ABSTRACT
Objective:To investigate the relationship between the expression of serum exsomal miRNA-155-5p (miR-155-5p) and prognosis in patients with esophageal squamous cell carcinoma (ESCC).Methods:A total of 336 samples from ESCC patients in Fujian Provincial Cancer Hospital from October 2014 to December 2015 were collected. The relative expression levels of serum exsomal miR-155-5p were detected by using real-time fluorescent quantitative polymerase chain reaction (qRT-PCR). Cut-off value of the expression levels of serum exsomal miR-155-5p was determined by using X-tile software. Based on the optimal cut-off value, patients were divided into miR-155-5p low expression group and miR-155-5p high expression group. The survival curve was drawn by using Kaplan-Meier method and Cox proportional hazards regression model was used to make survival analysis.Results:The cut-off value of serum exsomal miR-155-5p expression level was 2.340. According to the cut-off value, patients were divided into miR-155-5p low expression group (<2.340) of 51 cases and miR-155-5p high expression group (≥2.340) of 285 cases. There were no statistical differences in age ( χ2 = 0.020, P = 0.887), gender ( χ2 = 0.283, P = 0.595), tumor location ( χ2 = 0.063, P = 0.977), differentiation grade ( P = 0.474), clinical staging ( χ2 = 3.996, P = 0.136) and surgery treatment ( χ2 = 0.941, P = 0.332) of patients in both groups. ESCC patients in serum exsomal miR-155-5p high expression had a higher risk of death compared with patients in miR-155-5p low expression group ( HR = 1.763, 95% CI 1.049-2.961, P = 0.032). Conclusion:The high expression level of serum exsomal miR-155-5p is associated with poor prognosis in ESCC patients and it could be used as a prognostic new marker in ESCC patients.