Correlation between the urine profile of 4-(methylnitrosamino)-1-(3- pyridyl)-1-butanone metabolites and N7-methylguanine in urothelial carcinoma patients
Journal
Cancer Epidemiology Biomarkers and Prevention
Journal Volume
17
Journal Issue
12
Pages
3390-3395
Date Issued
2008
Author(s)
Abstract
A major carcinogen, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), is present in cigarette smoke and its metabolite, 4-(methylnitrosamino)-1-(3- pyridyl)-1-butanol (NNAL), is used as an exposure biomarker for environmental tobacco smoke (ETS). This metabolite (NNAL) can be either detoxified into glucuronidated NNAL (NNAL-Gluc) or activated into an unstable reactive metabolite that methylates DNA along with formation of 4-hydroxy-4-(3-pyridyl)- butyric acid [hydroxy acid (HA)]. Therefore, the carcinogenic risk associated with ETS exposure is greatly modulated by individual variations in metabolic activation and detoxification capabilities. In this study, we defined the urinary HA/total NNAL [HA/total NNAL] ratio as the activation index and NNAL-Gluc/free NNAL [(total NNAL-free NNAL)/free NNAL] ratio as the detoxification index of NNK. The major methylated DNA adduct N 7-methylguanine (N7-MeG), considered as the carcinogenic biomarker for cigarette smoking, was excreted in urine. The objective of this study was to investigate the effects of these metabolic indexes of NNK on N 7-MeG urinary excretion in a population of urothelial carcinoma patients. Urinary levels of total NNAL (free NNAL plus NNAL-Gluc), free NNAL, HA, and N7-MeG were positively correlated with smoking. Furthermore, activation index and detoxification index correlated positively and negatively with N7-MeG levels, respectively. Our results suggest that these metabolic indices may represent the phenotype of individual metabolism capability and modulate the carcinogenic risk of ETS exposure. Copyright ? 2008 American Association for Cancer Research.
SDGs
Other Subjects
4 (methylnitrosamino) 1 (3 pyridyl) 1 butanol; 4 (methylnitrosamino) 1 (3 pyridyl) 1 butanone; 7 methylguanine; glucuronide; adult; aged; article; cancer patient; cancer risk; carcinogenesis; cigarette smoking; controlled study; detoxification; DNA adduct; DNA methylation; female; human; major clinical study; male; metabolism; phenotype; priority journal; urinary excretion; urine level; urogenital tract cancer; Adult; Aged; Aged, 80 and over; Biological Markers; Carcinogens; Female; Guanine; Humans; Male; Middle Aged; Nitrosamines; Pyridines; Questionnaires; Smoking; Urinary Bladder Neoplasms
Type
journal article