MicroRNA-650 promotes melanoma metastasis via targeting inhibitor of growth family member 4.

Objective: This study aimed to evaluate the effects of microRNA-650 (miR-650) on melanoma metastasis and reveal the regulatory relationship between miR-650 and the inhibitor of growth family member 4 (ING4). Methods: miR-650 expression was determined in human melanoma WM115 and A-375 cells. WM115 cells were transfected with miR-650 mimic or mimic control. The invasion and migration abilities of transfected WM115 cells were analyzed using Transwell and wound healing assays, respectively. Then, miR-650-overexpression lentivirus vector was constructed and transfected into WM115 cells. After injection into the mice, the number of micro-metastatic foci in the lung tissues was counted. A regulatory relationship between miR-650 and ING4 was identified in WM115 and A-375 cells. Results: The miR-650 expression was upregulated in WM115 and A-375 cells. WM115 cells transfected with the miR-650 mimic exhibited higher invasive and migratory abilities than mock cells or cells transfected with negative control (NC). The number of micro-metastatic foci was significantly higher in mice injected with Lenti-miR-650 than that in those injected with mock or NC controls. Transfection with miR-650 mimic observably inhibited the expression of ING4 in WM115 and A-375 cells, whereas transfection with miR-650 inhibitor had the opposite effect. Dual-luciferase reporter gene assay showed that the miR-650 mimic inhibited the luciferase activity of ING4. Conclusion: miR-650 promotes melanoma metastasis by downregulating ING4 expression.