Identification of Increased Tissue microRNA-214 Expression Level as a Potential Prognostic Biomarker for Gastric...

MicroRNAs (miRNAs) have been recognized as important candidates for diagnostic, prognostic, and predictive biomarkers for many human cancer types, including gastric cancer. Previous studies have found that the expression level of miR-214 was increased in gastric cancer tissues, and it was able to promote the proliferation, migration, and invasion of gastric cancer cells. In the present study, we aimed to investigate its clinical significance and prognostic value in gastric cancer.

A total of 133 pairs of gastric cancer tissues and corresponding adjacent normal gastric tissues were obtained from 133 patients diagnosed with gastric cancer. Quantitative real-time PCR (qRT-PCR) assays were carried out to detect the expression level of miR-214. Associations between tissue miR-214 expression level and clinicopathological parameters were evaluated using Chi square test. Overall survival was calculated, and survival curves were plotted using the Kaplan-Meier method; differences between groups were compared using log-rank tests. Multivariate analysis using the Cox proportional hazards regression model was performed to assess the prognostic value of miR-214 expression.

We found that expression level of miR-214 was significantly higher in the gastric cancer tissues than in the adjacent normal gastric tissues (P<0.001). The expression levels were significantly associated with depth of invasion (P=0.022), differentiation degree (P=0.009), lymph node metastasis (P<0.001), and TNM stage (P<0.001). The patients with high miR-214 expression level showed reduced overall five-year survival compared to those with low miR-214 expression (log-rank test P=0.015). Furthermore, multivariate regression analysis showed that tissue miR-214 expression level was an independent prognostic factor overall survival (HR=2.102, 95% CI: 1.572-8.822, P=0.033) in gastric cancer.

Our results indicated that miR-214 was closely related to the occurrence, progression, and metastasis of gastric cancer, and overexpression of miR-214 in tissues might serve as a potential prognostic biomarker for gastric cancer.