Effects of microRNA-877 on proliferation and invasion of gastric cancer cells

Objective To investigate the effects of microRNA (miRNA, miR)-877 on proliferation and invasion of SGC7901 gastric cancer cells. Methods The relative expression level of miR-877 in gastric cancer cell lines (SGC7901, MGC803, MKN-45, BSG823, HGC-27, AGS) and normal gastric cell line (GES-1) were measured by real-time quantitative polymerase chain reaction (Real-time PCR). MiR-877 agonist (miR-877 mimics) was synthesized. MiR-877 mimics and miR-877 negative control were transfected into SGC7901 cells by liposome Lipofectamine™ 2000. Cell proliferation ability was detected by cell counting kit-8 (CCK-8) assay. Cell invasion ability was evaluated by Transwell method. The expression of phosphatidylinositol-3-kinase (PI3K), protein kinase B (PKB, also called Akt), phosphorylated Akt (p-Akt) were detected by Western blotting. Results The relative expression level of miR-877 was significantly lower in gastric cancer cell lines SGC7901 (0.21±0.05), MGC803 (0.63±0.11), MKN-45 (0.35±0.07), BSG823 (0.49±0.08), HGC-27 (0.75±0.10), AGS (0.43±0.07) than that in GSE-1 cells (1.09±0.13, all P<0.05). The relative expression level of miR-877 in miR-877 mimics group (0.27±0.05) was significantly lower than that in negative control group (1.06±0.11, t=11.690, P<0.01). The results of CCK-8 assay showed that the absorbance value of miR-877 mimics group (1.59±0.09) was significantly lower than that of negative control group (2.28±0.11, t=4.746, P<0.01) after culturing 72 h. The results of Transwell assay revealed that cell invasion number in miR-877 mimics group (43.60±17.30) was significantly lower than that in negative control group (129.35±16.70, t=8.148, P<0.01). The results of Western blotting manifested that the expression level of PI3K, Akt, p-Akt in miR-877 mimics group were significantly lower than that in negative control group (all P<0.01). Conclusion MiR-877 could inhibit the proliferation and invasion of gastric cancer cells, which is involved in suppressing PI3K/AKt signaling pathway. Key words: Gastric cancer; MicroRNA-877; Proliferation; Invasion; Phosphatidylinositol-3-kinase/protein kinase B signaling pathway