1
|
Chapman KE, Shah UK, Fletcher JF, Johnson GE, Doak SH, Jenkins GJS. An integrated in vitro carcinogenicity test that distinguishes between genotoxic carcinogens, non-genotoxic carcinogens, and non-carcinogens. Mutagenesis 2024; 39:69-77. [PMID: 38301659 DOI: 10.1093/mutage/geae004] [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: 12/13/2023] [Accepted: 01/29/2024] [Indexed: 02/03/2024] Open
Abstract
Chemical safety testing plays a crucial role in product and pharmacological development, as well as chemoprevention; however, in vitro genotoxicity safety tests do not always accurately predict the chemicals that will be in vivo carcinogens. If chemicals test positive in vitro for genotoxicity but negative in vivo, this can contribute to unnecessary testing in animals used to confirm erroneous in vitro positive results. Current in vitro tests typically evaluate only genotoxicity endpoints, which limits their potential to detect non-genotoxic carcinogens. The frequency of misleading in vitro positive results can be high, leading to a requirement for more informative in vitro tests. It is now recognized that multiple-endpoint genotoxicity testing may aid more accurate detection of carcinogens and non-carcinogens. The objective of this review was to evaluate the utility of our novel, multiple-endpoint in vitro test, which uses multiple cancer-relevant endpoints to predict carcinogenic potential. The tool assessed micronucleus frequency, p53 expression, p21 expression, mitochondrial respiration, cell cycle abnormalities and, uniquely, cell morphology changes in human lymphoblastoid cell lines, TK6 and MCL-5. The endpoints were used to observe cellular responses to 18 chemicals within the following categories: genotoxic carcinogens, non-genotoxic carcinogens, toxic non-carcinogens, and misleading in vitro positive and negative agents. The number of endpoints significantly altered for each chemical was considered, alongside the holistic Integrated Signature of Carcinogenicity score, derived from the sum of fold changes for all endpoints. Following the calculation of an overall score from these measures, carcinogens exhibited greater potency than non-carcinogens. Genotoxic carcinogens were generally more potent than non-genotoxic carcinogens. This novel approach therefore demonstrated potential for correctly predicting whether chemicals with unknown mechanism may be considered carcinogens. Overall, while further validation is recommended, the test demonstrates potential for the identification of carcinogenic compounds. Adoption of the approach could enable reduced animal use in carcinogenicity testing.
Collapse
Affiliation(s)
- Katherine E Chapman
- Institute of Life Science, Swansea University Medical School, Swansea, SA2 8PP, United Kingdom
| | - Ume-Kulsoom Shah
- Institute of Life Science, Swansea University Medical School, Swansea, SA2 8PP, United Kingdom
| | - Jessica F Fletcher
- Institute of Life Science, Swansea University Medical School, Swansea, SA2 8PP, United Kingdom
| | - George E Johnson
- Institute of Life Science, Swansea University Medical School, Swansea, SA2 8PP, United Kingdom
| | - Shareen H Doak
- Institute of Life Science, Swansea University Medical School, Swansea, SA2 8PP, United Kingdom
| | - Gareth J S Jenkins
- Institute of Life Science, Swansea University Medical School, Swansea, SA2 8PP, United Kingdom
| |
Collapse
|
2
|
Varet J, Barranger A, Crochet C, Huet S, Hogeveen K, Le Hégarat L, Fessard V. New methodological developments for testing the in vitro genotoxicity of nanomaterials: Comparison of 2D and 3D HepaRG liver cell models and classical and high throughput comet assay formats. CHEMOSPHERE 2024; 350:140975. [PMID: 38142884 DOI: 10.1016/j.chemosphere.2023.140975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 12/12/2023] [Accepted: 12/13/2023] [Indexed: 12/26/2023]
Abstract
Nanomaterials (NMs) are defined as materials with at least one external dimension below 100 nm. Their small size confers them interesting unique physico-chemical properties, hence NMs are increasingly used in a diversity of applications. However, the specific properties of NMs could also make them more harmful than their bulk counterparts. Therefore, there is a crucial need to deliver efficient NM hazard assessment in order to sustain the responsible development of nanotechnology. This study analysed the genotoxic potential of several NMs: one titanium dioxide (TiO2) and two zinc oxide NMs (ZnO) that were tested up to 100 μg/mL on 2D and 3D hepatic HepaRG models. Genotoxicity analysis was performed comparing the alkaline comet assay in classical and high throughput formats. Moreover, oxidative DNA lesions were investigated with the Fpg-modified comet assay. Results showed that TiO2 NMs were not cytotoxic and not genotoxic in either cell model, although a small increase in the % tail DNA was observed in 3D HepaRG cells at 100 μg/mL in the classical format. The two ZnO NMs (ZnO S. NMs a commercial suspension and NM110 provided by the European Union Joint Research Centre) induced a concentration-dependent increase in cytotoxicity that was more pronounced in the 2D (>20% cytotoxicity was observed for ZnO S. at concentrations greater than 25 μg/mL, and for NM 110 at 50 μg/mL) than in the 3D model (more than 20% cytotoxicity for ZnO S. NMs at 50 μg/mL). While ZnO S. NMs induced DNA damage associated with cytotoxicity (at 25 and 50 μg/mL in 2D and 50 μg/mL in 3D), NM110 showed a clear genotoxic effect at non-cytotoxic concentrations (25 μg/mL in 2D and at 25 and 50 μg/mL in 3D). No major differences could be observed in the comet assay in the presence or absence of the Fpg enzyme. High throughput analysis using CometChip® mostly confirmed the results obtained with the classical format, and even enhanced the detection of genotoxicity in the 3D model. In conclusion, this study demonstrated that new approach methodologies (NAMs), 3D models and the high throughput format for the comet assay, were more efficient in the detection of genotoxic effects, and are therefore promising approaches to improve hazard assessment of NMs.
Collapse
Affiliation(s)
- Julia Varet
- French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Fougères Laboratory, Toxicology of Contaminants Unit, Fougères, France.
| | - Audrey Barranger
- French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Fougères Laboratory, Toxicology of Contaminants Unit, Fougères, France
| | - Camille Crochet
- French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Fougères Laboratory, Toxicology of Contaminants Unit, Fougères, France
| | - Sylvie Huet
- French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Fougères Laboratory, Toxicology of Contaminants Unit, Fougères, France
| | - Kevin Hogeveen
- French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Fougères Laboratory, Toxicology of Contaminants Unit, Fougères, France
| | - Ludovic Le Hégarat
- French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Fougères Laboratory, Toxicology of Contaminants Unit, Fougères, France
| | - Valérie Fessard
- French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Fougères Laboratory, Toxicology of Contaminants Unit, Fougères, France.
| |
Collapse
|
3
|
Mishra N, Srivastava R. Bacterial worth in genotoxicity assessment studies. J Microbiol Methods 2023; 215:106860. [PMID: 38008307 DOI: 10.1016/j.mimet.2023.106860] [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: 10/16/2023] [Revised: 11/18/2023] [Accepted: 11/19/2023] [Indexed: 11/28/2023]
Abstract
Bacterial-based genotoxicity test systems play a significant role in the detection and evaluation of genotoxicity in vitro and have gained importance due to attributes like wide applicability, speed, high sensitivity, good reproducibility, and simplicity. The Salmonella microsomal mutagenicity assay was created by Ames and colleagues at the beginning of the 1970s, and it was based on the fundamental notion that in auxotrophic bacterial strains with inhibited growth, a mutant gene would revert to its original state on exposure to genotoxicants. This is the most successful and widely used in vitro genotoxicity test. Later, a number of additional test systems that incorporated DNA repair mechanisms including the bacterial SOS response were created. Genetic engineering has further provided significant advancement in these test systems with the development of highly sophisticated bacterial tester strains with significantly increased sensitivity to evaluate the chemical nature of hazardous substances and pollutants. These bacterial bioassays render an opportunity to detect the defined effects of compounds at the molecular level. In this review, all the aspects related to the bacterial system in genotoxicity assessment have been summarized and their role is elaborated concerning real-time requirements and future perspectives.
Collapse
Affiliation(s)
- Nidhi Mishra
- Department of Zoology, University of Lucknow, Lucknow, U.P. 226007, India.
| | - Rashmi Srivastava
- Department of Zoology, Babasaheb Bhimrao Ambedkar University, Lucknow, U.P. 226025, India
| |
Collapse
|
4
|
Møller P, Roursgaard M. Exposure to nanoplastic particles and DNA damage in mammalian cells. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2023; 792:108468. [PMID: 37666295 DOI: 10.1016/j.mrrev.2023.108468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 08/30/2023] [Accepted: 08/30/2023] [Indexed: 09/06/2023]
Abstract
There is concern about human exposure to nanoplastics from intentional use or degradation of plastics in the environment. This review assesses genotoxic effects of nanoplastics, defined as particles with a primary size of less than 1000 nm. The majority of results on genotoxicity come from studies on polystyrene (PS) particles in mammalian cell cultures. Most studies have measured DNA strand breaks (standard comet assay), oxidatively damaged DNA (Fpg-modified comet assay) and micronuclei. Twenty-nine out of 60 results have shown statistically significant genotoxic effects by PS exposure in cell cultures. A statistical analysis indicates that especially modified PS particles are genotoxic (odds ratio = 8.6, 95 % CI: 1.6, 46) and immune cells seems to be more sensitive to genotoxicity than other cell types such as epithelial cells (odds ratio = 8.0, 95 % CI: 1.6, 39). On the contrary, there is not a clear association between statistically significant effects in genotoxicity tests and the primary size of PS particles, (i.e. smaller versus larger than 100 nm) or between the type of genotoxic endpoint (i.e. repairable versus permanent DNA lesions). Three studies of PS particle exposure in animals have shown increased level of DNA strand breaks in leukocytes and prefrontal cortex cells. Nanoplastics from polyethylene, propylene, polyvinyl chloride and polyethylene terephthalate have been investigated in very few studies and it is currently not possible to draw conclusion about their genotoxic hazard. In summary, there is some evidence suggesting that PS particles may be genotoxic in mammalian cells.
Collapse
Affiliation(s)
- Peter Møller
- Department of Public Health, Section of Environmental Health, University of Copenhagen, Øster Farimagsgade 5A, DK-1014 Copenhagen K, Denmark.
| | - Martin Roursgaard
- Department of Public Health, Section of Environmental Health, University of Copenhagen, Øster Farimagsgade 5A, DK-1014 Copenhagen K, Denmark
| |
Collapse
|
5
|
Dirven Y, Eide DM, Henriksson EW, Hjorth R, Sharma AK, Graupner A, Brunborg G, Ballangby J, Boisen AMZ, Swedmark S, Gützkow KB, Olsen AK. Assessing testicular germ cell DNA damage in the comet assay; introduction of a proof-of-concept. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2023; 64:88-104. [PMID: 36629742 DOI: 10.1002/em.22527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 12/30/2022] [Accepted: 01/06/2023] [Indexed: 06/17/2023]
Abstract
The in vivo comet assay is widely used to measure genotoxicity; however, the current OECD test guideline (TG 489) does not recommend using the assay to assess testicular germ cells, due to the presence of testicular somatic cells. An adapted approach to specifically assess testicular germ cells within the comet assay is certainly warranted, considering regulatory needs for germ cell-specific genotoxicity data in relation to the increasing global production of and exposure to potentially hazardous chemicals. Here, we provide a proof-of-concept to selectively analyze round spermatids and primary spermatocytes, distinguishing them from other cells of the testicle. Utilizing the comet assay recordings of DNA content (total fluorescence intensity) and DNA damage (% tail intensity) of individual comets, we developed a framework to distinguish testicular cell populations based on differences in DNA content/ploidy and appearance. Haploid round spermatid comets are identified through (1) visual inspection of DNA content distributions, (2) setting DNA content thresholds, and (3) modeling DNA content distributions using a normal mixture distribution function. We also describe an approach to distinguish primary spermatocytes during comet scoring, based on their high DNA content and large physical size. Our concept allows both somatic and germ cells to be analyzed in the same animal, adding a versatile, sensitive, rapid, and resource-efficient assay to the limited genotoxicity assessment toolbox for germ cells. An adaptation of TG 489 facilitates accumulation of valuable information regarding distribution of substances to germ cells and their potential for inducing germ cell gene mutations and structural chromosomal aberrations.
Collapse
Affiliation(s)
- Yvette Dirven
- Norwegian Institute of Public Health, Division of Climate and Environmental Health, Oslo, Norway
- Centre for Environmental Radioactivity (CERAD, Centre of Excellence of the Norwegian Research Council), Oslo, Norway
| | - Dag Markus Eide
- Norwegian Institute of Public Health, Division of Climate and Environmental Health, Oslo, Norway
- Centre for Environmental Radioactivity (CERAD, Centre of Excellence of the Norwegian Research Council), Oslo, Norway
| | - Erika Witasp Henriksson
- Swedish Chemicals Agency, Department of Development of Legislation and Other Instruments, Unit of Proposals for Classification and Restriction, Sundbyberg, Sweden
- Swedish Chemicals Agency, Department of Development of Legislation and Other Instruments, Unit of Evaluation of Substances, Sundbyberg, Sweden
| | - Rune Hjorth
- The Danish Environmental Protection Agency, Odense, Denmark
| | - Anoop Kumar Sharma
- Technical University of Denmark, National Food Institute, Lyngby, Denmark
| | - Anne Graupner
- Norwegian Institute of Public Health, Division of Climate and Environmental Health, Oslo, Norway
- Centre for Environmental Radioactivity (CERAD, Centre of Excellence of the Norwegian Research Council), Oslo, Norway
| | - Gunnar Brunborg
- Norwegian Institute of Public Health, Division of Climate and Environmental Health, Oslo, Norway
- Centre for Environmental Radioactivity (CERAD, Centre of Excellence of the Norwegian Research Council), Oslo, Norway
| | - Jarle Ballangby
- Norwegian Institute of Public Health, Division of Climate and Environmental Health, Oslo, Norway
- Centre for Environmental Radioactivity (CERAD, Centre of Excellence of the Norwegian Research Council), Oslo, Norway
| | | | - Stellan Swedmark
- Swedish Chemicals Agency, Department of Development of Legislation and Other Instruments, Unit of Evaluation of Substances, Sundbyberg, Sweden
| | - Kristine Bjerve Gützkow
- Norwegian Institute of Public Health, Division of Climate and Environmental Health, Oslo, Norway
- Centre for Environmental Radioactivity (CERAD, Centre of Excellence of the Norwegian Research Council), Oslo, Norway
| | - Ann-Karin Olsen
- Norwegian Institute of Public Health, Division of Climate and Environmental Health, Oslo, Norway
- Centre for Environmental Radioactivity (CERAD, Centre of Excellence of the Norwegian Research Council), Oslo, Norway
| |
Collapse
|
6
|
Habil MR, Salazar-González RA, Doll MA, Hein DW. N-acetyltransferase 2 acetylator genotype-dependent N-acetylation and toxicity of the arylamine carcinogen β-naphthylamine in cryopreserved human hepatocytes. Arch Toxicol 2022; 96:3257-3263. [PMID: 36112171 PMCID: PMC9641657 DOI: 10.1007/s00204-022-03381-4] [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: 08/29/2022] [Accepted: 09/08/2022] [Indexed: 11/02/2022]
Abstract
We used cryopreserved human hepatocytes that express rapid, intermediate, and slow acetylator N-acetyltransferase 2 (NAT2) genotypes to measure the N-acetylation of β-naphthylamine (BNA) which is one of the aromatic amines found in cigarette smoke including E-cigarettes. We investigated the role of NAT2 genetic polymorphism in genotoxicity and oxidative stress induced by BNA. In vitro BNA NAT2 activities in rapid acetylators was 1.6 and 3.5-fold higher than intermediate (p < 0.01) and slow acetylators (p < 0.0001). BNA N-acetylation in situ was 3 to 4- fold higher in rapid acetylators than slow acetylators, following incubation with 10 and 100 µM BNA (p < 0.01). DNA damage was two to threefold higher in the rapid versus slow acetylators (p < 0.0001) and 2.5-fold higher in intermediate versus slow acetylators following BNA treatment at 100 and 1000 μM, ROS/RNS level was the highest in rapid acetylators followed by intermediate and then slow acetylators (p < 0.0001). Our findings show that the N-acetylation of BNA is NAT2 genotype dependent in cryopreserved human hepatocytes and our data further document an important role for NAT2 genetic polymorphism in modifying BNA-induced genotoxicity and oxidative damage.
Collapse
Affiliation(s)
- Mariam R Habil
- Department of Pharmacology and Toxicology, School of Medicine, University of Louisville, 505 S. Hancock Street, CTR Rm 303, Louisville, KY, 40202, USA
| | - Raúl A Salazar-González
- Department of Pharmacology and Toxicology, School of Medicine, University of Louisville, 505 S. Hancock Street, CTR Rm 303, Louisville, KY, 40202, USA
| | - Mark A Doll
- Department of Pharmacology and Toxicology, School of Medicine, University of Louisville, 505 S. Hancock Street, CTR Rm 303, Louisville, KY, 40202, USA
| | - David W Hein
- Department of Pharmacology and Toxicology, School of Medicine, University of Louisville, 505 S. Hancock Street, CTR Rm 303, Louisville, KY, 40202, USA.
| |
Collapse
|
7
|
Doak SH, Clift MJD, Costa A, Delmaar C, Gosens I, Halappanavar S, Kelly S, Pejinenburg WJGM, Rothen-Rutishauser B, Schins RPF, Stone V, Tran L, Vijver MG, Vogel U, Wohlleben W, Cassee FR. The Road to Achieving the European Commission's Chemicals Strategy for Nanomaterial Sustainability-A PATROLS Perspective on New Approach Methodologies. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2200231. [PMID: 35324067 DOI: 10.1002/smll.202200231] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/17/2022] [Indexed: 06/14/2023]
Abstract
The European Green Deal outlines ambitions to build a more sustainable, climate neutral, and circular economy by 2050. To achieve this, the European Commission has published the Chemicals Strategy for Sustainability: Towards a Toxic-Free Environment, which provides targets for innovation to better protect human and environmental health, including challenges posed by hazardous chemicals and animal testing. The European project PATROLS (Physiologically Anchored Tools for Realistic nanOmateriaL hazard aSsessment) has addressed multiple aspects of the Chemicals Strategy for Sustainability by establishing a battery of new approach methodologies, including physiologically anchored human and environmental hazard assessment tools to evaluate the safety of engineered nanomaterials. PATROLS has delivered and improved innovative tools to support regulatory decision-making processes. These tools also support the need for reducing regulated vertebrate animal testing; when used at an early stage of the innovation pipeline, the PATROLS tools facilitate the safe and sustainable development of new nano-enabled products before they reach the market.
Collapse
Affiliation(s)
- Shareen H Doak
- Swansea University Medical School, Singleton Park, Swansea, SA2 8PP, UK
| | - Martin J D Clift
- Swansea University Medical School, Singleton Park, Swansea, SA2 8PP, UK
| | - Anna Costa
- Institute of Science and Technology for Ceramics, CNR-ISTEC-National Research Council of Italy, Faenza, Italy
| | - Christiaan Delmaar
- National Institute for Public Health and the Environment Netherlands, PO box 1, Bilthoven, 3720, the Netherlands
| | - Ilse Gosens
- National Institute for Public Health and the Environment Netherlands, PO box 1, Bilthoven, 3720, the Netherlands
| | - Sabina Halappanavar
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, K1A0K9, Canada
| | - Sean Kelly
- Nanotechnology Industries Association, Avenue Tervueren 143, Brussels, 1150, Belgium
| | - Willie J G M Pejinenburg
- National Institute for Public Health and the Environment Netherlands, PO box 1, Bilthoven, 3720, the Netherlands
- Leiden University, PO Box 9518, Leiden, 2300 RA, the Netherlands
| | | | - Roel P F Schins
- IUF-Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225, Düsseldorf, Germany
| | - Vicki Stone
- School of Engineering and Physical Sciences, Heriot Watt University, Edinburgh, UK
| | - Lang Tran
- Institute of Occupational Medicine (IOM), Edinburgh, Scotland, EH14 4AP, UK
| | - Martina G Vijver
- Leiden University, PO Box 9518, Leiden, 2300 RA, the Netherlands
| | - Ulla Vogel
- National Research Centre for the Working Environment, Copenhagen, DK-2100, Denmark
| | - Wendel Wohlleben
- Advanced Materials Research, BASF SE, 67056, Ludwigshafen, Germany
| | - Flemming R Cassee
- National Institute for Public Health and the Environment Netherlands, PO box 1, Bilthoven, 3720, the Netherlands
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht, the Netherlands
| |
Collapse
|