MiR-129-5p is down-regulated and involved in migration and invasion of gastric cancer cells by targeting interleukin-8

Abstract

Expression of microRNA-129-5p (miR-129-5p) has been reported to decrease in gastric cancer (GC). However,little information is available about how miR-129-5p affects cell migration and invasion of GC. Cancer samples and matched non-tumor adjacent tissues were obtained from patients with GC. Besides,peripheral blood samples were collected from both the patients and healthy volunteers. Expression of miR-129-5p was analyzed by real-time PCR (RT-PCR). After transfection with miR- 129-5p mimics,miR-129-5p inhibitor,or negative controls in human GC cell line SGC-7901,cell viability,colony-formation ability,migration,and invasion assay were evaluated. Luciferase reporter assay,RT-PCR,and enzyme-linked immunosorbent assay (ELISA) were performed to explore whether interleukin-8 was a target of miR-129-5p. Further,small interfering RNA (siRNA) against IL-8 was transfected into cells,and then the effects of miR-129-5p inhibitor on migration and invasion were assessed. MiR-129-5p was down-regulated in both GC samples and blood samples compared to their matched non-tumor adjacent tissues and healthy volunteers (both P < 0.05). Compared to the control group,transfection with miR-129-5p inhibitor markedly increased the cell viability,colony-forming ability,and numbers of migrated and invaded cells. Luciferase reporter assay confirmed that IL-8 was a direct target of miR-129-5p,and IL-8 was negatively regulated by miR-129-5p. Cotransfection of miR-129-5p inhibitor with si-IL-8 reversed the effect of miR-129-5p inhibitor on the migration and invasion of the cells. MiR-129-5p and regulates migration and invasion of GC cells by targeting IL-8.