MiR-224 promotes proliferation and migration of gastric cancer cells through targeting PAK4.

Although recent studies have shown the important role and overexpression of miR-224 in several tumors, its function in gastric cancer has not yet been defined. In the present study, we tried to confirm the result of microRNAs microarray and further investigated the functions of miR-224 in gastric cancer, and tried to find new downstream targets of miR-224. In this study, the level of miR-224 was measured in gastric cancer cells with the normal human gastric epithelial cell. The effects of miR-224 of on proliferation, migration, and target protein expression were evaluated by CCK8 assay, colony assay, transwell migration assay, western blotting. In addition, luciferase reporter plasmid was constructed to demonstrate the direct target of miR-224. Overexpression of miR-224 was detected in the gastric cancer cells, especially in SCG-7901. Exogenous miR-224 expression promoted the proliferation and migration of gastric cells and abrogating expression of miR-224 suppressed proliferation, and migration of SCG-7901 cells in vitro. Luciferase assays revealed that miR-224 directly targeted the 3'UTR of p21-activated kinase 4 (PAK4). The present study provides an experimental foundation for miR-224 as a potential tumor suppressor that may decrease PAK4 expression to inhibit gastric cancer cells and that in the future, targeting of this miRNA may provide a novel strategy for the diagnosis and treatment of patients with this lethal disease.