Toxicity of miR-204-5p Inhibition for Melanoma B16 Cells in vitro and Mice in vivo

MiR-204-5p is an oncosuppressive microRNA the level of which diminishes in various cancer types. The aim of this study was to evaluate miR-204-5p inhibition of melanoma-cell viability, as well as to determine whether miR-204-5p transfection of melanoma B16 cells with miR-204-5p mimic/inhibitor affected the microRNA expression. Proliferation of transfected cells was slightly, probably nonspecifically, reduced after 96 h. LNA™ inhibitors produced toxic effects in vivo. miR-204-5p-mimic/inhibitor application resulted to a slight, most likely nonspecific, modulation of melanoma-cell proliferation after 96 h. Bioinformatic analysis revealed that miR-204-5p is involved in the estrogen signaling pathway, lysine degradation, signaling pathways regulating pluripotency of stem cells, melanogenesis, transcriptional deregulation in cancer. Injection of miR-204-5p LNA™ inhibitor into mice reduced the level pf miR-204-5p but was not toxic.