Two functional polymorphisms in microRNAs and lung cancer risk: a meta-analysis

MicroRNAs are involved in several biological processes including cell apoptosis and proliferation, stress resistance, and fat metabolism, and act as tumor suppressors by malignant transformation of human cells. The aim of this study was to identify the associations of single nucleotide polymorphisms (SNPs) rs11614913 and rs3746444 with lung cancer risk. In this meta-analysis with 2,219 cases and 2,232 controls for SNP rs11614913 and 1,685 cases and 1,690 controls for SNP rs3746444, we summarized five case-control studies by searching databases of PubMed, EMBASE, and Chinese National Knowledge Infrastructure (CNKI). Lung cancer risk associated with the two SNPs was estimated by odd ratios (ORs) with 95% confidence intervals (CIs). SNP rs11614913 (OR 0.88, 95% CI 0.78-1.00 for TT vs. CT + CC) was found to be potentially associated with a decreased risk of lung cancer. However, we found no association between SNP rs3746444 and lung cancer risk. In the subgroup analysis by ethnicity, a negative association was also observed in Asians for SNP rs11614913, but a nonsignificant association for SNP rs3746444. Our meta-analysis provides evidence for potential protective effects on lung cancer risk associated with SNP rs11614913, particularly in Asian populations. Further, larger studies are necessary to validate the findings.