1
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Hosoi S, Hirose T, Matsumura S, Otsubo Y, Saito K, Miyazawa M, Suzuki T, Masumura K, Sugiyama KI. Effect of sequencing platforms on the sensitivity of chemical mutation detection using Hawk-Seq™. Genes Environ 2024; 46:20. [PMID: 39385252 PMCID: PMC11462924 DOI: 10.1186/s41021-024-00313-9] [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: 06/07/2024] [Accepted: 09/22/2024] [Indexed: 10/12/2024] Open
Abstract
BACKGROUND Error-corrected next-generation sequencing (ecNGS) technologies have enabled the direct evaluation of genome-wide mutations after exposure to mutagens. Previously, we reported an ecNGS methodology, Hawk-Seq™, and demonstrated its utility in evaluating mutagenicity. The evaluation of technical transferability is essential to further evaluate the reliability of ecNGS-based assays. However, cutting-edge sequencing platforms are continually evolving, which can affect the sensitivity of ecNGS. Therefore, the effect of differences in sequencing instruments on mutation data quality should be evaluated. RESULTS We assessed the performance of four sequencing platforms (HiSeq2500, NovaSeq6000, NextSeq2000, and DNBSEQ-G400) with the Hawk-Seq™ protocol for mutagenicity evaluation using DNA samples from mouse bone marrow exposed to benzo[a]pyrene (BP). The overall mutation (OM) frequencies per 106 bp in vehicle-treated samples were 0.22, 0.36, 0.46, and 0.26 for HiSeq2500, NovaSeq6000, NextSeq2000, and DNBSEQ-G400, respectively. The OM frequency of NextSeq2000 was significantly higher than that of HiSeq2500, suggesting the difference to be based on the platform. The relatively higher value in NextSeq2000 was a consequence of the G:C to C:G mutations in NextSeq2000 data (0.67 per 106 G:C bp), which was higher than the mean of the four platforms by a ca. of 0.25 per 106 G:C bp. A clear dose-dependent increase in G:C to T:A mutation frequencies was observed in all four sequencing platforms after BP exposure. The cosine similarity values of the 96-dimensional trinucleotide mutation patterns between HiSeq and the three other platforms were 0.93, 0.95, and 0.92 for NovaSeq, NextSeq, and DNBSeq, respectively. These results suggest that all platforms can provide equivalent data that reflect the characteristics of the mutagens. CONCLUSIONS All platforms sensitively detected mutagen-induced mutations using the Hawk-Seq™ analysis. The substitution types and frequencies of the background errors differed depending on the platform. The effects of sequencing platforms on mutagenicity evaluation should be assessed before experimentation.
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Affiliation(s)
- Sayaka Hosoi
- R&D - Safety Science Research, Kao Corporation, 3-25-14 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa, 210-0821, Japan
| | - Takako Hirose
- R&D - Safety Science Research, Kao Corporation, 3-25-14 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa, 210-0821, Japan
| | - Shoji Matsumura
- R&D - Safety Science Research, Kao Corporation, 3-25-14 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa, 210-0821, Japan.
| | - Yuki Otsubo
- R&D - Safety Science Research, Kao Corporation, 3-25-14 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa, 210-0821, Japan
| | - Kazutoshi Saito
- R&D - Safety Science Research, Kao Corporation, 2606 Akabane, Ichikai-Machi, Haga-Gun, Tochigi, 321-3497, Japan
| | - Masaaki Miyazawa
- R&D - Safety Science Research, Kao Corporation, 2606 Akabane, Ichikai-Machi, Haga-Gun, Tochigi, 321-3497, Japan
| | - Takayoshi Suzuki
- Division of Genome Safety Science, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa, 210-9501, Japan
| | - Kenichi Masumura
- Division of Risk Assessment, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa, 210-9501, Japan
| | - Kei-Ichi Sugiyama
- Division of Genome Safety Science, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa, 210-9501, Japan
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2
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Esina E, Dodge AE, Williams A, Schuster DM, LeBlanc DPM, Marchetti F, Yauk CL. Power analyses to inform Duplex Sequencing study designs for MutaMouse liver and bone marrow. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2024. [PMID: 39267335 DOI: 10.1002/em.22619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2024] [Revised: 07/26/2024] [Accepted: 08/06/2024] [Indexed: 09/17/2024]
Abstract
Regulatory genetic toxicology testing is essential for identifying potentially mutagenic hazards. Duplex Sequencing (DS) is an error-corrected next-generation sequencing technology that provides substantial advantages for mutation analysis over conventional mutagenicity assays including: improved accuracy of mutation detection, ability to measure changes in mutation spectrum, and applicability across diverse biological models. To apply DS for regulatory toxicology testing, power analyses are required to determine suitable sample sizes and study designs. In this study, we explored study designs to achieve sufficient power for various effect sizes in chemical mutagenicity assessment. We collected data from MutaMouse bone marrow and liver samples that were analyzed by DS using TwinStrand's Mouse Mutagenesis Panel. Average duplex reads achieved in two separates studies on liver and bone marrow were 8.4 × 108 (± 7.4 × 107) and 9.5 × 108 (± 1.0 × 108), respectively. Baseline mean mutation frequencies (MF) were 4.6 × 10-8 (± 6.7 × 10-9) and 4.6 × 10-8 (± 1.1 × 10-8), with estimated standard deviations for the animal-to-animal random effect of 0.15 and 0.20, for liver and bone marrow, respectively. We conducted simulation analyses based on these empirically derived parameters. We found that a sample size of four animals per group is sufficient to obtain over 80% power to detect a two-fold change in MF relative to baseline. In addition, we estimated the minimal total number of informative duplex bases sequenced with different sample sizes required to retain power for various effect sizes. Our work provides foundational data for establishing suitable study designs for mutagenicity testing using DS.
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Affiliation(s)
- Elena Esina
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Annette E Dodge
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Andrew Williams
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - David M Schuster
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Danielle P M LeBlanc
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Francesco Marchetti
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Carole L Yauk
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
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3
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Zhang S, Coffing SL, Gunther WC, Homiski ML, Spellman RA, Van P, Schuler M. Assessing the genotoxicity of N-nitrosodiethylamine with three in vivo endpoints in male Big Blue® transgenic and wild-type C57BL/6N mice. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2024. [PMID: 39012003 DOI: 10.1002/em.22615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 06/11/2024] [Accepted: 06/14/2024] [Indexed: 07/17/2024]
Abstract
The detection of N-nitrosamines in drug products has raised global regulatory interest in recent years due to the carcinogenic potential of some nitrosamines in animals and a need to identify a testing strategy has emerged. Ideally, methods used would allow for the use of quantitative analysis of dose-response data from in vivo genotoxicity assays to determine a compound-specific acceptable intake for novel nitrosamines without sufficient carcinogenicity data. In a previous study we compared the dose-response relationships of N-nitrosodiethylamine (NDEA) in three in vivo genotoxicity endpoints in rats. Here we report a comparison of NDEA's genotoxicity profile in mice. Big Blue® mice were administered NDEA at doses of 0.001, 0.01, 0.1, 1 and 3 mg/kg/day by oral gavage for 28 days followed by 3 days of expression. Statistically significant increases in the NDEA induced mutations were detected by both the transgenic rodent mutation assay (TGR) using the cII endpoint and by duplex sequencing in the liver but not bone marrow of mice. In addition, administration of NDEA for two consecutive days in male C57BL/6N mice caused elevated DNA damage levels in the liver as measured by % tail DNA in comet assay. The benchmark dose (BMD) analysis shows a BMDL50 of 0.03, 0.04 and 0.72 mg/kg/day for TGR, duplex sequencing and comet endpoints, respectively. Overall, this study demonstrated a similar genotoxicity profile of NDEA between mice and rats and provides a reference that can be used to compare the potential potency of other novel nitrosamines for the induction of gene mutations.
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Affiliation(s)
- Shaofei Zhang
- Pfizer Research, Development, and Medical, Groton, Connecticut, USA
| | | | | | | | | | - Phu Van
- TwinStrand Biosciences, Inc., Seattle, Washington, USA
| | - Maik Schuler
- Pfizer Research, Development, and Medical, Groton, Connecticut, USA
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4
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Johnson MTJ, Arif I, Marchetti F, Munshi-South J, Ness RW, Szulkin M, Verrelli BC, Yauk CL, Anstett DN, Booth W, Caizergues AE, Carlen EJ, Dant A, González J, Lagos CG, Oman M, Phifer-Rixey M, Rennison DJ, Rosenberg MS, Winchell KM. Effects of urban-induced mutations on ecology, evolution and health. Nat Ecol Evol 2024; 8:1074-1086. [PMID: 38641700 DOI: 10.1038/s41559-024-02401-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 03/13/2024] [Indexed: 04/21/2024]
Abstract
Increasing evidence suggests that urbanization is associated with higher mutation rates, which can affect the health and evolution of organisms that inhabit cities. Elevated pollution levels in urban areas can induce DNA damage, leading to de novo mutations. Studies on mutations induced by urban pollution are most prevalent in humans and microorganisms, whereas studies of non-human eukaryotes are rare, even though increased mutation rates have the potential to affect organisms and their populations in contemporary time. Our Perspective explores how higher mutation rates in urban environments could impact the fitness, ecology and evolution of populations. Most mutations will be neutral or deleterious, and higher mutation rates associated with elevated pollution in urban populations can increase the risk of cancer in humans and potentially other species. We highlight the potential for urban-driven increased deleterious mutational loads in some organisms, which could lead to a decline in population growth of a wide diversity of organisms. Although beneficial mutations are expected to be rare, we argue that higher mutation rates in urban areas could influence adaptive evolution, especially in organisms with short generation times. Finally, we explore avenues for future research to better understand the effects of urban-induced mutations on the fitness, ecology and evolution of city-dwelling organisms.
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Affiliation(s)
- Marc T J Johnson
- Centre for Urban Environments, University of Toronto Mississauga, Mississauga, Ontario, Canada.
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada.
| | - Irtaqa Arif
- Centre for Urban Environments, University of Toronto Mississauga, Mississauga, Ontario, Canada
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Francesco Marchetti
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Jason Munshi-South
- Department of Biology and Louis Calder Center, Fordham University, Armonk, NY, USA
| | - Rob W Ness
- Centre for Urban Environments, University of Toronto Mississauga, Mississauga, Ontario, Canada
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Marta Szulkin
- Institute of Evolutionary Biology, Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
| | - Brian C Verrelli
- Center for Biological Data Science, Virginia Commonwealth University, Richmond, VA, USA
| | - Carole L Yauk
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Daniel N Anstett
- Department of Plant Biology, Department of Entomology, Plant Resilience Institute, Michigan State University, East Lansing, MI, USA
| | - Warren Booth
- Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Aude E Caizergues
- Centre for Urban Environments, University of Toronto Mississauga, Mississauga, Ontario, Canada
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Elizabeth J Carlen
- Living Earth Collaborative, Washington University in St. Louis, St. Louis, MO, USA
| | - Anthony Dant
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA
| | - Josefa González
- Institute of Evolutionary Biology, CSIC, UPF, Barcelona, Spain
| | - César González Lagos
- Departamento de Ciencias, Facultad de Artes Liberales, Universidad Adolfo Ibáñez, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
| | - Madeleine Oman
- Centre for Urban Environments, University of Toronto Mississauga, Mississauga, Ontario, Canada
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | | | - Diana J Rennison
- School of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Michael S Rosenberg
- Center for Biological Data Science, Virginia Commonwealth University, Richmond, VA, USA
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5
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Seo JE, Le Y, Revollo J, Miranda-Colon J, Xu H, McKinzie P, Mei N, Chen T, Heflich RH, Zhou T, Robison T, Bonzo JA, Guo X. Evaluating the mutagenicity of N-nitrosodimethylamine in 2D and 3D HepaRG cell cultures using error-corrected next generation sequencing. Arch Toxicol 2024; 98:1919-1935. [PMID: 38584193 PMCID: PMC11106104 DOI: 10.1007/s00204-024-03731-4] [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: 11/12/2023] [Accepted: 03/07/2024] [Indexed: 04/09/2024]
Abstract
Human liver-derived metabolically competent HepaRG cells have been successfully employed in both two-dimensional (2D) and 3D spheroid formats for performing the comet assay and micronucleus (MN) assay. In the present study, we have investigated expanding the genotoxicity endpoints evaluated in HepaRG cells by detecting mutagenesis using two error-corrected next generation sequencing (ecNGS) technologies, Duplex Sequencing (DS) and High-Fidelity (HiFi) Sequencing. Both HepaRG 2D cells and 3D spheroids were exposed for 72 h to N-nitrosodimethylamine (NDMA), followed by an additional incubation for the fixation of induced mutations. NDMA-induced DNA damage, chromosomal damage, and mutagenesis were determined using the comet assay, MN assay, and ecNGS, respectively. The 72-h treatment with NDMA resulted in concentration-dependent increases in cytotoxicity, DNA damage, MN formation, and mutation frequency in both 2D and 3D cultures, with greater responses observed in the 3D spheroids compared to 2D cells. The mutational spectrum analysis showed that NDMA induced predominantly A:T → G:C transitions, along with a lower frequency of G:C → A:T transitions, and exhibited a different trinucleotide signature relative to the negative control. These results demonstrate that the HepaRG 2D cells and 3D spheroid models can be used for mutagenesis assessment using both DS and HiFi Sequencing, with the caveat that severe cytotoxic concentrations should be avoided when conducting DS. With further validation, the HepaRG 2D/3D system may become a powerful human-based metabolically competent platform for genotoxicity testing.
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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
| | - Yuan Le
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Javier Revollo
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Jaime Miranda-Colon
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Hannah Xu
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Page McKinzie
- 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
| | - Tao Chen
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Robert H Heflich
- 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
| | - Timothy Robison
- Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Jessica A Bonzo
- Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, 20993, 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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6
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Kopp B, Khawam A, Di Perna K, Lenart D, Vinette M, Silva R, Zanoni TB, Rore C, Guenigault G, Richardson E, Kostrzewski T, Boswell A, Van P, Valentine Iii C, Salk J, Hamel A. Liver-on-chip model and application in predictive genotoxicity and mutagenicity of drugs. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2024; 896:503762. [PMID: 38821675 DOI: 10.1016/j.mrgentox.2024.503762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 04/04/2024] [Accepted: 04/08/2024] [Indexed: 06/02/2024]
Abstract
Currently, there is no test system, whether in vitro or in vivo, capable of examining all endpoints required for genotoxicity evaluation used in pre-clinical drug safety assessment. The objective of this study was to develop a model which could assess all the required endpoints and possesses robust human metabolic activity, that could be used in a streamlined, animal-free manner. Liver-on-chip (LOC) models have intrinsic human metabolic activity that mimics the in vivo environment, making it a preferred test system. For our assay, the LOC was assembled using primary human hepatocytes or HepaRG cells, in a MPS-T12 plate, maintained under microfluidic flow conditions using the PhysioMimix® Microphysiological System (MPS), and co-cultured with human lymphoblastoid (TK6) cells in transwells. This system allows for interaction between two compartments and for the analysis of three different genotoxic endpoints, i.e. DNA strand breaks (comet assay) in hepatocytes, chromosome loss or damage (micronucleus assay) and mutation (Duplex Sequencing) in TK6 cells. Both compartments were treated at 0, 24 and 45 h with two direct genotoxicants: methyl methanesulfonate (MMS) and ethyl methanesulfonate (EMS), and two genotoxicants requiring metabolic activation: benzo[a]pyrene (B[a]P) and cyclophosphamide (CP). Assessment of cytochrome activity, RNA expression, albumin, urea and lactate dehydrogenase production, demonstrated functional metabolic capacities. Genotoxicity responses were observed for all endpoints with MMS and EMS. Increases in the micronucleus and mutations (MF) frequencies were also observed with CP, and %Tail DNA with B[a]P, indicating the metabolic competency of the test system. CP did not exhibit an increase in the %Tail DNA, which is in line with in vivo data. However, B[a]P did not exhibit an increase in the % micronucleus and MF, which might require an optimization of the test system. In conclusion, this proof-of-principle experiment suggests that LOC-MPS technology is a promising tool for in vitro hazard identification genotoxicants.
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Affiliation(s)
- B Kopp
- Charles River Laboratories Montreal ULC, Canada
| | - A Khawam
- Charles River Laboratories Montreal ULC, Canada
| | - K Di Perna
- Charles River Laboratories Montreal ULC, Canada
| | - D Lenart
- Charles River Laboratories Montreal ULC, Canada
| | - M Vinette
- Charles River Laboratories Montreal ULC, Canada
| | - R Silva
- CN Bio Innovations, Cambridge, United Kingdom
| | - T B Zanoni
- TwinStrand Biosciences, Seattle, United States
| | - C Rore
- CN Bio Innovations, Cambridge, United Kingdom
| | | | | | | | - A Boswell
- TwinStrand Biosciences, Seattle, United States
| | - P Van
- TwinStrand Biosciences, Seattle, United States
| | | | - J Salk
- TwinStrand Biosciences, Seattle, United States
| | - A Hamel
- Charles River Laboratories Montreal ULC, Canada.
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7
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Bassan A, Steigerwalt R, Keller D, Beilke L, Bradley PM, Bringezu F, Brock WJ, Burns-Naas LA, Chambers J, Cross K, Dorato M, Elespuru R, Fuhrer D, Hall F, Hartke J, Jahnke GD, Kluxen FM, McDuffie E, Schmidt F, Valentin JP, Woolley D, Zane D, Myatt GJ. Developing a pragmatic consensus procedure supporting the ICH S1B(R1) weight of evidence carcinogenicity assessment. FRONTIERS IN TOXICOLOGY 2024; 6:1370045. [PMID: 38646442 PMCID: PMC11027748 DOI: 10.3389/ftox.2024.1370045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Accepted: 03/04/2024] [Indexed: 04/23/2024] Open
Abstract
The ICH S1B carcinogenicity global testing guideline has been recently revised with a novel addendum that describes a comprehensive integrated Weight of Evidence (WoE) approach to determine the need for a 2-year rat carcinogenicity study. In the present work, experts from different organizations have joined efforts to standardize as much as possible a procedural framework for the integration of evidence associated with the different ICH S1B(R1) WoE criteria. The framework uses a pragmatic consensus procedure for carcinogenicity hazard assessment to facilitate transparent, consistent, and documented decision-making and it discusses best-practices both for the organization of studies and presentation of data in a format suitable for regulatory review. First, it is acknowledged that the six WoE factors described in the addendum form an integrated network of evidence within a holistic assessment framework that is used synergistically to analyze and explain safety signals. Second, the proposed standardized procedure builds upon different considerations related to the primary sources of evidence, mechanistic analysis, alternative methodologies and novel investigative approaches, metabolites, and reliability of the data and other acquired information. Each of the six WoE factors is described highlighting how they can contribute evidence for the overall WoE assessment. A suggested reporting format to summarize the cross-integration of evidence from the different WoE factors is also presented. This work also notes that even if a 2-year rat study is ultimately required, creating a WoE assessment is valuable in understanding the specific factors and levels of human carcinogenic risk better than have been identified previously with the 2-year rat bioassay alone.
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Affiliation(s)
| | | | - Douglas Keller
- Independent Consultant, Kennett Square, PA, United States
| | - Lisa Beilke
- Toxicology Solutions, Inc., Marana, AZ, United States
| | | | - Frank Bringezu
- Chemical and Preclinical Safety, Merck Healthcare KGaA, Darmstadt, Germany
| | - William J. Brock
- Brock Scientific Consulting, LLC, Hilton Head, SC, United States
| | | | | | | | | | | | - Douglas Fuhrer
- BioXcel Therapeutics, Inc., New Haven, CT, United States
| | | | - Jim Hartke
- Gilead Sciences, Inc., Foster City, CA, United States
| | | | | | - Eric McDuffie
- Neurocrine Bioscience, Inc., San Diego, CA, United States
| | | | | | | | - Doris Zane
- Gilead Sciences, Inc., Foster City, CA, United States
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8
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Beal MA, Chen G, Dearfield KL, Gi M, Gollapudi B, Heflich RH, Horibata K, Long AS, Lovell DP, Parsons BL, Pfuhler S, Wills J, Zeller A, Johnson G, White PA. Interpretation of in vitro concentration-response data for risk assessment and regulatory decision-making: Report from the 2022 IWGT quantitative analysis expert working group meeting. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2023. [PMID: 38115239 DOI: 10.1002/em.22582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 09/15/2023] [Accepted: 12/16/2023] [Indexed: 12/21/2023]
Abstract
Quantitative risk assessments of chemicals are routinely performed using in vivo data from rodents; however, there is growing recognition that non-animal approaches can be human-relevant alternatives. There is an urgent need to build confidence in non-animal alternatives given the international support to reduce the use of animals in toxicity testing where possible. In order for scientists and risk assessors to prepare for this paradigm shift in toxicity assessment, standardization and consensus on in vitro testing strategies and data interpretation will need to be established. To address this issue, an Expert Working Group (EWG) of the 8th International Workshop on Genotoxicity Testing (IWGT) evaluated the utility of quantitative in vitro genotoxicity concentration-response data for risk assessment. The EWG first evaluated available in vitro methodologies and then examined the variability and maximal response of in vitro tests to estimate biologically relevant values for the critical effect sizes considered adverse or unacceptable. Next, the EWG reviewed the approaches and computational models employed to provide human-relevant dose context to in vitro data. Lastly, the EWG evaluated risk assessment applications for which in vitro data are ready for use and applications where further work is required. The EWG concluded that in vitro genotoxicity concentration-response data can be interpreted in a risk assessment context. However, prior to routine use in regulatory settings, further research will be required to address the remaining uncertainties and limitations.
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Affiliation(s)
- Marc A Beal
- Bureau of Chemical Safety, Health Products and Food Branch, Health Canada, Ottawa, Ontario, Canada
| | - Guangchao Chen
- Centre for Nutrition, Prevention and Health Services, National Institute for Public Health and the Environment (RIVM), Utrecht, the Netherlands
| | - Kerry L Dearfield
- Retired from US Environmental Protection Agency and US Department of Agriculture, Washington, DC, USA
| | - Min Gi
- Department of Environmental Risk Assessment, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
| | | | - Robert H Heflich
- National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas, USA
| | - Katsuyoshi Horibata
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, Kawasaki, Kanagawa, Japan
| | - Alexandra S Long
- Existing Substances Risk Assessment Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada
| | - David P Lovell
- St George's Medical School, University of London, London, UK
| | - Barbara L Parsons
- National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas, USA
| | - Stefan Pfuhler
- Global Product Stewardship - Human Safety, Procter & Gamble, Cincinnati, Ohio, USA
| | - John Wills
- Genetic Toxicology and Photosafety, GSK Research & Development, Stevenage, UK
| | - Andreas Zeller
- Pharmaceutical Sciences, pRED Innovation Center Basel, Hoffmann-La Roche Ltd, Basel, Switzerland
| | - George Johnson
- Swansea University Medical School, Swansea University, Swansea, UK
| | - Paul A White
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada
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9
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You X, Cao Y, Suzuki T, Shao J, Zhu B, Masumura K, Xi J, Liu W, Zhang X, Luan Y. Genome-wide direct quantification of in vivo mutagenesis using high-accuracy paired-end and complementary consensus sequencing. Nucleic Acids Res 2023; 51:e109. [PMID: 37870450 PMCID: PMC10681716 DOI: 10.1093/nar/gkad909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 09/25/2023] [Accepted: 10/05/2023] [Indexed: 10/24/2023] Open
Abstract
Error-corrected next-generation sequencing (ecNGS) is an emerging technology for accurately measuring somatic mutations. Here, we report paired-end and complementary consensus sequencing (PECC-Seq), a high-accuracy ecNGS approach for genome-wide somatic mutation detection. We characterize a novel 2-aminoimidazolone lesion besides 7,8-dihydro-8-oxoguanine and the resulting end-repair artifacts originating from NGS library preparation that obscure the sequencing accuracy of NGS. We modify library preparation protocol for the enzymatic removal of end-repair artifacts and improve the accuracy of our previously developed duplex consensus sequencing method. Optimized PECC-Seq shows an error rate of <5 × 10-8 with consensus bases compressed from approximately 25 Gb of raw sequencing data, enabling the accurate detection of low-abundance somatic mutations. We apply PECC-Seq to the quantification of in vivo mutagenesis. Compared with the classic gpt gene mutation assay using gpt delta transgenic mice, PECC-Seq exhibits high sensitivity in quantitatively measuring dose-dependent mutagenesis induced by Aristolochic acid I (AAI). Moreover, PECC-Seq specifically characterizes the distinct genome-wide mutational signatures of AAI, Benzo[a]pyrene, N-Nitroso-N-ethylurea and N-nitrosodiethylamine and reveals the mutational signature of Quinoline in common mouse models. Overall, our findings demonstrate that high-accuracy PECC-Seq is a promising tool for genome-wide somatic mutagenesis quantification and for in vivo mutagenicity testing.
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Affiliation(s)
- Xinyue You
- School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yiyi Cao
- School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Takayoshi Suzuki
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, Kawasaki 210-9501, Japan
| | - Jie Shao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, The Chinese Academy of Sciences, Beijing 100085, China; The University of Chinese Academy of Sciences, Beijing 100049, China
| | - Benzhan Zhu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, The Chinese Academy of Sciences, Beijing 100085, China; The University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kenichi Masumura
- Division of Risk Assessment, National Institute of Health Sciences, Kawasaki 210-9501, Japan
| | - Jing Xi
- School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Weiying Liu
- School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xinyu Zhang
- School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yang Luan
- School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
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10
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Smith-Roe SL, Hobbs CA, Hull V, Todd Auman J, Recio L, Streicker MA, Rivas MV, Pratt GA, Lo FY, Higgins JE, Schmidt EK, Williams LN, Nachmanson D, Valentine Iii CC, Salk JJ, Witt KL. Adopting duplex sequencing technology for genetic toxicity testing: A proof-of-concept mutagenesis experiment with N-ethyl-N-nitrosourea (ENU)-exposed rats. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2023; 891:503669. [PMID: 37770135 PMCID: PMC10539650 DOI: 10.1016/j.mrgentox.2023.503669] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 07/31/2023] [Accepted: 08/01/2023] [Indexed: 09/30/2023]
Abstract
Duplex sequencing (DS) is an error-corrected next-generation sequencing method in which molecular barcodes informatically link PCR-copies back to their source DNA strands, enabling computational removal of errors in consensus sequences. The resulting background of less than one artifactual mutation per 107 nucleotides allows for direct detection of somatic mutations. TwinStrand Biosciences, Inc. has developed a DS-based mutagenesis assay to sample the rat genome, which can be applied to genetic toxicity testing. To evaluate this assay for early detection of mutagenesis, a time-course study was conducted using male Hsd:Sprague Dawley SD rats (3 per group) administered a single dose of 40 mg/kg N-ethyl-N-nitrosourea (ENU) via gavage, with mutation frequency (MF) and spectrum analyzed in stomach, bone marrow, blood, and liver tissues at 3 h, 24 h, 7 d, and 28 d post-exposure. Significant increases in MF were observed in ENU-exposed rats as early as 24 h for stomach (site of contact) and bone marrow (a highly proliferative tissue) and at 7 d for liver and blood. The canonical, mutational signature of ENU was established by 7 d post-exposure in all four tissues. Interlaboratory analysis of a subset of samples from different tissues and time points demonstrated remarkable reproducibility for both MF and spectrum. These results demonstrate that MF and spectrum can be evaluated successfully by directly sequencing targeted regions of DNA obtained from various tissues, a considerable advancement compared to currently used in vivo gene mutation assays.
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Affiliation(s)
| | - Cheryl A Hobbs
- Integrated Laboratory Systems, LLC (An Inotiv Company), Research Triangle Park, NC, USA
| | - Victoria Hull
- Integrated Laboratory Systems, LLC (An Inotiv Company), Research Triangle Park, NC, USA
| | - J Todd Auman
- Integrated Laboratory Systems, LLC (An Inotiv Company), Research Triangle Park, NC, USA
| | - Leslie Recio
- Integrated Laboratory Systems, LLC (An Inotiv Company), Research Triangle Park, NC, USA
| | - Michael A Streicker
- Integrated Laboratory Systems, LLC (An Inotiv Company), Research Triangle Park, NC, USA
| | - Miriam V Rivas
- Integrated Laboratory Systems, LLC (An Inotiv Company), Research Triangle Park, NC, USA
| | | | - Fang Yin Lo
- TwinStrand Biosciences, Inc., Seattle, WA, USA
| | | | | | | | | | | | | | - Kristine L Witt
- Division of Translational Toxicology, NIEHS, Research Triangle Park, NC, USA
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11
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Seo JE, Yu JZ, Xu H, Li X, Atrakchi AH, McGovern TJ, Bruno KLD, Mei N, Heflich RH, Guo X. Genotoxicity assessment of eight nitrosamines using 2D and 3D HepaRG cell models. Arch Toxicol 2023; 97:2785-2798. [PMID: 37486449 DOI: 10.1007/s00204-023-03560-x] [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: 05/22/2023] [Accepted: 07/13/2023] [Indexed: 07/25/2023]
Abstract
N-nitrosamine impurities have been increasingly detected in human drugs. This is a safety concern as many nitrosamines are mutagenic in bacteria and carcinogenic in rodent models. Typically, the mutagenic and carcinogenic activity of nitrosamines requires metabolic activation by cytochromes P450 enzymes (CYPs), which in many in vitro models are supplied exogenously using rodent liver homogenates. There are only limited data on the genotoxicity of nitrosamines in human cell systems. In this study, we used metabolically competent human HepaRG cells, whose metabolic capability is comparable to that of primary human hepatocytes, to evaluate the genotoxicity of eight nitrosamines [N-cyclopentyl-4-nitrosopiperazine (CPNP), N-nitrosodibutylamine (NDBA), N-nitrosodiethylamine (NDEA), N-nitrosodimethylamine (NDMA), N-nitrosodiisopropylamine (NDIPA), N-nitrosoethylisopropylamine (NEIPA), N-nitroso-N-methyl-4-aminobutyric acid (NMBA), and N-nitrosomethylphenylamine (NMPA)]. Under the conditions we used to culture HepaRG cells, three-dimensional (3D) spheroids possessed higher levels of CYP activity compared to 2D monolayer cells; thus the genotoxicity of the eight nitrosamines was investigated using 3D HepaRG spheroids in addition to more conventional 2D cultures. Genotoxicity was assessed as DNA damage using the high-throughput CometChip assay and as aneugenicity/clastogenicity in the flow-cytometry-based micronucleus (MN) assay. Following a 24-h treatment, all the nitrosamines induced DNA damage in 3D spheroids, while only three nitrosamines, NDBA, NDEA, and NDMA, produced positive responses in 2D HepaRG cells. In addition, these three nitrosamines also caused significant increases in MN frequency in both 2D and 3D HepaRG models, while NMBA and NMPA were positive only in the 3D HepaRG MN assay. Overall, our results indicate that HepaRG spheroids may provide a sensitive, human-based cell system for evaluating the genotoxicity of nitrosamines.
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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
| | - Joshua Z Yu
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, 72079, USA
- Wiess School of Natural Sciences, Rice University, Houston, TX, 77005, USA
| | - Hannah Xu
- 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
| | - Aisar H Atrakchi
- Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Timothy J McGovern
- Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Karen L Davis Bruno
- Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Nan Mei
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Robert H Heflich
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Xiaoqing Guo
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, 72079, USA.
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12
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Menz J, Götz ME, Gündel U, Gürtler R, Herrmann K, Hessel-Pras S, Kneuer C, Kolrep F, Nitzsche D, Pabel U, Sachse B, Schmeisser S, Schumacher DM, Schwerdtle T, Tralau T, Zellmer S, Schäfer B. Genotoxicity assessment: opportunities, challenges and perspectives for quantitative evaluations of dose-response data. Arch Toxicol 2023; 97:2303-2328. [PMID: 37402810 PMCID: PMC10404208 DOI: 10.1007/s00204-023-03553-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 06/21/2023] [Indexed: 07/06/2023]
Abstract
Genotoxicity data are mainly interpreted in a qualitative way, which typically results in a binary classification of chemical entities. For more than a decade, there has been a discussion about the need for a paradigm shift in this regard. Here, we review current opportunities, challenges and perspectives for a more quantitative approach to genotoxicity assessment. Currently discussed opportunities mainly include the determination of a reference point (e.g., a benchmark dose) from genetic toxicity dose-response data, followed by calculation of a margin of exposure (MOE) or derivation of a health-based guidance value (HBGV). In addition to new opportunities, major challenges emerge with the quantitative interpretation of genotoxicity data. These are mainly rooted in the limited capability of standard in vivo genotoxicity testing methods to detect different types of genetic damage in multiple target tissues and the unknown quantitative relationships between measurable genotoxic effects and the probability of experiencing an adverse health outcome. In addition, with respect to DNA-reactive mutagens, the question arises whether the widely accepted assumption of a non-threshold dose-response relationship is at all compatible with the derivation of a HBGV. Therefore, at present, any quantitative genotoxicity assessment approach remains to be evaluated case-by-case. The quantitative interpretation of in vivo genotoxicity data for prioritization purposes, e.g., in connection with the MOE approach, could be seen as a promising opportunity for routine application. However, additional research is needed to assess whether it is possible to define a genotoxicity-derived MOE that can be considered indicative of a low level of concern. To further advance quantitative genotoxicity assessment, priority should be given to the development of new experimental methods to provide a deeper mechanistic understanding and a more comprehensive basis for the analysis of dose-response relationships.
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Affiliation(s)
- Jakob Menz
- Department of Food Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589, Berlin, Germany.
| | - Mario E Götz
- Department of Food Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Ulrike Gündel
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Rainer Gürtler
- Department of Food Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Kristin Herrmann
- Department of Pesticides Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Stefanie Hessel-Pras
- Department of Food Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Carsten Kneuer
- Department of Pesticides Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Franziska Kolrep
- Department of Safety in the Food Chain, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Dana Nitzsche
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Ulrike Pabel
- Department of Safety in the Food Chain, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Benjamin Sachse
- Department of Food Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Sebastian Schmeisser
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - David M Schumacher
- Department of Safety in the Food Chain, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Tanja Schwerdtle
- German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Tewes Tralau
- Department of Pesticides Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Sebastian Zellmer
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Bernd Schäfer
- Department of Food Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
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13
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Marchetti F, Cardoso R, Chen CL, Douglas GR, Elloway J, Escobar PA, Harper T, Heflich RH, Kidd D, Lynch AM, Myers MB, Parsons BL, Salk JJ, Settivari RS, Smith-Roe SL, Witt KL, Yauk CL, Young R, Zhang S, Minocherhomji S. Error-corrected next generation sequencing - Promises and challenges for genotoxicity and cancer risk assessment. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2023; 792:108466. [PMID: 37643677 DOI: 10.1016/j.mrrev.2023.108466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 07/12/2023] [Accepted: 08/23/2023] [Indexed: 08/31/2023]
Abstract
Error-corrected Next Generation Sequencing (ecNGS) is rapidly emerging as a valuable, highly sensitive and accurate method for detecting and characterizing mutations in any cell type, tissue or organism from which DNA can be isolated. Recent mutagenicity and carcinogenicity studies have used ecNGS to quantify drug-/chemical-induced mutations and mutational spectra associated with cancer risk. ecNGS has potential applications in genotoxicity assessment as a new readout for traditional models, for mutagenesis studies in 3D organotypic cultures, and for detecting off-target effects of gene editing tools. Additionally, early data suggest that ecNGS can measure clonal expansion of mutations as a mechanism-agnostic early marker of carcinogenic potential and can evaluate mutational load directly in human biomonitoring studies. In this review, we discuss promising applications, challenges, limitations, and key data initiatives needed to enable regulatory testing and adoption of ecNGS - including for advancing safety assessment, augmenting weight-of-evidence for mutagenicity and carcinogenicity mechanisms, identifying early biomarkers of cancer risk, and managing human health risk from chemical exposures.
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Affiliation(s)
| | | | - Connie L Chen
- Health and Environmental Sciences Institute, Washington, DC, USA.
| | | | - Joanne Elloway
- Safety Sciences, Clinical Pharmacology & Safety Sciences, R&D, AstraZeneca, Cambridge, UK
| | | | - Tod Harper
- Amgen Research, Amgen Inc, Thousand Oaks, CA, USA
| | - Robert H Heflich
- US Food and Drug Administration/National Center for Toxicological Research, Jefferson, AR, USA
| | - Darren Kidd
- Labcorp Early Development Laboratories Limited, Harrogate, North Yorkshire, UK
| | | | - Meagan B Myers
- US Food and Drug Administration/National Center for Toxicological Research, Jefferson, AR, USA
| | - Barbara L Parsons
- US Food and Drug Administration/National Center for Toxicological Research, Jefferson, AR, USA
| | | | | | | | - Kristine L Witt
- NIEHS, Division of the National Toxicology Program, Research Triangle Park, NC, USA
| | | | - Robert Young
- MilliporeSigma, Rockville, MD, USA; Current: Consultant, Bethesda, MD, USA
| | | | - Sheroy Minocherhomji
- Amgen Research, Amgen Inc, Thousand Oaks, CA, USA; Current: Eli Lilly and Company, Indianapolis, IN, USA
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14
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Menon V, Brash DE. Next-generation sequencing methodologies to detect low-frequency mutations: "Catch me if you can". MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2023; 792:108471. [PMID: 37716438 PMCID: PMC10843083 DOI: 10.1016/j.mrrev.2023.108471] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 09/06/2023] [Accepted: 09/07/2023] [Indexed: 09/18/2023]
Abstract
Mutations, the irreversible changes in an organism's DNA sequence, are present in tissues at a variant allele frequency (VAF) ranging from ∼10-8 per bp for a founder mutation to ∼10-3 for a histologically normal tissue sample containing several independent clones - compared to 1%- 50% for a heterozygous tumor mutation or a polymorphism. The rarity of these events poses a challenge for accurate clinical diagnosis and prognosis, toxicology, and discovering new disease etiologies. Standard Next-Generation Sequencing (NGS) technologies report VAFs as low as 0.5% per nt, but reliably observing rarer precursor events requires additional sophistication to measure ultralow-frequency mutations. We detail the challenge; define terms used to characterize the results, which vary between laboratories and sometimes conflict between biologists and bioinformaticists; and describe recent innovations to improve standard NGS methodologies including: single-strand consensus sequence methods such as Safe-SeqS and SiMSen-Seq; tandem-strand consensus sequence methods such as o2n-Seq and SMM-Seq; and ultrasensitive parent-strand consensus sequence methods such as DuplexSeq, PacBio HiFi, SinoDuplex, OPUSeq, EcoSeq, BotSeqS, Hawk-Seq, NanoSeq, SaferSeq, and CODEC. Practical applications are also noted. Several methods quantify VAF down to 10-5 at a nt and mutation frequency (MF) in a target region down to 10-7 per nt. By expanding to > 1 Mb of sites never observed twice, thus forgoing VAF, other methods quantify MF < 10-9 per nt or < 15 errors per haploid genome. Clonal expansion cannot be directly distinguished from independent mutations by sequencing, so it is essential for a paper to report whether its MF counted only different mutations - the minimum independent-mutation frequency MFminI - or all mutations observed including recurrences - the larger maximum independent-mutation frequency MFmaxI which may reflect clonal expansion. Ultrasensitive methods reveal that, without their use, even mutations with VAF 0.5-1% are usually spurious.
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Affiliation(s)
- Vijay Menon
- Department of Therapeutic Radiology, Yale School of Medicine, New Haven, CT 06520-8040, USA.
| | - Douglas E Brash
- Department of Therapeutic Radiology, Yale School of Medicine, New Haven, CT 06520-8040, USA; Department of Dermatology, Yale School of Medicine, New Haven, CT 06520-8059, USA; Yale Cancer Center, Yale School of Medicine, New Haven, CT 06520-8028, USA.
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15
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Cho E, Swartz CD, Williams A, V Rivas M, Recio L, Witt KL, Schmidt EK, Yaplee J, Smith TH, Van P, Lo FY, Valentine CC, Salk JJ, Marchetti F, Smith-Roe SL, Yauk CL. Error-corrected duplex sequencing enables direct detection and quantification of mutations in human TK6 cells with strong inter-laboratory consistency. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2023; 889:503649. [PMID: 37491114 PMCID: PMC10395007 DOI: 10.1016/j.mrgentox.2023.503649] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 05/12/2023] [Accepted: 05/18/2023] [Indexed: 07/27/2023]
Abstract
Error-corrected duplex sequencing (DS) enables direct quantification of low-frequency mutations and offers tremendous potential for chemical mutagenicity assessment. We investigated the utility of DS to quantify induced mutation frequency (MF) and spectrum in human lymphoblastoid TK6 cells exposed to a prototypical DNA alkylating agent, N-ethyl-N-nitrosourea (ENU). Furthermore, we explored appropriate experimental parameters for this application, and assessed inter-laboratory reproducibility. In two independent experiments in two laboratories, TK6 cells were exposed to ENU (25-200 µM) and DNA was sequenced 48, 72, and 96 h post-exposure. A DS mutagenicity panel targeting twenty 2.4-kb regions distributed across the genome was used to sample diverse, genome-representative sequence contexts. A significant increase in MF that was unaffected by time was observed in both laboratories. Concentration-response in the MF from the two laboratories was strongly positively correlated (r = 0.97). C:G>T:A, T:A>C:G, T:A>A:T, and T:A>G:C mutations increased in consistent, concentration-dependent manners in both laboratories, with high proportions of C:G>T:A at all time points. The consistent results across the three time points suggest that 48 h may be sufficient for mutation analysis post-exposure. The target sites responded similarly between the two laboratories and revealed a higher average MF in intergenic regions. These results, demonstrating remarkable reproducibility across time and laboratory for both MF and spectrum, support the high value of DS for characterizing chemical mutagenicity in both research and regulatory evaluation.
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Affiliation(s)
- Eunnara Cho
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada; Department of Biology, Carleton University, Ottawa, ON, Canada
| | | | - Andrew Williams
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | | | - Leslie Recio
- Inotiv-RTP, Research Triangle Park, NC, USA; Scitovation, Research Triangle Park, NC, USA
| | - Kristine L Witt
- Division of Translational Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | | | | | | | - Phu Van
- TwinStrand Biosciences, Inc., Seattle, WA, USA
| | - Fang Yin Lo
- TwinStrand Biosciences, Inc., Seattle, WA, USA
| | | | | | - Francesco Marchetti
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada; Department of Biology, Carleton University, Ottawa, ON, Canada
| | - Stephanie L Smith-Roe
- Division of Translational Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA.
| | - Carole L Yauk
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada; Department of Biology, Carleton University, Ottawa, ON, Canada; Department of Biology, University of Ottawa, Ottawa, ON, Canada.
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16
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Smith-Roe SL, Hobbs CA, Hull V, Auman JT, Recio L, Streicker MA, Rivas MV, Pratt GA, Lo FY, Higgins JE, Schmidt EK, Williams LN, Nachmanson D, Valentine CC, Salk JJ, Witt KL. Adopting Duplex Sequencing™ Technology for Genetic Toxicity Testing: A Proof-of-Concept Mutagenesis Experiment with N-Ethyl-N-Nitrosourea (ENU)-Exposed Rats. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.08.539833. [PMID: 37214853 PMCID: PMC10197591 DOI: 10.1101/2023.05.08.539833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Duplex sequencing (DuplexSeq) is an error-corrected next-generation sequencing (ecNGS) method in which molecular barcodes informatically link PCR-copies back to their source DNA strands, enabling computational removal of errors by comparing grouped strand sequencing reads. The resulting background of less than one artifactual mutation per 10 7 nucleotides allows for direct detection of somatic mutations. TwinStrand Biosciences, Inc. has developed a DuplexSeq-based mutagenesis assay to sample the rat genome, which can be applied to genetic toxicity testing. To evaluate this assay for early detection of mutagenesis, a time-course study was conducted using male Hsd:Sprague Dawley SD rats (3 per group) administered a single dose of 40 mg/kg N-ethyl-N-nitrosourea (ENU) via gavage, with mutation frequency (MF) and spectrum analyzed in stomach, bone marrow, blood, and liver tissues at 3 h, 24 h, 7 d, and 28 d post-exposure. Significant increases in MF were observed in ENU-exposed rats as early as 24 h for stomach (site of contact) and bone marrow (a highly proliferative tissue) and at 7 d for liver and blood. The canonical, mutational signature of ENU was established by 7 d post-exposure in all four tissues. Interlaboratory analysis of a subset of samples from different tissues and time points demonstrated remarkable reproducibility for both MF and spectrum. These results demonstrate that MF and spectrum can be evaluated successfully by directly sequencing targeted regions of DNA obtained from various tissues, a considerable advancement compared to currently used in vivo gene mutation assays. HIGHLIGHTS DuplexSeq is an ultra-accurate NGS technology that directly quantifies mutationsENU-dependent mutagenesis was detected 24 h post-exposure in proliferative tissuesMultiple tissues exhibited the canonical ENU mutation spectrum 7 d after exposureResults obtained with DuplexSeq were highly concordant between laboratoriesThe Rat-50 Mutagenesis Assay is promising for applications in genetic toxicology.
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Affiliation(s)
| | - Cheryl A. Hobbs
- Integrated Laboratory Systems, LLC (an Inotiv company), Research Triangle Park, NC
| | - Victoria Hull
- Integrated Laboratory Systems, LLC (an Inotiv company), Research Triangle Park, NC
| | - J. Todd Auman
- Integrated Laboratory Systems, LLC (an Inotiv company), Research Triangle Park, NC
| | - Leslie Recio
- Integrated Laboratory Systems, LLC (an Inotiv company), Research Triangle Park, NC
| | - Michael A. Streicker
- Integrated Laboratory Systems, LLC (an Inotiv company), Research Triangle Park, NC
| | - Miriam V. Rivas
- Integrated Laboratory Systems, LLC (an Inotiv company), Research Triangle Park, NC
| | | | | | | | | | | | | | | | | | - Kristine L. Witt
- Division of Translational Toxicology, NIEHS, Research Triangle Park, NC
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