Correlation between miRNA-196a2 and miRNA-499 polymorphisms and bladder cancer

MicroRNA (miRNA) polymorphisms are closely associated with cancers. This study explored the correlation between miRNA-196a2 rs11614913 and miRNA-499 rs3746444 polymorphisms and the occurrence and pathological features of bladder cancer. The case group consisted of 372 patients with bladder cancer, and the control group consisted of 372 healthy volunteers. Massarray system was used to detect single nucleotide polymorphisms (SNPs) at miRNA-499 rs3746444 and miRNA-196a2 rs11614913 sites in the two groups. Correlation between SNPs at these two sites in miRNA and the occurrence and pathological features of bladder cancer was assessed using logistic regression analysis. Genotype frequencies at rs11614913 site showed significant difference between the two groups (chi(2)=18.586, P<0.001). The frequency of TT genotype in the case group (18.38%) was significantly lower than that of the control group (33.35%) (P<0.05). The risk of bladder cancer among carriers of TT genotype was 0.57 times of that among carriers of CC genotype (ORadjusted=0.57, 95% CI: 0.41 similar to 0.85). The frequency of the genotype at rs3746444 site was not significantly different between the two groups (chi(2)=5.107, P=0.078)). However, the frequency of GG genotype in bladder patients (7.96%) was much higher than that of the controls (3.51%) (P<0.05). The risk of bladder cancer in carriers of GG genotype was 2.33 times of that among the carriers of AA genotype (ORadjusted=2.33, 95% CI: 1.15 similar to 5.12). The genotype frequency at rs11614913 and rs3746444 sites did not vary significantly with tumor staging, adjacent and distant lymph node metastasis (P>0.05). For patients showing different differentiation degree, the genotype frequency at these two sites differed significantly (rs11614913: chi(2)=18.586, P=0.005; rs3746444: chi(2)=11.120, P=0.025). Polymorphisms at miRNA-499 rs3746444 and miRNA-196a2 rs11614913 sites were correlated with the risk of bladder cancer as well as the differentiation degree of the cancer.