Mechanism of miR-137 regulating migration and invasion of melanoma cells by targeting PIK3R3 gene.

Objective: To investigate the effect of microRNA-137 (miR-137) on the migration and invasion of melanoma cells and its mechanism.

Methods: Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of miR-137 in melanoma tissues and cells. miR-137 mimics, phosphoinositide-3-kinase regulatory subunit 3 (PIK3R3) small interfering RNA and corresponding controls were transfected into A375 and WM451 cells by lipofection. The expression of PIK3R3 was examined by qRT-PCR and Western blot analysis. The Trans-well assay was conducted to measure cell migration and invasion. Dual luciferase reporter assay was used to detect the interaction between miR-137 and PIK3R3.

Results: Compared with normal pigmented nevus tissue, miR-137 expression was significantly reduced in melanoma tissues. Compared with keratinous HaCaT cells, the level of miR-137 was significantly decreased in melanoma SK-MEL-1, A375, and WM451 cells. Knockdown of miR-137 significantly reduced the migrated and invasive abilities of melanoma A375 and WM451 cells. Moreover, inhibition of PIK3R3 obviously suppressed the migration and invasion abilities of melanoma A375 and WM451 cells. Luciferase activity assay showed that PIK3R3 was a direct target of miR-137. In addition, overexpression of miR-137-inhibited PIK3R3 expression, while knockdown of miR-137-enhanced PIK3R3 abundance. Restoration of PIK3R3 reversed the regulatory effect of miR-137 on cell migration and invasive in melanoma A375 and WM451 cells.

Conclusion: miR-137 inhibited melanoma cell migration and invasion by targeting PIK3R3 gene.