Association of the miR-196a2 C>T and miR-499 A>G polymorphisms with hepatitis B virus-related hepatocellular carcinoma risk: an updated meta-analysis.

BACKGROUND This study meta-analyzed data on the possible association of the miR-196a2 C>T (rs11614913) and miR-499 A>G (rs3746444) polymorphisms with risk of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). METHODS Databases in PubMed, EMBASE, Web of Science, China BioMedicine, and Google Scholar were systematically searched to identify relevant studies. Meta-analyses were performed to examine the association of the miR-196a2 C>T and miR-499 A>G polymorphisms with HBV-related HCC risk. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. RESULTS A total of 13 studies involving 3,964 cases and 5,875 healthy controls were included. Random-effect meta-analysis showed that the T allele and TT genotype of miR-196a2 C>T were associated with significantly lower HBV-related HCC risk (allelic model, OR =0.84, 95% CI =0.71-0.99, P=0.04; homozygous model, OR =0.68, 95% CI =0.47-0.98, P=0.04). In contrast, miR-499 A>G showed no significant association with HBV-related HCC risk in either overall pooled analysis or ethnic subgroup analysis according to any of the four genetic models. Based on analysis of ethnic subgroups, neither miR-196a2 C>T nor miR-499 A>G was significantly associated with risk of HBV-related HCC in Chinese population. CONCLUSION The polymorphism miR-196a2 C>T, but not miR-499 A>G, may be associated with decreased HBV-related HCC risk. These conclusions should be verified in large, well-designed studies.