The Prognostic Value of the MiR-200 Family in Colorectal Cancer: A Meta-analysis with 1882 Patients

Background: MicroRNAs are small non-coding RNAs containing 18-22 nucleotides which play a role in RNA silencing and post-transcriptional regulation of their target genes.The MiR-200 family comprises miR-141, miR-200a, miR-200b, miR-200c and miR-429.Increasing evidence indicates that miR-200 microRNAs play a role in cancer metastasis.For example, miR-200 microRNAs were reported to influence the prognosis in colorectal cancer patients by regulating the expression of genes related to the epithelial-mesenchymal transition 6 .Previous studies have shown that the high expression of miR-200 microRNAs has an impact on the overall survival and Relapse-free Survival of CRC patients.However, the study results were inconsistent.Results: Data from a total of 1882 patients from 9 studies was included in the meta-analysis.Poorer Relapse-free Survival (RFS) was observed in patients with high expression levels of miR-200 microRNAs (HR=1.13,95% CI 1.04-1.23).Additionally, subgroup analysis of sample types revealed a significant association between higher expression of the miR-200 family in the plasma and poorer OS (HR=1.23,95% CI 1.08-1.41)and RFS (HR=2.39,95% CI 1.20-4.77),which indicates that the miR-200 family can be used as an easily detectable biomarker for evaluation of the prognosis of patients with colorectal cancer.Conclusions: High expression levels of miR-200 microRNAs were associated with poor clinical outcomes in colorectal cancer patients.The miR-200 family can therefore potentially serve as a prognostic biomarker.Further studies should be performed to verify the clinical utility of the miR-200 family in colorectal cancer.