Association between miRNA polymorphisms and susceptibility to brain tumors: A meta-analysis

Previous studies have demonstrated that single-nucleotide polymorphisms (SNPs) in miRNAs are related to the susceptibility to brain tumors, but the conclusions remain controversial. This study was to perform a meta-analysis to re-assess the associations between miRNA SNPs and brain tumor risk. Relevant studies were identified in the databases of PubMed and the Cochrane Library databases. Pooled odds ratio (OR) and 95% confidence interval (95% CI) were calculated to assess the relationships between SNPs and the risk of brain tumors under various genetic models by the STATA software. Five studies, containing 2275 cases, and 2323 controls, were included, 4 of which evaluated miR-196a2 (rs11614913), 3 for miR-146a (rs2910164) and 2 for miR-499 (rs3746444) and miR-149 (rs2292832), respectively. The meta-analysis indicated that the GG genotype carriers of miR-146a were more susceptible to brain tumors compared with GC genotype carriers (OR = 1.19, 95%CI = 1.01-1.41, P = .036). No significant associations were observed between the SNPs of other miRNAs and the risk of brain tumors. Furthermore, all miRNA polymorphisms did not show significant associations with the risk of glioma subgroup in any genetic models, while meta-analysis of non-glioma subgroup could not be performed due to low statistical power and analysis of only 1 study. Our study suggests that miR-146a polymorphism may modify the risk for brain tumors, but which type (glioma or benign non-glioma tumors) should be verified with large sample size.