DIFFERENTIAL EXPRESSION PROFILES OF MICRORNAS INVOLVED IN MALIGNANT MELANOCYTE PIGMENTATION
Pigmentation as well as pigmentation-associated genes have been recently correlated with poor clinical outcome of metastatic melanoma patients. MicroRNA regulation of melanogenic genes emerges as an alternative mechanism controlling pigmentation. In our study, we have identified and compared miRNA expression profiles in different melanoma cell lines before and after stimulation of pigmentation. The latter was achieved using different mechanisms: by tyrosine, the melanogenesis main substrate, by vemurafenib, a mutated BRAF inhibitor that moderates excessive degradation of MITF, and by forskolin, a stimulator of cAMP pathway. We could identify a series of highly downregulated miRNAs and another of upregulated ones having potential target involved in pigmentation as revealed by in silico analyses. Our study pointed out miRNAs that target CREB and MITF, the main genes activating pigment formation, and, interestingly, others implicated in melanosome transport, bringing new insights into the understanding of the regulation of pigmentation in melanoma and possibly in melanocytes