A functional polymorphism in Pre-miR-146a is associated with susceptibility to gastric cancer in a Chinese population.

MicroRNAs play an important role in regulating gene expression at the post-transcriptional level and are involved in numerous physiological processes. Aberrant expression of MicroRNAs is considered to participate in occurrence and progression of human cancers. A G>C polymorphism, rs2910164, which is located in the sequence of miR-146a precursor, could alter mature miR-146a expression and has been suggested to influence cancer risk. The present study was aimed to investigate whether this polymorphism has effects on susceptibility to gastric cancer in the Chinese population. We genotyped the miR-146a rs2910164 polymorphism using the TaqMan method in a two-stage case-control study comprising a total of 1686 gastric cancer patients and 1895 cancer-free subjects. The logistic regression was used to assess the genetic associations with gastric cancer risk. We found a significant association between rs2910164 polymorphism and increased gastric cancer risk [p = 0.038, odds ratio (OR) = 1.26, 95% confidence interval (CI) = 1.01-1.56; GG vs. CC/CG]. Similar results were observed in a follow-up replication study. Combined data from the two studies generated a more significant association [p = 0.001, OR = 1.27, 95% CI = 1.10-1.46; GG vs. CC/CG]. Besides, the increased risk associated with the rs2910164GG genotype was more evident in younger subjects (OR = 1.51, 95% CI = 1.25-1.81) rather than in older subjects. Our results suggest that the rs2910164 polymorphism in the sequence of miR-146a precursor may influence the susceptibility to gastric cancer in our Chinese population.