Association between the DICER rs1057035 polymorphism and cancer risk: evidence from a meta-analysis of 1,2675 individuals.

BACKGROUND DICER, one of the microRNA (miRNA) biogenesis proteins, is involved in the maturation of miRNAs and is implicated in cancer development and progression. The results from previous epidemiological studies on associations between DICER rs1057035 polymorphism and cancer risk were inconsistent. Thereforewe performed this meta-analysis to summarize possible associations. MATERIALS AND METHODS We searched all relevant articles on associations between DICER rs1057035 polymorphism and cancer risk from PubMed, EMBASE, Chinese Biomedical Literature and Chinese National Knowledge Infrastructure until August 2014. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess any associations. Heterogeneity tests, sensitivity analyses and publication bias assessments were also performed in this meta-analysis. All analyses were conducted using STATA software. RESULTS Seven case-control studies, including 4,875 cancer cases and 7,800 controls were included in the meta-analysis. Overall, the results indicated that the C allele of DICER rs1057035 polymorphism was significantly associated with decreased cancer risk in allelic comparison, heterozygote and dominant genetic models (C vs T: OR=0.88, 95%CI 0.81-0.95, p=0.002; TC vs TT: OR=0.85, 95%CI 0.77-0.93, p=0.001; CC/TC vs TT: OR=0.86, 95%CI 0.78-0.94, p=0.001). In the subgroup analysis by ethnicity, a significantly decreased cancer risk was found in Asian but not Caucasian populations. CONCLUSIONS The present meta-analysis suggests that the C allele of the DICER rs1057035 polymorphism probably decreases cancer risk. However, this association may be Asian-specific and the results should be treated with caution. Further well-designed studies based on larger sample sizes and group of populations are needed to validate these findings.