RESUMO
Although tobacco smoke has been established as a main risk factor in the development of head and neck squamous cell cancer (HNSCC), genetic polymorphisms of xenobiotic metabolizing enzymes are supposed to modulate an individual's susceptibility to smoking-related HNSCC. N-acetyltransferase (NAT) 1 gene is known to be polymorphic and its protein product is implicated in the activation and detoxification of carcinogens, such as aromatic amines, present in tobacco smoke. We developed a rapid and reproducible LightCycler-assisted real-time polymerase chain reaction (PCR) for NAT1 genotyping, which allowed the parallel differentiation of NAT1*3, *4, *10 and *11 alleles and separately of NAT1*14 and *17 alleles within 60 min without the need for further post-PCR processing. In order to investigate the role of the NAT1 gene polymorphism as a risk-modifying factor in HNSCC, we tested for the presence of NAT1*3, *4, *10, *11, *14 and *17 alleles in a case-control study of 291 HNSCC patients and 300 healthy controls of Caucasian origin. Our findings suggest that in Caucasians, the risk of HNSCC is not associated with NAT1 polymorphism. The overall distribution of NAT1 allele frequencies was not significantly different among cases and controls. The presence of the fast acetylator NAT1*10 and NAT1*11 alleles did not significantly increase the risk of HNSCC and no modifying effect of NAT1*10 was observed among smokers. This new approach in NAT1 genotyping substantially increases throughput of sample analysis and, therefore, enhances opportunities to study NAT1 as a risk factor in different cancers in large-scale studies.