miRNA-183∼96∼182 regulates melanogenesis, cell proliferation and migration in B16 cells.

Melanoma is a highly invasive malignant skin tumor having high metastatic rate and poor prognosis. The biology of melanoma is controled by miRNAs. The miRNA-183 cluster, which is composed of miRNA-183∼96∼182 genes, plays an important roles in tumor development. In order to investigate the role and action of miRNA-183 cluster in B16 cells, we overexpressed and knocked down miRNA-183 cluster in B16 cells. Using bioinformatics analysis, we predicted that the key framscript factor of melangenic genes. Microphthalmia-associated transcription factor (MITF) is one of the targets of miRNA-183 cluster. The results of Luciferase activity assays confirmed that MITF was targeted by miRNA-183 cluster. Overexpression and knockdown of miRNA-183 cluster in B16 cells resulted in down and up regulation of MITF expression, respectively at both mRNA and protein levels. Furthmore, overexpression and knockdown of the miRNA-183 cluster in B16 cells decreased and increased the expression of mRNA and protein of melangenic genes tyrosinase (TYR), and tyrosinase-related protein 1 (TYRP1), dopachrome-tautomerase (DCT), as well as the production of melanins and eumelanin production, respectively. On the proliferation and migration pathway, overexpression and knockdown of miRNA-183 cluster increased and decreased, respectively the expression of mRNA and protein of mitogen-activated protein kinase 1 (MEK1), extracellular regulated protein kinases1/2 (ERK1/2) and cAMP-responsive-element binding protein (CREB). These results indicated that miRNA-183 cluster regulated melanogenesis in B16 cells as well as cell proliferation and migration by directly targeting MITF through migration pathway.