miR-145 expression level in tissue predicts prognosis of patients with esophageal squamous cell carcinoma

MicroRNA-145 (miR-145) is commonly down-regulated and has been identified as a tumor-suppressive miRNA in multiple types of cancers, as well as in esophageal squamous cell carcinoma (ESCC). In the present study, the clinical significance and prognostic value were investigated in ESCC.

A total of 126 patients with ESCC who underwent surgery were included in the present study. miR-145 expression was determined using quantitative real-time polymerase chain reaction assay (qRT-PCR) and was further correlated with patients' clinicopathological parameters. Overall survival was estimated by using Kaplan-Meier method, and univariate analysis was conducted by log-rank test. The Cox proportional hazards model was used in the multivariate analysis.

miR-145 expression levels in ESCC tissues were significantly decreased compared with the adjacent normal zones (P < 0.001). We observed that the expression level of miR-145 was positively correlated with the tumor differentiation (P = 0.015), lymph node status (P = 0.007), distant metastasis (P = 0.008), and TNM stage (P = 0.033). ESCC patients with low miR-145 expression level had shorter overall survival than those with high miR-145 expression level (log-rank test, P = 0.032). Furthermore, multivariate Cox regression analysis showed that miR-145 expression level was independent factor in predicting the overall survival of ESCC patients (HR = 1.993, 95% CI: 1.277-8.283, P = 0.023).

Our findings indicated that miR-145 expression may be a useful prognostic marker that could be used for predicting overall survival of patients with ESCC.