title: Association between Glucuronidation Genotypes and Urinary NNAL Metabolic Phenotypes in Smokers.
abstract: The most abundant and potent carcinogenic tobacco-specific nitrosamine in tobacco and tobacco smoke is 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). In vivo, NNK is rapidly metabolized to both the (R)- and (S)-enantiomers of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), which possesses similar carcinogenic properties as NNK. The major detoxification pathway for both NNAL enantiomers is glucuronidation by UDP-glucuronosyltransferase (UGT) enzymes including UGT2B10 and UGT2B17. The goal of the present study was to directly examine the role of UGT genotypes on urinary levels of NNAL glucuronides in smokers.
  
  
  
  NNAL-N-Gluc, (R)-NNAL-O-Gluc, (S)-NNAL-O-Gluc, and free NNAL were simultaneously and directly quantified in the urine of smokers by LC/MS analysis. Genotypes were determined by TaqMan assay using genomic DNA.
  
  
  
  The functional knockout polymorphism in the UGT2B10 gene at codon 67 (Asp>Tyr) was significantly (P < 0.0001) associated with a 93% decrease in creatinine-adjusted NNAL-N-Gluc. The polymorphic whole-gene deletion of the UGT2B17 gene was associated with significant (P = 0.0048) decreases in the levels of creatinine-adjusted (R)-NNAL-O-Gluc, with a 32% decrease in the levels of urinary (R)-NNAL-O-Gluc/(S)-NNAL-O-Gluc among subjects with the UGT2B17 (*2/*2) genotype as compared to subjects with the UGT2B17 (*1/*1) genotype.
  
  
  
  These results suggest that functional polymorphisms in UGT2B10 and UGT2B17 are associated with a reduced detoxification capacity against NNAL and may therefore affect individual cancer risk upon exposure to tobacco.
  
  
  
  This is the first report to clearly demonstrate strong genotype-phenotype associations between both the UGT2B10 codon 67 Asp<Tyr genotype and urinary NNAL-N-Gluc levels and between the UGT2B17 copy number variant and urinary (R)-NNAL-O-Gluc levels in smokers. Cancer Epidemiol Biomarkers Prev; 25(7); 1175-84. ©2016 AACR.
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, Washington State University, Spokane WA 99210.
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, Washington State University, Spokane WA 99210.|Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Harbin, Heilongjiang, China.
authors.forename: Shaman
authors.initials: S
authors.lastname: Luo
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, Washington State University, Spokane WA 99210.
authors.forename: Shannon
authors.initials: S
authors.lastname: Kozlovich
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, Washington State University, Spokane WA 99210.
authors.forename: Philip
authors.initials: P
authors.lastname: Lazarus
mesh_terms: D002273:Carcinogens / Q000032:analysis* / Q000378:metabolism; D005838:Genotype; D005965:Glucuronates / Q000652:urine; D020719:Glucuronides / Q000378:metabolism / Q000652:urine; D014453:Glucuronosyltransferase / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007536:Isomerism; D015778:Minor Histocompatibility Antigens / Q000235:genetics / Q000378:metabolism; D009375:Neoplasms, Glandular and Epithelial; D009602:Nitrosamines / Q000378:metabolism / Q000652:urine*; D011110:Polymorphism, Genetic; D011725:Pyridines / Q000652:urine; D012907:Smoking / Q000652:urine*; D062789:Tobacco Products; D000099148:UGT1A1 Enzyme
chemical_list: D002273:Carcinogens; D005965:Glucuronates; D020719:Glucuronides; D014453:Glucuronosyltransferase; D015778:Minor Histocompatibility Antigens; D009602:Nitrosamines; D011725:Pyridines; D000099148:UGT1A1 Enzyme; C099564:4-((methylnitrosoamino)-1-(3-pyridyl)but-1-yl)beta-omega-glucosiduronic acid; C585057:4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol N-glucuronide; C016583:4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone; C552162:UGT2B10 protein, human; C500513:UGT2B17 protein, human; C099565:4-(methylnitrosamino)-1-(3-pyridyl)-1-butan-1-ol