Anti-proliferative role and prognostic implication of miR-141 in gastric cancer

Gastric cancer is a prevalent disease causing a high annual death rate worldwide. Recent studies suggest the pivotal regulatory role of microRNAs in gastric cancer and the aberrant expression of microRNA-141 (miR-141) in gastric cancer cells. This study aims to explore the role and possible mechanism of miR-141 in gastric cancer prognosis and cell proliferation. A total of 30 gastric cancer patients were recruited for miR-141 level detection and a follow up of 115 weeks. Human adenocarcinoma cell line AGS was transfected with miR-141 mimic or inhibitor for cell viability, colony formation and cell cycle assays. A gastric cancer mouse model was constructed by implantation of transfected AGS cells. Insulin-like growth factor 1 receptor (IGF1R) was overexpressed in AGS cells to investigate miR-141 mechanism. Results showed that miR-141 was significantly down-regulated in gastric cancer tissue (P < 0.001). The patients with lower miR-141 levels exhibited poorer prognosis. miR-141 inhibited AGS cell viability (P < 0.01), colony formation (P < 0.01) and cell cycle (P < 0.05), and the mice implanted with miR-141 mimic cells showed an obvious smaller tumor size (P < 0.01), suggesting the anti-proliferative role of miR-141. Both the phosphorylated and total IGF1R protein levels were inhibited by miR-141, while IGF1R overexpression reversed the effects of miR-141 in AGS cell proliferation. These results indicate the potential roles of miR-141 as a prognostic factor and as a therapeutic alternative for gastric cancer. Its mechanism may be associated with IGF1R, and further research is necessary for more detail information.