The allelic distribution of a single nucleotide polymorphism in the PDCD5 gene locus of Japanese non-small cell lung cancer patients

It has been reported that the rs1862214 single nucleotide polymorphism (SNP) in the programmed cell death 5 gene (PDCD5) is associated with smoking-related lung cancer risk and prognosis in a European population with a history of smoking. The aim of this study was to investigate the status and impact of SNPs in the PDCD5 locus of a Japanese population. We developed an assay based on real-time PCR with melting curve analysis for determining the rs1862214 SNP, and examined this SNP in 165 lung cancer patients and 180 healthy volunteers. Of the 165 lung cancer patients (107 smokers), 25 (17), 72 (47) and 68 (43) had the CC, CG and GG genotypes of rs1862214, respectively. Of the 180 volunteers (117 smokers), 31 (24), 81 (52) and 68 (41) had the CC, CG and GG genotypes of rs1862214, respectively. No significant difference in allelic distribution was found between Japanese patients and healthy controls, even among smokers. Based on the published data, the distribution of this SNP appears to be significantly different in Japanese and European populations. No significant difference in prognosis according to the SNP was observed, either in patients with a history of smoking or in the total number of patients. This too differs from the results from a European population. In conclusion, we developed a convenient real-time PCR-based assay for the genotyping of rs1862214 in the PDCD5 locus. The distribution of the rs1862214 SNP in our Japanese population differs from its distribution in a European population, and is not related to the risk of cancer or to poor prognosis in lung cancer. This suggests the presence of an ethnicity-related difference in the role of PDCD5 in the pathogenesis of lung cancer.