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Dos Santos Silva E, Matos MJ, Maistro EL. Evaluation of in vitro cytotoxic and genotoxic effects of the 3-(3,4-dihydroxyphenyl)-8-hydroxycoumarin. J Appl Toxicol 2023; 43:1488-1498. [PMID: 37118884 DOI: 10.1002/jat.4479] [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: 03/21/2023] [Revised: 04/12/2023] [Accepted: 04/23/2023] [Indexed: 04/30/2023]
Abstract
A wide variety of natural and synthetic coumarins present therapeutic potential. Therefore, the assessment of their safety for humans is essential. 3-(3,4-Dihydroxyphenyl)-8-hydroxycoumarin is a coumarin derivative with antioxidant properties, among other biological activities. The aim of this study is to evaluate the cytotoxic and genotoxic potential of this molecule on peripheral blood mononuclear cells (PBMC) and human hepatocellular carcinoma cells (HepG2/C3A). The results obtained for the cytotoxicity assays, evaluated by the trypan blue staining assay, using concentrations between 0.1 and 20 μg/mL, showed that there is no decrease in cell viability for both cell lines. The MTT assay showed a significant decrease in the viability of HepG2/C3A cells at the highest concentrations tested, after 48 h, for all the tested concentrations, after 72 h of exposure. Regarding the genotoxic assays, the data obtained by the comet assay and the micronucleus test, up to the tested concentration of 10 μg/mL, do not show significant DNA damage and/or chromosomal mutations, for both cell lines. However, at the highest tested concentration of 20 μg/mL, a small but significant genotoxic effect was observed in PBMC. In view of the observed results, it can be concluded that the 3-(3,4-dihydroxyphenyl)-8-hydroxycoumarin, up to a concentration of 10 μg/mL, does not present genotoxic effects in human cells with and without liver enzymes metabolism. Additional studies with higher concentrations of this molecule need to be performed to address its complete biosafety.
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Affiliation(s)
| | - Maria João Matos
- Departamento de Química Orgánica, Facultade de Farmacia, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Edson Luis Maistro
- Faculdade de Medicina de Marilia, FAMEMA, Marília, Brazil
- Faculdade de Filosofia e Ciências, Departamento de Fonoaudiologia, Universidade Estadual Paulista-UNESP, Marília, Brazil
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2
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de Quadros APO, Baraldi IB, Petreanu M, Niero R, Mantovani MS, De Mascarenhas Gaivão IO, Maistro EL. Cytogenotoxic evaluations of leaves and stems extracts of Rubus rosifolius in primary metabolically noncompetent cells. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2023; 86:361-371. [PMID: 37096566 DOI: 10.1080/15287394.2023.2203190] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Plants with medicinal potential may also produce adverse effects in humans. This seems to be the case for the species Rubus rosifolius, where preliminary studies demonstrated genotoxic effects attributed to extracts obtained from leaves and stems of this plant using on HepG2/C3A human hepatoma cells as a model. Considering the beneficial properties of this plant as an antidiarrheal, analgesic, antimicrobial, and antihypertensive and its effects in the treatment of gastrointestinal diseases, the present study was developed with the aim of determining the cytotoxic and genotoxic potential of extracts of leaves and stems of R. rosifolius in primary without metabolic competence in human peripheral blood mononuclear cells (PBMC). Cell viability analyses at concentrations of between 0.01 and 100 µg/ml of both extracts did not markedly affect cell viability. In contrast, assessment of the genotoxic potential using the comet assay demonstrated significant damage to DNA within PBMC from a concentration of 10 µg/ml in the stem extract, and a clastogenic/aneugenic response without cytokinesis-block proliferation index (CBPI) alterations at concentrations of 10, 20, or 100 µg/ml for both extracts. Under our experimental conditions, the data obtained demonstrated genotoxic and mutagenic effects attributed to extracts from leaves and stems of R. rosifolius in cells in the absence of hepatic metabolism.
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Affiliation(s)
- Ana Paula Oliveira de Quadros
- Post-Graduate Program on General and Applied Biology, São Paulo State University - UNESP - Biosciences Institute, Botucatu, SP, Brazil
| | - Isabel Bragança Baraldi
- Speech and Hearing Therapy Department, São Paulo State University - UNESP - Faculty of Philosophy and Sciences, Marília, SP, Brazil
| | - Marcel Petreanu
- Department of Biological Sciences, Vale do Itajaí University (UNIVALI), Itajaí, SC, Brazil
| | - Rivaldo Niero
- Department of Biological Sciences, Vale do Itajaí University (UNIVALI), Itajaí, SC, Brazil
| | | | | | - Edson Luis Maistro
- Post-Graduate Program on General and Applied Biology, São Paulo State University - UNESP - Biosciences Institute, Botucatu, SP, Brazil
- Speech and Hearing Therapy Department, São Paulo State University - UNESP - Faculty of Philosophy and Sciences, Marília, SP, Brazil
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3
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Raman MD, Abd Rahman N, Elumalai S, Murugaiyah V, Ong MT. Hevea brasiliensis latex dialysed C-serum precipitate subfraction exerts a negligible level of genotoxicity in the Ames test, mouse lymphoma assay and micronucleus assay. J RUBBER RES 2023; 26:139-153. [DOI: 10.1007/s42464-023-00201-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 04/13/2023] [Indexed: 09/02/2023]
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4
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Seo JE, Li X, Le Y, Mei N, Zhou T, Guo X. High-throughput micronucleus assay using three-dimensional HepaRG spheroids for in vitro genotoxicity testing. Arch Toxicol 2023; 97:1163-1175. [PMID: 36847820 DOI: 10.1007/s00204-023-03461-z] [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: 12/29/2022] [Accepted: 02/16/2023] [Indexed: 03/01/2023]
Abstract
The in vitro micronucleus (MN) assay is a component of most test batteries used in assessing potential genotoxicity. Our previous study adapted metabolically competent HepaRG cells to the high-throughput (HT) flow-cytometry-based MN assay for genotoxicity assessment (Guo et al. in J Toxicol Environ Health A 83:702-717, 2020b, https://doi.org/10.1080/15287394.2020.1822972 ). We also demonstrated that, compared to HepaRG cells grown as two-dimensional (2D) cultures, 3D HepaRG spheroids have increased metabolic capacity and improved sensitivity in detecting DNA damage induced by genotoxicants using the comet assay (Seo et al. in ALTEX 39:583-604, 2022, https://doi.org/10.14573/altex.22011212022 ). In the present study, we have compared the performance of the HT flow-cytometry-based MN assay in HepaRG spheroids and 2D HepaRG cells by testing 34 compounds, including 19 genotoxicants or carcinogens and 15 compounds that show different genotoxic responses in vitro and in vivo. 2D HepaRG cells and spheroids were exposed to the test compounds for 24 h, followed by an additional 3- or 6-day incubation with human epidermal growth factor to stimulate cell division. The results demonstrated that HepaRG spheroids showed generally higher sensitivity in detecting several indirect-acting genotoxicants (require metabolic activation) compared to 2D cultures, with 7,12-dimethylbenzanthracene and N-nitrosodimethylamine inducing higher % MN formation along with having significantly lower benchmark dose values for MN induction in 3D spheroids. These data suggest that 3D HepaRG spheroids can be adapted to the HT flow-cytometry-based MN assay for genotoxicity testing. Our findings also indicate that integration of the MN and comet assays improved the sensitivity for detecting genotoxicants that require metabolic activation. These results suggest that HepaRG spheroids may contribute to New Approach Methodologies for genotoxicity assessment.
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Affiliation(s)
- Ji-Eun Seo
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, 72079, USA.
| | - Xilin Li
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Yuan Le
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Nan Mei
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Tong Zhou
- Center for Veterinary Medicine, U.S. Food and Drug Administration, Rockville, MD, 20855, USA
| | - Xiaoqing Guo
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, 72079, USA.
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5
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Sanders J, Thienpont A, Anthonissen R, Vanhaecke T, Mertens B. Impact of experimental design factors on the potency of genotoxicants in in vitro tests. Mutagenesis 2022; 37:248-258. [PMID: 36448879 DOI: 10.1093/mutage/geac025] [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: 07/28/2022] [Accepted: 11/14/2022] [Indexed: 12/02/2022] Open
Abstract
Previous studies have shown that differences in experimental design factors may alter the potency of genotoxic compounds in in vitro genotoxicity tests. Most of these studies used traditional statistical methods based on the lowest observed genotoxic effect levels, whereas more appropriate methods, such as the benchmark dose (BMD) approach, are now available to compare genotoxic potencies under different test conditions. We therefore investigated the influence of two parameters, i.e. cell type and exposure duration, on the potencies of two known genotoxicants [aflatoxin B1 and ethyl methanesulfonate (EMS)] in the in vitro micronucleus (MN) assay and comet assay (CA). Both compounds were tested in the two assays using two cell types (i.e. CHO-K1 and TK6 cells). To evaluate the effect of exposure duration, the genotoxicity of EMS was assessed after 3 and 24 h of exposure. Results were analyzed using the BMD covariate approach, also referred to as BMD potency ranking, and the outcome was compared with that of more traditional statistical methods based on lowest observed genotoxic effect levels. When comparing the in vitro MN results obtained in both cell lines with the BMD covariate approach, a difference in potency was detected only when EMS exposures were conducted for 24 h, with TK6 cells being more sensitive. No difference was observed in the potency of both EMS and aflatoxin B1 in the in vitro CA using both cell lines. In contrast, EMS was more potent after 24 h exposure compared with a 3 h exposure under all tested conditions, i.e. in the in vitro MN assay and CA in both cell lines. Importantly, for several of the investigated factors, the BMD covariate method could not be used to confirm the differences in potencies detected with the traditional statistical methods, thus highlighting the need to evaluate the impact of experimental design factors with adequate approaches.
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Affiliation(s)
- Julie Sanders
- Department of Chemical and Physical Health Risks, Sciensano, Brussels, Belgium.,Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Anouck Thienpont
- Department of Chemical and Physical Health Risks, Sciensano, Brussels, Belgium.,Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Roel Anthonissen
- Department of Chemical and Physical Health Risks, Sciensano, Brussels, Belgium
| | - Tamara Vanhaecke
- Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Birgit Mertens
- Department of Chemical and Physical Health Risks, Sciensano, Brussels, Belgium
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Allemang A, Lester C, Roth T, Pfuhler S, Peuschel H, Kosemund K, Mahony C, Bergeland T, O'Keeffe L. Assessing the genotoxicity and carcinogenicity of 2-chloroethanol through structure activity relationships and in vitro testing approaches. Food Chem Toxicol 2022; 168:113290. [PMID: 35863484 DOI: 10.1016/j.fct.2022.113290] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 06/16/2022] [Accepted: 07/08/2022] [Indexed: 11/25/2022]
Abstract
The detection of 2-chloroethanol in foods generally follows an assumption that the pesticide ethylene oxide has been used at some stage in the supply chain. In this situation the Pesticide Residues in Food Regulation (EC) 396/2005 requires 2-chloroethanol to be assessed as if equivalent to ethylene oxide, which has been classified as a genotoxic carcinogen. This review investigated whether this is an appropriate risk assessment approach for 2-chloroethanol. This involved an assessment of existing genotoxicity and carcinogenicity data, application of Structure Activity Based Read Across for carcinogenicity assessment, biological reactivity in the ToxTracker assay and micronuclei formation in HepaRG cells. Although we identified there is an absence of a standard oral bioassay for 2-chloroethanol, carcinogenicity weight-of-evidence assessment along with data on relevant structural analogues do not show evidence for carcinogenicity for 2-chloroethanol. The absence of genotoxicity was demonstrated for 2-chloroethanol and suitable analogues. In contrast, ethylene oxide showed reactivity towards markers indicative of direct DNA damage which is consistent with what is known about its mode-of-action. These data facilitate the understanding of 2-chloroethanol and given that it is not a genotoxic carcinogen suggest it must be assessed relative to non-cancer endpoints and a health protective Reference Dose should be established on that basis.
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Affiliation(s)
| | - Cathy Lester
- The Procter & Gamble Company, Cincinnati, OH, USA
| | - Thomas Roth
- SCC Scientific Consulting Company GmbH, Am Grenzgraben 11, 55545, Bad Kreuznach, Germany
| | | | - Henrike Peuschel
- SCC Scientific Consulting Company GmbH, Am Grenzgraben 11, 55545, Bad Kreuznach, Germany
| | - Kirstin Kosemund
- Procter & Gamble Service GmbH, Sulzbacher Str. 40, 65824, Schwalbach am Taunus, Germany
| | | | | | - Lara O'Keeffe
- The Procter & Gamble Company, Reading, Berkshire, UK.
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7
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Akh LA, Ishak MO, Harris JF, Glaros TG, Sasiene ZJ, Mach PM, Lilley LM, McBride EM. -Omics potential of in vitro skin models for radiation exposure. Cell Mol Life Sci 2022; 79:390. [PMID: 35776214 PMCID: PMC11073334 DOI: 10.1007/s00018-022-04394-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/12/2022] [Accepted: 05/24/2022] [Indexed: 11/12/2022]
Abstract
There is a growing need to uncover biomarkers of ionizing radiation exposure that leads to a better understanding of how exposures take place, including dose type, rate, and time since exposure. As one of the first organs to be exposed to external sources of ionizing radiation, skin is uniquely positioned in terms of model systems for radiation exposure study. The simultaneous evolution of both MS-based -omics studies, as well as in vitro 3D skin models, has created the ability to develop a far more holistic understanding of how ionizing radiation affects the many interconnected biomolecular processes that occur in human skin. However, there are a limited number of studies describing the biomolecular consequences of low-dose ionizing radiation to the skin. This review will seek to explore the current state-of-the-art technology in terms of in vitro 3D skin models, as well as track the trajectory of MS-based -omics techniques and their application to ionizing radiation research, specifically, the search for biomarkers within the low-dose range.
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Affiliation(s)
- Leyla A Akh
- Biosecurity and Public Health Group, Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Mohammad O Ishak
- Biosecurity and Public Health Group, Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Jennifer F Harris
- Biosecurity and Public Health Group, Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Trevor G Glaros
- Bioenergy and Biome Sciences Group, Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Zachary J Sasiene
- Bioenergy and Biome Sciences Group, Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Phillip M Mach
- Bioenergy and Biome Sciences Group, Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Laura M Lilley
- Physical Chemistry and Applied Spectroscopy Group, Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
| | - Ethan M McBride
- Bioenergy and Biome Sciences Group, Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
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Thakkar Y, Moustakas H, Aardema M, Roy S, Pfuhler S, Api AM. Use of the EpiDerm TM 3D reconstructed skin micronucleus assay for fragrance materials. Mutagenesis 2021; 37:89-111. [PMID: 34850913 PMCID: PMC9071073 DOI: 10.1093/mutage/geab040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 11/17/2021] [Indexed: 11/15/2022] Open
Abstract
In order to evaluate the utility of the 3D reconstructed skin micronucleus assay (3DRSMN) to assess clastogenic/aneugenic potential of the fragrance chemicals, a set of 22 fragrance materials were evaluated in 3DRSMN assay. These materials evaluated were also evaluated in an in vitro as well as in vivo micronucleus assay, conducted as per Organisation for Economic Co-operation and Development guidelines. The results of the RSMN assay were in 100% agreement with the in vivo micronucleus assay results. From this dataset, 18 materials were positive in an in vitro micronucleus assay but were negative in an in vivo micronucleus assay. All these 18 materials were also concluded to be negative in 3DRSMN assay, stressing the importance of the assay to help minimize misleading positive outcomes from the in vitro assay. Since the highest exposure for fragrances is through the dermal route, the RSMN assay fits the applicability domain for testing. Thus, RSMN assay is an important alternative to animal testing for characterization of the genotoxicity potential of fragrance materials.
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Affiliation(s)
- Yax Thakkar
- Research Institute for Fragrance Materials, Inc. 50 Tice Blvd. Woodcliff Lake, NJ
| | - Holger Moustakas
- Research Institute for Fragrance Materials, Inc. 50 Tice Blvd. Woodcliff Lake, NJ
| | - Marilyn Aardema
- Marilyn Aardema Consulting LLC, 5315 Oakbrook Dr, Fairfield, OH 45014, USA
| | - Shambhu Roy
- Millipore Sigma, 14920 Broschart Road, Rockville, MD 20850, USA
| | - Stefan Pfuhler
- The Procter & Gamble Company, Mason Business Centre, Mason, Ohio
| | - Anne Marie Api
- Research Institute for Fragrance Materials, Inc. 50 Tice Blvd. Woodcliff Lake, NJ
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9
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Pfuhler S, Downs TR, Hewitt NJ, Hoffmann S, Mun GC, Ouedraogo G, Roy S, Curren RD, Aardema MJ. Validation of the 3D reconstructed human skin micronucleus (RSMN) assay: an animal-free alternative for following-up positive results from standard in vitro genotoxicity assays. Mutagenesis 2021; 36:1-17. [PMID: 33544138 PMCID: PMC8081377 DOI: 10.1093/mutage/geaa035] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 11/25/2020] [Indexed: 11/13/2022] Open
Abstract
In vitro test batteries have become the standard approach to determine the genotoxic potential of substances of interest across industry sectors. While useful for hazard identification, standard in vitro genotoxicity assays in 2D cell cultures have limited capability to predict in vivo outcomes and may trigger unnecessary follow-up animal studies or the loss of promising substances where animal tests are prohibited or not desired. To address this problem, a team of regulatory, academia and industry scientists was established to develop and validate 3D in vitro human skin-based genotoxicity assays for use in testing substances with primarily topical exposure. Validation of the reconstructed human skin micronucleus (RSMN) assay in MatTek Epi-200™ skin models involved testing 43 coded chemicals selected by independent experts, in four US/European laboratories. The results were analysed by an independent statistician according to predefined criteria. The RSMN assay showed a reproducibly low background micronucleus frequency and exhibited sufficient capacity to metabolise pro-mutagens. The overall RSMN accuracy when compared to in vivo genotoxicity outcomes was 80%, with a sensitivity of 75% and a specificity of 84%, and the between- and within-laboratory reproducibility was 77 and 84%, respectively. A protocol involving a 72-h exposure showed increased sensitivity in detecting true positive chemicals compared to a 48-h exposure. An analysis of a test strategy using the RSMN assay as a follow-up test for substances positive in standard in vitro clastogenicity/aneugenicity assays and a reconstructed skin Comet assay for substances with positive results in standard gene mutation assays results in a sensitivity of 89%. Based on these results, the RSMN assay is considered sufficiently validated to establish it as a ‘tier 2’ assay for dermally exposed compounds and was recently accepted into the OECD’s test guideline development program.
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Affiliation(s)
| | | | | | | | - Greg C Mun
- Institute for In Vitro Sciences, Inc., Gaithersburg, MD, USA
| | | | | | - Rodger D Curren
- Institute for In Vitro Sciences, Inc., Gaithersburg, MD, USA
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10
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Downs TR, Arlt VM, Barnett BC, Posgai R, Pfuhler S. Effect of 2-acetylaminofluorene and its genotoxic metabolites on DNA adduct formation and DNA damage in 3D reconstructed human skin tissue models. Mutagenesis 2021; 36:63-74. [PMID: 31816077 PMCID: PMC8081378 DOI: 10.1093/mutage/gez044] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 11/15/2019] [Indexed: 12/14/2022] Open
Abstract
In vitro genotoxicity assays utilising human skin models are becoming important tools for the safety assessment of chemicals whose primary exposure is via the dermal route. In order to explore metabolic competency and inducibility of CYP450 activating enzymes, 3D reconstructed human skin tissues were topically treated with 2-acetylaminofluorene (2-AAF) and its genotoxic metabolites, N-hydroxy-2-acetylaminofluorene (N-OH-2-AAF) and N-hydroxy-2-aminofluorene (N-OH-2-AF), which primarily cause DNA damage by forming DNA adducts. 2-AAF did not increase DNA damage measured in the reconstructed skin micronucleus (RSMN) assay when administered in multiple applications at 24 h intervals but was detected in the skin comet assay in the presence of the DNA polymerase inhibitor aphidicolin (APC). Similarly, no increase was found with N-OH-2-AAF in the RSMN assay after multiple treatments whereas a single 3 h exposure to N-OH-2-AAF caused a large dose-related increase in the skin comet assay. A significant increase in the RSMN assay was only obtained with the highly reactive N-OH-2-AF metabolite after multiple treatments over 72 h, whereas N-OH-2-AF caused a strong increase after a single 3 h exposure in the skin comet assay. In support of these results, DNA adduct formation, measured by the 32P-postlabelling assay, was examined. Adduct levels after 2-AAF treatment for 3 h were minimal but increased >10-fold after multiple exposures over 48 h, suggesting that enzyme(s) that metabolise 2-AAF are induced in the skin models. As expected, a single 3 h exposure to N-OH-2-AAF and N-OH-2-AF resulted in adduct levels that were at least 10-fold greater than those after multiple exposures to 2-AAF despite ~100-fold lower tested concentrations. Our results demonstrate that DNA damage caused by 2-AAF metabolites is more efficiently detected in the skin comet assay than the RSMN assay and after multiple exposures and enzyme induction, 2-AAF-induced DNA damage can be detected in the APC-modified comet assay.
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Affiliation(s)
| | - Volker M Arlt
- Department of Analytical, Environmental and Forensic Sciences, King’s College London, London, UK
- NIHR Health Protection Research Unit in Health Impact of Environmental Hazards, King’s College London in Partnership with Public Health England and Imperial College London, London, UK
| | | | | | - Stefan Pfuhler
- Procter & Gamble, Mason, OH, USA
- To whom correspondence should be addressed. Tel: +1 513 622 1163; E-mail:
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11
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Maul K, Fieblinger D, Heppenheimer A, Kreutz J, Liebsch M, Luch A, Pirow R, Poth A, Strauch P, Dony E, Schulz M, Wolf T, Reisinger K. Validation of the hen's egg test for micronucleus induction (HETMN): Detailed protocol including scoring atlas, historical control data and statistical analysis. Mutagenesis 2021; 37:76-88. [PMID: 34313790 PMCID: PMC9071076 DOI: 10.1093/mutage/geab026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 08/03/2021] [Indexed: 11/14/2022] Open
Abstract
A validation exercise of the hen's egg test for micronucleus induction (HET-MN) was finalised with a very good predictivity based on the analysis of micronuclei in peripheral erythrocytes of fertilised chicken eggs [1]. For transparency reasons this complementary publication provides further details on the assay especially as this was the first validation study in the field of genotoxicity testing involving the use of chicken eggs. Thus, the experimental protocol is described in detail and is complemented by a scoring atlas for microscopic analysis of blood cells. In addition, general characteristics of the test system, which is able to mirror the systemic availability of test compounds, are delineated: the test compound passes the egg membrane and is taken up by the blood vessels of the underlying chorioallantoic membrane. Subsequently, it is distributed by the circulating blood, metabolised by the developing liver and the yolk sac membrane, and finally excreted into the allantois, a bladder equivalent. In specific, the suitability of the test system for genotoxicity testing is shown by, inter alia, a low background DNA damage in a comprehensive historical control database. In addition, the state-of-the-art statistical method used to evaluate obtained data is delineated. It combines laboratory-specific effect threshold with the Umbrella-Williams test a statistical model also of interest for other genotoxicity test methods.
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Affiliation(s)
- K Maul
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Berlin, Germany
| | - D Fieblinger
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Berlin, Germany
| | - A Heppenheimer
- ICCR-Roßdorf GmbH (former: Harlan Cytotest Cell Research, Envigo CRS), Roßdorf, Germany
| | - J Kreutz
- Henkel AG & Co KGaA, Duesseldorf, Germany
| | - M Liebsch
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Berlin, Germany
| | - A Luch
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Berlin, Germany
| | - R Pirow
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Berlin, Germany
| | - A Poth
- ICCR-Roßdorf GmbH (former: Harlan Cytotest Cell Research, Envigo CRS), Roßdorf, Germany
| | - P Strauch
- ICCR-Roßdorf GmbH (former: Harlan Cytotest Cell Research, Envigo CRS), Roßdorf, Germany
| | - E Dony
- ICCR-Roßdorf GmbH (former: Harlan Cytotest Cell Research, Envigo CRS), Roßdorf, Germany
| | - M Schulz
- ICCR-Roßdorf GmbH (former: Harlan Cytotest Cell Research, Envigo CRS), Roßdorf, Germany
| | - T Wolf
- University of Osnabrueck, Osnabrueck, Germany
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Mišík M, Nersesyan A, Kment M, Ernst B, Setayesh T, Ferk F, Holzmann K, Krupitza G, Knasmueller S. Micronucleus assays with the human derived liver cell line (Huh6): A promising approach to reduce the use of laboratory animals in genetic toxicology. Food Chem Toxicol 2021; 154:112355. [PMID: 34147571 DOI: 10.1016/j.fct.2021.112355] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 06/11/2021] [Accepted: 06/13/2021] [Indexed: 01/22/2023]
Abstract
The inadequate representation of enzymes which catalyze the activation/detoxification of xenobiotics in cells that are currently used in genotoxicity testing of chemicals leads to a high number of false positive results and the number of follow up studies with rodents could be reduced by use of more reliable in vitro models. We found earlier that several xenobiotic drug metabolizing enzymes are represented in the human derived liver cell line Huh6 and developed a protocol for micronucleus (MN) experiments which is in agreement with the current OECD guideline. This protocol was used to test 23 genotoxic and non-genotoxic reference chemicals; based on these results and of earlier findings (with 9 chemicals) we calculated the predictive value of the assay for the detection of genotoxic carcinogens. We found a sensitivity of 80% and a specificity of 94% for a total number of 32 chemicals; comparisons with results obtained with other in vitro assays show that the validity of MN tests with Huh6 is higher as that of other experimental models. These results are promising and indicate that the use of Huh6 cells in genetic toxicology may contribute to the reduction of the use of laboratory rodents; further experimental work to confirm this assumption is warranted.
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Affiliation(s)
- Miroslav Mišík
- Institute of Cancer Research, Medical University of Vienna, Vienna, Austria
| | - Armen Nersesyan
- Institute of Cancer Research, Medical University of Vienna, Vienna, Austria
| | - Michael Kment
- Institute of Cancer Research, Medical University of Vienna, Vienna, Austria
| | - Benjamin Ernst
- Institute of Cancer Research, Medical University of Vienna, Vienna, Austria
| | - Tahereh Setayesh
- Institute of Cancer Research, Medical University of Vienna, Vienna, Austria
| | - Franziska Ferk
- Institute of Cancer Research, Medical University of Vienna, Vienna, Austria
| | - Klaus Holzmann
- Institute of Cancer Research, Medical University of Vienna, Vienna, Austria
| | - Georg Krupitza
- Department of Pathology, Medical University of Vienna, Vienna, 1090, Austria
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13
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Pistollato F, Madia F, Corvi R, Munn S, Grignard E, Paini A, Worth A, Bal-Price A, Prieto P, Casati S, Berggren E, Bopp SK, Zuang V. Current EU regulatory requirements for the assessment of chemicals and cosmetic products: challenges and opportunities for introducing new approach methodologies. Arch Toxicol 2021; 95:1867-1897. [PMID: 33851225 PMCID: PMC8166712 DOI: 10.1007/s00204-021-03034-y] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 03/18/2021] [Indexed: 12/28/2022]
Abstract
The EU Directive 2010/63/EU on the protection of animals used for scientific purposes and other EU regulations, such as REACH and the Cosmetic Products Regulation advocate for a change in the way toxicity testing is conducted. Whilst the Cosmetic Products Regulation bans animal testing altogether, REACH aims for a progressive shift from in vivo testing towards quantitative in vitro and computational approaches. Several endpoints can already be addressed using non-animal approaches including skin corrosion and irritation, serious eye damage and irritation, skin sensitisation, and mutagenicity and genotoxicity. However, for systemic effects such as acute toxicity, repeated dose toxicity and reproductive and developmental toxicity, evaluation of chemicals under REACH still heavily relies on animal tests. Here we summarise current EU regulatory requirements for the human health assessment of chemicals under REACH and the Cosmetic Products Regulation, considering the more critical endpoints and identifying the main challenges in introducing alternative methods into regulatory testing practice. This supports a recent initiative taken by the International Cooperation on Alternative Test Methods (ICATM) to summarise current regulatory requirements specific for the assessment of chemicals and cosmetic products for several human health-related endpoints, with the aim of comparing different jurisdictions and coordinating the promotion and ultimately the implementation of non-animal approaches worldwide. Recent initiatives undertaken at European level to promote the 3Rs and the use of alternative methods in current regulatory practice are also discussed.
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Affiliation(s)
- Francesca Pistollato
- Directorate F-Health, Consumers and Reference Materials, Unit F3 Chemicals Safety and Alternative Methods, European Commission, Joint Research Centre (JRC), Via E. Fermi, 2749. TP126, 21027, Ispra, VA, Italy
| | - Federica Madia
- Directorate F-Health, Consumers and Reference Materials, Unit F3 Chemicals Safety and Alternative Methods, European Commission, Joint Research Centre (JRC), Via E. Fermi, 2749. TP126, 21027, Ispra, VA, Italy
| | - Raffaella Corvi
- Directorate F-Health, Consumers and Reference Materials, Unit F3 Chemicals Safety and Alternative Methods, European Commission, Joint Research Centre (JRC), Via E. Fermi, 2749. TP126, 21027, Ispra, VA, Italy
| | - Sharon Munn
- Directorate F-Health, Consumers and Reference Materials, Unit F3 Chemicals Safety and Alternative Methods, European Commission, Joint Research Centre (JRC), Via E. Fermi, 2749. TP126, 21027, Ispra, VA, Italy
| | - Elise Grignard
- Directorate F-Health, Consumers and Reference Materials, Unit F3 Chemicals Safety and Alternative Methods, European Commission, Joint Research Centre (JRC), Via E. Fermi, 2749. TP126, 21027, Ispra, VA, Italy
| | - Alicia Paini
- Directorate F-Health, Consumers and Reference Materials, Unit F3 Chemicals Safety and Alternative Methods, European Commission, Joint Research Centre (JRC), Via E. Fermi, 2749. TP126, 21027, Ispra, VA, Italy
| | - Andrew Worth
- Directorate F-Health, Consumers and Reference Materials, Unit F3 Chemicals Safety and Alternative Methods, European Commission, Joint Research Centre (JRC), Via E. Fermi, 2749. TP126, 21027, Ispra, VA, Italy
| | - Anna Bal-Price
- Directorate F-Health, Consumers and Reference Materials, Unit F3 Chemicals Safety and Alternative Methods, European Commission, Joint Research Centre (JRC), Via E. Fermi, 2749. TP126, 21027, Ispra, VA, Italy
| | - Pilar Prieto
- Directorate F-Health, Consumers and Reference Materials, Unit F3 Chemicals Safety and Alternative Methods, European Commission, Joint Research Centre (JRC), Via E. Fermi, 2749. TP126, 21027, Ispra, VA, Italy
| | - Silvia Casati
- Directorate F-Health, Consumers and Reference Materials, Unit F3 Chemicals Safety and Alternative Methods, European Commission, Joint Research Centre (JRC), Via E. Fermi, 2749. TP126, 21027, Ispra, VA, Italy
| | - Elisabet Berggren
- Directorate F-Health, Consumers and Reference Materials, Unit F3 Chemicals Safety and Alternative Methods, European Commission, Joint Research Centre (JRC), Via E. Fermi, 2749. TP126, 21027, Ispra, VA, Italy
| | - Stephanie K Bopp
- Directorate F-Health, Consumers and Reference Materials, Unit F3 Chemicals Safety and Alternative Methods, European Commission, Joint Research Centre (JRC), Via E. Fermi, 2749. TP126, 21027, Ispra, VA, Italy
| | - Valérie Zuang
- Directorate F-Health, Consumers and Reference Materials, Unit F3 Chemicals Safety and Alternative Methods, European Commission, Joint Research Centre (JRC), Via E. Fermi, 2749. TP126, 21027, Ispra, VA, Italy.
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14
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Pfuhler S, Pirow R, Downs TR, Haase A, Hewitt N, Luch A, Merkel M, Petrick C, Said A, Schäfer-Korting M, Reisinger K. Validation of the 3D reconstructed human skin Comet assay, an animal-free alternative for following-up positive results from standard in vitro genotoxicity assays. Mutagenesis 2021; 36:19-35. [PMID: 32152633 PMCID: PMC8081376 DOI: 10.1093/mutage/geaa009] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 02/03/2020] [Indexed: 02/06/2023] Open
Abstract
As part of the safety assessment process, all industrial sectors employ genotoxicity test batteries, starting with well-established in vitro assays. However, these batteries have limited predictive capacity for the in vivo situation, which may result in unnecessary follow-up in vivo testing or the loss of promising substances where animal tests are prohibited or not desired. To address this, a project involving regulators, academia and industry was established to develop and validate in vitro human skin-based genotoxicity assays for topically exposed substances, such as cosmetics ingredients. Here, we describe the validation of the 3D reconstructed skin (RS) Comet assay. In this multicenter study, chemicals were applied topically three times to the skin over 48 h. Isolated keratinocytes and fibroblasts were transferred to slides before electrophoresis and the resulting comet formation was recorded as % tail DNA. Before decoding, results of the validation exercise for 32 substances were evaluated by an independent statistician. There was a high predictive capacity of this assay when compared to in vivo outcomes, with a sensitivity of 77 (80)%, a specificity of 88 (97)% and an overall accuracy of 83 (92)%. The numbers reflect the calls of the performing laboratories in the coded phase, whereas those in parenthesis reflect calls according to the agreed evaluation criteria. Intra- and inter-laboratory reproducibility was also very good, with a concordance of 93 and 88%, respectively. These results generated with the Phenion® Full-Thickness skin model demonstrate its suitability for this assay, with reproducibly low background DNA damage and sufficient metabolic capacity to activate pro-mutagens. The validation outcome supports the use of the RS Comet assay to follow up positive results from standard in vitro genotoxicity assays when the expected route of exposure is dermal. Based on the available data, the assay was accepted recently into the OECD test guideline development program.
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Affiliation(s)
| | - Ralph Pirow
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Berlin, Germany
| | | | - Andrea Haase
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Berlin, Germany
| | | | - Andreas Luch
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Berlin, Germany
| | | | | | - André Said
- German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Berlin, Germany
- Freie Universität Berlin, Institute for Pharmacy (Pharmacology and Toxicology), Berlin, Germany
| | - Monika Schäfer-Korting
- Freie Universität Berlin, Institute for Pharmacy (Pharmacology and Toxicology), Berlin, Germany
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15
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Thá EL, Matos M, Avelino F, Lomonaco D, Rodrigues-Souza I, Gagosian VSC, Cestari MM, Magalhães WLE, Leme DM. Safety aspects of kraft lignin fractions: Discussions on the in chemico antioxidant activity and the induction of oxidative stress on a cell-based in vitro model. Int J Biol Macromol 2021; 182:977-986. [PMID: 33887289 DOI: 10.1016/j.ijbiomac.2021.04.103] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 04/09/2021] [Accepted: 04/16/2021] [Indexed: 11/18/2022]
Abstract
Lignin is a complex phenolic biopolymer present in plant cell walls and a by-product of the cellulose pulping industry. Lignin has functional properties, such as antioxidant activity, that make it a potential natural active ingredient for health-care products. However, not all safety aspects of lignin fractions have been adequately investigated. Herein, we evaluated the antioxidant and genotoxic potential of two hardwood kraft lignins (F3 and F5). The chemical characterization of F3 and F5 demonstrated their thermal stability and the presence of different phenolic units, while the DPPH assay confirmed the antioxidant activity of these lignin fractions. Despite being antioxidants in the DPPH assay, F3 and F5 were capable of generating intracellular reactive oxygen species (ROS) and subsequently causing oxidative DNA damage (Comet assay) in HepG2 cells. The biological relevance of the DPPH assay might be uncertain in some cases; therefore, we suggest combining in chemico tests with biological system-based tests to determine efficacy and safety levels of lignins and define appropriate applications of lignins for consumer products. Moreover, kraft lignins obtained by acid precipitation may pose risks to human health; however, as genotoxicity is not the sole endpoint of toxicity required in hazard assessments, additional toxicological evaluations are needed.
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Affiliation(s)
- Emanoela Lundgren Thá
- Graduate Program in Genetics, Department of Genetics - Federal University of Paraná (UFPR), Curitiba, PR, Brazil
| | - Mailson Matos
- Graduate Program in Engineering and Materials Science (PIPE), Federal University of Paraná (UFPR), Curitiba, PR, Brazil
| | - Francisco Avelino
- Federal Institute of Education, Science and Technology of Ceará (IFCE), Iguatu, CE, Brazil
| | - Diego Lomonaco
- Department of Organic and Inorganic Chemistry - Federal University of Ceará (UFCE), Fortaleza, CE, Brazil
| | - Isisdoris Rodrigues-Souza
- Graduate Program in Genetics, Department of Genetics - Federal University of Paraná (UFPR), Curitiba, PR, Brazil
| | | | - Marta Margarete Cestari
- Graduate Program in Genetics, Department of Genetics - Federal University of Paraná (UFPR), Curitiba, PR, Brazil
| | - Washington Luiz Esteves Magalhães
- Graduate Program in Engineering and Materials Science (PIPE), Federal University of Paraná (UFPR), Curitiba, PR, Brazil; Embrapa Florestas, Colombo, PR, Brazil
| | - Daniela Morais Leme
- Graduate Program in Genetics, Department of Genetics - Federal University of Paraná (UFPR), Curitiba, PR, Brazil.
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16
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Fritsche E, Haarmann-Stemmann T, Kapr J, Galanjuk S, Hartmann J, Mertens PR, Kämpfer AAM, Schins RPF, Tigges J, Koch K. Stem Cells for Next Level Toxicity Testing in the 21st Century. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2006252. [PMID: 33354870 DOI: 10.1002/smll.202006252] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/13/2020] [Indexed: 06/12/2023]
Abstract
The call for a paradigm change in toxicology from the United States National Research Council in 2007 initiates awareness for the invention and use of human-relevant alternative methods for toxicological hazard assessment. Simple 2D in vitro systems may serve as first screening tools, however, recent developments infer the need for more complex, multicellular organotypic models, which are superior in mimicking the complexity of human organs. In this review article most critical organs for toxicity assessment, i.e., skin, brain, thyroid system, lung, heart, liver, kidney, and intestine are discussed with regards to their functions in health and disease. Embracing the manifold modes-of-action how xenobiotic compounds can interfere with physiological organ functions and cause toxicity, the need for translation of such multifaceted organ features into the dish seems obvious. Currently used in vitro methods for toxicological applications and ongoing developments not yet arrived in toxicity testing are discussed, especially highlighting the potential of models based on embryonic stem cells and induced pluripotent stem cells of human origin. Finally, the application of innovative technologies like organs-on-a-chip and genome editing point toward a toxicological paradigm change moves into action.
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Affiliation(s)
- Ellen Fritsche
- IUF - Leibniz Research Institute for Environmental Medicine, Düsseldorf, 40225, Germany
- Medical Faculty, Heinrich-Heine University Düsseldorf, Düsseldorf, 40225, Germany
| | | | - Julia Kapr
- IUF - Leibniz Research Institute for Environmental Medicine, Düsseldorf, 40225, Germany
| | - Saskia Galanjuk
- IUF - Leibniz Research Institute for Environmental Medicine, Düsseldorf, 40225, Germany
| | - Julia Hartmann
- IUF - Leibniz Research Institute for Environmental Medicine, Düsseldorf, 40225, Germany
| | - Peter R Mertens
- Department of Nephrology and Hypertension, Diabetes and Endocrinology, Otto-von-Guericke-University Magdeburg, Magdeburg, 39106, Germany
| | - Angela A M Kämpfer
- IUF - Leibniz Research Institute for Environmental Medicine, Düsseldorf, 40225, Germany
| | - Roel P F Schins
- IUF - Leibniz Research Institute for Environmental Medicine, Düsseldorf, 40225, Germany
| | - Julia Tigges
- IUF - Leibniz Research Institute for Environmental Medicine, Düsseldorf, 40225, Germany
| | - Katharina Koch
- IUF - Leibniz Research Institute for Environmental Medicine, Düsseldorf, 40225, Germany
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17
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Allemang A, Thacker R, DeMarco RA, Rodrigues MA, Pfuhler S. The 3D reconstructed skin micronucleus assay using imaging flow cytometry and deep learning: A proof-of-principle investigation. Mutat Res 2021; 865:503314. [PMID: 33865536 DOI: 10.1016/j.mrgentox.2021.503314] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 01/13/2021] [Accepted: 01/18/2021] [Indexed: 10/22/2022]
Abstract
The reconstructed skin micronucleus (RSMN) assay was developed in 2006, as an in vitro alternative for genotoxicity evaluation of dermally applied chemicals or products. In the years since, significant progress has been made in the optimization of the assay, including publication of a standard protocol and extensive validation. However, the diverse morphology of skin cells makes cell preparation and scoring of micronuclei (MN) tedious and subjective, thus requiring a high level of technical expertise for evaluation. This ultimately has a negative impact on throughput and the assay would benefit by the development of an automated method which could reduce scoring subjectivity while also improving the robustness of the assay by increasing the number of cells that can be scored. Imaging flow cytometry (IFC) with the ImageStream®X Mk II can capture high-resolution transmission and fluorescent imagery of cells in suspension. This proof-of-principle study describes protocol modifications that enable such automated measurement in 3D skin cells following exposure to mitomycin C and colchicine. IFC was then used for automated image capture and the Amnis® Artificial Intelligence (AAI) software permitted identification of binucleated (BN) cells with 91% precision. On average, three times as many BN cells from control samples were evaluated using IFC compared to the standard manual analysis. When IFC MNBN cells were visually scored from within the BN cell images, their frequency compared well with manual slide scoring, showing that IFC technology can be applied to the RSMN assay. This method enables faster time to result than microscope-based scoring and the initial studies presented here demonstrate its capability for the detection of statistically significant increases in MNBN frequencies. This work therefore demonstrates the feasibility of combining IFC and AAI to automate scoring for the RSMN assay and to improve its throughput and statistical robustness.
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Affiliation(s)
| | - Robert Thacker
- Amnis Flow Cytometry, Luminex Corporation, Austin, TX, USA
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18
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Chapman KE, Wilde EC, Chapman FM, Verma JR, Shah UK, Stannard LM, Seager AL, Tonkin JA, Brown MR, Doherty AT, Johnson GE, Doak SH, Jenkins GJS. Multiple-endpoint in vitro carcinogenicity test in human cell line TK6 distinguishes carcinogens from non-carcinogens and highlights mechanisms of action. Arch Toxicol 2021; 95:321-336. [PMID: 32910239 PMCID: PMC7811515 DOI: 10.1007/s00204-020-02902-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 09/02/2020] [Indexed: 12/12/2022]
Abstract
Current in vitro genotoxicity tests can produce misleading positive results, indicating an inability to effectively predict a compound's subsequent carcinogenic potential in vivo. Such oversensitivity can incur unnecessary in vivo tests to further investigate positive in vitro results, supporting the need to improve in vitro tests to better inform risk assessment. It is increasingly acknowledged that more informative in vitro tests using multiple endpoints may support the correct identification of carcinogenic potential. The present study, therefore, employed a holistic, multiple-endpoint approach using low doses of selected carcinogens and non-carcinogens (0.001-770 µM) to assess whether these chemicals caused perturbations in molecular and cellular endpoints relating to the Hallmarks of Cancer. Endpoints included micronucleus induction, alterations in gene expression, cell cycle dynamics, cell morphology and bioenergetics in the human lymphoblastoid cell line TK6. Carcinogens ochratoxin A and oestradiol produced greater Integrated Signature of Carcinogenicity scores for the combined endpoints than the "misleading" in vitro positive compounds, quercetin, 2,4-dichlorophenol and quinacrine dihydrochloride and toxic non-carcinogens, caffeine, cycloheximide and phenformin HCl. This study provides compelling evidence that carcinogens can successfully be distinguished from non-carcinogens using a holistic in vitro test system. Avoidance of misleading in vitro outcomes could lead to the reduction and replacement of animals in carcinogenicity testing.
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Affiliation(s)
- Katherine E Chapman
- In Vitro Toxicology Group, Institute of Life Science 1, Swansea University Medical School, Swansea University, Singleton Campus, Swansea, SA2 8PP, UK.
| | - Eleanor C Wilde
- In Vitro Toxicology Group, Institute of Life Science 1, Swansea University Medical School, Swansea University, Singleton Campus, Swansea, SA2 8PP, UK
| | - Fiona M Chapman
- In Vitro Toxicology Group, Institute of Life Science 1, Swansea University Medical School, Swansea University, Singleton Campus, Swansea, SA2 8PP, UK
| | - Jatin R Verma
- In Vitro Toxicology Group, Institute of Life Science 1, Swansea University Medical School, Swansea University, Singleton Campus, Swansea, SA2 8PP, UK
| | - Ume-Kulsoom Shah
- In Vitro Toxicology Group, Institute of Life Science 1, Swansea University Medical School, Swansea University, Singleton Campus, Swansea, SA2 8PP, UK
| | - Leanne M Stannard
- In Vitro Toxicology Group, Institute of Life Science 1, Swansea University Medical School, Swansea University, Singleton Campus, Swansea, SA2 8PP, UK
| | - Anna L Seager
- In Vitro Toxicology Group, Institute of Life Science 1, Swansea University Medical School, Swansea University, Singleton Campus, Swansea, SA2 8PP, UK
| | - James A Tonkin
- College of Engineering, Swansea University, Bay Campus, Swansea, SA1 8EN, UK
| | - M Rowan Brown
- College of Engineering, Swansea University, Bay Campus, Swansea, SA1 8EN, UK
| | - Ann T Doherty
- Discovery Safety, AstraZeneca, DSM, Darwin Building, Cambridge Science Park, Milton Road, Cambridge, CB4 0WG, UK
| | - George E Johnson
- In Vitro Toxicology Group, Institute of Life Science 1, Swansea University Medical School, Swansea University, Singleton Campus, Swansea, SA2 8PP, UK
| | - Shareen H Doak
- In Vitro Toxicology Group, Institute of Life Science 1, Swansea University Medical School, Swansea University, Singleton Campus, Swansea, SA2 8PP, UK
| | - Gareth J S Jenkins
- In Vitro Toxicology Group, Institute of Life Science 1, Swansea University Medical School, Swansea University, Singleton Campus, Swansea, SA2 8PP, UK
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19
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Li X, He X, Chen S, Guo X, Bryant MS, Guo L, Manjanatha MG, Zhou T, Witt KL, Mei N. Evaluation of pyrrolizidine alkaloid-induced genotoxicity using metabolically competent TK6 cell lines. Food Chem Toxicol 2020; 145:111662. [PMID: 32798647 PMCID: PMC9969979 DOI: 10.1016/j.fct.2020.111662] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/21/2020] [Accepted: 07/26/2020] [Indexed: 12/12/2022]
Abstract
Pyrrolizidine alkaloid (PA)-containing plants are among the most common poisonous plants affecting humans, livestock, and wildlife worldwide. A large number of PAs are known to induce genetic damage after metabolic activation. In the present study, using a battery of fourteen newly developed TK6 cell lines, each expressing a single human cytochrome P450 (CYP1A1, 1A2, 1B1, 2A6, 2B6, 2C8, 2C18, 2C9, 2C19, 2D6, 2E1, 3A4, 3A5, and 3A7), we identified specific CYPs responsible for bioactivating three PAs - lasiocarpine, riddelliine, and senkirkine. Among the fourteen cell lines, cells expressing CYP3A4 showed significant increases in PA-induced cytotoxicity, evidenced by decreased ATP production and cell viability, and increased caspase 3/7 activities. LC-MS/MS analysis revealed the formation of 1-hydroxymethyl-7-hydroxy-6,7-dihydropyrrolizine (DHP), the main reactive metabolite of PAs, in CYP3A4-expressing TK6 cells. DHP was also detected in CYP3A5- and 3A7-expressing cells after PA exposure, but to a much lesser extent. Subsequently, using a high-throughput micronucleus assay, we demonstrated that PAs induced concentration-dependent increases in micronuclei and G2/M phase cell cycle arrest in three CYP3A variant-expressing TK6 cell lines. Using Western blotting, we observed that PA-induced apoptosis, cell cycle changes, and DNA damage were primarily mediated by CYP3A4. Benchmark dose (BMD) modeling demonstrated that lasiocarpine, of the three PAs, was the most potent inducer of micronuclei, with a BMD100 of 0.036 μM. These results indicate that our TK6 cell system holds promise for genotoxicity screening of compounds requiring metabolic activation, identifying specific CYPs involved in bioactivation, and discriminating the genotoxic compounds that have different chemical structures.
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Affiliation(s)
- Xilin Li
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA
| | - Xiaobo He
- Office of Scientific Coordination, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA
| | - Si Chen
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA
| | - Xiaoqing Guo
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA
| | - Matthew S. Bryant
- Office of Scientific Coordination, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA
| | - Lei Guo
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA
| | - Mugimane G. Manjanatha
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA
| | - Tong Zhou
- Center for Veterinary Medicine, U.S. Food and Drug Administration, Rockville, MD 20855, USA
| | - Kristine L. Witt
- Divison of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Nan Mei
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, 72079, USA.
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20
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Johann S, Goßen M, Behnisch PA, Hollert H, Seiler TB. Combining Different In Vitro Bioassays to Evaluate Genotoxicity of Water-Accommodated Fractions from Petroleum Products. TOXICS 2020; 8:toxics8020045. [PMID: 32604793 PMCID: PMC7355774 DOI: 10.3390/toxics8020045] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 06/08/2020] [Accepted: 06/20/2020] [Indexed: 12/18/2022]
Abstract
Genotoxicity assessment is of high relevance for crude and refined petroleum products, since oil compounds are known to cause DNA damage with severe consequences for aquatic biota as demonstrated in long-term monitoring studies. This study aimed at the optimization and evaluation of small-scale higher-throughput assays (Ames fluctuation, micronucleus, Nrf2-CALUX®) covering different mechanistic endpoints as first screening tools for genotoxicity assessment of oils. Cells were exposed to native and chemically dispersed water-accommodated fractions (WAFs) of three oil types varying in their processing degree. Independent of an exogenous metabolic activation system, WAF compounds induced neither base exchange nor frame shift mutations in bacterial strains. However, significantly increased chromosomal aberrations in zebrafish liver (ZF-L) cells were observed. Oxidative stress was indicated for some treatments and was not correlated with observed DNA damage. Application of a chemical dispersant increased the genotoxic potential rather by the increased bioavailability of dissolved and particulate oil compounds. Nonetheless, the dispersant induced a clear oxidative stress response, indicating a relevance for general toxic stress. Results showed that the combination of different in vitro assays is important for a reliable genotoxicity assessment. Especially, the ZF-L capable of active metabolism and DNA repair seems to be a promising model for WAF testing.
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Affiliation(s)
- Sarah Johann
- Department of Evolutionary Ecology and Environmental Toxicology, Goethe University Frankfurt, Max-von-Laue-Str. 13, 60438 Frankfurt am Main, Germany; (M.G.); (H.H.)
- Department of Ecosystem Analysis, Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
- Correspondence: (S.J.); (T.-B.S.)
| | - Mira Goßen
- Department of Evolutionary Ecology and Environmental Toxicology, Goethe University Frankfurt, Max-von-Laue-Str. 13, 60438 Frankfurt am Main, Germany; (M.G.); (H.H.)
- Department of Ecosystem Analysis, Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Peter A. Behnisch
- BioDetection Systems b.v., Science Park 406, 1098 XH Amsterdam, The Netherlands;
| | - Henner Hollert
- Department of Evolutionary Ecology and Environmental Toxicology, Goethe University Frankfurt, Max-von-Laue-Str. 13, 60438 Frankfurt am Main, Germany; (M.G.); (H.H.)
- Department of Ecosystem Analysis, Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Thomas-Benjamin Seiler
- Department of Ecosystem Analysis, Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
- Correspondence: (S.J.); (T.-B.S.)
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21
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Al-Saleh I, Elkhatib R, Al-Rajoudi T, Al-Qudaihi G, Manogarannogaran P, Eltabache C, Alotaibi A, Mummer AB, Almugbel S. Cytotoxic and genotoxic effects of e-liquids and their potential associations with nicotine, menthol and phthalate esters. CHEMOSPHERE 2020; 249:126153. [PMID: 32058129 DOI: 10.1016/j.chemosphere.2020.126153] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 01/15/2020] [Accepted: 02/06/2020] [Indexed: 05/06/2023]
Abstract
In this study, we determined DNA damage and chromosome breakage (indicators of genotoxicity) and cell viability (an indicator of cytotoxicity) in human lymphoblastoid TK6 and Chinese hamster ovary (CHO) cells treated with 33 e-liquids using in vitro single cell gel (comet), micronucleus (MN), and trypan blue assays, respectively. We also measured the contents of nicotine, five phthalate esters, and DL-menthol in the e-liquids to examine their effects on DNA damage, chromosome breakage, and cell viability. Our chemical analyses showed that: (1) six e-liquids had nicotine ≥2-fold higher than the manufacture's label claim (2-3.5 mg); (2) both dimethyl- and dibutyl-phthalate levels were >0.1 μg/g, i.e., their threshold limits as additives in cosmetics; and (3) the DL-menthol contents ranged from 0.0003 to 85757.2 μg/g, with those of two e-liquids being >1 mg/g, the threshold limit for trigging sensory irritation. Though all the e-liquids induced DNA damage in TK6 cells, 20 resulted in cell viabilities ≤75%, indicating cytotoxicity, yet the inverse relationship between cell viability and DNA damage (r = -0.628, p = 0.003) might reflect their role as pro-apoptotic and DNA damage inducers. Fifteen e-liquids induced MN% in TK6 cells ≥3-fold that of untreated cells. Some of the increase in %MN might be false due to high cytotoxicity, yet six brands showed acceptable cell viabilities (59-71%), indicating chromosome damage. DNA damage and %MN increased when the TK6 cells were exposed to metabolic activation. The CHO cells were less sensitive to the genotoxic effects of the e-liquids than the TK6 cells. DL-menthol was found to be associated with decreased cell viability and increased DNA damage, even at low levels. We cannot dismiss the presence of other ingredients in e-liquids with cytotoxic/genotoxic properties since out of the 63 different flavors, 47 induced DNA damage (≥3-folds), and 26 reduced cell viability (≤75%) in TK6 cells.
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Affiliation(s)
| | | | | | | | | | | | - Aminah Alotaibi
- National Center for Biotechnology and Genomic Research, King Abdulaziz City for Science and Technology, Saudi Arabia
| | - Abdulrahman Bin Mummer
- Biostatistics, Epidemiology & Scientific Computing Department, King Faisal Specialist Hospital & Research Centre, Saudi Arabia
| | - Saad Almugbel
- College of Medicine, Al-Imam Muhammed Ibn Saud Islamic University, Riyadh, Saudi Arabia
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22
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Liu W, Xi J, Cao Y, You X, Chen R, Zhang X, Han L, Pan G, Luan Y. An Adaption of Human-Induced Hepatocytes to In Vitro Genetic Toxicity Tests. Mutagenesis 2020; 34:165-171. [PMID: 30590776 DOI: 10.1093/mutage/gey041] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Metabolic activation is essential in standard in vitro genotoxicity test systems. At present, there is a lack of suitable cell models that can express the major characteristics of liver function for predicting substance toxicity in humans. Human-induced hepatocytes (hiHeps), which have been generated from fibroblasts by lentiviral expression of liver transcription factors, can express hepatic gene programs and can be expanded in vitro and display functional characteristics of mature hepatocytes, including cytochrome P450 enzyme activity and biliary drug clearance. Our purpose was to investigate whether hiHeps could be used as a more suitable model for genotoxicity evaluation of chemicals. Therefore, a direct mutagen, methylmethanesulfonate (MMS), and five promutagens [2-nitrofluorene (2-NF), benzo[a]pyrene (B[a]P), aflatoxin B1, cyclophosphamide and N-nitrosodiethylamine] were tested by the cytokinesis-block micronucleus test and the comet assay. Results from genotoxicity tests showed that the micronucleus frequencies were significantly increased by all of the six clastogens tested. Moreover, MMS, 2-NF and B[a]P induced significant increases in the % Tail DNA in the comet assay. In conclusion, our findings from the preliminary study demonstrated that hiHeps could detect the genotoxicity of indirect carcinogens, suggesting their potential to be applied as an effective tool for in vitro genotoxicity assessments.
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Affiliation(s)
- Weiying Liu
- Hongqiao International Institute of Medicine, Shanghai Tong Ren Hospital and Faculty of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jing Xi
- Hongqiao International Institute of Medicine, Shanghai Tong Ren Hospital and Faculty of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yiyi Cao
- Hongqiao International Institute of Medicine, Shanghai Tong Ren Hospital and Faculty of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xinyue You
- Hongqiao International Institute of Medicine, Shanghai Tong Ren Hospital and Faculty of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ruixue Chen
- Hongqiao International Institute of Medicine, Shanghai Tong Ren Hospital and Faculty of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xinyu Zhang
- Hongqiao International Institute of Medicine, Shanghai Tong Ren Hospital and Faculty of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Li Han
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Guoyu Pan
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Yang Luan
- Hongqiao International Institute of Medicine, Shanghai Tong Ren Hospital and Faculty of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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23
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Gooderham NJ, Cohen SM, Eisenbrand G, Fukushima S, Guengerich FP, Hecht SS, Rietjens IMCM, Rosol TJ, Bastaki M, Linman MJ, Taylor SV. The safety evaluation of food flavoring substances: the role of genotoxicity studies. Crit Rev Toxicol 2020; 50:1-27. [PMID: 32162576 DOI: 10.1080/10408444.2020.1712589] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The Flavor and Extract Manufacturers Association (FEMA) Expert Panel relies on the weight of evidence from all available data in the safety evaluation of flavoring substances. This process includes data from genotoxicity studies designed to assess the potential of a chemical agent to react with DNA or otherwise cause changes to DNA, either in vitro or in vivo. The Panel has reviewed a large number of in vitro and in vivo genotoxicity studies during the course of its ongoing safety evaluations of flavorings. The adherence of genotoxicity studies to standardized protocols and guidelines, the biological relevance of the results from those studies, and the human relevance of these studies are all important considerations in assessing whether the results raise specific concerns for genotoxic potential. The Panel evaluates genotoxicity studies not only for evidence of genotoxicity hazard, but also for the probability of risk to the consumer in the context of exposure from their use as flavoring substances. The majority of flavoring substances have given no indication of genotoxic potential in studies evaluated by the FEMA Expert Panel. Examples illustrating the assessment of genotoxicity data for flavoring substances and the consideration of the factors noted above are provided. The weight of evidence approach adopted by the FEMA Expert Panel leads to a rational assessment of risk associated with consumer intake of flavoring substances under the conditions of use.
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Affiliation(s)
| | - Samuel M Cohen
- Havlik-Wall Professor of Oncology, Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Gerhard Eisenbrand
- Food Chemistry & Toxicology, University of Kaiserslautern (retired), Heidelberg, Germany
| | | | - F Peter Guengerich
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Stephen S Hecht
- Masonic Cancer Center and Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, USA
| | | | - Thomas J Rosol
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
| | - Maria Bastaki
- Flavor and Extract Manufacturers Association, Washington, DC, USA
| | - Matthew J Linman
- Flavor and Extract Manufacturers Association, Washington, DC, USA
| | - Sean V Taylor
- Flavor and Extract Manufacturers Association, Washington, DC, USA
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24
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Pfuhler S, van Benthem J, Curren R, Doak SH, Dusinska M, Hayashi M, Heflich RH, Kidd D, Kirkland D, Luan Y, Ouedraogo G, Reisinger K, Sofuni T, van Acker F, Yang Y, Corvi R. Use of in vitro 3D tissue models in genotoxicity testing: Strategic fit, validation status and way forward. Report of the working group from the 7 th International Workshop on Genotoxicity Testing (IWGT). Mutat Res 2020; 850-851:503135. [PMID: 32247552 DOI: 10.1016/j.mrgentox.2020.503135] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 01/09/2020] [Indexed: 12/25/2022]
Abstract
Use of three-dimensional (3D) tissue equivalents in toxicology has been increasing over the last decade as novel preclinical test systems and as alternatives to animal testing. In the area of genetic toxicology, progress has been made with establishing robust protocols for skin, airway (lung) and liver tissue equivalents. In light of these advancements, a "Use of 3D Tissues in Genotoxicity Testing" working group (WG) met at the 7th IWGT meeting in Tokyo in November 2017 to discuss progress with these models and how they may fit into a genotoxicity testing strategy. The workshop demonstrated that skin models have reached an advanced state of validation following over 10 years of development, while liver and airway model-based genotoxicity assays show promise but are at an early stage of development. Further effort in liver and airway model-based assays is needed to address the lack of coverage of the three main endpoints of genotoxicity (mutagenicity, clastogenicity and aneugenicity), and information on metabolic competence. The IWGT WG believes that the 3D skin comet and micronucleus assays are now sufficiently validated to undergo an independent peer review of the validation study, followed by development of individual OECD Test Guidelines.
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Affiliation(s)
- Stefan Pfuhler
- Procter and Gamble, Mason Business Centre, Mason, OH, USA.
| | - Jan van Benthem
- National Institute for Public Health and the Environment, Centre for Health Protection, Bilthoven, the Netherlands
| | - Rodger Curren
- Institute for In Vitro Sciences, Inc., Gaithersburg, MD, USA
| | - Shareen H Doak
- Swansea University Medical School, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Maria Dusinska
- Health Effects Laboratory, Department of Environmental Chemistry, NILU-Norwegian Institute for Air Research, Kjeller, Norway
| | | | - Robert H Heflich
- U.S. Food and Drug Administration/National Center for Toxicological Research, Jefferson, AR, USA
| | - Darren Kidd
- Covance Laboratories Ltd, Otley Road, Harrogate, HG3 1PY, UK
| | | | - Yang Luan
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, PR China
| | | | | | - Toshio Sofuni
- Formerly National Institute of Health Sciences, Tokyo, Japan
| | | | - Ying Yang
- Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, PR China
| | - Raffaella Corvi
- European Commission, Joint Research Centre (JRC), Ispra, Italy
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25
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Tsafantakis N, Katsanou ES, Kyriakopoulou K, Psarou EC, Raptaki I, Skaltsounis AL, Audebert M, Machera KA, Fokialakis N. Comparative UHPLC-HRMS Profiling, Toxicological Assessment, and Protection Against H 2O 2-Induced Genotoxicity of Different Parts of Opuntia ficus indica. J Med Food 2019; 22:1280-1293. [PMID: 31584314 DOI: 10.1089/jmf.2019.0032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Opuntia ficus indica has been an important dietary source and a traditionally used medicinal plant. Given the promising health-promoting properties of this plant, a comparative toxicological assessment and antioxidant bioevaluation of extracts from different parts of the plant were carried out in relation to their chemical profile. Toxicity was examined at multiple endpoints using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), Comet and the γH2AX In-Cell Western Assay, while hyphenated ultra-high-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) analysis was carried out to identify main constituents. None of the extracts showed any cytotoxic and genotoxic effect on cell lines used, apart from the flower extract in HepG2 cells at the highest concentration tested (2.5 mg/mL). Both fruit flesh and seed extracts demonstrated a prominent protective effect against H2O2-induced genotoxicity in almost all concentrations tested, while extracts originated from flowers and cladodes were effective only at the low non-cytotoxic (0.312 and 0.625 mg/mL) and high (1.25 and 2.5 mg/mL) concentrations, respectively. In total, 2 phenolic acids, 12 flavonoids, along with 3 feruloyl derivatives and the plant pigment indicaxanthin, were tentatively identified by UHPLC-HRMS analysis. Phenolic acids (compounds 1 and 2) were mainly distributed in cladodes (64.6%), while flavonoids (3-14) in the flowers (81.8%). Overall, the highest amount of total flavonoids (22.76 ± 0.015 mg of quercetin equivalent [QE]/g) and total phenolics (62.80 ± 0.009 mg gallic acid equivalents [GAE]/g) was found in the flower extract. Flavonoid glycosides have not been detected in the seeds and the flesh, while the fruit seed extract contained mainly feruloyl derivatives. Our data provide convincing evidences for the lack of cytotoxic and genotoxic effects of O. ficus indica aqueous extracts and, in parallel, support the potential for further exploitation of this plant in the food supplement or functional food sector.
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Affiliation(s)
- Nikolaos Tsafantakis
- Department of Pharmacognosy and Natural Products Chemistry, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece
| | - Efrosini S Katsanou
- Laboratory of Pesticides Toxicology, Department of Pesticides Control & Phytopharmacy, Benaki Phytopathological Institute, Athens, Greece
| | - Katerina Kyriakopoulou
- Laboratory of Pesticides Toxicology, Department of Pesticides Control & Phytopharmacy, Benaki Phytopathological Institute, Athens, Greece
| | - Eirini-Christina Psarou
- Laboratory of Pesticides Toxicology, Department of Pesticides Control & Phytopharmacy, Benaki Phytopathological Institute, Athens, Greece
| | - Iliana Raptaki
- Laboratory of Pesticides Toxicology, Department of Pesticides Control & Phytopharmacy, Benaki Phytopathological Institute, Athens, Greece
| | - Alexios L Skaltsounis
- Department of Pharmacognosy and Natural Products Chemistry, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece
| | - Marc Audebert
- UMR1331 Toxalim, Research Centre in Food Toxicology, INRA, Toulouse, France
| | - Kyriaki A Machera
- Laboratory of Pesticides Toxicology, Department of Pesticides Control & Phytopharmacy, Benaki Phytopathological Institute, Athens, Greece
| | - Nikolas Fokialakis
- Department of Pharmacognosy and Natural Products Chemistry, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece
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26
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Liang Z, Yin P, Zhao L. Effects of combined toxicity of methamphetamine and ketamine on apoptosis, oxidative stress and genotoxicity in HepG2 cells. Food Chem Toxicol 2019; 132:110653. [DOI: 10.1016/j.fct.2019.110653] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 06/27/2019] [Accepted: 06/28/2019] [Indexed: 01/14/2023]
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27
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Li J, Settivari RS, LeBaron MJ. Genetic instability of in vitro cell lines: Implications for genetic toxicity testing. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2019; 60:559-562. [PMID: 30848522 DOI: 10.1002/em.22280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 02/28/2019] [Accepted: 03/04/2019] [Indexed: 06/09/2023]
Abstract
Cell line-based in vitro testing has been widely used as an important component of the genotoxicity testing battery; however, the use of cell lines is constrained by several limitations, including the genetic drift and variability. A study recently reported in the literature comprehensively examined genomic changes in a large number of cell lines and reported extensive genetic variations within the same cell lines across passage numbers and laboratories, even for single-cell derived subclones. The primary objective of this communication is to raise awareness and stimulate discussion within the genotoxicity testing community of the extent of genetic variability of cell lines in general and how these variables could potentially influence the results and reproducibility of genotoxicity testing. Meanwhile, some recommendations for good cell culture practices are highlighted to mitigate, at least to some extent, the concern about genetic variation. Environ. Mol. Mutagen. 60:559-562, 2019. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Jinpeng Li
- Toxicology & Environmental Research and Consulting, The Dow Chemical Company, Midland, Michigan
| | - Raja S Settivari
- Toxicology & Environmental Research and Consulting, The Dow Chemical Company, Midland, Michigan
| | - Matthew J LeBaron
- Toxicology & Environmental Research and Consulting, The Dow Chemical Company, Midland, Michigan
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28
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Mišík M, Nersesyan A, Bolognesi C, Kundi M, Ferk F, Knasmueller S. Cytome micronucleus assays with a metabolically competent human derived liver cell line (Huh6): A promising approach for routine testing of chemicals? ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2019; 60:134-144. [PMID: 30408237 PMCID: PMC6492180 DOI: 10.1002/em.22254] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 09/03/2018] [Accepted: 09/28/2018] [Indexed: 05/05/2023]
Abstract
One of the main problems of in vitro genotoxicity tests is the inadequate representation of drug metabolizing enzymes in most indicator cell lines which are currently used. We identified recently a human derived liver cell line (Huh6) which detected induction of DNA damage by representatives of different groups of promutagens without enzyme mix and showed that these cells are more suitable in terms of reproducibility and sensitivity as other currently used liver derived lines. We developed a protocol for micronucleus (MN) cytome assays with these cells and validated the procedure in experiments with representatives of different groups of directly and indirectly acting genotoxic carcinogens (MMS, cisplatin, PhIP, IQ, NDMA, B(a)P, AFB1, etoposide, and H2 O2 ). The optimal cytochalasin B concentration in combination with 48 hr treatment was found to be 1.5 μg/mL and leads to a cytokinesis block proliferation index in the range between 1.7 and 2.0. The morphological characteristics of different nuclear anomalies which reflect DNA damage (MN, nuclear bridges, and buds) and their baseline frequencies in untreated cells were characterized, and the rates which are required to cause significant effects were calculated. All compounds caused dose dependent induction of MN when the cells were treated for 24 hr, longer and shorter exposure times were less effective. Experiments with different serum levels (fetal bovine serum [FBS]) showed that 10% FBS in the medium (instead of 4%) causes a substantial increase of the sensitivity of the cells. Our results indicate that the new protocol is a promising approach for routine testing of chemicals. Environ. Mol. Mutagen. 60: 134-144, 2019. © 2018 The Authors. Environmental and Molecular Mutagenesis published by Wiley Periodicals, Inc. on behalf of Environmental Mutagen Society.
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Affiliation(s)
- Miroslav Mišík
- Institute of Cancer Research, Department of Internal Medicine 1Medical University of ViennaViennaAustria
| | - Armen Nersesyan
- Institute of Cancer Research, Department of Internal Medicine 1Medical University of ViennaViennaAustria
| | - Claudia Bolognesi
- Environmental Carcinogenesis UnitOspedale Policlinico San MartinoGenoaItaly
| | - Michael Kundi
- Center for Public Health, Department of Environmental HealthMedical University of ViennaViennaAustria
| | - Franziska Ferk
- Institute of Cancer Research, Department of Internal Medicine 1Medical University of ViennaViennaAustria
| | - Siegfried Knasmueller
- Institute of Cancer Research, Department of Internal Medicine 1Medical University of ViennaViennaAustria
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29
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Yu JR, Navarro J, Coburn JC, Mahadik B, Molnar J, Holmes JH, Nam AJ, Fisher JP. Current and Future Perspectives on Skin Tissue Engineering: Key Features of Biomedical Research, Translational Assessment, and Clinical Application. Adv Healthc Mater 2019; 8:e1801471. [PMID: 30707508 PMCID: PMC10290827 DOI: 10.1002/adhm.201801471] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 01/04/2019] [Indexed: 12/20/2022]
Abstract
The skin is responsible for several important physiological functions and has enormous clinical significance in wound healing. Tissue engineered substitutes may be used in patients suffering from skin injuries to support regeneration of the epidermis, dermis, or both. Skin substitutes are also gaining traction in the cosmetics and pharmaceutical industries as alternatives to animal models for product testing. Recent biomedical advances, ranging from cellular-level therapies such as mesenchymal stem cell or growth factor delivery, to large-scale biofabrication techniques including 3D printing, have enabled the implementation of unique strategies and novel biomaterials to recapitulate the biological, architectural, and functional complexity of native skin. This progress report highlights some of the latest approaches to skin regeneration and biofabrication using tissue engineering techniques. Current challenges in fabricating multilayered skin are addressed, and perspectives on efforts and strategies to meet those limitations are provided. Commercially available skin substitute technologies are also examined, and strategies to recapitulate native physiology, the role of regulatory agencies in supporting translation, as well as current clinical needs, are reviewed. By considering each of these perspectives while moving from bench to bedside, tissue engineering may be leveraged to create improved skin substitutes for both in vitro testing and clinical applications.
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Affiliation(s)
- Justine R Yu
- Fischell Department of Bioengineering, University of Maryland, College Park, College Park, MD, 20742, USA
- NIH/NBIB Center for Engineering Complex Tissues, University of Maryland, College Park, College Park, MD, 20742, USA
- University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Javier Navarro
- Fischell Department of Bioengineering, University of Maryland, College Park, College Park, MD, 20742, USA
- NIH/NBIB Center for Engineering Complex Tissues, University of Maryland, College Park, College Park, MD, 20742, USA
| | - James C Coburn
- Fischell Department of Bioengineering, University of Maryland, College Park, College Park, MD, 20742, USA
- Division of Biomedical Physics, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, 20903, USA
| | - Bhushan Mahadik
- Fischell Department of Bioengineering, University of Maryland, College Park, College Park, MD, 20742, USA
- NIH/NBIB Center for Engineering Complex Tissues, University of Maryland, College Park, College Park, MD, 20742, USA
| | - Joseph Molnar
- Wake Forest Baptist Medical Center, Winston-Salem, NC, 27157, USA
| | - James H Holmes
- Wake Forest Baptist Medical Center, Winston-Salem, NC, 27157, USA
| | - Arthur J Nam
- Division of Plastic, Reconstructive and Maxillofacial Surgery, R. Adams Cowley Shock Trauma Center, University of Maryland, Baltimore, Baltimore, MD, 21201, USA
| | - John P Fisher
- Fischell Department of Bioengineering, University of Maryland, College Park, College Park, MD, 20742, USA
- NIH/NBIB Center for Engineering Complex Tissues, University of Maryland, College Park, College Park, MD, 20742, USA
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30
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Abstract
Anthropogenic activities, indiscriminate and rapid industrialization as well as pursuance of a better life has led to an increase in the concentration of chemicals, like pesticides, automobile exhausts, and new chemical entities, in the environment, which have an adverse effect on all living organisms including humans. Sensitive and robust test systems are thus required for accurate hazard identification and risk assessment. The Comet assay has been used widely as a simple, rapid, and sensitive tool for assessment of DNA damage in single cell from both in vitro and in vivo sources as well as in humans. The advantages of the in vivo Comet assay are its ability to detect DNA damage in any tissues, despite having non-proliferating cells, and its sensitivity to detect genotoxicity. The recommendations from the international workshops held for the Comet assay have resulted in establishment of guidelines, and the OECD has adopted a guideline for the in vivo Comet assay as a test for assessing DNA damage in animals. The in vitro Comet assay conducted in cultured cells can be used for screening large number of compounds and at very low concentrations. The in vitro assay has also been automated to provide a high throughput screening method for new chemical entities, as well as in environmental samples. This chapter details the in vitro Comet assay using the 96-well plate and in vivo Comet assay in multiple organs of the mouse.
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Affiliation(s)
| | - Ashutosh Kumar
- Biological and Life Sciences, School of Arts and Sciences, Ahmedabad University, Ahmedabad, Gujarat, India
| | - Alok Dhawan
- Nanomaterial Toxicology Group, CSIR-Indian Institute of Toxicology Research, Lucknow, Uttar Pradesh, India.
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31
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Pereira I, Fraga S, Silva S, Teixeira JP, Gama M. In vitro genotoxicity assessment of an oxidized dextrin-based hydrogel for biomedical applications. J Appl Toxicol 2018; 39:639-649. [PMID: 30485472 DOI: 10.1002/jat.3754] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 10/01/2018] [Accepted: 10/15/2018] [Indexed: 01/13/2023]
Abstract
Hydrogels are three-dimensional, crosslinked networks of hydrophilic polymers swollen with a large amount of water or biological fluids, without dissolving. Dextrin, a low-molecular-weight carbohydrate composed by glucose residues, has been used to develop an injectable hydrogel for biomedical applications. Dextrin was first oxidized to introduce aldehyde groups, which then reticulate with adipic acid dihydrazide, forming the dextrin-based hydrogel (HG). The HG and its components were tested for cyto- and genotoxicity according to the International Standard ISO 10993-3 on the biological evaluation of medical devices. To assess genotoxicity, a battery of in vitro genotoxicity tests employing both eukaryotic and prokaryotic models was performed: comet assay, cytokinesis-block micronucleus assay and Ames test. Our data revealed that the HG (IC50 = 2.8 mg/mL) and oxidized dextrin by itself (IC50 = 1.2 mg/mL) caused a concentration-dependent decrease in cellular viability of human lymphoblastoid TK6 cells after 24 hours of exposure to the test agents. However, these concentrations are unlikely to be reached in vivo. In addition, no significant increase in the DNA and chromosomal damage of TK6 cells exposed to non-cytotoxic concentrations of the HG and its isolated components was detected. Furthermore, neither the HG nor its metabolites exerted a mutagenic effect in different of Salmonella typhimurium strains and in an Escherichia coli mix. Our data demonstrated the genocompatibility of the HG (up to 3.5 mg/mL) for biomedical applications. To our best acknowledge, this is the first report with a detailed genotoxicity assessment of an aldehyde-modified polysaccharide/adipic acid dihydrazide hydrogel.
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Affiliation(s)
- Isabel Pereira
- CEB-Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Sónia Fraga
- Departamento de Saúde Ambiental, Instituto Nacional de Saúde Dr. Ricardo Jorge, 4000-055, Porto, Portugal.,EPIUnit-Instituto de Saúde Pública, Universidade do Porto, 4050-600, Porto, Portugal
| | - Susana Silva
- Departamento de Saúde Ambiental, Instituto Nacional de Saúde Dr. Ricardo Jorge, 4000-055, Porto, Portugal.,EPIUnit-Instituto de Saúde Pública, Universidade do Porto, 4050-600, Porto, Portugal
| | - João Paulo Teixeira
- Departamento de Saúde Ambiental, Instituto Nacional de Saúde Dr. Ricardo Jorge, 4000-055, Porto, Portugal.,EPIUnit-Instituto de Saúde Pública, Universidade do Porto, 4050-600, Porto, Portugal
| | - Miguel Gama
- CEB-Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal
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32
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Guo J, Shi R, Cao Y, Luan Y, Zhou Y, Gao Y, Tian Y. Genotoxic effects of imidacloprid in human lymphoblastoid TK6 cells. Drug Chem Toxicol 2018; 43:208-212. [DOI: 10.1080/01480545.2018.1497048] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Jingyi Guo
- Department of Environmental Health, School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Rong Shi
- Department of Environmental Health, School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yiyi Cao
- Department of Environmental Health, School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yang Luan
- Department of Environmental Health, School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yijun Zhou
- Department of Environmental Health, School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yu Gao
- Department of Environmental Health, School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ying Tian
- Department of Environmental Health, School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Waldherr M, Mišík M, Ferk F, Tomc J, Žegura B, Filipič M, Mikulits W, Mai S, Haas O, Huber WW, Haslinger E, Knasmüller S. Use of HuH6 and other human-derived hepatoma lines for the detection of genotoxins: a new hope for laboratory animals? Arch Toxicol 2017; 92:921-934. [PMID: 29218508 PMCID: PMC5818615 DOI: 10.1007/s00204-017-2109-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 10/26/2017] [Indexed: 12/20/2022]
Abstract
Cell lines which are currently used in genotoxicity tests lack enzymes which activate/detoxify mutagens. Therefore, rodent-derived liver preparations are used which reflect their metabolism in humans only partly; as a consequence misleading results are often obtained. Previous findings suggest that certain liver cell lines express phase I/II enzymes and detect promutagens without activation; however, their use is hampered by different shortcomings. The aim of this study was the identification of a suitable cell line. The sensitivity of twelve hepatic cell lines was investigated in single cell gel electrophoresis assays. Furthermore, characteristics of these lines were studied which are relevant for their use in genotoxicity assays (mitotic activity, p53 status, chromosome number, and stability). Three lines (HuH6, HCC1.2, and HepG2) detected representatives of five classes of promutagens, namely, IQ and PhIP (HAAs), B(a)P (PAH), NDMA (nitrosamine), and AFB1 (aflatoxin), and were sensitive towards reactive oxygen species (ROS). In contrast, the commercially available line HepaRG, postulated to be a surrogate for hepatocytes and an ideal tool for mutagenicity tests, did not detect IQ and was relatively insensitive towards ROS. All other lines failed to detect two or more compounds. HCC1.2 cells have a high and unstable chromosome number and mutated p53, these features distract from its use in routine screening. HepG2 was frequently employed in earlier studies, but pronounced inter-laboratory variations were observed. HuH6 was never used in genotoxicity experiments and is highly promising, it has a stable karyotype and we demonstrated that the results of genotoxicity experiments are reproducible.
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Affiliation(s)
- Monika Waldherr
- Department of Internal Medicine I, Institute of Cancer Research, Medical University Vienna, Borschkegasse 8a, 1090, Vienna, Austria
| | - Miroslav Mišík
- Department of Internal Medicine I, Institute of Cancer Research, Medical University Vienna, Borschkegasse 8a, 1090, Vienna, Austria
| | - Franziska Ferk
- Department of Internal Medicine I, Institute of Cancer Research, Medical University Vienna, Borschkegasse 8a, 1090, Vienna, Austria
| | - Jana Tomc
- Department for Genetic Toxicology and Cancer Biology, National Institute of Biology, Večna pot 111, Ljubljana, Slovenia
- Jozef Stefan International Postgraduate School, Jamova cesta 39, 1000, Ljubljana, Slovenia
| | - Bojana Žegura
- Department for Genetic Toxicology and Cancer Biology, National Institute of Biology, Večna pot 111, Ljubljana, Slovenia
| | - Metka Filipič
- Department for Genetic Toxicology and Cancer Biology, National Institute of Biology, Večna pot 111, Ljubljana, Slovenia
| | - Wolfgang Mikulits
- Department of Internal Medicine I, Institute of Cancer Research, Medical University Vienna, Borschkegasse 8a, 1090, Vienna, Austria
| | - Sören Mai
- Labdia Labordiagnostik GmbH, Zimmermannplatz 8, 1090, Vienna, Austria
| | - Oskar Haas
- Labdia Labordiagnostik GmbH, Zimmermannplatz 8, 1090, Vienna, Austria
| | - Wolfgang W Huber
- Department of Internal Medicine I, Institute of Cancer Research, Medical University Vienna, Borschkegasse 8a, 1090, Vienna, Austria
| | - Elisabeth Haslinger
- Department of Internal Medicine I, Institute of Cancer Research, Medical University Vienna, Borschkegasse 8a, 1090, Vienna, Austria
| | - Siegfried Knasmüller
- Department of Internal Medicine I, Institute of Cancer Research, Medical University Vienna, Borschkegasse 8a, 1090, Vienna, Austria.
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Lovell DP, Fellows M, Marchetti F, Christiansen J, Elhajouji A, Hashimoto K, Kasamoto S, Li Y, Masayasu O, Moore MM, Schuler M, Smith R, Stankowski LF, Tanaka J, Tanir JY, Thybaud V, Van Goethem F, Whitwell J. Analysis of negative historical control group data from the in vitro micronucleus assay using TK6 cells. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2017; 825:40-50. [PMID: 29307374 DOI: 10.1016/j.mrgentox.2017.10.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 10/23/2017] [Accepted: 10/24/2017] [Indexed: 10/18/2022]
Abstract
The recent revisions of the Organisation for Economic Co-operation and Development (OECD) genetic toxicology test guidelines emphasize the importance of historical negative controls both for data quality and interpretation. The goal of a HESI Genetic Toxicology Technical Committee (GTTC) workgroup was to collect data from participating laboratories and to conduct a statistical analysis to understand and publish the range of values that are normally seen in experienced laboratories using TK6 cells to conduct the in vitro micronucleus assay. Data from negative control samples from in vitro micronucleus assays using TK6 cells from 13 laboratories were collected using a standard collection form. Although in some cases statistically significant differences can be seen within laboratories for different test conditions, they were very small. The mean incidence of micronucleated cells/1000 cells ranged from 3.2/1000 to 13.8/1000. These almost four-fold differences in micronucleus levels cannot be explained by differences in scoring method, presence or absence of exogenous metabolic activation (S9), length of treatment, presence or absence of cytochalasin B or different solvents used as vehicles. The range of means from the four laboratories using flow cytometry methods (3.7-fold: 3.5-12.9 micronucleated cells/1000 cells) was similar to that from the nine laboratories using other scoring methods (4.3-fold: 3.2-13.8 micronucleated cells/1000 cells). No laboratory could be identified as an outlier or as showing unacceptably high variability. Quality Control (QC) methods applied to analyse the intra-laboratory variability showed that there was evidence of inter-experimental variability greater than would be expected by chance (i.e. over-dispersion). However, in general, this was low. This study demonstrates the value of QC methods in helping to analyse the reproducibility of results, building up a 'normal' range of values, and as an aid to identify variability within a laboratory in order to implement processes to maintain and improve uniformity.
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Affiliation(s)
- David P Lovell
- St George's Medical School, University of London, London, SW17 0RE, UK.
| | - Mick Fellows
- Astra Zeneca, Drug Safety and Metabolism, Cambridge, CB4 0WG, UK
| | - Francesco Marchetti
- Environmental Health Science Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Joan Christiansen
- Department of Exploratory Toxicology, H. Lundbeck A/S, Ottiliavej 9, DK-2500, Valby, Denmark
| | - Azeddine Elhajouji
- Novartis Institutes for Biomedical Research, Preclinical Safety, Basel, Switzerland
| | - Kiyohiro Hashimoto
- Takeda Pharmaceutical Company Limited Drug Safety Research Laboratories, Pharmaceutical Research Division 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Sawako Kasamoto
- Genotoxicology Laboratory, Public Interest Incorporation Foundation Biosafety Research Center (BSRC), 582-2, Shioshinden, Iwata, Shizuoka, 437-1213, Japan
| | - Yan Li
- U.S. Food and Drug Administration, National Center for Toxicological Research, USA
| | - Ozaki Masayasu
- Canon, Inc., Quality Management Headquarters, Chemical Safety Management Division, Chemical Safety Evaluation Department 1, Japan
| | | | | | - Robert Smith
- Covance Laboratories Ltd, Harrogate, HG3 1PY, UK
| | | | - Jin Tanaka
- Genotoxicology Laboratory, Public Interest Incorporation Foundation Biosafety Research Center (BSRC), 582-2, Shioshinden, Iwata, Shizuoka, 437-1213, Japan
| | - Jennifer Y Tanir
- ILSI Health and Environmental Sciences Institute (HESI), 1156 15th Street NW, 2nd Floor, Washington, DC 20005, USA
| | - Veronique Thybaud
- Sanofi, Drug Disposition, Safety and Animal Research, Vitry-sur-Seine, France
| | - Freddy Van Goethem
- Discovery Toxicology & Translational Safety Sciences, Janssen R&D, Turnhoutseweg 30, 2340 Beerse, Belgium
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35
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Maertens RM, Long AS, White PA. Performance of the in vitro transgene mutation assay in MutaMouse FE1 cells: Evaluation of nine misleading ("False") positive chemicals. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2017; 58:582-591. [PMID: 28843037 DOI: 10.1002/em.22125] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 07/20/2017] [Accepted: 07/20/2017] [Indexed: 06/07/2023]
Abstract
The screening of chemicals for the protection of human health and the environment requires the assessment of genetic toxicity. However, existing, internationally-accepted in vitro mammalian genotoxicity tests have been criticized for their low specificity (i.e. high frequency of "false" or "misleading" positive results for compounds that are negative in vivo). An in vitro transgene mutation assay has been established that uses a metabolically competent cell line derived from MutaMouse lung (i.e. FE1 cells). Mutation scoring employs the well-characterized lacZ positive selection system, and the assay is proposed as an alternative in vitro assessment tool. In this study, the performance of the FE1 cell assay was evaluated by examining responses to nine non-DNA-reactive chemicals that previously elicited misleading positive results in other mammalian cell genotoxicity assays. FE1 cells were exposed to concentrations up to approximately 10 mM and/or concentrations that yielded approximately 80-90% cytotoxicity (as measured by relative increase in cell count). The assay demonstrated excellent specificity; exposures to the chemicals examined did not yield any positive responses even when tested in the presence of an exogenous metabolic activation system (i.e. S9) or with an extended sampling time. These results indicate that the FE1 cell mutagenicity assay is an effective and practical alternative to traditional mammalian cell gene mutation assays. The development and validation of effective in vitro tools such as the MutaMouse FE1 cell assay will contribute to international efforts to reduce, refine, and replace experimental animals for toxicity assessment. Environ. Mol. Mutagen. 58:582-591, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Rebecca M Maertens
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada
| | - Alexandra S Long
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada
| | - Paul A White
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada
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36
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Li X, Yin P, Zhao L. Effects of individual and combined toxicity of bisphenol A, dibutyl phthalate and cadmium on oxidative stress and genotoxicity in HepG 2 cells. Food Chem Toxicol 2017; 105:73-81. [DOI: 10.1016/j.fct.2017.03.054] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 03/24/2017] [Accepted: 03/27/2017] [Indexed: 11/12/2022]
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37
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Brusick D, Aardema M, Kier L, Kirkland D, Williams G. Genotoxicity Expert Panel review: weight of evidence evaluation of the genotoxicity of glyphosate, glyphosate-based formulations, and aminomethylphosphonic acid. Crit Rev Toxicol 2016; 46:56-74. [DOI: 10.1080/10408444.2016.1214680] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
| | | | - Larry Kier
- Private Consultant, Buena Vista, CO, USA
| | | | - Gary Williams
- Pathology, New York Medical College, Valhalla, NY, USA
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38
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Corvi R, Madia F. In vitro genotoxicity testing-Can the performance be enhanced? Food Chem Toxicol 2016; 106:600-608. [PMID: 27554597 DOI: 10.1016/j.fct.2016.08.024] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 08/18/2016] [Accepted: 08/19/2016] [Indexed: 12/16/2022]
Abstract
The assessment of genotoxicity represents an essential component of the safety assessment of all types of substances. Several in vitro tests are available at different stages of development and acceptance, yet they are not considered at present sufficient to fully replace animal tests needed to evaluate the safety of substances. For an overall improvement of the traditional genotoxicity testing paradigm, several recent activities have taken place. These include the improvement of existing tests, the development of novel tests, as well as, the establishment and exploration of approaches to optimise in vitro testing accuracy. Furthermore, useful tools, such as databases or reference chemical lists have been developed to support advances in this field.
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Affiliation(s)
- Raffaella Corvi
- European Commission, Joint Research Centre (JRC), Directorate Health, Consumers and Reference Materials, Chemicals Safety and Alternative Methods Unit, EURL ECVAM, Via E. Fermi 2749, I-21027, Ispra, Varese, Italy.
| | - Federica Madia
- European Commission, Joint Research Centre (JRC), Directorate Health, Consumers and Reference Materials, Chemicals Safety and Alternative Methods Unit, EURL ECVAM, Via E. Fermi 2749, I-21027, Ispra, Varese, Italy.
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39
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Roursgaard M, Knudsen KB, Northeved H, Persson M, Christensen T, Kumar PEK, Permin A, Andresen TL, Gjetting T, Lykkesfeldt J, Vesterdal LK, Loft S, Møller P. In vitro toxicity of cationic micelles and liposomes in cultured human hepatocyte (HepG2) and lung epithelial (A549) cell lines. Toxicol In Vitro 2016; 36:164-171. [PMID: 27497994 DOI: 10.1016/j.tiv.2016.08.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 07/14/2016] [Accepted: 08/02/2016] [Indexed: 12/22/2022]
Abstract
The aim of this study was to compare the effects of cationic micelle and liposome drug delivery systems on liver and lung cells in a toxicological in vitro screening model, with observations on cytotoxicity and genotoxicity. A screening battery was established for assessment of a broad range of parameters related to adverse effects. Clear concentration response effects were observed related to impairment of mitochondrial function, membrane integrity and oxidative stress markers, but no effect was observed on genotoxicity. The adverse effects were highest for the liposomes. The High Content Screening seems optimal for initial screening of adverse effects, and combined with standard cytotoxicity measurements initial screening can be performed for predictive toxicological screening.
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Affiliation(s)
- Martin Roursgaard
- Faculty of Health and Medical Science, Department of Public Health, Section of Environmental Health, University of Copenhagen, Denmark.
| | - Kristina Bram Knudsen
- Faculty of Health and Medical Science, Department of Public Health, Section of Environmental Health, University of Copenhagen, Denmark; National Research Center for the Working Environment, Copenhagen, Denmark; H. Lundbeck A/S, Valby, Denmark
| | | | | | | | - Pramod E K Kumar
- Center for Nanomedicine and Theranostics, Technical University of Denmark, DTU Nanotech, Lyngby, Denmark
| | - Anders Permin
- DTU Food, Technical University of Denmark, Søborg, Denmark
| | - Thomas L Andresen
- Center for Nanomedicine and Theranostics, Technical University of Denmark, DTU Nanotech, Lyngby, Denmark
| | - Torben Gjetting
- Center for Nanomedicine and Theranostics, Technical University of Denmark, DTU Nanotech, Lyngby, Denmark
| | - Jens Lykkesfeldt
- Faculty of Health and Medical Science, Department of Public Health, Section of Environmental Health, University of Copenhagen, Denmark
| | - Lise K Vesterdal
- Faculty of Health and Medical Science, Department of Public Health, Section of Environmental Health, University of Copenhagen, Denmark
| | - Steffen Loft
- Faculty of Health and Medical Science, Department of Public Health, Section of Environmental Health, University of Copenhagen, Denmark
| | - Peter Møller
- Faculty of Health and Medical Science, Department of Public Health, Section of Environmental Health, University of Copenhagen, Denmark
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40
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Lorge E, Moore MM, Clements J, O'Donovan M, Fellows MD, Honma M, Kohara A, Galloway S, Armstrong MJ, Thybaud V, Gollapudi B, Aardema MJ, Tanir JY. Standardized cell sources and recommendations for good cell culture practices in genotoxicity testing. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2016; 809:1-15. [PMID: 27692294 DOI: 10.1016/j.mrgentox.2016.08.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 07/29/2016] [Accepted: 08/02/2016] [Indexed: 11/16/2022]
Abstract
Good cell culture practice and characterization of the cell lines used are of critical importance in in vitro genotoxicity testing. The objective of this initiative was to make continuously available stocks of the characterized isolates of the most frequently used mammalian cell lines in genotoxicity testing anywhere in the world ('IVGT' cell lines). This project was organized under the auspices of the International Life Sciences Institute (ILSI) Health and Environmental Sciences Institute (HESI) Project Committee on the Relevance and Follow-up of Positive Results in In Vitro Genetic Toxicity (IVGT) Testing. First, cell isolates were identified that are as close as possible to the isolate described in the initial publications reporting their use in genotoxicity testing. The depositors of these cell lines managed their characterization and their expansion for preparing continuously available stocks of these cells that are stored at the European Collection of Cell Cultures (ECACC, UK) and the Japanese Collection of Research Bioresources (JCRB, Japan). This publication describes how the four 'IVGT' cell lines, i.e. L5178Y TK+/- 3.7.2C, TK6, CHO-WBL and CHL/IU, were prepared for deposit at the ECACC and JCRB cell banks. Recommendations for handling these cell lines and monitoring their characteristics are also described. The growth characteristics of these cell lines (growth rates and cell cycles), their identity (karyotypes and genetic status) and ranges of background frequencies of select endpoints are also reported to help in the routine practice of genotoxicity testing using these cell lines.
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Affiliation(s)
- E Lorge
- Servier Group, 45520, Gidy, France
| | - M M Moore
- Ramboll Environ, Little Rock, AR, 72201, USA
| | - J Clements
- Covance Laboratories Ltd, Harrogate, HG3 1PY, UK
| | - M O'Donovan
- O'Donovan GT Consulting Ltd., Epperstone, Nottingham, NG14 6AG, UK
| | - M D Fellows
- AstraZeneca, Drug Safety and Metabolism, Cambridge, CB4 0WG, UK
| | - M Honma
- National Institute of Health Sciences, Tokyo, Japan
| | - A Kohara
- JCRB Cell Bank, National Institutes of Biomedical Innovation, Health and Nutrition, Osaka, Japan
| | - S Galloway
- Merck Research Laboratories, W 45-316, West Point, PA 19486, USA
| | - M J Armstrong
- Merck Research Laboratories, W 45-316, West Point, PA 19486, USA
| | - V Thybaud
- Sanofi, 94400, Vitry sur Seine, France
| | - B Gollapudi
- Exponent, Inc., 1910 St. Andrews St., Midland, MI 48640, USA
| | - M J Aardema
- Marilyn Aardema Consulting LLC, Fairfield, OH 45014, USA
| | - J Y Tanir
- ILSI Health and Environmental Sciences Institute, Washington, DC 20005, USA.
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41
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Fujita Y, Morita T, Matsumura S, Kawamoto T, Ito Y, Nishiyama N, Honda H. Comprehensive retrospective evaluation of existing in vitro chromosomal aberration test data by cytotoxicity index transformation. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2016; 802:38-49. [DOI: 10.1016/j.mrgentox.2016.03.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 03/21/2016] [Accepted: 03/21/2016] [Indexed: 01/28/2023]
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42
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Yauk CL, Buick JK, Williams A, Swartz CD, Recio L, Li H, Fornace AJ, Thomson EM, Aubrecht J. Application of the TGx-28.65 transcriptomic biomarker to classify genotoxic and non-genotoxic chemicals in human TK6 cells in the presence of rat liver S9. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2016; 57:243-60. [PMID: 26946220 PMCID: PMC5021161 DOI: 10.1002/em.22004] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 02/03/2016] [Accepted: 02/04/2016] [Indexed: 05/05/2023]
Abstract
In vitro transcriptional signatures that predict toxicities can facilitate chemical screening. We previously developed a transcriptomic biomarker (known as TGx-28.65) for classifying agents as genotoxic (DNA damaging) and non-genotoxic in human lymphoblastoid TK6 cells. Because TK6 cells do not express cytochrome P450s, we confirmed accurate classification by the biomarker in cells co-exposed to 1% 5,6 benzoflavone/phenobarbital-induced rat liver S9 for metabolic activation. However, chemicals may require different types of S9 for activation. Here we investigated the response of TK6 cells to higher percentages of Aroclor-, benzoflavone/phenobarbital-, or ethanol-induced rat liver S9 to expand TGx-28.65 biomarker applicability. Transcriptional profiles were derived 3 to 4 hr following a 4 hr co-exposure of TK6 cells to test chemicals and S9. Preliminary studies established that 10% Aroclor- and 5% ethanol-induced S9 alone did not induce the TGx-28.65 biomarker genes. Seven genotoxic and two non-genotoxic chemicals (and concurrent solvent and positive controls) were then tested with one of the S9s (selected based on cell survival and micronucleus induction). Relative survival and micronucleus frequency was assessed by flow cytometry in cells 20 hr post-exposure. Genotoxic/non-genotoxic chemicals were accurately classified using the different S9s. One technical replicate of cells co-treated with dexamethasone and 10% Aroclor-induced S9 was falsely classified as genotoxic, suggesting caution in using high S9 concentrations. Even low concentrations of genotoxic chemicals (those not causing cytotoxicity) were correctly classified, demonstrating that TGx-28.65 is a sensitive biomarker of genotoxicity. A meta-analysis of datasets from 13 chemicals supports that different S9s can be used in TK6 cells, without impairing classification using the TGx-28.65 biomarker.
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Affiliation(s)
- Carole L. Yauk
- Environmental Health Science and Research Bureau, Health CanadaOttawaOntarioCanada
| | - Julie K. Buick
- Environmental Health Science and Research Bureau, Health CanadaOttawaOntarioCanada
| | - Andrew Williams
- Environmental Health Science and Research Bureau, Health CanadaOttawaOntarioCanada
| | - Carol D. Swartz
- Integrated Laboratory Systems IncResearch Triangle ParkNorth Carolina
| | - Leslie Recio
- Integrated Laboratory Systems IncResearch Triangle ParkNorth Carolina
| | - Heng‐Hong Li
- Department of Biochemistry and Molecular and Cellular BiologyGeorgetown University Medical CenterWashingtonDistrict of Columbia
- Department of OncologyGeorgetown University Medical CenterWashingtonDistrict of Columbia
| | - Albert J. Fornace
- Department of Biochemistry and Molecular and Cellular BiologyGeorgetown University Medical CenterWashingtonDistrict of Columbia
- Department of OncologyGeorgetown University Medical CenterWashingtonDistrict of Columbia
| | - Errol M. Thomson
- Environmental Health Science and Research Bureau, Health CanadaOttawaOntarioCanada
| | - Jiri Aubrecht
- Drug Safety Research and Development, Pfizer IncGrotonConnecticut
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43
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Ates G, Raitano G, Heymans A, Van Bossuyt M, Vanparys P, Mertens B, Chesne C, Roncaglioni A, Milushev D, Benfenati E, Rogiers V, Doktorova TY. In silico tools and transcriptomics analyses in the mutagenicity assessment of cosmetic ingredients: a proof-of-principle on how to add weight to the evidence. Mutagenesis 2016; 31:453-61. [PMID: 26980085 DOI: 10.1093/mutage/gew008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Prior to the downstream development of chemical substances, including pharmaceuticals and cosmetics, their influence on the genetic apparatus has to be tested. Several in vitro and in vivo assays have been developed to test for genotoxicity. In a first tier, a battery of two to three in vitro tests is recommended to cover mutagenicity, clastogenicity and aneugenicity as main endpoints. This regulatory in vitro test battery is known to have a high sensitivity, which is at the expense of the specificity. The high number of false positive in vitro results leads to excessive in vivo follow-up studies. In the case of cosmetics it may even induce the ban of the particular compound since in Europe the use of experimental animals is no longer allowed for cosmetics. In this article, an alternative approach to derisk a misleading positive Ames test is explored. Hereto we first tested the performance of five existing computational tools to predict the potential mutagenicity of a data set of 132 cosmetic compounds with a known genotoxicity profile. Furthermore, we present, as a proof-of-principle, a strategy in which a combination of computational tools and mechanistic information derived from in vitro transcriptomics analyses is used to derisk a misleading positive Ames test result. Our data shows that this strategy may represent a valuable tool in a weight-of-evidence approach to further evaluate a positive outcome in an Ames test.
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Affiliation(s)
| | - Giuseppa Raitano
- IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156 Milan, Italy
| | | | - Melissa Van Bossuyt
- Unit of Toxicology, Scientific Institute of Public Health (WIV-ISP), Juliette Wytsmanstraat 14, B-1050, Brussels, Belgium
| | | | - Birgit Mertens
- Unit of Toxicology, Scientific Institute of Public Health (WIV-ISP), Juliette Wytsmanstraat 14, B-1050, Brussels, Belgium
| | - Christophe Chesne
- Biopredic International, Parc d'activité de la Bretèche Bâtiment A4, 35760 Saint Grégoire, France and
| | - Alessandra Roncaglioni
- IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156 Milan, Italy
| | | | - Emilio Benfenati
- IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156 Milan, Italy
| | | | - Tatyana Y Doktorova
- Unit of Toxicology, Scientific Institute of Public Health (WIV-ISP), Juliette Wytsmanstraat 14, B-1050, Brussels, Belgium
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44
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Fujita Y, Kasamatsu T, Ikeda N, Nishiyama N, Honda H. A retrospective evaluation method for in vitro mammalian genotoxicity tests using cytotoxicity index transformation formulae. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2016; 796:1-7. [PMID: 26778504 DOI: 10.1016/j.mrgentox.2015.11.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 07/21/2015] [Accepted: 11/18/2015] [Indexed: 10/22/2022]
Abstract
Although in vitro chromosomal aberration tests and micronucleus tests have been widely used for genotoxicity evaluation, false-positive results have been reported under strong cytotoxic conditions. To reduce false-positive results, the new Organization for Economic Co-operation and Development (OECD) test guideline (TG) recommends the use of a new cytotoxicity index, relative increase in cell count or relative population doubling (RICC/RPD), instead of the traditionally used index, relative cell count (RCC). Although the use of the RICC/RPD may result in different outcomes and require re-evaluation of tested substances, it is impractical to re-evaluate all existing data. Therefore, we established a method to estimate test results from existing RCC data. First, we developed formulae to estimate RICC/RPD from RCC without cell counts by considering cell doubling time and experiment time. Next, the accuracy of the cytotoxicity index transformation formulae was verified by comparing estimated RICC/RPD and measured RICC/RPD for 3 major chemicals associated with false-positive genotoxicity test results: ethyl acrylate, eugenol and p-nitrophenol. Moreover, 25 compounds with false-positive in vitro chromosomal aberration (CA) test results were re-evaluated to establish a retrospective evaluation method based on derived estimated RICC/RPD values. The estimated RICC/RPD values were in good agreement with the measured RICC/RPD values for every concentration and chemical, and the estimated RICC suggested the possibility that 12 chemicals (48%) with previously judged false-positive results in fact had negative results. Our method enables transformation of RCC data into RICC/RPD values with a high degree of accuracy and will facilitate comprehensive retrospective evaluation of test results.
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Affiliation(s)
- Yurika Fujita
- R&D Safety Science Research, Kao Corporation, 2606 Akabane, Ichikai-Machi, Haga-Gun, Tochigi 321-3497, Japan
| | - Toshio Kasamatsu
- R&D Safety Science Research, Kao Corporation, 2606 Akabane, Ichikai-Machi, Haga-Gun, Tochigi 321-3497, Japan
| | - Naohiro Ikeda
- R&D Safety Science Research, Kao Corporation, 2606 Akabane, Ichikai-Machi, Haga-Gun, Tochigi 321-3497, Japan
| | - Naohiro Nishiyama
- R&D Safety Science Research, Kao Corporation, 2606 Akabane, Ichikai-Machi, Haga-Gun, Tochigi 321-3497, Japan
| | - Hiroshi Honda
- R&D Safety Science Research, Kao Corporation, 2606 Akabane, Ichikai-Machi, Haga-Gun, Tochigi 321-3497, Japan.
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Verbist BMP, Verheyen GR, Vervoort L, Crabbe M, Beerens D, Bosmans C, Jaensch S, Osselaer S, Talloen W, Van den Wyngaert I, Van Hecke G, Wuyts D, Van Goethem F, Göhlmann HWH. Integrating High-Dimensional Transcriptomics and Image Analysis Tools into Early Safety Screening: Proof of Concept for a New Early Drug Development Strategy. Chem Res Toxicol 2015; 28:1914-25. [DOI: 10.1021/acs.chemrestox.5b00103] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Dirk Wuyts
- Janssen R&D, Turnhoutseweg 30, 2340 Beerse, Belgium
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Bailey LA, Nascarella MA, Kerper LE, Rhomberg LR. Hypothesis-based weight-of-evidence evaluation and risk assessment for naphthalene carcinogenesis. Crit Rev Toxicol 2015; 46:1-42. [PMID: 26202831 PMCID: PMC4732411 DOI: 10.3109/10408444.2015.1061477] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 06/09/2015] [Indexed: 11/13/2022]
Abstract
Inhalation of naphthalene causes olfactory epithelial nasal tumors in rats (but not in mice) and benign lung adenomas in mice (but not in rats). The limited available human data have not identified an association between naphthalene exposure and increased respiratory cancer risk. Assessing naphthalene's carcinogenicity in humans, therefore, depends entirely on experimental evidence from rodents. We evaluated the respiratory carcinogenicity of naphthalene in rodents, and its potential relevance to humans, using our Hypothesis-Based Weight-of-Evidence (HBWoE) approach. We systematically and comparatively reviewed data relevant to key elements in the hypothesized modes of action (MoA) to determine which is best supported by the available data, allowing all of the data from each realm of investigation to inform interpretation of one another. Our analysis supports a mechanism that involves initial metabolism of naphthalene to the epoxide, followed by GSH depletion, cytotoxicity, chronic inflammation, regenerative hyperplasia, and tumor formation, with possible weak genotoxicity from downstream metabolites occurring only at high cytotoxic doses, strongly supporting a non-mutagenic threshold MoA in the rat nose. We also conducted a dose-response analysis, based on the likely MoA, which suggests that the rat nasal MoA is not relevant in human respiratory tissues at typical environmental exposures. Our analysis illustrates how a thorough WoE evaluation can be used to support a MoA, even when a mechanism of action cannot be fully elucidated. A non-mutagenic threshold MoA for naphthalene-induced rat nasal tumors should be considered as a basis to determine human relevance and to guide regulatory and risk-management decisions.
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Frötschl R. Experiences with the in vivo and in vitro comet assay in regulatory testing. Mutagenesis 2015; 30:51-7. [PMID: 25527728 DOI: 10.1093/mutage/geu069] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The in vivo comet assay has recently been implemented into regulatory genotoxicity testing of pharmaceuticals with inclusion into the ICH S2R1 guidance. Regulatory genotoxicity testing aims to detect DNA alterations in form of gene mutations, larger scale chromosomal damage and recombination and aneuploidy. The ICH S2R1 guideline offers two options of standard batteries of tests for the detection of these endpoints. Both options start with an AMES assay and option 1 includes an in vitro mammalian cell assay and an in vivo micronucleus assay in rodent, whereas option 2 includes an in vivo micronucleus assay in bone marrow in rodent and a second in vivo assay in a second tissue with a second endpoint. The test recommended as second in vivo test is the comet assay in rat liver. The in vivo comet assay is considered as mature enough to ensure reliable detection of relevant in vivo genotoxicants in combination with the micronucleus test in bone marrow and the AMES assay. Although lots of research papers have been published using the in vitro comet assay, the in vitro version has not been implemented into official regulatory testing guidelines. A survey of the years 1999-2014 revealed 27 in vivo comet assays submitted to BfArM with market authorisation procedures, European and national advice procedures and clinical trial applications. In three procedures, in vitro comet assays had been submitted within the genetic toxicology packages.
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Affiliation(s)
- Roland Frötschl
- BfArM-Bundesinstitut für Arzneimittel und Medizinprodukte, Federal Institute for Drugs and Medical Devices, Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
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Pradeep P, Povinelli RJ, Merrill SJ, Bozdag S, Sem DS. Novel Uses of In Vitro Data to Develop Quantitative Biological Activity Relationship Models for in Vivo Carcinogenicity Prediction. Mol Inform 2015; 34:236-45. [PMID: 27490169 DOI: 10.1002/minf.201400168] [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] [Received: 11/16/2014] [Accepted: 02/24/2015] [Indexed: 01/06/2023]
Abstract
The availability of large in vitro datasets enables better insight into the mode of action of chemicals and better identification of potential mechanism(s) of toxicity. Several studies have shown that not all in vitro assays can contribute as equal predictors of in vivo carcinogenicity for development of hybrid Quantitative Structure Activity Relationship (QSAR) models. We propose two novel approaches for the use of mechanistically relevant in vitro assay data in the identification of relevant biological descriptors and development of Quantitative Biological Activity Relationship (QBAR) models for carcinogenicity prediction. We demonstrate that in vitro assay data can be used to develop QBAR models for in vivo carcinogenicity prediction via two case studies corroborated with firm scientific rationale. The case studies demonstrate the similarities between QBAR and QSAR modeling in: (i) the selection of relevant descriptors to be used in the machine learning algorithm, and (ii) the development of a computational model that maps chemical or biological descriptors to a toxic endpoint. The results of both the case studies show: (i) improved accuracy and sensitivity which is especially desirable under regulatory requirements, and (ii) overall adherence with the OECD/REACH guidelines. Such mechanism based models can be used along with QSAR models for prediction of mechanistically complex toxic endpoints.
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Affiliation(s)
- Prachi Pradeep
- Department of Mathematics, Computer Science and Statistics, Marquette University, 1313 W. Wisconsin Avenue, Milwaukee, WI 53233, USA fax: (414) 288-5472.
| | - Richard J Povinelli
- Department of Electrical and Computer Engineering, Marquette University, 1515 W. Wisconsin Avenue, Milwaukee, WI 53233, USA
| | - Stephen J Merrill
- Department of Mathematics, Computer Science and Statistics, Marquette University, 1313 W. Wisconsin Avenue, Milwaukee, WI 53233, USA fax: (414) 288-5472
| | - Serdar Bozdag
- Department of Mathematics, Computer Science and Statistics, Marquette University, 1313 W. Wisconsin Avenue, Milwaukee, WI 53233, USA fax: (414) 288-5472
| | - Daniel S Sem
- School of Pharmacy, Concordia University Wisconsin, 12800 N. Lake Shore Drive, Mequon, WI 53097, USA
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Palermo GD, Neri QV, Cozzubbo T, Rosenwaks Z. Perspectives on the assessment of human sperm chromatin integrity. Fertil Steril 2014; 102:1508-17. [DOI: 10.1016/j.fertnstert.2014.10.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 10/02/2014] [Accepted: 10/06/2014] [Indexed: 12/13/2022]
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50
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van der Leede BJ, Doherty A, Guérard M, Howe J, O’Donovan M, Plappert-Helbig U, Thybaud V. Performance and data interpretation of the in vivo comet assay in pharmaceutical industry: EFPIA survey results. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2014; 775-776:81-8. [DOI: 10.1016/j.mrgentox.2014.09.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 09/23/2014] [Indexed: 11/27/2022]
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