Effects of common polymorphisms in miR-146a and miR-196a2 on lung cancer susceptibility: a meta-analysis

Background: MicroRNAs (miRNAs) may play an important role in organ development, cell differentiation, apoptosis, proliferation, cell growth regulation and act as tumor suppressor genes or proto-oncogenes. Single nucleotide polymorphisms (SNPs) in miRNAs are considered to be genetic factors to influence the susceptibility to lung cancer (LC). Rs2910164 in miR-146a and rs11614913 in miR-196a2 are shown to be associated with increased/decreased LC risk. The aim of this meta-analysis was to systematically summarize the possible association. Methods: The relevant articles were retrieved from several important databases. Studies were selected using specific inclusion and exclusion criteria. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the strength of association between miRNA polymorphism and susceptibility to LC. All analyses were performed using the Stata software. Results: Seven studies were included in this meta-analysis. There were 3,225 cases and 3,268 controls for SNP rs2910164 and 2,794 cases and 2,840 controls for SNP rs11614913. The significant associations between SNP rs2910164 and LC risk were observed (CC vs. GG: OR = 1.30, 95% CI: 1.13-1.50; CC + GC vs. GG: OR = 1.15, 95% CI: 1.02-1.29; CC vs. GC + GG: OR = 1.27, 95% CI: 1.13-1.42; C vs. G: OR = 1.15, 95% CI: 1.08-1.24). SNP rs11614913 was found to be associated with LC risk in most genetic models (TC vs. TT: OR = 1.16, 95% CI: 1.02-1.32; CC vs. TT: OR = 1.24, 95% CI: 1.06-1.44; CC + TC vs. TT: OR = 1.19, 95% CI: 1.06-1.34; C vs. T: OR = 1.11, 95% CI: 1.03-1.20). In the subgroup analysis by ethnicity, genotyping method and control characteristics, significantly affected LC risks were also suggested. Conclusions: The rs2910164 in miR-146a and the rs11614913 in miR-196a2 are likely to be associated with LC risks.