1
|
Korenjak M, Temiz NA, Keita S, Chavanel B, Renard C, Sirand C, Cahais V, Mayel T, Vevang KR, Jacobs FC, Guo J, Smith WE, Oram MK, Tăbăran FA, Ahlat O, Cornax I, O'Sullivan MG, Das S, Nandi SP, Cheng Y, Alexandrov LB, Balbo S, Hecht SS, Senkin S, Virard F, Peterson LA, Zavadil J. Human cancer genomes harbor the mutational signature of tobacco-specific nitrosamines NNN and NNK. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.28.600253. [PMID: 38979250 PMCID: PMC11230374 DOI: 10.1101/2024.06.28.600253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Tobacco usage is linked to multiple cancer types and accounts for a quarter of all cancer-related deaths. Tobacco smoke contains various carcinogenic compounds, including polycyclic aromatic hydrocarbons (PAH), though the mutagenic potential of many tobacco-related chemicals remains largely unexplored. In particular, the highly carcinogenic tobacco-specific nitrosamines NNN and NNK form pre-mutagenic pyridyloxobutyl (POB) DNA adducts. In the study presented here, we identified genome-scale POB-induced mutational signatures in cell lines and rat tumors, while also investigating their role in human cancer. These signatures are characterized by T>N and C>T mutations forming from specific POB adducts damaging dT and dC residues. Analysis of 2,780 cancer genomes uncovered POB signatures in ∼180 tumors; from cancer types distinct from the ones linked to smoking-related signatures SBS4 and SBS92. This suggests that, unlike PAH compounds, the POB pathway may contribute uniquely to the mutational landscapes of certain hematological malignancies and cancers of the kidney, breast, prostate and pancreas.
Collapse
|
2
|
Eloranta R, Vilén ST, Keinänen A, Salo T, Qannam A, Bello IO, Snäll J. Oral squamous cell carcinoma: Effect of tobacco and alcohol on cancer location. Tob Induc Dis 2024; 22:TID-22-112. [PMID: 38895166 PMCID: PMC11185050 DOI: 10.18332/tid/189303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 05/12/2024] [Accepted: 05/25/2024] [Indexed: 06/21/2024] Open
Abstract
INTRODUCTION The underlying factors of oral squamous cell cancers (OSCC) have been elucidated, but studies have focused little on etiological differences in affected oral cavity sites. The aim of this retrospective study was to clarify the role of carcinogen exposure in OSCC of different oral cavity areas. METHODS A cross-sectional study of patients with primary OSCC was conducted retrospectively, based on patient records from Helsinki University Hospital, Finland, between January 2016 and December 2020. The patients' self-reported history of tobacco smoking and alcohol use was explained by tumor site, age, sex, tumor size, and lymph node status in a logistic regression model. The information on smoking and alcohol use was compiled from a patient background form. RESULTS In 519 patients, tumors occurred most often in the tongue (51%), gingiva (21%), or floor of the mouth (FOM; 15%). FOM had 26-fold greater odds for a history of smoking and alcohol use than other tumor sites (OR=25.78; 95% CI: 8.02-82.95; p<0.001). Gingival and buccal sites were associated significantly less with smoking and alcohol use (OR=0.43, 95% CI: 0.28-0.67; p<0.001 and OR=0.47; 95% CI: 0.25-0.92; p<0.026, respectively). Patients of older age were less likely to have a history of smoking and alcohol use (AOR=0.95; 95% CI: 0.94-0.97; p<0.001) than younger patients. Tumor size (T3-4) and FOM increased the odds for history of smoking and alcohol use (AOR=1.73; 95% CI: 1.15-2.60; p=0.009 and AOR=26.15; 95% CI: 8.01-84.84; p<0.001, respectively). CONCLUSIONS OSCC of oral cavity sites has notable differences in etiology. FOM seems to be related almost exclusively to conventional smoking and heavy alcohol use.
Collapse
Affiliation(s)
- Riikka Eloranta
- Department of Oral and Maxillofacial Diseases, Clinicum, Faculty of Medicine, University of Helsinki, Helsinki University Hospital, Helsinki, Finland
| | - Suvi-Tuuli Vilén
- Department of Oral and Maxillofacial Diseases, Clinicum, Faculty of Medicine, University of Helsinki, Helsinki University Hospital, Helsinki, Finland
- Department of Oral and Maxillofacial Diseases, Kymenlaakso Central Hospital Kotka, Kotka, Finland
| | - Arvi Keinänen
- Department of Oral and Maxillofacial Diseases, Clinicum, Faculty of Medicine, University of Helsinki, Helsinki University Hospital, Helsinki, Finland
| | - Tuula Salo
- Department of Oral and Maxillofacial Diseases, Clinicum, Faculty of Medicine, University of Helsinki, Helsinki University Hospital, Helsinki, Finland
- Translational Immunology Research Program (TRIMM), University of Helsinki, Helsinki, Finland
- Research Unit of Population Health, Faculty of Medicine, University of Oulu, Oulu, Finland
- Medical Research Center, Oulu University Hospital, University of Oulu, Oulu, Finland
- Department of Pathology, Helsinki University Hospital, University of Helsinki, Helsinki, Finland
| | - Ahmed Qannam
- Department of Oral Medicine and Diagnostic Sciences, King Saud University College of Dentistry, Riyadh, Saudi Arabia
| | - Ibrahim O. Bello
- Department of Oral Medicine and Diagnostic Sciences, King Saud University College of Dentistry, Riyadh, Saudi Arabia
| | - Johanna Snäll
- Department of Oral and Maxillofacial Diseases, Clinicum, Faculty of Medicine, University of Helsinki, Helsinki University Hospital, Helsinki, Finland
| |
Collapse
|
3
|
Stanfill SB, Hecht SS, Joerger AC, González PJ, Maia LB, Rivas MG, Moura JJG, Gupta AK, Le Brun NE, Crack JC, Hainaut P, Sparacino-Watkins C, Tyx RE, Pillai SD, Zaatari GS, Henley SJ, Blount BC, Watson CH, Kaina B, Mehrotra R. From cultivation to cancer: formation of N-nitrosamines and other carcinogens in smokeless tobacco and their mutagenic implications. Crit Rev Toxicol 2023; 53:658-701. [PMID: 38050998 DOI: 10.1080/10408444.2023.2264327] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 09/20/2023] [Indexed: 12/07/2023]
Abstract
Tobacco use is a major cause of preventable morbidity and mortality globally. Tobacco products, including smokeless tobacco (ST), generally contain tobacco-specific N-nitrosamines (TSNAs), such as N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-butanone (NNK), which are potent carcinogens that cause mutations in critical genes in human DNA. This review covers the series of biochemical and chemical transformations, related to TSNAs, leading from tobacco cultivation to cancer initiation. A key aim of this review is to provide a greater understanding of TSNAs: their precursors, the microbial and chemical mechanisms that contribute to their formation in ST, their mutagenicity leading to cancer due to ST use, and potential means of lowering TSNA levels in tobacco products. TSNAs are not present in harvested tobacco but can form due to nitrosating agents reacting with tobacco alkaloids present in tobacco during certain types of curing. TSNAs can also form during or following ST production when certain microorganisms perform nitrate metabolism, with dissimilatory nitrate reductases converting nitrate to nitrite that is then released into tobacco and reacts chemically with tobacco alkaloids. When ST usage occurs, TSNAs are absorbed and metabolized to reactive compounds that form DNA adducts leading to mutations in critical target genes, including the RAS oncogenes and the p53 tumor suppressor gene. DNA repair mechanisms remove most adducts induced by carcinogens, thus preventing many but not all mutations. Lastly, because TSNAs and other agents cause cancer, previously documented strategies for lowering their levels in ST products are discussed, including using tobacco with lower nornicotine levels, pasteurization and other means of eliminating microorganisms, omitting fermentation and fire-curing, refrigerating ST products, and including nitrite scavenging chemicals as ST ingredients.
Collapse
Affiliation(s)
- Stephen B Stanfill
- Tobacco and Volatiles Branch, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Stephen S Hecht
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
| | - Andreas C Joerger
- Structural Genomics Consortium (SGC), Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Pablo J González
- Department of Physics, Universidad Nacional Litoral, and CONICET, Santa Fe, Argentina
| | - Luisa B Maia
- Department of Chemistry, LAQV, REQUIMTE, NOVA School of Science and Technology (FCT NOVA), Caparica, Portugal
| | - Maria G Rivas
- Department of Physics, Universidad Nacional Litoral, and CONICET, Santa Fe, Argentina
| | - José J G Moura
- Department of Chemistry, LAQV, REQUIMTE, NOVA School of Science and Technology (FCT NOVA), Caparica, Portugal
| | | | - Nick E Le Brun
- School of Chemistry, Centre for Molecular and Structural Biochemistry, University of East Anglia, Norwich, UK
| | - Jason C Crack
- School of Chemistry, Centre for Molecular and Structural Biochemistry, University of East Anglia, Norwich, UK
| | - Pierre Hainaut
- Institute for Advanced Biosciences, Grenoble Alpes University, Grenoble, France
| | - Courtney Sparacino-Watkins
- University of Pittsburgh, School of Medicine, Division of Pulmonary Allergy and Critical Care Medicine, Vascular Medicine Institute, PA, USA
| | - Robert E Tyx
- Tobacco and Volatiles Branch, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Suresh D Pillai
- Department of Food Science & Technology, National Center for Electron Beam Research, Texas A&M University, College Station, TX, USA
| | - Ghazi S Zaatari
- Department of Pathology and Laboratory Medicine, American University of Beirut, Beirut, Lebanon
| | - S Jane Henley
- Division of Cancer Prevention and Control, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Benjamin C Blount
- Tobacco and Volatiles Branch, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Clifford H Watson
- Tobacco and Volatiles Branch, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Bernd Kaina
- Institute of Toxicology, University Medical Center, Mainz, Germany
| | - Ravi Mehrotra
- Centre for Health, Innovation and Policy Foundation, Noida, India
| |
Collapse
|
4
|
Termeh-Zonoozi Y, Venugopal PD, Patel V, Gagliano G. Seeing Beyond the Smoke: Selecting Waterpipe Wastewater Chemicals for Risk Assessments. JOURNAL OF HAZARDOUS MATERIALS LETTERS 2023; 4:100074. [PMID: 38357015 PMCID: PMC10866395 DOI: 10.1016/j.hazl.2022.100074] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
Background Increasing use prevalence of waterpipe tobacco smoking raises concerns about environmental impacts from waterpipe waste disposal. The U.S. Food and Drug Administration (FDA) is required to assess the environmental impact of its tobacco regulatory actions per the National Environmental Policy Act. This study builds on FDA's efforts characterizing the aquatic toxicity of waterpipe wastewater chemicals. Methods We compiled a comprehensive list of waterpipe wastewater chemical concentrations from literature. We then selected chemicals for risk assessment by estimating persistence, bioaccumulation, and aquatic toxicity characteristics (PBT; U.S. Environmental Protection Agency), and hazardous concentration values (concentration affecting specific proportion of species). Results Of 38 chemicals in waterpipe wastewater with concentration data, 20 are listed as harmful or potentially harmful constituents (HPHCs) in tobacco smoke and tobacco products by FDA, and 15 are hazardous waste per U. S. Environmental Protection Agency. Among metals, six (cadmium, chromium, lead, mercury, nickel and selenium) are included in both HPHC and hazardous waste lists and were selected for future risk assessments. Among non-metals, nicotine, and 4-methylnitrosamino-1-(3-pyridyl)-1-butanone (NNK) were shortlisted, as they are classified as persistent and toxic. Further, N-nitrosonornicotine (NNN), with a low HC50 value for chronic aquatic toxicity, had high aquatic toxicity concern and is selected. Conclusions The presence of multiple hazardous compounds in waterpipe wastewater highlights the importance of awareness on the proper disposal of waterpipe wastewater in residential and retail settings. Future studies can build on the hazard characterization provided in this study through fate and transport modeling, exposure characterization and risk assessments of waterpipe wastewater chemicals.
Collapse
Affiliation(s)
- Yasmin Termeh-Zonoozi
- Contributed equally
- Center for Tobacco Products, U. S. Food and Drug Administration, 11785 Beltsville Drive, Beltsville, MD 20705
| | - P. Dilip Venugopal
- Contributed equally
- Center for Tobacco Products, U. S. Food and Drug Administration, 11785 Beltsville Drive, Beltsville, MD 20705
| | - Vyomesh Patel
- Center for Tobacco Products, U. S. Food and Drug Administration, 11785 Beltsville Drive, Beltsville, MD 20705
| | - Gregory Gagliano
- Center for Tobacco Products, U. S. Food and Drug Administration, 11785 Beltsville Drive, Beltsville, MD 20705
| |
Collapse
|
5
|
Li Y, Dator RP, Maertens LA, Balbo S, Hecht SS. Mass Spectrometry-Based Metabolic Profiling of Urinary Metabolites of N'-Nitrosonornicotine (NNN) in the Rat. Chem Res Toxicol 2023; 36:769-781. [PMID: 37017527 PMCID: PMC10429506 DOI: 10.1021/acs.chemrestox.3c00025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2023]
Abstract
The tobacco-specific nitrosamine N'-nitrosonornicotine (NNN) and its close analogue 4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NNK) are classified as "carcinogenic to humans" (Group 1) by the International Agency for Research on Cancer. The currently used biomarker to monitor NNN exposure is urinary total NNN (free NNN plus its N-glucuronide). However, total NNN does not provide information about the extent of metabolic activation of NNN as related to its carcinogenicity. Targeted analysis of the major metabolites of NNN in laboratory animals recently led to the identification of N'-nitrosonornicotine-1N-oxide (NNN-N-oxide), a unique metabolite detected in human urine that is specifically formed from NNN. To further investigate NNN urinary metabolites that hold promise as new biomarkers for monitoring NNN exposure, uptake, and/or metabolic activation, we conducted a comprehensive profiling of NNN metabolites in the urine of F344 rats treated with NNN or [pyridine-d4]NNN. Using our optimized high-resolution mass spectrometry (HRMS)-based isotope-labeling method, 46 putative metabolites were identified with robust MS evidence. Out of the 46 candidates, all known major NNN metabolites were identified and structurally confirmed by comparing them to their isotopically labeled standards. More importantly, putative metabolites considered to be exclusively formed from NNN were also identified. The two new representative metabolites─4-(methylthio)-4-(pyridin-3-yl)butanoic acid (23, MPBA) and N-acetyl-S-(5-(pyridin-3-yl)-1H-pyrrol-2-yl)-l-cysteine (24, Py-Pyrrole-Cys-NHAc) ─were identified by comparing them to synthetic standards that were fully characterized by nuclear magnetic resonance and HRMS. They are hypothesized to be formed by NNN α-hydroxylation pathways and thus represent the first potential biomarkers to specifically monitor the uptake plus metabolic activation of NNN in tobacco users.
Collapse
Affiliation(s)
- Yupeng Li
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455
| | - Romel P. Dator
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455
| | - Laura A. Maertens
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455
| | - Silvia Balbo
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455
- Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, Minnesota 55455
| | - Stephen S. Hecht
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455
| |
Collapse
|
6
|
Li Y, Hecht SS. Metabolism and DNA Adduct Formation of Tobacco-Specific N-Nitrosamines. Int J Mol Sci 2022; 23:5109. [PMID: 35563500 PMCID: PMC9104174 DOI: 10.3390/ijms23095109] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 04/29/2022] [Accepted: 04/30/2022] [Indexed: 01/06/2023] Open
Abstract
The tobacco-specific N-nitrosamines 4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NNK) and N'-nitrosonornicotine (NNN) always occur together and exclusively in tobacco products or in environments contaminated by tobacco smoke. They have been classified as "carcinogenic to humans" by the International Agency for Research on Cancer. In 1998, we published a review of the biochemistry, biology and carcinogenicity of tobacco-specific nitrosamines. Over the past 20 years, considerable progress has been made in our understanding of the mechanisms of metabolism and DNA adduct formation by these two important carcinogens, along with progress on their carcinogenicity and mutagenicity. In this review, we aim to provide an update on the carcinogenicity and mechanisms of the metabolism and DNA interactions of NNK and NNN.
Collapse
Affiliation(s)
- Yupeng Li
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA;
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA
| | - Stephen S. Hecht
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA;
| |
Collapse
|
7
|
Hecht SS, Hatsukami DK. Smokeless tobacco and cigarette smoking: chemical mechanisms and cancer prevention. Nat Rev Cancer 2022; 22:143-155. [PMID: 34980891 PMCID: PMC9308447 DOI: 10.1038/s41568-021-00423-4] [Citation(s) in RCA: 66] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/05/2021] [Indexed: 12/19/2022]
Abstract
Tobacco products present a deadly combination of nicotine addiction and carcinogen exposure resulting in millions of cancer deaths per year worldwide. A plethora of smokeless tobacco products lead to unacceptable exposure to multiple carcinogens, including the tobacco-specific nitrosamine N'-nitrosonornicotine, a likely cause of the commonly occurring oral cavity cancers observed particularly in South-East Asian countries. Cigarettes continue to deliver a large number of carcinogens, including tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons and volatile organic compounds. The multiple carcinogens in cigarette smoke are responsible for the complex mutations observed in critical cancer genes. The exposure of smokeless tobacco users and smokers to carcinogens and toxicants can now be monitored by urinary and DNA adduct biomarkers that may be able to identify those individuals at highest risk of cancer so that effective cancer prevention interventions can be initiated. Regulation of the levels of carcinogens, toxicants and nicotine in tobacco products and evidence-based tobacco control efforts are now recognized as established pathways to preventing tobacco related cancer.
Collapse
Affiliation(s)
- Stephen S Hecht
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.
| | | |
Collapse
|
8
|
Sharma M, Shetty SS, Radhakrishnan R. Novel Pathways and Mechanism of Nicotine-Induced Oral Carcinogenesis. Recent Pat Anticancer Drug Discov 2021; 17:66-79. [PMID: 34365933 DOI: 10.2174/1574892816666210806161312] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 05/23/2021] [Accepted: 05/24/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND Smokeless Tobacco (SLT) contains 9 times more nicotine than Smoked Tobacco (SMT). The carcinogenic effect of nicotine is intensified by converting nicotine-to-nicotine-derived Nitrosamines (NDNs). METHODS A review of the literature was conducted with a tailored search strategy to unravel the novel pathways and mechanisms of nicotine-induced oral carcinogenesis. RESULTS Nicotine and NDNs act on nicotinic Acetylcholine Receptors (nAChRs) as agonists. Nicotine facilitates cravings through α4β2nAChR and α7nAChR, via enhanced brain dopamine release. Nicotine binding to nAChR promotes proliferation, migration, invasion, chemoresistance, radioresistance, and metastasis of oral cancer cells. Nicotine binding to α7nAChR on keratinocytes triggers Ras/Raf-1/MEK1/ERK cascade promoting anti-apoptosis and pro-proliferative effects. Furthermore, the nicotine-enhanced metastasis is subdued on nAChR blockade through reduced nuclear localization of p-EGFR. CONCLUSION Protracted exposure to nicotine/NDN augments cancer-stimulatory α7nAChR and desensitizes cancer inhibitory α4β2nAChR. Since nAChRs dictate both addictive and carcinogenic effects of nicotine, it seems counterintuitive to designate nicotine just as an addictive agent devoid of any carcinogenicity.
Collapse
Affiliation(s)
- Mohit Sharma
- Department of Oral Pathology, Sudha Rustagi College of Dental Sciences and Research, Faridabad - 121004. India
| | - Smitha S Shetty
- Department of Oral Pathology, Faculty of Dentistry, Melaka Manipal Medical College, Manipal, (Karnataka). India
| | - Raghu Radhakrishnan
- Department of Oral Pathology, Manipal College of Dental Sciences, Manipal, Manipal Academy of Higher Education, Manipal - 576104. India
| |
Collapse
|
9
|
Li Y, Carlson ES, Zarth AT, Upadhyaya P, Hecht SS. Investigation of 2'-Deoxyadenosine-Derived Adducts Specifically Formed in Rat Liver and Lung DNA by N'-Nitrosonornicotine Metabolism. Chem Res Toxicol 2021; 34:1004-1015. [PMID: 33720703 DOI: 10.1021/acs.chemrestox.1c00012] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The International Agency for Research on Cancer has classified the tobacco-specific nitrosamines N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) as "carcinogenic to humans" (Group 1). To exert its carcinogenicity, NNN requires metabolic activation to form reactive intermediates which alkylate DNA. Previous studies have identified cytochrome P450-catalyzed 2'-hydroxylation and 5'-hydroxylation of NNN as major metabolic pathways, with preferential activation through the 5'-hydroxylation pathway in some cultured human tissues and patas monkeys. So far, the only DNA adducts identified from NNN 5'-hydroxylation in rat tissues are 2-[2-(3-pyridyl)-N-pyrrolidinyl]-2'-deoxyinosine (Py-Py-dI), 6-[2-(3-pyridyl)-N-pyrrolidinyl]-2'-deoxynebularine (Py-Py-dN), and N6-[4-hydroxy-1-(pyridine-3-yl)butyl]-2'-deoxyadenosine (N6-HPB-dAdo) after reduction. To expand the DNA adduct panel formed by NNN 5'-hydroxylation and identify possible activation biomarkers of NNN metabolism, we investigated the formation of dAdo-derived adducts using a new highly sensitive and specific liquid chromatography-nanoelectrospray ionization-high-resolution tandem mass spectrometry method. Two types of NNN-specific dAdo-derived adducts, N6-[5-(3-pyridyl)tetrahydrofuran-2-yl]-2'-deoxyadenosine (N6-Py-THF-dAdo) and 6-[2-(3-pyridyl)-N-pyrrolidinyl-5-hydroxy]-2'-deoxynebularine (Py-Py(OH)-dN), were observed for the first time in calf thymus DNA incubated with 5'-acetoxyNNN. More importantly, Py-Py(OH)-dN was also observed in relatively high abundance in the liver and lung DNA of rats treated with racemic NNN in the drinking water for 3 weeks. These new adducts were characterized using authentic synthesized standards. Both NMR and MS data agreed well with the proposed structures of N6-Py-THF-dAdo and Py-Py(OH)-dN. Reduction of Py-Py(OH)-dN by NaBH3CN led to the formation of Py-Py-dN both in vitro and in vivo, which was confirmed by its isotopically labeled internal standard [pyridine-d4]Py-Py-dN. The NNN-specific dAdo adducts Py-THF-dAdo and Py-Py(OH)-dN formed by NNN 5'-hydroxylation provide a more comprehensive understanding of the mechanism of DNA adduct formation by NNN.
Collapse
Affiliation(s)
- Yupeng Li
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Erik S Carlson
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Adam T Zarth
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Pramod Upadhyaya
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Stephen S Hecht
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, United States
| |
Collapse
|
10
|
Li Y, Hecht SS. Identification of an N'-Nitrosonornicotine-Specific Deoxyadenosine Adduct in Rat Liver and Lung DNA. Chem Res Toxicol 2021; 34:992-1003. [PMID: 33705110 DOI: 10.1021/acs.chemrestox.1c00013] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The tobacco-specific nitrosamines N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) are considered to be two of the most important carcinogens in unburned tobacco and its smoke. They readily cause tumors in laboratory animals and are classified as "carcinogenic to humans" by the International Agency for Research on Cancer. DNA adduct formation by these two carcinogens is believed to play a critical role in tobacco carcinogenesis. Among all the DNA adducts formed by NNN and NNK, 2'-deoxyadenosine (dAdo)-derived adducts have not been fully characterized. In the study reported here, we characterized the formation of N6-[4-(3-pyridyl)-4-oxo-1-butyl]-2'-deoxyadenosine (N6-POB-dAdo) and its reduced form N6-PHB-dAdo formed by NNN 2'-hydroxylation in rat liver and lung DNA. More importantly, we characterized a new dAdo adduct N6-[4-hydroxy-1-(pyridine-3-yl)butyl]-2'-deoxyadenosine (N6-HPB-dAdo) formed after NaBH3CN or NaBH4 reduction both in vitro in calf thymus DNA reacted with 5'-acetoxy-N'-nitrosonornicotine and in vivo in rat liver and lung upon treatment with NNN. This adduct was specifically formed by NNN 5'-hydroxylation. Chemical standards of N6-HPB-dAdo and the corresponding isotopically labeled internal standard [pyridine-d4]N6-HPB-dAdo were synthesized using a four-step method. Both NMR and high-resolution mass spectrometry data agreed well with the proposed structure of N6-HPB-dAdo. The new adduct coeluted with the synthesized internal standard under various LC conditions. Its product ion patterns of MS2 and MS3 transitions were also consistent with the proposed fragmentation patterns. Chromatographic resolution of the two diastereomers of N6-HPB-dAdo was successfully achieved. Quantitation suggested a dose-dependent response of the levels of this new adduct in the liver and lung of rats treated with NNN. However, its level was lower than that of 2-[2-(3-pyridyl)-N-pyrrolidinyl]-2'-deoxyinosine, a previously reported dGuo adduct that is also formed from NNN 5'-hydroxylation. The identification of N6-HPB-dAdo in this study leads to new insights pertinent to the mechanism of carcinogenesis by NNN and to the development of biomarkers of NNN metabolic activation.
Collapse
Affiliation(s)
- Yupeng Li
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Stephen S Hecht
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, United States
| |
Collapse
|
11
|
Guo J, Chen H, Upadhyaya P, Zhao Y, Turesky RJ, Hecht SS. Mass Spectrometric Quantitation of Apurinic/Apyrimidinic Sites in Tissue DNA of Rats Exposed to Tobacco-Specific Nitrosamines and in Lung and Leukocyte DNA of Cigarette Smokers and Nonsmokers. Chem Res Toxicol 2020; 33:2475-2486. [PMID: 32833447 PMCID: PMC7574376 DOI: 10.1021/acs.chemrestox.0c00265] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Metabolic activation of the carcinogenic tobacco-specific nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N'-nitrosonornicotine (NNN) results in formation of reactive electrophiles that modify DNA to produce a variety of products including methyl, 4-(3-pyridyl)-4-oxobutyl (POB)-, and 4-(3-pyridyl)-4-hydroxybutyl adducts. Among these are adducts such as 7-POB-deoxyguanosine (N7POBdG) which can lead to apurinic/apyrimidinic (AP) sites by facile hydrolysis of the base-deoxyribonucleoside bond. In this study, we used a recently developed highly sensitive mass spectrometric method to quantitate AP sites by derivatization with O-(pyridin-3-yl-methyl)hydroxylamine (PMOA) (detection limit, 2 AP sites per 108 nucleotides). AP sites were quantified in DNA isolated from tissues of rats treated with NNN and NNK and from human lung tissue and leukocytes of cigarette smokers and nonsmokers. Rats treated with 5 or 21 mg/kg bw NNK for 4 days by s.c. injection had 2-6 and 2-17 times more AP sites than controls in liver and lung DNA (p < 0.05). Increases in AP sites were also found in liver DNA of rats exposed for 10 and 30 weeks (p < 0.05) but not for 50 and 70 weeks to 5 ppm of NNK in their drinking water. Levels of N7POBG were significantly correlated with AP sites in rats treated with NNK. In rats treated with 14 ppm (S)-NNN in their drinking water for 10 weeks, increased AP site formation compared to controls was observed in oral and nasal respiratory mucosa DNA (p < 0.05). No significant increase in AP sites was found in human lung and leukocyte DNA of cigarette smokers compared to nonsmokers, although AP sites in leukocyte DNA were significantly correlated with urinary levels of the NNK metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL). This is the first study to use mass spectrometry based methods to examine AP site formation by carcinogenic tobacco-specific nitrosamines in laboratory animals and to evaluate AP sites in DNA of smokers and nonsmokers.
Collapse
Affiliation(s)
- Jiehong Guo
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Haoqing Chen
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Pramod Upadhyaya
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Yingchun Zhao
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Robert J. Turesky
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Stephen S. Hecht
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
| |
Collapse
|
12
|
The Multifarious Link between Cytochrome P450s and Cancer. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:3028387. [PMID: 31998435 PMCID: PMC6964729 DOI: 10.1155/2020/3028387] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Revised: 12/08/2019] [Accepted: 12/18/2019] [Indexed: 02/07/2023]
Abstract
Cancer is a leading cause of death worldwide. Cytochrome P450s (P450s) play an important role in the metabolism of endogenous as well as exogenous substances, especially drugs. Moreover, many P450s can serve as targets for disease therapy. Increasing reports of epidemiological, diagnostic, and clinical research indicate that P450s are enzymes that play a major part in the formation of cancer, prevention, and metastasis. The purposes of this review are to shed light on the current state of knowledge about the cancer molecular mechanism involving P450s and to summarize the link between the cancer effects and the participation of P450s.
Collapse
|
13
|
Al-Zoughool M, Bird M, Rice J, Baan RA, Billard M, Birkett N, Krewski D, Zielinski JM. Development of a database on key characteristics of human carcinogens. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2019; 22:264-287. [PMID: 31379270 DOI: 10.1080/10937404.2019.1642593] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A database on mechanistic characteristics of human carcinogenic agents was developed by collecting mechanistic information on agents identified as human carcinogens (Group 1) by the International Agency for Research on Cancer (IARC) in the IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. A two-phase process is described for the construction of the database according to 24 toxicological endpoints, derived from appropriate test systems that were acquired from data obtained from the mechanisms sections of the IARC Monographs (Section 4) and a supplementary PubMed search. These endpoints were then aligned with 10 key characteristics of human carcinogens that reflect the broader attributes of these agents relating to the development of cancer in humans. The considerations involved in linking of toxicological endpoints to key characteristics are described and specific examples of the determination of key characteristics for six specific agents (tamoxifen, hepatitis B virus, arsenic, ultraviolet and solar radiation, tobacco smoking, and dioxin) are provided. Data for humans and animals were tabulated separately, as were results for in-vivo and for in-vitro sources of information. The database was constructed to support a separate analysis of the expression of these endpoints by 86 Group 1 carcinogens, in-vivo and in-vitro along with an analysis of the key characteristics of these agents.
Collapse
Affiliation(s)
- Mustafa Al-Zoughool
- McLaughlin Centre for Population Health Risk Assessment, Faculty of Medicine, University of Ottawa, Ottawa, Canada
- Department of Community and Environmental Health, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Michael Bird
- McLaughlin Centre for Population Health Risk Assessment, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Jerry Rice
- Department of Oncology, Georgetown University Medical Center, Georgetown University, Georgetown, DC, USA
| | - Robert A Baan
- International Agency for Research on Cancer (retired), Lyon, France
| | - Mélissa Billard
- McLaughlin Centre for Population Health Risk Assessment, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Nicholas Birkett
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, Ontario, Canada
| | - Daniel Krewski
- McLaughlin Centre for Population Health Risk Assessment, Faculty of Medicine, University of Ottawa, Ottawa, Canada
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, Ontario, Canada
- Risk Sciences International, Ottawa, Canada
| | - Jan M Zielinski
- McLaughlin Centre for Population Health Risk Assessment, Faculty of Medicine, University of Ottawa, Ottawa, Canada
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, Ontario, Canada
| |
Collapse
|
14
|
Ma B, Stepanov I, Hecht SS. Recent Studies on DNA Adducts Resulting from Human Exposure to Tobacco Smoke. TOXICS 2019; 7:E16. [PMID: 30893918 PMCID: PMC6468371 DOI: 10.3390/toxics7010016] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 03/09/2019] [Accepted: 03/13/2019] [Indexed: 12/22/2022]
Abstract
DNA adducts are believed to play a central role in the induction of cancer in cigarette smokers and are proposed as being potential biomarkers of cancer risk. We have summarized research conducted since 2012 on DNA adduct formation in smokers. A variety of DNA adducts derived from various classes of carcinogens, including aromatic amines, polycyclic aromatic hydrocarbons, tobacco-specific nitrosamines, alkylating agents, aldehydes, volatile carcinogens, as well as oxidative damage have been reported. The results are discussed with particular attention to the analytical methods used in those studies. Mass spectrometry-based methods that have higher selectivity and specificity compared to 32P-postlabeling or immunochemical approaches are preferred. Multiple DNA adducts specific to tobacco constituents have also been characterized for the first time in vitro or detected in vivo since 2012, and descriptions of those adducts are included. We also discuss common issues related to measuring DNA adducts in humans, including the development and validation of analytical methods and prevention of artifact formation.
Collapse
Affiliation(s)
- Bin Ma
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Irina Stepanov
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Stephen S Hecht
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA.
| |
Collapse
|
15
|
Li Y, Ma B, Cao Q, Balbo S, Zhao L, Upadhyaya P, Hecht SS. Mass Spectrometric Quantitation of Pyridyloxobutyl DNA Phosphate Adducts in Rats Chronically Treated with N'-Nitrosonornicotine. Chem Res Toxicol 2019; 32:773-783. [PMID: 30740971 DOI: 10.1021/acs.chemrestox.9b00007] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The tobacco-specific carcinogens N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) require metabolic activation to exert their carcinogenicity. NNN and NNK are metabolized to the same reactive diazonium ions, which alkylate DNA forming pyridyloxobutyl (POB) DNA base and phosphate adducts. We have characterized the formation of both POB DNA base and phosphate adducts in NNK-treated rats and the formation of POB DNA base adducts in NNN-treated rats. However, POB DNA phosphate adducts in NNN-treated rats are still uncharacterized. In this study, we quantified the levels of POB DNA phosphate adducts in tissues of rats chronically treated with ( S)-NNN or ( R)-NNN for 10, 30, 50, and 70 weeks during a carcinogenicity study. The highest amounts of POB DNA phosphate adducts were observed in the esophagus of the ( S)-NNN-treated rats, with a maximum level of 5400 ± 317 fmol/mg DNA at 50 weeks. The abundance of POB DNA phosphate adducts in the esophagus was consistent with the results of the carcinogenicity study showing that the esophagus was the primary site of tumor formation from treatment with ( S)-NNN. Compared to the ( R)-NNN group, the levels of POB DNA phosphate adducts were higher in the oral mucosa, esophagus, and liver, while lower in the nasal mucosa of the ( S)-NNN-treated rats. Among 10 combinations of all isomers of POB DNA phosphate adducts, Ap(POB)C and combinations with thymidine predominated across all the rat tissues examined. In the primary target tissue, esophageal mucosa, Ap(POB)C accounted for ∼20% of total phosphate adducts in the ( S)-NNN treatment group throughout the 70 weeks, with levels ranging from 780 ± 194 to 1010 ± 700 fmol/mg DNA. The results of this study showed that POB DNA phosphate adducts were present in high levels and persisted in target tissues of rats chronically treated with ( S)- or ( R)-NNN. These results improve our understanding of DNA damage during NNN-induced carcinogenesis. The predominant POB DNA phosphate isomers observed, such as Ap(POB)C, may serve as biomarkers for monitoring chronic exposure of tobacco-specific nitrosamines in humans.
Collapse
Affiliation(s)
- Yupeng Li
- Masonic Cancer Center , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| | - Bin Ma
- Masonic Cancer Center , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| | - Qing Cao
- Masonic Cancer Center , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| | - Silvia Balbo
- Masonic Cancer Center , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| | - Lijiao Zhao
- Beijing Key Laboratory of Environmental and Virus Oncology, College of Life Science and Bioengineering , Beijing University of Technology , Beijing 100124 , China
| | - Pramod Upadhyaya
- Masonic Cancer Center , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| | - Stephen S Hecht
- Masonic Cancer Center , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| |
Collapse
|
16
|
Gupta AK, Tulsyan S, Bharadwaj M, Mehrotra R. Grass roots approach to control levels of carcinogenic nitrosamines, NNN and NNK in smokeless tobacco products. Food Chem Toxicol 2019; 124:359-366. [DOI: 10.1016/j.fct.2018.12.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 09/06/2018] [Accepted: 12/08/2018] [Indexed: 12/16/2022]
|
17
|
Fan T, Sun G, Zhao L, Cui X, Zhong R. Metabolic Activation and Carcinogenesis of Tobacco-Specific Nitrosamine N'-Nitrosonornicotine (NNN): A Density Function Theory and Molecular Docking Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:E178. [PMID: 30634532 PMCID: PMC6352179 DOI: 10.3390/ijerph16020178] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 12/20/2018] [Accepted: 01/03/2019] [Indexed: 12/13/2022]
Abstract
N'-nitrosonornicotine (NNN) is one of the tobacco-specific nitrosamines (TSNAs) that exists widely in smoke and smokeless tobacco products. NNN can induce tumors in various laboratory animal models and has been identified by International Agency for Research on Cancer (IARC) as a human carcinogen. Metabolic activation of NNN is primarily initiated by cytochrome P450 enzymes (CYP450s) via 2'-hydroxylation or 5'-hydroxylation. Subsequently, the hydroxylating intermediates undergo spontaneous decomposition to generate diazohydroxides, which can be further converted to alkyldiazonium ions, followed by attacking DNA to form various DNA damages, such as pyridyloxobutyl (POB)-DNA adducts and pyridyl-N-pyrrolidinyl (py-py)-DNA adducts. If not repaired correctly, these lesions would lead to tumor formation. In the present study, we performed density functional theory (DFT) computations and molecular docking studies to understand the mechanism of metabolic activation and carcinogenesis of NNN. DFT calculations were performed to explore the 2'- or 5'- hydroxylation reaction of (R)-NNN and (S)-NNN. The results indicated that NNN catalyzed by the ferric porphyrin (Compound I, Cpd I) at the active center of CYP450 included two steps, hydrogen abstraction and rebound reactions. The free energy barriers of the 2'- and 5'-hydroxylation of NNN are 9.82/8.44 kcal/mol (R/S) and 7.99/9.19 kcal/mol (R/S), respectively, suggesting that the 2'-(S) and 5'-(R) pathways have a slight advantage. The free energy barriers of the decomposition occurred at the 2'-position and 5'-position of NNN are 18.04/18.02 kcal/mol (R/S) and 18.33/19.53 kcal/mol (R/S), respectively. Moreover, we calculated the alkylation reactions occurred at ten DNA base sites induced by the 2'-hydroxylation product of NNN, generating the free energy barriers ranging from 0.86 to 4.72 kcal/mol, which indicated that these reactions occurred easily. The docking study showed that (S)-NNN had better affinity with CYP450s than that of (R)-NNN, which was consistent with the experimental results. Overall, the combined results of the DFT calculations and the docking obtained in this study provide an insight into the understanding of the carcinogenesis of NNN and other TSNAs.
Collapse
Affiliation(s)
- Tengjiao Fan
- Beijing Key Laboratory of Environmental & Viral Oncology, College of Life Science and Bioengineering, Beijing University of Technology, Beijing 100124, China.
| | - Guohui Sun
- Beijing Key Laboratory of Environmental & Viral Oncology, College of Life Science and Bioengineering, Beijing University of Technology, Beijing 100124, China.
| | - Lijiao Zhao
- Beijing Key Laboratory of Environmental & Viral Oncology, College of Life Science and Bioengineering, Beijing University of Technology, Beijing 100124, China.
| | - Xin Cui
- Beijing Key Laboratory of Environmental & Viral Oncology, College of Life Science and Bioengineering, Beijing University of Technology, Beijing 100124, China.
| | - Rugang Zhong
- Beijing Key Laboratory of Environmental & Viral Oncology, College of Life Science and Bioengineering, Beijing University of Technology, Beijing 100124, China.
| |
Collapse
|
18
|
Huang SJ, Xu YM, Lau ATY. Electronic cigarette: A recent update of its toxic effects on humans. J Cell Physiol 2018; 233:4466-4478. [PMID: 29215738 DOI: 10.1002/jcp.26352] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 11/29/2017] [Indexed: 02/05/2023]
Abstract
Electronic cigarettes (e-cigarettes), battery-powered and liquid-vaporizing devices, were invented to replace the conventional cigarette (c-cigarette) smoking for the sake of reducing the adverse effects on multiple organ systems that c-cigarettes have induced. Although some of the identified harmful components in e-cigarettes were alleged to be measured in lower quantity than those in c-cigarettes, researchers unveiled that the toxic effects of e-cigarettes should not be understated. This review is sought for an attempt to throw light on several typical types of e-cigarette components (tobacco-specific nitrosamines, carbonyl compounds, and volatile organic compounds) by revealing their possible impacts on human bodies through different action mechanisms characterized by alteration of specific biomarkers on cellular and molecular levels. In addition, this review is intended to draw the limelight that like c-cigarettes, e-cigarettes could also be accompanied with toxic effects on whole human body, which are especially apparent on respiratory system. From head to foot, from physical aspect to chemical aspect, from genotype to phenotype, potential alterations will take place upon the intake of the liquid aerosol.
Collapse
Affiliation(s)
- Shu-Jie Huang
- Laboratory of Cancer Biology and Epigenetics, Department of Cell Biology and Genetics, Shantou University Medical College, Shantou, Guangdong, People's Republic of China
| | - Yan-Ming Xu
- Laboratory of Cancer Biology and Epigenetics, Department of Cell Biology and Genetics, Shantou University Medical College, Shantou, Guangdong, People's Republic of China
| | - Andy T Y Lau
- Laboratory of Cancer Biology and Epigenetics, Department of Cell Biology and Genetics, Shantou University Medical College, Shantou, Guangdong, People's Republic of China
| |
Collapse
|
19
|
Affiliation(s)
- Yang Yu
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521-0403, United States
| | - Pengcheng Wang
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521-0403, United States
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Yuxiang Cui
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521-0403, United States
| | - Yinsheng Wang
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521-0403, United States
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
| |
Collapse
|
20
|
Lipowicz PJ, Seeman JI. A Model To Estimate the Sources of Tobacco-Specific Nitrosamines in Cigarette Smoke. Chem Res Toxicol 2017; 30:1556-1561. [PMID: 28651431 DOI: 10.1021/acs.chemrestox.7b00046] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Tobacco-specific nitrosamines (TSNAs) are one of the most extensively and continually studied classes of compounds found in tobacco and cigarette smoke.1-5 The TSNAs N-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) have been characterized by the US Food and Drug Administration (FDA) as harmful and potentially harmful constituents in tobacco products,6 and cigarette manufacturers report their levels in cigarette tobacco filler and cigarette smoke to the FDA. NNN and NNK are classified by IARC as carcinogenic to humans.7 TSNAs transfer from tobacco to smoke by evaporation driven by heat and the flow of gases down the cigarette rod. Other TSNA sources in smoke include pyrorelease, where room temperature-unextractable TSNAs are released by smoking, and pyrosynthesis, where TSNAs are formed by reactions during smoking. We propose the first model that quantifies these three sources of TSNA in smoke. In our model, evaporative transfer efficiency of a TSNA is equated to the evaporative transfer efficiency of nicotine. Smoke TSNA measured in excess of what is transferred by evaporation is termed "pyrogeneration," which is the net sum of pyrorelease and pyrosynthesis minus pyrodegredation. This model requires no internal standard, is applicable to commercial cigarettes "as is," and uses existing analytical methods. This model was applied to archived Philip Morris USA data. For commercial blended cigarettes, NNN pyrogeneration appears to be unimportant, but NNK pyrogeneration contributes roughly 30-70% of NNK in smoke with the greater contribution at lower tobacco NNK levels. This means there is an opportunity to significantly reduce smoke NNK by up to 70% if pyrogeneration can be decreased or eliminated, perhaps by finding a way to grow and cure tobacco with reduced matrix-bound NNK. For burley research cigarettes, pyrogeneration may account for 90% or more of both NNN and NNK in smoke.
Collapse
Affiliation(s)
- Peter J Lipowicz
- Research, Development & Regulatory Affairs, Altria Client Services LLC , 601 East Jackson Street, Richmond, Virginia 23219, United States
| | - Jeffrey I Seeman
- SaddlePoint Frontiers , 12001 Bollingbrook Place, Richmond, Virginia 23236, United States
| |
Collapse
|
21
|
Michel AK, Zarth AT, Upadhyaya P, Hecht SS. Identification of 4-(3-Pyridyl)-4-oxobutyl-2'-deoxycytidine Adducts Formed in the Reaction of DNA with 4-(Acetoxymethylnitrosamino)-1-(3-pyridyl)-1-butanone: A Chemically Activated Form of Tobacco-Specific Carcinogens. ACS OMEGA 2017; 2:1180-1190. [PMID: 28393135 PMCID: PMC5377278 DOI: 10.1021/acsomega.7b00072] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 03/14/2017] [Indexed: 06/07/2023]
Abstract
Metabolic activation of the carcinogenic tobacco-specific nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK, 1) and N'-nitrosonornicotine (NNN, 2) results in the formation of 4-(3-pyridyl)-4-oxobutyl (POB)-DNA adducts, several of which have been previously identified both in vitro and in tissues of laboratory animals treated with NNK or NNN. However, 2'-deoxycytidine adducts formed in this process have been incompletely examined in previous studies. Therefore, in this study we prepared characterized standards for the identification of previously unknown 2'-deoxycytidine and 2'-deoxyuridine adducts that could be produced in these reactions. The formation of these products in reactions of 4-(acetoxymethylnitrosamino)-1-(3-pyridyl)-1-butanone (NNKOAc, 3), a model 4-(3-pyridyl)-4-oxobutylating agent, with DNA was investigated. The major 2'-deoxycytidine adduct, identified as its stable cytosine analogue O2-[4-(3-pyridyl)-4-oxobut-1-yl]-cytosine (12), was O2-[4-(3-pyridyl)-4-oxobut-1-yl]-2'-deoxycytidine (13), whereas lesser amounts of 3-[4-(3-pyridyl)-4-oxobut-1-yl]-2'-deoxycytidine (14) and N4-[4-(3-pyridyl)-4-oxobut-1-yl]-2'-deoxycytidine (15) were also observed. The potential conversion of relatively unstable 2'-deoxycytidine adducts to stable 2'-deoxyuridine adducts by treatment of the adducted DNA with bisulfite was also investigated, but the harsh conditions associated with this approach prevented quantitation. The results of this study provide new validated standards for the study of 4-(3-pyridyl)-4-oxobutylation of DNA, a critical reaction in the carcinogenesis by 1 and 2, and demonstrate the presence of previously unidentified 2'-deoxycytidine adducts in this DNA.
Collapse
Affiliation(s)
- Anna K. Michel
- Masonic
Cancer Center, University of Minnesota, 2231 6th Street SE, Room 2-148 CCRB, Minneapolis, Minnesota 55455, United States
| | - Adam T. Zarth
- Masonic
Cancer Center, University of Minnesota, 2231 6th Street SE, Room 2-148 CCRB, Minneapolis, Minnesota 55455, United States
| | - Pramod Upadhyaya
- Masonic
Cancer Center, University of Minnesota, 2231 6th Street SE, Room 2-148 CCRB, Minneapolis, Minnesota 55455, United States
| | - Stephen S. Hecht
- Masonic
Cancer Center, University of Minnesota, 2231 6th Street SE, Room 2-148 CCRB, Minneapolis, Minnesota 55455, United States
| |
Collapse
|
22
|
Yang J, Carmella SG, Hecht SS. Analysis of N'-nitrosonornicotine enantiomers in human urine by chiral stationary phase liquid chromatography-nanoelectrospray ionization-high resolution tandem mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2017; 1044-1045:127-131. [PMID: 28107699 PMCID: PMC5296371 DOI: 10.1016/j.jchromb.2017.01.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 09/06/2016] [Accepted: 01/08/2017] [Indexed: 11/17/2022]
Abstract
We have developed a chiral stationary phase liquid chromatography-nanoelectrospray ionization-high resolution tandem mass spectrometry (LC-NSI-HRMS/MS) method to investigate the enantiomeric composition of low parts per trillion amounts of the carcinogen N'-nitrosonornicotine (NNN) in the urine of cigarette smokers and smokeless tobacco users. (S)-NNN is the major enantiomer in tobacco and is more carcinogenic than (R)-NNN in rats, but no data are available on the enantiomeric composition of NNN in humans. The method used [13C6]NNN as an internal standard and [pyridine-D4]nornicotine to monitor possible artifactual formation of NNN, which was found to be less than 2% of the quantified NNN. The enantiomeric composition of NNN (20.5±27.1fmol/mL urine) in 20 cigarette smokers was 67±5% (S)-NNN while that in 10 smokeless tobacco users (67.1±56.7 fmol/mL urine) was 56±3% (S)-NNN. These results demonstrate that the highly carcinogenic (S)-NNN is the major enantiomer in human urine, and that the enantiomeric composition of NNN in human urine is remarkably similar to that in cigarette smoke and smokeless tobacco. This is the first study to combine chiral stationary phase separations with nanoelectrospray ionization and high resolution tandem mass spectrometry to quantify trace levels of enantiomeric metabolites in human urine.
Collapse
Affiliation(s)
- Jing Yang
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Steven G Carmella
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Stephen S Hecht
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA.
| |
Collapse
|
23
|
Carlson ES, Upadhyaya P, Hecht SS. Evaluation of Nitrosamide Formation in the Cytochrome P450-Mediated Metabolism of Tobacco-Specific Nitrosamines. Chem Res Toxicol 2016; 29:2194-2205. [PMID: 27989137 PMCID: PMC5785922 DOI: 10.1021/acs.chemrestox.6b00384] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
N'-Nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) are carcinogenic tobacco-specific nitrosamines believed to play a vital role in the initiation of tobacco-related cancers. For their carcinogenicities to be exhibited, both NNN and NNK must be metabolically activated by cytochrome P450s, specifically P450 2A6 and P450 2A13, respectively. Prior research has focused on α-hydroxylation, which leads to the formation of several DNA adducts that have been identified and quantified in vivo. However, some studies indicate that P450s can retain substrates within their active sites and perform processive oxidation. For nitrosamines, this would oxidize the highly unstable α-hydroxynitrosamines to potentially more stable nitrosamides, which could also alkylate DNA. Thus, we hypothesized that both NNN and NNK are processively oxidized in vitro to nitrosamides by P450 2A6 and P450 2A13, respectively. To test this hypothesis, we synthesized the NNN- and NNK-derived nitrosamides, determined their half-lives at pH 7.4 and 37 °C, and monitored for nitrosamide formation in an in vitro P450 system with product analysis by LC/NSI+-HRMS/MS. Half-lives of the nitrosamides were determined by HPLC-UV and ranged from 7-35 min, which is more than 40 times longer than the corresponding α-hydroxynitrosamines. Incubation of NNN in the P450 2A6 system resulted in the formation of the nitrosamide N'-nitrosonorcotinine (NNC) at low levels. Similarly, the nitrosamide 4-(methylnitrosamino)-1-(3-pyridyl)-1,4-butanedione (CH2-oxo-NNK) was detected in low amounts in the incubation of NNK with the P450 2A13 system. The other possible NNK-derived nitrosamide, 4-(nitrosoformamido)-1-(3-pyridyl)-1-butanone (CH3-oxo-NNK), was not observed in the P450 2A13 reactions. CH2-oxo-NNK readily formed O6meGua in reactions with dGuo and calf thymus DNA. These results demonstrate that NNC and CH2-oxo-NNK are novel metabolites of NNN and NNK, respectively. Though low-forming, their increased stability may allow for mutagenic DNA damage in vivo. More broadly, this study provides the first account of a cytochrome P450-mediated conversion of nitrosamines to nitrosamides, which warrants further studies to determine how general this phenomenon is in nitrosamine metabolism.
Collapse
Affiliation(s)
- Erik S. Carlson
- Masonic Cancer Center, University of Minnesota, 2231 6 Street SE, 2-210 CCRB, Minneapolis, MN 55455, United States
- Department of Pharmacology, University of Minnesota Medical School, 321 Church Street SE, 6-120 Jackson Hall, Minneapolis, MN 55455
| | - Pramod Upadhyaya
- Masonic Cancer Center, University of Minnesota, 2231 6 Street SE, 2-210 CCRB, Minneapolis, MN 55455, United States
| | - Stephen S. Hecht
- Masonic Cancer Center, University of Minnesota, 2231 6 Street SE, 2-210 CCRB, Minneapolis, MN 55455, United States
| |
Collapse
|