Decreased expression of the long non-coding RNA MLLT4 antisense RNA 1 is a potential biomarker and an indicator of a poor prognosis for gastric cancer

In recent years, the identification of long non-coding RNAs (lncRNAs) led to the analysis of their characteristics in cancer biology. However, the expression of lncRNAs in cancer and their clinical significance remain unclear. In the present study, an investigation of lncRNAs that may be involved in the regulation of metastasis using microarray and polymerase chain reaction analyses resulted in the identification of MLLT4 antisense RNA 1 (MLLT4-AS1) as a significantly downregulated lncRNA in gastric cancer tissue compared with normal adjacent tissue (P=0.006). Furthermore, the downregulation of MLL4-AS1 was significantly associated with advanced Tumor-Node-Metastasis stage (P=0.007) and lymph node metastasis (P=0.008). Cox regression analysis showed that MLLT4-AS1 expression was an independent predictor for overall survival (hazard ratio, 13.136; 95% confidence interval, 5.065-34.068; P<0.001). These data suggest that the decreased expression of MLLT4-AS1 is a potential biomarker and a predictor of a poor prognosis for gastric cancer.