Background: To date, many studies have reported that microRNAs participate in human carcinogenesis as tumor suppressors or oncogenes and may play important roles as prognostic biomarkers of cancer. The aim of this metaanalysis was to assess the prognostic value of circulating miR-125 in human malignant neoplasms by summarizing the results from all available studies.
Methods: A systematic literature review was carried out using PubMed and Embase. We extracted and estimated the hazard ratios (HRs) for overall survival, which enabled comparison of the high and low expression levels of miR-125 in patients included in the available studies. The analysis was carried out using Stata version 12.0.
Results: A total of 15 articles including 1,606 patients were included in this meta-analysis. For overall survival, the pooled HR of higher miR-125 expression in human malignant neoplasms was 0.90 (95% confidence interval [CI]: 0.58 - 1.38, p = 0.000). Subgroup analysis showed that higher miR-125a expression may predict better survival in patients with cancer (HR = 0.56, 95% CI: 0.41 - 0.76, p = 0.226). However, higher miR-125b expression may predict poorer survival in colorectal cancer (HR = 2.32, 95% CI: 1.35 - 3.99, p = 0.513), non-small cell lung cancer (HR = 2.33, 95% CI: 1.78 - 3.03, p = 0.519), and prostate cancer (HR = 1.60, 95% CI: 1.01 - 2.54, p = 0.292), but better survival in hepatocellular carcinoma (HR = 0.52, 95% CI: 0.34 - 0.81, p = 0.696).
Conclusions: These results suggest that different members of the miR-125 family may have different functions in various cancers. Furthermore, miR-125a or miR-125b may be important clinical prognostic biomarkers for cancer patients.