title: Cytochrome P450 2A6 polymorphism in nasopharyngeal carcinoma.
abstract: Nitrosamine has been identified as a carcinogen for nasopharyngeal carcinoma (NPC). Here, we investigated if a nitrosamine metabolizing gene, cytochrome P450 2A6 (CYP2A6) played an important role in NPC development. Relationships between the disease and the CYP2A6 were studied in 74 NPC patients and 137 age-matched healthy controls by using PCR-RFLP assay to distinguish between a wide type allele, *1A, and two mutant alleles, *1B and *4C. Overall, a significant association between CYP2A6 polymorphism and NPC development was observed (P<0.05). Individual with mutant alleles had an increased risk for NPC when compared to those with *1A/*1A (OR=2.37, 95% CI=1.27-4.46). In addition, males who carried mutant alleles of CYP2A6 had a fivefold increased risk for NPC when compared with those who carried *1A/*1A genotype (OR=5.02, 95% CI=1.82-14.14). It is thus suggested that CYP2A6 polymorphism may play a crucial role in NPC susceptibility and it may be used as a risk marker for NPC.
authors.affiliation: Research Division, National Cancer Institute, Bangkok 10400, Thailand.
authors.forename: Danai
authors.initials: D
authors.lastname: Tiwawech
authors.forename: Petcharin
authors.initials: P
authors.lastname: Srivatanakul
authors.forename: Anant
authors.initials: A
authors.lastname: Karalak
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ishida
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics*; D065637:Cytochrome P-450 CYP2A6; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D006899:Mixed Function Oxygenases / Q000235:genetics*; D009303:Nasopharyngeal Neoplasms / Q000201:enzymology* / Q000235:genetics; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D006899:Mixed Function Oxygenases; D001189:Aryl Hydrocarbon Hydroxylases; C585710:CYP2A6 protein, human; D065637:Cytochrome P-450 CYP2A6