miR-186 suppressed CYLD expression and promoted cell proliferation in human melanoma

Previous studies have shown that microRNA-186 (miR-186) is overexpressed in various human cancers and is associated with the regulation of the carcinogenic processes. However, the underlying mechanisms of this microRNA in melanoma remain largely unknown. In the present study, the overexpression of miR-186 was identified in melanoma tissues and melanoma cells compared to the expression of miR-186 in the matched tumor adjacent tissues and normal human epidermal melanocytes. Overexpression of miR-186 promoted the proliferation and anchorage-independent growth of melanoma cells, whereas inhibition of miR-186 reduced this effect. Bioinformatics analysis also revealed cylindromatosis (CYLD), a putative tumor suppressor, to be a potential target of miR-186. Luciferase reporter assays showed that miR-186 directly targeted the 3'-untranslated regions of CYLD messenger RNA. Additional experiments showed that overexpression of miR-186 promoted the proliferation of melanoma cells, which was consistent with the inhibitory effects induced by knockdown of CYLD. In summary, the present study indicated that miRNA-186 plays a crucial role in melanoma growth and its oncogenic effect is mediated chiefly through the direct suppression of CYLD expression.