Low miR-133a expression is a predictor of outcome in patients with esophageal squamous cell cancer.

OBJECTIVE: Identification and development of new biomarkers could be beneficial for diagnosis and prognosis of esophageal squamous cell cancer (ESCC) patients. The aim of this study was to examine the clinical significance of miR-133a expression in tissues from ESCC patients.

PATIENTS AND METHODS: Quantitative real-time reverse transcriptive-PCR (qRT-PCR) was performed to examine miR-133a expression levels in 126 ESCC tissues. Survival curves were plotted using the Kaplan-Meier method and differences in survival rates were analyzed using the log-rank test. Univariate and multivariate Cox regression analyses were conducted to determine whether miR-133a was an independent predictor of survival.

RESULTS: We found that the levels of miR-133a in ESCC tissues exhibited lower than that in matched normal tissues (p < 0.01). Low miR-133a expression was positively associated with T stage of ESCC (p = 0.013) and tumor length (p = 0.007). Moreover, low levels of miR-133a was associated with lower overall survival (OS) (p = 0.001) and disease-free survival (DFS) (p = 0.001). According to multivariate analysis, miR-133a level was confirmed to be an independent prognostic factor for worse survival.

CONCLUSIONS: MiR-133a may represent a prognostic biomarker and therapeutic target in esophageal squamous cell cancer prognosis and treatment.