MiRNA-27a promotes the proliferation and invasion of human gastric cancer MGC803 cells by targeting SFRP1 via Wnt/β-catenin signaling pathway.

This study aims to elucidate the effects of microRNA-27a (miR-27a) on the proliferation and invasion of gastric cancer (GC) cells by targeting SFRP1 via Wnt/β-catenin signaling pathway. GC and normal adjacent tissues were collected from 273 GC patients. Human gastric cancer cell line (MGC803) and normal human gastric mucosal cell line (GES-1) were cultured. The miR-27a mRNA expression was analyzed using Quantitative real-time polymerase chain reaction (qRT-PCR). Immunohistochemistry (IHC) test was used to detect miR-27a and SFRP1 protein expressions. After transfection, cells were divided into five groups: the negative control (NC) group, the miR-27a inhibitor group, the miR-27a mimics group, the miR-27a inhibitor + SFRP1 siRNA group and the miR-27a mimics + SFRP1 overexpression group. Western blotting was conducted to test SFRP1 and Wnt/β-catenin protein expression. Analysis for the target gene of miR-27a was performed using Luciferase assay. Cell proliferation, migration and invasion were determined by CCK8 and Transwell assay. The dual-luciferase reporter assay system was applied to analyze the effects of miR-27a on Wnt/β-catenin signaling pathway. In GC tissue and cell line, miR-27a protein and mRNA expressions were up-regulated, and SFRP1 protein and mRNA expressions were down-regulated. Luciferase assay indicated that miR-27a might target SFRP1 and regulate its expressions. When miR-27a was down-regulated, SFRP1 was up-regulated, and β-catenin, Wnt, p-β-catenin, and p-Wnt were significantly down-regulated. Compared with the NC group, the proliferation, migration and invasion of GC cells were remarkably increased in the miR-27a group, but these were declined in the miR-27a mimics + SFRP1 overexpression group. The proliferation, migration and invasion of GC cells were elevated in the miR-27a inhibitor + SFRP1 siRNA group compared with the miR-27a inhibitor group. These results showed that miR-27a was highly expressed in GC tissues and cells, and it might promote cell proliferation, migration and invasion by targeting SFRP1 via the activation of Wnt/β-catenin signaling pathway.