Impacts of Mir146a Genotypes on Bladder Cancer Risk in Taiwan

The aim of this study was to investigate the association between single-nucleotide polymorphisms (SNPs) in mir146a and mir196a and bladder cancer (BLCA) risk in Taiwan. The genotypes of mir146a rs2910164 and mir196a rs11614913 were determined in 375 BLCA patients and 375 healthy controls using PCR-RFLP methodology, and their associations with BLCA risk were evaluated. The study also measured the serum expression level of mir146a using quantitative RT-PCR. The results showed that the distributions of CC, CG and GG genotypes of mir146a rs2910164 were 31.7%, 45.6% and 22.7% in the control group, and 21.9%, 44.3% and 33.8% in the case group, respectively. In logistic regression analyses, the heterozygous variant genotype CG carriers showed a marginally significant association with increased BLCA risk (OR = 1.41, 95% CI = 0.99–2.01), while the homozygous variant genotype GG carriers had a 2.17-fold increased risk of BLCA (OR = 2.17, 95%CI = 1.46–3.21). Moreover, carriers of the GG/CG genotypes had significantly higher serum levels of mir146a than those with the CC genotype (p < 0.0001), indicating a genotype–phenotype correlation. In contrast, mir196a rs11614913 was not associated with BLCA risk. Therefore, the genotypes of mir146a rs2910164 may serve as a useful biomarker for predicting the risk of BLCA.