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Abiola T, John EO, Sossou IT, Charles Callistus B. Immune boosting and ameliorative properties of aqueous extract of Vernonia amygdalina Delile against MSG-induced genotoxicity: An in silico and in vivo approach. Heliyon 2024; 10:e23226. [PMID: 38163244 PMCID: PMC10755317 DOI: 10.1016/j.heliyon.2023.e23226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 11/28/2023] [Accepted: 11/29/2023] [Indexed: 01/03/2024] Open
Abstract
Vernonia amygdalina (VA) is popularly consumed as food and as medicine due to its nutritional and bioactive constituents. This study assessed the anti-genotoxic effect of aqueous leaf extract of VA against monosodium (MSG) -induced genotoxicity. Crude extraction and phytochemical analysis were done using standard methods. In silico studies was done using compounds in the extract against Bcl-2, NF-kB 50, DNA polymerase lambda, DNA ligase, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX). Twelve rats were divided into three groups with four rats in each group. Group I was fed on food and water, group II received MSG (4 g/kg) per body weight (pbw) intraperitoneally, group III received MSG (4 g/kg) pbw intraperitoneally followed by oral dose of VA leaf extract (250 mg/kg) per body weight. The number of the micronucleated red blood cells and white blood cells were determined from blood smears microscopically. Results showed that aqueous extract of VA contained in mg/100 g alkaloids (7.04 ± 0.16), saponins (3.91 ± 0.13), flavonoid (1.64 ± 0.16), phenol (3.40 ± 0.12) and tannins (0.07 ± 0.32). In silico studies revealed high binding interaction (ΔG > -8.6) of vernoniosides D and E with all the tested proteins. There was a reduction in the number of micronucleated cells, neutrophils and eosinophils of the treated group compared to the MSG group, while there was an increase in the lymphocyte count. The anti-genotoxic effects of VA leaf extract might be attributed to the synergistic interaction of the various bioactive components in the extract. VA could be a potential plant for the prevention of cancer and other diseases that attenuate the immune system.
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Affiliation(s)
- Temitope Abiola
- Department of Biochemistry, Faculty of Basic Medical Sciences, Redeemer's University, Ede, Osun State, Nigeria
| | - Emmanuel O. John
- Department of Chemical Sciences, Biochemistry Unit, College of Natural and Applied Sciences, Oduduwa University, Ipetumodu, Ile-Ife, Osun State, Nigeria
| | - Ibukun Temitope Sossou
- Department of Medical Laboratory Sciences, Faculty of Basic Medical Sciences, Redeemer's University, Ede, Osun State, Nigeria
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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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Beal MA, Audebert M, Barton-Maclaren T, Battaion H, Bemis JC, Cao X, Chen C, Dertinger SD, Froetschl R, Guo X, Johnson G, Hendriks G, Khoury L, Long AS, Pfuhler S, Settivari RS, Wickramasuriya S, White P. Quantitative in vitro to in vivo extrapolation of genotoxicity data provides protective estimates of in vivo dose. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2023; 64:105-122. [PMID: 36495195 DOI: 10.1002/em.22521] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 11/29/2022] [Accepted: 11/30/2022] [Indexed: 06/17/2023]
Abstract
Genotoxicity assessment is a critical component in the development and evaluation of chemicals. Traditional genotoxicity assays (i.e., mutagenicity, clastogenicity, and aneugenicity) have been limited to dichotomous hazard classification, while other toxicity endpoints are assessed through quantitative determination of points-of-departures (PODs) for setting exposure limits. The more recent higher-throughput in vitro genotoxicity assays, many of which also provide mechanistic information, offer a powerful approach for determining defined PODs for potency ranking and risk assessment. In order to obtain relevant human dose context from the in vitro assays, in vitro to in vivo extrapolation (IVIVE) models are required to determine what dose would elicit a concentration in the body demonstrated to be genotoxic using in vitro assays. Previous work has demonstrated that application of IVIVE models to in vitro bioactivity data can provide PODs that are protective of human health, but there has been no evaluation of how these models perform with in vitro genotoxicity data. Thus, the Genetic Toxicology Technical Committee, under the Health and Environmental Sciences Institute, conducted a case study on 31 reference chemicals to evaluate the performance of IVIVE application to genotoxicity data. The results demonstrate that for most chemicals considered here (20/31), the PODs derived from in vitro data and IVIVE are health protective relative to in vivo PODs from animal studies. PODs were also protective by assay target: mutations (8/13 chemicals), micronuclei (9/12), and aneugenicity markers (4/4). It is envisioned that this novel testing strategy could enhance prioritization, rapid screening, and risk assessment of genotoxic chemicals.
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Affiliation(s)
- Marc A Beal
- Bureau of Chemical Safety, Health Products and Food Branch, Health Canada, Ottawa, Ontario, Canada
| | - Marc Audebert
- Toxalim UMR1331, Toulouse University, INRAE, Toulouse, France
| | - Tara Barton-Maclaren
- Existing Substances Risk Assessment Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada
| | - Hannah Battaion
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada
| | | | - Xuefei Cao
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas, USA
| | - Connie Chen
- Health and Environmental Sciences Institute, Washington, District of Columbia, USA
| | | | | | - Xiaoqing Guo
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas, USA
| | | | | | | | - Alexandra S Long
- Existing Substances Risk Assessment Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada
| | - Stefan Pfuhler
- Global Product Stewardship, Procter & Gamble, Cincinnati, Ohio, USA
| | - Raja S Settivari
- Mammalian Toxicology Center, Corteva Agriscience, Newark, Delaware, USA
| | - Shamika Wickramasuriya
- Existing Substances Risk Assessment Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada
| | - Paul White
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada
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Oku Y, Madia F, Lau P, Paparella M, McGovern T, Luijten M, Jacobs MN. Analyses of Transcriptomics Cell Signalling for Pre-Screening Applications in the Integrated Approach for Testing and Assessment of Non-Genotoxic Carcinogens. Int J Mol Sci 2022; 23:ijms232112718. [PMID: 36361516 PMCID: PMC9659232 DOI: 10.3390/ijms232112718] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 10/18/2022] [Accepted: 10/18/2022] [Indexed: 12/03/2022] Open
Abstract
With recent rapid advancement of methodological tools, mechanistic understanding of biological processes leading to carcinogenesis is expanding. New approach methodologies such as transcriptomics can inform on non-genotoxic mechanisms of chemical carcinogens and can be developed for regulatory applications. The Organisation for the Economic Cooperation and Development (OECD) expert group developing an Integrated Approach to the Testing and Assessment (IATA) of Non-Genotoxic Carcinogens (NGTxC) is reviewing the possible assays to be integrated therein. In this context, we review the application of transcriptomics approaches suitable for pre-screening gene expression changes associated with phenotypic alterations that underlie the carcinogenic processes for subsequent prioritisation of downstream test methods appropriate to specific key events of non-genotoxic carcinogenesis. Using case studies, we evaluate the potential of gene expression analyses especially in relation to breast cancer, to identify the most relevant approaches that could be utilised as (pre-) screening tools, for example Gene Set Enrichment Analysis (GSEA). We also consider how to address the challenges to integrate gene panels and transcriptomic assays into the IATA, highlighting the pivotal omics markers identified for assay measurement in the IATA key events of inflammation, immune response, mitogenic signalling and cell injury.
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Affiliation(s)
- Yusuke Oku
- The Organisation for Economic Cooperation and Development (OECD), 2 Rue Andre Pascal, 75016 Paris, France
- Correspondence: (Y.O.); (M.N.J.)
| | - Federica Madia
- European Commission, Joint Research Centre (JRC), Via Enrico Fermi, 2749, 21027 Ispra, Italy
| | - Pierre Lau
- Istituto Italiano di Tecnologia, 16163 Genova, Italy
| | - Martin Paparella
- Institute of Medical Biochemistry, Biocenter, Medical University of Innsbruck, Innrain 80, 6020 Innbruck, Austria
| | - Timothy McGovern
- US Food and Drug Administration (FDA), 10903 New Hampshire Avenue, Silver Spring, MD 20901, USA
| | - Mirjam Luijten
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Antonie van Leeuwenhoeklaan 9, Bilthoven, 3721 MA Utrecht, The Netherlands
| | - Miriam N. Jacobs
- Centre for Radiation, Chemical and Environmental Hazard (CRCE), Public Health England (PHE), Chilton OX11 0RQ, Oxfordshire, UK
- Correspondence: (Y.O.); (M.N.J.)
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5
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Behl T, Rachamalla M, Najda A, Sehgal A, Singh S, Sharma N, Bhatia S, Al-Harrasi A, Chigurupati S, Vargas-De-La-Cruz C, Hobani YH, Mohan S, Goyal A, Katyal T, Solarska E, Bungau S. Applications of Adductomics in Chemically Induced Adverse Outcomes and Major Emphasis on DNA Adductomics: A Pathbreaking Tool in Biomedical Research. Int J Mol Sci 2021; 22:10141. [PMID: 34576304 PMCID: PMC8467560 DOI: 10.3390/ijms221810141] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 09/04/2021] [Accepted: 09/13/2021] [Indexed: 01/06/2023] Open
Abstract
Adductomics novel and emerging discipline in the toxicological research emphasizes on adducts formed by reactive chemical agents with biological molecules in living organisms. Development in analytical methods propelled the application and utility of adductomics in interdisciplinary sciences. This review endeavors to add a new dimension where comprehensive insights into diverse applications of adductomics in addressing some of society's pressing challenges are provided. Also focuses on diverse applications of adductomics include: forecasting risk of chronic diseases triggered by reactive agents and predicting carcinogenesis induced by tobacco smoking; assessing chemical agents' toxicity and supplementing genotoxicity studies; designing personalized medication and precision treatment in cancer chemotherapy; appraising environmental quality or extent of pollution using biological systems; crafting tools and techniques for diagnosis of diseases and detecting food contaminants; furnishing exposure profile of the individual to electrophiles; and assisting regulatory agencies in risk assessment of reactive chemical agents. Characterizing adducts that are present in extremely low concentrations is an exigent task and more over absence of dedicated database to identify adducts is further exacerbating the problem of adduct diagnosis. In addition, there is scope of improvement in sample preparation methods and data processing software and algorithms for accurate assessment of adducts.
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Affiliation(s)
- Tapan Behl
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab 140401, India; (T.B.); (A.S.); (S.S.); (N.S.)
| | - Mahesh Rachamalla
- Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK S7N 5E2, Canada;
| | - Agnieszka Najda
- Department of Vegetable Crops and Medicinal Plants, University of Life Sciences in Lublin, 20-950 Lublin, Poland
| | - Aayush Sehgal
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab 140401, India; (T.B.); (A.S.); (S.S.); (N.S.)
| | - Sukhbir Singh
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab 140401, India; (T.B.); (A.S.); (S.S.); (N.S.)
| | - Neelam Sharma
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab 140401, India; (T.B.); (A.S.); (S.S.); (N.S.)
| | - Saurabh Bhatia
- Natural & Medical Sciences Research Centre, University of Nizwa, Birkat Al Mauz, Nizwa 33, Oman; (S.B.); (A.A.-H.)
| | - Ahmed Al-Harrasi
- Natural & Medical Sciences Research Centre, University of Nizwa, Birkat Al Mauz, Nizwa 33, Oman; (S.B.); (A.A.-H.)
| | - Sridevi Chigurupati
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, Qassim University, Buraydah 52571, Saudi Arabia;
| | - Celia Vargas-De-La-Cruz
- Faculty of Pharmacy and Biochemistry, Academic Department of Pharmacology, Bromatology and Toxicology, Centro Latinoamericano de Enseñanza e Investigación en Bacteriología Alimentaria, Universidad Nacional Mayor de San Marcos, Lima 15001, Peru;
- E-Health Research Center, Universidad de Ciencias y Humanidades, Lima 15001, Peru
| | - Yahya Hasan Hobani
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, Jazan University, Jazan 114, Saudi Arabia;
| | - Syam Mohan
- Substance Abuse and Toxicology Research Center, Jazan University, Jazan 114, Saudi Arabia;
| | - Amit Goyal
- GHG Khalsa College of Pharmacy, Gurusar Sadhar, Ludhiana 141104, India;
| | - Taruna Katyal
- RBMCH Division, ICMR Head Quarters, Ramalingaswami Bhawan, Ansari Nagar, New Delhi 110029, India;
| | - Ewa Solarska
- Department of Biotechnology, Microbiology and Human Nutrition, Faculty of Food Science and Biotechnology, University of Life Sciences in Lublin, 8 Skromna Street, 20-704 Lublin, Poland;
| | - Simona Bungau
- Department of Pharmacy, Faculty of Medicine and Pharmacy, University of Oradea, 410073 Oradea, Romania;
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Zhou CH, Yu CR, Huang PC, Li RW, Wang JT, Zhao TT, Zhao ZH, Ma J, Chang Y. In Vitro PIG-A Gene Mutation Assay in Human B-Lymphoblastoid TK6 Cells. PHARMACEUTICAL FRONTS 2021. [DOI: 10.1055/s-0041-1735146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
AbstractThe X-linked PIG-A gene is involved in the biosynthesis of glycosylphosphatidylinositol (GPI) anchors. PIG-A mutant cells fail to synthesize GPI and to express GPI-anchored protein markers (e.g., CD59 and CD55). In recent years, in vitro PIG-A assay has been established based on the high conservation of PIG-A/Pig-a loci among different species and the large data from the in vivo system. The purpose of this study was to extend the approach for PIG-A mutation assessment to in vitro human B-lymphoblastoid TK6 cells by detecting the loss of GPI-linked CD55 and CD59 proteins. TK6 cells were treated with three mutagens 7,12-dimethylbenz[a]anthracene (DMBA), N-ethyl-N-nitrosourea (ENU), etoposide (ETO), and two nonmutagens: cadmium chloride (CdCl2) and sodium chloride (NaCl). The mutation rate of PIG-A gene within TK6 cells was determined on the 11th day with flow cytometry analysis for the negative frequencies of CD55 and CD59. The antibodies used in this production were APC mouse-anti-human CD19 antibody, PE mouse anti-human CD55 antibody, PE mouse anti-human CD59 antibody, and nucleic acid dye 7-AAD. An immunolabeling method was used to reduce the high spontaneous level of preexisting PIG-A mutant cells. Our data suggested that DMBA-, ENU-, and ETO-induced mutation frequency of PIG-A gene was increased by twofold compared with the negative control, and the effects were dose-dependent. However, CdCl2 and NaCl did not significantly increase the mutation frequency of PIG-A gene, with a high cytotoxicity at a dose of 10 mmol/L. Our study suggested that the novel in vitro PIG-A gene mutation assay within TK6 cells may represent a complement of the present in vivo Pig-a assay, and may provide guidance for their potential use in genotoxicity even in cells with a significant deficiency of GPI anchor.
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Affiliation(s)
- Chang-Hui Zhou
- Shanghai Innostar Bio-tech Co., Ltd., China State Institute of Pharmaceutical Industry, Shanghai, People's Republic of China
| | - Chun-Rong Yu
- Shanghai Innostar Bio-tech Co., Ltd., China State Institute of Pharmaceutical Industry, Shanghai, People's Republic of China
| | - Peng-Cheng Huang
- Shanghai Innostar Bio-tech Co., Ltd., China State Institute of Pharmaceutical Industry, Shanghai, People's Republic of China
| | - Ruo-Wan Li
- Shanghai Innostar Bio-tech Co., Ltd., China State Institute of Pharmaceutical Industry, Shanghai, People's Republic of China
| | - Jing-Ting Wang
- Shanghai Innostar Bio-tech Co., Ltd., China State Institute of Pharmaceutical Industry, Shanghai, People's Republic of China
| | - Tian-Tian Zhao
- Shanghai Innostar Bio-tech Co., Ltd., China State Institute of Pharmaceutical Industry, Shanghai, People's Republic of China
| | - Ze-Hao Zhao
- Shanghai Innostar Bio-tech Co., Ltd., China State Institute of Pharmaceutical Industry, Shanghai, People's Republic of China
| | - Jing Ma
- Shanghai Innostar Bio-tech Co., Ltd., China State Institute of Pharmaceutical Industry, Shanghai, People's Republic of China
| | - Yan Chang
- Shanghai Innostar Bio-tech Co., Ltd., China State Institute of Pharmaceutical Industry, Shanghai, People's Republic of China
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Nuta O, Bouffler S, Lloyd D, Ainsbury E, Sepai O, Rothkamm K. Investigating the impact of long term exposure to chemical agents on the chromosomal radiosensitivity using human lymphoblastoid GM1899A cells. Sci Rep 2021; 11:12616. [PMID: 34135387 PMCID: PMC8209142 DOI: 10.1038/s41598-021-91957-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 05/27/2021] [Indexed: 11/09/2022] Open
Abstract
This study aimed to investigate the impact of chronic low-level exposure to chemical carcinogens with different modes of action on the cellular response to ionising radiation. Human lymphoblastoid GM1899A cells were cultured in the presence of 4-nitroquinoline N-oxide (4NQO), N-nitroso-N-methylurea (MNU) and hydrogen peroxide (H2O2) for up to 6 months at the highest non-(geno)toxic concentration identified in pilot experiments. Acute challenge doses of 1 Gy X-rays were given and chromosome damage (dicentrics, acentric fragments, micronuclei, chromatid gaps/breaks) was scored. Chronic exposure to 20 ng/ml 4NQO, 0.25 μg/ml MNU or 10 μM H2O2 hardly induced dicentrics and did not significantly alter the yield of X-ray-induced dicentrics. Significant levels of acentric fragments were induced by all chemicals, which did not change during long-term exposure. Fragment data in combined treatment samples compared to single treatments were consistent with an additive effect of chemical and radiation exposure. Low level exposure to 4NQO induced micronuclei, the yields of which did not change throughout the 6 month exposure period. As for fragments, micronuclei yields for combined treatments were consistent with an additive effect of chemical and radiation. These results suggest that cellular radiation responses are not affected by long-term low-level chemical exposure.
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Affiliation(s)
- Otilia Nuta
- Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, OX11 0RQ, Oxon, UK.
- Department of Biology, School of Sciences and Humanities, Nazarbayev University, Kabanbay Batyr 53, 01000, Nur-Sultan, Kazakhstan.
| | - Simon Bouffler
- Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, OX11 0RQ, Oxon, UK
| | - David Lloyd
- Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, OX11 0RQ, Oxon, UK
| | - Elizabeth Ainsbury
- Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, OX11 0RQ, Oxon, UK
| | - Ovnair Sepai
- Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, OX11 0RQ, Oxon, UK
| | - Kai Rothkamm
- Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, OX11 0RQ, Oxon, UK
- Department of Radiotherapy and Radiation Oncology, University Medical Center Hamburg- Eppendorf, 20246, Hamburg, Germany
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8
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Ware RE, Dertinger SD. Absence of hydroxyurea-induced mutational effects supports higher utilisation for the treatment of sickle cell anaemia. Br J Haematol 2021; 194:252-266. [PMID: 33570176 DOI: 10.1111/bjh.17323] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 12/21/2020] [Indexed: 12/21/2022]
Abstract
Hydroxyurea (hydroxycarbamide) is approved for treating both children and adults with sickle cell anaemia (SCA). Fetal haemoglobin (HbF) induction is the primary treatment response, along with improved anaemia, reduced haemolysis, myelosuppression and decreased endothelial inflammation. Hydroxyurea has proven clinical efficacy for SCA - treatment significantly reduces disease manifestations and prolongs survival. Despite these recognised benefits, long-standing concerns regarding the risks of mutagenic and potentially carcinogenic drug exposure have hampered efforts for broad hydroxyurea use in SCA, although these are based largely on outdated experimental models and treatment experiences with myeloproliferative neoplasms. Consequently, many patients with SCA are not receiving this highly effective disease-modifying therapy. In this review, we describe the concept of genotoxicity and its laboratory measurements, summarise hydroxyurea-associated data from both preclinical and clinical studies, and discuss carcinogenic potential. The genotoxicity results clearly demonstrate that hydroxyurea does not directly bind DNA and is not mutagenic. Rather, its genotoxic effects are limited to indirect clastogenicity occurring in select cell types, and only when high dose and time thresholds are exceeded. This absence of mutagenic activity is consistent with the observed lack of any compelling carcinogenic potential. Since hydroxyurea therapy for SCA carries minimal carcinogenic risks, the current drug labelling should be modified accordingly, and prescribing practices should be broadened to allow better access and increased utilisation of this highly effective drug.
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Affiliation(s)
- Russell E Ware
- Division of Hematology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,Global Health Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
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9
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Martínez-Valenzuela C, Huichapan J, Ortega LD, Irineo AB, Zenteno E, Ruiz-Ramos R. Nuclear abnormalities in umbilical cord blood lymphocytes of newborns from the Ahome and Guasave municipalities in Sinaloa, Mexico. J Obstet Gynaecol Res 2020; 47:968-977. [PMID: 33372370 DOI: 10.1111/jog.14624] [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: 01/15/2020] [Revised: 10/15/2020] [Accepted: 12/10/2020] [Indexed: 11/29/2022]
Abstract
AIM We measured the frequency of nuclear abnormalities of 210 blood samples from the umbilical cord, since human fetuses are exposed to environmental mixtures of pesticides that induce DNA damage. METHODS The determinations were made through the micronucleus assay test in lymphocytes from the umbilical cord blood of newborns whose mothers live in Ahome (n = 105) and Guasave (n = 105), Sinaloa, Mexico. RESULTS The average frequency of anomalies in 1000 cells were, respectively: micronucleus 0.4 vs. 2.9, pyknotic cells 18.3 vs. 109.2, chromatin condensation 7.7 vs. 150.1, karyolitic cells 1.8 vs. 24.4, and binucleated cells 4.9 vs. 74.6. The calculated Pearson correlation factors of nuclear abnormality frequencies between both municipalities were low and negative, suggesting that they did not correlate between the Ahome and Guasave newborns and indicating a higher number of mothers exposed in Guasave. CONCLUSION Our data suggest that monitoring nuclear abnormalities in umbilical cord blood samples could be a useful tool to identify transplacental mutagens perfusion that is being discharged into the local environment.
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Affiliation(s)
- Carmen Martínez-Valenzuela
- Institute for Research in Environment and Health, Autonomous University of Occident, Bulevar Macario Gaxiola y Carretera Internacional, Los Mochis, Sinaloa, Mexico
| | - José Huichapan
- Institute for Research in Environment and Health, Autonomous University of Occident, Bulevar Macario Gaxiola y Carretera Internacional, Los Mochis, Sinaloa, Mexico
| | - Luis Daniel Ortega
- Department of Biological Sciences, Popular Autonomous University of the State of Puebla, 13 Poniente 1927 Colonia Barrio de Santiago, Puebla, Mexico
| | - Ana Bertha Irineo
- Faculty of Medicine, Autonomous University of Occident, Bulevar Macario Gaxiola y Carretera Internacional, Los Mochis, Sinaloa, Mexico
| | - Edgar Zenteno
- Faculty of Medicine, National Autonomous University of Mexico, Ciudad Universitaria, Coyoacán, México City, Mexico
| | - Rubén Ruiz-Ramos
- Faculty of Medicine, Veracruz University, Agustín de Iturbide S/N, Zona Centro, Veracruz, Mexico
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Bline AP, Dearfield KL, DeMarini DM, Marchetti F, Yauk CL, Escher J. Heritable hazards of smoking: Applying the "clean sheet" framework to further science and policy. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:910-921. [PMID: 33064321 PMCID: PMC7756471 DOI: 10.1002/em.22412] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/26/2020] [Accepted: 10/11/2020] [Indexed: 05/06/2023]
Abstract
All the cells in our bodies are derived from the germ cells of our parents, just as our own germ cells become the bodies of our children. The integrity of the genetic information inherited from these germ cells is of paramount importance in establishing the health of each generation and perpetuating our species into the future. There is a large and growing body of evidence strongly suggesting the existence of substances that may threaten this integrity by acting as human germ cell mutagens. However, there generally are no absolute regulatory requirements to test agents for germ cell effects. In addition, the current regulatory testing paradigms do not evaluate the impacts of epigenetically mediated intergenerational effects, and there is no regulatory framework to apply new and emerging tests in regulatory decision making. At the 50th annual meeting of the Environmental Mutagenesis and Genomics Society held in Washington, DC, in September 2019, a workshop took place that examined the heritable effects of hazardous exposures to germ cells, using tobacco smoke as the example hazard. This synopsis provides a summary of areas of concern regarding heritable hazards from tobacco smoke exposures identified at the workshop and the value of the Clean Sheet framework in organizing information to address knowledge and testing gaps.
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Affiliation(s)
- Abigail P. Bline
- Fielding School of Public HealthUniversity of California Los AngelesLos AngelesCaliforniaUSA
| | | | | | - Francesco Marchetti
- Environmental Health Science Research Bureau, Health CanadaOttawaOntarioCanada
| | - Carole L. Yauk
- Department of BiologyUniversity of OttawaOttawaOntarioCanada
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11
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Smith MT, Guyton KZ, Kleinstreuer N, Borrel A, Cardenas A, Chiu WA, Felsher DW, Gibbons CF, Goodson WH, Houck KA, Kane AB, La Merrill MA, Lebrec H, Lowe L, McHale CM, Minocherhomji S, Rieswijk L, Sandy MS, Sone H, Wang A, Zhang L, Zeise L, Fielden M. The Key Characteristics of Carcinogens: Relationship to the Hallmarks of Cancer, Relevant Biomarkers, and Assays to Measure Them. Cancer Epidemiol Biomarkers Prev 2020; 29:1887-1903. [PMID: 32152214 PMCID: PMC7483401 DOI: 10.1158/1055-9965.epi-19-1346] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 01/15/2020] [Accepted: 03/04/2020] [Indexed: 12/21/2022] Open
Abstract
The key characteristics (KC) of human carcinogens provide a uniform approach to evaluating mechanistic evidence in cancer hazard identification. Refinements to the approach were requested by organizations and individuals applying the KCs. We assembled an expert committee with knowledge of carcinogenesis and experience in applying the KCs in cancer hazard identification. We leveraged this expertise and examined the literature to more clearly describe each KC, identify current and emerging assays and in vivo biomarkers that can be used to measure them, and make recommendations for future assay development. We found that the KCs are clearly distinct from the Hallmarks of Cancer, that interrelationships among the KCs can be leveraged to strengthen the KC approach (and an understanding of environmental carcinogenesis), and that the KC approach is applicable to the systematic evaluation of a broad range of potential cancer hazards in vivo and in vitro We identified gaps in coverage of the KCs by current assays. Future efforts should expand the breadth, specificity, and sensitivity of validated assays and biomarkers that can measure the 10 KCs. Refinement of the KC approach will enhance and accelerate carcinogen identification, a first step in cancer prevention.See all articles in this CEBP Focus section, "Environmental Carcinogenesis: Pathways to Prevention."
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Affiliation(s)
- Martyn T Smith
- Division of Environmental Health Sciences, School of Public Health, University of California Berkeley, Berkeley, California.
| | - Kathryn Z Guyton
- Monographs Programme, International Agency for Research on Cancer, Lyon, France
| | - Nicole Kleinstreuer
- Division of Intramural Research, Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, North Carolina
- National Toxicology Program Interagency Center for the Evaluation of Alternative Toxicological Methods, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Alexandre Borrel
- Division of Intramural Research, Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, North Carolina
| | - Andres Cardenas
- Division of Environmental Health Sciences, School of Public Health, University of California Berkeley, Berkeley, California
| | - Weihsueh A Chiu
- Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas
| | - Dean W Felsher
- Division of Oncology, Departments of Medicine and Pathology, Stanford University School of Medicine, Stanford, California
| | - Catherine F Gibbons
- Office of Research and Development, US Environmental Protection Agency, Washington, D.C
| | - William H Goodson
- California Pacific Medical Center Research Institute, San Francisco, California
| | - Keith A Houck
- Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, North Carolina
| | - Agnes B Kane
- Department of Pathology and Laboratory Medicine, Alpert Medical School, Brown University, Providence, Rhode Island
| | - Michele A La Merrill
- Department of Environmental Toxicology, University of California, Davis, California
| | - Herve Lebrec
- Comparative Biology & Safety Sciences, Amgen Research, Amgen Inc., Thousand Oaks, California
| | - Leroy Lowe
- Getting to Know Cancer, Truro, Nova Scotia, Canada
| | - Cliona M McHale
- Division of Environmental Health Sciences, School of Public Health, University of California Berkeley, Berkeley, California
| | - Sheroy Minocherhomji
- Comparative Biology & Safety Sciences, Amgen Research, Amgen Inc., Thousand Oaks, California
| | - Linda Rieswijk
- Division of Environmental Health Sciences, School of Public Health, University of California Berkeley, Berkeley, California
- Institute of Data Science, Maastricht University, Maastricht, the Netherlands
| | - Martha S Sandy
- Office of Environmental Health Hazard Assessment, California Environmental Protection Agency, Oakland, California
| | - Hideko Sone
- Yokohama University of Pharmacy and National Institute for Environmental Studies, Tsukuba Ibaraki, Japan
| | - Amy Wang
- Office of the Report on Carcinogens, Division of National Toxicology Program, The National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Luoping Zhang
- Division of Environmental Health Sciences, School of Public Health, University of California Berkeley, Berkeley, California
| | - Lauren Zeise
- Office of Environmental Health Hazard Assessment, California Environmental Protection Agency, Oakland, California
| | - Mark Fielden
- Expansion Therapeutics Inc, San Diego, California
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12
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Hung PH, Savidge M, De M, Kang JC, Healy SM, Valerio LG. In vitro and in silico genetic toxicity screening of flavor compounds and other ingredients in tobacco products with emphasis on ENDS. J Appl Toxicol 2020; 40:1566-1587. [PMID: 32662109 DOI: 10.1002/jat.4020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 05/12/2020] [Accepted: 05/16/2020] [Indexed: 12/16/2022]
Abstract
Electronic nicotine delivery systems (ENDS) are regulated tobacco products and often contain flavor compounds. Given the concern of increased use and the appeal of ENDS by young people, evaluating the potential of flavors to induce DNA damage is important for health hazard identification. In this study, alternative methods were used as prioritization tools to study the genotoxic mode of action (MoA) of 150 flavor compounds. In particular, clastogen-sensitive (γH2AX and p53) and aneugen-sensitive (p-H3 and polyploidy) biomarkers of DNA damage in human TK6 cells were aggregated through a supervised three-pronged ensemble machine learning prediction model to prioritize chemicals based on genotoxicity. In addition, in silico quantitative structure-activity relationship (QSAR) models were used to predict genotoxicity and carcinogenic potential. The in vitro assay identified 25 flavors as positive for genotoxicity: 15 clastogenic, eight aneugenic and two with a mixed MoA (clastogenic and aneugenic). Twenty-three of these 25 flavors predicted to induce DNA damage in vitro are documented in public literature to be in e-liquid or in the aerosols produced by ENDS products with youth-appealing flavors and names. QSAR models predicted 46 (31%) of 150 compounds having at least one positive call for mutagenicity, clastogenicity or rodent carcinogenicity, 49 (33%) compounds were predicted negative for all three endpoints, and remaining compounds had no prediction call. The parallel use of these predictive technologies to elucidate MoAs for potential genetic damage, hold utility as a screening strategy. This study is the first high-content and high-throughput genotoxicity screening study with an emphasis on flavors in ENDS products.
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Affiliation(s)
- Pei-Hsuan Hung
- Division of Nonclinical Science, Office of Science, Center for Tobacco Products, United States Food and Drug Administration, Silver Spring, Maryland, USA
| | - Matthew Savidge
- Division of Nonclinical Science, Office of Science, Center for Tobacco Products, United States Food and Drug Administration, Silver Spring, Maryland, USA
| | - Mamata De
- Division of Nonclinical Science, Office of Science, Center for Tobacco Products, United States Food and Drug Administration, Silver Spring, Maryland, USA
| | - Jueichuan Connie Kang
- Division of Nonclinical Science, Office of Science, Center for Tobacco Products, United States Food and Drug Administration, Silver Spring, Maryland, USA.,US Public Health Service Commissioned Corps, Rockville, MD, USA
| | - Sheila M Healy
- Division of Nonclinical Science, Office of Science, Center for Tobacco Products, United States Food and Drug Administration, Silver Spring, Maryland, USA
| | - Luis G Valerio
- Division of Nonclinical Science, Office of Science, Center for Tobacco Products, United States Food and Drug Administration, Silver Spring, Maryland, USA
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13
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Nguyen AK, Goering PL, Elespuru RK, Sarkar Das S, Narayan RJ. The Photoinitiator Lithium Phenyl (2,4,6-Trimethylbenzoyl) Phosphinate with Exposure to 405 nm Light Is Cytotoxic to Mammalian Cells but Not Mutagenic in Bacterial Reverse Mutation Assays. Polymers (Basel) 2020; 12:E1489. [PMID: 32635323 PMCID: PMC7408440 DOI: 10.3390/polym12071489] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 06/25/2020] [Accepted: 07/01/2020] [Indexed: 02/07/2023] Open
Abstract
Lithium phenyl (2,4,6-trimethylbenzoyl) phosphinate (LAP) is a free radical photo-initiator used to initiate free radical chain polymerization upon light exposure, and is combined with gelatin methacryloyl (GelMA) to produce a photopolymer used in bioprinting. The free radicals produced under bioprinting conditions are potentially cytotoxic and mutagenic. Since these photo-generated free radicals are highly-reactive but short-lived, toxicity assessments should be conducted with light exposure. In this study, photorheology determined that 10 min exposure to 9.6 mW/cm2 405 nm light from an LED light source fully crosslinked 10 wt % GelMA with >3.4 mmol/L LAP, conditions that were used for subsequent cytotoxicity and mutagenicity assessments. These conditions were cytotoxic to M-1 mouse kidney collecting duct cells, a cell type susceptible to lithium toxicity. Exposure to ≤17 mmol/L (0.5 wt %) LAP without light was not cytotoxic; however, concurrent exposure to ≥3.4 mmol/L LAP and light was cytotoxic. No condition of LAP and/or light exposure evaluated was mutagenic in bacterial reverse mutation assays using S. typhimurium strains TA98, TA100 and E. coli WP2 uvrA. These data indicate that the combination of LAP and free radicals generated from photo-excited LAP is cytotoxic, but mutagenicity was not observed in bacteria under typical bioprinting conditions.
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Affiliation(s)
- Alexander K. Nguyen
- Joint UNC/NCSU Department of Biomedical Engineering, North Carolina State University, Raleigh, NC 27695, USA;
- Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA; (P.L.G.); (R.K.E.); (S.S.D.)
| | - Peter L. Goering
- Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA; (P.L.G.); (R.K.E.); (S.S.D.)
| | - Rosalie K. Elespuru
- Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA; (P.L.G.); (R.K.E.); (S.S.D.)
| | - Srilekha Sarkar Das
- Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA; (P.L.G.); (R.K.E.); (S.S.D.)
| | - Roger J. Narayan
- Joint UNC/NCSU Department of Biomedical Engineering, North Carolina State University, Raleigh, NC 27695, USA;
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Risjani Y, Loppion G, Couteau J, Yunianta Y, Widowati I, Hermawati A, Minier C. Genotoxicity in the rivers from the Brantas catchment (East Java, Indonesia): occurrence in sediments and effects in Oreochromis niloticus (Linnæus 1758). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:21905-21913. [PMID: 32285390 DOI: 10.1007/s11356-020-08575-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 03/23/2020] [Indexed: 06/11/2023]
Abstract
This paper reports the first data from an integrated study investigating genotoxicity in the Brantas River, Java, Indonesia. Results showed that organic sediment extracts from the sites in the Brantas Delta retained genotoxic compounds identified using the SOS Chromotest and that the Aloo River and, to a lesser extent, the Surabaya River were the most contaminated studied sites. This genotoxicity was attributable to compounds that did not require any bioactivation under the test conditions. Occurrence of genotoxic effects was further investigated in erythrocytes from Nile tilapia, Oreochromis niloticus. High numbers of micronuclei were counted, especially in fish sampled in the rivers of the Brantas Delta. Moreover, cytoplasmic alterations which could be indicative of the presence of lipofuscin were found in the cytoplasm of the fish blood cells, especially in fish from the Aloo, Surabaya and Kalimas rivers. Altogether, our data showed that genotoxicity is occurring in fish living in rivers of the delta of the Brantas River and suggest that sediments from these sites may constitute a major source of pollution and hazard for species living or feeding in the area.
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Affiliation(s)
- Yenny Risjani
- Faculty of Fisheries and Marine Sciences, Universitas Brawijaya, Malang, Indonesia
- BioEcotox Research Center, Universitas Brawijaya, Malang, Indonesia
| | | | | | - Yunianta Yunianta
- BioEcotox Research Center, Universitas Brawijaya, Malang, Indonesia
- Faculty of Agricultural Technology, Universitas Brawijaya, Malang, Indonesia
| | - Ita Widowati
- Faculty of Fisheries and Marine Sciences, Universitas Diponegoro, Semarang, Indonesia
| | - Alfi Hermawati
- Faculty of Fisheries and Marine Sciences, Universitas Udayana, Denpasar, Indonesia
| | - Christophe Minier
- UMR-I 02 SEBIO, University of Le Havre-Normandie, 30 rue Philippe Lebon, Le Havre, France.
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15
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David R. The promise of toxicogenomics for genetic toxicology: past, present and future. Mutagenesis 2020; 35:153-159. [PMID: 32087008 DOI: 10.1093/mutage/geaa007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 02/10/2020] [Indexed: 01/10/2023] Open
Abstract
Toxicogenomics, the application of genomics to toxicology, was described as 'a new era' for toxicology. Standard toxicity tests typically involve a number of short-term bioassays that are costly, time consuming, require large numbers of animals and generally focus on a single end point. Toxicogenomics was heralded as a way to improve the efficiency of toxicity testing by assessing gene regulation across the genome, allowing rapid classification of compounds based on characteristic expression profiles. Gene expression microarrays could measure and characterise genome-wide gene expression changes in a single study and while transcriptomic profiles that can discriminate between genotoxic and non-genotoxic carcinogens have been identified, challenges with the approach limited its application. As such, toxicogenomics did not transform the field of genetic toxicology in the way it was predicted. More recently, next generation sequencing (NGS) technologies have revolutionised genomics owing to the fact that hundreds of billions of base pairs can be sequenced simultaneously cheaper and quicker than traditional Sanger methods. In relation to genetic toxicology, and thousands of cancer genomes have been sequenced with single-base substitution mutational signatures identified, and mutation signatures have been identified following treatment of cells with known or suspected environmental carcinogens. RNAseq has been applied to detect transcriptional changes following treatment with genotoxins; modified RNAseq protocols have been developed to identify adducts in the genome and Duplex sequencing is an example of a technique that has recently been developed to accurately detect mutation. Machine learning, including MutationSeq and SomaticSeq, has also been applied to somatic mutation detection and improvements in automation and/or the application of machine learning algorithms may allow high-throughput mutation sequencing in the future. This review will discuss the initial promise of transcriptomics for genetic toxicology, and how the development of NGS technologies and new machine learning algorithms may finally realise that promise.
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Affiliation(s)
- Rhiannon David
- Clinical Pharmacology and Safety Sciences, R&D, AstraZeneca, Cambridge, UK
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16
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Genotoxic and Anatomical Deteriorations Associated with Potentially Toxic Elements Accumulation in Water Hyacinth Grown in Drainage Water Resources. SUSTAINABILITY 2020. [DOI: 10.3390/su12052147] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Potentially toxic elements (PTEs)-induced genotoxicity on aquatic plants is still an open question. Herein, a single clone from a population of water hyacinth covering a large distribution area of Nile River (freshwater) was transplanted in two drainage water resources to explore the hazardous effect of PTEs on molecular, biochemical and anatomical characters of plants compared to those grown in freshwater. Inductivity Coupled Plasma (ICP) analysis indicated that PTEs concentrations in water resources were relatively low in most cases. However, the high tendency of water hyacinth to bio-accumulate and bio-magnify PTEs maximized their concentrations in plant samples (roots in particular). A Random Amplified Polymorphic DNA (RAPD) assay showed the genotoxic effects of PTEs on plants grown in drainage water. PTEs accumulation caused substantial alterations in DNA profiles including the presence or absence of certain bands and even the appearance of new bands. Plants grown in drainage water exhibited several mutations on the electrophoretic profiles and banding pattern of total protein, especially proteins isolated from roots. Several anatomical deteriorations were observed on PTEs-stressed plants including reductions in the thickness of epidermis, cortex and endodermis as well as vascular cylinder diameter. The research findings of this investigation may provide some new insights regarding molecular, biochemical and anatomical responses of water hyacinth grown in drainage water resources.
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17
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Standardization of antimicrobial testing of dental devices. Dent Mater 2020; 36:e59-e73. [DOI: 10.1016/j.dental.2019.12.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Accepted: 12/15/2019] [Indexed: 11/23/2022]
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18
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Sun D, Zhao T, Wang T, Wu M, Zhang Z. Genotoxicity assessment of triclocarban by comet and micronucleus assays and Ames test. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:7430-7438. [PMID: 31884548 DOI: 10.1007/s11356-019-07351-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 12/09/2019] [Indexed: 06/10/2023]
Abstract
The widespread usage and ubiquitous distribution of triclocarban (3,4,4'-trichlorocarbanilide, TCC) have raised public concerns about its health effects. At present, there is little information about the genotoxicity of TCC. In this study, we used a battery of genotoxicity testing methods including salmonella reverse mutation test (Ames test), comet assay and micronucleus assay to detect the effects of TCC on gene mutation, DNA breakage, and chromosome damage. The results of Ames test showed that TCC at 0.1-1000 μg/plate did not significantly increase the number of revertant colonies in the four standard Salmonella typhimurium strains, i.e., TA97, TA98, TA100, and TA102, when compared to the vehicle control. The results from comet assay demonstrated that exposure to 5, 10, or 15 μM TCC for 24 h did not significantly increase the percentage of comet cells, tail length (TL), DNA in tail (T DNA%), or olive tail moment (OTM) in keratinocyte HaCaT and hepatic L02 cells. Moreover, TCC did not markedly enhance the frequency of micronucleated cells or micronuclei in HaCaT and L02 cells in the micronucleus assay. Taken together, the results indicated that TCC did not exhibit any genotoxic effects. Our study provides additional information for the safety profile of TCC.
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Affiliation(s)
- Donglei Sun
- Department of Environmental and Occupational Health, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Tianhe Zhao
- Department of Environmental and Occupational Health, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Ting Wang
- Department of Environmental and Occupational Health, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Mei Wu
- Department of Environmental and Occupational Health, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Zunzhen Zhang
- Department of Environmental and Occupational Health, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, 610041, Sichuan, China.
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19
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Kim DV, Makarova AV, Miftakhova RR, Zharkov DO. Base Excision DNA Repair Deficient Cells: From Disease Models to Genotoxicity Sensors. Curr Pharm Des 2020; 25:298-312. [PMID: 31198112 DOI: 10.2174/1381612825666190319112930] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 03/13/2019] [Indexed: 12/29/2022]
Abstract
Base excision DNA repair (BER) is a vitally important pathway that protects the cell genome from many kinds of DNA damage, including oxidation, deamination, and hydrolysis. It involves several tightly coordinated steps, starting from damaged base excision and followed by nicking one DNA strand, incorporating an undamaged nucleotide, and DNA ligation. Deficiencies in BER are often embryonic lethal or cause morbid diseases such as cancer, neurodegeneration, or severe immune pathologies. Starting from the early 1980s, when the first mammalian cell lines lacking BER were produced by spontaneous mutagenesis, such lines have become a treasure trove of valuable information about the mechanisms of BER, often revealing unexpected connections with other cellular processes, such as antibody maturation or epigenetic demethylation. In addition, these cell lines have found an increasing use in genotoxicity testing, where they provide increased sensitivity and representativity to cell-based assay panels. In this review, we outline current knowledge about BER-deficient cell lines and their use.
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Affiliation(s)
- Daria V Kim
- Novosibirsk State University, 2 Pirogova St., Novosibirsk 630090, Russian Federation
| | - Alena V Makarova
- RAS Institute of Molecular Genetics, 2 Kurchatova Sq., Moscow 123182, Russian Federation
| | - Regina R Miftakhova
- Kazan Federal University, 18 Kremlevsakaya St., Kazan 420008, Russian Federation
| | - Dmitry O Zharkov
- Novosibirsk State University, 2 Pirogova St., Novosibirsk 630090, Russian Federation.,SB RAS Institute of Chemical Biology and Fu ndamental Medicine, 8 Lavrentieva Ave., Novosibirsk 630090, Russian Federation
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20
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Chen R, Zhou C, Cao Y, Xi J, Ohira T, He L, Huang P, You X, Liu W, Zhang X, Ma S, Xie T, Chang Y, Luan Y. Assessment of Pig-a, Micronucleus, and Comet Assay Endpoints in Tg.RasH2 Mice Carcinogenicity Study of Aristolochic Acid I. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:266-275. [PMID: 31443125 DOI: 10.1002/em.22325] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 08/16/2019] [Accepted: 08/19/2019] [Indexed: 06/10/2023]
Abstract
A newly developed in vivo Pig-a gene mutation assay displays great potential for integration into genotoxicity tests. To obtain more evidence for application of the Pig-a assay, we integrated this assay, micronucleus test in peripheral blood (MN-pb test) and bone marrow (MN-bm test), as well as a Comet assay into a transgenic RasH2 mice carcinogenicity study. Fourteen male RasH2 mice and five wild-type (WT) mice were treated with a strong mutagen aristolochic acid I at a dose of 5 mg/kg/day for 4 consecutive weeks. Mice recovered in 5 weeks. Peripheral bloods were collected for Pig-a assay, MN-pb test, and Comet assay at several time points, while bone marrow and target organs were harvested for the MN-bm test and pathological diagnosis after mice were euthanized. Finally, 13 of the 14 RasH2 mice developed squamous cell carcinomas in the forestomach, while there were no carcinomas in the WT mice. Pig-a mutant frequencies (MFs) consecutively increased throughout the study to a maximum value of approximately 63-fold more than background. These frequencies were relative to the incidence, size, and malignant degree of tumors. Micronucleated reticulocytes increased from Day 1 to Day 49, before returning to background levels. No positive responses were observed in either the MN-bm test or the Comet assay. Results suggested that, when compared with the other two tests, the Pig-a assay persistently contributed to sustaining MFs, enhanced detection sensitivity due to the accumulation of Pig-a mutations, and demonstrated better predictability for tumorigenicity. Environ. Mol. Mutagen. 61:266-275, 2020. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Ruixue Chen
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Changhui Zhou
- Shanghai InnoStar Bio-Tech Co., Ltd., National Shanghai Center for New Drug Safety Evaluation and Research, Shanghai, People's Republic of China
| | - Yiyi Cao
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
- Joint Laboratory on Herbal Safety, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Jing Xi
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
- Joint Laboratory on Herbal Safety, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Toko Ohira
- Shanghai InnoStar Bio-Tech Co., Ltd., National Shanghai Center for New Drug Safety Evaluation and Research, Shanghai, People's Republic of China
| | - Liang He
- Shanghai InnoStar Bio-Tech Co., Ltd., National Shanghai Center for New Drug Safety Evaluation and Research, Shanghai, People's Republic of China
| | - Pengcheng Huang
- Shanghai InnoStar Bio-Tech Co., Ltd., National Shanghai Center for New Drug Safety Evaluation and Research, Shanghai, People's Republic of China
| | - Xinyue You
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Weiying Liu
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Xinyu Zhang
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
- Joint Laboratory on Herbal Safety, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Shuangcheng Ma
- Joint Laboratory on Herbal Safety, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
- National Institutes for Food and Drug Control, Beijing, China
| | - Tianpei Xie
- Joint Laboratory on Herbal Safety, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
- Shanghai Standard Technology Co., Ltd., Shanghai, People's Republic of China
| | - Yan Chang
- Shanghai InnoStar Bio-Tech Co., Ltd., National Shanghai Center for New Drug Safety Evaluation and Research, Shanghai, People's Republic of China
| | - Yang Luan
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
- Joint Laboratory on Herbal Safety, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
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21
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Luijten M, Ball NS, Dearfield KL, Gollapudi BB, Johnson GE, Madia F, Peel L, Pfuhler S, Settivari RS, ter Burg W, White PA, van Benthem J. Utility of a next generation framework for assessment of genomic damage: A case study using the industrial chemical benzene. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:94-113. [PMID: 31709603 PMCID: PMC6972600 DOI: 10.1002/em.22346] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 10/31/2019] [Accepted: 11/06/2019] [Indexed: 05/22/2023]
Abstract
We recently published a next generation framework for assessing the risk of genomic damage via exposure to chemical substances. The framework entails a systematic approach with the aim to quantify risk levels for substances that induce genomic damage contributing to human adverse health outcomes. Here, we evaluated the utility of the framework for assessing the risk for industrial chemicals, using the case of benzene. Benzene is a well-studied substance that is generally considered a genotoxic carcinogen and is known to cause leukemia. The case study limits its focus on occupational and general population health as it relates to benzene exposure. Using the framework as guidance, available data on benzene considered relevant for assessment of genetic damage were collected. Based on these data, we were able to conduct quantitative analyses for relevant data sets to estimate acceptable exposure levels and to characterize the risk of genetic damage. Key observations include the need for robust exposure assessments, the importance of information on toxicokinetic properties, and the benefits of cheminformatics. The framework points to the need for further improvement on understanding of the mechanism(s) of action involved, which would also provide support for the use of targeted tests rather than a prescribed set of assays. Overall, this case study demonstrates the utility of the next generation framework to quantitatively model human risk on the basis of genetic damage, thereby enabling a new, innovative risk assessment concept. Environ. Mol. Mutagen. 61:94-113, 2020. © 2019 The Authors. Environmental and Molecular Mutagenesis published by Wiley Periodicals, Inc. on behalf of Environmental Mutagen Society.
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Affiliation(s)
- Mirjam Luijten
- Centre for Health ProtectionNational Institute for Public Health and the Environment (RIVM)BilthovenThe Netherlands
| | | | | | | | - George E. Johnson
- Swansea University Medical School, Swansea UniversitySwanseaUnited Kingdom
| | - Federica Madia
- European Commission, Joint Research Centre (JRC)IspraItaly
| | - Lauren Peel
- Health and Environmental Sciences InstituteWashingtonDistrict of Columbia
| | | | | | - Wouter ter Burg
- Centre for Safety of Substances and ProductsNational Institute for Public Health and the Environment (RIVM)BilthovenThe Netherlands
| | - Paul A. White
- Department of BiologyUniversity of OttawaOttawaOntarioCanada
| | - Jan van Benthem
- Centre for Health ProtectionNational Institute for Public Health and the Environment (RIVM)BilthovenThe Netherlands
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22
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Sasaki JC, Allemang A, Bryce SM, Custer L, Dearfield KL, Dietz Y, Elhajouji A, Escobar PA, Fornace AJ, Froetschl R, Galloway S, Hemmann U, Hendriks G, Li HH, Luijten M, Ouedraogo G, Peel L, Pfuhler S, Roberts DJ, Thybaud V, van Benthem J, Yauk CL, Schuler M. Application of the adverse outcome pathway framework to genotoxic modes of action. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:114-134. [PMID: 31603995 DOI: 10.1002/em.22339] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/17/2019] [Accepted: 09/23/2019] [Indexed: 05/22/2023]
Abstract
In May 2017, the Health and Environmental Sciences Institute's Genetic Toxicology Technical Committee hosted a workshop to discuss whether mode of action (MOA) investigation is enhanced through the application of the adverse outcome pathway (AOP) framework. As AOPs are a relatively new approach in genetic toxicology, this report describes how AOPs could be harnessed to advance MOA analysis of genotoxicity pathways using five example case studies. Each of these genetic toxicology AOPs proposed for further development includes the relevant molecular initiating events, key events, and adverse outcomes (AOs), identification and/or further development of the appropriate assays to link an agent to these events, and discussion regarding the biological plausibility of the proposed AOP. A key difference between these proposed genetic toxicology AOPs versus traditional AOPs is that the AO is a genetic toxicology endpoint of potential significance in risk characterization, in contrast to an adverse state of an organism or a population. The first two detailed case studies describe provisional AOPs for aurora kinase inhibition and tubulin binding, leading to the common AO of aneuploidy. The remaining three case studies highlight provisional AOPs that lead to chromosome breakage or mutation via indirect DNA interaction (inhibition of topoisomerase II, production of cellular reactive oxygen species, and inhibition of DNA synthesis). These case studies serve as starting points for genotoxicity AOPs that could ultimately be published and utilized by the broader toxicology community and illustrate the practical considerations and evidence required to formalize such AOPs so that they may be applied to genetic toxicity evaluation schemes. Environ. Mol. Mutagen. 61:114-134, 2020. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
| | | | | | - Laura Custer
- Bristol-Myers Squibb Company, Drug Safety Evaluation, New Brunswick, New Jersey
| | | | - Yasmin Dietz
- Sanofi-Aventis Deutschland GmbH, Frankfurt, Germany
| | | | | | | | | | | | | | | | - Heng-Hong Li
- Georgetown University, Washington, District of Columbia
| | - Mirjam Luijten
- National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | | | - Lauren Peel
- Health and Environmental Sciences Institute, Washington, District of Columbia
| | | | | | - Véronique Thybaud
- Sanofi, Research and Development, Preclinical Safety, Vitry-sur-Seine, France
| | - Jan van Benthem
- National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - Carole L Yauk
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Maik Schuler
- Pfizer Inc, World Wide Research and Development, Groton, Connecticut
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23
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Marchetti F, Douglas GR, Yauk CL. A Return to the Origin of the EMGS: Rejuvenating the Quest for Human Germ Cell Mutagens and Determining the Risk to Future Generations. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:42-54. [PMID: 31472026 DOI: 10.1002/em.22327] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 08/21/2019] [Accepted: 08/28/2019] [Indexed: 05/23/2023]
Abstract
Fifty years ago, the Environmental Mutagen Society (now Environmental Mutagenesis and Genomics Society) was founded with a laser-focus on germ cell mutagenesis and the protection of "our most vital assets"-the sperm and egg genomes. Yet, five decades on, despite the fact that many agents have been demonstrated to induce inherited changes in the offspring of exposed laboratory rodents, there is no consensus on whether human germ cell mutagens exist. We argue that it is time to reevaluate the available data and conclude that we already have evidence for the existence of environmental exposures that impact human germ cells. What is missing are definite data to demonstrate a significant increase in de novo mutations in the offspring of exposed parents. We believe that with over two decades of research advancing knowledge and technologies in genomics, we are at the cusp of generating data to conclusively show that environmental exposures cause heritable de novo changes in the human offspring. We call on the research community to harness our technologies, synergize our efforts, and return to our Founders' original focus. The next 50 years must involve collaborative work between clinicians, epidemiologists, genetic toxicologists, genomics experts and bioinformaticians to precisely define how environmental exposures impact germ cell genomes. It is time for the research and regulatory communities to prepare to interpret the coming outpouring of data and develop a framework for managing, communicating and mitigating the risk of exposure to human germ cell mutagens. Environ. Mol. Mutagen. 61:42-54, 2020. © 2019 Her Majesty the Queen in Right of Canada.
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Affiliation(s)
- Francesco Marchetti
- Environmental Health Science Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - George R Douglas
- Environmental Health Science Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Carole L Yauk
- Environmental Health Science Research Bureau, Health Canada, Ottawa, Ontario, Canada
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Dobrovolsky VN, Cao X, Bhalli JA, Heflich RH. Detection of Pig-a Mutant Erythrocytes in the Peripheral Blood of Rats and Mice. Methods Mol Biol 2020; 2102:315-331. [PMID: 31989564 DOI: 10.1007/978-1-0716-0223-2_18] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The endogenous X-linked phosphatidyl inositol glycan class A gene (Pig-a) can be used as a reporter of in vivo somatic cell mutation in rats and mice. Pig-a mutant cells are deficient in specific protein surface markers and can be identified and quantified by immunofluorescent staining followed by high-throughput flow cytometry. Pig-a mutation detection is commonly performed with red blood cells (RBCs) because: (1) the low volumes of blood required for determining mutant frequencies in RBCs allow multiple samplings on small laboratory animals over extended periods of time; (2) the execution of the RBC assay is easy and the interpretation of the results is straightforward; and (3) RBC Pig-a mutant frequencies are known within hours of sample collection. Two endpoints are determined in the assay: the frequency of mutant total RBCs and the frequency of mutant reticulocytes. When Pig-a mutation is used to assess the in vivo mutagenic potential of suspect hazards, the frequency of mutant reticulocytes is an early indicator of mutagenic potential, while the mutant frequency in total RBCs can be measured more rapidly and with greater precision.
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Affiliation(s)
- Vasily N Dobrovolsky
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, Jefferson, AR, USA.
| | - Xuefei Cao
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, Jefferson, AR, USA
| | - Javed A Bhalli
- Toxicology/Safety Assessment, Covance Laboratories Inc., Greenfield, IN, USA
| | - Robert H Heflich
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, Jefferson, AR, USA
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25
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Oxidative Stress Induced DNA Damage and Reproductive Toxicity in Male Albino Mice Orally Exposed to Sorbitol. ACTA ACUST UNITED AC 2019. [DOI: 10.2478/ast-2019-0010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Abstract
In this study, the potential DNA damage and reproductive toxicity of sorbitol was investigated using bone marrow micronucleus (MN), sperm morphology, and sperm count in mice. Five doses of 90, 45, 20, 10 and 1 mg/kg/day, defined by allometry, and approximately corresponding to 1.5g, 750mg, 330mg, 165mg and 16mg of sorbitol daily consumption by a 70kg human, respectively, were used. MN analysis showed a dose-dependent induction of micronucleated polychromatic erythrocytes and other nuclear abnormalities across the treatment groups. Assessment of sperm shape showed a significant (p < 0.05) increase in sperm abnormalities with significant (p < 0.05) decrease in mean sperm count in treated groups. The result of the oxidative stress biomarkers showed induction of significant (p < 0.05) increase in liver catalase, MDA and serum ALT and AST activities with concomitant decrease in SOD activities in exposed mice. A significant increase in weight of exposed mice were recorded when compared with the negative control. The results of this study showed the genotoxicity and reproductive effects of sorbitol.
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Abstract
Next generation sequencing (NGS) represents several powerful platforms that have revolutionized RNA and DNA analysis. The parallel sequencing of millions of DNA molecules can provide mechanistic insights into toxicology and provide new avenues for biomarker discovery with growing relevance for risk assessment. The evolution of NGS technologies has improved over the last decade with increased sensitivity and accuracy to foster new biomarker assays from tissue, blood and other biofluids. NGS sequencing technologies can identify transcriptional changes and genomic targets with base pair precision in response to chemical exposure. Further, there are several exciting movements within the toxicology community that incorporate NGS platforms into new strategies for more rapid toxicological characterizations. These include the Tox21 in vitro high throughput transcriptomic screening program, development of organotypic spheroids, alternative animal models, mining archival tissues, liquid biopsy and epigenomics. This review will describe NGS-based technologies, demonstrate how they can be used as tools for target discovery in tissue and blood, and suggest how they might be applied for risk assessment.
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Affiliation(s)
- B Alex Merrick
- Molecular and Genomic Toxicology Group, Biomolecular Screening Branch, Division National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, Ph: 919-541-1531,
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Williams RV, DeMarini DM, Stankowski LF, Escobar PA, Zeiger E, Howe J, Elespuru R, Cross KP. Are all bacterial strains required by OECD mutagenicity test guideline TG471 needed? MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2019; 848:503081. [DOI: 10.1016/j.mrgentox.2019.503081] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 06/19/2019] [Accepted: 08/08/2019] [Indexed: 11/24/2022]
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28
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Dertinger SD, Totsuka Y, Bielas JH, Doherty AT, Kleinjans J, Honma M, Marchetti F, Schuler MJ, Thybaud V, White P, Yauk CL. High information content assays for genetic toxicology testing: A report of the International Workshops on Genotoxicity Testing (IWGT). MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2019; 847:403022. [DOI: 10.1016/j.mrgentox.2019.02.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 01/30/2019] [Accepted: 02/20/2019] [Indexed: 12/21/2022]
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White PA, Luijten M, Mishima M, Cox JA, Hanna JN, Maertens RM, Zwart EP. In vitro mammalian cell mutation assays based on transgenic reporters: A report of the International Workshop on Genotoxicity Testing (IWGT). MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2019; 847:403039. [DOI: 10.1016/j.mrgentox.2019.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 03/26/2019] [Accepted: 04/06/2019] [Indexed: 02/07/2023]
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Takeshita T, Kanaly RA. In vitro DNA/RNA Adductomics to Confirm DNA Damage Caused by Benzo[ a]pyrene in the Hep G2 Cell Line. Front Chem 2019; 7:491. [PMID: 31338364 PMCID: PMC6629907 DOI: 10.3389/fchem.2019.00491] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 06/25/2019] [Indexed: 11/13/2022] Open
Abstract
In the development of new chemical substances, genetic toxicity evaluations are a high priority for safety risk management. Evaluation of the possibility of compound carcinogenicity with accuracy and at reasonable cost in the early stages of development by in vitro techniques is preferred. Currently, DNA damage-related in vitro genotoxicity tests are widely-used screening tools after which next generation toxicity testing may be applied to confirm DNA damage. DNA adductomics may be used to evaluate DNA damage in vitro, however confirmation of DNA adduct identities through comparison to authentic standards may be time-consuming and expensive processes. Considering this, a streamlined method for confirming putative DNA adducts that are detected by DNA adductomics may be useful. With this aim, in vitro DNA adductome methods in conjunction with in vitro RNA adductome methods may be proposed as a DNA adductome verification approach by which to eliminate false positive annotations. Such an approach was evaluated by conducting in vitro assays whereby Hep G2 cell lines that were exposed to or not exposed to benzo[a]pyrene were digested to their respective 2'-deoxynucleosides or ribonucleosides and analyzed by liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) by comparative DNA and RNA adductomics through neutral loss targeting of the [M + H]+ > [M + H - 116]+ or [M + H]+ > [M + H -132]+ transitions over predetermined ranges. Comparisons of DNA adductome maps revealed putative DNA adducts that were detected in exposed cells but not in unexposed cells. Similarly, comparisons of RNA adductome maps revealed putative RNA adducts in exposed cells but not in unexposed cells. Taken together these experiments revealed that analogous forms of putative damage had occurred in both DNA and RNA which supported that putative DNA adducts detected by DNA adductomics were DNA adducts. High resolution mass spectrometry (HRMS) was utilized to confirm that putative nucleic acid adducts detected in both DNA and RNA were derived from benzo[a]pyrene exposure and these putative adducts were identified as 7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene- (B[a]PDE)-type adducts. Overall, this study demonstrates the usefulness of utilizing DNA/RNA adductomics to screen for nucleic acid damage.
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Affiliation(s)
| | - Robert A. Kanaly
- Department of Life and Environmental System Science, Graduate School of Nanobiosciences, Yokohama City University, Yokohama, Japan
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31
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Pacchierotti F, Masumura K, Eastmond DA, Elhajouji A, Froetschl R, Kirsch-Volders M, Lynch A, Schuler M, Tweats D, Marchetti F. Chemically induced aneuploidy in germ cells. Part II of the report of the 2017 IWGT workgroup on assessing the risk of aneugens for carcinogenesis and hereditary diseases. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2019; 848:403023. [PMID: 31708072 DOI: 10.1016/j.mrgentox.2019.02.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 02/01/2019] [Accepted: 02/20/2019] [Indexed: 12/18/2022]
Abstract
As part of the 7th International Workshops on Genotoxicity Testing held in Tokyo, Japan in November 2017, a workgroup of experts reviewed and assessed the risk of aneugens for human health. The present manuscript is one of three manuscripts from the workgroup and reports on the unanimous consensus reached on the evidence for aneugens affecting germ cells, their mechanisms of action and role in hereditary diseases. There are 24 chemicals with strong or sufficient evidence for germ cell aneugenicity providing robust support for the ability of chemicals to induce germ cell aneuploidy. Interference with microtubule dynamics or inhibition of topoisomerase II function are clear characteristics of germ cell aneugens. Although there are mechanisms of chromosome segregation that are unique to germ cells, there is currently no evidence for germ cell-specific aneugens. However, the available data are heavily skewed toward chemicals that are aneugenic in somatic cells. Development of high-throughput screening assays in suitable animal models for exploring additional targets for aneuploidy induction, such as meiosis-specific proteins, and to prioritize chemicals for the potential to be germ cell aneugens is encouraged. Evidence in animal models support that: oocytes are more sensitive than spermatocytes and somatic cells to aneugens; exposure to aneugens leads to aneuploid conceptuses; and, the frequencies of aneuploidy are similar in germ cells and zygotes. Although aneuploidy in germ cells is a significant cause of infertility and pregnancy loss in humans, there is currently limited evidence that aneugens induce hereditary diseases in human populations because the great majority of aneuploid conceptuses die in utero. Overall, the present work underscores the importance of protecting the human population from exposure to chemicals that can induce aneuploidy in germ cells that, in contrast to carcinogenicity, is directly linked to an adverse outcome.
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Affiliation(s)
- Francesca Pacchierotti
- Health Protection Technology Division, Laboratory of Biosafety and Risk Assessment, ENEA, CR Casaccia, Rome, Italy
| | - Kenichi Masumura
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, Kanagawa, Japan
| | - David A Eastmond
- Department of Molecular, Cell and System Biology, University of California, Riverside, CA, USA
| | - Azeddine Elhajouji
- Novartis Institutes for Biomedical Research, Preclinical Safety, Basel, Switzerland
| | | | - Micheline Kirsch-Volders
- Laboratory for Cell Genetics, Faculty of Sciences and Bio-Engineering, Vrije Universiteit Brussel, Brussels, Belgium
| | | | | | | | - Francesco Marchetti
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON K1A 0K9, Canada.
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32
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Davoren MJ, Schiestl RH. Glyphosate-based herbicides and cancer risk: a post-IARC decision review of potential mechanisms, policy and avenues of research. Carcinogenesis 2018; 39:1207-1215. [PMID: 30060078 PMCID: PMC7530464 DOI: 10.1093/carcin/bgy105] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 07/04/2018] [Accepted: 07/27/2018] [Indexed: 12/13/2022] Open
Abstract
Since its initial sales in the 1970s, the herbicide glyphosate attained widespread use in modern agriculture, becoming the most commercially successful and widely used herbicide of all time as of 2016. Despite a primary mechanism that targets a pathway absent from animal cells and regulatory studies showing safety margins orders of magnitude better than many other, more directly toxic herbicides, the safety status of glyphosate has recently been brought into question by a slow accumulation of studies suggesting more subtle health risks, especially when considered in combination with the surfactants it is usually applied with. Current, official views of respected international regulatory and health bodies remain divided on glyphosate's status as a human carcinogen, but the 2015 International Agency for Research on Cancer decision to reclassify the compound as Category 2A (probably carcinogenic to humans) marked a sea change in the scientific community's consensus view. The goal of this review is to consider the state of science regarding glyphosate's potential as a human carcinogen and genotoxin, with particular focus on studies suggesting mechanisms that would go largely undetected in traditional toxicology studies, such as microbiome disruption and endocrine mimicry at very low concentrations.
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Affiliation(s)
- Michael J Davoren
- Molecular Toxicology Interdepartmental Program, University of California, Los Angeles, CA, USA
| | - Robert H Schiestl
- Molecular Toxicology Interdepartmental Program, University of California, Los Angeles, CA, USA
- Pathology and Laboratory Medicine, University of California, Los Angeles, CA, USA
- Environmental Health Science, University of California, Los Angeles, CA, USA
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33
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Bryce SM, Bernacki DT, Smith-Roe SL, Witt KL, Bemis JC, Dertinger SD. Investigating the Generalizability of the MultiFlow ® DNA Damage Assay and Several Companion Machine Learning Models With a Set of 103 Diverse Test Chemicals. Toxicol Sci 2018; 162:146-166. [PMID: 29106658 PMCID: PMC6059150 DOI: 10.1093/toxsci/kfx235] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The in vitro MultiFlow DNA Damage assay multiplexes p53, γH2AX, phospho-histone H3, and polyploidization biomarkers into 1 flow cytometric analysis (Bryce, S. M., Bernacki, D. T., Bemis, J. C., and Dertinger, S. D. (2016). Genotoxic mode of action predictions from a multiplexed flow cytometric assay and a machine learning approach. Environ. Mol. Mutagen. 57, 171-189). The work reported herein evaluated the generalizability of the method, as well as several data analytics strategies, to a range of chemical classes not studied previously. TK6 cells were exposed to each of 103 diverse chemicals, 86 of which were supplied by the National Toxicology Program (NTP) and selected based upon responses in genetic damage assays conducted under the Tox21 program. Exposures occurred for 24 h over a range of concentrations, and cell aliquots were removed at 4 and 24 h for analysis. Multiplexed response data were evaluated using 3 machine learning models designed to predict genotoxic mode of action based on data from a training set of 85 previously studied chemicals. Of 54 chemicals with sufficient information to make an a priori call on genotoxic potential, the prediction models' accuracies were 79.6% (random forest), 88.9% (logistic regression), and 90.7% (artificial neural network). A majority vote ensemble of the 3 models provided 92.6% accuracy. Forty-nine NTP chemicals were not adequately tested (maximum concentration did not approach assay's cytotoxicity limit) and/or had insufficient conventional genotoxicity data to allow their genotoxic potential to be defined. For these chemicals MultiFlow data will be useful in future research and hypothesis testing. Collectively, the results suggest the MultiFlow assay and associated data analysis strategies are broadly generalizable, demonstrating high predictability when applied to new chemicals and classes of compounds.
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Affiliation(s)
| | | | - Stephanie L Smith-Roe
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Kristine L Witt
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
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34
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Sarac N, Baygar T, Ugur A. In vitro
mutagenic and anti‐mutagenic properties of green synthesised silver nanoparticles. IET Nanobiotechnol 2017. [DOI: 10.1049/iet-nbt.2017.0016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Nurdan Sarac
- Department of BiologyFaculty of ScienceMugla Sitki Kocman UniversityMuglaTurkey
| | - Tuba Baygar
- Material Research LaboratoryResearch Laboratories CenterMugla Sitki Kocman UniversityMuglaTurkey
| | - Aysel Ugur
- Section of Medical MicrobiologyDepartment of Basic SciencesFaculty of DentistryGazi UniversityAnkaraTurkey
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35
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Booth ED, Rawlinson PJ, Maria Fagundes P, Leiner KA. Regulatory requirements for genotoxicity assessment of plant protection product active ingredients, impurities, and metabolites. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2017; 58:325-344. [PMID: 28329407 DOI: 10.1002/em.22084] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 02/28/2017] [Indexed: 06/06/2023]
Abstract
Active ingredients in plant protection products are subject to rigorous safety assessment during their development, including assessment of genotoxicity. Plant protection products are used for agriculture in multiple regions and for the registration of active ingredients it is necessary to satisfy the data requirements of these different regions. There are no overarching global agreements on which genotoxicity studies need to be conducted to satisfy the majority of regulatory authorities. The implementation of new OECD guidelines for the in vitro micronucleus, transgenic rodent somatic and germ cell gene mutation and in vivo comet assays, as well as the revision of a number of other OECD test guidelines has resulted in some changes to data requirements. This review describes the genotoxicity data requirements for chemical active ingredients as well as biologicals, microbials, ground water metabolites, metabolites, and impurities in a number of regions. Similarities and differences are highlighted. Environ. Mol. Mutagen. 58:325-344, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Ewan D Booth
- Department of Toxicology and Health Sciences, Syngenta Ltd, Jealott's Hill International Research Centre, Bracknell, Berkshire, United Kingdom
| | - Paul J Rawlinson
- Department of Toxicology and Health Sciences, Syngenta Ltd, Jealott's Hill International Research Centre, Bracknell, Berkshire, United Kingdom
| | - Priscila Maria Fagundes
- Department of Product Safety, Syngenta Protecao de Cultivos Ltda, Sao Paulo, SP, 04795-900, Brazil
| | - Kevin A Leiner
- Department of Toxicology and Health Sciences, Syngenta Crop Protection LLC, Research Triangle Park, North Carolina
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36
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Dearfield KL, Gollapudi BB, Bemis JC, Benz RD, Douglas GR, Elespuru RK, Johnson GE, Kirkland DJ, LeBaron MJ, Li AP, Marchetti F, Pottenger LH, Rorije E, Tanir JY, Thybaud V, van Benthem J, Yauk CL, Zeiger E, Luijten M. Next generation testing strategy for assessment of genomic damage: A conceptual framework and considerations. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2017; 58:264-283. [PMID: 27650663 DOI: 10.1002/em.22045] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 08/08/2016] [Indexed: 06/06/2023]
Abstract
For several decades, regulatory testing schemes for genetic damage have been standardized where the tests being utilized examined mutations and structural and numerical chromosomal damage. This has served the genetic toxicity community well when most of the substances being tested were amenable to such assays. The outcome from this testing is usually a dichotomous (yes/no) evaluation of test results, and in many instances, the information is only used to determine whether a substance has carcinogenic potential or not. Over the same time period, mechanisms and modes of action (MOAs) that elucidate a wider range of genomic damage involved in many adverse health outcomes have been recognized. In addition, a paradigm shift in applied genetic toxicology is moving the field toward a more quantitative dose-response analysis and point-of-departure (PoD) determination with a focus on risks to exposed humans. This is directing emphasis on genomic damage that is likely to induce changes associated with a variety of adverse health outcomes. This paradigm shift is moving the testing emphasis for genetic damage from a hazard identification only evaluation to a more comprehensive risk assessment approach that provides more insightful information for decision makers regarding the potential risk of genetic damage to exposed humans. To enable this broader context for examining genetic damage, a next generation testing strategy needs to take into account a broader, more flexible approach to testing, and ultimately modeling, of genomic damage as it relates to human exposure. This is consistent with the larger risk assessment context being used in regulatory decision making. As presented here, this flexible approach for examining genomic damage focuses on testing for relevant genomic effects that can be, as best as possible, associated with an adverse health effect. The most desired linkage for risk to humans would be changes in loci associated with human diseases, whether in somatic or germ cells. The outline of a flexible approach and associated considerations are presented in a series of nine steps, some of which can occur in parallel, which was developed through a collaborative effort by leading genetic toxicologists from academia, government, and industry through the International Life Sciences Institute (ILSI) Health and Environmental Sciences Institute (HESI) Genetic Toxicology Technical Committee (GTTC). The ultimate goal is to provide quantitative data to model the potential risk levels of substances, which induce genomic damage contributing to human adverse health outcomes. Any good risk assessment begins with asking the appropriate risk management questions in a planning and scoping effort. This step sets up the problem to be addressed (e.g., broadly, does genomic damage need to be addressed, and if so, how to proceed). The next two steps assemble what is known about the problem by building a knowledge base about the substance of concern and developing a rational biological argument for why testing for genomic damage is needed or not. By focusing on the risk management problem and potential genomic damage of concern, the next step of assay(s) selection takes place. The work-up of the problem during the earlier steps provides the insight to which assays would most likely produce the most meaningful data. This discussion does not detail the wide range of genomic damage tests available, but points to types of testing systems that can be very useful. Once the assays are performed and analyzed, the relevant data sets are selected for modeling potential risk. From this point on, the data are evaluated and modeled as they are for any other toxicology endpoint. Any observed genomic damage/effects (or genetic event(s)) can be modeled via a dose-response analysis and determination of an estimated PoD. When a quantitative risk analysis is needed for decision making, a parallel exposure assessment effort is performed (exposure assessment is not detailed here as this is not the focus of this discussion; guidelines for this assessment exist elsewhere). Then the PoD for genomic damage is used with the exposure information to develop risk estimations (e.g., using reference dose (RfD), margin of exposure (MOE) approaches) in a risk characterization and presented to risk managers for informing decision making. This approach is applicable now for incorporating genomic damage results into the decision-making process for assessing potential adverse outcomes in chemically exposed humans and is consistent with the ILSI HESI Risk Assessment in the 21st Century (RISK21) roadmap. This applies to any substance to which humans are exposed, including pharmaceuticals, agricultural products, food additives, and other chemicals. It is time for regulatory bodies to incorporate the broader knowledge and insights provided by genomic damage results into the assessments of risk to more fully understand the potential of adverse outcomes in chemically exposed humans, thus improving the assessment of risk due to genomic damage. The historical use of genomic damage data as a yes/no gateway for possible cancer risk has been too narrowly focused in risk assessment. The recent advances in assaying for and understanding genomic damage, including eventually epigenetic alterations, obviously add a greater wealth of information for determining potential risk to humans. Regulatory bodies need to embrace this paradigm shift from hazard identification to quantitative analysis and to incorporate the wider range of genomic damage in their assessments of risk to humans. The quantitative analyses and methodologies discussed here can be readily applied to genomic damage testing results now. Indeed, with the passage of the recent update to the Toxic Substances Control Act (TSCA) in the US, the new generation testing strategy for genomic damage described here provides a regulatory agency (here the US Environmental Protection Agency (EPA), but suitable for others) a golden opportunity to reexamine the way it addresses risk-based genomic damage testing (including hazard identification and exposure). Environ. Mol. Mutagen. 58:264-283, 2017. © 2016 The Authors. Environmental and Molecular Mutagenesis Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Kerry L Dearfield
- U.S. Department of Agriculture, Food Safety and Inspection Service, Washington, District of Columbia
| | - B Bhaskar Gollapudi
- Exponent® Inc, Center for Toxicology and Mechanistic Biology, Midland, Michigan
| | | | | | - George R Douglas
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Rosalie K Elespuru
- U.S. Food and Drug Administration, CDRH/OSEL DBCMS, Silver Spring, Maryland
| | - George E Johnson
- Institute of Life Science, College of Medicine, Swansea University, Swansea, SA2 8PP, United Kingdom
| | | | - Matthew J LeBaron
- The Dow Chemical Company, Molecular, Cellular, and Biochemical Toxicology, Midland, Michigan
| | - Albert P Li
- In Vitro ADMET Laboratories LLC, Columbia, Maryland
| | - Francesco Marchetti
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Lynn H Pottenger
- Formerly of The Dow Chemical Company, Toxicology & Environmental Research and Consulting now with Olin Corporation, Midland, Michigan
| | - Emiel Rorije
- National Institute for Public Health and the Environment (RIVM), Center for Safety of Substances and Products, Bilthoven, 3720 BA, The Netherlands
| | - Jennifer Y Tanir
- ILSI Health and Environmental Sciences Institute (HESI), Washington, District of Columbia
| | - Veronique Thybaud
- Sanofi, Drug Disposition, Safety and Animal Research, Vitry-sur-Seine, France
| | - Jan van Benthem
- National Institute for Public Health and the Environment (RIVM), Center for Health Protection, Bilthoven, 3720 BA, The Netherlands
| | - Carole L Yauk
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Errol Zeiger
- Errol Zeiger Consulting, Chapel Hill, North Carolina
| | - Mirjam Luijten
- National Institute for Public Health and the Environment (RIVM), Center for Health Protection, Bilthoven, 3720 BA, The Netherlands
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Bryce SM, Bernacki DT, Bemis JC, Spellman RA, Engel ME, Schuler M, Lorge E, Heikkinen PT, Hemmann U, Thybaud V, Wilde S, Queisser N, Sutter A, Zeller A, Guérard M, Kirkland D, Dertinger SD. Interlaboratory evaluation of a multiplexed high information content in vitro genotoxicity assay. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2017; 58:146-161. [PMID: 28370322 PMCID: PMC5436310 DOI: 10.1002/em.22083] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 02/27/2017] [Accepted: 02/28/2017] [Indexed: 05/18/2023]
Abstract
We previously described a multiplexed in vitro genotoxicity assay based on flow cytometric analysis of detergent-liberated nuclei that are simultaneously stained with propidium iodide and labeled with fluorescent antibodies against p53, γH2AX, and phospho-histone H3. Inclusion of a known number of microspheres provides absolute nuclei counts. The work described herein was undertaken to evaluate the interlaboratory transferability of this assay, commercially known as MultiFlow® DNA Damage Kit-p53, γH2AX, Phospho-Histone H3. For these experiments, seven laboratories studied reference chemicals from a group of 84 representing clastogens, aneugens, and nongenotoxicants. TK6 cells were exposed to chemicals in 96-well plates over a range of concentrations for 24 hr. At 4 and 24 hr, cell aliquots were added to the MultiFlow reagent mix and following a brief incubation period flow cytometric analysis occurred, in most cases directly from a 96-well plate via a robotic walk-away data acquisition system. Multiplexed response data were evaluated using two analysis approaches, one based on global evaluation factors (i.e., cutoff values derived from all interlaboratory data), and a second based on multinomial logistic regression that considers multiple biomarkers simultaneously. Both data analysis strategies were devised to categorize chemicals as predominately exhibiting a clastogenic, aneugenic, or nongenotoxic mode of action (MoA). Based on the aggregate 231 experiments that were performed, assay sensitivity, specificity, and concordance in relation to a priori MoA grouping were ≥ 92%. These results are encouraging as they suggest that two distinct data analysis strategies can rapidly and reliably predict new chemicals' predominant genotoxic MoA based on data from an efficient and transferable multiplexed in vitro assay. Environ. Mol. Mutagen. 58:146-161, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
| | | | | | | | - Maria E Engel
- Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Maik Schuler
- Pfizer Worldwide Research and Development, Groton, Connecticut
| | | | | | | | | | | | | | | | - Andreas Zeller
- Roche Pharma Research and Early Development, Basel, Switzerland
| | - Melanie Guérard
- Roche Pharma Research and Early Development, Basel, Switzerland
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Rees BJ, Tate M, Lynch AM, Thornton CA, Jenkins GJ, Walmsley RM, Johnson GE. Development of an in vitro PIG-A gene mutation assay in human cells. Mutagenesis 2017; 32:283-297. [PMID: 28057708 PMCID: PMC5907909 DOI: 10.1093/mutage/gew059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 11/15/2016] [Indexed: 11/12/2022] Open
Abstract
Mutagens can be carcinogens, and traditionally, they have been identified in vitro using the Salmonella 'Ames' reverse mutation assay. However, prokaryotic DNA packaging, replication and repair systems are mechanistically very different to those in the humans we inevitably seek to protect. Therefore, for many years, mammalian cell line genotoxicity assays that can detect eukaryotic mutagens as well as clastogens and aneugens have been used. The apparent lack of specificity in these largely rodent systems, due partly to their mutant p53 status, has contributed to the use of animal studies to resolve data conflicts. Recently, silencing mutations at the PIG-A locus have been demonstrated to prevent glycophosphatidylinositol (GPI) anchor synthesis and consequentially result in loss of GPI-anchored proteins from the cell's extracellular surface. The successful exploitation of this mutant phenotype in animal studies has triggered interest in the development of an analogous in vitro PIG-A mutation screening assay. This article describes the development of a robust assay design using metabolically active human cells. The assay includes viability and cell membrane integrity assessment and conforms to the future ideas of the 21st-century toxicology testing.
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Affiliation(s)
- Benjamin J Rees
- Institute of Life Science, Swansea University Medical School, Singleton Park, Swansea, UK
| | - Matthew Tate
- Gentronix Ltd BioHub at Alderley Park, Alderley Edge, Cheshire, UK
| | | | - Catherine A Thornton
- Institute of Life Science, Swansea University Medical School, Singleton Park, Swansea, UK
| | - Gareth J Jenkins
- Institute of Life Science, Swansea University Medical School, Singleton Park, Swansea, UK
| | - Richard M Walmsley
- Gentronix Ltd BioHub at Alderley Park, Alderley Edge, Cheshire, UK
- Faculty of Life Sciences, University of Manchester, Manchester, UK
| | - George E Johnson
- Institute of Life Science, Swansea University Medical School, Singleton Park, Swansea, UK
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Kimoto T, Horibata K, Miura D, Chikura S, Okada Y, Ukai A, Itoh S, Nakayama S, Sanada H, Koyama N, Muto S, Uno Y, Yamamoto M, Suzuki Y, Fukuda T, Goto K, Wada K, Kyoya T, Shigano M, Takasawa H, Hamada S, Adachi H, Uematsu Y, Tsutsumi E, Hori H, Kikuzuki R, Ogiwara Y, Yoshida I, Maeda A, Narumi K, Fujiishi Y, Morita T, Yamada M, Honma M. The PIGRET assay, a method for measuring Pig-a gene mutation in reticulocytes, is reliable as a short-term in vivo genotoxicity test: Summary of the MMS/JEMS-collaborative study across 16 laboratories using 24 chemicals. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2016; 811:3-15. [DOI: 10.1016/j.mrgentox.2016.10.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 10/18/2016] [Indexed: 10/20/2022]
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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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Williams GM, Aardema M, Acquavella J, Berry SC, Brusick D, Burns MM, de Camargo JLV, Garabrant D, Greim HA, Kier LD, Kirkland DJ, Marsh G, Solomon KR, Sorahan T, Roberts A, Weed DL. A review of the carcinogenic potential of glyphosate by four independent expert panels and comparison to the IARC assessment. Crit Rev Toxicol 2016; 46:3-20. [DOI: 10.1080/10408444.2016.1214677] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Gary M. Williams
- Department of Pathology, New York Medical College, Valhalla, NY, USA
| | | | - John Acquavella
- Department of Clinical Epidemiology, Aarhus University, Aarhus, Denmark
| | - Sir Colin Berry
- Department of Pathology, Queen Mary, University of London, London, UK
| | | | | | | | - David Garabrant
- Department of Occupational Medicine and Epidemiology, EpidStat Institute, University of Michigan, Ann Arbor, MI, USA
| | - Helmut A. Greim
- Department of Toxicology and Environmental Hygiene, Technical University of Munich, Munich, Germany
| | | | | | - Gary Marsh
- Department of Biostatistics, Center for Occupational Biostatistics & Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Tom Sorahan
- Department of Occupational Epidemiology, University of Birmingham, Birmingham, UK
| | - Ashley Roberts
- Intertek Regulatory & Scientific Consultancy, Mississauga, ON, Canada
| | - Douglas L. Weed
- DLW Consulting Services, LLC, University of New Mexico School of Medicine, Albuquerque, NM, USA
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Akyıl D, Eren Y, Konuk M, Tepekozcan A, Sağlam E. Determination of mutagenicity and genotoxicity of indium tin oxide nanoparticles using the Ames test and micronucleus assay. Toxicol Ind Health 2016; 32:1720-8. [DOI: 10.1177/0748233715579804] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In this study, the mutagenicity and genotoxicity of indium tin oxide (ITO) nanomaterial were assessed using two standard genotoxicity assays, the Salmonella reverse mutation assay (Ames test) and the in vitro micronucleus (MN) assay. Seven different concentrations (12.5, 25, 50, 75, 100, 125, and 150 µg/plate) of this nanomaterial were tested using the Ames test on the TA98 and TA100 strains in the presence and absence of the S9 mixture. At all the concentrations tested, this substance did not significantly increase the number of revertant colonies compared with the control with or without S9 mixture. The genotoxic effects of ITO were investigated in human peripheral lymphocytes treated with 125, 250, 500, and 750 µg/ml concentrations of this substance for 24- and 48-h treatment periods using an MN test. Nuclear division index (NDI) was also calculated in order to determine the cytotoxicity of ITO. It was determined that ITO increased MN frequency in the 750 µg/ml concentration in 24- and 48-h treatments. In addition, ITO dose dependently decreased the NDI significantly for two treatment periods.
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Affiliation(s)
- Dilek Akyıl
- Department of Biology, Faculty of Science and Literatures, Afyon Kocatepe University, Afyonkarahisar, Turkey
| | - Yasin Eren
- Department of Science Education, Faculty of Education, Suleyman Demirel University, Isparta, Turkey
| | - Muhsin Konuk
- Department of Molecular Biology and Genetics, Faculty of Engineering and Natural Sciences, Üsküdar University, Altunizade, Istanbul, Turkey
| | - Aykut Tepekozcan
- Department of Biology, Faculty of Science and Literatures, Afyon Kocatepe University, Afyonkarahisar, Turkey
| | - Esra Sağlam
- Department of Molecular Biology and Genetics, Faculty of Engineering and Natural Sciences, Üsküdar University, Altunizade, Istanbul, Turkey
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Casalegno M, Sello G. Carcinogenicity prediction of noncongeneric chemicals by augmented top priority fragment classification. Comput Biol Chem 2016; 61:145-54. [DOI: 10.1016/j.compbiolchem.2016.01.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 12/15/2015] [Accepted: 01/26/2016] [Indexed: 10/22/2022]
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Roberts DJ, McKeon M, Xu Y, Stankowski LF. Comparison of integrated genotoxicity endpoints in rats after acute and subchronic oral doses of 4-nitroquinoline-1-oxide. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2016; 57:17-27. [PMID: 26407646 PMCID: PMC7362388 DOI: 10.1002/em.21981] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 08/17/2015] [Indexed: 05/16/2023]
Abstract
During interlaboratory validation trials for the Pig-a gene mutation assay we assessed the genotoxicity of 4-nitroquinoline-1-oxide (4NQO) across endpoints in multiple tissues: induction of Pig-a mutant red blood cells (RBCs) and reticulocytes (RETs); micronucleated RETs (MN RETs); and DNA damage in blood and liver via the alkaline Comet assay (%tail intensity [TI]). In a previous subchronic toxicity study with 28 daily doses, biologically meaningful increases were observed only for Pig-a mutant RBCs/RETs while marginal increases in the frequency of MN RET were observed, and other clastogenic endpoints were negative. Follow up acute studies were performed using the same cumulative doses (0, 35, 70, 105, and 140 mg/kg) administered in a bolus, or split over three equal daily doses, with samples collected up to 1 month after the last dose. Both of the acute dosing regimens produced similar results, in that endpoints were either positive or negative, regardless of 1 or 3 daily doses, but the three consecutive daily dose regimen yielded more potent responses in TI (in liver and blood) and Pig-a mutant frequencies. In these acute studies the same cumulative doses of 4NQO induced positive responses in clastogenic endpoints that were negative or inconclusive using a subchronic study design. Additionally, a positive control group using combination doses of cyclophosphamide and ethyl methanesulfonate was employed to assess assay validity and potentially identify a future positive control treatment for integrated genetic toxicity studies.
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Affiliation(s)
- Daniel J Roberts
- Bristol-Myers Squibb, New Brunswick, NJ, USA
- Joint Graduate Program of Toxicology, Rutgers, NJ, USA
| | | | - Yong Xu
- BioReliance Corporation, Rockville, MD, USA
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Siqian L, Lei S, Ying L. Development of a cellular biosensor system for genotoxicity detection based on Trp53 promoter. Hum Exp Toxicol 2015; 35:1102-7. [PMID: 26721909 DOI: 10.1177/0960327115621364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE To develop a mouse cell biosensor system for the high-throughput genotoxicity detection of chemicals, such as environmental pollutants. METHOD We developed a novel reporter vector pGL4-GFP, wherein the firefly luciferase reporter gene in the pGL4.82 vector was replaced by the green fluorescent protein (GFP) gene from the pAcGFP1-N1 vector. To construct the reporter pGL4-p53-GFP (p53 promoter linked to GFP), a fragment containing the p53 gene promoter was generated by amplifying a region from -481 to +180 of mouse genomic DNA isolated from mouse tail tissue. We developed a mouse cell biosensor system for the high-throughput genotoxicity detection of new drugs by stably integrating the reporter plasmid of pGL4-p53-GFP into the mouse embryonic fibroblast cells. Various genotoxic agents were used to treat this biosensor system. The resulting fluorescence was directly observed under a fluorescence microscope, and the GFP protein level was measured through Western blot analysis. RESULT The biosensor system was treated with genotoxic agents, such as doxorubicin, cyclophosphamide, and benzo(a)pyrene. The GFP protein expression was significantly increased in cells exposed to genotoxic agents but negatively responded to the non-genotoxic agent dimethyl sulfoxide, thereby proving the specificity and sensitivity of the biosensor system. CONCLUSION This novel in vitro biosensor system can be especially useful in genotoxicity detection.
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Affiliation(s)
- L Siqian
- Laboratory of Molecular Genetics of Aging and Tumor, Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan, China
| | - S Lei
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan, China
| | - L Ying
- Laboratory of Molecular Genetics of Aging and Tumor, Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan, China
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Petkov PI, Patlewicz G, Schultz TW, Honma M, Todorov M, Kotov S, Dimitrov SD, Donner EM, Mekenyan OG. A feasibility study: Can information collected to classify for mutagenicity be informative in predicting carcinogenicity? Regul Toxicol Pharmacol 2015; 72:17-25. [DOI: 10.1016/j.yrtph.2015.03.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 03/06/2015] [Accepted: 03/07/2015] [Indexed: 01/22/2023]
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Guichard Y, Maire MA, Sébillaud S, Fontana C, Langlais C, Micillino JC, Darne C, Roszak J, Stępnik M, Fessard V, Binet S, Gaté L. Genotoxicity of synthetic amorphous silica nanoparticles in rats following short-term exposure. Part 2: intratracheal instillation and intravenous injection. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2015; 56:228-244. [PMID: 25451515 DOI: 10.1002/em.21928] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 11/03/2014] [Accepted: 11/05/2014] [Indexed: 06/04/2023]
Abstract
Synthetic amorphous silica nanomaterials (SAS) are extensively used in food and tire industries. In many industrial processes, SAS may become aerosolized and lead to occupational exposure of workers through inhalation in particular. However, little is known about the in vivo genotoxicity of these particulate materials. To gain insight into the toxicological properties of four SAS (NM-200, NM-201, NM-202, and NM-203), rats are treated with three consecutive intratracheal instillations of 3, 6, or 12 mg/kg of SAS at 48, 24, and 3 hrs prior to tissue collection (cumulative doses of 9, 18, and 36 mg/kg). Deoxyribonucleic acid (DNA) damage was assessed using erythrocyte micronucleus test and the standard and Fpg-modified comet assays on cells from bronchoalveolar lavage fluid (BALF), lung, blood, spleen, liver, bone marrow, and kidney. Although all of the SAS caused increased dose-dependent changes in lung inflammation as demonstrated by BALF neutrophilia, they did not induce any significant DNA damage. As the amount of SAS reaching the blood stream and subsequently the internal organs is probably to be low following intratracheal instillation, an additional experiment was performed with NM-203. Rats received three consecutive intravenous injections of 5, 10, or 20 mg/kg of SAS at 48, 24, and 3 hrs prior to tissue collection. Despite the hepatotoxicity, thrombocytopenia, and even animal death induced by this nanomaterial, no significant increase in DNA damage or micronucleus frequency was observed in SAS-exposed animals. It was concluded that under experimental conditions, SAS induced obvious toxic effects but did cause any genotoxicity following intratracheal instillation and intravenous injection.
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Affiliation(s)
- Yves Guichard
- INRS, Institut National de Recherche et de Sécurité, Département Toxicologie et Biométrologie, Rue du Morvan, CS 60027, 54519, Vandoeuvre les Nancy Cedex, France
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Yauk CL, Aardema MJ, Benthem JV, Bishop JB, Dearfield KL, DeMarini DM, Dubrova YE, Honma M, Lupski JR, Marchetti F, Meistrich ML, Pacchierotti F, Stewart J, Waters MD, Douglas GR. Approaches for identifying germ cell mutagens: Report of the 2013 IWGT workshop on germ cell assays(☆). MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2015; 783:36-54. [PMID: 25953399 DOI: 10.1016/j.mrgentox.2015.01.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 01/23/2015] [Indexed: 01/06/2023]
Abstract
This workshop reviewed the current science to inform and recommend the best evidence-based approaches on the use of germ cell genotoxicity tests. The workshop questions and key outcomes were as follows. (1) Do genotoxicity and mutagenicity assays in somatic cells predict germ cell effects? Limited data suggest that somatic cell tests detect most germ cell mutagens, but there are strong concerns that dictate caution in drawing conclusions. (2) Should germ cell tests be done, and when? If there is evidence that a chemical or its metabolite(s) will not reach target germ cells or gonadal tissue, it is not necessary to conduct germ cell tests, notwithstanding somatic outcomes. However, it was recommended that negative somatic cell mutagens with clear evidence for gonadal exposure and evidence of toxicity in germ cells could be considered for germ cell mutagenicity testing. For somatic mutagens that are known to reach the gonadal compartments and expose germ cells, the chemical could be assumed to be a germ cell mutagen without further testing. Nevertheless, germ cell mutagenicity testing would be needed for quantitative risk assessment. (3) What new assays should be implemented and how? There is an immediate need for research on the application of whole genome sequencing in heritable mutation analysis in humans and animals, and integration of germ cell assays with somatic cell genotoxicity tests. Focus should be on environmental exposures that can cause de novo mutations, particularly newly recognized types of genomic changes. Mutational events, which may occur by exposure of germ cells during embryonic development, should also be investigated. Finally, where there are indications of germ cell toxicity in repeat dose or reproductive toxicology tests, consideration should be given to leveraging those studies to inform of possible germ cell genotoxicity.
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Affiliation(s)
- Carole L Yauk
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada.
| | | | - Jan van Benthem
- National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - Jack B Bishop
- National Institute of Environmental Health Sciences, NC, USA
| | | | | | | | | | - James R Lupski
- Department of Molecular and Human Genetics, and Department of Pediatrics, Baylor College of Medicine, USA
| | - Francesco Marchetti
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | | | - Francesca Pacchierotti
- ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Italy
| | | | | | - George R Douglas
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada.
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Claxton LD. The history, genotoxicity, and carcinogenicity of carbon-based fuels and their emissions: Part 5. Summary, comparisons, and conclusions. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2015; 763:103-47. [DOI: 10.1016/j.mrrev.2014.10.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 10/04/2014] [Accepted: 10/06/2014] [Indexed: 12/19/2022]
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Abstract
Nonclinical safety pharmacology and toxicology testing of drug candidates assess the potential adverse effects caused by the drug in relation to its intended use in humans. Hazards related to a drug have to be identified and the potential risks at the intended exposure have to be evaluated in comparison to the potential benefit of the drug. Preclinical safety is thus an integral part of drug discovery and drug development. It still causes significant attrition during drug development.Therefore, there is a need for smart selection of drug candidates in drug discovery including screening of important safety endpoints. In the recent years,there was significant progress in computational and in vitro technology allowing in silico assessment as well as high-throughput screening of some endpoints at very early stages of discovery. Despite all this progress, in vivo evaluation of drug candidates is still an important part to safety testing. The chapter provides an overview on the most important areas of nonclinical safety screening during drug discovery of small molecules.
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