1
|
Ji C, Miao J, Zhao N, Dai Y, Yang J, Qu J, Zhu J, Zhao M. N-nitrosamines induced gender-dimorphic effects on infant rats at environmental levels. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169196. [PMID: 38097075 DOI: 10.1016/j.scitotenv.2023.169196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 11/22/2023] [Accepted: 12/06/2023] [Indexed: 12/21/2023]
Abstract
The safety of drinking water has always been a concern for people all over the world. N-nitrosamines (NAs), a kind of nitrogenous disinfection by-products (N-DBPs), are generally detected as a mixture in drinking water at home and abroad. Studies have shown that individual NAs posed strong carcinogenicity at high concentrations. However, health risks of NAs at environmental levels (concentrations in drinking water) are still unclear. Therefore, the potential health risks of environmentally relevant NAs exposure in drinking water needs to be conducted. In this study, blood biochemical analysis and metabolomics based on nuclear magnetic resonance (NMR) were performed to comprehensively investigate NAs induced metabolic disturbance in infant rats at environmental levels. Results of blood biochemical indices analysis indicated that AST in the serum of male rats in NAs-treated group exhibited a significant gender-specific difference. Multivariate statistics showed that two and eight significantly disturbed metabolic pathways were identified in the serum samples of NAs-treated male and female rats, respectively. In the urine samples of NAs-treated female rats, glycine, serine, and threonine metabolism pathway was significantly disturbed; while three significantly disturbed metabolic pathways were found in the urine of NAs-treated male rats. Finally, results of spearman correlation coefficients suggested that the disturbances of metabolism profile in serum and urine were correlated with changes in the gut microbiota (data derived from our published paper). Data presented here aimed to generate new health risk data of NAs mixture exposure at environmental levels and provide theoretical support for drinking water safety management. ENVIRONMENTAL IMPLICATION: N-nitrosamines (NAs) are a kind of nitrogenous disinfection by-products (N-DBPs) generated during drinking water disinfection processes. Herein, health risks of NAs at environmental levels (concentrations in drinking water) are investigated using blood biochemical analysis and nuclear magnetic resonance (NMR)-based metabolomics. Results confirmed NAs induced gender-specific on the metabolism in rat and the disturbances of metabolism profile in serum and urine were correlated with changes in the gut microbiota. Data presented here aimed to generate new health risk data of NAs mixture exposure at environmental levels and provide theoretical support for drinking water safety management.
Collapse
Affiliation(s)
- Chenyang Ji
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy, Zhejiang Shuren University, Hangzhou 310015, China
| | - Jiahui Miao
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Nan Zhao
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Yaoyao Dai
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jiawen Yang
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jianli Qu
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jianqiang Zhu
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China; College of Life Science, Taizhou University, Taizhou 318000, PR China
| | - Meirong Zhao
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
| |
Collapse
|
2
|
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: 22] [Impact Index Per Article: 22.0] [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.
Collapse
|
3
|
Takasu S, Ishii Y, Namiki M, Nakamura K, Mitsumoto T, Takimoto N, Nohmi T, Ogawa K. Comprehensive analysis of the general toxicity, genotoxicity, and carcinogenicity of 3-acetyl-2,5-dimethylfuran in male gpt delta rats. Food Chem Toxicol 2023; 172:113544. [PMID: 36464108 DOI: 10.1016/j.fct.2022.113544] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 11/23/2022] [Accepted: 11/28/2022] [Indexed: 12/05/2022]
Abstract
The safety of flavoring agents has been evaluated according to classification by chemical structure and using a decision tree approach. The genotoxic potential found in some flavoring agents has highlighted the importance of efficient toxicity studies. We performed a comprehensive toxicity analysis using reporter gene transgenic rats to assess the safety of 3-acetyl-2,5-dimethylfuran (ADF), a flavoring agent exhibiting genotoxic potential in silico and in vitro assays. Male F344 gpt delta rats were given 0, 30, or 300 mg/kg body weight/day ADF by gavage for 13 weeks. In serum biochemistry analyses, triglyceride, total cholesterol, phospholipid, and total protein levels and albumin/globulin ratios were significantly altered in the 30 and 300 mg/kg groups. Histopathologically, nasal cavity toxicity and hepatocellular hypertrophy were observed in the 300 mg/kg group. In the livers of 300 mg/kg group, a significant increase in gpt mutant frequencies were observed along with ADF-specific DNA adduct formation. The number and area of glutathione S-transferase placental form-positive foci were significantly increased in the same group. Thus, ADF affected nasal cavity, liver, and lipid metabolism and showed genotoxicity and possible carcinogenicity in the liver. Overall, our comprehensive toxicity study using gpt delta rats provided insights into the safety evaluation of ADF.
Collapse
Affiliation(s)
- Shinji Takasu
- Division of Pathology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa, 210-9501, Japan
| | - Yuji Ishii
- Division of Pathology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa, 210-9501, Japan.
| | - Moeka Namiki
- Division of Pathology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa, 210-9501, Japan
| | - Kenji Nakamura
- Division of Pathology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa, 210-9501, Japan
| | - Tatsuya Mitsumoto
- Division of Pathology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa, 210-9501, Japan
| | - Norifumi Takimoto
- Division of Pathology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa, 210-9501, Japan; Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo, 183-8509, Japan
| | - Takehiko Nohmi
- Division of Pathology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa, 210-9501, Japan
| | - Kumiko Ogawa
- Division of Pathology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa, 210-9501, Japan
| |
Collapse
|
4
|
Toxicology and carcinogenesis studies of di(2-ethylhexyl) phthalate administered in feed to Sprague Dawley (Hsd:Sprague Dawley SD) rats. NATIONAL TOXICOLOGY PROGRAM TECHNICAL REPORT SERIES 2021:NTP-TR-601. [PMID: 35073286 PMCID: PMC8996106 DOI: 10.22427/ntp-tr-601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Di(2-ethylhexyl) phthalate (DEHP) is a member of the phthalate ester chemical class that occurs commonly in the environment and to which humans are widely exposed. Lifetime exposure to DEHP is likely to occur, including during the in utero and early postnatal windows of development. To date, no carcinogenicity assessments of DEHP have used a lifetime exposure paradigm that includes the perinatal period (gestation and lactation). The National Toxicology Program (NTP) tested the hypothesis that exposure during the perinatal period would alter the DEHP carcinogenic response quantitatively (more neoplasms) or qualitatively (different neoplasm types). Two chronic carcinogenicity assessments of DEHP were conducted in which Sprague Dawley (Hsd:Sprague Dawley SD) rats were exposed to dosed feed containing 0, 300, 1,000, 3,000, or 10,000 ppm DEHP for 2 years using different exposure paradigms. In Study 1, groups of 45 F0 time-mated females were provided dosed feed beginning on gestation day (GD) 6 through lactation. On postnatal day (PND) 21, groups of 50 F1 rats per sex continued on the study and were provided dosed feed containing the same DEHP concentration as their respective dam for 2 years. In Study 2, groups of 50 rats per sex, aged 6 to 7 weeks at study start, were provided dosed feed containing DEHP for 2 years. (Abstract Abridged).
Collapse
|
5
|
Nohmi T, Watanabe M. Mutagenicity of carcinogenic heterocyclic amines in Salmonella typhimurium YG strains and transgenic rodents including gpt delta. Genes Environ 2021; 43:38. [PMID: 34526143 PMCID: PMC8444484 DOI: 10.1186/s41021-021-00207-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 07/14/2021] [Indexed: 11/10/2022] Open
Abstract
Chemical carcinogens to humans have been usually identified by epidemiological studies on the relationships between occupational or environmental exposure to the agents and specific cancer induction. In contrast, carcinogenic heterocyclic amines were identified under the principle that mutagens in bacterial in the Ames test are possible human carcinogens. In the 1970s to 1990s, more than 10 heterocyclic amines were isolated from pyrolysates of amino acids, proteins, meat or fish as mutagens in the Ames test, and they were demonstrated as carcinogens in rodents. In the 1980s and 1990s, we have developed derivatives of the Ames tester strains that overexpressed acetyltransferase of Salmonella typhimurium. These strains such as Salmonella typhimurium YG1024 exhibited a high sensitivity to the mutagenicity of the carcinogenic heterocyclic amines. Because of the high sensitivity, YG1024 and other YG strains were used for various purposes, e.g., identification of novel heterocyclic amines, mechanisms of metabolic activation, comparison of mutagenic potencies of various heterocyclic amines, and the co-mutagenic effects. In the 1990s and 2000s, we developed transgenic mice and rats for the detection of mutagenicity of chemicals in vivo. The transgenics were generated by the introduction of reporter genes for mutations into fertilized eggs of mice and rats. We named the transgenics as gpt delta because the gpt gene of Escherichia coli was used for detection of point mutations such as base substitutions and frameshifts and the red/gam genes of λ phage were employed to detect deletion mutations. The transgenic rodents gpt delta and other transgenics with lacI or lacZ as reporter genes have been utilized for characterization of mutagenicity of heterocyclic amines in vivo. In this review, we summarized the in vitro mutagenicity of heterocyclic amines in Salmonella typhimurium YG strains and the in vivo mutagenicity in transgenic rodents. We discussed the relationships between in vitro and in vivo mutagenicity of the heterocyclic amines and their relations to the carcinogenicity.
Collapse
Affiliation(s)
- Takehiko Nohmi
- Division of Pathology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa 210-9501 Japan
| | - Masahiko Watanabe
- School of Pharmacy, Shujitsu University, 1-6-1 Nishigawara, Naka-ku, Okayama, 703-8516 Japan
| |
Collapse
|
6
|
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
|
7
|
Kirkland D, Kovochich M, More SL, Murray FJ, Monnot AD, Miller JV, Jaeschke H, Jacobson-Kram D, Deore M, Pitchaiyan SK, Unice K, Eichenbaum G. A comprehensive weight of evidence assessment of published acetaminophen genotoxicity data: Implications for its carcinogenic hazard potential. Regul Toxicol Pharmacol 2021; 122:104892. [PMID: 33592196 DOI: 10.1016/j.yrtph.2021.104892] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 02/03/2021] [Accepted: 02/09/2021] [Indexed: 11/17/2022]
Abstract
In 2019, the California Office of Environmental Health Hazard Assessment initiated a review of the carcinogenic hazard potential of acetaminophen, including an assessment of its genotoxicity. The objective of this analysis was to inform this review process with a weight-of-evidence assessment of more than 65 acetaminophen genetic toxicology studies that are of widely varying quality and conformance to accepted standards and relevance to humans. In these studies, acetaminophen showed no evidence of induction of point or gene mutations in bacterial and mammalian cell systems or in in vivo studies. In reliable, well-controlled test systems, clastogenic effects were only observed in unstable, p53-deficient cell systems or at toxic and/or excessively high concentrations that adversely affect cellular processes (e.g., mitochondrial respiration) and cause cytotoxicity. Across the studies, there was no clear evidence that acetaminophen causes DNA damage in the absence of toxicity. In well-controlled clinical studies, there was no meaningful evidence of chromosomal damage. Based on this weight-of-evidence assessment, acetaminophen overwhelmingly produces negative results (i.e., is not a genotoxic hazard) in reliable, robust high-weight studies. Its mode of action produces cytotoxic effects before it can induce the stable, genetic damage that would be indicative of a genotoxic or carcinogenic hazard.
Collapse
|
8
|
Matsushita K, Ishii Y, Kijima A, Takasu S, Kuroda K, Takagi H, Nohmi T, Ogawa K, Umemura T. Background data of 2-year-old male and female F344 gpt delta rats. J Toxicol Pathol 2021; 34:23-31. [PMID: 33627942 PMCID: PMC7890168 DOI: 10.1293/tox.2020-0060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 09/03/2020] [Indexed: 11/19/2022] Open
Abstract
Although gpt delta rats, as reporter gene-transgenic rats, were originally developed for in vivo mutation assays, they have also been used to evaluate chemical carcinogenesis and comprehensive toxicity. Therefore, it is necessary to accumulate background data on carcinogenicity and general toxicity in gpt delta rats. Here, we investigated the background data of 110-week-old male and female F344 gpt delta rats and wild-type rats. There was no effect of reporter gene transfection on animal survival rates and body weights during the experiment. The relative weight of male gpt delta rat adrenals was significantly higher than that of wild-type rats, possibly due to the higher incidence of pheochromocytoma. There were no intergenotype differences in the incidence of nonneoplastic lesions in both sexes, including chronic progressive nephropathy and focus of cellular alteration in the liver, which had a higher incidence in both genotypes. Additionally, the significantly higher incidence of adrenal pheochromocytoma in male gpt delta rats than that in wild-type rats was likely incidental because of the lack of differences in the incidences of preneoplastic (male and female) and neoplastic (female) adrenal lesions in both genotypes. Other neoplastic lesions in both sexes showed no intergenotype differences in incidence rates, although large granular lymphocytic leukemia in the spleen and Leydig cell tumors in the testes of males showed higher incidence rates. Overall, there were no effects of reporter gene transfection on the spectrum of spontaneous lesions in F344 gpt delta rats, thus supporting their applicability in evaluating chemical toxicity and carcinogenicity.
Collapse
Affiliation(s)
- Kohei Matsushita
- Division of Pathology, National Institute of Health
Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki, Kanagawa 210-9501, Japan
| | - Yuji Ishii
- Division of Pathology, National Institute of Health
Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki, Kanagawa 210-9501, Japan
| | - Aki Kijima
- Division of Pathology, National Institute of Health
Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki, Kanagawa 210-9501, Japan
| | - Shinji Takasu
- Division of Pathology, National Institute of Health
Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki, Kanagawa 210-9501, Japan
| | - Ken Kuroda
- Division of Pathology, National Institute of Health
Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki, Kanagawa 210-9501, Japan
| | - Hisayoshi Takagi
- Japan SLC, Inc., 3-5-1 Aoihigashi, Naka-ku, Hamamatsu,
Shizuoka 433-8114, Japan
| | - Takehiko Nohmi
- Division of Pathology, National Institute of Health
Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki, Kanagawa 210-9501, Japan
| | - Kumiko Ogawa
- Division of Pathology, National Institute of Health
Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki, Kanagawa 210-9501, Japan
| | - Takashi Umemura
- Division of Pathology, National Institute of Health
Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki, Kanagawa 210-9501, Japan
- Faculty of Animal Health Technology, Yamazaki University of
Animal Health Technology, 4-7-2 Minami-Osawa, Hachioji, Tokyo 192-0364, Japan
| |
Collapse
|
9
|
Takasu S, Ishii Y, Kijima A, Ogawa K, Nakane S, Umemura T. Furan Induced Characteristic Glutathione S-Transferase Placental Form-Positive Foci in Terms of Cell Kinetics and Gene Expression. Toxicol Pathol 2020; 48:756-765. [PMID: 32833602 DOI: 10.1177/0192623320948782] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Glutathione S-transferase placental form-positive (GST-P+) foci are markers of preneoplastic lesions in rat hepatocarcinogenesis. Our previous studies using reporter gene transgenic rats showed that furan, a hepatocarcinogen in rodents, rapidly induces the formation of GST-P+ foci after short exposure without reporter gene mutation. We hypothesized that GST-P+ foci induced by furan may have biological characteristics different from those induced by diethylnitrosamine (DEN), a genotoxic hepatocarcinogen. Accordingly, we compared the cell kinetics of GST-P+ foci after cessation of DEN treatment and performed comprehensive gene expression in DEN- or furan-induced GST-P+ foci. The number and area of DEN-induced GST-P+ foci were increased after cessation of treatment, whereas furan decreased these parameters. Size distribution analysis showed that large furan-induced GST-P+ foci disappeared after cessation of treatment. Hierarchical cluster analysis showed that all samples from GST-P+ foci induced by furan were separated from those induced by DEN. SOX9 expression was upregulated in furan-induced GST-P+ foci and was detected by immunohistochemistry in large furan-induced GST-P+ foci. Our results indicated that large furan-induced GST-P+ foci were quite different from DEN-induced GST-P+ foci at the molecular and cellular levels. And one of the properties of disappearing large GST-P+ foci were characterized by inclusion of hepatocytes expressing SOX9.
Collapse
Affiliation(s)
- Shinji Takasu
- Division of Pathology, 26360National Institute of Health Sciences, Kanagawa, Japan
| | - Yuji Ishii
- Division of Pathology, 26360National Institute of Health Sciences, Kanagawa, Japan
| | - Aki Kijima
- Division of Pathology, 26360National Institute of Health Sciences, Kanagawa, Japan
| | - Kumiko Ogawa
- Division of Pathology, 26360National Institute of Health Sciences, Kanagawa, Japan
| | - Sae Nakane
- Division of Pathology, 26360National Institute of Health Sciences, Kanagawa, Japan.,Faculty of Animal Health Technology, 183800Yamazaki University of Animal Health Technology, Tokyo, Japan
| | - Takashi Umemura
- Division of Pathology, 26360National Institute of Health Sciences, Kanagawa, Japan.,Faculty of Animal Health Technology, 183800Yamazaki University of Animal Health Technology, Tokyo, Japan
| |
Collapse
|
10
|
van der Leede B, Weiner S, Van Doninck T, De Vlieger K, Schuermans A, Tekle F, Geys H, van Heerden M, De Jonghe S, Van Gompel J. Testing of acetaminophen in support of the international multilaboratory in vivo rat Pig-a assay validation trial. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:508-525. [PMID: 32187737 PMCID: PMC7317746 DOI: 10.1002/em.22368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 03/09/2020] [Accepted: 03/13/2020] [Indexed: 06/10/2023]
Abstract
Acetaminophen, a nonmutagenic compound as previously concluded from bacteria, in vitro mammalian cell, and in vivo transgenic rat assays, presented a good profile as a nonmutagenic reference compound for use in the international multilaboratory Pig-a assay validation. Acetaminophen was administered at 250, 500, 1,000, and 2,000 mg·kg-1 ·day-1 to male Sprague Dawley rats once daily in 3 studies (3 days, 2 weeks, and 1 month with a 1-month recovery group). The 3-Day and 1-Month Studies included assessments of the micronucleus endpoint in peripheral blood erythrocytes and the comet endpoint in liver cells and peripheral blood cells in addition to the Pig-a assay; appropriate positive controls were included for each assay. Within these studies, potential toxicity of acetaminophen was evaluated and confirmed by inclusion of liver damage biomarkers and histopathology. Blood was sampled pre-treatment and at multiple time points up to Day 57. Pig-a mutant frequencies were determined in total red blood cells (RBCs) and reticulocytes (RETs) as CD59-negative RBC and CD59-negative RET frequencies, respectively. No increases in DNA damage as indicated through Pig-a, micronucleus, or comet endpoints were seen in treated rats. All positive controls responded as appropriate. Data from this series of studies demonstrate that acetaminophen is not mutagenic in the rat Pig-a model. These data are consistent with multiple studies in other nonclinical models, which have shown that acetaminophen is not mutagenic. At 1,000 mg·kg-1 ·day-1 , Cmax values of acetaminophen on Day 28 were 153,600 ng/ml and 131,500 ng/ml after single and repeat dosing, respectively, which were multiples over that of clinical therapeutic exposures (2.6-6.1 fold for single doses of 4,000 mg and 1,000 mg, respectively, and 11.5 fold for multiple dose of 4,000 mg) (FDA 2002). Data generated were of high quality and valid for contribution to the international multilaboratory validation of the in vivo Rat Pig-a Mutation Assay.
Collapse
Affiliation(s)
| | - Sandy Weiner
- Janssen Research & DevelopmentSpring House, PennsylvaniaUSA
| | | | | | | | - Fetene Tekle
- Janssen Research & DevelopmentBeerse, AntwerpBelgium
| | - Helena Geys
- Janssen Research & DevelopmentBeerse, AntwerpBelgium
| | | | | | | |
Collapse
|
11
|
Ito Y, Nakajima K, Masubuchi Y, Kikuchi S, Saito F, Akahori Y, Jin M, Yoshida T, Shibutani M. Expression Characteristics of Genes Hypermethylated and Downregulated in Rat Liver Specific to Nongenotoxic Hepatocarcinogens. Toxicol Sci 2020; 169:122-136. [PMID: 30690589 PMCID: PMC6484883 DOI: 10.1093/toxsci/kfz027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
This study examined hypermethylated and downregulated genes specific to carbon tetrachloride (CCl4) by Methyl-Seq analysis combined with expression microarray analysis in the liver of rats treated with CCl4 or N-nitrosodiethylamine (DEN) for 28 days, by excluding those with DEN. Among 52 genes, Ldlrad4, Proc, Cdh17, and Nfia were confirmed to show promoter-region hypermethylation by methylation-specific quantitative PCR analysis on day 28. The transcript levels of these 4 genes decreased by real-time reverse transcription-PCR analysis in the livers of rats treated with nongenotoxic hepatocarcinogens for up to 90 days compared with untreated controls and genotoxic hepatocarcinogens. Immunohistochemically, LDLRAD4 and PROC showed decreased immunoreactivity, forming negative foci, in glutathione S-transferase placental form (GST-P)+ foci, and incidences of LDLRAD4− and PROC− foci in GST-P+ foci induced by treatment with nongenotoxic hepatocarcinogens for 84 or 90 days were increased compared with those with genotoxic hepatocarcinogens. In contrast, CDH17 and NFIA responded to hepatocarcinogens without any relation to the genotoxic potential of carcinogens. All 4 genes did not respond to renal carcinogens after treatment for 28 days. Considering that Ldlrad4 is a negative regulator of transforming growth factor-β signaling, Proc participating in p21WAF1/CIP1 upregulation by activation, Cdh17 inducing cell cycle arrest by gene knockdown, and Nfia playing a role in a tumor-suppressor, all these genes may be potential in vivo epigenetic markers of nongenotoxic hepatocarcinogens from the early stages of treatment in terms of gene expression changes. LDLRAD4 and PROC may have a role in the development of preneoplastic lesions produced by nongenotoxic hepatocarcinogens.
Collapse
Affiliation(s)
- Yuko Ito
- Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan.,Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu-shi, Gifu, Japan
| | - Kota Nakajima
- Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan.,Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu-shi, Gifu, Japan
| | - Yasunori Masubuchi
- Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan.,Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu-shi, Gifu, Japan
| | - Satomi Kikuchi
- Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan.,Cooperative Division of Veterinary Sciences, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan
| | - Fumiyo Saito
- Chemicals Evaluation and Research Institute, Bunkyo-ku, Tokyo, Japan
| | - Yumi Akahori
- Chemicals Evaluation and Research Institute, Bunkyo-ku, Tokyo, Japan
| | - Meilan Jin
- Laboratory of Veterinary Pathology, College of Animal Science and Technology Veterinary Medicine, Southwest University, Chongqing, P.R. China
| | - Toshinori Yoshida
- Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan.,Cooperative Division of Veterinary Sciences, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan
| | - Makoto Shibutani
- Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan.,Cooperative Division of Veterinary Sciences, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan.,Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan
| |
Collapse
|
12
|
Ito Y, Nakajima K, Masubuchi Y, Kikuchi S, Saito F, Akahori Y, Jin M, Yoshida T, Shibutani M. Differential responses on energy metabolic pathway reprogramming between genotoxic and non-genotoxic hepatocarcinogens in rat liver cells. J Toxicol Pathol 2019; 32:261-274. [PMID: 31719753 PMCID: PMC6831489 DOI: 10.1293/tox.2019-0048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 06/25/2019] [Indexed: 12/12/2022] Open
Abstract
To clarify difference in the responses on the reprogramming of metabolism toward carcinogenesis between genotoxic and non-genotoxic hepatocarcinogens in the liver, rats were repeatedly administered genotoxic hepatocarcinogens (N-nitrosodiethylamine, aflatoxin B1, N-nitrosopyrrolidine, or carbadox) or non-genotoxic hepatocarcinogens (carbon tetrachloride, thioacetamide, or methapyrilene hydrochloride) for 28, 84, or 90 days. Non-genotoxic hepatocarcinogens revealed transcript expression changes suggestive of suppressed mitochondrial oxidative phosphorylation (OXPHOS) after 28 days and increased glutathione S-transferase placental form-positive (GST-P+) foci downregulating adenosine triphosphate (ATP) synthase subunit beta, mitochondrial precursor (ATPB), compared with genotoxic hepatocarcinogens after 84 or 90 days, suggesting that non-genotoxic hepatocarcinogens are prone to suppress OXPHOS from the early stage of treatment, which is in contrast to genotoxic hepatocarcinogens. Both genotoxic and non-genotoxic hepatocarcinogens upregulated glycolytic enzyme genes and increased cellular membrane solute carrier family 2, facilitated glucose transporter member 1 (GLUT1) expression in GST-P+ foci for up to 90 days, suggesting induction of a metabolic shift from OXPHOS to glycolysis at early hepatocarcinogenesis by hepatocarcinogens unrelated to genotoxic potential. Non-genotoxic hepatocarcinogens increased c-MYC+ cells after 28 days and downregulated Tp53 after 84 or 90 days, suggesting a commitment to enhanced metabolic shift and cell proliferation. Genotoxic hepatocarcinogens also enhanced c-MYC activation-related metabolic shift until 84 or 90 days. In addition, both genotoxic and non-genotoxic hepatocarcinogens upregulated glutaminolysis-related Slc1a5 or Gls, or both, after 28 days and induced liver cell foci immunoreactive for neutral amino acid transporter B(0) (SLC1A5) in the subpopulation of GST-P+ foci after 84 or 90 days, suggesting glutaminolysis-mediated facilitation of cell proliferation toward hepatocarcinogenesis. These results suggest differential responses between genotoxic and non-genotoxic hepatocarcinogens on reprogramming of energy metabolic pathways toward carcinogenesis in liver cells from the early stage of hepatocarcinogen treatment.
Collapse
Affiliation(s)
- Yuko Ito
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan.,Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu-shi, Gifu 501-1193, Japan
| | - Kota Nakajima
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan.,Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu-shi, Gifu 501-1193, Japan
| | - Yasunori Masubuchi
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan.,Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu-shi, Gifu 501-1193, Japan
| | - Satomi Kikuchi
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan.,Cooperative Division of Veterinary Sciences, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
| | - Fumiyo Saito
- Chemicals Evaluation and Research Institute, Japan, 1-4-25 Kouraku, Bunkyo-ku, Tokyo 112-0004, Japan
| | - Yumi Akahori
- Chemicals Evaluation and Research Institute, Japan, 1-4-25 Kouraku, Bunkyo-ku, Tokyo 112-0004, Japan
| | - Meilan Jin
- Laboratory of Veterinary Pathology, College of Animal Science and Technology Veterinary Medicine, Southwest University, No.2 Tiansheng Road, BeiBei District, Chongqing 400715, P.R. China
| | - Toshinori Yoshida
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan.,Cooperative Division of Veterinary Sciences, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
| | - Makoto Shibutani
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan.,Cooperative Division of Veterinary Sciences, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan.,Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
| |
Collapse
|
13
|
Totsuka Y, Lin Y, He Y, Ishino K, Sato H, Kato M, Nagai M, Elzawahry A, Totoki Y, Nakamura H, Hosoda F, Shibata T, Matsuda T, Matsushima Y, Song G, Meng F, Li D, Liu J, Qiao Y, Wei W, Inoue M, Kikuchi S, Nakagama H, Shan B. DNA Adductome Analysis Identifies N-Nitrosopiperidine Involved in the Etiology of Esophageal Cancer in Cixian, China. Chem Res Toxicol 2019; 32:1515-1527. [PMID: 31286759 DOI: 10.1021/acs.chemrestox.9b00017] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Yukari Totsuka
- Division of Carcinogenesis & Prevention, National Cancer Center Research Institute, Tokyo 104-0045, Japan
| | - Yingsong Lin
- Department of Public Health, Aichi Medical University School of Medicine, Nagakute 480-1195, Japan
| | - Yutong He
- Cancer Institute, The Fourth Hospital of Hebei Medical University/The Tumor Hospital of Hebei Province, Shijiazhuang 050011, China
| | - Kousuke Ishino
- Division of Carcinogenesis & Prevention, National Cancer Center Research Institute, Tokyo 104-0045, Japan
| | - Haruna Sato
- Division of Carcinogenesis & Prevention, National Cancer Center Research Institute, Tokyo 104-0045, Japan
| | - Mamoru Kato
- Department of Bioinformatics, National Cancer Center Research Institute, Tokyo 104-0045, Japan
| | - Momoko Nagai
- Department of Bioinformatics, National Cancer Center Research Institute, Tokyo 104-0045, Japan
| | - Asmaa Elzawahry
- Department of Bioinformatics, National Cancer Center Research Institute, Tokyo 104-0045, Japan
| | - Yasushi Totoki
- Division of Cancer Genomics, National Cancer Center Research Institute, Tokyo 104-0045, Japan
| | - Hiromi Nakamura
- Division of Cancer Genomics, National Cancer Center Research Institute, Tokyo 104-0045, Japan
| | - Fumie Hosoda
- Division of Cancer Genomics, National Cancer Center Research Institute, Tokyo 104-0045, Japan
| | - Tatsuhiro Shibata
- Division of Cancer Genomics, National Cancer Center Research Institute, Tokyo 104-0045, Japan
| | - Tomonari Matsuda
- Research Center for Environmental Quality Management, Kyoto University, Shiga 520-0811, Japan
| | - Yoshitaka Matsushima
- Department of Agricultural Chemistry, Tokyo University of Agriculture, Tokyo 156-8502, Japan
| | - Guohui Song
- Cixian Cancer Hospital, Cixian 056500, China
| | - Fanshu Meng
- Cixian Cancer Hospital, Cixian 056500, China
| | - Dongfang Li
- Cixian Cancer Hospital, Cixian 056500, China
| | - Junfeng Liu
- Cancer Institute, The Fourth Hospital of Hebei Medical University/The Tumor Hospital of Hebei Province, Shijiazhuang 050011, China
| | - Youlin Qiao
- Cancer Institute/Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100021, China
| | - Wenqiang Wei
- Cancer Institute/Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100021, China
| | - Manami Inoue
- Division of Prevention, Center for Public Health Sciences, National Cancer Center, Tokyo 104-0045, Japan
| | - Shogo Kikuchi
- Department of Public Health, Aichi Medical University School of Medicine, Nagakute 480-1195, Japan
| | | | - Baoen Shan
- Cancer Institute, The Fourth Hospital of Hebei Medical University/The Tumor Hospital of Hebei Province, Shijiazhuang 050011, China
| |
Collapse
|
14
|
Zhu J, Kong Y, Yu J, Shao S, Mao M, Zhao M, Yue S. Consumption of drinking water N-Nitrosamines mixture alters gut microbiome and increases the obesity risk in young male rats. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 248:388-396. [PMID: 30825764 DOI: 10.1016/j.envpol.2019.02.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 12/23/2018] [Accepted: 02/03/2019] [Indexed: 06/09/2023]
Abstract
N-nitrosamines (NAs) are an emerging group of disinfection by-products that occur as a mixture in drinking water. Although the potency of the individual NA components in drinking water is negligible, their combined effect is rarely reported. We tested whether multicomponent NAs mixtures at environmentally relevant levels would produce significant effects when each component was combined at extremely low concentrations i.e. a million times lower than its No Observed Effect Concentration (NOEC). Mixture L (the maximum values detected in drinking water) or mixture M (one order of magnitude higher than detected) were fed to male and female Sprague-Dawley (SD) rats since PND 28 for seven days. We found that the body weight gains and the triglyceride (TG) levels increased significantly in mixture M treated male rats. Correspondingly, an obesogenic microbiota profile was obtained in the mixture M treated young male rat: Firmicutes/Bacteroidetes and the obesity-related taxa including Alistipes, Ruminococcus were enriched. Collectively, this is the first in vivo demonstration of NAs mixtures at environmentally relevant levels. Despite the complicated relationship between gut microbiota and obesity, our study has demonstrated that changes in gut microbiota may contribute to the development of obesity after the exposure. Our results highlight that changes in gut microbiota could be a risk factor for obesity, which emphasizes the need to include gut microbiota in the traditional mammalian risk assessment.
Collapse
Affiliation(s)
- Jianqiang Zhu
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Research Center of Environmental Science, Zhejiang University of Technology, Hangzhou, 310032, China
| | - Yuan Kong
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Research Center of Environmental Science, Zhejiang University of Technology, Hangzhou, 310032, China
| | - Jie Yu
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Research Center of Environmental Science, Zhejiang University of Technology, Hangzhou, 310032, China
| | - Shuai Shao
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Research Center of Environmental Science, Zhejiang University of Technology, Hangzhou, 310032, China
| | - Manfei Mao
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Research Center of Environmental Science, Zhejiang University of Technology, Hangzhou, 310032, China
| | - Meirong Zhao
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Research Center of Environmental Science, Zhejiang University of Technology, Hangzhou, 310032, China
| | - Siqing Yue
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Research Center of Environmental Science, Zhejiang University of Technology, Hangzhou, 310032, China.
| |
Collapse
|
15
|
Nohmi T, Masumura K, Toyoda-Hokaiwado N. Transgenic rat models for mutagenesis and carcinogenesis. Genes Environ 2017; 39:11. [PMID: 28174618 PMCID: PMC5289047 DOI: 10.1186/s41021-016-0072-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Accepted: 12/08/2016] [Indexed: 01/18/2023] Open
Abstract
Rats are a standard experimental animal for cancer bioassay and toxicological research for chemicals. Although the genetic analyses were behind mice, rats have been more frequently used for toxicological research than mice. This is partly because they live longer than mice and induce a wider variety of tumors, which are morphologically similar to those in humans. The body mass is larger than mice, which enables to take samples from organs for studies on pharmacokinetics or toxicokinetics. In addition, there are a number of chemicals that exhibit marked species differences in the carcinogenicity. These compounds are carcinogenic in rats but not in mice. Such examples are aflatoxin B1 and tamoxifen, both are carcinogenic to humans. Therefore, negative mutagenic/carcinogenic responses in mice do not guarantee that the chemical is not mutagenic/carcinogenic to rats or perhaps to humans. To facilitate research on in vivo mutagenesis and carcinogenesis, several transgenic rat models have been established. In general, the transgenic rats for mutagenesis are treated with chemicals longer than transgenic mice for more exact examination of the relationship between mutagenesis and carcinogenesis. Transgenic rat models for carcinogenesis are engineered mostly to understand mechanisms underlying chemical carcinogenesis. Here, we review papers dealing with the transgenic rat models for mutagenesis and carcinogenesis, and discuss the future perspective.
Collapse
Affiliation(s)
- Takehiko Nohmi
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo, 158-8501 Japan
- Present address: Biological Safety Research Center, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo, 158-8501 Japan
| | - Kenichi Masumura
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo, 158-8501 Japan
| | - Naomi Toyoda-Hokaiwado
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo, 158-8501 Japan
| |
Collapse
|
16
|
Suzuki Y, Goto K, Nakayama Y, Saratani M, Takata T, Okamoto T, Okazaki S. Evaluation of a single-dose PIGRET assay for acetaminophen in rats compared with the RBC Pig-a assay. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2016; 811:16-20. [PMID: 27931808 DOI: 10.1016/j.mrgentox.2016.02.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Accepted: 02/22/2016] [Indexed: 11/25/2022]
Abstract
As a part of a collaborative study of the Pig-a assay by the Mammalian Mutagenicity Study Group of the Japanese Environmental Mutagen Society, a genotoxicity study on acetaminophen (APAP) was performed using the red blood cell (RBC) Pig-a and PIGRET assays. The dose levels were set at 0 (vehicle, 0.5% methylcellulose solution), 500, 1000, and 2000mg/kg, and APAP was administered once by oral gavage to male Sprague Dawley rats. For the positive control group, N-nitroso-N-ethylurea (ENU, 40mg/kg) was administered in the same way. The RBC Pig-a and PIGRET assays were performed using peripheral blood collected at pre-dosing and 1, 2 and 4 weeks after dosing. In both the RBC Pig-a and PIGRET assays, there were no changes in the Pig-a gene mutant frequency (MF) by the APAP treatment at any time point. The Pig-a MFs as measured by the RBC Pig-a assay for the ENU-treated group increased in a time-dependent manner with the maximum value at week 4; however, those using the PIGRET assay reached comparable values at week 1. Based on the above results, APAP was determined to have no mutagenicity under the conditions of this study, and the PIGRET assay could detect mutagenicity of ENU much earlier than the RBC Pig-a assay.
Collapse
Affiliation(s)
- Yuta Suzuki
- Gotemba Laboratory, BoZo Research Center Inc., 1284 Kamado, Gotemba-shi, Shizuoka 412-0039, Japan.
| | - Ken Goto
- Gotemba Laboratory, BoZo Research Center Inc., 1284 Kamado, Gotemba-shi, Shizuoka 412-0039, Japan
| | - Yoshihiro Nakayama
- Gotemba Laboratory, BoZo Research Center Inc., 1284 Kamado, Gotemba-shi, Shizuoka 412-0039, Japan
| | - Masatoshi Saratani
- Gotemba Laboratory, BoZo Research Center Inc., 1284 Kamado, Gotemba-shi, Shizuoka 412-0039, Japan
| | - Takuya Takata
- Gotemba Laboratory, BoZo Research Center Inc., 1284 Kamado, Gotemba-shi, Shizuoka 412-0039, Japan
| | - Takezo Okamoto
- Gotemba Laboratory, BoZo Research Center Inc., 1284 Kamado, Gotemba-shi, Shizuoka 412-0039, Japan
| | - Shuzo Okazaki
- Gotemba Laboratory, BoZo Research Center Inc., 1284 Kamado, Gotemba-shi, Shizuoka 412-0039, Japan
| |
Collapse
|
17
|
Fujioka M, Gi M, Kawachi S, Tatsumi K, Ishii N, Doi K, Kakehashi A, Wanibuchi H. Examination of in vivo mutagenicity of sodium arsenite and dimethylarsinic acid in gpt delta rats. J Environ Sci (China) 2016; 49:125-130. [PMID: 28007167 DOI: 10.1016/j.jes.2016.07.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 07/19/2016] [Accepted: 07/21/2016] [Indexed: 06/06/2023]
Abstract
Arsenic is a well-known human bladder and liver carcinogen, but its exact mechanism of carcinogenicity is not fully understood. Dimethylarsinic acid (DMAV) is a major urinary metabolite of sodium arsenite (iAsIII) and induces urinary bladder cancers in rats. DMAV and iAsIII are negative in in vitro mutagenicity tests. However, their in vivo mutagenicities have not been determined. The purpose of present study is to evaluate the in vivo mutagenicities of DMAV and iAsIII in rat urinary bladder epithelium and liver using gpt delta F344 rats. Ten-week old male gpt delta F344 rats were randomized into 3 groups and administered 0, 92mg/L DMAV, or 87mg/L iAsIII (each 50mg/L As) for 13weeks in the drinking water. In the mutation assay, point mutations are detected in the gpt gene by 6-thioguanine selection (gpt assay) and deletion mutations are identified in the red/gam genes by Spi- selection (Spi- assay). Results of the gpt and Spi- assays showed that DMAV and iAsIII had no effects on the mutant frequencies or mutation spectrum in urinary bladder epithelium or liver. These findings indicate that DMAV and iAsIII are not mutagenic in urinary bladder epithelium or liver in rats.
Collapse
Affiliation(s)
- Masaki Fujioka
- Department of Molecular Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, 545-8585, Osaka, Japan.
| | - Min Gi
- Department of Molecular Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, 545-8585, Osaka, Japan
| | - Satoko Kawachi
- Department of Molecular Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, 545-8585, Osaka, Japan
| | - Kumiko Tatsumi
- Department of Molecular Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, 545-8585, Osaka, Japan
| | - Naomi Ishii
- Department of Molecular Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, 545-8585, Osaka, Japan
| | - Kenichiro Doi
- Department of Molecular Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, 545-8585, Osaka, Japan
| | - Anna Kakehashi
- Department of Molecular Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, 545-8585, Osaka, Japan
| | - Hideki Wanibuchi
- Department of Molecular Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, 545-8585, Osaka, Japan.
| |
Collapse
|
18
|
Bogen KT, Heilman JM. Reassessment of MTBE cancer potency considering modes of action for MTBE and its metabolites. Crit Rev Toxicol 2016; 45 Suppl 1:1-56. [PMID: 26414780 DOI: 10.3109/10408444.2015.1052367] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
A 1999 California state agency cancer potency (CP) evaluation of methyl tert-butyl ether (MTBE) assumed linear risk extrapolations from tumor data were plausible because of limited evidence that MTBE or its metabolites could damage DNA, and based such extrapolations on data from rat gavage and rat and mouse inhalation studies indicating elevated tumor rates in male rat kidney, male rat Leydig interstitial cells, and female rat leukemia/lymphomas. More recent data bearing on MTBE cancer potency include a rodent cancer bioassay of MTBE in drinking water; several new studies of MTBE genotoxicity; several similar evaluations of MTBE metabolites, formaldehyde, and tert-butyl alcohol or TBA; and updated evaluations of carcinogenic mode(s) of action (MOAs) of MTBE and MTBE metabolite's. The lymphoma/leukemia data used in the California assessment were recently declared unreliable by the U.S. Environmental Protection Agency (EPA). Updated characterizations of MTBE CP, and its uncertainty, are currently needed to address a variety of decision goals concerning historical and current MTBE contamination. To this end, an extensive review of data sets bearing on MTBE and metabolite genotoxicity, cytotoxicity, and tumorigenicity was applied to reassess MTBE CP and related uncertainty in view of MOA considerations. Adopting the traditional approach that cytotoxicity-driven cancer MOAs are inoperative at very low, non-cytotoxic dose levels, it was determined that MTBE most likely does not increase cancer risk unless chronic exposures induce target-tissue toxicity, including in sensitive individuals. However, the corresponding expected (or plausible upper bound) CP for MTBE conditional on a hypothetical linear (e.g., genotoxic) MOA was estimated to be ∼2 × 10(-5) (or 0.003) per mg MTBE per kg body weight per day for adults exposed chronically over a lifetime. Based on this conservative estimate of CP, if MTBE is carcinogenic to humans, it is among the weakest 10% of chemical carcinogens evaluated by EPA.
Collapse
|
19
|
Masumura K, Sakamoto Y, Kumita W, Honma M, Nishikawa A, Nohmi T. Genomic integration of lambda EG10 transgene in gpt delta transgenic rodents. Genes Environ 2015; 37:24. [PMID: 27350819 PMCID: PMC4918054 DOI: 10.1186/s41021-015-0024-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 10/20/2015] [Indexed: 01/25/2023] Open
Abstract
Background Transgenic gpt delta mouse and rat models were developed to perform gpt and Spi− assays for in vivo mutagenicity tests. The animals were established by integration of lambda EG10 phage DNA as a transgene into the genome. The inserted position of the transgene on chromosome was determined by fluorescent in situ hybridization and Southern blot analyses; however, the exact position and sequence of the inserted junction were not known. To identify the site and pattern of genomic integration of the transgene copies, genomic DNAs extracted from C57BL/6J gpt delta mice and F344 gpt delta rats were applied to whole genome sequencing and mate-pair analysis. Results The result confirmed that multi-copy lambda EG10 transgenes are inserted at a single position in the mouse chromosome 17. The junction contains 70 bp of overlapped genomic sequences, and it has short homology at both ends. A copy number analysis suggested that the inserted transgenes may contain 41 head-to-tail junctions and 16 junctions of other types such as rearranged abnormal junctions. It suggested that the number of intact copies could be approximately 40 at maximum. In the F344 gpt delta rats, transgenes are inserted at a single position in the rat chromosome 4. The junction contains no overlapped sequence but 72-kb genomic sequence including one gene was deleted. The inserted transgenes may contain 15 head-to-tail junctions and two rearranged junctions. It suggested that the number of intact copies could be 14 at maximum. One germline base substitution in the gpt gene rescued from gpt delta rats was characterized. Conclusions The exact inserted positions of the lambda EG10 transgene in the genome of gpt delta transgenic rodents were identified. The copy number and arrangement of the transgene were analyzed. PCR primers for quick genotyping of gpt delta mice and rats have been designed. Electronic supplementary material The online version of this article (doi:10.1186/s41021-015-0024-6) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Kenichi Masumura
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 Japan
| | - Yasuteru Sakamoto
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 Japan ; Present address: Ajinomoto co., inc., Material Development & Application Labs, Research Institute For Bioscience Products & Fine Chemicals, 1-1 Suzuki-cho Kawasaki-ku, Kawasaki-shi, 210-8681 Kanagawa Japan
| | - Wakako Kumita
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 Japan
| | - Masamitsu Honma
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 Japan
| | - Akiyoshi Nishikawa
- Biological Safety Research Center, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 Japan
| | - Takehiko Nohmi
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 Japan ; Biological Safety Research Center, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 Japan
| |
Collapse
|
20
|
Ogawa I, Hagioa S, Furukawa S, Abe M, Kuroda Y, Hayashi S, Wako Y, Kawasako K. Evaluation of repeated dose micronucleus assays of the liver using N-nitrosopyrrolidine: a report of the collaborative study by CSGMT/JEMS.MMS. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2015; 780-781:25-30. [PMID: 26065307 DOI: 10.1016/j.mrgentox.2014.05.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The repeated dose liver micronucleus (RDLMN) assay has the potential to detect liver carcinogens, and can be integrated into a general toxicological study. To assess the performance of the assay, N-nitrosopyrrolidine (NPYR), a genotoxic hepatocarcinogen, was tested in 14- or 28-day RDLMN assays. NPYR was orally administered to rats at a daily dose of 25, 50 or 100 mg/kg. One day after the last administration, a portion of the liver was removed and hepatocyte micronucleus (MN) specimens were prepared by the new method recently established by Narumi et al. In addition, a bone marrow MN assay and a histopathological examination of the liver were conducted. The detection of Phospho-Histone H3 was performed by immunohistochemistry to evaluate the proliferation rate of hepatocytes. The results showed significant increase in the number of micronucleated hepatocytes and Phospho-Histone H3-positive cells from the lowest dose in both 14- and 28-day RDLMN assays. On the other hand, the bone marrow MN assay yielded a negative result, which was in accordance with the existing report of the bone marrow MN assay using mice. Upon histopathological examination, inflammatory lesions and hypertrophy were noted, which may explain the increase in the hepatocyte proliferation and the enhancement of MN induction by NPYR. Our findings indicate that the RDLMN assay could be a useful tool for comprehensive risk assessment of carcinogenicity by providing information on both genotoxicity and histopathology when integrated into a general repeat dosing toxicity assay.
Collapse
|
21
|
Akagi JI, Toyoda T, Cho YM, Mizuta Y, Nohmi T, Nishikawa A, Ogawa K. Validation study of the combined repeated-dose toxicity and genotoxicity assay using gpt delta rats. Cancer Sci 2015; 106:529-41. [PMID: 25683344 PMCID: PMC4452153 DOI: 10.1111/cas.12634] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 01/21/2015] [Accepted: 02/08/2015] [Indexed: 11/28/2022] Open
Abstract
Transgenic rodents carrying reporter genes to detect organ-specific in vivo genetic alterations are useful for risk assessment of genotoxicity that causes cancer. Thus, the Organization for Economic Co-operation and Development has established the guideline for genotoxicity tests using transgenic animals, which may be combined with repeated-dose toxicity studies. Here, we provide evidence to support equivalence of gpt delta and wild type (WT) rats in terms of toxicological responses to a genotoxic hepatocarcinogen, N-nitrosodiethylamine (DEN), and a non-genotoxic hepatocarcinogen, di(2-ethylhexyl)phthalate (DEHP). gpt delta rats treated with DEHP showed similar increases in liver and kidney weights, serum albumin, albumin/globulin ratios, and incidence of diffuse hepatocyte hypertrophy compared to WT F344 and Sprague-Dawley (SD) rats. DEN-treated gpt delta rats showed equivalent increases in the number and area of precancerous GST-P-positive foci in the liver compared to WT rats. The livers of DEN-treated gpt delta rats also showed increased frequencies of gpt and Spi(-) mutations; such changes were not observed in DEHP-treated gpt delta rats. These results indicated that gpt delta rats (both F344 and SD backgrounds) showed comparable DEHP-induced toxicity and DEN-induced genotoxicity to those observed in WT rats. With regard to the administration period, the general toxicity of 1.2% DEHP was evident throughout the experimental period, and the genotoxicity of 10 p.p.m. DEN could be detected after 2 weeks of administration and further increased at 4 weeks. These results suggested that combined assays using gpt delta rats could detect both general toxicity and genotoxicity by the canonical 4-week administration protocol. Therefore, this assay using gpt delta rats would be applicable for risk assessment including early detection of genotoxic carcinogens and ultimately serve to reduce cancer risks in humans from environmental chemicals.
Collapse
Affiliation(s)
- Jun-ichi Akagi
- Division of Pathology, National Institute of Health SciencesTokyo, Japan
| | - Takeshi Toyoda
- Division of Pathology, National Institute of Health SciencesTokyo, Japan
| | - Young-Man Cho
- Division of Pathology, National Institute of Health SciencesTokyo, Japan
| | - Yasuko Mizuta
- Division of Pathology, National Institute of Health SciencesTokyo, Japan
| | - Takehiko Nohmi
- Biological Safety Research Center, National Institute of Health SciencesTokyo, Japan
- Center for Innovative Drug Discovery and Development, National Institute of Biomedical InnovationTokyo, Japan
| | - Akiyoshi Nishikawa
- Biological Safety Research Center, National Institute of Health SciencesTokyo, Japan
| | - Kumiko Ogawa
- Division of Pathology, National Institute of Health SciencesTokyo, Japan
| |
Collapse
|
22
|
|
23
|
Kawamura Y, Hayashi H, Kurata Y, Hiratsuka K, Masumura K, Nohmi T. Evaluation of the genotoxicity of tamoxifen in the liver and kidney of F344 gpt delta transgenic rat in 3-week and 13-week repeated dose studies. Toxicology 2013; 312:56-62. [PMID: 23907062 DOI: 10.1016/j.tox.2013.07.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 07/12/2013] [Accepted: 07/20/2013] [Indexed: 12/18/2022]
Abstract
Transgenic rat gene mutation assays can be used to assess genotoxicity of chemicals in target organs for carcinogenicity. Mutations in transgenes are genetically neutral and accumulate during a treatment period; thus, the assays are suitable for assessment of the genotoxicity risk of chemicals using a repeated-dose treatment paradigm. However, few such studies have been conducted. To examine the utility of the transgenic rat assays in repeated-dose studies, we treated female F344 gpt delta rats with tamoxifen (TAM) at 20 and 40mg/kg, or toremifene (TOR) at 40mg/kg by gavage daily for 3 weeks. We also fed gpt delta rats with TAM at either 250ppm (15.4-17.6mg/kg) or 500ppm (30.0-32.9mg/kg) for 13 weeks. TAM is carcinogenic in the rat liver and TOR is not carcinogenic. TAM administration significantly increased gpt (point mutations) and Spi(-) (deletions) mutant frequencies (MFs) in the liver, the target organ of carcinogenesis; MFs were higher after treatment for 13 weeks than after treatment for 3 weeks. The MFs in the kidney did not increase in any of the TAM treatment groups. TOR had no effect on MFs (gpt and Spi(-)) in either the liver or the kidney. We conclude that the gpt delta rat assay in the repeated-dose treatment paradigm is sensitive enough to detect gene mutations induced by TAM in the target organ for carcinogenesis. Furthermore, the assay can be integrated into a 13-week dose-finding study for a 2-year cancer bioassay.
Collapse
Affiliation(s)
- Yuji Kawamura
- Toxicology Laboratory, Pharmaceutical Research Center, Meiji Seika Pharma Co., Ltd., 760 Morooka-cho, Kohoku-ku, Yokohama 222-8567, Japan.
| | | | | | | | | | | |
Collapse
|
24
|
Matsushita K, Kijima A, Ishii Y, Takasu S, Jin M, Kuroda K, Kawaguchi H, Miyoshi N, Nohmi T, Ogawa K, Umemura T. Development of a Medium-term Animal Model Using gpt Delta Rats to Evaluate Chemical Carcinogenicity and Genotoxicity. J Toxicol Pathol 2013; 26:19-27. [PMID: 23723564 PMCID: PMC3620210 DOI: 10.1293/tox.26.19] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 11/06/2012] [Indexed: 12/19/2022] Open
Abstract
In this study, the potential for development of an animal model (GPG46) capable of rapidly detecting chemical carcinogenicity and the underlying mechanisms of action were examined in gpt delta rats using a reporter gene assay to detect mutations and a medium-term rat liver bioassay to detect tumor promotion. The tentative protocol for the GPG46 model was developed based on the results of dose-response exposure to diethylnitrosamine (DEN) and treatment with phenobarbital over time following DEN administration. Briefly, gpt delta rats were exposed to various chemicals for 4 weeks, followed by a partial hepatectomy (PH) to collect samples for an in vivo mutation assay. The mutant frequencies (MFs) of the reporter genes were examined as an indication of tumor initiation. A single intraperitoneal (ip) injection of 10 mg/kg DEN was administered to rats 18 h after the PH to initiate hepatocytes. Tumor-promoting activity was evaluated based on the development of glutathione S-transferase placental form (GST-P)-positive foci at week 10. The genotoxic carcinogens 2-acetylaminofluorene (2-AAF), 2-amino-3-methylimidazo [4,5-f] quinolone (IQ) and safrole (SF), the non-genotoxic carcinogens piperonyl butoxide (PBO) and phenytoin (PHE), the non-carcinogen acetaminophen (APAP) and the genotoxic non-hepatocarcinogen aristolochic acid (AA) were tested to validate the GPG46 model. The validation results indicate that the GPG46 model could be a powerful tool in understanding chemical carcinogenesis and provide valuable information regarding human risk hazards.
Collapse
Affiliation(s)
- Kohei Matsushita
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
|
26
|
Suzuki Y, Umemura T, Ishii Y, Hibi D, Inoue T, Jin M, Sakai H, Kodama Y, Nohmi T, Yanai T, Nishikawa A, Ogawa K. Possible involvement of sulfotransferase 1A1 in estragole-induced DNA modification and carcinogenesis in the livers of female mice. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2012; 749:23-8. [DOI: 10.1016/j.mrgentox.2012.07.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Revised: 07/25/2012] [Accepted: 07/27/2012] [Indexed: 11/29/2022]
|
27
|
Huang XF, Li Y, Gu YH, Liu M, Xu Y, Yuan Y, Sun F, Zhang HQ, Shi HJ. The effects of Di-(2-ethylhexyl)-phthalate exposure on fertilization and embryonic development in vitro and testicular genomic mutation in vivo. PLoS One 2012; 7:e50465. [PMID: 23226291 PMCID: PMC3511574 DOI: 10.1371/journal.pone.0050465] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Accepted: 10/23/2012] [Indexed: 01/11/2023] Open
Abstract
The present study was undertaken to determine the reproductive hazards of Di-(2-ethylhexyl)-phthalate (DEHP) on mouse spermatozoa and embryos in vitro and genomic changes in vivo. Direct low-level DEHP exposure (1 μg/ml) on spermatozoa and embryos was investigated by in vitro fertilization (IVF) process, culture of preimplanted embryos in DEHP-supplemented medium and embryo transfer to achieve full term development. Big Blue® transgenic mouse model was employed to evaluate the mutagenesis of testicular genome with in vivo exposure concentration of DEHP (500 mg/kg/day). Generally, DEHP-treated spermatozoa (1 μg/ml, 30 min) presented reduced fertilization ability (P<0.05) and the resultant embryos had decreased developmental potential compared to DMSO controls (P<0.05). Meanwhile, the transferred 2-cell stage embryos derived from treated spermatozoa also exhibited decreased birth rate than that of control (P<0.05). When fertilized oocytes or 2-cell stage embryos were recovered by in vivo fertilization (without treatment) and then exposed to DEHP, the subsequent development proceed to blastocysts was different, fertilized oocytes were significantly affected (P<0.05) whereas developmental progression of 2-cell stage embryos was similar to controls (P>0.05). Testes of the Big Blue® transgenic mice treated with DEHP for 4 weeks indicated an approximately 3-fold increase in genomic DNA mutation frequency compared with controls (P<0.05). These findings unveiled the hazardous effects of direct low-level exposure of DEHP on spermatozoa's fertilization ability as well as embryonic development, and proved that in vivo DEHP exposure posed mutagenic risks in the reproductive organ – at least in testes, are of great concern to human male reproductive health.
Collapse
Affiliation(s)
- Xue-Feng Huang
- Shanghai Medical College, Fudan University, Shanghai, China
- Reproductive Medical Center, The First Affiliated Hospital of Wenzhou Medical College, Wenzhou, China
- * E-mail: (HJS); (XFH)
| | - Yan Li
- Reproductive Medical Center, The First Affiliated Hospital of Wenzhou Medical College, Wenzhou, China
| | - Yi-Hua Gu
- National Population and Family Planning Key Laboratory of Contraceptive Drugs and Devices, Shanghai Institute of Planned Parenthood Research, Shanghai, China
| | - Miao Liu
- Shanghai Medical College, Fudan University, Shanghai, China
| | - Yan Xu
- Shanghai Medical College, Fudan University, Shanghai, China
| | - Yao Yuan
- National Population and Family Planning Key Laboratory of Contraceptive Drugs and Devices, Shanghai Institute of Planned Parenthood Research, Shanghai, China
| | - Fei Sun
- Laboratory for Reproductive Biology, School of Life Science, University of Science and Technology of China, Hefei, China
| | - Hui-Qin Zhang
- Shanghai Medical College, Fudan University, Shanghai, China
- National Population and Family Planning Key Laboratory of Contraceptive Drugs and Devices, Shanghai Institute of Planned Parenthood Research, Shanghai, China
| | - Hui-Juan Shi
- Shanghai Medical College, Fudan University, Shanghai, China
- National Population and Family Planning Key Laboratory of Contraceptive Drugs and Devices, Shanghai Institute of Planned Parenthood Research, Shanghai, China
- * E-mail: (HJS); (XFH)
| |
Collapse
|
28
|
Xie XL, Wei M, Kakehashi A, Yamano S, Okabe K, Tajiri M, Wanibuchi H. Dammar resin, a non-mutagen, inducts oxidative stress and metabolic enzymes in the liver of gpt delta transgenic mouse which is different from a mutagen, 2-amino-3-methylimidazo[4,5-f]quinoline. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2012; 748:29-35. [DOI: 10.1016/j.mrgentox.2012.06.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Revised: 06/06/2012] [Accepted: 06/23/2012] [Indexed: 10/28/2022]
|
29
|
Caldwell JC. DEHP: Genotoxicity and potential carcinogenic mechanisms—A review. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2012; 751:82-157. [DOI: 10.1016/j.mrrev.2012.03.001] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 03/22/2012] [Accepted: 03/22/2012] [Indexed: 10/28/2022]
|
30
|
Possible involvement of genotoxic mechanisms in estragole-induced hepatocarcinogenesis in rats. Arch Toxicol 2012; 86:1593-601. [DOI: 10.1007/s00204-012-0865-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 04/26/2012] [Indexed: 11/26/2022]
|
31
|
Haighton LA, Lynch BS, Magnuson BA, Nestmann ER. A reassessment of risk associated with dietary intake of ochratoxin A based on a lifetime exposure model. Crit Rev Toxicol 2012; 42:147-68. [PMID: 22276591 PMCID: PMC3310481 DOI: 10.3109/10408444.2011.636342] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 10/25/2011] [Accepted: 10/26/2011] [Indexed: 12/23/2022]
Abstract
Mycotoxins, such as ochratoxin A (OTA), can occur from fungal growth on foods. OTA is considered a possible risk factor for adverse renal effects in humans based on renal tumors in male rats. For risk mitigation, Health Canada proposed maximum limits (MLs) for OTA based largely on a comparative risk assessment conducted by Health Canada (Kuiper-Goodman et al., 2010), in which analytical data of OTA in foods were used to determine the possible impact adopting MLs may have on OTA risks. The EU MLs were used for comparison and resultant risk was determined based on age-sex strata groups. These data were reevaluated here to determine comparative risk on a lifetime basis instead of age strata. Also, as there is scientific disagreement over the mechanism of OTA-induced renal tumors, mechanistic data were revisited. On a lifetime basis, risks associated with dietary exposure were found to be negligible, even without MLs, with dietary exposures to OTA three to four orders of magnitude below the pivotal animal LOAEL and the TD(05). Our review of the mechanistic data supported a threshold-based mechanism as the most plausible. In particular, OTA was negative in genotoxicity assays with the highest specificity and levels of DNA adducts were very low and not typical of genotoxic carcinogens. In conclusion, OTA exposures from Canadian foods do not present a significant cancer risk.
Collapse
Affiliation(s)
- Lois A Haighton
- Cantox Health Sciences International, An Intertek Company, Mississauga, Ontario, Canada.
| | | | | | | |
Collapse
|
32
|
Hecht SS, Upadhyaya P, Wang M. Evolution of research on the DNA adduct chemistry of N-nitrosopyrrolidine and related aldehydes. Chem Res Toxicol 2011; 24:781-90. [PMID: 21480629 PMCID: PMC3118975 DOI: 10.1021/tx200064a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
This perspective reviews our work on the identification of DNA adducts of N-nitrosopyrrolidine and some related aldehydes. The research began as a focused project to investigate mechanisms of cyclic nitrosamine carcinogenesis but expanded into other areas, as aldehyde metabolites of NPYR were shown to have their own diverse DNA adduct chemistry. A total of 69 structurally distinct DNA adducts were identified, and some of these, found in human tissues, have provided intriguing leads for investigating carcinogenesis mechanisms in humans due to exposure to both endogenous and exogenous agents.
Collapse
Affiliation(s)
- Stephen S Hecht
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, United States.
| | | | | |
Collapse
|
33
|
Tasaki M, Umemura T, Suzuki Y, Hibi D, Inoue T, Okamura T, Ishii Y, Maruyama S, Nohmi T, Nishikawa A. Oxidative DNA damage and reporter gene mutation in the livers of gpt delta rats given non-genotoxic hepatocarcinogens with cytochrome P450-inducible potency. Cancer Sci 2010; 101:2525-30. [PMID: 20735435 PMCID: PMC11159437 DOI: 10.1111/j.1349-7006.2010.01705.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Previous reports have proposed that reactive oxygen species resulting from induction of cytochrome P450 (CYP) isozymes might be involved in the modes of action of hepatocarcinogens with CYP-inducible potency. In the present study, we investigated 8-hydroxydeoxyguanosine (8-OHdG) levels, in vivo mutagenicity and glutathione S-transferase placental form (GST-P)-positive foci in the livers of gpt delta rats treated with piperonyl butoxide (PBO) or phenobarbital (PhB) for 4 and 13 weeks. Significant elevations in Cyp 1A1 and Cyp 1A2 mRNA levels after PBO treatment, and in Cyp 2B1 mRNA levels after PBO or PhB treatment, appeared together with remarkable hepatomegaly through the experimental period. Time-dependent and statistically significant increases in 8-OHdG levels were observed in the PBO treatment group along with significant increases in proliferating cell nuclear antigen (PCNA)-positive hepatocytes at 4 weeks, while no increase in 8-OHdG levels was found in PhB-treated rats. No changes in mutant frequencies of gpt and red/gam (Spi(-)) genes in liver DNA from PBO- or PhB-treated rats were observed at 4 or 13 weeks. A 13-week exposure to either PBO or PhB did not affect the number and area of GST-P-positive hepatocytes. CYP 1A1 and 1A2 induction may be responsible for elevated levels of 8-OHdG in PBO-treated rats. However, neither GC:TA transversions nor deletion mutations, typically regarded as 8-OHdG-related mutations, were observed in any of the treated rats. We conclude that reactive oxygen species, possibly produced through CYP catalytic pathways, likely induced genomic DNA damage but did not give rise to permanent gene mutation.
Collapse
Affiliation(s)
- Masako Tasaki
- Division of Pathology, National Institute of Health Sciences, Kamiyoga, Setagaya-ku, Tokyo, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Okamura T, Ishii Y, Suzuki Y, Inoue T, Tasaki M, Kodama Y, Nohmi T, Mitsumori K, Umemura T, Nishikawa A. Enhancing effects of carbon tetrachloride on in vivo mutagenicity in the liver of mice fed 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx). J Toxicol Sci 2010; 35:709-20. [PMID: 20930465 DOI: 10.2131/jts.35.709] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Chronic stimulus subsequent to cell injury plays an important role in cancer development, but the precise mechanisms remain unknown partly because appropriate animal models are lacking. In the present study, the effects of hepatotoxicant carbon tetrachloride (CCl(4)) on in vivo mutagenicity were investigated using gpt delta mice with or without p53. Female B6C3F(1) p53-proficient or -deficient gpt delta mice were given a diet containing 300 ppm of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) for 13 weeks, concurrently with intraperitoneal injection of 1 ml/kg CCl(4) solution once a week. Mutant frequencies of gpt and red/gam in p53-proficient mice fed MeIQx were both significantly elevated by CCl(4)co-treatment. Enhancing effects of CCl(4) treatment were also noted in p53-deficient mice. In the mutation spectra analysis of gpt mutant colonies, G:C to T:A transversions were predominantly observed regardless of CCl(4) injection, and clonal expansion of gpt colonies were increased in the co-treated group as compared with MeIQx alone group. The present data showing no significant changes in mRNA expression levels of CYP1A2 and GSTa4 between MeIQx-treated groups with and without CCl(4). In the Western blotting analysis, CYP1A2 protein levels were significantly decreased in the co-treated group as compared to MeIQx alone group, and GSTα protein levels were not changed among any groups. It is suggested that the mutant frequency by co-treatment with CCl(4) might result from some factors other than p53 or MeIQx metabolism/excretion. Thus, our data clearly demonstrate that this model could be a powerful tool for identifying the mechanisms underlying combinatorial effects on carcinogenesis.
Collapse
Affiliation(s)
- Toshiya Okamura
- Division of Pathology, National Institute of Health Sciences, Tokyo, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Loureiro APM, Zhang W, Kassie F, Zhang S, Villalta PW, Wang M, Hecht SS. Mass spectrometric analysis of a cyclic 7,8-butanoguanine adduct of N-nitrosopyrrolidine: comparison to other N-nitrosopyrrolidine adducts in rat hepatic DNA. Chem Res Toxicol 2010; 22:1728-35. [PMID: 19761253 DOI: 10.1021/tx900238t] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The well established rat hepatocarcinogen N-nitrosopyrrolidine (NPYR, 1) requires metabolic activation to DNA adducts to express its carcinogenic activity. Among the NPYR-DNA adducts that have been identified, the cyclic 7,8-butanoguanine adduct 2-amino-6,7,8,9-tetrahydro-9-hydroxypyrido[2,1-f]purine-4(3H)-one (6) has been quantified using moderately sensitive methods, but its levels have never been compared to those of other DNA adducts of NPYR in rat hepatic DNA. Therefore, in this study, we developed a sensitive new LC-ESI-MS/MS-SRM method for the quantitation of adduct 6 and compared its levels to those of several other NPYR-DNA adducts formed by different mechanisms. The new method was shown to be accurate and precise, with good recoveries and low fmol detection limits. Rats were treated with NPYR by gavage at doses of 46, 92, or 184 mg/kg body weight and sacrificed 16 h later. Hepatic DNA was isolated and analyzed for NPYR-DNA adducts. Adduct 6 was by far the most prevalent, with levels ranging from about 900-3000 micromol/mol Gua and responsive to dose. Levels of adducts formed from crotonaldehyde, a metabolite of NPYR, were about 0.2-0.9 micromol/mol dGuo, while those of adducts resulting from reaction with DNA of tetrahydrofuranyl-like intermediates were in the range of 0.01-4 micromol/mol deoxyribonucleoside. The results of this study demonstrate that, among typical NPYR-DNA adducts, adduct 6 is easily the most abundant in hepatic DNA. Since previous studies have shown that it can be detected in the urine of NPYR-treated rats, the results suggest that it is a potential candidate as a biomarker for assessing human exposure to and metabolic activation of NPYR.
Collapse
Affiliation(s)
- Ana Paula M Loureiro
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, Brazil
| | | | | | | | | | | | | |
Collapse
|
36
|
Possible participation of oxidative stress in causation of cell proliferation and in vivo mutagenicity in kidneys of gpt delta rats treated with potassium bromate. Toxicology 2009; 257:46-52. [DOI: 10.1016/j.tox.2008.12.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Revised: 12/05/2008] [Accepted: 12/05/2008] [Indexed: 11/22/2022]
|
37
|
Masumura K, Nohmi T. Spontaneous Mutagenesis in Rodents: Spontaneous Gene Mutations Identified by Neutral Reporter Genes in gpt Delta Transgenic Mice and Rats. ACTA ACUST UNITED AC 2009. [DOI: 10.1248/jhs.55.40] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Kenichi Masumura
- Division of Genetics and Mutagenesis, National Institute of Health Sciences
| | - Takehiko Nohmi
- Division of Genetics and Mutagenesis, National Institute of Health Sciences
| |
Collapse
|
38
|
Masumura K. Spontaneous and Induced gpt and Spi− Mutant Frequencies in gpt delta Transgenic Rodents. Genes Environ 2009. [DOI: 10.3123/jemsge.31.105] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|
39
|
Upadhyaya P, Hecht SS. Identification of adducts formed in the reactions of 5'-acetoxy-N'-nitrosonornicotine with deoxyadenosine, thymidine, and DNA. Chem Res Toxicol 2008; 21:2164-71. [PMID: 18821782 PMCID: PMC2646895 DOI: 10.1021/tx8002559] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
N'-Nitrosonornicotine (NNN) is the most prevalent of the carcinogenic tobacco-specific nitrosamines found in all tobacco products. Previous studies have demonstrated that cytochrome P450-mediated 5'-hydroxylation of NNN is a major metabolic pathway leading to mutagenic products, but to date, DNA adducts formed by this pathway have been only partially characterized, and there have been no studies reported on adducts formed with bases other than dGuo. Because adducts with dAdo and dThd have been identified in the DNA of the livers of rats treated with the structurally related carcinogen N-nitrosopyrrolidine, we investigated dAdo and dThd adduct formation from 5'-acetoxyNNN (3), a stable precursor to 5'-hydroxyNNN (2). Reaction of 3 with dAdo gave diastereomeric products, which were identified by their spectral properties and LC-ESI-MS/MS-SRM analysis as N(6)-[5-(3-pyridyl)tetrahydrofuran-2-yl]dAdo (9). This adduct was further characterized by NaBH(3)CN reduction to N(6)-[4-hydroxy-4-(3-pyridyl)but-1-yl]dAdo (17). A second dAdo adduct was identified, after NaBH(3)CN treatment, as 6-[2-(3-pyridyl)pyrrolidin-1-yl]purine-2'-deoxyriboside (18). Reaction of 3 with dThd, followed by NaBH(3)CN reduction, gave O(2)-[4-(3-pyridyl)-4-hydroxybut-1-yl]thymidine (11). Adducts 9, 11, 17, and 18 were all identified by LC-ESI-MS/MS-SRM comparison to synthetic standards. The reaction of 3 with calf thymus DNA was then investigated. The DNA was enzymatically hydrolyzed to deoxyribonucleosides, and the resulting mixture was treated with NaBH(3)CN and analyzed by LC-ESI-MS/MS-SRM. Adducts 11, 17, and 18, as well as the previously identified dGuo adducts, were identified. The results of this study provide a more comprehensive picture of DNA adduct formation by the quantitatively important 5'-hydroxylation pathway of NNN and will facilitate investigation of the presence of these adducts in laboratory animals treated with NNN or in people who use tobacco products.
Collapse
Affiliation(s)
- Pramod Upadhyaya
- Masonic Cancer Center, University of Minnesota Minneapolis, MN 55455
| | - Stephen S. Hecht
- Masonic Cancer Center, University of Minnesota Minneapolis, MN 55455
| |
Collapse
|
40
|
Bomhard EM, Herbold BA. Genotoxic Activities of Aniline and its Metabolites and Their Relationship to the Carcinogenicity of Aniline in the Spleen of Rats. Crit Rev Toxicol 2008; 35:783-835. [PMID: 16468500 DOI: 10.1080/10408440500442384] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Aniline (in the form of its hydrochloride) has been shown to induce a rather rare spectrum of tumors in the spleen of Fischer 344 rats. The dose levels necessary for this carcinogenic activity were in a range where also massive effects on the blood and non-neoplastic splenotoxicity as a consequence of methemoglobinemia were to be observed. This review aimed at clarifying if aniline itself or one of its metabolites has a genotoxic potential which would explain the occurrence of the spleen tumors in rats as a result of a primary genetic activity. The database for aniline and its metabolites is extremely heterogeneous. With validated assays it ranges from a few limited Ames tests (o- and m-hydroxyacetanilide, phenylhydroxylamine, nitrosobenzene) to a broad range of studies covering all genetic endpoints partly with several studies of the same or different test systems (aniline, p-aminophenol, p-hydroxyacetanilide). This makes a direct comparison rather difficult. In addition, a varying number of results with as yet not validated systems are available for aniline and its metabolites. Most results, especially those with validated and well performed/documented studies, did not indicate a potential of aniline to induce gene mutations. In five different mouse lymphoma tests, where colony sizing was performed only in one test, aniline was positive. If this indicates a peculiar feature of a point mutagenic potential or does represent a part of the clastogenic activity for which there is evidence in vitro as well as in vivo remains to be investigated. There is little evidence for a DNA damaging potential of aniline. The clastogenic activity in vivo is confined to dose levels, which are close to lethality essentially due to hematotoxic effects. The quantitatively most important metabolites for experimental animals as well as for humans (p-aminophenol, p-hydroxyacetanilide) seem to have a potential for inducing chromosomal damage in vitro and, at relatively high dose levels, also in vivo. This could be the explanation for the clastogenic effects that have been observed after high doses/concentrations with aniline. They do not induce gene mutations and there is little evidence for a DNA damaging potential. None of these metabolites revealed a splenotoxic potential comparable to that of aniline in studies with repeated or long-term administration to rats. The genotoxicity database on those metabolites with a demonstrated and marked splenotoxic potential, i.e. phenylhydroxylamine, nitrosobenzene, is unfortunately very limited and does not allow to exclude with certainty primary genotoxic events in the development of spleen tumors. But quite a number of considerations by analogy from other investigations support the conclusion that the effects in the spleen do not develop on a primary genotoxic basis. The weight of evidences suggests that the carcinogenic effects in the spleen of rats are the endstage of a chronic high-dose damage of the blood leading to a massive overload of the spleen with iron, which causes chronic oxidative stress. This conclusion, based essentially on pathomorphological observations, and analogy considerations thereof by previous authors, is herewith reconfirmed under consideration of the more recently reported studies on the genotoxicity of aniline and its metabolites, on biochemical measurements indicating oxidative stress, and on the metabolism of aniline. It is concluded that there is no relationship between the damage to the chromosomes at high, toxic doses of aniline and its major metabolites p-aminophenol/p-hydroxyacetanilide and the aniline-induced spleen tumors in the rat.
Collapse
Affiliation(s)
- Ernst M Bomhard
- Institute of Toxicology, Bayer Healthcare AG, D-42096 Wuppertal, Germany.
| | | |
Collapse
|
41
|
Evaluation of the ability of a battery of three in vitro genotoxicity tests to discriminate rodent carcinogens and non-carcinogens. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2008; 654:114-32. [DOI: 10.1016/j.mrgentox.2008.05.002] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2008] [Revised: 05/03/2008] [Accepted: 05/09/2008] [Indexed: 11/24/2022]
|
42
|
Nishikawa A, Umemura T, Ishii Y, Tasaki M, Okamura T, Inoue T, Masumura K, Nohmi T. In vivo Approaches to Study Mechanism of Action of Genotoxic Carcinogens. Genes Environ 2008. [DOI: 10.3123/jemsge.30.120] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|
43
|
Umemura T, Kuroiwa Y, Tasaki M, Okamura T, Ishii Y, Kodama Y, Nohmi T, Mitsumori K, Nishikawa A, Hirose M. Detection of oxidative DNA damage, cell proliferation and in vivo mutagenicity induced by dicyclanil, a non-genotoxic carcinogen, using gpt delta mice. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2007; 633:46-54. [PMID: 17581771 DOI: 10.1016/j.mrgentox.2007.05.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2007] [Revised: 05/09/2007] [Accepted: 05/10/2007] [Indexed: 02/03/2023]
Abstract
To ascertain whether measurement of possible contributing factors to carcinogenesis concurrently with the transgenic mutation assay is useful to understand the mode of action underlying tumorigenesis of non-genotoxic carcinogens, male and female gpt delta mice were given dicyclanil (DC), a mouse hepatocarcinogen showing all negative results in various genotoxicity tests, at a carcinogenic dose for 13 weeks. Together with gpt and Spi(-) mutations, thiobarbituric acid-reactive substances (TBARS), 8-hydroxydeoxyguanosine (8-OHdG) and bromodeoxyuridine labeling indices (BrdU-LIs) in the livers were examined. Whereas there were no changes in TBARS levels among the groups, significant increases in 8-OHdG levels and centrilobular hepatocyte hypertrophy were observed in the treated mice of both genders. In contrast, BrdU-LIs and liver weights for the treated females, but not the males were significantly higher than those for the controls. Likewise, the gpt mutant frequencies (MFs) in the treated females were significantly elevated, GC:TA transversion mutations being predominant. No significant alterations were found in the gpt MFs of the males and the Spi(-) MFs of both sexes. The results for the transgenic mutation assays were consistent with DC carcinogenicity in terms of the sex specificity for females. Considering that 8-OHdG induces GC:TA transversion mutations by mispairing with A bases, it is likely that cells with high proliferation rates and a large amounts of 8-OHdG come to harbor mutations at high incidence. This is the first report demonstrating DC-induced genotoxicity, the results implying that examination of carcinogenic parameters concomitantly with reporter gene mutation assays is able to provide crucial information to comprehend the underlying mechanisms of so-called non-genotoxic carcinogenicity.
Collapse
Affiliation(s)
- Takashi Umemura
- Divisions of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Wang M, Lao Y, Cheng G, Shi Y, Villalta PW, Hecht SS. Identification of adducts formed in the reaction of alpha-acetoxy-N-nitrosopyrrolidine with deoxyribonucleosides and DNA. Chem Res Toxicol 2007; 20:625-33. [PMID: 17394360 PMCID: PMC2518840 DOI: 10.1021/tx600332p] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
N-Nitrosopyrrolidine (NPYR) is a well-established hepatocarcinogen in the rat. NPYR requires metabolic activation by cytochrome P450-catalyzed alpha-hydroxylation to express its carcinogenic activity. This produces alpha-hydroxyNPYR (2), which spontaneously ring opens to 4-oxobutanediazohydroxide (4), a highly reactive intermediate, which may itself modify DNA or yield a cascade of electrophiles that react with DNA to produce adducts. Multiple dGuo adducts formed in this reaction have been previously characterized, but there are no examples of adducts formed with other DNA nucleobases. In this study, we used alpha-acetoxyNPYR (3) as a stable precursor to 2 and 4. Compound 3 was allowed to react with DNA. The DNA was enzymatically hydrolyzed to deoxyribonucleosides, and the products were analyzed by LC-ESI-MS and LC-ESI-MS/MS. Reactions of 3 with individual deoxyribonucleosides were also carried out. The products were identified by their MS, UV, and NMR spectra as N6-(tetrahydrofuran-2-yl)dAdo (16) and N4-(tetrahydrofuran-2-yl)dCyd (17) in addition to the previously characterized N2-(tetrahydrofuran-2-yl)dGuo (13). Unstable dThd adducts were also formed. Further characterization of the adducts was achieved by NaBH3CN reduction of the reaction mixtures of 3 with deoxyribonucleosides or DNA. This produced N6-(4-hydroxybut-1-yl)dAdo (21), N4-(4-hydroxybut-1-yl)dCyd (22), O2-(4-hydroxybut-1-yl)dThd (23), O4-(4-hydroxybut-1-yl)dThd (24), and 3-(4-hydroxybut-1-yl)dThd (25). Adducts 21 and 22 were characterized by their spectral properties, while the dThd adducts 23-25 were identified by comparison to synthetic standards. The results of this study demonstrate that 3 forms adducts with dAdo, dCyd, and dThd in DNA, in addition to the previously characterized dGuo adducts. These newly characterized standards can be used to investigate DNA adduct formation in rats treated with NPYR.
Collapse
Affiliation(s)
- Mingyao Wang
- The Cancer Center, University of Minnesota, Mayo Mail Code 806, 420 Delaware Street SE, Minneapolis, MN 55455
| | - Yanbin Lao
- The Cancer Center, University of Minnesota, Mayo Mail Code 806, 420 Delaware Street SE, Minneapolis, MN 55455
| | - Guang Cheng
- The Cancer Center, University of Minnesota, Mayo Mail Code 806, 420 Delaware Street SE, Minneapolis, MN 55455
| | - Yongli Shi
- The Cancer Center, University of Minnesota, Mayo Mail Code 806, 420 Delaware Street SE, Minneapolis, MN 55455
| | - Peter W. Villalta
- The Cancer Center, University of Minnesota, Mayo Mail Code 806, 420 Delaware Street SE, Minneapolis, MN 55455
| | - Stephen S. Hecht
- The Cancer Center, University of Minnesota, Mayo Mail Code 806, 420 Delaware Street SE, Minneapolis, MN 55455
| |
Collapse
|
45
|
Wang M, Lao Y, Cheng G, Shi Y, Villalta PW, Nishikawa A, Hecht SS. Analysis of adducts in hepatic DNA of rats treated with N-nitrosopyrrolidine. Chem Res Toxicol 2007; 20:634-40. [PMID: 17394361 PMCID: PMC2518975 DOI: 10.1021/tx600333e] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
N-Nitrosopyrrolidine (NPYR) is a hepatocarcinogen in rats. It is metabolically activated by cytochrome P450 enzymes in the liver leading to the formation of 4-oxobutanediazohydroxide (4) and related intermediates that react with DNA to form adducts. Because DNA adducts are thought to be critical in carcinogenesis by NPYR, we analyzed hepatic DNA of NPYR-treated rats for several adducts: N2-(tetrahydrofuran-1-yl)dGuo (N2-THF-dGuo, 13), N6-THF-dAdo (14), N4-THF-dCyd (17), and dThd adducts 15 and 16. The rats were treated with NPYR in the drinking water, 600 ppm for 1 week, or 200 ppm for 4 or 13 weeks. Hepatic DNA was isolated, enzymatically hydrolyzed, and analyzed by capillary LC-ESI-MS-SIM, which indicated the presence of adducts 13, 14, and 17. Because these adducts can be unstable at the deoxyribonucleoside level, further analyses were carried out using DNA treated with NaBH3CN, which converts adducts 13-17 to N2-(4-hydroxybut-1-yl)dGuo [N2-(4-HOB)dGuo, 18], N6-(4-HOB)dAdo (19), O2-(4-HOB)dThd (20), O4-(4-HOB)dThd (21), and N4-(4-HOB)dCyd (22). [15N]-Labeled analogues of adducts 18-20 and 22 were synthesized and used in this analysis, which was performed by capillary LC-ESI-MS/MS-SRM. Convincing evidence for the presence of adducts 18-22 was obtained. Levels of 18, 19, 20, and 21 were (mumol/mol dGuo): 3.41-5.39, 0.02-0.04, 2.56-3.87, and 2.28-5.05, respectively. Compound 22 was not quantified due to interfering peaks. These results provide the first evidence for tetrahydrofuranyl-substituted DNA adducts in the livers of rats treated with NPYR. The finding of dAdo and dThd adducts is of particular interest since previous studies have shown that NPYR causes mutations at AT base pairs in DNA of rat liver.
Collapse
Affiliation(s)
- Mingyao Wang
- The Cancer Center, University of Minnesota, Mayo Mail Code 806, 420 Delaware Street SE, Minneapolis, MN 55455
| | - Yanbin Lao
- The Cancer Center, University of Minnesota, Mayo Mail Code 806, 420 Delaware Street SE, Minneapolis, MN 55455
| | - Guang Cheng
- The Cancer Center, University of Minnesota, Mayo Mail Code 806, 420 Delaware Street SE, Minneapolis, MN 55455
| | - Yongli Shi
- The Cancer Center, University of Minnesota, Mayo Mail Code 806, 420 Delaware Street SE, Minneapolis, MN 55455
| | - Peter W. Villalta
- The Cancer Center, University of Minnesota, Mayo Mail Code 806, 420 Delaware Street SE, Minneapolis, MN 55455
| | - Akiyoshi Nishikawa
- Division of Pathology, National Institute of Health Sciences, Tokyo 158-8501, Japan
| | - Stephen S. Hecht
- The Cancer Center, University of Minnesota, Mayo Mail Code 806, 420 Delaware Street SE, Minneapolis, MN 55455
| |
Collapse
|
46
|
Umemura T, Kanki K, Kuroiwa Y, Ishii Y, Okano K, Nohmi T, Nishikawa A, Hirose M. In vivo mutagenicity and initiation following oxidative DNA lesion in the kidneys of rats given potassium bromate. Cancer Sci 2006; 97:829-35. [PMID: 16805826 PMCID: PMC11158994 DOI: 10.1111/j.1349-7006.2006.00248.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
To clarify the role of 8-OHdG formation as a starting point for carcinogenesis, we examined the dose-dependence and time-course of changes of OGG1 mRNA expression, 8-OHdG levels and in vivo mutations in the kidneys of gpt delta rats given KBrO3 in their drinking water for 13 weeks. There were no remarkable changes in OGG1 mRNA in spite of some increments being statistically significant. Increases of 8-OHdG occurred after 1 week at 500 p.p.m. and after 13 weeks at 250 p.p.m. Elevation of Spi- mutant frequency, suggestive of deletion mutations, occurred after 9 weeks at 500 p.p.m. In a two-stage experiment, F344 rats were given KBrO3 for 13 weeks then, after a 2-week recovery, treated with 1% NTA in the diet for 39 weeks. The incidence and multiplicity of renal preneoplastic lesions in rats given KBrO3 at 500 p.p.m. followed by NTA treatment were significantly higher than in rats treated with NTA alone. Results suggest that a certain period of time might be required for 8-OHdG to cause permanent mutations. The two-step experiment shows that cells exposed to the alteration of the intranuclear status by oxidative stress including 8-OHdG formation might be able to form tumors with appropriate promotion.
Collapse
Affiliation(s)
- Takashi Umemura
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Tokyo 158-8501, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
47
|
Kuroiwa Y, Umemura T, Nishikawa A, Kanki K, Ishii Y, Kodama Y, Masumura KI, Nohmi T, Hirose M. Lack of in vivo mutagenicity and oxidative DNA damage by flumequine in the livers of gpt delta mice. Arch Toxicol 2006; 81:63-9. [PMID: 16802149 DOI: 10.1007/s00204-006-0126-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2006] [Accepted: 06/01/2006] [Indexed: 11/24/2022]
Abstract
Flumequine (FLU), an anti-bacterial quinolone agent, has been recognized as a non-genotoxic carcinogen for the mouse liver, but recent reports have suggested that some genotoxic mechanism involving oxidative DNA damage may be responsible for its hepatocarcinogenesis. In the present study, we investigated this possibility in the mouse liver using male and female B6C3F1 gpt delta mice fed diet containing 0.4% FLU, a carcinogenic dose, for 13 weeks. Measurements of 8-hydroxydeoxyguanosine levels in liver DNA, and gpt point and deletion mutations revealed no significant increases in any of these parameters in either sex. Histopathologically, centrilobular swelling of hepatocytes with vacuolation was apparent, however, together with significant increase in bromodeoxyuridine-labeling indices in the treated males and females. These results suggest that genotoxicity, including oxidative DNA damage, is not involved in mouse hepatocarcinogenesis by FLU, which might rather solely exert tumor-promoting effects in the liver.
Collapse
Affiliation(s)
- Yuichi Kuroiwa
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Tokyo 158-8501, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Moto M, Umemura T, Okamura M, Muguruma M, Ito T, Jin M, Kashida Y, Mitsumori K. Possible involvement of oxidative stress in dicyclanil-induced hepatocarcinogenesis in mice. Arch Toxicol 2006; 80:694-702. [PMID: 16550380 DOI: 10.1007/s00204-006-0086-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2005] [Accepted: 02/28/2006] [Indexed: 10/24/2022]
Abstract
Our previous study suggested the possibilities that dicyclanil (DC), a nongenotoxic carcinogen, produces oxidative stress in the liver of the two-stage hepatocarcinogenesis model of mice and the stress induced probably causes secondary oxidative DNA damage. However, clear evidences demonstrating the relationship between DC-induced hepatocarcinogenesis, oxidative stress, and oxidative DNA damage have not been obtained. To clarify the relationship, further investigations were performed in the liver of the partially hepatectomized (PH) mice maintained on diet containing 1,500 ppm of DC for 13 and 26 weeks after intraperitoneal injection of dimethylnitrosamine (DMN). Significant increases in mRNA expressions of some metabolism- and oxidative stress-related genes with a formation of gamma-glutamyltranspeptidase (GGT) positive foci were observed in the DMN + DC + PH group by the treatment of DC for 13 and 26 weeks. The levels of 8-hydroxy-deoxyguanosine (8-OHdG) in the liver DNA also significantly increased in mice of the DMN + DC + PH group at weeks 13 and 26 and mice given DC alone for 26 weeks. The in vitro measurement of reactive oxygen species (ROS) generation from the mouse liver microsomes showed a significant increase of ROS production in the presence of DC. These results suggest that DC induces oxidative stress which is probably derived from its metabolic pathway, partly, and support our previous speculation that oxidative stress plays one of the important roles in the DC-induced hepatocarcinogenesis in mice.
Collapse
MESH Headings
- 8-Hydroxy-2'-Deoxyguanosine
- Animals
- Carcinogens/toxicity
- Cell Transformation, Neoplastic/chemically induced
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Cell Transformation, Neoplastic/pathology
- Cytochrome P-450 CYP1A1/metabolism
- DNA Damage/drug effects
- DNA Glycosylases/metabolism
- Deoxyguanosine/analogs & derivatives
- Deoxyguanosine/metabolism
- Juvenile Hormones/toxicity
- Liver/drug effects
- Liver/metabolism
- Liver/pathology
- Liver Neoplasms, Experimental/chemically induced
- Liver Neoplasms, Experimental/genetics
- Liver Neoplasms, Experimental/metabolism
- Liver Neoplasms, Experimental/pathology
- Male
- Mice
- Mice, Inbred ICR
- Oxidative Stress/drug effects
- Oxidoreductases/metabolism
- Precancerous Conditions/chemically induced
- Precancerous Conditions/genetics
- Precancerous Conditions/metabolism
- Precancerous Conditions/pathology
- RNA, Messenger/metabolism
- Reactive Oxygen Species/metabolism
- Superoxide Dismutase/metabolism
- Superoxide Dismutase-1
- Thioredoxin Reductase 1
- Thioredoxin-Disulfide Reductase/metabolism
- Time Factors
- gamma-Glutamyltransferase/metabolism
Collapse
Affiliation(s)
- Mitsuyoshi Moto
- Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, Fuchu-shi 183-8509, Tokyo, Japan.
| | | | | | | | | | | | | | | |
Collapse
|