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Schrenk D, Bignami M, Bodin L, Chipman JK, del Mazo J, Hogstrand C, (Ron) Hoogenboom L, Leblanc J, Nebbia CS, Nielsen E, Ntzani E, Petersen A, Sand S, Schwerdtle T, Vleminckx C, Wallace H, Romualdo B, Cristina F, Stephen H, Marco I, Mosbach‐Schulz O, Riolo F, Christodoulidou A, Grasl‐Kraupp B. Risk assessment of N-nitrosamines in food. EFSA J 2023; 21:e07884. [PMID: 36999063 PMCID: PMC10043641 DOI: 10.2903/j.efsa.2023.7884] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023] Open
Abstract
EFSA was asked for a scientific opinion on the risks to public health related to the presence of N-nitrosamines (N-NAs) in food. The risk assessment was confined to those 10 carcinogenic N-NAs occurring in food (TCNAs), i.e. NDMA, NMEA, NDEA, NDPA, NDBA, NMA, NSAR, NMOR, NPIP and NPYR. N-NAs are genotoxic and induce liver tumours in rodents. The in vivo data available to derive potency factors are limited, and therefore, equal potency of TCNAs was assumed. The lower confidence limit of the benchmark dose at 10% (BMDL10) was 10 μg/kg body weight (bw) per day, derived from the incidence of rat liver tumours (benign and malignant) induced by NDEA and used in a margin of exposure (MOE) approach. Analytical results on the occurrence of N-NAs were extracted from the EFSA occurrence database (n = 2,817) and the literature (n = 4,003). Occurrence data were available for five food categories across TCNAs. Dietary exposure was assessed for two scenarios, excluding (scenario 1) and including (scenario 2) cooked unprocessed meat and fish. TCNAs exposure ranged from 0 to 208.9 ng/kg bw per day across surveys, age groups and scenarios. 'Meat and meat products' is the main food category contributing to TCNA exposure. MOEs ranged from 3,337 to 48 at the P95 exposure excluding some infant surveys with P95 exposure equal to zero. Two major uncertainties were (i) the high number of left censored data and (ii) the lack of data on important food categories. The CONTAM Panel concluded that the MOE for TCNAs at the P95 exposure is highly likely (98-100% certain) to be less than 10,000 for all age groups, which raises a health concern.
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Hu SC, Min S, Kang HK, Yang DJ, Basavarajappa M, Lewis SM, Davis KJ, Patton RE, Bryant MS, Sepehr E, Trbojevich R, Pearce MG, Bishop ME, Ding W, Heflich RH, Maisha MP, Felton R, Chemerynski S, Yee SB, Coraggio M, Rosenfeldt H, Yeager RP, Howard PC, Tang Y. 90-day nose-only inhalation toxicity study of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in Sprague-Dawley rats. Food Chem Toxicol 2022; 160:112780. [PMID: 34965465 DOI: 10.1016/j.fct.2021.112780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 12/17/2021] [Accepted: 12/22/2021] [Indexed: 11/29/2022]
Abstract
4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is one of the key tobacco-specific nitrosamines that plays an important role in human lung carcinogenesis. Repeated dose inhalation toxicity data on NNK, particularly relevant to cigarette smoking, however, is surprisingly limited. Hence, there is a lack of direct information available on the carcinogenic and potential non-carcinogenic effects of NNK via inhalational route exposure. In the present study, the subchronic inhalation toxicity of NNK was evaluated in Sprague Dawley rats. Both sexes (9-10 weeks age; 23 rats/sex/group) were exposed by nose-only inhalation to air, vehicle control (75% propylene glycol), or 0.2, 0.8, 3.2, or 7.8 mg/kg body weight (BW)/day of NNK (NNK aerosol concentrations: 0, 0, 0.0066, 0.026, 0.11, or 0.26 mg/L air) for 1 h/day for 90 consecutive days. Toxicity was evaluated by assessing body weights; food consumption; clinical pathology; histopathology; organ weights; blood, urine, and tissue levels of NNK, its major metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), and their glucuronides (reported as total NNK, tNNK, and total NNAL, tNNAL, respectively); tissue levels of the DNA adduct O6-methylguanine; blood and bone marrow micronucleus (MN) frequency; and bone marrow DNA strand breaks (comet assay). The results showed that NNK exposure caused multiple significant adverse effects, with the most sensitive endpoint being non-neoplastic lesions in the nose. Although the genotoxic biomarker O6-methylguanine was detected, genotoxicity from NNK exposure was negative in the MN and comet assays. The Lowest-Observed-Adverse-Effect-Level (LOAEL) was 0.8 mg/kg BW/day or 0.026 mg/L air of NNK for 1 h/day for both sexes. The No-Observed-Adverse-Effect-Level (NOAEL) was 0.2 mg/kg BW/day or 0.0066 mg/L air of NNK for 1 h/day for both sexes. The results of this study provide new information relevant to assessing the human exposure hazard of NNK.
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Affiliation(s)
- Shu-Chieh Hu
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR, 72079, USA
| | - Seonggi Min
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR, 72079, USA
| | - Hyun-Ki Kang
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR, 72079, USA
| | - Dong-Jin Yang
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR, 72079, USA
| | - Mallikarjuna Basavarajappa
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR, 72079, USA
| | - Sherry M Lewis
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR, 72079, USA
| | - Kelly J Davis
- Toxicologic Pathology Associates, National Center for Toxicological Research, Jefferson, AR, 72079, USA
| | - Ralph E Patton
- Toxicologic Pathology Associates, National Center for Toxicological Research, Jefferson, AR, 72079, USA
| | - Matthew S Bryant
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR, 72079, USA
| | - Estatira Sepehr
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR, 72079, USA
| | - Raul Trbojevich
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR, 72079, USA
| | - Mason G Pearce
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR, 72079, USA
| | - Michelle E Bishop
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR, 72079, USA
| | - Wei Ding
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR, 72079, USA
| | - Robert H Heflich
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR, 72079, USA
| | - MacKean P Maisha
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR, 72079, USA
| | - Robert Felton
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR, 72079, USA
| | - Susan Chemerynski
- The Center for Tobacco Products (CTP), U.S. Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Steven B Yee
- The Center for Tobacco Products (CTP), U.S. Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Melis Coraggio
- The Center for Tobacco Products (CTP), U.S. Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Hans Rosenfeldt
- The Center for Tobacco Products (CTP), U.S. Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - R Philip Yeager
- The Center for Tobacco Products (CTP), U.S. Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Paul C Howard
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR, 72079, USA
| | - Yunan Tang
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR, 72079, USA.
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Hu SC, Min S, Kang HK, Yang DJ, Lewis SM, Davis KJ, Patton RE, Bryant MS, Sepehr E, Trbojevich R, Pearce MG, Bishop ME, Heflich RH, Maisha MP, Felton R, Chemerynski S, Yee SB, Coraggio M, Rosenfeldt H, Yeager RP, Howard PC, Tang Y. 14-Day Nose-Only Inhalation Toxicity and Haber's Rule Study of NNK in Sprague-Dawley Rats. Toxicol Sci 2021; 183:319-337. [PMID: 34329464 DOI: 10.1093/toxsci/kfab094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is one of the key tobacco-specific nitrosamines that plays an important role in human lung carcinogenesis. However, repeated inhalation toxicity data on NNK, which is more directly relevant to cigarette smoking, are currently limited. In the present study, the subacute inhalation toxicity of NNK was evaluated in Sprague Dawley rats. Both sexes (9-10 weeks age; 16 rats/sex/group) were exposed by nose-only inhalation to air, vehicle control (75% propylene glycol), or 0.8, 3.2, 12.5, or 50 mg/kg body weight (BW)/day of NNK (NNK aerosol concentrations: 0, 0, 0.03, 0.11, 0.41, or 1.65 mg/L air) for 1 hour/day for 14 consecutive days. Toxicity was evaluated by assessing body and organ weights; food consumption; clinical pathology; histopathology observations; blood, urine, and tissue levels of NNK, its major metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), and their glucuronides (reported as total NNK, tNNK, and total NNAL, tNNAL, respectively); O6-methylguanine DNA adduct formation; and blood and bone marrow micronucleus frequency. Whether the subacute inhalation toxicity of NNK followed Haber's Rule was also determined using additional animals exposed 4 hours/day. The results showed that NNK exposure caused multiple significant adverse effects, with the most sensitive endpoint being non-neoplastic histopathological lesions in the nose. The lowest-observed-adverse-effect level (LOAEL) was 0.8 mg/kg BW/day or 0.03 mg/L air for 1 hour/day for both sexes. An assessment of Haber's Rule indicated that 14-day inhalation exposure to the same dose at a lower concentration of NNK aerosol for a longer time (4 hours daily) resulted in greater adverse effects than exposure to a higher concentration of NNK aerosol for a shorter time (1 hour daily).
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Affiliation(s)
- Shu-Chieh Hu
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Seonggi Min
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Hyun-Ki Kang
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Dong-Jin Yang
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Sherry M Lewis
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Kelly J Davis
- Toxicologic Pathology Associates, National Center for Toxicological Research, Jefferson, AR
| | - Ralph E Patton
- Toxicologic Pathology Associates, National Center for Toxicological Research, Jefferson, AR
| | - Matthew S Bryant
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Estatira Sepehr
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Raul Trbojevich
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Mason G Pearce
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Michelle E Bishop
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Robert H Heflich
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - MacKean P Maisha
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Robert Felton
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Susan Chemerynski
- The Center for Tobacco Products (CTP), U.S. Food and Drug Administration, Silver Spring, MD
| | - Steven B Yee
- The Center for Tobacco Products (CTP), U.S. Food and Drug Administration, Silver Spring, MD
| | - Melis Coraggio
- The Center for Tobacco Products (CTP), U.S. Food and Drug Administration, Silver Spring, MD
| | - Hans Rosenfeldt
- The Center for Tobacco Products (CTP), U.S. Food and Drug Administration, Silver Spring, MD
| | - R Philip Yeager
- The Center for Tobacco Products (CTP), U.S. Food and Drug Administration, Silver Spring, MD
| | - Paul C Howard
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Yunan Tang
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
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4
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Evaluation of a 28-day repeated-dose micronucleus test in rat glandular stomach, colon, and liver using gastrointestinal tract-targeted genotoxic-carcinogens and non-carcinogens. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2019; 844:62-68. [DOI: 10.1016/j.mrgentox.2019.05.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 05/17/2019] [Accepted: 05/17/2019] [Indexed: 11/19/2022]
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5
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Kirkland D, Uno Y, Luijten M, Beevers C, van Benthem J, Burlinson B, Dertinger S, Douglas GR, Hamada S, Horibata K, Lovell DP, Manjanatha M, Martus HJ, Mei N, Morita T, Ohyama W, Williams A. In vivo genotoxicity testing strategies: Report from the 7th International workshop on genotoxicity testing (IWGT). MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2019; 847:403035. [PMID: 31699340 DOI: 10.1016/j.mrgentox.2019.03.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 03/13/2019] [Accepted: 03/23/2019] [Indexed: 12/14/2022]
Abstract
The working group reached complete or majority agreement on many issues. Results from TGR and in vivo comet assays for 91 chemicals showed they have similar ability to detect in vivo genotoxicity per se with bacterial mutagens and Ames-positive carcinogens. TGR and comet assay results were not significantly different when compared with IARC Group 1, 2 A, and unclassified carcinogens. There were significantly more comet assay positive responses for Group 2B chemicals, and for IARC classified and unclassified carcinogens combined, which may be expected since mutation is a sub-set of genotoxicity. A liver comet assay combined with the bone marrow/blood micronucleus (MNviv) test would detect in vivo genotoxins that do not exhibit tissue-specific or site-of-contact effects, and is appropriate for routine in vivo genotoxicity testing. Generally for orally administered substances, a comet assay at only one site-of-contact GI tract tissue (stomach or duodenum/jejunum) is required. In MNviv tests, evidence of target tissue exposure can be obtained in a number of different ways, as recommended by ICH S2(R1) and EFSA (Hardy et al., 2017). Except for special cases the i.p. route is inappropriate for in vivo testing; for risk evaluations more weight should be given to data from a physiologically relevant administration route. The liver MN test is sufficiently validated for the development of an OECD guideline. However, the impact of dosing animals >6 weeks of age needs to be evaluated. The GI tract MN test shows promise but needs more validation for an OECD guideline. The Pig-a assay detects systemically available mutagens and is a valuable follow-up to in vitro positive results. A new freeze-thaw protocol provides more flexibility. Mutant reticulocyte and erythrocyte frequencies should both be determined. Preliminary data are available for the Pig-a assay in male rat germ cells which require validation including germ cell DNA mutation origin.
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Affiliation(s)
- David Kirkland
- Kirkland Consulting, PO Box 79, Tadcaster, LS24 0AS, United Kingdom.
| | - Yoshifumi Uno
- Mitsubishi Tanabe Pharma Corporation, 2-2-50, Kawagishi, Toda, Saitama, 335-8505, Japan
| | - Mirjam Luijten
- National Institute for Public Health and the Environment (RIVM), Centre for Health Protection, Bilthoven, the Netherlands
| | - Carol Beevers
- Exponent International Ltd., The Lenz, Hornbeam Park, Harrogate, HG2 8RE, United Kingdom
| | - Jan van Benthem
- National Institute for Public Health and the Environment (RIVM), Centre for Health Protection, Bilthoven, the Netherlands
| | - Brian Burlinson
- Envigo, Huntingdon, Cambridgeshire, PE28 4HS, United Kingdom
| | | | - George R Douglas
- Environmental Health Science Research Bureau, Health Canada, Ottawa, K1A 0K9, Canada
| | - Shuichi Hamada
- LSI Medience Corporation, 14-1 Sunayama, Kamisu-shi, Ibaraki, 314-0255, Japan
| | - Katsuyoshi Horibata
- National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki, Kanagawa, 210-9501, Japan
| | - David P Lovell
- St George's Medical School, University of London, London, SW17 0RE, United Kingdom
| | | | | | - Nan Mei
- US FDA, National Center for Toxicological Research, Jefferson, AR, USA
| | - Takeshi Morita
- National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki, Kanagawa, 210-9501, Japan
| | - Wakako Ohyama
- Yakult Honsha Co., Ltd., 5-11, Izumi, Kunitachi-shi, Tokyo, 186-8650, Japan
| | - Andrew Williams
- Environmental Health Science Research Bureau, Health Canada, Ottawa, K1A 0K9, Canada
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Guo X, Ni J, Liang Z, Xue J, Fenech MF, Wang X. The molecular origins and pathophysiological consequences of micronuclei: New insights into an age-old problem. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2018; 779:1-35. [PMID: 31097147 DOI: 10.1016/j.mrrev.2018.11.001] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 11/07/2018] [Accepted: 11/08/2018] [Indexed: 02/07/2023]
Abstract
Micronuclei (MN), the small nucleus-like bodies separated from the primary nucleus, can exist in cells with numerical and/or structural chromosomal aberrations in apparently normal tissues and more so in tumors in humans. While MN have been observed for over 100 years, they were merely and constantly considered as passive indicators of chromosome instability (CIN) for a long time. Relatively little is known about the molecular origins and biological consequences of MN. Rapid technological advances are helping to close these gaps. Very recent studies provide exciting evidence that MN act as key platform for chromothripsis and a trigger of innate immune response, suggesting that MN could affect cellular functions by both genetic and nongenetic means. These previously unappreciated findings have reawakened widespread interests in MN. In this review, the diverse mechanisms leading to MN generation and the complex fate profiles of MN are discussed, together with the evidence for their contribution to CIN, inflammation, senescence and cell death. Moreover, we put this knowledge together into a speculative perspective on how MN may be responsible for cancer development and how their presence may influence the choice of treatment. We suggest that the heterogeneous responses to MN may function physiological to ensure the arrestment, elimination and immune clearance of damaged cells, but pathologically, may enable the survival and oncogenic transformation of cells bearing CIN. These insights not only underscore the complexity of MN biology, but also raise a host of new questions and provide fertile ground for future research.
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Affiliation(s)
- Xihan Guo
- School of Life Sciences, The Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Yunnan Normal University, Kunming, Yunnan, 650500, China
| | - Juan Ni
- School of Life Sciences, The Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Yunnan Normal University, Kunming, Yunnan, 650500, China
| | - Ziqing Liang
- School of Life Sciences, The Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Yunnan Normal University, Kunming, Yunnan, 650500, China
| | - Jinglun Xue
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200433, China
| | - Michael F Fenech
- University of South Australia, Adelaide, SA, 5000, Australia; Genome Health Foundation, North Brighton, SA, 5048, Australia.
| | - Xu Wang
- School of Life Sciences, The Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Yunnan Normal University, Kunming, Yunnan, 650500, China.
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Nagasue R, Murata I, Sasaki K, Sakai R, Miyajima H, Shimoda M. Effectiveness of the liver micronucleus assay using juvenile mice. J Vet Med Sci 2017; 79:1310-1317. [PMID: 28603212 PMCID: PMC5559381 DOI: 10.1292/jvms.17-0116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study investigated the effectiveness of the liver micronucleus (MN) assay using juvenile mice. Therefore, we analyzed various hepatic cytochrome P450 (CYP)- mediated activities of ethoxyresorufin
O-deethylation, pentoxyresorufin O-dealkylation, tolbutamide hydroxylation, bufuralol 1’-hydroxylation, aniline hydroxylation and midazolam 4-hydroxylation by CYP1A, CYP2B, CYP2C, CYP2D, CYP2E and
CYP3A, respectively, in non-treated male ICR mice aged between 3 and 8 weeks. The enzyme efficiency levels in 3- and 4-week-old mice were approximately similar to or higher than those in 8-week-old mice, except for CYP1A and CYP2E
in 3- and 4-week-old mice, respectively. Since these results suggest that juvenile mice have sufficient activities for most CYP enzymes, we also conducted a liver MN assay using diethylnitrosamine (DEN), a rodent hepatocarcinogen,
on male ICR mice aged between 3 and 6 weeks. A peripheral blood (PB) MN assay was performed simultaneously in 4-week-old mice. Assays incorporating DEN produced positive results in 3- and 4-week-old mice and showed a
dose-dependent increase in the micronucleated hepatocyte frequencies at 4 weeks. Both the liver MN assay in 5- and 6-week-old mice and the PB MN assay had negative results when using DEN. These results suggest that 3- and
4-week-old mice have micronuclei-inducing potential in the liver to detect genotoxic compounds using the liver MN assay.
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Affiliation(s)
- Ritsuko Nagasue
- Laboratory of Veterinary Pharmacology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.,Research Laboratory for Development, Shionogi & Co., Ltd., 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825, Japan
| | - Ikue Murata
- Laboratory of Veterinary Pharmacology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
| | - Kazuaki Sasaki
- Laboratory of Veterinary Pharmacology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
| | - Rina Sakai
- Research Laboratory for Development, Shionogi & Co., Ltd., 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825, Japan
| | - Hirofumi Miyajima
- Research Laboratory for Development, Shionogi & Co., Ltd., 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825, Japan
| | - Minoru Shimoda
- Laboratory of Veterinary Pharmacology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
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Hintzsche H, Hemmann U, Poth A, Utesch D, Lott J, Stopper H. Fate of micronuclei and micronucleated cells. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2017; 771:85-98. [PMID: 28342454 DOI: 10.1016/j.mrrev.2017.02.002] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Indexed: 01/24/2023]
Abstract
The present review describes available evidence about the fate of micronuclei and micronucleated cells. Micronuclei are small, extranuclear chromatin bodies surrounded by a nuclear envelope. The mechanisms underlying the formation of micronuclei are well understood but not much is known about the potential fate of micronuclei and micronucleated cells. Many studies with different experimental approaches addressed the various aspects of the post-mitotic fate of micronuclei and micronucleated cells. These studies are reviewed here considering four basic possibilities for potential fates of micronuclei: degradation of the micronucleus or the micronucleated cell, reincorporation into the main nucleus, extrusion from the cell, and persistence in the cytoplasm. Two additional fates need to be considered: premature chromosome condensation/chromothripsis and the elimination of micronucleated cells by apoptosis, yielding six potential fates for micronuclei and/or micronucleated cells. The available data is still limited, but it can be concluded that degradation and extrusion of micronuclei might occur in rare cases under specific conditions, reincorporation during the next mitosis occurs more frequently, and the majority of the micronuclei persist without alteration at least until the next mitosis, possibly much longer. Overall, the consequences of micronucleus formation on the cellular level are still far from clear, but they should be investigated further because micronucleus formation may contribute to the initial and later steps of malignant cell transformation, by causing gain or loss of genetic material in the daughter cells and by the possibility of massive chromosome rearrangement in chromosomes entrapped within a micronucleus by the mechanisms of chromothripsis and chromoanagenesis.
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Affiliation(s)
- Henning Hintzsche
- Institut für Pharmakologie und Toxikologie, Universität Würzburg, Germany; Bavarian Health and Food Safety Authority, Erlangen, Germany.
| | - Ulrike Hemmann
- Sanofi-Aventis Deutschland GmbH, Frankfurt am Main, Germany
| | | | | | - Jasmin Lott
- Boehringer Ingelheim Pharma GmbH & Co KG, Biberach, Germany
| | - Helga Stopper
- Institut für Pharmakologie und Toxikologie, Universität Würzburg, Germany
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Shimada K, Yamamoto M, Takashima M, Seki J, Miyamae Y, Wakata A. Prolonged rest period enables the detection of micronucleated hepatocytes in the liver of young adult rats after a single dose of diethylnitrosamine or mitomycin C. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2015; 791:38-41. [DOI: 10.1016/j.mrgentox.2015.07.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 07/22/2015] [Accepted: 07/23/2015] [Indexed: 10/23/2022]
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Takashima R, Takasawa H, Kawasako K, Ohyama W, Okada E, Narumi K, Fujiishi Y, Wako Y, Yasunaga K, Hattori A, Kawabata M, Nakadate K, Nakagawa M, Hamada S. Evaluation of a repeated dose liver micronucleus assay in rats treated with two genotoxic hepatocarcinogens, dimethylnitrosamine and 2-acetylaminofluorene: The possibility of integrating micronucleus tests with multiple tissues into a repeated dose general toxicity study. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2015; 780-781:18-24. [DOI: 10.1016/j.mrgentox.2014.10.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 10/17/2014] [Indexed: 11/26/2022]
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Evaluation of the repeated-dose liver and gastrointestinal tract micronucleus assays with 22 chemicals using young adult rats: Summary of the collaborative study by the Collaborative Study Group for the Micronucleus Test (CSGMT)/The Japanese Environmental Mutagen Society (JEMS) – Mammalian Mutagenicity Study Group (MMS). MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2015; 780-781:2-17. [DOI: 10.1016/j.mrgentox.2015.01.001] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 01/02/2015] [Indexed: 11/21/2022]
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Micronucleus induction in rat liver and bone marrow by acute vs. repeat doses of the genotoxic hepatocarcinogen monocrotaline. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2015; 780-781:64-70. [DOI: 10.1016/j.mrgentox.2014.12.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Accepted: 12/28/2014] [Indexed: 11/21/2022]
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Imamura T, Koeda A, Morimoto K, Hatakeyama H, Suzuki H, Wako Y, Kawasako K, Otabe K, Sato SI. Evaluation of a repeated-dose liver micronucleus assay with 2,6-dinitrotoluene using young adult rats. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2015; 780-781:46-50. [DOI: 10.1016/j.mrgentox.2014.11.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 11/11/2014] [Indexed: 12/01/2022]
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Uno Y, Morita T, Luijten M, Beevers C, Hamada S, Itoh S, Ohyama W, Takasawa H. Recommended protocols for the liver micronucleus test: Report of the IWGT working group. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2014; 783:13-8. [PMID: 25953396 DOI: 10.1016/j.mrgentox.2014.10.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 10/27/2014] [Indexed: 01/06/2023]
Abstract
At the 6th International Workshop on Genotoxicity Testing (IWGT), the liver micronucleus test working group discussed practical aspects of the in vivo rodent liver micronucleus test (LMNT). The group members focused on the three methodologies currently used, i.e., a partial hepatectomy (PH) method, a juvenile/young rat (JR) method, and a repeated-dose (RD) method in adult rodents. Since the liver is the main organ that metabolizes chemicals, the LMNT is expected to detect clastogens, especially those that need metabolic activation in the liver, and aneugens. Based on current data the three methods seem to have a high sensitivity and specificity, but more data, especially on non-genotoxic but toxic substances, would be needed to fully evaluate the test performance. The three methods can be combined with the micronucleus test (MNT) using bone marrow (BM) and/or peripheral blood (PB). The ability of the PH method to detect both clastogens and aneugens has already been established, but the methodology is technically challenging. The JR method is relatively straightforward, but animal metabolism might not be fully comparable to adult animals, and data on aneugens are limited. These two methods also have the advantage of a short testing period. The RD method is also straightforward and can be integrated into repeated-dose (e.g. 2 or 4 weeks) toxicity studies, but again data on aneugens are limited. The working group concluded that the LMNT could be used as a second in vivo test when a relevant positive result in in vitro mammalian cell genotoxicity tests is noted (especially under the condition of metabolic activation), and a negative result is observed in the in vivo BM/PB-MNT. The group members discussed LMNT protocols and reached consensus about many aspects of test procedures. However, data gaps as mentioned above remain, and further data are needed to fully establish the LMNT protocol.
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Affiliation(s)
| | | | - Mirjam Luijten
- Centre for Health Protection, National Institute for Public Health and the Environment, (RIVM), Bilthoven, The Netherlands
| | | | - Shuichi Hamada
- LSI Medience (formerly Mitsubishi Chemical Medience Co.), Ibaraki, Japan
| | | | | | - Hironao Takasawa
- LSI Medience (formerly Mitsubishi Chemical Medience Co.), Ibaraki, Japan
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