Association of two common microRNA gene polymorphisms with risk of hepatocellular carcinoma: a meta-analysis

Background: Two single nucleotide polymorphisms (SNPs) in microRNA (miRNA) genes, miR-149 C>T (rs2292832) and miR-499 A>G (rs3746444), may be associated with risk of hepatocellular carcinoma (HCC), but the results remain controversial. Available evidence was meta-analyzed to assess the potential association. Methods: PubMed/Medline, Embase, Web of Science, the Cochrane Library, CBM databases, and Google Scholar were systematically searched, and data from relevant case-control studies were meta-analyzed to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) to assess the association of the SNPs miR-149 C>T and miR-499 A>G with HCC risk. Results: Meta-analysis of 12 studies involving 4,647 cases and 6,282 healthy controls, nearly entirely from Chinese populations, showed that the miR-149 C>T polymorphism was not associated with HCC risk in any genetic model tested: allelic (OR 1.01, 95% CI 0.92 to 1.11, P = 0.82), recessive (OR 1.69, 95% CI 0.85 to 3.38, P = 0.14), dominant (OR 1.06, 95% CI 0.88 to 1.27, P = 0.56) or homozygous (OR 0.76, 95% CI 0.40 to 1.43, P = 0.39). Similarly, the miR-499 A>G polymorphism was not associated with HCC risk in any model tested: allelic (OR 1.15, 95% CI 0.91 to 1.47, P = 0.25), recessive (OR 1.02, 95% CI 0.67 to 1.56, P = 0.93), dominant (OR 0.85, 95% CI 0.65 to 1.10, P = 0.22) or homozygous (OR 1.05, 95% CI 0.65 to 1.68, P = 0.85). Conclusion: Available evidence suggests no significant association of the SNPs miR-149 C>T or miR-499 A>G with HCC risk, at least in Chinese. These results should be verified and extended in studies of other ethnic groups.