Lung cancer is more prevalent in African Americans as compared to European Americans, and cigarette smoking is the major risk factor in both these groups. Tobacco-specific nitrosamines are among the most significant carcinogens in tobacco products. One ofthe most prevalent of these compounds, 4- (methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), is present in both unburned tobacco and cigarette smoke, and is a remarkably effective lung carcinogen in laboratory animals, inducing lung tumors in rodents independent ofthe route of administration. 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), a metabolite of NNK, is also a pulmonary carcinogen, and its serum levels are related to lung cancer in smokers. Metabolism and DNA adduct formation are critical in cancer induction by NNK. Our goal is to understand whether the observed ethnic/racial differences in lung cancer incidence are due to variations in NNK metabolism. Our overall hypothesis is that cancer susceptibility relates to carcinogen dose and to the balance between carcinogen metabolic activation and detoxification.
Our specific aims are: 1) Conduct a comprehensive analysis of urinary biomarkers of NNK metabolic activation and detoxification in African American and European American smokers. This research builds on our recently developed methodology based on the use of deuterium-labeled NNK. 2) Measure in exfoliated oral mucosa cells of African American and European American smokers DNA adducts formed as a result of NNK metabolic activation. This is critical to an understanding of the balance between the urinary excretion of NNK metabolites and the extent of NNK DNA binding. In the future, this balance could serve as a direct indicator of cancer susceptibility in humans. 3) Investigate the relationship between levels of NNK-derived DNA adducts measured in oral mucosa cells and the rates of repair of these adducts in cultured lymphocytes from our subjects. This research will complement the results obtained in Specific Aims 1 and 2. In summary, the results of these experiments will provide exciting new data on differences in NNK metabolic activation and detoxification, as well as formation of NNK-derived DNA adducts and related DNA repair capacity in African Americans and European Americans. This will also help to test the overall hypothesis that differences in the mechanisms of NNK carcinogenesis are related to lung cancer susceptibility in humans.

Public Health Relevance

Smoking-related lung cancer is the leading cause of cancer death in the United States and worldwide, and is more prevalent in African Americans as compared to European Americans. The proposed study is to examine whether the observed ethnic/racial differences in lung cancer incidence are due to variations in metabolism of a tobacco-specific lung carcinogen. Findings of this study will contribute to the development of preventive measures against lung cancer development in smokers

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Program Projects (P01)
Project #
5P01CA138338-04
Application #
8473185
Study Section
Special Emphasis Panel (ZCA1-RPRB-7)
Project Start
Project End
Budget Start
2013-04-01
Budget End
2014-03-31
Support Year
4
Fiscal Year
2013
Total Cost
$176,304
Indirect Cost
$23,652
Name
University of Minnesota Twin Cities
Department
Type
DUNS #
555917996
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
Murphy, Sharon E; von Weymarn, Linda B; Parenteau, Marc et al. (2018) Influence of UGT2B10 Genotype on Urinary Excretion of 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanol- N-glucuronide by African American Smokers. Chem Res Toxicol 31:168-175
Degner, Amanda; Carlsson, Henrik; Karlsson, Isabella et al. (2018) Discovery of Novel N-(4-Hydroxybenzyl)valine Hemoglobin Adducts in Human Blood. Chem Res Toxicol :
Park, Sungshim L; Patel, Yesha M; Loo, Lenora W M et al. (2018) Association of internal smoking dose with blood DNA methylation in three racial/ethnic populations. Clin Epigenetics 10:110
Murphy, Sharon E; Park, Sungshim Lani; Balbo, Silvia et al. (2018) Tobacco biomarkers and genetic/epigenetic analysis to investigate ethnic/racial differences in lung cancer risk among smokers. NPJ Precis Oncol 2:17
Hecht, Stephen S (2017) Oral Cell DNA Adducts as Potential Biomarkers for Lung Cancer Susceptibility in Cigarette Smokers. Chem Res Toxicol 30:367-375
Chai, Weiwen; Morimoto, Yukiko; Cooney, Robert V et al. (2017) Dietary Red and Processed Meat Intake and Markers of Adiposity and Inflammation: The Multiethnic Cohort Study. J Am Coll Nutr 36:378-385
Park, Sungshim L; Murphy, Sharon E; Wilkens, Lynne R et al. (2017) Association of CYP2A6 activity with lung cancer incidence in smokers: The multiethnic cohort study. PLoS One 12:e0178435
Murphy, Sharon E (2017) Nicotine Metabolism and Smoking: Ethnic Differences in the Role of P450 2A6. Chem Res Toxicol 30:410-419
Boldry, Emily J; Patel, Yesha M; Kotapati, Srikanth et al. (2017) Genetic Determinants of 1,3-Butadiene Metabolism and Detoxification in Three Populations of Smokers with Different Risks of Lung Cancer. Cancer Epidemiol Biomarkers Prev 26:1034-1042
Sangaraju, Dewakar; Boldry, Emily J; Patel, Yesha M et al. (2017) Isotope Dilution nanoLC/ESI+-HRMS3 Quantitation of Urinary N7-(1-Hydroxy-3-buten-2-yl) Guanine Adducts in Humans and Their Use as Biomarkers of Exposure to 1,3-Butadiene. Chem Res Toxicol 30:678-688

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