Investigative role of pre-microRNAs in bladder cancer patients: a case-control study in North India.

MicroRNAs (miRNA) are a class of small noncoding RNA molecules that have been implicated in a wide variety of cellular functions through post-transcriptional regulations on target genes. Common genetic variants (single-nucleotide polymorphisms, SNPs) in pre-miRNA genes may alter their expression and/or maturation effecting thousands of target mRNAs, resulting in varied functional consequences. Three common SNPs (hsa-mir-146a G>C rs2910164, hsa-mir-196a2 C>T rs11614913, and hsa-mir-499 T>C rs3746444) in pre-miRNAs were investigated to evaluate their association with urinary bladder cancer risk. The hospital-based case-control study comprised of 212 histologically confirmed patients with urinary bladder cancer and 250 healthy controls who were unrelated, of similar ethnicity, and age and gender matched. Genotyping was done using polymerase chain reaction-restriction fragment length polymorphism methodology. Our results showed that the heterozygous genotype of rs11614913 was higher in cases than controls but the results were marginally significant (p = 0.055; odds ratio, 1.44). Smoking had no impact in modulating the effect of any of the three miRNA SNPs studied. No association was observed with either the tumor stage or grade in patients with bladder cancer. Even though there was no association between the individuals carrying the variant genotypes of the three miRNA studied and bladder cancer risk, marginal significance of heterozygousity in rs11614913 suggested further characterization of miRNA SNPs in a large cohort of varied ethnicity. This could further provide new prospects for understanding the underlying mechanisms between miRNAs and disease etiology.