MicroRNA-139 inhibits the proliferation, migration and invasion of gastric cancer cells by directly targeting ρ-associated protein kinase 1.

The expression, function and underlying mechanisms of microRNA-139 (miR-139) in gastric cancer were investigated in the present study. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to detect miR-139 expression in gastric cancer tissues and cell lines. The effects of miR-139 overexpression on gastric cancer cell proliferation, migration and invasion were evaluated. ρ-associated protein kinase 1 (ROCK1) was predicted as a downstream target of miR-139 and its role in gastric cancer was assessed by bioinformatics analysis, luciferase reporter assay, RT-qPCR and western blot analysis. ROCK1 overexpression was established to investigate if the effects of miR-139 on gastric cancer cells may be attenuated. The results indicated that miR-139 was aberrantly downregulated in gastric cancer tissues and cell lines. Increased miR-139 expression reduced gastric cancer cell proliferation, migration and invasion. ROCK1 was demonstrated to be a direct target of miR-139 in gastric cancer and ROCK1 overexpression reversed the suppressive effects on gastric cancer cell proliferation, migration and invasion induced by miR-139 overexpression. The present study provides clear evidence demonstrating the anti-oncogenic activity of miR-139 in human gastric cancer, as mediated by the targeted downregulation of ROCK1.