Common genetic variants in pre-microRNAs and risk of gallbladder cancer in North Indian population.

MicroRNAs (miRNAs) are small, non-coding RNA molecules that function as negative regulators of gene expression. Common genetic variants (single nucleotide polymorphisms, SNPs) in miRNA genes may alter their expression or maturation resulting in varied functional consequences. Present case-control study evaluated the potential association of three SNPs (rs2910164, rs11614913 and rs3746444) in pre-miRNAs with gallbladder cancer (GBC) risk in 230 GBC cases and 230 controls in a North Indian population. Odds ratio (OR) and 95% confidence interval (95% CI) were calculated for the association of individual SNPs and their interactions with GBC. A non-significant increased risk was observed between carriers of variant genotypes of rs2910164, rs11614913 and rs3746444 (ORs=1.3, 1.3 and 1.1, respectively). This increased risk was more profound in GBC patients with gallstones (ORs=1.4, 1.6 and 1.1, respectively). To further evaluate the cumulative effects of the variant allele, we did a combined unfavorable genotype analysis, which showed a borderline statistical significance. In comparison with the low-risk group (0-2 variant alleles), the high-risk group (>2 variant alleles) had a 1.7-fold (95% CI=1.0-2.8) increased risk for GBC (P(trend)=0.056). These findings suggest, for the first time, that common miRNA variants may not contribute to GBC susceptibility in North Indian population.