skin.