Clinical significance of serum miR-223, miR-25 and miR-375 in patients with esophageal squamous cell carcinoma

Changes in the expression profiles of microRNAs (miRNAs) have been found in many cancers. The study was aimed to investigate the expression of miR-25, miR-223, and miR-375 in the serum of patients with esophageal squamous cell carcinoma (ESCC) and its effect on survival outcome. We examined the expression levels of miR-25, miR-223, and miR-375 in 20 pairs of ESCC cancer and matched paracancerous tissues, serum samples from 94 healthy volunteers and 194 patients with ESCC using quantitative reverse transcription polymerase chain reaction, and analyzed the relationship between expressions of serum miR-25, miR-223, and miR-375 and ESCC clinicopathological parameters as well as survival. Expressions of miR-25 and miR-223 were significantly increased in ESCC tissues compared with paracancerous tissues (P = 0.008 and 0.009, respectively), whereas the expression of miR-375 was significantly decreased in ESCC tissues compared with paracancerous tissues (P = 0.006). Expressions of serum miR-25 and miR-223 were significantly higher in ESCC patients than those in healthy controls, and, inversely, expression of serum miR-375 was significantly lower in ESCC patients than those in healthy controls (P = 0.007). High expression of serum miR-25 was significantly associated with lymph node metastasis (P = 0.01). Survival analysis showed that high expression of serum miR-223 and low expression of serum miR-375 were associated with poor survival in ESCC patients [hazard ratio (HR) = 1.717, 95 % confidence intervals (CI) 1.139-2.588, P = 0.01; HR = 1.750, 95 % CI 1.111-2.756, P = 0.016, respectively). Furthermore, Patients with high miR-223 and low miR-375 expression had higher risk of death than those with low miR-223 and high miR-375 expression (HR = 3.599, 95 % CI 1.800-7.195, P = 2.92 x 10(-4)). In conclusion, miR-25, miR-223, and miR-375 were abnormally expressed in ESCC tissues and sera. Serum miR-223 and miR-375 are potential prognostic biomarkers for ESCC.