Gene Expression Profiling of Melanocytes following Q-Switched Ruby Laser Irradiation

Abstract

Background: The Q-switched Ruby laser (QSRL) is used for the treatment of pigmented lesions. The influence of QSRL treatment on gene expression of nontransformed primary melanocytes has not been addressed in vitro. Objective: We investigated the gene expression profile of melanocytes following QSRL irradiation. Methods: Primary melanocytes were irradiated with the QSRL (694 nm). Early and late transcriptional effects were analyzed using the Affymetrix gene array platform. Results: Laser irradiation of melanocytes had minor effects on mRNA expression. We found only 31 out of 14,500 genes which were at least twofold up- or downregulated. The differential expression of heme oxygenase 1 and galanin in QSRL-treated melanocytes was additionally confirmed by real-time RT-PCR. Analysis of a selection of 36 genes which are known to be associated with malignant melanoma development and progression revealed no significantly aberrant expression in the QSRL-treated melanocytes. Conclusion: Our study shows that QSRL treatment of primary melanocytes in vitro does not cause major alterations of global gene expression and particularly of genes associated with malignant melanoma. However, since QSRL treatment may have different effects on gene expression of melanocytic cells in vivo, further studies are required to evaluate QSRL treatment of (nevo-) melanocytic lesions.