The Role of MiR-711 in Regulating the Stemness and EMT of Gastric Cancer Stem-Like Cells

Abstract

Background: Cancer stem cells (CSCs) are important factors for metastasis and recurrence. The relationship between miR-711 (small non-coding RNA) and gastric CSCs remains unclear. Thus, this study aimed to analyze the effect of miR-711 on the characteristics of gastric cancer stem cells. Methods: SGC-7901 gastric cancer cells were cultured in serum-free medium and CD44⁺ cells were sorted by magnetic separation. The colony forming ability, the expression of stem cell markers (CD133, Oct4 and Nanog), the cell invasion and migration ability were determined. In addition, the influence of miR-711 transfection was explored. Results: Previous studies have demonstrated that upregulation of miR-711 could inhibit epithelial mesenchymal transition (EMT) of gastric cancer cells. In addition, miR-711 has been proven to down-regulate the expression of Akt. LY294002, a commonly used PI3K inhibitor, was used to analyze the mechanism of miR-711 on gastric cancer stem cells. The RT-PCR assay and western blotting assay showed that LY294002 could decrease the expression of p-PDK1 (S241), p-Akt (T308) and Snail in CD44⁺ SGC-7901 cells transfected with miR-711 mimics. Conclusions: MiR-711 may down-regulate CD44⁺ SGC-7901 gastric CSCs characteristics by inhibiting PI3K/Akt/ Snail signaling pathway. MiR-711 may therefore serve as a new target for tumor therapy.