Prognostic Significance of MiR-34a Expression in Patients with Gastric Cancer after Radical Gastrectomy

BACKGROUND MiR-34a dysregulation has been implicated in tumorigenesis and progression of gastric cancer, but its role in prognosis of patients with gastric cancer remains unknown. The aim of this study was to investigate the expression and prognostic significance of miR-34a in gastric cancer patients after radical gastrectomy. METHODS Quantitative real-time polymerase chain reaction was performed to detect the expression of miR-34a in human gastric cancer cell lines and tissues in 76 patients with gastric adenocarcinoma from China. Results are assessed for association with clinical features and overall survival (OS) using Kaplan-Meier analysis. Prognostic values of miR-34a expression and clinical outcomes were evaluated by Cox regression analysis. A molecular prognostic stratification scheme incorporating miR-34a expression was determined using receiver operating characteristic analysis. RESULTS The results show that the expression level of miR-34a was decreased in human gastric cancer cell lines and tissues, and down-regulated expression of miR-34a was associated with Lauren classification (P = 0.034). Decreased miR-34a expression in gastric cancer tissues was positively correlated with poor OS of gastric cancer patients (P = 0.013). Further multivariate Cox regression analysis suggested that miR-34a expression was an independent prognostic indicator for gastric cancer (P = 0.027). Applying the prognostic value of miR-34a expression to tumor node metastasis (TNM) stage system showed a better prognostic value in patients with gastric cancer than miR-34a expression (P = 0.0435) or TNM stage (P = 0.0249) alone. CONCLUSION The results reinforce the critical role for the down-regulated miR-34a expression in gastric cancer and suggest that miR-34a could be a prognostic indicator for this disease.