Decreased long noncoding RNA MIR31HG is correlated with poor prognosis and contributes to cell proliferation in gastric cancer

Long noncoding RNAs (lncRNAs) are emerging as key regulators governing fundamental biological processes, and their disorder expression involves in the development of several human cancers. MIR31HG, an lncRNA located in 9p21.3 and 2166 bp in length, has been found to be upregulated in breast cancer and contributes to cell proliferation and invasion. However, the expression pattern and biological function of MIR31HG in gastric cancer are still not well documented. In this study, we found that MIR31HG expression is decreased in gastric cancer tissues and associated with larger tumor size and advanced pathological stage. Patients with lower MIR31HG expression had a relatively poor prognosis. Furthermore, ectopic over-expression of MIR31HG could inhibit gastric cancer (GC) cell proliferation both in vitro and in vivo, while knockdown of MIR31HG by small interfering RNA (siRNA) promoted cell proliferation in GC cells partly via regulating E2F1 and p21 expression. Our findings present that decreased MIR31HG is involved in GC development and could be identified as a poor prognostic biomarker in GC patients.