RESUMEN
Objective Recent evidence points towards a close relationship between dysregulation of long non-coding RNA (lncRNA) and carcinogenesis and progression of various tumors including gastric cancer. The aim of this study was to investigate the expression of lncRNA DGCR5 in the gastric cancer tissue and plasma and its influence on the biological behavior of gastric cancer cells. Methods We collected tumorous and adjacent normal tissues from 96 gastric adenocarcinoma patients as well as plasma samples from 34 gastric cancer patients and another 34 healthy controls. We deter-mined the expression of DGCR5 by real-time fluorescent quantitative PCR,analyzed its correlation with the clinicopathological features of gastric cancer,observed the apoptosis, proliferation and invasiveness of the gastric cancer cells after overexpressing DGCR5, and detected the expressions of epithelial-mesenchymal transition (EMT)-associat-ed genes and proteins by Western blot. Results The expression of DGCR5 was significantly decreased in tumor tissue of the gastric canc-er patients as compared with that in the adjacent normal tissue,which was correlated with the advanced TNM stage and lymph node metastasis, and so was it in the plasma of the patients, which was also correlated with the TNM stage. The area under the ROC curve for the diagnosis of gastric cancer by the expression level of plasma DGCR5 was 0.722. Overexpressed DGCR5 induced significant apoptosis and inhibited the proliferation and invasion of gastric cancer cells,markedly promoted the expression of E-cadherin,and suppressed the expressions of N-cadherin,vimentin and Twist. Conclu-sion The expression of DGCR5 is significantly decreased in the tumor tissue and plasma of gastric cancer patients. The DGCR5 level in the plasma has a certain diagnostic value for gastric cancer. Overexpressed DGCR5 can reduce the proliferation and invasiveness of gastric cancer cells,increase their apoptosis,and inhibit EMT.