Prognostic significance of combined microRNA-206 and CyclinD2 in gastric cancer patients after curative surgery: A retrospective cohort study.

AIM: To investigate associations of microRNA (miR)-206 and CyclinD2 (CCND2) expression, alone or in combination, with clinicopathological characteristics and patients' prognosis in gastric cancer. METHODS: MiR-206 and CCND2 mRNA expression levels were detected by real-time quantitative RT-PCR in 220 self-pairs of gastric cancer and adjacent non-cancerous tissues. RESULTS: Compared with the adjacent non-cancerous tissues, the expression levels of miR-206 and CCND2 mRNA were respectively reduced and elevated in gastric cancer tissues dramatically (both P<0.001). Notably, the expression levels of miR-206 in gastric cancer tissues were negatively correlated with those of CCND2 mRNA significantly (r=-0.463, P<0.001). Then, statistical analysis showed that low miR-206 expression and high CCND2 expression, alone or in combination, were all significantly associated with great depth of invasion, positive lymph node and distant metastases, and advanced TNM stage of human gastric cancer (all P<0.05). After that, we also found that the overall survivals of the patients with low miR-206 expression and high CCND2 expression were respectively shorter than those with high miR-206 expression and low CCND2 expression. More interestingly, miR-206-low/CCND2-high expression was associated with a significantly worst overall survival of all miR-206/CCND2 groups (P<0.001). Furthermore, multivariate analysis identified miR-206 and/or CCND2 expression as independent prognostic factors for overall survival in patients with gastric cancer. CONCLUSION: Our data provide evidence that the dysregulation of miR-206-CCND2 axis may contribute to the aggressive progression and poor prognosis of human gastric cancer in clinical settings. Combined detection of their expression might be particularly helpful for surveillance of disease progression and treatment stratification.