Down-Regulation of circNRIP1 Promotes the Apoptosis and Inhibits the Migration and Invasion of Gastric Cancer Cells by miR-182/ROCK1 Axis.

Circular RNAs (circRNAs) play important roles in the progression of human cancers. circRNA nuclear receptor interacting protein 1 (circNRIP1) has been reported to play as an oncogene in gastric cancer. However, the mechanism underlying circNRIP1 in gastric cancer progression is far from understood. Forty-five gastric cancer patients were recruited and overall survival of patients was analyzed. Gastric cancer cell lines MGC-803 and AGS cells were cultured for study in vitro. The expression levels of circNRIP1, microRNA (miR)-182 and rho-associated protein kinase 1 (ROCK1) were detected by quantitative real-time polymerase chain reaction or Western blot. Cell migration, invasion, cell cycle distribution and apoptosis were determined by transwell, flow cytometry and Western blot assays, respectively. The target association between miR-182 and circNRIP1 or ROCK1 was assessed by luciferase reporter assay and RNA immunoprecipitation. circNRIP1 expression was enhanced in gastric cancer tissues and cells and high expression of circNRIP1 indicated poor survival of patients. Knockdown of circNRIP1 suppressed cell migration and invasion, arrested cell cycle at G0-G1 phase and promoted apoptosis in gastric cancer cells. miR-182 was a target of circNRIP1 and its deficiency reversed the effect of circNRIP1 silence on cell migration, invasion, cell cycle distribution and apoptosis in gastric cancer cells. Moreover, ROCK1 was validated as a target of miR-182 and competitively regulated by circNRIP1. Silence of circNRIP1 inhibited progression of gastric cancer by increasing miR-182 and decreasing ROCK1, providing a novel target for the treatment of gastric cancer.