1
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Snodin DJ, Trejo-Martin A, Ponting DJ, Smith GF, Czich A, Cross K, Custer L, Elloway J, Greene N, Kalgutkar AS, Stalford SA, Tennant RE, Vock E, Zalewski A, Ziegler V, Dobo KL. Mechanisms of Nitrosamine Mutagenicity and Their Relationship to Rodent Carcinogenic Potency. Chem Res Toxicol 2024; 37:181-198. [PMID: 38316048 DOI: 10.1021/acs.chemrestox.3c00327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
A thorough literature review was undertaken to understand how the pathways of N-nitrosamine transformation relate to mutagenic potential and carcinogenic potency in rodents. Empirical and computational evidence indicates that a common radical intermediate is created by CYP-mediated hydrogen abstraction at the α-carbon; it is responsible for both activation, leading to the formation of DNA-reactive diazonium species, and deactivation by denitrosation. There are competing sites of CYP metabolism (e.g., β-carbon), and other reactive species can form following initial bioactivation, although these alternative pathways tend to decrease rather than enhance carcinogenic potency. The activation pathway, oxidative dealkylation, is a common reaction in drug metabolism and evidence indicates that the carbonyl byproduct, e.g., formaldehyde, does not contribute to the toxic properties of N-nitrosamines. Nitric oxide (NO), a side product of denitrosation, can similarly be discounted as an enhancer of N-nitrosamine toxicity based on carcinogenicity data for substances that act as NO-donors. However, not all N-nitrosamines are potent rodent carcinogens. In a significant number of cases, there is a potency overlap with non-N-nitrosamine carcinogens that are not in the Cohort of Concern (CoC; high-potency rodent carcinogens comprising aflatoxin-like-, N-nitroso-, and alkyl-azoxy compounds), while other N-nitrosamines are devoid of carcinogenic potential. In this context, mutagenicity is a useful surrogate for carcinogenicity, as proposed in the ICH M7 (R2) (2023) guidance. Thus, in the safety assessment and control of N-nitrosamines in medicines, it is important to understand those complementary attributes of mechanisms of mutagenicity and structure-activity relationships that translate to elevated potency versus those which are associated with a reduction in, or absence of, carcinogenic potency.
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Affiliation(s)
| | - Alejandra Trejo-Martin
- Gilead Sciences Inc. Nonclinical Safety and Pathobiology (NSP), Foster City, California 94404, United States
| | | | - Graham F Smith
- AstraZeneca, Imaging and Data Analytics, Clinical Pharmacology and Safety Sciences, Research and Development, CB2 0AA Cambridge, U.K
| | - Andreas Czich
- Sanofi, Research and Development, Preclinical Safety, 65926 Frankfurt, Germany
| | - Kevin Cross
- Instem, Conshohocken, Pennsylvania 19428, United States
| | - Laura Custer
- Bristol-Myers Squibb, Nonclinical Safety, New Brunswick, New Jersey 08903, United States
| | - Joanne Elloway
- AstraZeneca, Safety Sciences, Clinical Pharmacology and Safety Sciences Research and Development, CB2 0AA Cambridge, U.K
| | - Nigel Greene
- AstraZeneca, Imaging and Data Analytics, Clinical Pharmacology and Safety Sciences, Research and Development, Waltham, Massachusetts 02451, United States
| | - Amit S Kalgutkar
- Medicine Design, Pfizer Worldwide Research, Development, and Medical, Cambridge, Massachusetts 02139, United States
| | | | | | - Esther Vock
- Boehringer-Ingelheim Pharma GmbH & Co., KG, 88397 Biberach an der Riss, Germany
| | - Adam Zalewski
- Bayer AG, Pharmaceuticals, Genetic and Computational Toxicology, 13342 Berlin, Germany
| | - Verena Ziegler
- Bayer AG, Pharmaceuticals, Genetic and Computational Toxicology, 13342 Berlin, Germany
| | - Krista L Dobo
- Drug Safety Research and Development, Global Portfolio and Regulatory Strategy, Pfizer Worldwide Research, Development, and Medical, Groton, Connecticut 06340, United States
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2
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Spiliotopoulos D, Koelbert C, Audebert M, Barisch I, Bellet D, Constans M, Czich A, Finot F, Gervais V, Khoury L, Kirchnawy C, Kitamoto S, Le Tesson A, Malesic L, Matsuyama R, Mayrhofer E, Mouche I, Preikschat B, Prielinger L, Rainer B, Roblin C, Wäse K. Assessment of the performance of the Ames MPF™ assay: A multicenter collaborative study with six coded chemicals. Mutat Res Genet Toxicol Environ Mutagen 2024; 893:503718. [PMID: 38272629 DOI: 10.1016/j.mrgentox.2023.503718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 11/06/2023] [Accepted: 11/19/2023] [Indexed: 01/27/2024]
Abstract
The Ames MPF™ is a miniaturized, microplate fluctuation format of the Ames test. It is a standardized, commercially available product which can be used to assess mutagenicity in Salmonella and E. coli strains in 384-well plates using a color change-based readout. Several peer-reviewed comparisons of the Ames MPF™ to the Ames test in Petri dishes confirmed its suitability to evaluate the mutagenic potential of a variety of test items. An international multicenter study involving seven laboratories tested six coded chemicals with this assay using five bacterial strains, as recommended by the OECD test guideline 471. The data generated by the participating laboratories was in excellent agreement (93%), and the similarity of their dose response curves, as analyzed with sophisticated statistical approaches further confirmed the suitability of the Ames MPF™ assay as an alternative to the Ames test on agar plates, but with advantages with respect to significantly reduced amount of test substance and S9 requirements, speed, hands-on time and, potentially automation.
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Affiliation(s)
| | | | - Marc Audebert
- PrediTox, 1 place Pierre Potier, 31100 Toulouse, France; INRAE UMR1331 Toxalim, 180 chemin de Tournefeuille, 31300 Toulouse, France
| | - Ilona Barisch
- Genetic Toxicology, Preclinical Safety, Sanofi-Aventis Deutschland GmbH, 65926 Frankfurt am Main, Germany
| | - Deborah Bellet
- GenEvolutioN, 2, 8 Rue de Rouen, 78440 Porcheville, France
| | | | - Andreas Czich
- Genetic Toxicology, Preclinical Safety, Sanofi-Aventis Deutschland GmbH, 65926 Frankfurt am Main, Germany
| | - Francis Finot
- GenEvolutioN, 2, 8 Rue de Rouen, 78440 Porcheville, France
| | - Véronique Gervais
- Servier Group, Non-Clinical Safety Department, F-45403 Orléans-Gidy, France
| | - Laure Khoury
- PrediTox, 1 place Pierre Potier, 31100 Toulouse, France
| | - Christian Kirchnawy
- OFI, Austrian Research Institute for Chemistry and Technology, Department for Microbiology and Cell Culture, Franz-Grill Straße 5, Objekt 213, 1030 Vienna, Austria
| | - Sachiko Kitamoto
- Environmental Health Science Laboratory, Sumitomo Chemical Co., Ltd., 1-98, Kasugadenaka 3-chome, konohana-ku, Osaka, Japan
| | - Audrey Le Tesson
- Servier Group, Non-Clinical Safety Department, F-45403 Orléans-Gidy, France
| | - Laure Malesic
- GenEvolutioN, 2, 8 Rue de Rouen, 78440 Porcheville, France
| | - Ryoko Matsuyama
- Environmental Health Science Laboratory, Sumitomo Chemical Co., Ltd., 1-98, Kasugadenaka 3-chome, konohana-ku, Osaka, Japan
| | - Elisa Mayrhofer
- OFI, Austrian Research Institute for Chemistry and Technology, Department for Microbiology and Cell Culture, Franz-Grill Straße 5, Objekt 213, 1030 Vienna, Austria
| | | | - Birgit Preikschat
- Genetic Toxicology, Preclinical Safety, Sanofi-Aventis Deutschland GmbH, 65926 Frankfurt am Main, Germany
| | - Lukas Prielinger
- Department of Applied Life Sciences, University of Applied Sciences, FH Campus Wien, Favoritenstraße 222, 1100 Vienna, Austria
| | - Bernhard Rainer
- Department of Applied Life Sciences, University of Applied Sciences, FH Campus Wien, Favoritenstraße 222, 1100 Vienna, Austria
| | - Clémence Roblin
- Servier Group, Non-Clinical Safety Department, F-45403 Orléans-Gidy, France
| | - Kerstin Wäse
- Genetic Toxicology, Preclinical Safety, Sanofi-Aventis Deutschland GmbH, 65926 Frankfurt am Main, Germany
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3
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Bercu JP, Masuda-Herrera M, Trejo-Martin A, Sura P, Jolly R, Kenyon M, Thomas R, Ponting DJ, Snodin D, Tuschl G, Simon S, De Vlieger K, Hutchinson R, Czich A, Glowienke S, Reddy MV, Johanssen S, Vock E, Claude N, Weaver RJ. Acceptable Intakes (AIs) for 11 Small molecule N-nitrosamines (NAs). Regul Toxicol Pharmacol 2023:105415. [PMID: 37257751 DOI: 10.1016/j.yrtph.2023.105415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/21/2023] [Accepted: 05/07/2023] [Indexed: 06/02/2023]
Abstract
Low levels of N-nitrosamines (NAs) were detected in pharmaceuticals and, as a result, health authorities (HAs) have published acceptable intakes (AIs) in pharmaceuticals to limit potential carcinogenic risk. The rationales behind the AIs have not been provided to understand the process for selecting a TD50 or read-across analog. In this manuscript we evaluated the toxicity data for eleven common NAs in a comprehensive and transparent process consistent with ICH M7. This evaluation included substances which had datasets that were robust, limited but sufficient, and substances with insufficient experimental animal carcinogenicity data. In the case of robust or limited but sufficient carcinogenicity information, AIs were calculated based on published or derived TD50s from the most sensitive organ site. In the case of insufficient carcinogenicity information, available carcinogenicity data and structure activity relationships (SARs) were applied to categorical-based AIs of 1500 ng/day, 150 ng/day or 18 ng/day; however additional data (such as biological or additional computational modelling) could inform an alternative AI. This approach advances the methodology used to derive AIs for NAs.
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Affiliation(s)
- Joel P Bercu
- Gilead Sciences, Inc., Nonclinical Safety and Pathobiology (NSP), Foster City, CA, USA.
| | - Melisa Masuda-Herrera
- Gilead Sciences, Inc., Nonclinical Safety and Pathobiology (NSP), Foster City, CA, USA
| | | | - Priyanka Sura
- Gilead Sciences, Inc., Nonclinical Safety and Pathobiology (NSP), Foster City, CA, USA
| | | | - Michelle Kenyon
- Pfizer Worldwide Research, Development and Medical, Drug Safety Research and Development, Eastern Point Road, Groton, CT, USA
| | - Rob Thomas
- Lhasa Limited, Granary Wharf House, 2 Canal Wharf, Leeds, UK
| | - David J Ponting
- Lhasa Limited, Granary Wharf House, 2 Canal Wharf, Leeds, UK
| | | | - Gregor Tuschl
- Merck KGaA, Global Chemical and Preclinical Safety, Darmstadt, Germany
| | - Stephanie Simon
- Merck KGaA, Global Chemical and Preclinical Safety, Darmstadt, Germany
| | | | | | | | | | | | - Sandra Johanssen
- Bayer AG, Pharmaceuticals, Research & Development, Berlin, Germany
| | - Esther Vock
- Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str., Biberach an der Riss, Germany
| | - Nancy Claude
- Servier Paris-Saclay R&D Institute, Gif-sur-Yvette, France
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4
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Pognan F, Beilmann M, Boonen HCM, Czich A, Dear G, Hewitt P, Mow T, Oinonen T, Roth A, Steger-Hartmann T, Valentin JP, Van Goethem F, Weaver RJ, Newham P. The evolving role of investigative toxicology in the pharmaceutical industry. Nat Rev Drug Discov 2023; 22:317-335. [PMID: 36781957 PMCID: PMC9924869 DOI: 10.1038/s41573-022-00633-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/16/2022] [Indexed: 02/15/2023]
Abstract
For decades, preclinical toxicology was essentially a descriptive discipline in which treatment-related effects were carefully reported and used as a basis to calculate safety margins for drug candidates. In recent years, however, technological advances have increasingly enabled researchers to gain insights into toxicity mechanisms, supporting greater understanding of species relevance and translatability to humans, prediction of safety events, mitigation of side effects and development of safety biomarkers. Consequently, investigative (or mechanistic) toxicology has been gaining momentum and is now a key capability in the pharmaceutical industry. Here, we provide an overview of the current status of the field using case studies and discuss the potential impact of ongoing technological developments, based on a survey of investigative toxicologists from 14 European-based medium-sized to large pharmaceutical companies.
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Affiliation(s)
- Francois Pognan
- Discovery and Investigative Safety, Novartis Pharma AG, Basel, Switzerland.
| | - Mario Beilmann
- Nonclinical Drug Safety Germany, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Harrie C M Boonen
- Drug Safety, Dept of Exploratory Toxicology, Lundbeck A/S, Valby, Denmark
| | | | - Gordon Dear
- In Vitro In Vivo Translation, GlaxoSmithKline David Jack Centre for Research, Ware, UK
| | - Philip Hewitt
- Chemical and Preclinical Safety, Merck Healthcare KGaA, Darmstadt, Germany
| | - Tomas Mow
- Safety Pharmacology and Early Toxicology, Novo Nordisk A/S, Maaloev, Denmark
| | - Teija Oinonen
- Preclinical Safety, Orion Corporation, Espoo, Finland
| | - Adrian Roth
- Pharmaceutical Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | | | | | - Freddy Van Goethem
- Predictive, Investigative & Translational Toxicology, Nonclinical Safety, Janssen Research & Development, Beerse, Belgium
| | - Richard J Weaver
- Innovation Life Cycle Management, Institut de Recherches Internationales Servier, Suresnes, France
| | - Peter Newham
- Clinical Pharmacology and Safety Sciences, AstraZeneca R&D, Cambridge, UK.
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5
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Wenzel J, Schmidt F, Blumrich M, Amberg A, Czich A. Predicting DNA-Reactivity of N-Nitrosamines: A Quantum Chemical Approach. Chem Res Toxicol 2022; 35:2068-2084. [PMID: 36302168 DOI: 10.1021/acs.chemrestox.2c00217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
N-Nitrosamines (NAs) are a class of reactive organic chemicals that humans may be exposed to from environmental sources, food but also impurities in pharmaceutical preparations. Some NAs were identified as DNA-reactive mutagens and many of those have been classified as probable human carcinogens. Beyond high-potency mutagenic carcinogens that need to be strictly controlled, NAs of low potency need to be considered for risk assessment as well. NA impurities and nitrosylated products of active pharmaceutical ingredients (APIs) often arise from production processes or degradation. Most NAs require metabolic activation to ultimately become carcinogens, and their activation can be appropriately described by first-principles computational chemistry approaches. To this end, we treat NA-induced DNA alkylation as a series of subsequent association and dissociation reaction steps that can be calculated stringently by density functional theory (DFT), including α-hydroxylation, proton transfer, hydroxyl elimination, direct SN2/SNAr DNA alkylation, competing hydrolysis and SN1 reactions. Both toxification and detoxification reactions are considered. The activation reactions are modeled by DFT at a high level of theory with an appropriate solvent model to compute Gibbs free energies of the reactions (thermodynamical effects) and activation barriers (kinetic effects). We study congeneric series of aliphatic and cyclic NAs to identify trends. Overall, this work reveals detailed insight into mechanisms of activation for NAs, suggesting that individual steric and electronic factors have directing and rate-determining influence on the formation of carbenium ions as the ultimate pro-mutagens and thus carcinogens. Therefore, an individual risk assessment of NAs is suggested, as exemplified for the complex API-like 4-(N-nitroso-N-methyl)aminoantipyrine which is considered as low-potency NA by in silico prediction.
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Affiliation(s)
- Jan Wenzel
- Sanofi, R&D, Preclinical Safety, Industriepark Höchst, Industriepark Höchst, 65926Frankfurt am Main, Germany
| | - Friedemann Schmidt
- Sanofi, R&D, Preclinical Safety, Industriepark Höchst, Industriepark Höchst, 65926Frankfurt am Main, Germany
| | - Matthias Blumrich
- Sanofi, R&D, Preclinical Safety, Industriepark Höchst, Industriepark Höchst, 65926Frankfurt am Main, Germany
| | - Alexander Amberg
- Sanofi, R&D, Preclinical Safety, Industriepark Höchst, Industriepark Höchst, 65926Frankfurt am Main, Germany
| | - Andreas Czich
- Sanofi, R&D, Preclinical Safety, Industriepark Höchst, Industriepark Höchst, 65926Frankfurt am Main, Germany
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6
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Trejo-Martin A, Bercu JP, Thresher A, Tennant RE, Thomas RF, Cross K, Czich A, Waese K, Nicolette JJ, Murray J, Sonders P, Kondratiuk A, Cheung JR, Thomas D, Lynch A, Harvey J, Glowienke S, Custer L, Escobar PA. Use of the bacterial reverse mutation assay to predict carcinogenicity of N-nitrosamines. Regul Toxicol Pharmacol 2022; 135:105247. [PMID: 35998738 DOI: 10.1016/j.yrtph.2022.105247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 08/08/2022] [Accepted: 08/12/2022] [Indexed: 11/29/2022]
Abstract
Under ICH M7, impurities are assessed using the bacterial reverse mutation assay (i.e., Ames test) when predicted positive using in silico methodologies followed by expert review. N-Nitrosamines (NAs) have been of recent concern as impurities in pharmaceuticals, mainly because of their potential to be highly potent mutagenic carcinogens in rodent bioassays. The purpose of this analysis was to determine the sensitivity of the Ames assay to predict the carcinogenic outcome with curated proprietary Vitic (n = 131) and Leadscope (n = 70) databases. NAs were selected if they had corresponding rodent carcinogenicity assays. Overall, the sensitivity/specificity of the Ames assay was 93-97% and 55-86%, respectively. The sensitivity of the Ames assay was not significantly impacted by plate incorporation (84-89%) versus preincubation (82-89%). Sensitivity was not significantly different between use of rat and hamster liver induced S9 (80-93% versus 77-96%). The sensitivity of the Ames is high when using DMSO as a solvent (87-88%). Based on the analysis of these databases, the Ames assay conducted under OECD 471 guidelines is highly sensitive for detecting the carcinogenic hazards of NAs.
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Affiliation(s)
- Alejandra Trejo-Martin
- Gilead Sciences, Inc., Nonclinical Safety and Pathobiology (NSP), Foster City, CA, 94404, USA.
| | - Joel P Bercu
- Gilead Sciences, Inc., Nonclinical Safety and Pathobiology (NSP), Foster City, CA, 94404, USA
| | - Andrew Thresher
- Lhasa Limited, Granary Wharf House, 2 Canal Wharf, Leeds, West Yorkshire, LS11 5PS, UK
| | - Rachael E Tennant
- Lhasa Limited, Granary Wharf House, 2 Canal Wharf, Leeds, West Yorkshire, LS11 5PS, UK
| | - Robert F Thomas
- Lhasa Limited, Granary Wharf House, 2 Canal Wharf, Leeds, West Yorkshire, LS11 5PS, UK
| | - Kevin Cross
- Leadscope, Inc., an Instem Company, Columbus, OH, 43215, USA
| | - Andreas Czich
- Sanofi, R&D Preclinical Safety, D-65926, Frankfurt, Germany
| | - Kerstin Waese
- Sanofi, R&D Preclinical Safety, D-65926, Frankfurt, Germany
| | - John J Nicolette
- Janssen Pharmaceuticals, Global Toxicology, Raritan, New Jersey, USA
| | - Joel Murray
- AbbVie, Inc., Pre-clinical Safety, North Chicago, IL, USA
| | - Paul Sonders
- AbbVie, Inc., Pre-clinical Safety, North Chicago, IL, USA
| | | | - Jennifer R Cheung
- Pfizer Worldwide Research and Development, Genetic Toxicology, Eastern Point Road, Groton, CT, USA
| | - Dean Thomas
- GlaxoSmithKline R&D, Park Road, Ware, Hertfordshire, SG12 0DP, UK
| | - Anthony Lynch
- GlaxoSmithKline R&D, Park Road, Ware, Hertfordshire, SG12 0DP, UK
| | - James Harvey
- GlaxoSmithKline R&D, Park Road, Ware, Hertfordshire, SG12 0DP, UK
| | - Susanne Glowienke
- Novartis AG, NIBR, Pre-clinical Safety, WSJ-340, CH-4002 Basel, Switzerland
| | - Laura Custer
- Bristol-Myers Squibb, Nonclinical Safety, 1 Squibb Dr, New Brunswick, NJ, 08903, USA
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7
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Zeller A, Czich A, Guérard M, Honarvar N, Martus HJ, Pfuhler S, Vock E, Kirkland D. Letter to the editor. Mutat Res Genet Toxicol Environ Mutagen 2022; 876-877:503473. [PMID: 35483788 DOI: 10.1016/j.mrgentox.2022.503473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Affiliation(s)
- A Zeller
- F. Hoffmann-La Roche Ltd., Pharmaceutical Sciences, pRED Innovation Center Basel, 4070 Basel, Switzerland
| | - A Czich
- Sanofi, Research and Development, Industriepark Hoechst, 65926 Frankfurt, Germany
| | - M Guérard
- F. Hoffmann-La Roche Ltd., Pharmaceutical Sciences, pRED Innovation Center Basel, 4070 Basel, Switzerland
| | - N Honarvar
- BASF SE, Experimental Toxicology and Ecology, Z470, 67056 Ludwigshafen, Germany
| | - H-J Martus
- Novartis Institutes for BioMedical Research, 4057 Basel, Switzerland
| | - S Pfuhler
- Global Product Stewardship, The Procter & Gamble Company, Cincinnati, OH, USA
| | - E Vock
- Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Strasse 65, 88379 Biberach an der Riss, Germany
| | - D Kirkland
- Kirkland Consulting, PO Box 79, Tadcaster LS24 0AS, United Kingdom
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8
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Bercu JP, Masuda-Herrera M, Johnson G, Czich A, Glowienke S, Kenyon M, Thomas R, Ponting DJ, White A, Cross K, Waechter F, Rodrigues MAC. Use of less-than-lifetime (LTL) durational limits for nitrosamines: Case study of N-Nitrosodiethylamine (NDEA). Regul Toxicol Pharmacol 2021; 123:104926. [PMID: 33862169 DOI: 10.1016/j.yrtph.2021.104926] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 04/02/2021] [Accepted: 04/06/2021] [Indexed: 11/30/2022]
Abstract
The ICH M7(R1) guideline describes a framework to assess the carcinogenic risk of mutagenic and carcinogenic pharmaceutical impurities following less-than-lifetime (LTL) exposures. This LTL framework is important as many pharmaceuticals are not administered for a patient's lifetime and as clinical trials typically involve LTL exposures. While there has been regulatory caution about applying LTL concepts to cohort of concern (COC) impurities such as N-nitrosamines, ICH M7 does not preclude this and indeed literature data suggests that the LTL framework will be protective of patient safety for N-nitrosamines. The goal was to investigate if applying the LTL framework in ICH M7 would control exposure to an acceptable excess cancer risk in humans. Using N-nitrosodiethylamine as a case study, empirical data correlating exposure duration (as a percentage of lifespan) and cancer incidence in rodent bioassays indicate that the LTL acceptable intake (AI) as derived using the ICH M7 framework would not exceed a negligible additional risk of cancer. Therefore, controlling N-nitrosamines to an LTL AI based on the ICH M7 framework is thus demonstrated to be protective for potential carcinogenic risk to patients over the exposure durations typical of clinical trials and many prescribed medicines.
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Affiliation(s)
- Joel P Bercu
- Gilead Sciences, Nonclinical Safety and Pathobiology (NSP), Foster City, CA, USA.
| | | | - George Johnson
- Institute of Life Science, Swansea University Medical School, Singleton Park, Swansea, SA3 5DE, UK
| | - Andreas Czich
- Sanofi, R&D Preclinical Safety, D-65926, Frankfurt, Germany
| | | | - Michelle Kenyon
- Pfizer Worldwide Research and Development, Genetic Toxicology, Eastern Point Road, Groton, CT, USA
| | - Rob Thomas
- Lhasa Limited, Granary Wharf House, 2 Canal Wharf, Leeds, LS11 5PS, UK
| | - David J Ponting
- Lhasa Limited, Granary Wharf House, 2 Canal Wharf, Leeds, LS11 5PS, UK
| | - Angela White
- GlaxoSmithKline R&D, Park Road, Ware, Hertfordshire, SG12 0DP, UK
| | - Kevin Cross
- Leadscope Inc. an Instem Company, Columbus, OH, 43215, USA
| | - Fernanda Waechter
- Aché Laboratórios Farmacêuticos S.A., Rodovia Presidente Dutra, km 222,2, Porto da Igreja, 07034-904, Guarulhos, SP, Brazil
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9
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Schmidt F, Wenzel J, Halland N, Güssregen S, Delafoy L, Czich A. Computational Investigation of Drug Phototoxicity: Photosafety Assessment, Photo-Toxophore Identification, and Machine Learning. Chem Res Toxicol 2019; 32:2338-2352. [PMID: 31625387 DOI: 10.1021/acs.chemrestox.9b00338] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
One of the most appreciated capabilities of computational toxicology is to support the design of pharmaceuticals with reduced toxicological hazard. To this end, we have strengthened our drug photosafety assessments by applying novel computer models for the anticipation of in vitro phototoxicity and human photosensitization. These models are typically used in pharmaceutical discovery projects as part of the compound toxicity assessments and compound optimization methods. To ensure good data quality and aiming at models with global applicability we separately compiled and curated highly chemically diverse data sets from 3T3 NRU phototoxicity reports (450 compounds) and clinical photosensitization alerts (1419 compounds) which are provided as supplements. The latter data gives rise to a comprehensive list of explanatory fragments for visual guidance, termed phototoxophores, by application of a Bayesian statistics approach. To extend beyond the domain of well sampled fragments we applied machine learning techniques based on explanatory descriptors such as pharmacophoric fingerprints or, more important, accurate electronic energy descriptors. Electronic descriptors were extracted from quantum chemical computations at the density functional theory (DFT) level. Accurate UV/vis spectral absorption descriptors and pharmacophoric fingerprints turned out to be necessary for predictive computer models, which were both derived from Deep Neural Networks but also the simpler Random Decision Forests approach. Model accuracies of 83-85% could typically be reached for diverse test data sets and other company in-house data, while model sensitivity (the capability of correctly detecting toxicants) was even better, reaching 86%-90%. Importantly, a computer model-triggered response-map allowed for graphical/chemical interpretability also in the case of previously unknown phototoxophores. The photosafety models described here are currently applied in a prospective manner for the hazard identification, prioritization, and optimization of newly designed molecules.
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Affiliation(s)
| | - Jan Wenzel
- Sanofi R&D , Industriepark Hoechst , 65926 Frankfurt , Germany
| | - Nis Halland
- Sanofi R&D , Industriepark Hoechst , 65926 Frankfurt , Germany
| | | | | | - Andreas Czich
- Sanofi R&D , Industriepark Hoechst , 65926 Frankfurt , Germany
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10
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Beilmann M, Boonen H, Czich A, Dear G, Hewitt P, Mow T, Newham P, Oinonen T, Pognan F, Roth A, Valentin JP, Van Goethem F, Weaver RJ, Birk B, Boyer S, Caloni F, Chen AE, Corvi R, Cronin MTD, Daneshian M, Ewart LC, Fitzgerald RE, Hamilton GA, Hartung T, Kangas JD, Kramer NI, Leist M, Marx U, Polak S, Rovida C, Testai E, Van der Water B, Vulto P, Steger-Hartmann T. Optimizing drug discovery by Investigative Toxicology: Current and future trends. ALTEX 2018; 36:289-313. [PMID: 30570669 DOI: 10.14573/altex.1808181] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 12/20/2018] [Indexed: 11/23/2022]
Abstract
Investigative Toxicology describes the de-risking and mechanistic elucidation of toxicities, supporting early safety decisions in the pharmaceutical industry. Recently, Investigative Toxicology has contributed to a shift in pharmaceutical toxicology, from a descriptive to an evidence-based, mechanistic discipline. This was triggered by high costs and low throughput of Good Laboratory Practice in vivo studies, and increasing demands for adhering to the 3R (Replacement, Reduction and Refinement) principles of animal welfare. Outside the boundaries of regulatory toxicology, Investigative Toxicology has the flexibility to embrace new technologies, enhancing translational steps from in silico, in vitro to in vivo mechanistic understanding to eventually predict human response. One major goal of Investigative Toxicology is improving preclinical decisions, which coincides with the concept of animal-free safety testing. Currently, compounds under preclinical development are being discarded due to the use of inappropriate animal models. Progress in Investigative Toxicology could lead to humanized in vitro test systems and the development of medicines less reliant on animal tests. To advance this field a group of 14 European-based leaders from the pharmaceutical industry founded the Investigative Toxicology Leaders Forum (ITLF), an open, non-exclusive and pre-competitive group that shares knowledge and experience. The ITLF collaborated with the Centre for Alternatives to Animal Testing Europe (CAAT-Europe) to organize an "Investigative Toxicology Think-Tank", which aimed to enhance the interaction with experts from academia and regulatory bodies in the field. Summarizing the topics and discussion of the workshop, this article highlights Investigative Toxicology's position by identifying key challenges and perspectives.
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Affiliation(s)
- Mario Beilmann
- Nonclinical Drug Safety, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | | | | | - Gordon Dear
- Platform Technology & Science, David Jack Centre for R&D, GSK, Hertfordshire, UK
| | | | - Tomas Mow
- Global Discovery and Development Sciences, Novo Nordisk A/S, Maaloev, Denmark
| | - Peter Newham
- Drug Safety and Metabolism, Astra Zeneca, Cambridge, UK
| | - Teija Oinonen
- Investigative Toxicology and ADME, Orion Pharma, Espoo, Finland
| | | | - Adrian Roth
- Pharma Research and Early Development, Hoffmann-La Roche Ltd, Basel, Switzerland
| | | | - Freddy Van Goethem
- Mechanistic & Investigative Toxicology, Discovery Sciences, Janssen Research & Development, Beerse, Belgium
| | | | - Barbara Birk
- Experimental Toxicology and Ecology, BASF, Ludwigshafen, Germany
| | - Scott Boyer
- Computational Toxicology, Swedish Toxicological Sciences Research Center, Södertäljje, Sweden
| | - Francesca Caloni
- Department of Veterinary Medicine (DIMEVET), Università degli Studi di Milano, Milan, Italy
| | | | - Raffaella Corvi
- EURL-ECVAM, Joint Research Center, European Commission, Ispra (VA), Italy
| | - Mark T D Cronin
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, England
| | - Mardas Daneshian
- Center for Alternatives to Animal Testing (CAAT)-Europe, University of Konstanz, Konstanz, Germany
| | - Lorna C Ewart
- Drug Safety and Metabolism, Astra Zeneca, Cambridge, UK
| | - Rex E Fitzgerald
- Swiss Centre for Applied Human Toxicology, SCAHT / University of Basel, Basel, Switzerland
| | | | - Thomas Hartung
- Johns Hopkins University, CAAT, Baltimore, MD, USA.,Center for Alternatives to Animal Testing (CAAT)-Europe, University of Konstanz, Konstanz, Germany
| | - Joshua D Kangas
- Computational Biology Department, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Nynke I Kramer
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands
| | - Marcel Leist
- Center for Alternatives to Animal Testing (CAAT)-Europe, University of Konstanz, Konstanz, Germany
| | | | - Sebastian Polak
- Certara UK (Simcyp), Sheffield, United Kingdom.,Jagiellonian University Medical College, Kraków, Poland
| | - Costanza Rovida
- Center for Alternatives to Animal Testing (CAAT)-Europe, University of Konstanz, Konstanz, Germany
| | | | - Bob Van der Water
- Division of Drug Discovery and Safety, Leiden Academic Centre for Drug Research (LACDR), Leiden University, RA Leiden, The Netherlands
| | | | - Thomas Steger-Hartmann
- Research & Development, Pharmaceuticals, Investigational Toxicology, Bayer AG, Berlin, Germany
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Wenzel J, Anger L, Amberg A, Matter H, Hessler G, Griesang N, Mertsch K, Czich A, Schmidt F. Enhancing compound safety assessment using “Multitask” deep neural nets. Toxicol Lett 2018. [DOI: 10.1016/j.toxlet.2018.06.612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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12
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Zeller A, Pfuhler S, Albertini S, Bringezu F, Czich A, Dietz Y, Fautz R, Hewitt NJ, Kirst A, Kasper P. A critical appraisal of the sensitivity of in vivo genotoxicity assays in detecting human carcinogens. Mutagenesis 2018; 33:179-193. [DOI: 10.1093/mutage/gey005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 03/20/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Andreas Zeller
- Pharmaceutical Sciences, pRED Innovation Center Basel, F. Hoffmann-La Roche Ltd, Grenzacherstrasse, Basel, Switzerland
| | - Stefan Pfuhler
- Procter & Gamble, Global Product Stewardship, Human Safety, Mason Business Centre, Mason, OH, USA
| | - Silvio Albertini
- Pharmaceutical Sciences, pRED Innovation Center Basel, F. Hoffmann-La Roche Ltd, Grenzacherstrasse, Basel, Switzerland
| | | | - Andreas Czich
- Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, Frankfurt, Germany
| | - Yasmin Dietz
- Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, Frankfurt, Germany
| | | | | | | | - Peter Kasper
- Federal Institute for Drugs and Medical Devices (BfArM), Kurt-Georg-Kiesinger-Allee, Bonn, Germany
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13
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Teixidó E, Krupp E, Amberg A, Czich A, Scholz S. Species-specific developmental toxicity in rats and rabbits: Generation of a reference compound list for development of alternative testing approaches. Reprod Toxicol 2018; 76:93-102. [PMID: 29409988 DOI: 10.1016/j.reprotox.2018.01.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 12/05/2017] [Accepted: 01/26/2018] [Indexed: 11/19/2022]
Abstract
For regulatory information requirements, developmental toxicity testing is often conducted in two mammalian species. In order to provide a set of reference compounds that could be used to explore alternative approaches to supersede testing in a second species, a retrospective data analysis was conducted. The aim was to identify compounds for which species sensitivity differences between rats and rabbits are not caused by maternal toxicity or toxicokinetic differences. A total of 330 compounds were analysed and classified according to their species-specific differences. A lack of concordance between rat and rabbit was observed in 24% of the compounds, of which 10% were found to be selective developmental toxicants in one of the species. In contrast to previously published analyses the presented comparison is based entirely on publically data allowing validating and comparing alternative approaches for developmental toxicity testing. Furthermore, this list could be useful to identify mechanisms leading to species differences.
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Affiliation(s)
- E Teixidó
- Department of Bioanalytical Ecotoxicology, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318, Leipzig, Germany.
| | - E Krupp
- Sanofi-Aventis Deutschland GmbH, Preclinical Safety, Industriepark Hoechst, D-65926, Frankfurt am Main, Germany
| | - A Amberg
- Sanofi-Aventis Deutschland GmbH, Preclinical Safety, Industriepark Hoechst, D-65926, Frankfurt am Main, Germany
| | - A Czich
- Sanofi-Aventis Deutschland GmbH, Preclinical Safety, Industriepark Hoechst, D-65926, Frankfurt am Main, Germany
| | - S Scholz
- Department of Bioanalytical Ecotoxicology, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318, Leipzig, Germany
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14
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Schmidt F, Brennan R, Czich A. Mode-of-toxicity prediction for molecular design in the pharmaceutical industry. Toxicol Lett 2017. [DOI: 10.1016/j.toxlet.2017.07.176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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15
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Teixidó E, Leuthold D, Scholz S, Quevedo C, Muriana A, Czich A, Krupp E. An inter-laboratory validation of the zebrafish embryo assay for the detection of developmental toxicity. Reprod Toxicol 2016. [DOI: 10.1016/j.reprotox.2016.06.096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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16
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Richert L, Baze A, Parmentier C, Gerets HHJ, Sison-Young R, Dorau M, Lovatt C, Czich A, Goldring C, Park BK, Juhila S, Foster AJ, Williams DP. Cytotoxicity evaluation using cryopreserved primary human hepatocytes in various culture formats. Toxicol Lett 2016; 258:207-215. [PMID: 27363785 DOI: 10.1016/j.toxlet.2016.06.1127] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 06/23/2016] [Indexed: 11/25/2022]
Abstract
Sixteen training compounds selected in the IMI MIP-DILI consortium, 12 drug-induced liver injury (DILI) positive compounds and 4 non-DILI compounds, were assessed in cryopreserved primary human hepatocytes. When a ten-fold safety margin threshold was applied, the non-DILI-compounds were correctly identified 2h following a single exposure to pooled human hepatocytes (n=13 donors) in suspension and 14-days following repeat dose exposure (3 treatments) to an established 3D-microtissue co-culture (3D-MT co-culture, n=1 donor) consisting of human hepatocytes co-cultured with non-parenchymal cells (NPC). In contrast, only 5/12 DILI-compounds were correctly identified 2h following a single exposure to pooled human hepatocytes in suspension. Exposure of the 2D-sandwich culture human hepatocyte monocultures (2D-sw) for 3days resulted in the correct identification of 11/12 DILI-positive compounds, whereas exposure of the human 3D-MT co-cultures for 14days resulted in identification of 9/12 DILI-compounds; in addition to ximelagatran (also not identified by 2D-sw monocultures, Sison-Young et al., 2016), the 3D-MT co-cultures failed to detect amiodarone and bosentan. The sensitivity of the 2D human hepatocytes co-cultured with NPC to ximelagatran was increased in the presence of lipopolysaccharide (LPS), but only at high concentrations, therefore preventing its classification as a DILI positive compound. In conclusion (1) despite suspension human hepatocytes having the greatest metabolic capacity in the short term, they are the least predictive of clinical DILI across the MIP-DILI test compounds, (2) longer exposure periods than 72h of human hepatocytes do not allow to increase DILI-prediction rate, (3) co-cultures of human hepatocytes with NPC, in the presence of LPS during the 72h exposure period allow the assessment of innate immune system involvement of a given drug.
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Affiliation(s)
- Lysiane Richert
- KaLy-Cell, 20A rue du Général Leclerc, 67115 Plobsheim, France; Université de Franche-Comté, EA 4267 Besançon, France.
| | - Audrey Baze
- KaLy-Cell, 20A rue du Général Leclerc, 67115 Plobsheim, France.
| | | | - Helga H J Gerets
- UCB BioPharma SPRL, Non-Clinical Development, Chemin du Foriest, 1420 Braine-l'Alleud, Belgium.
| | - Rowena Sison-Young
- MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, Sherrington Building, Ashton Street, University of Liverpool, Liverpool L69 3GE, UK.
| | - Martina Dorau
- Sanofi-Aventis Deutschland GmbH, R&D DSAR Preclinical Safety, Industriepark Hoechst, D-65926 Frankfurt, Germany.
| | - Cerys Lovatt
- GlaxoSmithKline, Safety Assessment, Stevenage, Hertfordshire, UK.
| | - Andreas Czich
- Sanofi-Aventis Deutschland GmbH, R&D DSAR Preclinical Safety, Industriepark Hoechst, D-65926 Frankfurt, Germany.
| | - Christopher Goldring
- MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, Sherrington Building, Ashton Street, University of Liverpool, Liverpool L69 3GE, UK.
| | - B Kevin Park
- MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, Sherrington Building, Ashton Street, University of Liverpool, Liverpool L69 3GE, UK.
| | - Satu Juhila
- Orion Corporation, R&D, In Vitro Biology, Orionintie 1A, P.O. Box 65, FI-02101 Espoo, Finland.
| | - Alison J Foster
- Translational Safety, Drug Safety & Metabolism, AstraZeneca, Cambridge Science Park, Cambridge, UK.
| | - Dominic P Williams
- Translational Safety, Drug Safety & Metabolism, AstraZeneca, Cambridge Science Park, Cambridge, UK.
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17
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Abstract
Hepatic toxicity is a key concern for novel pharmaceutical drugs since it is difficult to anticipate in preclinical models, and it can originate from pharmacologically unrelated drug effects, such as pathway interference, metabolism, and drug accumulation. Because liver toxicity still ranks among the top reasons for drug attrition, the reliable prediction of adverse hepatic effects is a substantial challenge in drug discovery and development. To this end, more effort needs to be focused on the development of improved predictive in-vitro and in-silico approaches. Current computational models often lack applicability to novel pharmaceutical candidates, typically due to insufficient coverage of the chemical space of interest, which is either imposed by size or diversity of the training data. Hence, there is an urgent need for better computational models to allow for the identification of safe drug candidates and to support experimental design. In this context, a large data set comprising 3712 compounds with liver related toxicity findings in humans and animals was collected from various sources. The complex pathology was clustered into 21 preclinical and human hepatotoxicity endpoints, which were organized into three levels of detail. Support vector machine models were trained for each endpoint, using optimized descriptor sets from chemometrics software. The optimized global human hepatotoxicity model has high sensitivity (68%) and excellent specificity (95%) in an internal validation set of 221 compounds. Models for preclinical endpoints performed similarly. To allow for reliable prediction of "truly external" novel compounds, all predictions are tagged with confidence parameters. These parameters are derived from a statistical analysis of the predictive probability densities. The whole approach was validated for an external validation set of 269 proprietary compounds. The models are fully integrated into our early safety in-silico workflow.
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Affiliation(s)
- Denis Mulliner
- R&D DSAR/Preclinical Safety FF, Sanofi-Aventis Deutschland GmbH , Industriepark Hoechst, Building H831, D-65926 Frankfurt am Main, Germany
| | - Friedemann Schmidt
- R&D DSAR/Preclinical Safety FF, Sanofi-Aventis Deutschland GmbH , Industriepark Hoechst, Building H831, D-65926 Frankfurt am Main, Germany
| | - Manuela Stolte
- R&D DSAR/Preclinical Safety FF, Sanofi-Aventis Deutschland GmbH , Industriepark Hoechst, Building H831, D-65926 Frankfurt am Main, Germany
| | - Hans-Peter Spirkl
- R&D DSAR/Preclinical Safety FF, Sanofi-Aventis Deutschland GmbH , Industriepark Hoechst, Building H831, D-65926 Frankfurt am Main, Germany
| | - Andreas Czich
- R&D DSAR/Preclinical Safety FF, Sanofi-Aventis Deutschland GmbH , Industriepark Hoechst, Building H831, D-65926 Frankfurt am Main, Germany
| | - Alexander Amberg
- R&D DSAR/Preclinical Safety FF, Sanofi-Aventis Deutschland GmbH , Industriepark Hoechst, Building H831, D-65926 Frankfurt am Main, Germany
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18
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Mulliner D, Schmidt F, Stolte M, Spirkl HP, Czich A, Amberg A. Computational Models for Human and Animal Hepatotoxicity with a Global Application Scope. Chem Res Toxicol 2016; 29:757-67. [PMID: 26914516 DOI: 10.1021/acs.chemrestox.5b00465] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Hepatic toxicity is a key concern for novel pharmaceutical drugs since it is difficult to anticipate in preclinical models, and it can originate from pharmacologically unrelated drug effects, such as pathway interference, metabolism, and drug accumulation. Because liver toxicity still ranks among the top reasons for drug attrition, the reliable prediction of adverse hepatic effects is a substantial challenge in drug discovery and development. To this end, more effort needs to be focused on the development of improved predictive in-vitro and in-silico approaches. Current computational models often lack applicability to novel pharmaceutical candidates, typically due to insufficient coverage of the chemical space of interest, which is either imposed by size or diversity of the training data. Hence, there is an urgent need for better computational models to allow for the identification of safe drug candidates and to support experimental design. In this context, a large data set comprising 3712 compounds with liver related toxicity findings in humans and animals was collected from various sources. The complex pathology was clustered into 21 preclinical and human hepatotoxicity endpoints, which were organized into three levels of detail. Support vector machine models were trained for each endpoint, using optimized descriptor sets from chemometrics software. The optimized global human hepatotoxicity model has high sensitivity (68%) and excellent specificity (95%) in an internal validation set of 221 compounds. Models for preclinical endpoints performed similarly. To allow for reliable prediction of "truly external" novel compounds, all predictions are tagged with confidence parameters. These parameters are derived from a statistical analysis of the predictive probability densities. The whole approach was validated for an external validation set of 269 proprietary compounds. The models are fully integrated into our early safety in-silico workflow.
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Affiliation(s)
- Denis Mulliner
- R&D DSAR/Preclinical Safety FF, Sanofi-Aventis Deutschland GmbH , Industriepark Hoechst, Building H831, D-65926 Frankfurt am Main, Germany
| | - Friedemann Schmidt
- R&D DSAR/Preclinical Safety FF, Sanofi-Aventis Deutschland GmbH , Industriepark Hoechst, Building H831, D-65926 Frankfurt am Main, Germany
| | - Manuela Stolte
- R&D DSAR/Preclinical Safety FF, Sanofi-Aventis Deutschland GmbH , Industriepark Hoechst, Building H831, D-65926 Frankfurt am Main, Germany
| | - Hans-Peter Spirkl
- R&D DSAR/Preclinical Safety FF, Sanofi-Aventis Deutschland GmbH , Industriepark Hoechst, Building H831, D-65926 Frankfurt am Main, Germany
| | - Andreas Czich
- R&D DSAR/Preclinical Safety FF, Sanofi-Aventis Deutschland GmbH , Industriepark Hoechst, Building H831, D-65926 Frankfurt am Main, Germany
| | - Alexander Amberg
- R&D DSAR/Preclinical Safety FF, Sanofi-Aventis Deutschland GmbH , Industriepark Hoechst, Building H831, D-65926 Frankfurt am Main, Germany
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Amberg A, Harvey JS, Czich A, Spirkl HP, Robinson S, White A, Elder DP. Do Carboxylic/Sulfonic Acid Halides Really Present a Mutagenic and Carcinogenic Risk as Impurities in Final Drug Products? Org Process Res Dev 2015. [DOI: 10.1021/acs.oprd.5b00106] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alexander Amberg
- Sanofi-Aventis Deutschland GmbH, R&D DSAR/Preclinical Safety FF, Industriepark Hoechst, Building H831, D-65926 Frankfurt, Germany
| | - James S. Harvey
- GlaxoSmithKline Pre-Clinical Development, Park Road, Ware, Hertfordshire SG12 0DP, U.K
| | - Andreas Czich
- Sanofi-Aventis Deutschland GmbH, R&D DSAR/Preclinical Safety FF, Industriepark Hoechst, Building H831, D-65926 Frankfurt, Germany
| | - Hans-Peter Spirkl
- Sanofi-Aventis Deutschland GmbH, R&D DSAR/Preclinical Safety FF, Industriepark Hoechst, Building H831, D-65926 Frankfurt, Germany
| | - Sharon Robinson
- GlaxoSmithKline Pre-Clinical Development, Park Road, Ware, Hertfordshire SG12 0DP, U.K
| | - Angela White
- GlaxoSmithKline Pre-Clinical Development, Park Road, Ware, Hertfordshire SG12 0DP, U.K
| | - David P. Elder
- GlaxoSmithKline Pre-Clinical Development, Park Road, Ware, Hertfordshire SG12 0DP, U.K
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Schmidt F, Amberg A, Mulliner D, Stolte M, Matter H, Hessler G, Dietrich A, Remez N, Vidal D, Mestres J, Czich A. Computational prediction of off-target related safety liabilities of molecules: Cardiotoxicity, hepatotoxicity and reproductive toxicity. Toxicol Lett 2014. [DOI: 10.1016/j.toxlet.2014.06.564] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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21
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Krupp E, Czich A. Leveraging early pharmacology studies and animal models of human disease to learn about toxicity. Toxicol Lett 2013. [DOI: 10.1016/j.toxlet.2013.06.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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22
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Dearfield KL, Thybaud V, Cimino MC, Custer L, Czich A, Harvey JS, Hester S, Kim JH, Kirkland D, Levy DD, Lorge E, Moore MM, Ouédraogo-Arras G, Schuler M, Suter W, Sweder K, Tarlo K, van Benthem J, van Goethem F, Witt KL. Follow-up actions from positive results of in vitro genetic toxicity testing. Environ Mol Mutagen 2011; 52:177-204. [PMID: 20963811 DOI: 10.1002/em.20617] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Revised: 06/16/2010] [Accepted: 06/18/2010] [Indexed: 05/30/2023]
Abstract
Appropriate follow-up actions and decisions are needed when evaluating and interpreting clear positive results obtained in the in vitro assays used in the initial genotoxicity screening battery (i.e., the battery of tests generally required by regulatory authorities) to assist in overall risk-based decision making concerning the potential effects of human exposure to the agent under test. Over the past few years, the International Life Sciences Institute (ILSI) Health and Environmental Sciences Institute (HESI) Project Committee on the Relevance and Follow-up of Positive Results in In Vitro Genetic Toxicity (IVGT) Testing developed a decision process flow chart to be applied in case of clear positive results in vitro. It provides for a variety of different possibilities and allows flexibility in choosing follow-up action(s), depending on the results obtained in the initial battery of assays and available information. The intent of the Review Subgroup was not to provide a prescriptive testing strategy, but rather to reinforce the concept of weighing the totality of the evidence. The Review Subgroup of the IVGT committee highlighted the importance of properly analyzing the existing data, and considering potential confounding factors (e.g., possible interactions with the test systems, presence of impurities, irrelevant metabolism), and chemical modes of action when analyzing and interpreting positive results in the in vitro genotoxicity assays and determining appropriate follow-up testing. The Review Subgroup also examined the characteristics, strengths, and limitations of each of the existing in vitro and in vivo genotoxicity assays to determine their usefulness in any follow-up testing.
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Affiliation(s)
- Kerry L Dearfield
- U.S. Department of Agriculture, Food Safety and Inspection Service, Washington, District of Columbia, USA
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Rothfuss A, O'Donovan M, De Boeck M, Brault D, Czich A, Custer L, Hamada S, Plappert-Helbig U, Hayashi M, Howe J, Kraynak AR, van der Leede BJ, Nakajima M, Priestley C, Thybaud V, Saigo K, Sawant S, Shi J, Storer R, Struwe M, Vock E, Galloway S. Collaborative study on fifteen compounds in the rat-liver Comet assay integrated into 2- and 4-week repeat-dose studies. Mutat Res 2010; 702:40-69. [PMID: 20656055 DOI: 10.1016/j.mrgentox.2010.07.006] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Revised: 06/14/2010] [Accepted: 06/24/2010] [Indexed: 11/28/2022]
Abstract
A collaborative trial was conducted to evaluate the possibility of integrating the rat-liver Comet assay into repeat-dose toxicity studies. Fourteen laboratories from Europe, Japan and the USA tested fifteen chemicals. Two chemicals had been previously shown to induce micronuclei in an acute protocol, but were found negative in a 4-week Micronucleus (MN) Assay (benzo[a]pyrene and 1,2-dimethylhydrazine; Hamada et al., 2001); four genotoxic rat-liver carcinogens that were negative in the MN assay in bone marrow or blood (2,6-dinitrotoluene, dimethylnitrosamine, 1,2-dibromomethane, and 2-amino-3-methylimidazo[4,5-f]quinoline); three compounds used in the ongoing JaCVAM (Japanese Center for the Validation of Alternative Methods) validation study of the acute liver Comet assay (2,4-diaminotoluene, 2,6-diaminotoluene and acrylamide); three pharmaceutical-like compounds (chlordiazepoxide, pyrimethamine and gemifloxacin), and three non-genotoxic rodent liver carcinogens (methapyrilene, clofibrate and phenobarbital). Male rats received oral administrations of the test compounds, daily for two or four weeks. The top dose was meant to be the highest dose producing clinical signs or histopathological effects without causing mortality, i.e. the 28-day maximum tolerated dose. The liver Comet assay was performed according to published recommendations and following the protocol for the ongoing JaCVAM validation trial. Laboratories provided liver Comet assay data obtained at the end of the long-term (2- or 4-week) studies together with an evaluation of liver histology. Most of the test compounds were also investigated in the liver Comet assay after short-term (1-3 daily) administration to compare the sensitivity of the two study designs. MN analyses were conducted in bone marrow or peripheral blood for most of the compounds to determine whether the liver Comet assay could complement the MN assay for the detection of genotoxins after long-term treatment. Most of the liver genotoxins were positive and the three non-genotoxic carcinogens gave negative result in the liver Comet assay after long-term administration. There was a high concordance between short- and long-term Comet assay results. Most compounds when tested up to the maximum tolerated dose were correctly detected in both short- and long-term studies. Discrepant results were obtained with 2,6 diaminotoluene (negative in the short-term, but positive in the long-term study), phenobarbital (positive in the short-term, but negative in the long-term study) and gemifloxacin (positive in the short-term, but negative in the long-term study). The overall results indicate that the liver Comet assay can be integrated within repeat-dose toxicity studies and efficiently complements the MN assay in detecting genotoxins. Practical aspects of integrating genotoxicity endpoints into repeat-dose studies were evaluated, e.g. by investigating the effect of blood sampling, as typically performed during toxicity studies, on the Comet and MN assays. The bleeding protocols used here did not affect the conclusions of the Comet assay or of the MN assays in blood and bone marrow. Although bleeding generally increased reticulocyte frequencies, the sensitivity of the response in the MN assay was not altered. These findings indicate that all animals in a toxicity study (main-study animals as well as toxicokinetic (TK) satellite animals) could be used for evaluating genotoxicity. However, possible logistical issues with scheduling of the necropsies and the need to conduct electrophoresis promptly after tissue sampling suggest that the use of TK animals could be simpler. The data so far do not indicate that liver proliferation or toxicity confound the results of the liver Comet assay. As was also true for other genotoxicity assays, criteria for evaluation of Comet assay results and statistical analyses differed among laboratories. Whereas comprehensive advice on statistical analysis is available in the literature, agreement is needed on applying consistent criteria.
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Affiliation(s)
- Andreas Rothfuss
- Bayer Schering Pharma AG, Nonclinical Drug Safety, Berlin, Germany.
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Brendler-Schwaab S, Czich A, Epe B, Gocke E, Kaina B, Müller L, Pollet D, Utesch D. Photochemical genotoxicity: principles and test methods. Report of a GUM task force. Mutat Res 2004; 566:65-91. [PMID: 14706512 DOI: 10.1016/s1383-5742(03)00052-8] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
In recent years, assessing the photogenotoxic potential of a compound became an issue for certain drugs and cosmetical products. Therefore, existing methods performed according to international guidelines (e.g. OECD guidelines) were adapted to the use of concurrent UV-visible (UV-Vis) light irradiation for the assessment of photomutagenicity/photogenotoxicity. In this review, photobiological bases of the processes occurring in the cell after irradiation with UV- and/or visible (vis)-light as well as a compilation of testing methods is presented. Methods comprise cell free investigations on naked DNA and in vitro methods, such as the photo-Ames test, the photo-HPRT/photo-mouse lymphoma assay (MLA), the photo-micronucleus test (MNT), the photo-chromosomal aberration test (CA) and the photo-Comet assay. A compilation of the currently available international literature of compounds tested on photogenotoxicity is given for each method. The state of the art of photogenotoxicity testing as well as the rational for testing are outlined in relation to the recommendations reached in expert working groups at different international meetings and to regulatory guidance papers. Finally, photogenotoxicity testing as predictor of photocarcinogenicity and in the light of risk assessment is discussed.
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Abstract
Rat and human sulfotransferases (STs) were expressed in his- S. typhimurium strains. These new bacterial strains detected various mutagens which are difficult to recognize in traditional test systems, including benzylic alcohols derived from polycyclic aromatic hydrocarbons, hycanthone and 1'-hydroxysafrole. STs were also stably expressed in V79 Chinese hamster cells, which do not express endogenous ST and are suitable for the detection of genotoxic effects. Positive responses in these test systems were observed with various benzylic alcohols, including benzo[a]pyrene-7,8,9,10-tetrols. We demonstrate that a few reactive sulfuric acid conjugates are efficiently detected as genotoxicants only when generated directly within the indicator cell.
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Affiliation(s)
- H Glatt
- Deutsches Institut für Ernährungsforschung, Potsdam, Germany
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Glatt H, Pauly K, Czich A, Falany JL, Falany CN. Activation of benzylic alcohols to mutagens by rat and human sulfotransferases expressed in Escherichia coli. Eur J Pharmacol 1995; 293:173-81. [PMID: 7589232 DOI: 10.1016/0926-6917(95)90002-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Human hydroxysteroid sulfotransferase, human phenol-sulfating form of phenol sulfotransferase, rat hydroxysteroid sulfotransferase a and rat phenol sulfotransferase IV were expressed in Escherichia coli. Cytosol preparations of transformed bacteria were used as activating systems in mutagenicity tests with Salmonella typhimurium TA98. All test compounds, 1-hydroxymethylpyrene, 2-hydroxymethylpyrene, 1-(1-pyrenyl)ethanol, 9-hydroxymethylanthracene, 7-hydroxymethyl-12-methylbenz[a]anthracene and 4H-cyclopenta[def]chrysen-4-ol, were activated by both hydroxysteroid sulfotransferases investigated. However, 1-(1-pyrenyl)ethanol was 67-fold more efficiently activated by the human enzyme, whereas 7-hydroxymethyl-12-methylbenz[a]anthracene was 27-fold more efficiently activated by the rat enzyme. The phenol sulfotransferases showed relatively low activities with the benzylic alcohols investigated. The only exception was 4H-cyclopenta[def]chrysen-4-ol, which was activated efficiently by rat phenol sulfotransferase IV. We had previously tested the ability of rat and human hepatic cytosol preparations to activate the same compounds. The results of a statistical analysis suggest that the activities of human hydroxysteroid sulfotransferase, rat hydroxysteroid sulfotransferase a and phenol sulfotransferase IV can account for a substantial portion of the activation of benzylic alcohols in human, female rat and male rat liver, respectively.
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Affiliation(s)
- H Glatt
- Deutsches Institut für Ernährungsforschung, Potsdam-Rehbrücke, Germany
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Glatt H, Pudil J, Seidel A, Czich A. Stable Expression of Heterologous Sulfotransferase in V79 Cells: Activation of Primary and Secondary Benzylic Alcohols. Polycycl Aromat Compd 1994. [DOI: 10.1080/10406639408014714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Czich A, Bartsch I, Dogra S, Hornhardt S, Glatt HR. Stable heterologous expression of hydroxysteroid sulphotransferase in Chinese hamster V79 cells and their use for toxicological investigations. Chem Biol Interact 1994; 92:119-28. [PMID: 8033247 DOI: 10.1016/0009-2797(94)90058-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Various benzylic alcohols are metabolically activated to electrophilic, potentially mutagenic and carcinogenic sulphuric acid esters. The involved sulphotransferases are not expressed in the cell lines in culture which are commonly used for mutagenicity testing. The liver of adult female rats is very efficient in the bioactivation of 1-hydroxymethylpyrene. The major enzyme involved was purified and identified as hydroxysteroid sulphotransferase a. Its cDNA was stably expressed in Chinese hamster V79 cells, which are particularly suited for the quantitative detection of various types of mutations and other genotoxic and cytotoxic effects. The mRNA, protein and enzyme activity levels in the constructed cell lines (V79rSTa-1 and V79rSTa-2) were measured, and the cells were also used in mutagenicity and cytotoxicity investigations with benzylic alcohols. 1-Hydroxymethylpyrene, 9-hydroxymethylanthracene and 6-hydroxymethylbenzo[a]pyrene showed enhanced cytotoxicity in V79rSTa-1 and V79rSTa-2 cells, as compared with sulphotransferase-deficient control cells. In addition, 1-hydroxymethylpyrene induced sister chromatid exchanges, and 6-hydroxymethylbenzo[a]pyrene induced gene mutations in V79rSTa-1 cells. We intend carrying out more investigations with other chemicals on these cell lines. Their advantages, as compared with systems with external metabolising systems, include the formation of the active metabolites within the target cell, as in ST-proficient cells in vivo, eliminating the problems which may result from restricted intercellular transport of reactive and ionized sulphuric acid conjugates. Furthermore, cells expressing other sulphotransferases, including human enzymes, may be constructed and used for comparative investigations.
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Affiliation(s)
- A Czich
- Department of Toxicology, Deutsches Institute für Ernähtungsforschung, Potsdam-Rehbrücke, Germany
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Glatt H, Pauly K, Piée-Staffa A, Seidel A, Hornhardt S, Czich A. Activation of promutagens by endogenous and heterologous sulfotransferases expressed in continuous cell cultures. Toxicol Lett 1994; 72:13-21. [PMID: 8202924 DOI: 10.1016/0378-4274(94)90005-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Various environmental chemicals are metabolised to chemically reactive sulfuric acid esters, which may covalently bind to cellular macromolecules and induce mutations and tumours. This activation pathway is usually not taken into account in external xenobiotic-metabolising systems used in short-term tests. We therefore analysed the abilities of cytosols from mammalian cell lines to activate benzylic alcohols (1-hydroxymethylpyrene and 9-hydroxymethylanthracene) to mutagens detectable in Salmonella typhimurium TA98. No activation was observed in cell lines which are commonly used in mutagenicity and cell transformation assays, and only low activities were found in epithelial cell lines in culture. We have therefore constructed Chinese hamster V79-derived cell lines which stably express a heterologous sulfotransferase, rat hydroxysteroid sulfotransferase a. Cytosol of these cells effectively activated 1-hydroxymethylpyrene and 9-hydroxymethylanthracene to mutagens detected in S. typhimurium. The hepatocarcinogen 6-hydroxymethylbenzo[a]pyrene induced gene mutations in sulfotransferase-expressing V79-derived cells, whereas it elicited only marginal effects in sulfotransferase-deficient control cells. The new cell lines may allow the detection of novel classes of mutagens, since some externally generated reactive sulfuric acid esters may not readily penetrate target cells due to their short life span and their ionization.
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Affiliation(s)
- H Glatt
- Department of Toxicology, University of Mainz, Germany
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Glatt H, Werle-Schneider G, Enders N, Monnerjahn S, Pudil J, Czich A, Seidel A, Schwarz M. 1-Hydroxymethylpyrene and its sulfuric acid ester: toxicological effects in vitro and in vivo, and metabolic aspects. Chem Biol Interact 1994; 92:305-19. [PMID: 8033264 DOI: 10.1016/0009-2797(94)90072-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
1-Hydroxymethylpyrene (HMP) is activated to a potent mutagen, detectable in Salmonella typhimurium, in the presence of hepatic cytosol, cofactor for sulfotransferases, and chloride anions. The number of induced mutations is linear to the amount of cytosol used over a wide range, allowing for the quantification of this activity. The activity is expressed with high selectivity in certain tissues and cell types. In adult rats, the highest level is found in the liver, the activity in females exceeding that in males about threefold. About half of the activity in the liver of females is provided by hydroxysteroid sulfotransferase a (STa), whereas other enzymes may be more important in males on account of their very low level of STa. The expression of STa is decreased in ATPase-negative, presumably preneoplastic, hepatic foci in female rats. In contrast to its high mutagenicity in bacteria, SMP shows only weak mutagenic activity in mammalian cells (Chinese hamster V79 cells), independently of whether it is externally added, or generated from HMP within the cells by heterologously expressed STa. Sulfation, however, strongly enhances the cytotoxicity of HMP in mammalian cells. The high cytotoxicity and low mutagenicity in mammalian cells in culture have possible correlates in vivo: while HMP is only a weak initiator of ATPase-negative hepatic foci in newborn rats, it shows substantial promoting activity with regard to such foci in female, but not in male rats. We postulate that this promotion results from selective toxification by STa in the normal hepatic parenchyma of female rats, and resistance of ATPase/STa-negative foci.
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Affiliation(s)
- H Glatt
- Department of Toxicology, German Institute of Human Nutrition, Potsdam-Rehbrücke
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