Down-regulation of miR-200c associates with poor prognosis of oral squamous cell carcinoma.

BACKGROUND: MicroRNAs (miRNAs) are considered as promising cancer biomarkers. The aim of the present study is to investigate the prognostic significance of miR-200c in patients with oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: Quantitative real-time PCR (qRT-PCR) was used to determine the expression levels of miR-200c in 204 pairs of OSCC and adjacent noncancerous. Correlations between miR-200c expression levels and clinicopathological characteristics were investigated. Survival analysis was performed using the Kaplan-Meier method and log-rank test. Multivariate analysis of the prognostic factors was performed with a Cox proportional hazards regression model. RESULTS: The expression of miR-200c was significantly down-regulated in OSCC tissues compared with adjacent non-tumor tissues (p < 0.0001). Low expression of miR-200c in tumor tissues was significantly correlated with the positive N classification (p = 0.013), advanced TNM stage (p = 0.007) and poor differentiation grade (p = 0.026). Lower miR-200c expression in patients was significantly associated with poor recurrence-free survival (RFS, p = 0.0003) and overall survival (OS, p = 0.0026). Multivariate analysis confirmed that low miR-200c expression was an independent predictor for poor RFS (hazard ratio (HR) 1.705, 95% CI 1.136-2.56, p = 0.01) and OS (HR 1.669, 95% CI 1.03-2.703, p = 0.037) in patients with OSCC. CONCLUSION: Our results suggest that the miR-200c might be a potential prognostic biomarker for OSCC.