1
|
Walker VE, Fennell TR, Walker DM, Bauer MJ, Upton PB, Douglas GR, Swenberg JA. Analysis of DNA Adducts and Mutagenic Potency and Specificity in Rats Exposed to Acrylonitrile. Chem Res Toxicol 2020; 33:1609-1622. [PMID: 32529823 DOI: 10.1021/acs.chemrestox.0c00153] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Acrylonitrile (ACN), which is a widely used industrial chemical, induces cancers in multiple organs/tissues of rats by unresolved mechanisms. For this report, evidence for ACN-induced direct/indirect DNA damage and mutagenesis was investigated by assessing the ability of ACN, or its reactive metabolite, 2-cyanoethylene oxide (CEO), to bind to DNA in vitro, to form select DNA adducts [N7-(2'-oxoethyl)guanine, N2,3-ethenoguanine, 1,N6-ethenodeoxyadenosine, and 3,N4-ethenodeoxycytidine] in vitro and/or in vivo, and to perturb the frequency and spectra of mutations in the hypoxanthine-guanine phosphoribosyltransferase (Hprt) gene in rats exposed to ACN in drinking water. Adducts and frequencies and spectra of Hprt mutations were analyzed using published methods. Treatment of DNA from human TK6 lymphoblastoid cells with [2,3-14C]-CEO produced dose-dependent binding of 14C-CEO equivalents, and treatment of DNA from control rat brain/liver with CEO induced dose-related formation of N7-(2'-oxoethyl)guanine. No etheno-DNA adducts were detected in target tissues (brain and forestomach) or nontarget tissues (liver and spleen) in rats exposed to 0, 3, 10, 33, 100, or 300 ppm ACN for up to 105 days or to 0 or 500 ppm ACN for ∼15 months; whereas N7-(2'-oxoethyl)guanine was consistently measured at nonsignificant concentrations near the assay detection limit only in liver of animals exposed to 300 or 500 ppm ACN for ≥2 weeks. Significant dose-related increases in Hprt mutant frequencies occurred in T-lymphocytes from spleens of rats exposed to 33-500 ppm ACN for 4 weeks. Comparisons of "mutagenic potency estimates" for control rats versus rats exposed to 500 ppm ACN for 4 weeks to analogous data from rats/mice treated at a similar age with N-ethyl-N-nitrosourea or 1,3-butadiene suggest that ACN has relatively limited mutagenic effects in rats. Considerable overlap between the sites and types of mutations in ACN-exposed rats and butadiene-exposed rats/mice, but not controls, provides evidence that the carcinogenicity of these epoxide-forming chemicals involves corresponding mutagenic mechanisms.
Collapse
Affiliation(s)
- Vernon E Walker
- Chemical Industry Institute of Toxicology, Research Triangle Park, North Carolina 27709, United States.,Department of Pathology and Laboratory Medicine, University of Vermont, Burlington, Vermont 05405, United States.,The Burlington HC Research Group, Inc., Jericho, Vermont 05465, United States
| | - Timothy R Fennell
- Chemical Industry Institute of Toxicology, Research Triangle Park, North Carolina 27709, United States.,Center for Bioorganic Chemistry, RTI International, Research Triangle Park, North Carolina 27709, United States
| | - Dale M Walker
- The Burlington HC Research Group, Inc., Jericho, Vermont 05465, United States.,Experimental Pathology Laboratories, Sterling, Virginia 20167, United States
| | | | - Patricia B Upton
- Chemical Industry Institute of Toxicology, Research Triangle Park, North Carolina 27709, United States.,Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - George R Douglas
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario K1A 0K9, Canada
| | - James A Swenberg
- Chemical Industry Institute of Toxicology, Research Triangle Park, North Carolina 27709, United States.,Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| |
Collapse
|
2
|
Williams GM, Kobets T, Duan JD, Iatropoulos MJ. Assessment of DNA Binding and Oxidative DNA Damage by Acrylonitrile in Two Rat Target Tissues of Carcinogenicity: Implications for the Mechanism of Action. Chem Res Toxicol 2017; 30:1470-1480. [DOI: 10.1021/acs.chemrestox.7b00105] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Gary M. Williams
- Chemical Safety Program,
Department of Pathology, New York Medical College, Valhalla, New York 10595, United States
| | - Tetyana Kobets
- Chemical Safety Program,
Department of Pathology, New York Medical College, Valhalla, New York 10595, United States
| | - Jian-Dong Duan
- Chemical Safety Program,
Department of Pathology, New York Medical College, Valhalla, New York 10595, United States
| | - Michael J. Iatropoulos
- Chemical Safety Program,
Department of Pathology, New York Medical College, Valhalla, New York 10595, United States
| |
Collapse
|
3
|
Haber LT, Patterson J. Report of an independent peer review of an acrylonitrile risk assessment. Hum Exp Toxicol 2016; 24:487-527. [PMID: 16270753 DOI: 10.1191/0960327105ht552oa] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A peer review panel made up of experts in toxicology, epidemiology, cancer mode of action (MOA), cancer mechanisms, carcinogenicity, genotoxicity, dose–response, US Environmental Protection Agency (EPA) cancer and noncancer methods, pharmacokinetic modeling and acrylonitrile, met on 22–23 September 2003 in Cincinnati, OH. The purpose of the meeting was to provide an independent review of a risk assessment of acrylonitrile that had been prepared by the Acrylonitrile Group (AN Group). Toxicology Excellence for Risk Assessment (TERA) organized the peer review and selected the panel. The panel discussed the toxicity and epidemiology literature of acrylonitrile and MOA information, and reached conclusions regarding its MOA, weight of evidence (WOE) for carcinogenicity, preferred approach for dose-response assessment and risk values. This paper summarizes the discussion and conclusions of the panel regarding the acrylonitrile assessment. Subsequent to the peer review, the authors of the acrylonitrile assessment revised their report and the panel reviewed the revised report. A manuscript of the revised assessment is being published in Regulatory Toxicology and Pharmacology.
Collapse
|
4
|
Meek MEB, Bucher JR, Cohen SM, Dellarco V, Hill RN, Lehman-McKeeman LD, Longfellow DG, Pastoor T, Seed J, Patton DE. A Framework for Human Relevance Analysis of Information on Carcinogenic Modes of Action. Crit Rev Toxicol 2008; 33:591-653. [PMID: 14727733 DOI: 10.1080/713608373] [Citation(s) in RCA: 281] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The human relevance framework (HRF) outlines a four-part process, beginning with data on the mode of action (MOA) in laboratory animals, for evaluating the human relevance of animal tumors. Drawing on U.S. EPA and IPCS proposals for animal MOA analysis, the HRF expands those analyses to include a systematic evaluation of comparability, or lack of comparability, between the postulated animal MOA and related information from human data sources. The HRF evolved through a series of case studies representing several different MOAs. HRF analyses produced divergent outcomes, some leading to complete risk assessment and others discontinuing the process, according to the data available from animal and human sources. Two case examples call for complete risk assessments. One is the default: When data are insufficient to confidently postulate a MOA for test animals, the animal tumor data are presumed to be relevant for risk assessment and a complete risk assessment is necessary. The other is the product of a data-based finding that the animal MOA is relevant to humans. For the specific MOA and endpoint combinations studied for this article, full risk assessments are necessary for potentially relevant MOAs involving cytotoxicity and cell proliferation in animals and humans (Case Study 6, chloroform) and formation of urinary-tract calculi (Case Study 7, melamine). In other circumstances, when data-based findings for the chemical and endpoint combination studied indicate that the tumor-related animal MOA is unlikely to have a human counterpart, there is little reason to continue the risk assessment for that combination. Similarly, when qualitative considerations identify MOAs specific to the test species or quantitative considerations indicate that the animal MOA is unlikely to occur in humans, such hazard findings are generally conclusive and further risk assessment is not necessary for the endpoint-MOA combination under study. Case examples include a tumor-related protein specific to test animals (Case Study 3, d-limonene), the tumor consequences of hormone suppression typical of laboratory animals but not humans (Case Study 4, atrazine), and chemical-related enhanced hormone clearance rates in animals relative to humans (Case Study 5, phenobarbital). The human relevance analysis is highly specific for the chemical-MOA-tissue-endpoint combination under analysis in any particular case: different tissues, different endpoints, or alternative MOAs for a given chemical may result in different human relevance findings. By providing a systematic approach to using MOA data, the HRF offers a new tool for the scientific community's overall effort to enhance the predictive power, reliability and transparency of cancer risk assessment.
Collapse
|
5
|
Esaka Y, Inagaki S, Goto M. Separation procedures capable of revealing DNA adducts. J Chromatogr B Analyt Technol Biomed Life Sci 2003; 797:321-9. [PMID: 14630158 DOI: 10.1016/s1570-0232(03)00607-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Detection and quantification of DNA adducts are very important in relation to diseases such as cancer. Both high sensitivity and high selectivity are required for the detection of DNA adducts because the content of adducts in DNA is very small compared with those of normal bases and only small amounts of DNA samples are available for analysis in general cases. In this paper are described separation procedures such as liquid chromatography, gas chromatography and capillary electrophoresis combined with a detection and identification method such as 32P-postlabeling, mass spectrometry, electrochemical detection, fluorescence detection and immunoassay. The merits and demerits of the procedures are also discussed.
Collapse
Affiliation(s)
- Yukihiro Esaka
- Gifu Pharmaceutical University, 5-6-1 Mitahora-higashi, Gifu 502-8585, Japan.
| | | | | |
Collapse
|
6
|
Léonard A, Gerber GB, Stecca C, Rueff J, Borba H, Farmer PB, Sram RJ, Czeizel AE, Kalina I. Mutagenicity, carcinogenicity, and teratogenicity of acrylonitrile. Mutat Res 1999; 436:263-83. [PMID: 10354525 DOI: 10.1016/s1383-5742(99)00006-x] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Acrylonitrile (AN) is an important intermediary for the synthesis of a variety of organic products, such as artificial fibres, household articles and resins. Although acute effects are the primary concern for an exposure to AN, potential genotoxic, carcinogenic and teratogenic risks of AN have to be taken seriously in view of the large number of workers employed in such industries and the world-wide population using products containing and possibly liberating AN. An understanding of the effect of acrylonitrile must be based on a characterization of its metabolism as well as of the resulting products and their genotoxic properties. Tests for mutagenicity in bacteria have in general been positive, those in plants and on unscheduled DNA synthesis doubtful, and those on chromosome aberrations in vivo negative. Wherever positive results had been obtained, metabolic activation of AN appeared to be a prerequisite. The extent to which such mutagenic effects are significant in man depends, however, also on the conditions of exposure. It appears from the limited data that the ultimate mutagenic factor(s), such as 2-cyanoethylene oxide, may have little opportunity to act under conditions where people are exposed because it is formed only in small amounts and is rapidly degraded. The carcinogenic action of AN has been evaluated by various agencies and ranged from 'reasonably be anticipated to be a human carcinogen' to 'cannot be excluded', the most recent evaluation being 'possibly carcinogenic to humans'. Animal data that confirm the carcinogenic potential of AN have certain limitations with respect to the choice of species, type of tumors and length of follow up. Epidemiological studies which sometimes, but not always, yielded positive results, encounter the usual difficulties of confounding factors in chemical industries. Exposure of workers to AN should continue to be carefully monitored, but AN would not have to be considered a cancer risk to the population provided limitations on releases from consumer products and guidelines on AN in water and air are enforced. AN is teratogenic in laboratory animals (rat, hamster) at high doses when foetal/embryonic (and maternal) toxicity already is manifest. Pregnant workers should not be exposed to AN. In view of the small concentrations generally encountered outside plants, women not professionally exposed would appear not to be at risk of teratogenic effects due to AN. Future research should concentrate on the elucidation of the different degradation pathways in man and on epidemiological studies in workers including pregnant women, assessing also, if possible, individual exposure by bio-monitoring.
Collapse
Affiliation(s)
- A Léonard
- Teratogenicity and Mutagenicity Unit, Catholic University of Louvain, Avenue E. Mounier 72, UCL 7237, B-1200, Brussels, Belgium.
| | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Synthesis of pentafluorophenylthiohydantoin derivatives of adducts formed with dl-valine by acrylonitrile and cyanoethylene oxide. Tetrahedron Lett 1994. [DOI: 10.1016/s0040-4039(00)73094-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|