MiR-200 family and cancer: From a meta-analysis view

The role of microRNAs (miRNAs) in cancer development was implicated as oncogene or tumor suppressor. One of the miRNA family, the miR-200 family, was mainly characterized as tumor suppressor. However, controversial results were reported. The associations between miR-200 family (consisting of five miRNAs: miR-141/200a/200b/200c/429) and cancer prognosis were inconsistent. Therefore, we conducted a meta-analysis by searching PubMed and Embase databases for studies assessing the association between the expression of miR-200 family and patients' survival of cancers. Hazard ratios (HRs) with 95% confidence intervals (CIs) were extracted from the studies and pooled HRs was determined to evaluate the association. This meta-analysis comprised 58 articles with 8107 cancer patients. The overall analysis showed that patients with higher expression of miR-200 family were associated with worse survival (HR = 1.206, 95% CI: 1.115-1.305, p < 0.001). In the stratified analysis, high level of miR-200b and miR-200c was associated with poor patients' survival. In the subgroup analysis, expression of miR-200a and miR-429 was associated with survival of breast cancer and liver cancer, respectively. Expression of miR-141 was found to be associated with favorable patients' survival in pancreatic cancer (HR = 0.275, 95% CI: 0.104-0.727, p = 0.009). In the subgroup analysis of sample type of miR-141, reverse associations with patients' survival were found from tissue (HR = 0.769, 95% CI: 0.597-0.990, p = 0.042) and blood (HR = 1.496, 95% CI: 1.183-1.893, p = 0.001). Our findings revealed that association between miR-200 family and prognosis of various cancer types was significant and the results needed specific interpretation.