Original articleMicroRNA-214 promotes peritoneal metastasis through regulating PTEN negatively in gastric cancer

SummaryBackground and objectiveWe aimed to investigate the effects of microRNA-214 (miR-214) on peritoneal metastasis as well as to elucidate its regulatory mechanism in gastric cancer (GC).MethodsThe expression levels of miR-214 in human GC cell lines MKN-28NM, MKN-28M, GC9811 and GC9811-P were analyzed by quantitative real-time PCR. Lentiviral miR-214, lentiviral miR-214 inhibitor, and empty lentiviral vector were transfected to GC cell lines, respectively. The roles of miR-214 in cell invasion, migration, proliferation and colony-forming ability were then analyzed. Besides, the expression levels of PTEN in different transfected cells were determined by western blot analysis.ResultsWe found that miR-214 was up-regulated in GC9811-P cells with high metastatic potential to the peritoneum compared with that in GC9811 cells. In addition, in vitro overexpression of miR-214 promoted cell invasion, migration, proliferation and colony-forming ability of GC9811 cells, while down-regulation of miR-214 had opposite effects in GC9811-P cells. Besides, overexpression of miR-214 in GC9811 cells markedly down-regulated PTEN expression, whereas down-regulation of miR-214 in GC9811-P cells significantly increased PTEN expression.ConclusionsOur findings indicate that miR-214 may promote peritoneal metastasis of GC cells via down-regulation of PTEN, thus leading to the progression of GC.