Association analysis of genetic variants in microRNA networks and gastric cancer risk in a Chinese Han population

To investigate associations between genetic variants involved in microRNA networks (microRNA biogenesis, microRNA and microRNA binding sites) and risk of gastric cancer. We genotyped 19 SNPs of the microRNA-related genes in a case-control study of 311 gastric cancers and 425 cancer-free controls in a Chinese Han population. We found that two of the SNPs were significantly associated with gastric cancer. Inhibitory effect of minor allele T of rs2071504 SNP within the exon of POLR2A gene was significantly associated with gastric carcinogenesis ( = 0.033, aOR = 0.742, 95%CI = 0.564-0.977) and the SNP rs895819 in the miR-27a gene with the minor allele C presented significantly reduced risk to gastric cancer ( = 0.037, aOR = 0.771, 95%CI = 0.604-0.985). Further stratified analysis with regard to clinical pathological parameters of the patients indicated that the SNP rs2071504 was associated with lymph node metastasis ( = 0.021, aOR = 0.529, 95%CI = 0.307-0.910) and TMN stage ( = 0.021, aOR = 0.532, 95%CI = 0.311-0.908), respectively. Our findings provided evidence that the SNP rs2071504 in the exon of POLR2A gene would not only confer a decreased risk of gastric cancer, but also influence lymph node metastasis and TMN stage of gastric cancer in the Chinese population.