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Cao X, Zheng S, Zeng Y, Shi Y, Du J, Huang C, Shen Y, Liu P, Guo X, Gao X. Effects of chronic Cr and Ni co-exposure on liver inflammation and autophagy in mice by regulating the TLR4/mTOR pathway. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 926:171921. [PMID: 38522525 DOI: 10.1016/j.scitotenv.2024.171921] [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: 01/07/2024] [Revised: 02/28/2024] [Accepted: 03/21/2024] [Indexed: 03/26/2024]
Abstract
Exposure to Cr and/or Ni can have widespread implications on the environment and health. However, the specific toxic effects of chronic Cr and Ni co-exposure on mice liver have not been reported. To ascertain the combined toxic effects of chronic Cr and Ni co-exposure on liver damage in mice, 80 6-week-old female C57BL/6 J mice were randomly divided into 4 groups: the Con group, Cr group (Cr+6 50 mg/L), Ni group (Ni+2 110 mg/L), and Cr + Ni group (Cr+6 50 mg/L + Ni+2 110 mg/L). The trial period lasted for 16 weeks. The results showed that Cr+6 and/or Ni+2 increased liver weight and liver index (P < 0.05) in mice, caused histological abnormality and ultrastructural damage, and micronutrients imbalance in mice liver. These findings serve as the basis for subsequent experiments. Compared with the individual exposure group, chronic Cr and Ni co-exposure resulted in decreased levels and activities of ALT, AST, MDA, T-AOC, and T-SOD (P < 0.05) in liver tissue, and decreased the mRNA expression levels of the TLR4/mTOR pathway related factors (TLR4, TRAM, TRIF, TBK-1, IRF-3, MyD88, IRAK-4, TRAF6, TAK-1, IKKβ, NF-κB, IL-1β, IL-6, TNFα, ULK1, Beclin 1, LC3) (P < 0.05) and decreased the protein expression levels of the factors (TLR4, MyD88, TRAF6, NF-κB p50, IL-6, TNFα, ULK1, LC3II/LC3I) (P < 0.05). Moreover, factorial analysis revealed the interaction between Cr and Ni, which was manifested as antagonistic effects on Cr concentration, Ni concentration, and TLR4, MyD88, NF-κB, mTOR, LC3, and p62 mRNA expression levels. In conclusion, the TLR4/mTOR pathway as a mechanism through which chronic Cr and Ni co-exposure induce liver inflammation and autophagy in mice, and there was an antagonistic effect between Cr and Ni. The above results provided a theoretical basis for understanding the underlying processes.
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Affiliation(s)
- Xianhong Cao
- Jiangxi Provincial Key Laboratory for Animal Health, Institute of Animal Population Health, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, Jiangxi, China; Ganzhou Animal Husbandry and Fisheries Research Institute, Gannan Academy of Sciences, Ganzhou, Jiangxi, China
| | - Shuangyan Zheng
- Jiangxi Provincial Key Laboratory for Animal Health, Institute of Animal Population Health, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Yizhou Zeng
- Jiangxi Provincial Key Laboratory for Animal Health, Institute of Animal Population Health, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Yan Shi
- School of Computer and Information Engineering, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Jun Du
- Jiangxi Provincial Key Laboratory for Animal Health, Institute of Animal Population Health, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Cheng Huang
- Jiangxi Provincial Key Laboratory for Animal Health, Institute of Animal Population Health, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Yufan Shen
- Jiangxi Provincial Key Laboratory for Animal Health, Institute of Animal Population Health, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Ping Liu
- Jiangxi Provincial Key Laboratory for Animal Health, Institute of Animal Population Health, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Xiaoquan Guo
- Jiangxi Provincial Key Laboratory for Animal Health, Institute of Animal Population Health, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Xiaona Gao
- Jiangxi Provincial Key Laboratory for Animal Health, Institute of Animal Population Health, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, Jiangxi, China.
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2
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Ozawa S, Ojiro R, Tang Q, Zou X, Woo GH, Yoshida T, Shibutani M. Identification of genes showing altered DNA methylation and gene expression in the renal proximal tubular cells of rats treated with ochratoxin A for 13 weeks. J Appl Toxicol 2023; 43:1533-1548. [PMID: 37162024 DOI: 10.1002/jat.4495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/07/2023] [Accepted: 05/08/2023] [Indexed: 05/11/2023]
Abstract
Ochratoxin A (OTA) is a mycotoxin that causes renal carcinogenicity following the induction of karyomegaly in proximal tubular cells after repeated administration to rats. Here, we performed gene profiling regarding altered DNA methylation and gene expression in the renal tubules focusing on the mechanism of OTA-induced carcinogenesis. For this purpose, OTA or 3-chloro-1,2-propanediol (3-MCPD), a renal carcinogen not inducing karyomegaly, was administered to rats for 13 weeks, and DNA methylation array and RNA sequencing analyses were performed on proximal tubular cells. Genes for which OTA altered the methylation status and gene expression level, after excluding genes showing similar expression changes by 3-MCPD, were subjected to confirmation analysis of the transcript level by real-time reverse-transcription PCR. Gene Ontology (GO)-based functional annotation analysis of validated genes revealed a cluster of hypermethylated and downregulated genes enriched under the GO term "mitochondrion," such as those associated with metabolic reprogramming in carcinogenic process (Clpx, Mrpl54, Mrps34, and Slc25a23). GO terms enriched for hypomethylated and upregulated genes included "response to arsenic-containing substance," represented by Cdkn1a involved in cell cycle arrest, and "positive regulation of IL-17 production," represented by Osm potentiating cell proliferation promotion. Other genes that did not cluster under any GO term included Lrrc14 involved in NF-κB-mediated inflammation, Gen1 linked to DNA repair, Has1 related to chromosomal aberration, and Anxa3 involved in tumor development and progression. In conclusion, a variety of genes engaged in carcinogenic processes were obtained by epigenetic gene profiling in rat renal tubular cells specific to OTA treatment for 13 weeks.
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Affiliation(s)
- Shunsuke Ozawa
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
- Cooperative Division of Veterinary Sciences, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Ryota Ojiro
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
- Cooperative Division of Veterinary Sciences, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Qian Tang
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
- Cooperative Division of Veterinary Sciences, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Xinyu Zou
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
- Cooperative Division of Veterinary Sciences, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Gye-Hyeong Woo
- Laboratory of Histopathology, Department of Clinical Laboratory Science, Semyung University, Jecheon, Republic of Korea
| | - Toshinori Yoshida
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
- Cooperative Division of Veterinary Sciences, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Makoto Shibutani
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
- Cooperative Division of Veterinary Sciences, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Fuchu, Japan
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3
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Hilton GM, Adcock C, Akerman G, Baldassari J, Battalora M, Casey W, Clippinger AJ, Cope R, Goetz A, Hayes AW, Papineni S, Peffer RC, Ramsingh D, Williamson Riffle B, Sanches da Rocha M, Ryan N, Scollon E, Visconti N, Wolf DC, Yan Z, Lowit A. Rethinking chronic toxicity and carcinogenicity assessment for agrochemicals project (ReCAAP): A reporting framework to support a weight of evidence safety assessment without long-term rodent bioassays. Regul Toxicol Pharmacol 2022; 131:105160. [PMID: 35311659 DOI: 10.1016/j.yrtph.2022.105160] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 03/07/2022] [Accepted: 03/14/2022] [Indexed: 11/17/2022]
Abstract
Rodent cancer bioassays have been long-required studies for regulatory assessment of human cancer hazard and risk. These studies use hundreds of animals, are resource intensive, and certain aspects of these studies have limited human relevance. The past 10 years have seen an exponential growth of new technologies with the potential to effectively evaluate human cancer hazard and risk while reducing, refining, or replacing animal use. To streamline and facilitate uptake of new technologies, a workgroup comprised of scientists from government, academia, non-governmental organizations, and industry stakeholders developed a framework for waiver rationales of rodent cancer bioassays for consideration in agrochemical safety assessment. The workgroup used an iterative approach, incorporating regulatory agency feedback, and identifying critical information to be considered in a risk assessment-based weight of evidence determination of the need for rodent cancer bioassays. The reporting framework described herein was developed to support a chronic toxicity and carcinogenicity study waiver rationale, which includes information on use pattern(s), exposure scenario(s), pesticidal mode-of-action, physicochemical properties, metabolism, toxicokinetics, toxicological data including mechanistic data, and chemical read-across from similar registered pesticides. The framework could also be applied to endpoints other than chronic toxicity and carcinogenicity, and for chemicals other than agrochemicals.
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Affiliation(s)
- Gina M Hilton
- PETA Science Consortium International e.V., Stuttgart, Germany.
| | - Catherine Adcock
- Health Canada, Pest Management Regulatory Agency, Ottawa, Ontario, Canada
| | - Gregory Akerman
- United States Environmental Protection Agency, Office of Pesticide Programs, Washington DC, USA
| | | | | | - Warren Casey
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | | | - Rhian Cope
- Australian Pesticides and Veterinary Medicines Authority, Armidale, New South Wales, Australia
| | - Amber Goetz
- Syngenta Crop Protection, LLC, Greensboro, NC, USA
| | - A Wallace Hayes
- University of South Florida College of Public Health, Tampa, FL, USA
| | | | | | - Deborah Ramsingh
- Health Canada, Pest Management Regulatory Agency, Ottawa, Ontario, Canada
| | | | | | - Natalia Ryan
- Syngenta Crop Protection, LLC, Greensboro, NC, USA
| | | | | | | | | | - Anna Lowit
- United States Environmental Protection Agency, Office of Pesticide Programs, Washington DC, USA
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4
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Rooney J, Wehmas LC, Ryan N, Chorley BN, Hester SD, Kenyon EM, Schmid JE, George BJ, Hughes MF, Sey YM, Tennant AH, Simmons JE, Wood CE, Corton JC. Genomic comparisons between hepatocarcinogenic and non-hepatocarcinogenic organophosphate insecticides in the mouse liver. Toxicology 2022; 465:153046. [PMID: 34813904 DOI: 10.1016/j.tox.2021.153046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 11/12/2021] [Accepted: 11/17/2021] [Indexed: 11/27/2022]
Abstract
Short-term biomarkers of toxicity have an increasingly important role in the screening and prioritization of new chemicals. In this study, we examined early indicators of liver toxicity for three reference organophosphate (OP) chemicals, which are among the most widely used insecticides in the world. The OP methidathion was previously shown to increase the incidence of liver toxicity, including hepatocellular tumors, in male mice. To provide insights into the adverse outcome pathway (AOP) that underlies these tumors, effects of methidathion in the male mouse liver were examined after 7 and 28 day exposures and compared to those of two other OPs that either do not increase (fenthion) or possibly suppress liver cancer (parathion) in mice. None of the chemicals caused increases in liver weight/body weight or histopathological changes in the liver. Parathion decreased liver cell proliferation after 7 and 28 days while the other chemicals had no effects. There was no evidence for hepatotoxicity in any of the treatment groups. Full-genome microarray analysis of the livers from the 7 and 28 day treatments demonstrated that methidathion and fenthion regulated a large number of overlapping genes, while parathion regulated a unique set of genes. Examination of cytochrome P450 enzyme activities and use of predictive gene expression biomarkers found no consistent evidence for activation of AhR, CAR, PXR, or PPARα. Parathion suppressed the male-specific gene expression pattern through STAT5b, similar to genetic and dietary conditions that decrease liver tumor incidence in mice. Overall, these findings indicate that methidathion causes liver cancer by a mechanism that does not involve common mechanisms of liver cancer induction.
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Affiliation(s)
- John Rooney
- Oak Ridge Institute for Science and Education (ORISE) Research Participant at US EPA, Office of Research and Development, Center for Computational Toxicology and Exposure (formerly NHEERL), Research Triangle Park, NC, 27711, United States; National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States(3).
| | - Leah C Wehmas
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States.
| | - Natalia Ryan
- Oak Ridge Institute for Science and Education (ORISE) Research Participant at US EPA, Office of Research and Development, Center for Computational Toxicology and Exposure (formerly NHEERL), Research Triangle Park, NC, 27711, United States; National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States(3).
| | - Brian N Chorley
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States.
| | - Susan D Hester
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States.
| | - Elaina M Kenyon
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States.
| | - Judith E Schmid
- National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States(3).
| | - Barbara Jane George
- Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States.
| | - Michael F Hughes
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States.
| | - Yusupha M Sey
- Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States.
| | - Alan H Tennant
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States.
| | - Jane Ellen Simmons
- Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States.
| | - Charles E Wood
- National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States(3).
| | - J Christopher Corton
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States.
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5
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Felter SP, Bhat VS, Botham PA, Bussard DA, Casey W, Hayes AW, Hilton GM, Magurany KA, Sauer UG, Ohanian EV. Assessing chemical carcinogenicity: hazard identification, classification, and risk assessment. Insight from a Toxicology Forum state-of-the-science workshop. Crit Rev Toxicol 2022; 51:653-694. [DOI: 10.1080/10408444.2021.2003295] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
| | | | | | - David A. Bussard
- U.S. Environmental Protection Agency, Office of the Science Advisor, Policy and Engagement, Washington, DC, USA
| | - Warren Casey
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - A. Wallace Hayes
- University of South Florida College of Public Health, Tampa, FL, USA
| | - Gina M. Hilton
- PETA Science Consortium International e.V., Stuttgart, Germany
| | | | | | - Edward V. Ohanian
- United States Environmental Protection Agency, Office of Water, Washington, DC, USA
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6
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Mistry P, McInnes EF, Beevers C, Wolf D, Currie RA, Salimraj R, Parsons P. An evaluation of carcinogenicity predictors from short-term and sub chronic repeat-dose studies of agrochemicals in rats: Opportunities to refine and reduce animal use. Toxicol Lett 2021; 351:18-27. [PMID: 34364947 DOI: 10.1016/j.toxlet.2021.08.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 07/15/2021] [Accepted: 08/03/2021] [Indexed: 10/20/2022]
Abstract
The aim of this study was to examine whether short term, repeat dose, rat studies provide sufficient information about potential carcinogenicity to enable predictions about the carcinogenic potential of agrochemicals to be made earlier in compound development. This study aimed to identify any correlations between toxicity findings obtained for short term rat studies (28 day and 90 day) and neoplastic findings obtained from 24 month rat carcinogenicity studies for agrochemical compounds (18 compounds) tested in Han Wistar and Sprague Dawley rats. The macroscopic pathology, microscopic pathology, hematology, biochemistry, organ weights, estrogen receptor activation and genotoxicity results were examined. Seven out of 18 non genotoxic compounds developed tumors in treated rats in the carcinogenicity study and of these, two compounds showed no preneoplastic findings in the affected tissues (false positives). Of the remaining five true positives, correlations were noted between corneal opacity and keratitis (90 day study) as early indicators of squamous cell carcinoma and papilloma of the cornea of the eye (compound 1, a hydroxyphenylpyruvate dioxygenase inhibitor) and inflammation of the stomach and kidney (90 day study) and gastric squamous cell papilloma and squamous cell carcinoma and renal tubular adenoma and carcinoma, respectively (compound 12, a fungicide with multisite activity). Minor decreases in uterine weight and increases in estradiol hydroxylation activity at 28 days were associated with endometrial adenocarcinoma (compound 18, a mitochondrial complex II electron transport inhibitor). Early liver weight increases and hepatocellular centrilobular hypertrophy (28 day study) were associated with thyroid follicular adenomas (compound 11, a succinate dehydrogenase inhibitor) in female animals only. Hepatic centrilobular hypertrophy (28 day studies) correlated with thyroid adenomas in males in carcinogenicity studies (compound 2, a hydroxyphenylpyruvate dioxygenase inhibitor). In contrast, treatment related, nasopharynx tumors (compound 3, an elongase inhibitor) and uterine adenocarcinoma (compound 9, a succinate dehydrogenase inhibitor) could not be correlated with findings from the short term studies examined. Eleven compounds displayed preneoplastic findings with no tumors (false negatives) and there were no compounds with no preneoplastic findings and no tumors (true negatives). This work indicates the value of examining historical, short term studies for specific, nonneoplastic findings which correlate with tumors in carcinogenicity studies, which may obviate the need for further animal carcinogenicity studies.
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Affiliation(s)
- Pratibha Mistry
- The Lenz, Hornbeam Park, Harrogate, North Yorkshire, HG2 8RE, United Kingdom
| | | | - Carol Beevers
- The Lenz, Hornbeam Park, Harrogate, North Yorkshire, HG2 8RE, United Kingdom
| | - Douglas Wolf
- Syngenta, Jealotts Hill, Bracknell, Berks, RG426EY, United Kingdom
| | - Richard A Currie
- Syngenta, Jealotts Hill, Bracknell, Berks, RG426EY, United Kingdom
| | - Rejin Salimraj
- Delphic HSE Solutions Ltd, Building B, Watchmoor Park, Camberley, Surrey, GU15 3YL, United Kingdom
| | - Paul Parsons
- The Lenz, Hornbeam Park, Harrogate, North Yorkshire, HG2 8RE, United Kingdom
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7
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Johanson SM, Ropstad E, Østby GC, Aleksandersen M, Zamaratskaia G, Boge GS, Halsne R, Trangerud C, Lyche JL, Berntsen HF, Zimmer KE, Verhaegen S. Perinatal exposure to a human relevant mixture of persistent organic pollutants: Effects on mammary gland development, ovarian folliculogenesis and liver in CD-1 mice. PLoS One 2021; 16:e0252954. [PMID: 34111182 PMCID: PMC8191980 DOI: 10.1371/journal.pone.0252954] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 05/25/2021] [Indexed: 01/09/2023] Open
Abstract
The ability of persistent organic pollutants (POPs) with endocrine disrupting properties to interfere with the developing reproductive system is of increasing concern. POPs are transferred from dams to offspring and the high sensitivity of neonates to endocrine disturbances may be caused by underdeveloped systems of metabolism and excretion. The present study aimed to characterize the effect of in utero and lactational exposure to a human relevant mixture of POPs on the female mammary gland, ovarian folliculogenesis and liver function in CD-1 offspring mice. Dams were exposed to the mixture through the diet at Control, Low or High doses (representing 0x, 5000x and 100 000x human estimated daily intake levels, respectively) from weaning and throughout mating, gestation, and lactation. Perinatally exposed female offspring exhibited altered mammary gland development and a suppressed ovarian follicle maturation. Increased hepatic cytochrome P450 enzymatic activities indirectly indicated activation of nuclear receptors and potential generation of reactive products. Hepatocellular hypertrophy was observed from weaning until 30 weeks of age and could potentially lead to hepatotoxicity. Further studies should investigate the effects of human relevant mixtures of POPs on several hormones combined with female reproductive ability and liver function.
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Affiliation(s)
- Silje Modahl Johanson
- Department of Production Animal Clinical Sciences, Norwegian University of Life Sciences, Ås, Norway
- * E-mail:
| | - Erik Ropstad
- Department of Production Animal Clinical Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - Gunn Charlotte Østby
- Department of Production Animal Clinical Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - Mona Aleksandersen
- Department of Preclinical Sciences and Pathology, Norwegian University of Life Sciences, Ås, Norway
| | - Galia Zamaratskaia
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Gudrun Seeberg Boge
- Department of Companion Animal Clinical Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - Ruth Halsne
- Division of Laboratory Medicine, Department of Forensic Sciences, Oslo University Hospital, Oslo, Norway
| | - Cathrine Trangerud
- Department of Companion Animal Clinical Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - Jan Ludvig Lyche
- Department of Paraclinical Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - Hanne Friis Berntsen
- Department of Production Animal Clinical Sciences, Norwegian University of Life Sciences, Ås, Norway
- National Institute of Occupational Health, Oslo, Norway
| | - Karin Elisabeth Zimmer
- Department of Preclinical Sciences and Pathology, Norwegian University of Life Sciences, Ås, Norway
| | - Steven Verhaegen
- Department of Production Animal Clinical Sciences, Norwegian University of Life Sciences, Ås, Norway
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8
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Renu K, Chakraborty R, Myakala H, Koti R, Famurewa AC, Madhyastha H, Vellingiri B, George A, Valsala Gopalakrishnan A. Molecular mechanism of heavy metals (Lead, Chromium, Arsenic, Mercury, Nickel and Cadmium) - induced hepatotoxicity - A review. CHEMOSPHERE 2021; 271:129735. [PMID: 33736223 DOI: 10.1016/j.chemosphere.2021.129735] [Citation(s) in RCA: 186] [Impact Index Per Article: 62.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 01/12/2021] [Accepted: 01/18/2021] [Indexed: 06/12/2023]
Abstract
Heavy metals pose a serious threat if they go beyond permissible limits in our bodies. Much heavy metal's viz. Lead, Chromium, Arsenic, Mercury, Nickel, and Cadmium pose a serious threat when they go beyond permissible limits and cause hepatotoxicity. They cause the generation of ROS which in turn causes numerous injuries and undesirable changes in the liver. Epidemiological studies have shown an increase in the levels of such heavy metals in the environment posing a serious threat to human health. Epigenetic alterations have been seen in the event of exposure to such heavy metals. Apoptosis, caspase activation as well as ultrastructural changes in the hepatocytes have also been seen due to heavy metals. Inflammation involving TNF-alpha, pro-inflammatory cytokines, MAPK, ERK pathways have been seen in the event of heavy metal hepatotoxicity. All these have shown that these heavy metals pose a serious threat to human health in particular and the environment as a whole.
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Affiliation(s)
- Kaviyarasi Renu
- Department of Biomedical Sciences, School of Bio Sciences and Technology, Vellore Institute of Technology (VIT), Vellore, Tamil Nadu, 632014, India
| | - Rituraj Chakraborty
- Department of Biomedical Sciences, School of Bio Sciences and Technology, Vellore Institute of Technology (VIT), Vellore, Tamil Nadu, 632014, India
| | - Haritha Myakala
- Department of Biomedical Sciences, School of Bio Sciences and Technology, Vellore Institute of Technology (VIT), Vellore, Tamil Nadu, 632014, India
| | - Rajeshwari Koti
- Department of Biomedical Sciences, School of Bio Sciences and Technology, Vellore Institute of Technology (VIT), Vellore, Tamil Nadu, 632014, India
| | - Ademola C Famurewa
- Department of Medical Biochemistry, Faculty of Basic Medical Sciences, College of Medicine, Alex Ekwueme Federal University, Ndufu-Alike lkwo, Nigeria
| | - Harishkumar Madhyastha
- Department of Applied Physiology, Faculty of Medicine, University of Miyazaki, Miyazaki, 889 1692, Japan
| | - Balachandar Vellingiri
- Human Molecular Cytogenetics and Stem Cell Laboratory, Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, 641 046, Tamil Nadu, India
| | - Alex George
- Jubilee Centre for Medical Research, Jubilee Mission Medical College and Research Institute, Thrissur, Kerala, India
| | - Abilash Valsala Gopalakrishnan
- Department of Biomedical Sciences, School of Bio Sciences and Technology, Vellore Institute of Technology (VIT), Vellore, Tamil Nadu, 632014, India.
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9
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Yamada T, Cohen SM, Lake BG. Critical evaluation of the human relevance of the mode of action for rodent liver tumor formation by activators of the constitutive androstane receptor (CAR). Crit Rev Toxicol 2021; 51:373-394. [PMID: 34264181 DOI: 10.1080/10408444.2021.1939654] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Many nongenotoxic chemicals have been shown to produce liver tumors in mice and/or rats by a mode of action (MOA) involving activation of the constitutive androstane receptor (CAR). Studies with phenobarbital (PB) and other compounds have identified the key events for this MOA: CAR activation; increased hepatocellular proliferation; altered foci formation; and ultimately the development of adenomas/carcinomas. In terms of human relevance, the pivotal species difference is that CAR activators are mitogenic agents in mouse and rat hepatocytes, but they do not stimulate increased hepatocellular proliferation in humans. This conclusion is supported by substantial in vitro studies with cultured rodent and human hepatocytes and also by in vivo studies with chimeric mice with human hepatocytes. Examination of the literature reveals many similarities in the hepatic effects and species differences between activators of rodent CAR and the peroxisome proliferator-activated receptor alpha (PPARα), with PPARα activators also not being mitogenic agents in human hepatocytes. Overall, a critical analysis of the available data demonstrates that the established MOA for rodent liver tumor formation by PB and other CAR activators is qualitatively not plausible for humans. This conclusion is supported by data from several human epidemiology studies.
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Affiliation(s)
- Tomoya Yamada
- Environmental Health Science Laboratory, Sumitomo Chemical Company, Ltd., Osaka, Japan
| | - Samuel M Cohen
- Department of Pathology and Microbiology, Havlik-Wall Professor of Oncology, University of Nebraska Medical Center, Nebraska Medical Center, Omaha, NE, USA
| | - Brian G Lake
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
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10
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Identification of early liver toxicity gene biomarkers using comparative supervised machine learning. Sci Rep 2020; 10:19128. [PMID: 33154507 PMCID: PMC7645727 DOI: 10.1038/s41598-020-76129-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 10/12/2020] [Indexed: 02/08/2023] Open
Abstract
Screening agrochemicals and pharmaceuticals for potential liver toxicity is required for regulatory approval and is an expensive and time-consuming process. The identification and utilization of early exposure gene signatures and robust predictive models in regulatory toxicity testing has the potential to reduce time and costs substantially. In this study, comparative supervised machine learning approaches were applied to the rat liver TG-GATEs dataset to develop feature selection and predictive testing. We identified ten gene biomarkers using three different feature selection methods that predicted liver necrosis with high specificity and selectivity in an independent validation dataset from the Microarray Quality Control (MAQC)-II study. Nine of the ten genes that were selected with the supervised methods are involved in metabolism and detoxification (Car3, Crat, Cyp39a1, Dcd, Lbp, Scly, Slc23a1, and Tkfc) and transcriptional regulation (Ablim3). Several of these genes are also implicated in liver carcinogenesis, including Crat, Car3 and Slc23a1. Our biomarker gene signature provides high statistical accuracy and a manageable number of genes to study as indicators to potentially accelerate toxicity testing based on their ability to induce liver necrosis and, eventually, liver cancer.
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11
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Corton JC, Korunes KL, Abedini J, El-Masri H, Brown J, Paul-Friedman K, Liu Y, Martini C, He S, Rooney J. Thresholds Derived From Common Measures in Rat Studies Are Predictive of Liver Tumorigenic Chemicals. Toxicol Pathol 2020; 48:857-874. [DOI: 10.1177/0192623320960412] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We hypothesized that typical tissue and clinical chemistry (ClinChem) end points measured in rat toxicity studies exhibit chemical-independent biological thresholds beyond which cancer occurs. Using the rat in vivo TG-GATES study, 75 chemicals were examined across chemical-dose-time comparisons that could be linked to liver tumor outcomes. Thresholds for liver weight to body weight (LW/BW) and 21 serum ClinChem end points were defined as the maximum and minimum values for those exposures that did not lead to liver tumors in rats. Upper thresholds were identified for LW/BW (117%), aspartate aminotransferase (195%), alanine aminotransferase (141%), alkaline phosphatase (152%), and total bilirubin (115%), and lower thresholds were identified for phospholipids (82%), relative albumin (93%), total cholesterol (82%), and total protein (94%). Thresholds derived from the TG-GATES data set were consistent across other acute and subchronic rat studies. A training set of ClinChem and LW/BW thresholds derived from a 38 chemical training set from TG-GATES was predictive of liver tumor outcomes for a test set of 37 independent TG-GATES chemicals (91%). The thresholds were most predictive when applied to 7d treatments (98%). These findings provide support that biological thresholds for common end points in rodent studies can be used to predict chemical tumorigenic potential.
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Affiliation(s)
- J. Christopher Corton
- Center for Computational Toxicology and Exposure, U.S. EPA, Research Triangle Park, NC, USA
| | - Katharine L. Korunes
- Center for Computational Toxicology and Exposure, U.S. EPA, Research Triangle Park, NC, USA
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA
| | - Jaleh Abedini
- Center for Computational Toxicology and Exposure, U.S. EPA, Research Triangle Park, NC, USA
| | - Hisham El-Masri
- Center for Computational Toxicology and Exposure, U.S. EPA, Research Triangle Park, NC, USA
| | - Jason Brown
- Center for Computational Toxicology and Exposure, U.S. EPA, Research Triangle Park, NC, USA
| | - Katie Paul-Friedman
- Center for Computational Toxicology and Exposure, U.S. EPA, Research Triangle Park, NC, USA
| | - Ying Liu
- ASRC Federal, Research Triangle Park, NC, USA
| | | | - Shihan He
- ASRC Federal, Research Triangle Park, NC, USA
| | - John Rooney
- Center for Computational Toxicology and Exposure, U.S. EPA, Research Triangle Park, NC, USA
- Oak Ridge Institute for Science and Education (ORISE), National Health and Environmental Effects Research Laboratory (NHEERL), Office of Research and Development, U.S. Environmental Protection Agency (EPA), Research Triangle Park, NC, USA
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12
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Shockley KR, Cora MC, Malarkey DE, Jackson-Humbles D, Vallant M, Collins BJ, Mutlu E, Robinson VG, Waidyanatha S, Zmarowski A, Machesky N, Richey J, Harbo S, Cheng E, Patton K, Sparrow B, Dunnick JK. Comparative toxicity and liver transcriptomics of legacy and emerging brominated flame retardants following 5-day exposure in the rat. Toxicol Lett 2020; 332:222-234. [PMID: 32679240 PMCID: PMC7903589 DOI: 10.1016/j.toxlet.2020.07.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 07/06/2020] [Accepted: 07/11/2020] [Indexed: 12/13/2022]
Abstract
The relative toxicity of three legacy and six emerging brominated flame retardants* was studied in the male Harlan Sprague Dawley rat. The hepatocellular and thyroid toxicity of each flame retardant was evaluated following five-day exposure to each of the nine flame retardants (oral gavage in corn oil) at 0.1-1000 μmol/kg body weight per day. Histopathology and transcriptomic analysis were performed on the left liver lobe. Centrilobular hypertrophy of hepatocytes and increases in liver weight were seen following exposure to two legacy (PBDE-47, HBCD) and to one emerging flame retardant (HCDBCO). Total thyroxine (TT4) concentrations were reduced to the greatest extent after PBDE-47 exposure. The PBDE-47, decaBDE, and HBCD liver transcriptomes were characterized by upregulation of liver disease-related and/or metabolic transcripts. Fewer liver disease or metabolic transcript changes were detected for the other flame retardants studied (TBB, TBPH, TBBPA-DBPE, BTBPE, DBDPE, or HCDBCO). PBDE-47 exhibited the most disruption of hepatocellular toxic endpoints, with the Nrf2 antioxidant pathway transcripts upregulated to the greatest extent, although some activation of this pathway also occurred after decaBDE, HBCD, TBB, and HCBCO exposure. These studies provide information that can be used for prioritizing the need for more in-depth brominated flame retardant toxicity studies.
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Affiliation(s)
- Keith R Shockley
- Biostatistics & Computational Biology Branch, Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, United States
| | - Michelle C Cora
- Cellular & Molecular Pathology Branch, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, United States
| | - David E Malarkey
- Cellular & Molecular Pathology Branch, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, United States
| | - Daven Jackson-Humbles
- Cellular & Molecular Pathology Branch, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, United States
| | - Molly Vallant
- Program Operations Branch, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, United States
| | - Brad J Collins
- Program Operations Branch, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, United States
| | - Esra Mutlu
- Program Operations Branch, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, United States
| | - Veronica G Robinson
- Program Operations Branch, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, United States
| | - Surayma Waidyanatha
- Program Operations Branch, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, United States
| | | | | | | | - Sam Harbo
- Battelle, Columbus, Ohio, 43210, United States
| | - Emily Cheng
- Battelle, Columbus, Ohio, 43210, United States
| | | | | | - June K Dunnick
- Toxicology Branch, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, United States.
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13
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Su RC, Meyers CM, Warner EA, Garcia JA, Refsnider JM, Lad A, Breidenbach JD, Modyanov N, Malhotra D, Haller ST, Kennedy DJ. Harmful Algal Bloom Toxicity in Lithobates catesbeiana Tadpoles. Toxins (Basel) 2020; 12:toxins12060378. [PMID: 32521650 PMCID: PMC7354472 DOI: 10.3390/toxins12060378] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/23/2020] [Accepted: 06/03/2020] [Indexed: 11/16/2022] Open
Abstract
Harmful algal blooms (HAB) have become a major health concern worldwide, not just to humans that consume and recreate on contaminated waters, but also to the fauna that inhabit the environments surrounding affected areas. HABs contain heterotrophic bacteria, cyanobacterial lipopolysaccharide, and cyanobacterial toxins such as microcystins, that can cause severe toxicity in many aquatic species as well as bioaccumulation within various organs. Thus, the possibility of trophic transference of this toxin through the food chain has potentially important health implications for other organisms in the related food web. While some species have developed adaptions to attenuate the toxic effects of HAB toxins, there are still numerous species that remain vulnerable, including Lithobates catesbeiana (American bullfrog) tadpoles. In the current study we demonstrate that acute, short-term exposure of tadpoles to HAB toxins containing 1 µg/L (1 nmol/L) of total microcystins for only 7 days results in significant liver and intestinal toxicity within tadpoles. Exposed tadpoles had increased intestinal diameter, decreased intestinal fold heights, and a constant number of intestinal folds, indicating pathological intestinal distension, similar to what is seen in various disease processes, such as toxic megacolon. HAB-toxin-exposed tadpoles also demonstrated hepatocyte hypertrophy with increased hepatocyte binucleation consistent with carcinogenic and oxidative processes within the liver. Both livers and intestines of HAB-toxin-exposed tadpoles demonstrated significant increases in protein carbonylation consistent with oxidative stress and damage. These findings demonstrate that short-term exposure to HAB toxins, including microcystins, can have significant adverse effects in amphibian populations. This acute, short-term toxicity highlights the need to evaluate the influence HAB toxins may have on other vulnerable species within the food web and how those may ultimately also impact human health.
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Affiliation(s)
- Robin C. Su
- Department of Medicine, The University of Toledo College of Medicine and Life Sciences, 3000 Arlington Avenue, Toledo, OH 43614, USA; (R.C.S.); (E.A.W.); (A.L.); (J.D.B.); (D.M.)
| | - Casey M. Meyers
- Department of Biology, Wittenberg University, Springfield, OH 45504, USA;
| | - Emily A. Warner
- Department of Medicine, The University of Toledo College of Medicine and Life Sciences, 3000 Arlington Avenue, Toledo, OH 43614, USA; (R.C.S.); (E.A.W.); (A.L.); (J.D.B.); (D.M.)
| | - Jessica A. Garcia
- Department of Environmental Sciences, The University of Toledo, Toledo, OH 43606, USA; (J.A.G.); (J.M.R.)
| | - Jeanine M. Refsnider
- Department of Environmental Sciences, The University of Toledo, Toledo, OH 43606, USA; (J.A.G.); (J.M.R.)
| | - Apurva Lad
- Department of Medicine, The University of Toledo College of Medicine and Life Sciences, 3000 Arlington Avenue, Toledo, OH 43614, USA; (R.C.S.); (E.A.W.); (A.L.); (J.D.B.); (D.M.)
| | - Joshua D. Breidenbach
- Department of Medicine, The University of Toledo College of Medicine and Life Sciences, 3000 Arlington Avenue, Toledo, OH 43614, USA; (R.C.S.); (E.A.W.); (A.L.); (J.D.B.); (D.M.)
| | - Nikolai Modyanov
- Department of Physiology and Pharmacology, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA;
| | - Deepak Malhotra
- Department of Medicine, The University of Toledo College of Medicine and Life Sciences, 3000 Arlington Avenue, Toledo, OH 43614, USA; (R.C.S.); (E.A.W.); (A.L.); (J.D.B.); (D.M.)
| | - Steven T. Haller
- Department of Medicine, The University of Toledo College of Medicine and Life Sciences, 3000 Arlington Avenue, Toledo, OH 43614, USA; (R.C.S.); (E.A.W.); (A.L.); (J.D.B.); (D.M.)
- Department of Medical Microbiology and Immunology, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
- Correspondence: (S.T.H.); (D.J.K.); Tel.: +1-419-383-6822 (D.J.K. & S.T.H.)
| | - David J. Kennedy
- Department of Medicine, The University of Toledo College of Medicine and Life Sciences, 3000 Arlington Avenue, Toledo, OH 43614, USA; (R.C.S.); (E.A.W.); (A.L.); (J.D.B.); (D.M.)
- Department of Medical Microbiology and Immunology, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
- Correspondence: (S.T.H.); (D.J.K.); Tel.: +1-419-383-6822 (D.J.K. & S.T.H.)
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14
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Felter SP, Boobis AR, Botham PA, Brousse A, Greim H, Hollnagel HM, Sauer UG. Hazard identification, classification, and risk assessment of carcinogens: too much or too little? - Report of an ECETOC workshop. Crit Rev Toxicol 2020; 50:72-95. [PMID: 32133908 DOI: 10.1080/10408444.2020.1727843] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) organized a workshop "Hazard Identification, Classification and Risk Assessment of Carcinogens: Too Much or Too Little?" to explore the scientific limitations of the current binary carcinogenicity classification scheme that classifies substances as either carcinogenic or not. Classification is often based upon the rodent 2-year bioassay, which has scientific limitations and is not necessary to predict whether substances are likely human carcinogens. By contrast, tiered testing strategies founded on new approach methodologies (NAMs) followed by subchronic toxicity testing, as necessary, are useful to determine if a substance is likely carcinogenic, by which mode-of-action effects would occur and, for non-genotoxic carcinogens, the dose levels below which the key events leading to carcinogenicity are not affected. Importantly, the objective is not for NAMs to mimic high-dose effects recorded in vivo, as these are not relevant to human risk assessment. Carcinogenicity testing at the "maximum tolerated dose" does not reflect human exposure conditions, but causes major disturbances of homeostasis, which are very unlikely to occur at relevant human exposure levels. The evaluation of findings should consider biological relevance and not just statistical significance. Using this approach, safe exposures to non-genotoxic substances can be established.
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Affiliation(s)
| | | | | | - Alice Brousse
- European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC), Brussels, Belgium
| | | | | | - Ursula G Sauer
- Scientific Consultancy - Animal Welfare, Neubiberg, Germany
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15
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Lee OW, Austin S, Gamma M, Cheff DM, Lee TD, Wilson KM, Johnson J, Travers J, Braisted JC, Guha R, Klumpp-Thomas C, Shen M, Hall MD. Cytotoxic Profiling of Annotated and Diverse Chemical Libraries Using Quantitative High-Throughput Screening. SLAS DISCOVERY : ADVANCING LIFE SCIENCES R & D 2020; 25:9-20. [PMID: 31498718 PMCID: PMC10791069 DOI: 10.1177/2472555219873068] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Cell-based phenotypic screening is a commonly used approach to discover biological pathways, novel drug targets, chemical probes, and high-quality hit-to-lead molecules. Many hits identified from high-throughput screening campaigns are ruled out through a series of follow-up potency, selectivity/specificity, and cytotoxicity assays. Prioritization of molecules with little or no cytotoxicity for downstream evaluation can influence the future direction of projects, so cytotoxicity profiling of screening libraries at an early stage is essential for increasing the likelihood of candidate success. In this study, we assessed the cell-based cytotoxicity of nearly 10,000 compounds in the National Institutes of Health, National Center for Advancing Translational Sciences annotated libraries and more than 100,000 compounds in a diversity library against four normal cell lines (HEK 293, NIH 3T3, CRL-7250, and HaCat) and one cancer cell line (KB 3-1, a HeLa subline). This large-scale library profiling was analyzed for overall screening outcomes, hit rates, pan-activity, and selectivity. For the annotated library, we also examined the primary targets and mechanistic pathways regularly associated with cell death. To our knowledge, this is the first study to use high-throughput screening to profile a large screening collection (>100,000 compounds) for cytotoxicity in both normal and cancer cell lines. The results generated here constitute a valuable resource for the scientific community and provide insight into the extent of cytotoxic compounds in screening libraries, allowing for the identification and avoidance of compounds with cytotoxicity during high-throughput screening campaigns.
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Affiliation(s)
- Olivia W. Lee
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Shelley Austin
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Madison Gamma
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Dorian M. Cheff
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Tobie D. Lee
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Kelli M. Wilson
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Joseph Johnson
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Jameson Travers
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - John C. Braisted
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Rajarshi Guha
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Carleen Klumpp-Thomas
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Min Shen
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Matthew D. Hall
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
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16
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Sacaan A, Thibault S, Khan KN. Central nervous system tumors in 2-year rat carcinogenicity studies: perspectives on human risk assessment. J Toxicol Sci 2019; 44:643-655. [PMID: 31588056 DOI: 10.2131/jts.44.643] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Rodent in vivo carcinogenicity bioassays are required for human risk assessment and have been utilized in this capacity for decades. Accordingly, there is an abundance of data that could be accessed and analyzed to better understand the translatability of xenobiotic-induced rodent tumors to human risk assessment. In the past decade, various groups have published assessments of the value garnered by these life-time rodent studies. Results and recommendations from the International Council for Harmonization Expert Working Group (ICH-S1 EWG) on the predictability of the current testing paradigm and proposal for an integrated approach to human carcinogenicity risk assessment are pending. Central nervous system (CNS) tumors in rats are rare and translatability to human remains unknown. This review focuses on microglial cell tumors (MCT) of the CNS in rats including its classification, nomenclature, incidence and translatability to human risk assessment. Based on emerging immunohistochemistry (IHC) characterization, glial tumors previously thought of astrocytic origin are more likely MCTs. These may be considered rodent specific and glucose dysregulation may be one component contributing to their formation. Based on review of the literature, MCTs are rarely diagnosed in humans, thus this tumor type may be rat-specific. We propose to include MCTs as a tumor type in revised International Harmonization of Nomenclature and Diagnostic Criteria (INHAND) classification and all glial tumors to be classified as MCTs unless proven otherwise by IHC.
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Affiliation(s)
- Aida Sacaan
- Pfizer Inc. Drug Safety Research and Development
| | | | - K Nasir Khan
- Pfizer Inc. Drug Safety Research and Development
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17
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Shao K, Chen Q, Wang Z. Quantifying association between liver tumor incidence and early-stage liver weight increase - An NTP data analysis. Toxicol Rep 2019; 6:674-682. [PMID: 31360640 PMCID: PMC6639686 DOI: 10.1016/j.toxrep.2019.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 06/28/2019] [Accepted: 07/06/2019] [Indexed: 11/06/2022] Open
Abstract
Liver tumor incidence and liver weight data were collected from 593 NTP studies. Correlation between BMDs from these two types of data were quantified. In a general analysis, the correlation coefficient can be as high as 0.78. Early liver weight change may be used as an indicator for chemical tumorigenesis.
Two-year toxicology and carcinogenesis rodent studies conducted at the National Toxicology Program (NTP) are used to identify potential adverse health effects in humans due to chemical exposure, including cancer. Liver tumor, the most frequently diagnosed tumor type of chemically induced neoplastic effects documented in NTP’s carcinogenicity studies, is usually difficult to be detected at early stage due to the inconspicuous symptoms. However, the abnormal growth of liver cells can lead to liver weight increase, so it is hypothesized that liver tumor incidence is associated with early stage liver weight increase. In this study, the association between liver weight increase and liver tumor incidence are quantified by (1) calculating the correlation coefficient of and (2) building quantitative linear relationship between benchmark dose estimates derived from these two types of data collected from NTP studies. Together with 151 chemical/species/sex combinations of liver tumor data showing positive evidence collected from 76 NTP long-term studies, short-term liver weight data reported in the same NTP report were extracted to be paired with the liver tumor data for the analyses. Results show that the estimated correlation coefficients (as high as 0.78) along with the adequately fitted linear models suggest that the association between relative liver weight increase and aggregated liver tumor incidence are relatively strong. Additional analyses focused on some more specific situations (e.g., specific tumor type or specific strain/sex combination) further confirmed the strong association. Given the design of this study, the interpretation of the findings is not that liver weight increase can be used to predict liver tumor incidence, instead, evident increase in liver weight might be used as a reason to prioritize the test article for a two-year toxicology and carcinogenesis study.
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Affiliation(s)
- Kan Shao
- Department of Environmental and Occupational Health, School of Public Health, Indiana University, Bloomington, IN, 47405, USA
| | - Qiran Chen
- Department of Environmental and Occupational Health, School of Public Health, Indiana University, Bloomington, IN, 47405, USA
| | - Zemin Wang
- Department of Environmental and Occupational Health, School of Public Health, Indiana University, Bloomington, IN, 47405, USA
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18
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Doe JE, Boobis AR, Dellarco V, Fenner-Crisp PA, Moretto A, Pastoor TP, Schoeny RS, Seed JG, Wolf DC. Chemical carcinogenicity revisited 2: Current knowledge of carcinogenesis shows that categorization as a carcinogen or non-carcinogen is not scientifically credible. Regul Toxicol Pharmacol 2019; 103:124-129. [DOI: 10.1016/j.yrtph.2019.01.024] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 01/09/2019] [Accepted: 01/16/2019] [Indexed: 11/28/2022]
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19
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Cohen SM, Boobis AR, Dellarco VL, Doe JE, Fenner-Crisp PA, Moretto A, Pastoor TP, Schoeny RS, Seed JG, Wolf DC. Chemical carcinogenicity revisited 3: Risk assessment of carcinogenic potential based on the current state of knowledge of carcinogenesis in humans. Regul Toxicol Pharmacol 2019; 103:100-105. [DOI: 10.1016/j.yrtph.2019.01.017] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 01/04/2019] [Accepted: 01/07/2019] [Indexed: 01/27/2023]
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20
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Kobets T, Iatropoulos MJ, Williams GM. Mechanisms of DNA-reactive and epigenetic chemical carcinogens: applications to carcinogenicity testing and risk assessment. Toxicol Res (Camb) 2019; 8:123-145. [PMID: 30997017 PMCID: PMC6417487 DOI: 10.1039/c8tx00250a] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Accepted: 12/18/2018] [Indexed: 01/03/2023] Open
Abstract
Chemicals with carcinogenic activity in either animals or humans produce increases in neoplasia through diverse mechanisms. One mechanism is reaction with nuclear DNA. Other mechanisms consist of epigenetic effects involving either modifications of regulatory macromolecules or perturbation of cellular regulatory processes. The basis for distinguishing between carcinogens that have either DNA reactivity or an epigenetic activity as their primary mechanism of action is detailed in this review. In addition, important applications of information on these mechanisms of action to carcinogenicity testing and human risk assessment are discussed.
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Affiliation(s)
- Tetyana Kobets
- Department of Pathology , New York Medical College , Valhalla , NY 10595 , USA . ; ; Tel: +1 914-594-3105
| | - Michael J Iatropoulos
- Department of Pathology , New York Medical College , Valhalla , NY 10595 , USA . ; ; Tel: +1 914-594-3105
| | - Gary M Williams
- Department of Pathology , New York Medical College , Valhalla , NY 10595 , USA . ; ; Tel: +1 914-594-3105
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21
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FEMA GRAS assessment of natural flavor complexes: Citrus-derived flavoring ingredients. Food Chem Toxicol 2018; 124:192-218. [PMID: 30481573 DOI: 10.1016/j.fct.2018.11.052] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 11/19/2018] [Accepted: 11/23/2018] [Indexed: 01/06/2023]
Abstract
In 2015, the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA) initiated a re-evaluation of the safety of over 250 natural flavor complexes (NFCs) used as flavoring ingredients. This publication is the first in a series and summarizes the evaluation of 54 Citrus-derived NFCs using the procedure outlined in Smith et al. (2005) and updated in Cohen et al. (2018) to evaluate the safety of naturally-occurring mixtures for their intended use as flavoring ingredients. The procedure relies on a complete chemical characterization of each NFC intended for commerce and organization of each NFC's chemical constituents into well-defined congeneric groups. The safety of the NFC is evaluated using the well-established and conservative threshold of toxicological concern (TTC) concept in addition to data on absorption, metabolism and toxicology of members of the congeneric groups and the NFC under evaluation. As a result of the application of the procedure, 54 natural flavor complexes derived from botanicals of the Citrus genus were affirmed as generally recognized as safe (GRAS) under their conditions of intended use as flavoring ingredients based on an evaluation of each NFC and the constituents and congeneric groups therein.
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22
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Yamada T. Case examples of an evaluation of the human relevance of the pyrethroids/pyrethrins-induced liver tumours in rodents based on the mode of action. Toxicol Res (Camb) 2018; 7:681-696. [PMID: 30090614 PMCID: PMC6062351 DOI: 10.1039/c7tx00288b] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 01/10/2018] [Indexed: 01/01/2023] Open
Abstract
Rodent carcinogenicity studies are useful for screening for human carcinogens but they are not perfect. Some modes of action (MOAs) lead to cancers in both experimental rodents and humans, but others that lead to cancers in rodents do not do so in humans. Therefore, analysing the MOAs by which chemicals produce tumours in rodents and determining the relevance of such tumour data for human risk are critical. Recently, experimental data were obtained as case examples of an evaluation of the human relevance of pyrethroid (metofluthrin and momfluorothrin)- and pyrethrins-induced liver tumours in rats based on MOA. The MOA analysis, based on the International Programme on Chemical Safety (IPCS) framework, concluded that experimental data strongly support that the postulated MOA for metofluthrin-, momfluorothrin- and pyrethrins-produced rat hepatocellular tumours is mediated by constitutive androstane receptor (CAR) activation. Since metofluthrin and momfluorothrin are close structural analogues, reproducible outcomes for both chemicals provide confidence in the MOA findings. Furthermore, cultured human hepatocyte studies and humanized chimeric mouse liver studies demonstrated species difference between human hepatocytes (refractory to the mitogenic effects of these compounds) and rat hepatocytes (sensitive to their mitogenic effects). These data strongly support the hypothesis that the CAR-mediated MOA for liver tumorigenesis is of low carcinogenic risk for humans. In this research, in addition to cultured human hepatocyte studies, the usefulness of the humanized chimeric liver mouse models was clearly demonstrated. These data substantially influenced decisions in regulatory toxicology. In this review I comprehensively discuss the human relevance of the CAR-mediated MOA for rodent liver tumorigenesis based on published information, including our recent molecular research on CAR-mediated MOA.
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Affiliation(s)
- Tomoya Yamada
- Environmental Health Science Laboratory , Sumitomo Chemical Co. , Ltd , 1-98 , 3-Chome , Kasugade-Naka , Konohana-ku , Osaka 554-8558 , Japan . ; ; Tel: +81-66466-5322
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23
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Rooney JP, Ryan N, Chorley BN, Hester SD, Kenyon EM, Schmid JE, George BJ, Hughes MF, Sey YM, Tennant A, MacMillan DK, Simmons JE, McQueen CA, Pandiri A, Wood CE, Corton JC. From the Cover: Genomic Effects of Androstenedione and Sex-Specific Liver Cancer Susceptibility in Mice. Toxicol Sci 2018; 160:15-29. [PMID: 28973534 DOI: 10.1093/toxsci/kfx153] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Current strategies for predicting carcinogenic mode of action for nongenotoxic chemicals are based on identification of early key events in toxicity pathways. The goal of this study was to evaluate short-term key event indicators resulting from exposure to androstenedione (A4), an androgen receptor agonist and known liver carcinogen in mice. Liver cancer is more prevalent in men compared with women, but androgen-related pathways underlying this sex difference have not been clearly identified. Short-term hepatic effects of A4 were compared with reference agonists of the estrogen receptor (ethinyl estradiol, EE) and glucocorticoid receptor (prednisone, PRED). Male B6C3F1 mice were exposed for 7 or 28 days to A4, EE, or PRED. EE increased and PRED suppressed hepatocyte proliferation, while A4 had no detectable effects. In a microarray analysis, EE and PRED altered >3000 and >670 genes, respectively, in a dose-dependent manner, whereas A4 did not significantly alter any genes. Gene expression was subsequently examined in archival liver samples from male and female B6C3F1 mice exposed to A4 for 90 days. A4 altered more genes in females than males and did not alter expression of genes linked to activation of the mitogenic xenobiotic receptors AhR, CAR, and PPARα in either sex. A gene expression biomarker was used to show that in female mice, the high dose of A4 activated the growth hormone-regulated transcription factor STAT5b, which controls sexually dimorphic gene expression in the liver. These findings suggest that A4 induces subtle age-related effects on STAT5b signaling that may contribute to the higher risk of liver cancer in males compared with females.
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Affiliation(s)
- John P Rooney
- Office of Research and Development, Oak Ridge Institute for Science and Education (ORISE).,Integrated Systems Toxicology Division
| | - Natalia Ryan
- Office of Research and Development, Oak Ridge Institute for Science and Education (ORISE).,Integrated Systems Toxicology Division
| | | | | | | | | | | | | | | | | | | | | | - Charlene A McQueen
- Office of the Director, National Health and Environmental Effects Research Laboratory (NHEERL), U.S. EPA, Research Triangle Park, North Carolina, 27711
| | - Arun Pandiri
- National Toxicology Program, Research Triangle Park, North Carolina, 27711
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24
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Han R, Zhang F, Wan C, Liu L, Zhong Q, Ding W. Effect of perfluorooctane sulphonate-induced Kupffer cell activation on hepatocyte proliferation through the NF-κB/TNF-α/IL-6-dependent pathway. CHEMOSPHERE 2018; 200:283-294. [PMID: 29494909 DOI: 10.1016/j.chemosphere.2018.02.137] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 02/21/2018] [Accepted: 02/22/2018] [Indexed: 05/18/2023]
Abstract
Perfluorooctane sulfonate (PFOS), one member of polyfluoroalkyl chemicals (PFASs), persist in the environment and are found in relatively high concentrations in animal livers. PFOS has been shown to induce tumour of the liver in rats following chronic dietary administration. However, the molecular mechanisms involved in PFOS-induced hepatocellular hypertrophy are still not well characterized. In this study, male Sprague-Dawley rats were daily gavaged with PFOS (1 or 10 mg/kg body weight) for 28 days. Rat primary cultured Kupffer cells or hepatocytes were exposed to 100 μM PFOS for 0-48 h. Our results showed that PFOS exposure caused serious hepatocellular damage and obvious inflammatory cell infiltration and increased serum tumour necrosis factor-ɑ (TNF-α) and interleukin-6 (IL-6) levels. Particularly, PFOS exposure triggered Kupffer cell activation and significantly upregulated the expression of proliferating cell nuclear antigen (PCNA), c-Jun, c-MYC and Cyclin D1 (CyD1) in liver. In vitro, PFOS significantly induced production of TNF-α and IL-6 in Kupffer cells and increased PCNA, c-Jun, c-MYC and CyD1 expression in the primary hepatocytes co-cultured with Kupffer cells. However, Kupffer cell activation was mostly abolished by anti-TNF-α or anti-IL6 treatment. Furthermore, blockage of TNF-α and IL-6 significantly inhibited hepatocyte proliferation by gadolinium chloride (GdCl3) pre-treatment in PFOS-treated mice and primary cultured Kupffer cells. On the other hand, NF-κB inhibitor (PDTC) and c-Jun amino-terminal kinase (JNK) inhibitor (SP600125) significantly inhibited production of PFOS-induced TNF-α and IL-6. Taken together, these data suggest that PFOS induces Kupffer cell activation, leading to hepatocyte proliferation by through the NF-κB/TNF-ɑ/IL-6-dependent pathway.
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Affiliation(s)
- Rui Han
- Laboratory of Environment and Health, College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Fang Zhang
- Laboratory of Environment and Health, College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Chong Wan
- Laboratory of Environment and Health, College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Limin Liu
- Laboratory of Environment and Health, College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Qiang Zhong
- Department of Emergency Medicine, Tongji Hospital Affiliated to Tongji Medical College Huazhong, University of Science & Technology, Wuhan, China.
| | - Wenjun Ding
- Laboratory of Environment and Health, College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.
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25
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Dunnick JK, Pandiri AR, Merrick BA, Kissling GE, Cunny H, Mutlu E, Waidyanatha S, Sills R, Hong HL, Ton TV, Maynor T, Recio L, Phillips SL, Devito MJ, Brix A. Carcinogenic activity of pentabrominated diphenyl ether mixture (DE-71) in rats and mice. Toxicol Rep 2018; 5:615-624. [PMID: 29868454 PMCID: PMC5984199 DOI: 10.1016/j.toxrep.2018.05.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 05/11/2018] [Accepted: 05/14/2018] [Indexed: 01/19/2023] Open
Abstract
Pentabrominated diphenyl ether (PBDE) mixture was a multispecies carcinogen causing liver tumors in male and female rats and mice. Hras or Ctnnb1 mutations characterized the PBDE-induced liver tumors. PBDE-induced liver tumors increased with increasing PBDE exposure.
Pentabrominated diphenyl ether (PBDE) flame retardants have been phased out in Europe and in the United States, but these lipid soluble chemicals persist in the environment and are found human and animal tissues. PBDEs have limited genotoxic activity. However, in a 2-year cancer study of a PBDE mixture (DE-71) (0, 3, 15, or 50 mg/kg (rats); 0, 3, 30, or 100 mg/kg (mice)) there were treatment-related liver tumors in male and female Wistar Han rats [Crl:WI(Han) after in utero/postnatal/adult exposure, and in male and female B6C3F1 mice, after adult exposure. In addition, there was evidence for a treatment-related carcinogenic effect in the thyroid and pituitary gland tumor in male rats, and in the uterus (stromal polyps/stromal sarcomas) in female rats. The treatment-related liver tumors in female rats were unrelated to the AhR genotype status, and occurred in animals with wild, mutant, or heterozygous Ah receptor. The liver tumors in rats and mice had treatment-related Hras and Ctnnb mutations, respectively. The PBDE carcinogenic activity could be related to oxidative damage, disruption of hormone homeostasis, and molecular and epigenetic changes in target tissue. Further work is needed to compare the PBDE toxic effects in rodents and humans.
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Affiliation(s)
- J K Dunnick
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - A R Pandiri
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - B A Merrick
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - G E Kissling
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - H Cunny
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - E Mutlu
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - S Waidyanatha
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - R Sills
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - H L Hong
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - T V Ton
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - T Maynor
- Integrated Laboratory Systems, Research Triangle Park, NC 27709, USA
| | - L Recio
- Integrated Laboratory Systems, Research Triangle Park, NC 27709, USA
| | - S L Phillips
- Integrated Laboratory Systems, Research Triangle Park, NC 27709, USA
| | - M J Devito
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - A Brix
- EPL, Inc., Research Triangle Park, NC 27709, USA
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26
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Gulay KCM, Tanaka IB, Komura J, Tanaka S. Effects of Continuous Gamma-Ray Exposure In Utero in B6C3F1 Mice on Gestation Day 18 and at 10 Weeks of Age. Radiat Res 2018; 189:425-440. [PMID: 29437533 DOI: 10.1667/rr14863.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Pregnant C57BL/6JJcl mice were exposed to γ rays at low dose rate (20 mGy/day, LDR) or medium dose rate (200 and 400 mGy/day, MDR) from gestation day (GD) 0-18 to total accumulated doses of 360, 3,600 and 7,200 mGy, respectively. An additional group of pregnant mice were acutely exposed to 2 Gy at high dose rate (HDR) of 0.77 Gy/min on GD 11. In experiment 1, fetuses collected via cesarean section on GD 18 were examined for external and skeletal abnormalities. While the results of LDR exposure (20 mGy/day) did not significantly differ from the nonirradiated controls in all parameters examined, MDR (200 and 400 mGy/day) and acute HDR (2 Gy) exposure caused growth retardation and significantly increased incidence of unossified bones. Increased incidence of external abnormalities was observed only in the acute HDR group. In experiment 2, the dams were allowed to give birth and the pups were clinically monitored and weighed periodically until 10 weeks of age when they were sacrificed and subjected to pathological examination. Pups exposed at MDRs of 200 and 400 mGy/dayand at acute HDR of 0.77 Gy/min had lower bodyweights from weaning (3 weeks) to 10 weeks of age except for females exposed to 400 mGy/day MDR. None of the pups exposed to an acute 2 Gy dose on GD 11 survived to 10 weeks of age. Histopathological changes were not significantly different between the nonirradiated control and the 20 mGy/day LDR groups. However, at both MDR exposures of 200 and 400 mGy/day. gonadal (testes and ovary) hypoplasia/atrophy was observed in all the 10-week-old pups. Our results show that in utero LDR exposure to 20 mGy/day for the entire gestation period did not cause any significant effect in pups when compared to the nonirradiated controls up to 10 weeks of age. However, pups exposed in utero to MDRs showed dose-related growth retardation with delayed ossifications (400 mGy/day) and gonadal hypoplasia/atrophy. These findings suggest that increased post-implantation loss in dams exposed at MDR is due to early embryonic deaths resulting in early resorption.
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Affiliation(s)
- K C M Gulay
- Department of Radiobiology, Institute for Environmental Sciences, 1-7, Ienomae, Obuchi, Rokkasho-mura, Kamikita-gun, Aomori 039-3212, Japan
| | - I B Tanaka
- Department of Radiobiology, Institute for Environmental Sciences, 1-7, Ienomae, Obuchi, Rokkasho-mura, Kamikita-gun, Aomori 039-3212, Japan
| | - J Komura
- Department of Radiobiology, Institute for Environmental Sciences, 1-7, Ienomae, Obuchi, Rokkasho-mura, Kamikita-gun, Aomori 039-3212, Japan
| | - S Tanaka
- Department of Radiobiology, Institute for Environmental Sciences, 1-7, Ienomae, Obuchi, Rokkasho-mura, Kamikita-gun, Aomori 039-3212, Japan
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27
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Modernizing Human Cancer Risk Assessment of Therapeutics. Trends Pharmacol Sci 2017; 39:232-247. [PMID: 29242029 DOI: 10.1016/j.tips.2017.11.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 11/17/2017] [Accepted: 11/17/2017] [Indexed: 12/14/2022]
Abstract
Cancer risk assessment of therapeutics is plagued by poor translatability of rodent models of carcinogenesis. In order to overcome this fundamental limitation, new approaches are needed that enable us to evaluate cancer risk directly in humans and human-based cellular models. Our enhanced understanding of the mechanisms of carcinogenesis and the influence of human genome sequence variation on cancer risk motivates us to re-evaluate how we assess the carcinogenic risk of therapeutics. This review will highlight new opportunities for applying this knowledge to the development of a battery of human-based in vitro models and biomarkers for assessing cancer risk of novel therapeutics.
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28
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Liu S, Kawamoto T, Morita O, Yoshinari K, Honda H. Discriminating between adaptive and carcinogenic liver hypertrophy in rat studies using logistic ridge regression analysis of toxicogenomic data: The mode of action and predictive models. Toxicol Appl Pharmacol 2017; 318:79-87. [PMID: 28108177 DOI: 10.1016/j.taap.2017.01.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 01/11/2017] [Accepted: 01/13/2017] [Indexed: 10/20/2022]
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29
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Woutersen RA, Soffers AE, Kroese ED, Krul CA, van der Laan JW, van Benthem J, Luijten M. Prediction of carcinogenic potential of chemicals using repeated-dose (13-week) toxicity data. Regul Toxicol Pharmacol 2016; 81:242-249. [DOI: 10.1016/j.yrtph.2016.09.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 08/30/2016] [Accepted: 09/05/2016] [Indexed: 12/11/2022]
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30
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van der Laan JW, Buitenhuis WHW, Wagenaar L, Soffers AEMF, van Someren EP, Krul CAM, Woutersen RA. Prediction of the Carcinogenic Potential of Human Pharmaceuticals Using Repeated Dose Toxicity Data and Their Pharmacological Properties. Front Med (Lausanne) 2016; 3:45. [PMID: 27790617 PMCID: PMC5063850 DOI: 10.3389/fmed.2016.00045] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 09/20/2016] [Indexed: 01/06/2023] Open
Abstract
In an exercise designed to reduce animal use, we analyzed the results of rat subchronic toxicity studies from 289 pharmaceutical compounds with the aim to predict the tumor outcome of carcinogenicity studies in this species. The results were obtained from the assessment reports available at the Medicines Evaluation Board of the Netherlands for 289 pharmaceutical compounds that had been shown to be non-genotoxic. One hundred forty-three of the 239 compounds not inducing putative preneoplastic lesions in the subchronic study did not induce tumors in the carcinogenicity study [true negatives (TNs)], whereas 96 compounds were categorized as false negatives (FNs) because tumors were observed in the carcinogenicity study. Of the remaining 50 compounds, 31 showed preneoplastic lesions in the subchronic study and tumors in the carcinogenicity study [true positives (TPs)], and 19 only showed preneoplastic lesions in subchronic studies but no tumors in the carcinogenicity study [false positives (FPs)]. In addition, we then re-assessed the prediction of the tumor outcome by integrating the pharmacological properties of these compounds. These pharmacological properties were evaluated with respect to the presence or absence of a direct or indirect proliferative action. We found support for the absence of cellular proliferation for 204 compounds (TN). For 67 compounds, the presence of cellular hyperplasia as evidence for proliferative action could be found (TP). Therefore, this approach resulted in an ability to predict non-carcinogens at a success rate of 92% and the ability to detect carcinogens at 98%. The combined evaluation of pharmacological and histopathological endpoints eventually led to only 18 unknown outcomes (17 categorized as FN and 1 as FP), thereby enhancing both the negative and positive predictivity of an evaluation based upon histopathological evaluation only. The data show the added value of a consideration of the pharmacological properties of compounds in relation to potential class effects, both in the negative and positive direction. A high negative and a high positive predictivity will both result in waiving the need for conducting 2-year rat carcinogenicity studies, if this is accepted by Regulatory Authorities, which will save large numbers of animals and reduce drug development costs and time.
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Affiliation(s)
- Jan Willem van der Laan
- Medicines Evaluation Board, Utrecht, Netherlands
- Division of Toxicology, Leiden Academic Center for Drug Research, Leiden, Netherlands
| | | | | | - Ans E. M. F. Soffers
- Division of Toxicology, Wageningen University and Research Centre, Wageningen, Netherlands
| | | | | | - Ruud A. Woutersen
- Division of Toxicology, Wageningen University and Research Centre, Wageningen, Netherlands
- TNO Innovation for Life, Zeist, Netherlands
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31
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Cohen SM, Arnold LL. Critical role of toxicologic pathology in a short-term screen for carcinogenicity. J Toxicol Pathol 2016; 29:215-227. [PMID: 27821906 PMCID: PMC5097964 DOI: 10.1293/tox.2016-0036] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Accepted: 05/09/2016] [Indexed: 12/28/2022] Open
Abstract
Carcinogenic potential of chemicals is currently evaluated using a two year bioassay in rodents. Numerous difficulties are known for this assay, most notably, the lack of information regarding detailed dose response and human relevance of any positive findings. A screen for carcinogenic activity has been proposed based on a 90 day screening assay. Chemicals are first evaluated for proliferative activity in various tissues. If negative, lack of carcinogenic activity can be concluded. If positive, additional evaluation for DNA reactivity, immunosuppression, and estrogenic activity are evaluated. If these are negative, additional efforts are made to determine specific modes of action in the animal model, with a detailed evaluation of the potential relevance to humans. Applications of this approach are presented for liver and urinary bladder. Toxicologic pathology is critical for all of these evaluations, including a detailed histopathologic evaluation of the 90 day assay, immunohistochemical analyses for labeling index, and involvement in a detailed mode of action analysis. Additionally, the toxicologic pathologist needs to be involved with molecular evaluations and evaluations of new molecularly developed animal models. The toxicologic pathologist is uniquely qualified to provide the expertise needed for these evaluations.
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Affiliation(s)
- Samuel M. Cohen
- Department of Pathology and Microbiology, University of Nebraska Medical Center, 983135 Omaha, NE 68198-3135, USA
| | - Lora L. Arnold
- Department of Pathology and Microbiology, University of Nebraska Medical Center, 983135 Omaha, NE 68198-3135, USA
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32
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Hill T, Nelms MD, Edwards SW, Martin M, Judson R, Corton JC, Wood CE. Editor’s Highlight: Negative Predictors of Carcinogenicity for Environmental Chemicals. Toxicol Sci 2016; 155:157-169. [DOI: 10.1093/toxsci/kfw195] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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Luijten M, Olthof ED, Hakkert BC, Rorije E, van der Laan JW, Woutersen RA, van Benthem J. An integrative test strategy for cancer hazard identification. Crit Rev Toxicol 2016; 46:615-39. [PMID: 27142259 DOI: 10.3109/10408444.2016.1171294] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Assessment of genotoxic and carcinogenic potential is considered one of the basic requirements when evaluating possible human health risks associated with exposure to chemicals. Test strategies currently in place focus primarily on identifying genotoxic potential due to the strong association between the accumulation of genetic damage and cancer. Using genotoxicity assays to predict carcinogenic potential has the significant drawback that risks from non-genotoxic carcinogens remain largely undetected unless carcinogenicity studies are performed. Furthermore, test systems already developed to reduce animal use are not easily accepted and implemented by either industries or regulators. This manuscript reviews the test methods for cancer hazard identification that have been adopted by the regulatory authorities, and discusses the most promising alternative methods that have been developed to date. Based on these findings, a generally applicable tiered test strategy is proposed that can be considered capable of detecting both genotoxic as well as non-genotoxic carcinogens and will improve understanding of the underlying mode of action. Finally, strengths and weaknesses of this new integrative test strategy for cancer hazard identification are presented.
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Affiliation(s)
- Mirjam Luijten
- a Centre for Health Protection, National Institute for Public Health and the Environment (RIVM) , Bilthoven , the Netherlands
| | - Evelyn D Olthof
- a Centre for Health Protection, National Institute for Public Health and the Environment (RIVM) , Bilthoven , the Netherlands
| | - Betty C Hakkert
- b Centre for Safety of Substances and Products, National Institute for Public Health and the Environment (RIVM) , Bilthoven , the Netherlands
| | - Emiel Rorije
- b Centre for Safety of Substances and Products, National Institute for Public Health and the Environment (RIVM) , Bilthoven , the Netherlands
| | | | - Ruud A Woutersen
- d Netherlands Organization for Applied Scientific Research (TNO) , Zeist , the Netherlands
| | - Jan van Benthem
- a Centre for Health Protection, National Institute for Public Health and the Environment (RIVM) , Bilthoven , the Netherlands
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34
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Asaoka Y, Togashi Y, Mutsuga M, Imura N, Miyoshi T, Miyamoto Y. Histopathological image analysis of chemical-induced hepatocellular hypertrophy in mice. ACTA ACUST UNITED AC 2016; 68:233-9. [DOI: 10.1016/j.etp.2015.12.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 12/11/2015] [Accepted: 12/15/2015] [Indexed: 11/27/2022]
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35
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Review of genotoxicity and rat carcinogenicity investigations with astaxanthin. Regul Toxicol Pharmacol 2016; 75:5-19. [DOI: 10.1016/j.yrtph.2015.12.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 12/02/2015] [Accepted: 12/17/2015] [Indexed: 11/21/2022]
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36
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Boorman GA, Foster JR, Laast VA, Francke S. Regulatory Forum Opinion Piece*: The Value of Publishing Negative Scientific Study Data. Toxicol Pathol 2015; 43:901-6. [PMID: 26269614 DOI: 10.1177/0192623315595884] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Historically it has been easier to publish positive scientific results than negative data not supporting the research hypothesis. This appears to be increasing, with fewer negative studies appearing in the literature across many disciplines. Failure to recognize the value of negative results has important implications for the toxicology community. Implications include perpetuating scientific fields based upon selective or occasionally erroneous, positive results. One example is decreased vaccination rates and increased measles infections that can lead to childhood mortality following one erroneous positive study linking vaccination to adverse effects despite multiple negative studies. Publication of negative data that challenges existing paradigms enhances progress by stopping further investment in scientifically barren topics, decreases the use of animals, and focuses research in more fruitful areas. The National Toxicology Program (NTP) publishes both positive and negative rodent data. Retrospective analysis of the NTP database has provided insights on the carcinogenic process and in the gradual acceptance of using fewer animals in safety studies. This article proposes that careful publication of both positive and negative data can enhance product safety assessment, add robustness to safety determinations in the regulatory decision-making process, and should be actively encouraged by those determining journal editorial policy.
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Affiliation(s)
| | | | | | - Sabine Francke
- U.S. Office of Facilities and Administrative Services/Center for Food Safety and Applied Nutrition/Food and Drug Administration, College Park, Maryland, USA
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37
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Kimura M, Abe H, Mizukami S, Tanaka T, Itahashi M, Onda N, Yoshida T, Shibutani M. Onset of hepatocarcinogen-specific cell proliferation and cell cycle aberration during the early stage of repeated hepatocarcinogen administration in rats. J Appl Toxicol 2015; 36:223-37. [DOI: 10.1002/jat.3163] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Revised: 03/08/2015] [Accepted: 03/17/2015] [Indexed: 01/26/2023]
Affiliation(s)
- Masayuki Kimura
- 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
| | - Hajime Abe
- 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
| | - Sayaka Mizukami
- 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
| | - Takeshi Tanaka
- 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
| | - Megu Itahashi
- 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
| | - Nobuhiko Onda
- Laboratory of Veterinary Pathology; Tokyo University of Agriculture and Technology; Fuchu-shi Tokyo Japan
| | - Toshinori Yoshida
- Laboratory of Veterinary Pathology; 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
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Ring M, Eskofier BM. Data mining in the U.S. National Toxicology Program (NTP) database reveals a potential bias regarding liver tumors in rodents irrespective of the test agent. PLoS One 2015; 10:e0116488. [PMID: 25658102 PMCID: PMC4319901 DOI: 10.1371/journal.pone.0116488] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 12/08/2014] [Indexed: 11/19/2022] Open
Abstract
Long-term studies in rodents are the benchmark method to assess carcinogenicity of single substances, mixtures, and multi-compounds. In such a study, mice and rats are exposed to a test agent at different dose levels for a period of two years and the incidence of neoplastic lesions is observed. However, this two-year study is also expensive, time-consuming, and burdensome to the experimental animals. Consequently, various alternatives have been proposed in the literature to assess carcinogenicity on basis of short-term studies. In this paper, we investigated if effects on the rodents' liver weight in short-term studies can be exploited to predict the incidence of liver tumors in long-term studies. A set of 138 paired short- and long-term studies was compiled from the database of the U.S. National Toxicology Program (NTP), more precisely, from (long-term) two-year carcinogenicity studies and their preceding (short-term) dose finding studies. In this set, data mining methods revealed patterns that can predict the incidence of liver tumors with accuracies of over 80%. However, the results simultaneously indicated a potential bias regarding liver tumors in two-year NTP studies. The incidence of liver tumors does not only depend on the test agent but also on other confounding factors in the study design, e.g., species, sex, type of substance. We recommend considering this bias if the hazard or risk of a test agent is assessed on basis of a NTP carcinogenicity study.
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Affiliation(s)
- Matthias Ring
- Digital Sports Group, Pattern Recognition Lab, Friedrich-Alexander-Universität, Erlangen-Nürnberg (FAU), Germany
- * E-mail:
| | - Bjoern M. Eskofier
- Digital Sports Group, Pattern Recognition Lab, Friedrich-Alexander-Universität, Erlangen-Nürnberg (FAU), Germany
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ToxDBScan: Large-scale similarity screening of toxicological databases for drug candidates. Int J Mol Sci 2014; 15:19037-55. [PMID: 25338045 PMCID: PMC4227259 DOI: 10.3390/ijms151019037] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 09/05/2014] [Accepted: 09/25/2014] [Indexed: 12/24/2022] Open
Abstract
We present a new tool for hepatocarcinogenicity evaluation of drug candidates in rodents. ToxDBScan is a web tool offering quick and easy similarity screening of new drug candidates against two large-scale public databases, which contain expression profiles for substances with known carcinogenic profiles: TG-GATEs and DrugMatrix. ToxDBScan uses a set similarity score that computes the putative similarity based on similar expression of genes to identify chemicals with similar genotoxic and hepatocarcinogenic potential. We propose using a discretized representation of expression profiles, which use only information on up- or down-regulation of genes as relevant features. Therefore, only the deregulated genes are required as input. ToxDBScan provides an extensive report on similar compounds, which includes additional information on compounds, differential genes and pathway enrichments. We evaluated ToxDBScan with expression data from 15 chemicals with known hepatocarcinogenic potential and observed a sensitivity of 88 Based on the identified chemicals, we achieved perfect classification of the independent test set. ToxDBScan is publicly available from the ZBIT Bioinformatics Toolbox.
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Gusenleitner D, Auerbach SS, Melia T, Gómez HF, Sherr DH, Monti S. Genomic models of short-term exposure accurately predict long-term chemical carcinogenicity and identify putative mechanisms of action. PLoS One 2014; 9:e102579. [PMID: 25058030 PMCID: PMC4109923 DOI: 10.1371/journal.pone.0102579] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Accepted: 06/20/2014] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Despite an overall decrease in incidence of and mortality from cancer, about 40% of Americans will be diagnosed with the disease in their lifetime, and around 20% will die of it. Current approaches to test carcinogenic chemicals adopt the 2-year rodent bioassay, which is costly and time-consuming. As a result, fewer than 2% of the chemicals on the market have actually been tested. However, evidence accumulated to date suggests that gene expression profiles from model organisms exposed to chemical compounds reflect underlying mechanisms of action, and that these toxicogenomic models could be used in the prediction of chemical carcinogenicity. RESULTS In this study, we used a rat-based microarray dataset from the NTP DrugMatrix Database to test the ability of toxicogenomics to model carcinogenicity. We analyzed 1,221 gene-expression profiles obtained from rats treated with 127 well-characterized compounds, including genotoxic and non-genotoxic carcinogens. We built a classifier that predicts a chemical's carcinogenic potential with an AUC of 0.78, and validated it on an independent dataset from the Japanese Toxicogenomics Project consisting of 2,065 profiles from 72 compounds. Finally, we identified differentially expressed genes associated with chemical carcinogenesis, and developed novel data-driven approaches for the molecular characterization of the response to chemical stressors. CONCLUSION Here, we validate a toxicogenomic approach to predict carcinogenicity and provide strong evidence that, with a larger set of compounds, we should be able to improve the sensitivity and specificity of the predictions. We found that the prediction of carcinogenicity is tissue-dependent and that the results also confirm and expand upon previous studies implicating DNA damage, the peroxisome proliferator-activated receptor, the aryl hydrocarbon receptor, and regenerative pathology in the response to carcinogen exposure.
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Affiliation(s)
- Daniel Gusenleitner
- Bioinformatics Program, Boston University, Boston, Massachusetts, United States of America
- Department of Computational Biomedicine, Boston University Medical Campus, Boston, Massachusetts, United States of America
| | - Scott S. Auerbach
- Biomolecular Screening Branch, Division of the National Toxicology Program at the National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, North Carolina, United States of America
| | - Tisha Melia
- Bioinformatics Program, Boston University, Boston, Massachusetts, United States of America
| | - Harold F. Gómez
- Bioinformatics Program, Boston University, Boston, Massachusetts, United States of America
| | - David H. Sherr
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts, United States of America
| | - Stefano Monti
- Bioinformatics Program, Boston University, Boston, Massachusetts, United States of America
- Department of Computational Biomedicine, Boston University Medical Campus, Boston, Massachusetts, United States of America
- * E-mail:
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Rider CV, Nyska A, Cora MC, Kissling GE, Smith C, Travlos GS, Hejtmancik MR, Fomby LM, Colleton CA, Ryan MJ, Kooistra L, Morrison JP, Chan PC. Toxicity and carcinogenicity studies of Ginkgo biloba extract in rat and mouse: liver, thyroid, and nose are targets. Toxicol Pathol 2014; 42:830-43. [PMID: 23960164 PMCID: PMC3929544 DOI: 10.1177/0192623313501235] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Ginkgo biloba extract (GBE) is a popular herbal supplement that is used to improve circulation and brain function. In spite of widespread human exposure to relatively high doses over potentially long periods of time, there is a paucity of data from animal studies regarding the toxicity and carcinogenicity associated with GBE. In order to fill this knowledge gap, 3-month and 2-year toxicity and carcinogenicity studies with GBE administered by oral gavage to B6C3F1/N mice and F344/N rats were performed as part of the National Toxicology Program's Dietary Supplements and Herbal Medicines Initiative. The targets of GBE treatment were the liver, thyroid, and nose. These targets were consistent across exposure period, sex, and species, albeit with varying degrees of effect observed among studies. Key findings included a notably high incidence of hepatoblastomas in male and female mice and evidence of carcinogenic potential in the thyroid gland of both mice and rats. Various nonneoplastic lesions were observed beyond control levels in the liver, thyroid gland, and nose of rats and mice administered GBE. Although these results cannot be directly extrapolated to humans, the findings fill an important data gap in assessing risk associated with GBE use.
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Affiliation(s)
- Cynthia V Rider
- National Institute of Environmental Health Sciences, Research Triangle Park, Durham, North Carolina, USA
| | - Abraham Nyska
- Integrated Laboratory Systems Incorporated, Research Triangle Park, Durham, North Carolina, USA
| | - Michelle C Cora
- National Institute of Environmental Health Sciences, Research Triangle Park, Durham, North Carolina, USA
| | - Grace E Kissling
- National Institute of Environmental Health Sciences, Research Triangle Park, Durham, North Carolina, USA
| | - Cynthia Smith
- National Institute of Environmental Health Sciences, Research Triangle Park, Durham, North Carolina, USA
| | - Gregory S Travlos
- National Institute of Environmental Health Sciences, Research Triangle Park, Durham, North Carolina, USA
| | | | | | | | | | - Linda Kooistra
- Charles River Laboratories, Pathology Associates, Durham, North Carolina, USA
| | - James P Morrison
- Charles River Laboratories, Pathology Associates, Durham, North Carolina, USA
| | - Po C Chan
- National Institute of Environmental Health Sciences, Research Triangle Park, Durham, North Carolina, USA
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Weinhouse C, Anderson OS, Bergin IL, Vandenbergh DJ, Gyekis JP, Dingman MA, Yang J, Dolinoy DC. Dose-dependent incidence of hepatic tumors in adult mice following perinatal exposure to bisphenol A. ENVIRONMENTAL HEALTH PERSPECTIVES 2014; 122:485-91. [PMID: 24487385 PMCID: PMC4014767 DOI: 10.1289/ehp.1307449] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 01/17/2014] [Indexed: 05/18/2023]
Abstract
BACKGROUND Bisphenol A (BPA) is a high production volume chemical with hormone-like properties that has been implicated as a potential carcinogen. Early-life exposure has been linked to increased risk for precancerous lesions in mammary and prostate glands and the uterus, but no prior study has shown a significant association between BPA exposure and cancer development. OBJECTIVE We explored the effects of BPA exposure during gestation and lactation on adult incidence of hepatic tumors in mice. METHODS Isogenic mice were perinatally exposed to BPA through maternal diets containing one of four environmentally relevant doses of BPA (0, 50 ng, 50 μg, or 50 mg per kilogram of diet), and we followed approximately one male and one female per litter until they were 10 months of age. Animals were tested for known risk factors for hepatocellular carcinoma, including bacterial and viral infections. RESULTS We found dose-dependent incidence of hepatic tumors in 10-month-old BPA-exposed mice. Of the offspring examined, 23% presented with hepatic tumors or preneoplastic lesions. We observed a statistically significant dose-response relationship, with an odds ratio for neoplastic and preneoplastic lesions of 7.23 (95% CI: 3.23, 16.17) for mice exposed to 50 mg BPA/kg diet compared with unexposed controls. Observed early disease onset, absence of bacterial or viral infection, and lack of characteristic sexual dimorphism in tumor incidence support a nonclassical etiology. CONCLUSIONS To our knowledge, this is the first report of a statistically significant association between BPA exposure and frank tumors in any organ. Our results link early-life exposure to BPA with the development of hepatic tumors in rodents, and have potential implications for human health and disease.
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Wood CE, Jokinen MP, Johnson CL, Olson GR, Hester S, George M, Chorley BN, Carswell G, Carter JH, Wood CR, Bhat VS, Corton JC, DeAngelo AB. Comparative time course profiles of phthalate stereoisomers in mice. Toxicol Sci 2014; 139:21-34. [PMID: 24496636 DOI: 10.1093/toxsci/kfu025] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
More efficient models are needed to assess potential carcinogenicity hazard of environmental chemicals based on early events in tumorigenesis. Here, we investigated time course profiles for key events in an established cancer mode of action. Using a case study approach, we evaluated two reference phthalates, di(2-ethylhexyl) phthalate (DEHP) and its stereoisomer di-n-octyl phthalate (DNOP), across the span of a two-year carcinogenicity bioassay. Male B6C3F1 mice received diets with no phthalate added (control), DEHP at 0.12, 0.60, or 1.20%, or DNOP at 0.10, 0.50, or 1.00% (n = 80-83/group) for up to 104 weeks with six interim evaluations starting at week 4. Mean phthalate doses were 139, 845, and 3147 mg/kg/day for DEHP and 113, 755, and 1281 mg/kg/day for DNOP groups, respectively. Incidence and number of hepatocellular tumors (adenoma and/or carcinoma) were greater at ≥ 60 weeks for all DEHP groups with time and dose trends, whereas DNOP had no significant effects. Key events supported a peroxisome proliferator-activated receptor alpha (PPARα) mode of action for DEHP, with secondary cytotoxicity at the high dose, whereas DNOP induced modest increases in PPARα activity without proliferative or cytotoxic effects. Threshold estimates for later tumorigenic effects were identified at week 4 for relative liver weight (+24%) and PPARα activity (+79%) relative to the control group. Benchmark doses (BMDs) for these measures at week 4 clearly distinguished DEHP and DNOP and showed strong concordance with values at later time points and tumorigenic BMDs. Other target sites included testis and kidney, which showed degenerative changes at higher doses of DEHP but not DNOP. Our results highlight marked differences in the chronic toxicity profiles of structurally similar phthalates and demonstrate quantitative relationships between early bioindicators and later tumor outcomes.
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Affiliation(s)
- Charles E Wood
- National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709
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Guan P, Olaharski A, Fielden M, Roome N, Dragan Y, Sina J. Biomarkers of carcinogenicity and their roles in drug discovery and development. Expert Rev Clin Pharmacol 2014; 1:759-71. [DOI: 10.1586/17512433.1.6.759] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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45
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Marone PA, Hall WC, Hayes AW. Reassessing the two-year rodent carcinogenicity bioassay: a review of the applicability to human risk and current perspectives. Regul Toxicol Pharmacol 2013; 68:108-18. [PMID: 24287155 DOI: 10.1016/j.yrtph.2013.11.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Revised: 11/15/2013] [Accepted: 11/17/2013] [Indexed: 12/16/2022]
Abstract
The 2-year rodent carcinogenicity test has been the regulatory standard for the prediction of human outcomes for exposure to industrial and agro-chemicals, food additives, pharmaceuticals and environmental pollutants for over 50 years. The extensive experience and data accumulated over that time has spurred a vigorous debate and assessment, particularly over the last 10 years, of the usefulness of this test in terms of cost and time for the information obtained. With renewed interest in the United States and globally, plus new regulations in the European Union, to reduce, refine and replace sentinel animals, this review offers the recommendation that reliance on information obtained from detailed shorter-term, 6 months rodent studies, combined with genotoxicity and chemical mode of action can realize effective prediction of human carcinogenicity instead of the classical two year rodent bioassay. The aim of carcinogenicity studies should not be on the length of time, and by obligation, number of animals expended but on the combined systemic pathophysiologic influence of a suspected chemical in determining disease. This perspective is in coordination with progressive regulatory standards and goals globally to utilize effectively resources of animal usage, time and cost for the goal of human disease predictability.
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Affiliation(s)
| | - William C Hall
- Hall Consulting, Inc., 110 Shady Brook Circle #300, St. Simons Island, GA 31522, USA.
| | - A Wallace Hayes
- Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115, USA.
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46
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Ament Z, Waterman CL, West JA, Waterfield C, Currie RA, Wright J, Griffin JL. A metabolomics investigation of non-genotoxic carcinogenicity in the rat. J Proteome Res 2013; 12:5775-90. [PMID: 24161236 DOI: 10.1021/pr4007766] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Non-genotoxic carcinogens (NGCs) promote tumor growth by altering gene expression, which ultimately leads to cancer without directly causing a change in DNA sequence. As a result NGCs are not detected in mutagenesis assays. While there are proposed biomarkers of carcinogenic potential, the definitive identification of non-genotoxic carcinogens still rests with the rat and mouse long-term bioassay. Such assays are expensive and time-consuming and require a large number of animals, and their relevance to human health risk assessments is debatable. Metabolomics and lipidomics in combination with pathology and clinical chemistry were used to profile perturbations produced by 10 compounds that represented a range of rat non-genotoxic hepatocarcinogens (NGC), non-genotoxic non-hepatocarcinogens (non-NGC), and a genotoxic hepatocarcinogen. Each compound was administered at its maximum tolerated dose level for 7, 28, and 91 days to male Fisher 344 rats. Changes in liver metabolite concentration differentiated the treated groups across different time points. The most significant differences were driven by pharmacological mode of action, specifically by the peroxisome proliferator activated receptor alpha (PPAR-α) agonists. Despite these dominant effects, good predictions could be made when differentiating NGCs from non-NGCs. Predictive ability measured by leave one out cross validation was 87% and 77% after 28 days of dosing for NGCs and non-NGCs, respectively. Among the discriminatory metabolites we identified free fatty acids, phospholipids, and triacylglycerols, as well as precursors of eicosanoid and the products of reactive oxygen species linked to processes of inflammation, proliferation, and oxidative stress. Thus, metabolic profiling is able to identify changes due to the pharmacological mode of action of xenobiotics and contribute to early screening for non-genotoxic potential.
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Affiliation(s)
- Zsuzsanna Ament
- Medical Research Council Human Nutrition Research (MRC HNR), Elsie Widdowson Laboratory , 120 Fulbourn Road, Cambridge CB1 9NL, U.K. , The Department of Biochemistry, University of Cambridge , 80 Tennis Court Road, Cambridge CB2 1GA, U.K. , and Cambridge Systems Biology Centre (CSBC), University of Cambridge , Cambridge CB2 1QR, U.K
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Yafune A, Taniai E, Morita R, Akane H, Kimura M, Mitsumori K, Shibutani M. Immunohistochemical cellular distribution of proteins related to M phase regulation in early proliferative lesions induced by tumor promotion in rat two-stage carcinogenesis models. ACTA ACUST UNITED AC 2013; 66:1-11. [PMID: 23890812 DOI: 10.1016/j.etp.2013.07.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 06/02/2013] [Accepted: 07/01/2013] [Indexed: 10/26/2022]
Abstract
We have previously reported that 28-day treatment with hepatocarcinogens increases liver cells expressing p21(Cip1), a G1/S checkpoint protein, and M phase proteins, i.e., nuclear Cdc2, Aurora B, phosphorylated-Histone H3 (p-Histone H3) and heterochromatin protein 1α (HP1α), in rats. To examine the roles of these markers in the early stages of carcinogenesis, we investigated their cellular distribution in several carcinogenic target organs using rat two-stage carcinogenesis models. Promoting agents targeting the liver (piperonyl butoxide and methapyrilene hydrochloride), thyroid (sulfadimethoxine), urinary bladder (phenylethyl isothiocyanate), and forestomach and glandular stomach (catechol) were administered to rats after initiation treatment for the liver with N-diethylnitrosamine, thyroid with N-bis(2-hydroxypropyl)nitrosamine, urinary bladder with N-butyl-N-(4-hydroxybutyl)nitrosamine, and forestomach and glandular stomach with N-methyl-N'-nitro-N-nitrosoguanidine. Numbers of cells positive for nuclear Cdc2, Aurora B, p-Histone H3 and HP1α increased within preneoplastic lesions as determined by glutathione S-transferase placental form in the liver or phosphorylated p44/42 mitogen-activated protein kinase in the thyroid, and hyperplastic lesions having no known preneoplastic markers in the urinary bladder, forestomach and glandular stomach. Immunoreactive cells for p21(Cip1) were decreased within thyroid preneoplastic lesions; however, they were increased within liver preneoplastic lesions and hyperplastic lesions in other organs. These results suggest that M phase disruption commonly occur during the formation of preneoplastic lesions and hyperplastic lesions. Differences in the expression patterns of p21(Cip1) between thyroid preneoplastic and proliferative lesions in other organs may reflect differences in cell cycle regulation involving G1/S checkpoint function between proliferative lesions in each organ.
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Affiliation(s)
- Atsunori Yafune
- Laboratory of Veterinary Pathology, 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
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LeBaron MJ, Geter DR, Rasoulpour RJ, Gollapudi BB, Thomas J, Murray J, Kan HL, Wood AJ, Elcombe C, Vardy A, McEwan J, Terry C, Billington R. An integrated approach for prospectively investigating a mode-of-action for rodent liver effects. Toxicol Appl Pharmacol 2013; 270:164-73. [DOI: 10.1016/j.taap.2013.04.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 03/28/2013] [Accepted: 04/01/2013] [Indexed: 12/26/2022]
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Yafune A, Taniai E, Morita R, Hayashi H, Suzuki K, Mitsumori K, Shibutani M. Aberrant activation of M phase proteins by cell proliferation-evoking carcinogens after 28-day administration in rats. Toxicol Lett 2013; 219:203-10. [DOI: 10.1016/j.toxlet.2013.03.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Revised: 03/12/2013] [Accepted: 03/15/2013] [Indexed: 12/30/2022]
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50
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Expression patterns of cell cycle proteins in the livers of rats treated with hepatocarcinogens for 28 days. Arch Toxicol 2013; 87:1141-53. [DOI: 10.1007/s00204-013-1011-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2012] [Accepted: 01/17/2013] [Indexed: 10/27/2022]
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