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Suzuki S, Toyoda T, Kato H, Naiki-Ito A, Yamashita Y, Akagi JI, Cho YM, Ogawa K, Takahashi S. Dimethylarsinic acid may promote prostate carcinogenesis in rats. J Toxicol Pathol 2019; 32:73-77. [PMID: 31092973 PMCID: PMC6511539 DOI: 10.1293/tox.2018-0050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 11/26/2018] [Indexed: 11/22/2022] Open
Abstract
Arsenic is a known human carcinogen, inducing tumors of the lung, urinary bladder, skin, liver and prostate. However, there are no reports of prostate tumors induced by arsenicals in in vivo animal models. In a previous study, we found that HMGB2 expression was a predictive marker for prostate carcinogens in the rat 4-week repeated dose test. In this study, six-week-old male F344 rats were orally treated with a total of six chemicals (2-acetylaminofluorene (2-AAF), p-cresidine, dimethylarsinic acid (DMA), glycidol, N-nitrosodiethylamine and acrylamide) for four weeks. Animals were sacrificed at the end of the study, and HMGB2 and Ki-67 immunohistochemistry was performed. The numbers of HMGB2- and Ki-67- positive cells in all prostate lobes were significantly increased by DMA, one of the arsenicals, compared with the controls. Meanwhile, the number of Ki-67-positive cells in lateral and dorsal prostate lobes was significantly decreased by 2-AAF with the reduction of body weight, but HMGB2 expression was not. The other chemicals did not change HMGB2 and Ki-67 expression. These data indicate that DMA may have an ability to enhance prostate carcinogenesis.
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Affiliation(s)
- Shugo Suzuki
- Department of Experimental Pathology and Tumor Biology,
Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-Cho,
Mizuho-Ku, Nagoya, Aichi 467-8601, Japan
| | - Takeshi Toyoda
- Division of Pathology, National Institute of Health
Sciences, 3-25-26 Tonomachi, Kawasaki, Kanagawa 210-9501, Japan
| | - Hiroyuki Kato
- Department of Experimental Pathology and Tumor Biology,
Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-Cho,
Mizuho-Ku, Nagoya, Aichi 467-8601, Japan
| | - Aya Naiki-Ito
- Department of Experimental Pathology and Tumor Biology,
Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-Cho,
Mizuho-Ku, Nagoya, Aichi 467-8601, Japan
| | - Yoriko Yamashita
- Department of Experimental Pathology and Tumor Biology,
Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-Cho,
Mizuho-Ku, Nagoya, Aichi 467-8601, Japan
| | - Jun-ichi Akagi
- Division of Pathology, National Institute of Health
Sciences, 3-25-26 Tonomachi, Kawasaki, Kanagawa 210-9501, Japan
| | - Young-Man Cho
- Division of Pathology, National Institute of Health
Sciences, 3-25-26 Tonomachi, Kawasaki, Kanagawa 210-9501, Japan
| | - Kumiko Ogawa
- Division of Pathology, National Institute of Health
Sciences, 3-25-26 Tonomachi, Kawasaki, Kanagawa 210-9501, Japan
| | - Satoru Takahashi
- Department of Experimental Pathology and Tumor Biology,
Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-Cho,
Mizuho-Ku, Nagoya, Aichi 467-8601, Japan
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Akagi JI, Cho YM, Mizuta Y, Tatebe C, Sato K, Ogawa K. Subchronic toxicity evaluation of isoeugenyl methyl ether in F344/DuCrj rats by 13-week oral administration. Regul Toxicol Pharmacol 2019; 102:34-39. [DOI: 10.1016/j.yrtph.2018.12.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 11/22/2018] [Accepted: 12/04/2018] [Indexed: 10/27/2022]
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Hirata T, Cho YM, Suzuki I, Toyoda T, Akagi JI, Nakamura Y, Numazawa S, Ogawa K. 4-Methylthio-3-butenyl isothiocyanate (MTBITC) induced apoptotic cell death and G2/M cell cycle arrest via ROS production in human esophageal epithelial cancer cells. J Toxicol Sci 2019; 44:73-81. [DOI: 10.2131/jts.44.73] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Tadashi Hirata
- Division of Pathology, National Institute of Health Sciences
- Division of Toxicology, Department of Pharmacology, Toxicology and Therapeutics, School of Pharmacy, Showa University
| | - Young-Man Cho
- Division of Pathology, National Institute of Health Sciences
| | - Isamu Suzuki
- Division of Pathology, National Institute of Health Sciences
- Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University
| | - Takeshi Toyoda
- Division of Pathology, National Institute of Health Sciences
| | - Jun-ichi Akagi
- Division of Pathology, National Institute of Health Sciences
| | - Yasushi Nakamura
- Kyoto Institute of Japanese Diet Culture, Kyoto Prefectural University
| | - Satoshi Numazawa
- Division of Toxicology, Department of Pharmacology, Toxicology and Therapeutics, School of Pharmacy, Showa University
| | - Kumiko Ogawa
- Division of Pathology, National Institute of Health Sciences
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Akagi JI, Cho YM, Mizuta Y, Toyoda T, Ogawa K. Subchronic toxicity evaluation of 5-hexenyl isothiocyanate, a nature identical flavoring substance from Wasabia japonica, in F344/DuCrj rats. Food Chem Toxicol 2018; 122:80-86. [DOI: 10.1016/j.fct.2018.09.060] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 09/20/2018] [Accepted: 09/24/2018] [Indexed: 12/14/2022]
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Toyoda T, Cho YM, Akagi JI, Mizuta Y, Matsushita K, Nishikawa A, Imaida K, Ogawa K. A 13-week subchronic toxicity study of acetaminophen using an obese rat model. J Toxicol Sci 2018; 43:423-433. [DOI: 10.2131/jts.43.423] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Takeshi Toyoda
- Division of Pathology, National Institute of Health Sciences
| | - Young-Man Cho
- Division of Pathology, National Institute of Health Sciences
| | - Jun-ichi Akagi
- Division of Pathology, National Institute of Health Sciences
| | - Yasuko Mizuta
- Division of Pathology, National Institute of Health Sciences
| | | | - Akiyoshi Nishikawa
- Biological Safety Research Center, National Institute of Health Sciences
| | - Katsumi Imaida
- Onco-Pathology, Department of Pathology and Host-Defense, Kagawa University
| | - Kumiko Ogawa
- Division of Pathology, National Institute of Health Sciences
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Akagi J, Yokoi M, Cho YM, Toyoda T, Ohmori H, Hanaoka F, Ogawa K. Hypersensitivity of mouse embryonic fibroblast cells defective for DNA polymerases η, ι and κ to various genotoxic compounds: Its potential for application in chemical genotoxic screening. DNA Repair (Amst) 2017; 61:76-85. [PMID: 29247828 DOI: 10.1016/j.dnarep.2017.11.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 10/19/2017] [Accepted: 11/23/2017] [Indexed: 12/11/2022]
Abstract
Genotoxic agents cause modifications of genomic DNA, such as alkylation, oxidation, bulky adduct formation, and strand breaks, which potentially induce mutations and changes to the structure or number of genes. Majority of point mutations are generated during error-prone bypass of modified nucleotides (translesion DNA synthesis, TLS); however, when TLS fails, replication forks stalled at lesions eventually result in more lethal effects, formation of double-stranded breaks (DSBs). Here we compared sensitivities to various compounds among mouse embryonic fibroblasts derived from wild-type and knock-out mice lacking one of the three Y-family TLS DNA polymerases (Polη, Polι, and Polκ) or all of them (TKO). The compounds tested in this study include genotoxins such as methyl methanesulfonate (MMS) and nongenotoxins such as ammonium chloride. We found that TKO cells exhibited the highest sensitivities to most of the tested genotoxins, but not to the non-genotoxins. In order to quantitatively evaluate the hypersensitivity of TKO cells to different chemicals, we calculated ratios of half-maximal inhibitory concentration for WT and TKO cells. The ratios for 9 out of 10 genotoxins ranged from 2.29 to 5.73, while those for 5 nongenotoxins ranged from 0.81 to 1.63. Additionally, the two markers for DNA damage, ubiquitylated proliferating cell nuclear antigen and γ-H2AX after MMS treatment, were accumulated in TKO cells more greatly than in WT cells. Furthermore, following MMS treatment, TKO cells exhibited increased frequency of sister chromatid exchange compared with WT cells. These results indicated that the hypersensitivity of TKO cells to genotoxins resulted from replication fork stalling and subsequent DNA double-strand breaks, thus demonstrating that TKO cells should be useful for evaluating chemical genotoxicity.
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Affiliation(s)
- Junichi Akagi
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
| | - Masayuki Yokoi
- Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan; Biosignal Research Center, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo Prefecture 657-8501, Japan
| | - Young-Man Cho
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
| | - Takeshi Toyoda
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
| | - Haruo Ohmori
- Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan
| | - Fumio Hanaoka
- Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan; Life Science Center of Tsukuba Advanced Research Alliance, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki Prefecture 305-8577, Japan
| | - Kumiko Ogawa
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
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Toyoda T, Cho YM, Akagi JI, Mizuta Y, Matsushita K, Nishikawa A, Imaida K, Ogawa K. Altered susceptibility of an obese rat model to 13-week subchronic toxicity induced by 3-monochloropropane-1,2-diol. J Toxicol Sci 2017; 42:1-11. [DOI: 10.2131/jts.42.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Takeshi Toyoda
- Division of Pathology, National Institute of Health Sciences
| | - Young-Man Cho
- Division of Pathology, National Institute of Health Sciences
| | - Jun-ichi Akagi
- Division of Pathology, National Institute of Health Sciences
| | - Yasuko Mizuta
- Division of Pathology, National Institute of Health Sciences
| | | | - Akiyoshi Nishikawa
- Biological Safety Research Center, National Institute of Health Sciences
| | - Katsumi Imaida
- Onco-Pathology, Department of Pathology and Host-Defense, Kagawa University
| | - Kumiko Ogawa
- Division of Pathology, National Institute of Health Sciences
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Suzuki I, Cho YM, Hirata T, Toyoda T, Akagi JI, Nakamura Y, Sasaki A, Nakamura T, Okamoto S, Shirota K, Suetome N, Nishikawa A, Ogawa K. Toxic effects of 4-methylthio-3-butenyl isothiocyanate (Raphasatin) in the rat urinary bladder without genotoxicity. J Appl Toxicol 2016; 37:485-494. [DOI: 10.1002/jat.3384] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 08/01/2016] [Accepted: 08/02/2016] [Indexed: 01/16/2023]
Affiliation(s)
- Isamu Suzuki
- Division of Pathology; National Institute of Health Sciences; Tokyo 158-8501 Japan
- Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences; Gifu University; Gifu 501-1193 Japan
| | - Young-Man Cho
- Division of Pathology; National Institute of Health Sciences; Tokyo 158-8501 Japan
| | - Tadashi Hirata
- Division of Pathology; National Institute of Health Sciences; Tokyo 158-8501 Japan
- Department of Pharmacology, School of Pharmacy; Showa University; Tokyo 142-8555 Japan
| | - Takeshi Toyoda
- Division of Pathology; National Institute of Health Sciences; Tokyo 158-8501 Japan
| | - Jun-ichi Akagi
- Division of Pathology; National Institute of Health Sciences; Tokyo 158-8501 Japan
| | - Yasushi Nakamura
- Faculty of Life and Environmental Sciences; Kyoto Prefectural University; Kyoto 606-8522 Japan
- Kyoto Prefectural Agriculture; Forestry & Fisheries Technology Center; Kyoto 621-0806 Japan
| | - Azusa Sasaki
- Faculty of Life and Environmental Sciences; Kyoto Prefectural University; Kyoto 606-8522 Japan
| | - Takako Nakamura
- Faculty of Life and Environmental Sciences; Kyoto Prefectural University; Kyoto 606-8522 Japan
| | - Shigehisa Okamoto
- Department of Food Science and Biotechnology; Kagoshima University; Kagoshima Kagoshima 890-0065 Japan
| | - Koji Shirota
- Kyoto Prefectural Agriculture; Forestry & Fisheries Technology Center; Kyoto 621-0806 Japan
| | - Noboru Suetome
- Kyoto Prefectural Agriculture; Forestry & Fisheries Technology Center; Kyoto 621-0806 Japan
| | - Akiyoshi Nishikawa
- Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences; Gifu University; Gifu 501-1193 Japan
- Biological Safety Research Center; National Institute of Health Sciences; Tokyo 158-8501 Japan
| | - Kumiko Ogawa
- Division of Pathology; National Institute of Health Sciences; Tokyo 158-8501 Japan
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Onami S, Cho YM, Toyoda T, Akagi JI, Fujiwara S, Ochiai R, Tsujino K, Nishikawa A, Ogawa K. Orally administered glycidol and its fatty acid esters as well as 3-MCPD fatty acid esters are metabolized to 3-MCPD in the F344 rat. Regul Toxicol Pharmacol 2015; 73:726-31. [PMID: 26520183 DOI: 10.1016/j.yrtph.2015.10.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Revised: 10/21/2015] [Accepted: 10/22/2015] [Indexed: 10/22/2022]
Abstract
IARC has classified glycidol and 3-monochloropropane-1,2-diol (3-MCPD) as group 2A and 2B, respectively. Their esters are generated in foodstuffs during processing and there are concerns that they may be hydrolyzed to the carcinogenic forms in vivo. Thus, we conducted two studies. In the first, we administered glycidol and 3-MCPD and associated esters (glycidol oleate: GO, glycidol linoleate: GL, 3-MCPD dipalmitate: CDP, 3-MCPD monopalmitate: CMP, 3-MCPD dioleate: CDO) to male F344 rats by single oral gavage. After 30 min, 3-MCPD was detected in serum from all groups. Glycidol was detected in serum from the rats given glycidol or GL and CDP and CDO in serum from rats given these compounds. In the second, we examined if metabolism occurs on simple reaction with rat intestinal contents (gastric, duodenal and cecal contents) from male F344 gpt delta rats. Newly produced 3-MCPD was detected in all gut contents incubated with the three 3-MCPD fatty acid esters and in gastric and duodenal contents incubated with glycidol and in duodenal and cecal contents incubated with GO. Although our observation was performed at 1 time point, the results showed that not only 3-MCPD esters but also glycidol and glycidol esters are metabolized into 3-MCPD in the rat.
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Affiliation(s)
- Saeko Onami
- Division of Pathology, National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya-ku, Tokyo, 158-8501, Japan; Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1, Yanagido, Gifu, 501-1193, Japan
| | - Young-Man Cho
- Division of Pathology, National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya-ku, Tokyo, 158-8501, Japan
| | - Takeshi Toyoda
- Division of Pathology, National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya-ku, Tokyo, 158-8501, Japan
| | - Jun-ichi Akagi
- Division of Pathology, National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya-ku, Tokyo, 158-8501, Japan
| | - Satoshi Fujiwara
- Division of Pharmaceutical and Life Sciences, Shimadzu Techno-Research Inc., 1, Nishinokyo-Shimoaicho, Nakagyo-ku, Kyoto, 604-8436, Japan
| | - Ryosuke Ochiai
- Division of Pharmaceutical and Life Sciences, Shimadzu Techno-Research Inc., 1, Nishinokyo-Shimoaicho, Nakagyo-ku, Kyoto, 604-8436, Japan
| | - Kazushige Tsujino
- Division of Pharmaceutical and Life Sciences, Shimadzu Techno-Research Inc., 1, Nishinokyo-Shimoaicho, Nakagyo-ku, Kyoto, 604-8436, Japan
| | - Akiyoshi Nishikawa
- Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1, Yanagido, Gifu, 501-1193, Japan; Biological Safety Research Center, National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya-ku, Tokyo, 158-8501, Japan
| | - Kumiko Ogawa
- Division of Pathology, National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya-ku, Tokyo, 158-8501, Japan.
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Toyoda T, Cho YM, Akagi JI, Mizuta Y, Ogawa K. Abstract 4580: Expression of γH2AX as a biomarker of genotoxic carcinogen in the urinary bladder of rats. Carcinogenesis 2015. [DOI: 10.1158/1538-7445.am2015-4580] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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
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Toyoda T, Cho YM, Mizuta Y, Akagi JI, Ogawa K. A 13-week subchronic toxicity study of ferric citrate in F344 rats. Food Chem Toxicol 2014; 74:68-75. [DOI: 10.1016/j.fct.2014.09.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 09/08/2014] [Accepted: 09/10/2014] [Indexed: 01/11/2023]
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Toyoda T, Cho YM, Mizuta Y, Akagi JI, Nishikawa A, Ogawa K. A 13-week subchronic toxicity study of sodium iron chlorophyllin in F344 rats. J Toxicol Sci 2014; 39:109-19. [PMID: 24418715 DOI: 10.2131/jts.39.109] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Sodium iron chlorophyllin (SIC), a water-soluble chlorophyll derivative, has been used as a food additive for green coloration. In the present study, a subchronic toxicity study of SIC was performed in male and female F344 rats with oral administration in diet at concentrations of 0%, 0.2%, 1.0%, and 5.0% for 13 weeks. No mortalities, abnormal clinical signs, and hematological changes were observed in any of the groups during the experiment. Significant reduction of body weight gain was noted in 5.0% males. In serum biochemistry, serum transferrin levels were significantly increased in 5.0% males and females. Relative spleen weights of both sexes were markedly reduced with 5.0% SIC as compared to the controls, and absolute weights of spleen were also significantly decreased in males. On histopathological assessment, diffuse hypertrophy of acinar cells in the parotid gland was observed in all examined 5.0% males and females, but not in the other groups. Based on the histopathology of the parotid glands, the no-observed-adverse-effect level (NOAEL) of SIC in the present study was estimated to be 1.0% (609 mg/kg bw/day for males and 678 mg/kg bw/day for females).
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Affiliation(s)
- Takeshi Toyoda
- Division of Pathology, National Institute of Health Sciences
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Hashimoto K, Cho Y, Yang IY, Akagi JI, Ohashi E, Tateishi S, de Wind N, Hanaoka F, Ohmori H, Moriya M. The vital role of polymerase ζ and REV1 in mutagenic, but not correct, DNA synthesis across benzo[a]pyrene-dG and recruitment of polymerase ζ by REV1 to replication-stalled site. J Biol Chem 2012; 287:9613-22. [PMID: 22303021 DOI: 10.1074/jbc.m111.331728] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The DNA synthesis across DNA lesions, termed translesion synthesis (TLS), is a complex process influenced by various factors. To investigate this process in mammalian cells, we examined TLS across a benzo[a]pyrene dihydrodiol epoxide-derived dG adduct (BPDE-dG) using a plasmid bearing a single BPDE-dG and genetically engineered mouse embryonic fibroblasts (MEFs). In wild-type MEFs, TLS was extremely miscoding (>90%) with G → T transversions being predominant. Knockout of the Rev1 gene decreased both the TLS efficiency and the miscoding frequency. Knockout of the Rev3L gene, coding for the catalytic subunit of pol ζ, caused even greater decreases in these two TLS parameters; almost all residual TLS were error-free. Thus, REV1 and pol ζ are critical to mutagenic, but not accurate, TLS across BPDE-dG. The introduction of human REV1 cDNA into Rev1(-/-) MEFs restored the mutagenic TLS, but a REV1 mutant lacking the C terminus did not. Yeast and mammalian three-hybrid assays revealed that the REV7 subunit of pol ζ mediated the interaction between REV3 and the REV1 C terminus. These results support the hypothesis that REV1 recruits pol ζ through the interaction with REV7. Our results also predict the existence of a minor REV1-independent pol ζ recruitment pathway. Finally, although mutagenic TLS across BPDE-dG largely depends on RAD18, experiments using Polk(-/-) Polh(-/-) Poli(-/-) triple-gene knockout MEFs unexpectedly revealed that another polymerase(s) could insert a nucleotide opposite BPDE-dG. This indicates that a non-Y family polymerase(s) can insert a nucleotide opposite BPDE-dG, but the subsequent extension from miscoding termini depends on REV1-polζ in a RAD18-dependent manner.
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Affiliation(s)
- Keiji Hashimoto
- Department of Pharmacological Sciences, State University of New York, Stony Brook, New York 11794-8651, USA
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Ito W, Yokoi M, Sakayoshi N, Sakurai Y, Akagi JI, Mitani H, Hanaoka F. Stalled Polη at its cognate substrate initiates an alternative translesion synthesis pathway via interaction with REV1. Genes Cells 2012; 17:98-108. [DOI: 10.1111/j.1365-2443.2011.01576.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Sugasawa K, Akagi JI, Nishi R, Iwai S, Hanaoka F. Two-step recognition of DNA damage for mammalian nucleotide excision repair: Directional binding of the XPC complex and DNA strand scanning. Mol Cell 2009; 36:642-53. [PMID: 19941824 DOI: 10.1016/j.molcel.2009.09.035] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 08/03/2009] [Accepted: 09/02/2009] [Indexed: 10/20/2022]
Abstract
For mammalian nucleotide excision repair (NER), DNA lesions are recognized in at least two steps involving detection of unpaired bases by the XPC protein complex and the subsequent verification of injured bases. Although lesion verification is important to ensure high damage discrimination and the accuracy of the repair system, it has been unclear how this is accomplished. Here, we show that damage verification involves scanning of a DNA strand from the site where XPC is initially bound. Translocation by the NER machinery exhibits a 5'-to-3' directionality, strongly suggesting involvement of the XPD helicase, a component of TFIIH. Furthermore, the initial orientation of XPC binding is crucial in that only one DNA strand is selected to search for the presence of lesions. Our results dissect the intricate molecular mechanism of NER and provide insights into a strategy for mammalian cells to survey large genomes to detect DNA damage.
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Affiliation(s)
- Kaoru Sugasawa
- Biosignal Research Center, Kobe University, Rokkodai, Nada-ku, Hyogo, Japan.
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Akagi JI, Masutani C, Kataoka Y, Kan T, Ohashi E, Mori T, Ohmori H, Hanaoka F. Interaction with DNA polymerase η is required for nuclear accumulation of REV1 and suppression of spontaneous mutations in human cells. DNA Repair (Amst) 2009; 8:585-99. [DOI: 10.1016/j.dnarep.2008.12.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Revised: 11/27/2008] [Accepted: 12/09/2008] [Indexed: 01/26/2023]
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