| Abstract: | Polymerase chain reaction with confronting two-pair primers (PCR-CTPP) is an effective genotyping method for single nucleotide polymorphisms (SNPs) in aspects of reducing time and costs for analysis. So far we have established PCR-CTPP conditions for tens of SNPs, including a triplex genotyping (Kawase et al., 2003). In the present study we report a quadruplex PCR-CTPP to genotype simultaneously four functional polymorphisms of carcinogen-metabolizing enzymes, CYP1A1 Ile462Val, GSTM1 null, GSTT1 null and NQO1 C609T, which were reported that they have significant associations with smoking-related cancers. We applied this method for 475 health check-up examinees to demonstrate the performance. Among the subjects, the genotype frequency of CYP1A1 Ile462Val was 56.8% for Ile/Ile, 38.1% for Ile/Val and 5.1% for Val/Val. The null type frequencies of GSTM1 and GSTT1 were 52.8% and 49.9%, respectively. And the genotype frequency of NQO1 C609T was 41.9% for C/C, 41.3% for C/T and 16.8% for T/T. Their distributions were similar to those reported for Japanese by other studies. To the best of our awareness, this is the first paper that reports the success in quadruplex PCR-CTPP. The applied polymorphisms are useful ones, which would be adopted not only for research purposes, but also for risk assessment of individuals exposed to carcinogenic substances. This convenient genotyping would be applied for cancer prevention especially in Asian Pacific regions, where expensive genotyping methods are hardly available. |
