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

Purpose: To investigate associations between genetic variants involved in microRNA networks (microRNA biogenesis, microRNA and microRNA binding sites) and risk of gastric cancer.

Methods: We genotyped 19 SNPs of the microRNArelated genes in a case–control study of 311 gastric cancers and 425 cancer-free controls in a Chinese Han population.

Results: 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 (p = 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 (p = 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 (p = 0.021, aOR = 0.529, 95%CI = 0.307–0.910) and TMN stage (p = 0.021, aOR = 0.532, 95%CI = 0.311– 0.908), respectively.

Conclusions: 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.