Decreased Serum Exosomal microRNA-134 Expression and Its Prognostic Value in Gastric Cancer

Objective. Identification of reliable biomarkers for the diagnosis and prognosis of gastric cancer (GC) is very important for achieving early cancer detection and improving clinical outcomes. The aim of the present study was to explore the clinical significance of serum exosomal miR-134 in GC. Methods. A total of 133 GC cases were enrolled in this study, and quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) was carried out to measure the relative serum exosomal miR-134 expression level. The association between serum exosomal miR-134 expression and clinicopathological characteristics was investigated. Results. Our results showed that serum exosomal miR-134 expression was significantly lower in GC patients than in controls. In addition, serum exosomal miR-134 discriminated GC cases from healthy controls with high accuracy. Moreover, reduced serum exosomal miR-134 expression was closely associated with aggressive clinical variables including TNM stage, lymph node metastasis and invasion depth. Furthermore, Kaplan-Meier analysis revealed that GC patients with low serum exosomal miR-134 expression tended to have shorter overall survival and relapse free survival. In multivariate analysis, serum exosomal miR-134 was an independent prognostic marker for GC. Conclusion. In conclusion, serum exosomal miR-134 might serve as a promising diagnostic and prognostic biomarker for GC.