MicroRNA-32 functions as a tumor suppressor and directly targets EZH2 in uveal melanoma

MicroRNA-32 (miR-32) has been shown to be dysregulated in some human malignancies and this has been found to be correlated with tumor progression. However, its role in uveal melanoma formation and progression remains largely unknown. Thus, the aim of this study was to explore the expression and function of miR-32 in human uveal melanoma. Using quantitative reverse transcription-polymerase chain reaction, we detected miR-32 expression in uveal melanoma tumor tissues and cell lines. The effects of miR-32 on the biological behavior of uveal melanoma cells were also investigated. Finally, the potential regulatory function of miR-32 on EZH2 expression was confirmed. miR-32 expression levels were significantly downregulated in uveal melanoma samples and cell lines (both P < 0.01). Ectopic expression of miR-32 could inhibit uveal melanoma cell proliferation, migration, and invasion, and promote cell apoptosis in vitro. Further, EZH2 was confirmed as a direct target of miR-32 by using the luciferase reporter assay. These findings indicate that miR-32 may function as a novel tumor suppressor in uveal melanoma and could be a potential therapeutic target for this disease.