1
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Chen M, Hei J, Huang Y, Liu X, Huang Y. In vivo safety evaluation method for nanomaterials for cancer therapy. Clin Transl Oncol 2024; 26:2126-2141. [PMID: 38573443 DOI: 10.1007/s12094-024-03466-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 03/13/2024] [Indexed: 04/05/2024]
Abstract
Nanomaterials are extensively used in the diagnosis and treatment of cancer and other diseases because of their distinctive physicochemical properties, including the small size and ease of modification. The approval of numerous nanomaterials for clinical treatment has led to a significant increase in human exposure to these materials. When nanomaterials enter organisms, they interact with DNA, cells, tissues, and organs, potentially causing various adverse effects, such as genotoxicity, reproductive toxicity, immunotoxicity, and damage to tissues and organs. Therefore, it is crucial to elucidate the side effects and toxicity mechanisms of nanomaterials thoroughly before their clinical applications. Although methods for in vitro safety evaluation of nanomaterials are well established, systematic methods for in vivo safety evaluation are still lacking. This review focuses on the in vivo safety evaluation of nanomaterials and explores their potential effects. In addition, the experimental methods for assessing such effects in various disciplines, including toxicology, pharmacology, physiopathology, immunology, and bioinformatics are also discussed.
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Affiliation(s)
- Mengqi Chen
- State Key Laboratory of Targeting Oncology, National Center for International Research of Bio-Targeting Theranostics, Guangxi Key Laboratory of Bio-Targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Jingyi Hei
- State Key Laboratory of Targeting Oncology, National Center for International Research of Bio-Targeting Theranostics, Guangxi Key Laboratory of Bio-Targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Yan Huang
- State Key Laboratory of Targeting Oncology, National Center for International Research of Bio-Targeting Theranostics, Guangxi Key Laboratory of Bio-Targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Xiyu Liu
- State Key Laboratory of Targeting Oncology, National Center for International Research of Bio-Targeting Theranostics, Guangxi Key Laboratory of Bio-Targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, Nanning, 530021, Guangxi, China.
| | - Yong Huang
- State Key Laboratory of Targeting Oncology, National Center for International Research of Bio-Targeting Theranostics, Guangxi Key Laboratory of Bio-Targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, Nanning, 530021, Guangxi, China.
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2
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Németh E, Szüts D. The mutagenic consequences of defective DNA repair. DNA Repair (Amst) 2024; 139:103694. [PMID: 38788323 DOI: 10.1016/j.dnarep.2024.103694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 05/10/2024] [Accepted: 05/14/2024] [Indexed: 05/26/2024]
Abstract
Multiple separate repair mechanisms safeguard the genome against various types of DNA damage, and their failure can increase the rate of spontaneous mutagenesis. The malfunction of distinct repair mechanisms leads to genomic instability through different mutagenic processes. For example, defective mismatch repair causes high base substitution rates and microsatellite instability, whereas homologous recombination deficiency is characteristically associated with deletions and chromosome instability. This review presents a comprehensive collection of all mutagenic phenotypes associated with the loss of each DNA repair mechanism, drawing on data from a variety of model organisms and mutagenesis assays, and placing greatest emphasis on systematic analyses of human cancer datasets. We describe the latest theories on the mechanism of each mutagenic process, often explained by reliance on an alternative repair pathway or the error-prone replication of unrepaired, damaged DNA. Aided by the concept of mutational signatures, the genomic phenotypes can be used in cancer diagnosis to identify defective DNA repair pathways.
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Affiliation(s)
- Eszter Németh
- Institute of Molecular Life Sciences, HUN-REN Research Centre for Natural Sciences, Budapest, Hungary
| | - Dávid Szüts
- Institute of Molecular Life Sciences, HUN-REN Research Centre for Natural Sciences, Budapest, Hungary.
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3
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Lynch AM, Howe J, Hildebrand D, Harvey JS, Burman M, Harte DSG, Chen L, Kmett C, Shi W, McHugh CF, Patel KK, Junnotula V, Kenny J, Haworth R, Wills JW. N-Nitrosodimethylamine investigations in Muta™Mouse define point-of-departure values and demonstrate less-than-additive somatic mutant frequency accumulations. Mutagenesis 2024; 39:96-118. [PMID: 38183622 DOI: 10.1093/mutage/geae001] [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: 11/13/2023] [Accepted: 01/05/2024] [Indexed: 01/08/2024] Open
Abstract
The N-nitrosamine, N-nitrosodimethylamine (NDMA), is an environmental mutagen and rodent carcinogen. Small levels of NDMA have been identified as an impurity in some commonly used drugs, resulting in several product recalls. In this study, NDMA was evaluated in an OECD TG-488 compliant Muta™Mouse gene mutation assay (28-day oral dosing across seven daily doses of 0.02-4 mg/kg/day) using an integrated design that assessed mutation at the transgenic lacZ locus in various tissues and at the endogenous Pig-a gene-locus, along with micronucleus frequencies in peripheral blood. Liver pathology was determined together with NDMA exposure in blood and liver. The additivity of mutation induction was assessed by including two acute single-dose treatment groups (i.e. 5 and 10 mg/kg dose on Day 1), which represented the same total dose as two of the repeat dose treatment groups. NDMA did not induce statistically significant increases in mean lacZ mutant frequency (MF) in bone marrow, spleen, bladder, or stomach, nor in peripheral blood (Pig-a mutation or micronucleus induction) when tested up to 4 mg/kg/day. There were dose-dependent increases in mean lacZ MF in the liver, lung, and kidney following 28-day repeat dosing or in the liver and kidney after a single dose (10 mg/kg). No observed genotoxic effect levels (NOGEL) were determined for the positive repeat dose-response relationships. Mutagenicity did not exhibit simple additivity in the liver since there was a reduction in MF following NDMA repeat dosing compared with acute dosing for the same total dose. Benchmark dose modelling was used to estimate point of departure doses for NDMA mutagenicity in Muta™Mouse and rank order target organ tissue sensitivity (liver > kidney or lung). The BMD50 value for liver was 0.32 mg/kg/day following repeat dosing (confidence interval 0.21-0.46 mg/kg/day). In addition, liver toxicity was observed at doses of ≥ 1.1 mg/kg/day NDMA and correlated with systemic and target organ exposure. The integration of these results and their implications for risk assessment are discussed.
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Affiliation(s)
- Anthony M Lynch
- Genetic Toxicology & Photosafety, GSK R&D, Stevenage, SG1 2NY, United Kingdom
| | - Jonathan Howe
- Genetic Toxicology & Photosafety, GSK R&D, Stevenage, SG1 2NY, United Kingdom
| | | | - James S Harvey
- Genetic Toxicology & Photosafety, GSK R&D, Stevenage, SG1 2NY, United Kingdom
| | - Mark Burman
- Genetic Toxicology & Photosafety, GSK R&D, Stevenage, SG1 2NY, United Kingdom
| | - Danielle S G Harte
- Genetic Toxicology & Photosafety, GSK R&D, Stevenage, SG1 2NY, United Kingdom
| | - Liangfu Chen
- DMPK, GSK R&D, Upper Providence, Collegeville, PA, United States
| | - Casey Kmett
- DMPK, GSK R&D, Upper Providence, Collegeville, PA, United States
| | - Wei Shi
- DMPK, GSK R&D, Upper Providence, Collegeville, PA, United States
| | - Charles F McHugh
- DMPK, GSK R&D, Upper Providence, Collegeville, PA, United States
| | - Kinnari K Patel
- BIB, GSK R&D, Upper Providence, Collegeville, PA, United States
| | | | - Julia Kenny
- TPPS, GSK R&D, Stevenage, SG1 2NY, United Kingdom
| | | | - John W Wills
- Genetic Toxicology & Photosafety, GSK R&D, Stevenage, SG1 2NY, United Kingdom
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Zhu X, Cao L, Liu Y, Tang X, Miao Y, Zhang J, Zhang L, Jia Z, Chen J. Genotoxicity of bisphenol AF in rats: Detrimental to male reproductive system and probable stronger micronucleus induction potency than BPA. J Appl Toxicol 2024; 44:428-444. [PMID: 37837293 DOI: 10.1002/jat.4552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 09/13/2023] [Accepted: 09/25/2023] [Indexed: 10/15/2023]
Abstract
Bisphenol AF (BPAF), as one of structural analogs of BPA, has been increasingly used in recent years. However, limited studies have suggested its adverse effects similar to or higher than BPA. In order to explore the general toxicity and genotoxicity of subacute exposure to BPAF, the novel 28-day multi-endpoint (Pig-a assay + micronucleus [MN] test + comet assay) genotoxicity evaluation platform was applied. Male rats were randomly distributed into seven main experimental groups and four satellite groups. The main experimental groups included BPAF-treated groups (0.5, 5, and 50 μg/kg·bw/d), BPA group (10 μg/kg·bw/d), two solvent control groups (PBS and 0.1% ethanol/99.9% oil), and one positive control group (N-ethyl-N-nitrosourea, 40 mg/kg bw). The satellite groups included BPAF high-dose recovery group (BPAF-HR), oil recovery group (oil-R), ENU recovery group (ENU-R), and PBS recovery group (PBS-R). All groups received the agents orally via gavage for 28 consecutive days, and satellite groups were given a recovery period of 35 days. Among all histopathologically examined organs, testis and epididymis damage was noticed, which was further manifested as blood-testis barrier (BTB) junction protein (Connexin 43 and Occludin) destruction. BPAF can induce micronucleus production and DNA damage, but the genotoxic injury can be repaired after the recovery period. The expression of DNA repair gene OGG1 was downregulated by BPAF. To summarize, under the design of this experiment, male reproductive toxicity of BPAF was noticed, which is similar to that of BPA, but its ability to induce micronucleus production may be stronger than that of BPA.
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Affiliation(s)
- Xia Zhu
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
- Second People's Hospital of Yibin City, Yibin, China
| | - Li Cao
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, China
| | - Yufei Liu
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, China
| | - Xinyao Tang
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, China
| | - Yeqiu Miao
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, China
| | - Jing Zhang
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, China
| | - Lishi Zhang
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, China
| | - Zhenchao Jia
- Department of Prevention and Health Care, Sichuan University Hospital of Sichuan University, Chengdu, China
| | - Jinyao Chen
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, China
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Dobrovolsky VN, Atiq OT, Heflich RH, Maisha M, McKinzie PB, Pearce MG, Robison TW. Erythrocyte PIG-A mutant frequencies in cancer patients receiving cisplatin. Cancer Med 2024; 13:e6895. [PMID: 38214136 PMCID: PMC10905239 DOI: 10.1002/cam4.6895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 12/04/2023] [Accepted: 12/19/2023] [Indexed: 01/13/2024] Open
Abstract
BACKGROUND Cisplatin is a primary chemotherapy choice for various solid tumors. DNA damage caused by cisplatin results in apoptosis of tumor cells. Cisplatin-induced DNA damage, however, may also result in mutations in normal cells and the initiation of secondary malignancies. In the current study, we have used the erythrocyte PIG-A assay to evaluate mutagenesis in non-tumor hematopoietic tissue of cancer patients receiving cisplatin chemotherapy. METHODS Twenty-one head and neck cancer patients undergoing treatment with cisplatin were monitored for the presence of PIG-A mutant total erythrocytes and the young erythrocytes, reticulocytes (RETs), in peripheral blood for up to five and a half months from the initiation of the anti-neoplastic chemotherapy. RESULTS PIG-A mutant frequency (MF) in RETs increased at least two-fold in 15 patients at some point of the monitoring, while the frequency of total mutant RBCs increased at least two-fold in 6 patients. A general trend for an increase in the frequency of mutant RETs and total mutant RBCs was observed in 19 and 18 patients, respectively. Only in one patient did both RET and total RBC PIG-A MFs did not increase at any time-point over the monitoring period. CONCLUSION Cisplatin chemotherapy induces moderate increases in the frequency of PIG-A mutant erythrocytes in head and neck cancer patients. Mutagenicity measured with the flow cytometric PIG-A assay may serve as a tool for predicting adverse outcomes of genotoxic antineoplastic therapy.
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Affiliation(s)
- Vasily N. Dobrovolsky
- Division of Genetic and Molecular ToxicologyNational Center for Toxicological Research (NCTR), US Food and Drug Administration (FDA)JeffersonArkansasUSA
| | - Omar T. Atiq
- University of Arkansas for Medical Sciences (UAMS) Winthrop P. Rockefeller Cancer InstituteLittle RockArkansasUSA
| | - Robert H. Heflich
- Division of Genetic and Molecular ToxicologyNational Center for Toxicological Research (NCTR), US Food and Drug Administration (FDA)JeffersonArkansasUSA
| | - Mackean Maisha
- Office of Scientific Coordination, NCTR, FDAJeffersonArkansasUSA
| | - Page B. McKinzie
- Division of Genetic and Molecular ToxicologyNational Center for Toxicological Research (NCTR), US Food and Drug Administration (FDA)JeffersonArkansasUSA
| | - Mason G. Pearce
- Division of Genetic and Molecular ToxicologyNational Center for Toxicological Research (NCTR), US Food and Drug Administration (FDA)JeffersonArkansasUSA
| | - Timothy W. Robison
- Office of New Drugs, OII, DPTII, Center for Drug Evaluation and Research (CDER), US FDASilver SpringMarylandUSA
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Gollapudi BB. Investigations on the genotoxic potential of styrene in Fischer 344 rats using multiple endpoints. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2024; 65:67-75. [PMID: 38525651 DOI: 10.1002/em.22590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Accepted: 03/04/2024] [Indexed: 03/26/2024]
Abstract
Genotoxicity of styrene monomer was evaluated in male Fischer 344 rats using the alkaline comet assay for DNA damage, micronucleus assay for cytogenetic damage and the Pig-a assay for gene mutations. In a dose range finding (DRF) study, styrene was administered by oral gavage in corn oil for 28 consecutive days at 0, 100, 500, and 1000 mg/kg/day. The bioavailability of styrene was confirmed in the DRF by measuring its plasma levels at approximately 7- or 15-min following dosing. The 1000 mg/kg/day group exceeded the maximum tolerated dose based on body weight and organ weight changes and signs of central nervous system depression. Based on these findings, doses of 0, 100, 250, and 500 mg/kg/day (for 28 or 29 days) were selected for the genotoxicity assays. Animals were sacrificed 3-4 h after treatment on Day 28 or 29 for assessing various genotoxicity endpoints. Pig-a mutant frequencies and micronucleus frequencies were determined in peripheral blood erythrocytes. The comet assay was conducted in the glandular stomach, duodenum, liver, lung, and kidney. These studies were conducted in accordance with the relevant OECD test guidelines. Oral administration of styrene did not lead to genotoxicity in any of the investigated endpoints. The adequacy of the experimental conditions was assured by including animals treated by oral gavage with the positive control chemicals ethyl nitrosourea and ethyl methane sulfonate. Results from these studies supplement to the growing body of evidence suggesting the lack of in vivo genotoxic potential for styrene.
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Dobrovolsky VN, Matsuda T, McKinzie P, Miranda J, Revollo JR. Whole-genome high-fidelity sequencing: A novel approach to detecting and characterization of mutagenicity in vivo. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2023; 891:503691. [PMID: 37770148 DOI: 10.1016/j.mrgentox.2023.503691] [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: 02/14/2023] [Revised: 08/29/2023] [Accepted: 09/04/2023] [Indexed: 10/03/2023]
Abstract
Direct DNA sequencing can be used for characterizing mutagenicity in simple and complex biological models. Recently we described a method of whole-genome sequencing for detecting mutations in simple models of cultured bacteria, mammalian cells, and nematode. In the current proof-of-concept study, we expand and improve our method for evaluating a more complex mammalian biological model in outbred mice. We detail the method by applying it to a small set of animals treated with a mutagen with known mutagenicity profiles, N-ethyl-N-nitrosourea (ENU), for consistency with the known data. Whole-genome high-fidelity sequencing (HiFi Sequencing) showed frequencies and spectra of background mutations in tissues of untreated mice that were consistent with normal ageing and characterized by spontaneous or enzymatic deamination of 5-methylcytosine. In mice treated with a single 40 mg/kg dose of ENU, the frequency of mutations in the genomic DNA of solid tissues increased up to 7-fold, with the greatest increase observed in the spleen and the smallest increase in the liver. The most common mutations detected in ENU-treated mice were T > A transitions and T > C transversions, consistent with the types of mutations caused by alkylating agents. The data suggest that HiFi Sequencing may be useful for characterizing mutagenicity of novel compounds in various biological models.
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Affiliation(s)
- Vasily N Dobrovolsky
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson AR, USA.
| | - Tomonari Matsuda
- Research Center for Environmental Quality Management, Kyoto University, Otsu, Shiga, Japan
| | - Page McKinzie
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson AR, USA
| | - Jaime Miranda
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson AR, USA
| | - Javier R Revollo
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson AR, USA
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Nichols L, Lawrence R, Haboubi H, Al-Sarireh B, Doak S, Jenkins G. Measuring blood cell DNA damage using the PIG-A mutation and CBMN assay in pancreatic cancer patients: a pilot study. Mutagenesis 2023; 38:93-99. [PMID: 37006185 PMCID: PMC10181792 DOI: 10.1093/mutage/gead006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 03/29/2023] [Indexed: 04/04/2023] Open
Abstract
Pancreatic cancer still has one of the worst prognoses of all solid malignancies, despite developments in cancer knowledge and care. Research into pancreatic cancer has not fully translated into clinical improvements and as a result, fewer than 1% of patients survive 10 years post-diagnosis. This bleak outlook for patients could be improved by earlier diagnosis. The human erythrocyte phosphatidylinositol glycan class A (PIG-A) assay monitors the mutation status of the X-linked PIG-A gene by measuring glycosyl phosphatidylinositol (GPI)-anchored proteins on the extracellular surface. We have previously identified an elevated PIG-A mutant frequency in oesophageal adenocarcinoma patients and here investigate whether this could be seen in a pancreatic cancer cohort, given the urgent need for novel pancreatic cancer biomarkers. In our pilot study, an elevated PIG-A mutant frequency (5.775 × 10-6 (95% CI 4.777-10) mutants per million) was seen in pancreatic cancer patients (n = 30) when compared to the non-cancer control group (n = 14) who had an erythrocyte mutant frequency of 4.211 × 10-6 (95% CI 1.39-5.16) mutants per million (p = 0.0052). A cut-off value of 4.7 mutants per million provided an AUROC of 0.7595 with a sensitivity of 70% and specificity of 78.57%. A secondary measure of DNA damage in an alternative blood cell population also showed an increase in peripheral lymphocytes using the cytokinesis-block micronucleus assay (p = 0.0164) (AUROC = 0.77, sensitivity = 72.22%, specificity = 72.73%). The micronucleus frequency and PIG-A status show some potential as blood-based biomarkers of pancreatic cancer, but further investigations of these DNA damage tests are required to assess their utility in pancreatic cancer diagnosis.
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Affiliation(s)
- Lucy Nichols
- Swansea University Medical School, Swansea University, Singleton Park, Swansea, United Kingdom
| | - Rachel Lawrence
- Swansea University Medical School, Swansea University, Singleton Park, Swansea, United Kingdom
| | - Hasan Haboubi
- Swansea University Medical School, Swansea University, Singleton Park, Swansea, United Kingdom
| | - Bilal Al-Sarireh
- Department of Pancreato-biliary surgery, Morriston Hospital, Swansea, United Kingdom
| | - Shareen Doak
- Swansea University Medical School, Swansea University, Singleton Park, Swansea, United Kingdom
| | - Gareth Jenkins
- Swansea University Medical School, Swansea University, Singleton Park, Swansea, United Kingdom
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Gollapudi BB. Genotoxicity evaluation of orally administered styrene monomer in mice using comet, micronucleus, and Pig-a endpoints. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2023. [PMID: 37042435 DOI: 10.1002/em.22540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 04/07/2023] [Indexed: 06/19/2023]
Abstract
Male B6C3F1 mice were administered styrene monomer by oral gavage for 29 consecutive days at dose levels of 0, 75, 150, or 300 mg/kg/day. The highest dose level represented the maximum tolerated dose based on findings in a 28-day dose range-finding study, in which the bioavailability of orally administered styrene was also confirmed. The positive control group received ethyl nitrosourea (ENU; 51.7 mg/kg/day) on Study Days 1-3 and ethyl methanesulfonate (EMS; 150 mg/kg/day) on Study Days 27-29 by oral gavage. Approximately 3 h following the final dose, blood was collected to assess erythrocyte Pig-a mutant and micronucleus frequencies. DNA strand breakage was assessed in glandular stomach, duodenum, kidney, liver, and lung tissues using the alkaline comet assay. The %tail DNA for stomach, liver, lung, and kidney in the comet assay among the styrene-treated groups was neither significantly different from the respective vehicle controls nor was there any dose-related increasing trend in any of the tissues; results for duodenum were interpreted to be inconclusive because of technical issues. The Pig-a and micronucleus frequencies among styrene-treated groups also did not show significant increases relative to the vehicle controls and there was also no evidence for a dose-related increasing trend. Thus, orally administered styrene did not induce DNA damage, mutagenesis, or clastogenesis/aneugenesis in these Organization of Economic Co-operation and Development test guideline-compliant genotoxicity studies. Data from these studies can contribute to the overall assessment of genotoxic hazard and risk posed to humans potentially exposed to styrene.
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Torous DK, Avlasevich S, Bemis JC, Howard T, Ware RE, Fung C, Chen Y, Sahsrabudhe D, MacGregor JT, Dertinger SD. Lack of hydroxyurea-associated mutagenesis in pediatric sickle cell disease patients. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2023; 64:167-175. [PMID: 36841969 DOI: 10.1002/em.22536] [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: 12/08/2022] [Revised: 02/20/2023] [Accepted: 02/22/2023] [Indexed: 05/03/2023]
Abstract
Hydroxyurea is approved for treating children and adults with sickle cell anemia (SCA). Despite its proven efficacy, concerns remain about its mutagenic and carcinogenic potential that hamper its widespread use. Cell culture- and animal-based investigations indicate that hydroxyurea's genotoxic effects are due to indirect clastogenicity in select cell types when high dose and time thresholds are exceeded (reviewed by Ware & Dertinger, 2021). The current study extends these preclinical observations to pediatric patients receiving hydroxyurea for treatment of SCA. First, proof-of-principle experiments with testicular cancer patients exposed to a cisplatin-based regimen validated the ability of flow cytometric blood-based micronucleated reticulocyte (MN-RET) and PIG-A mutant reticulocyte (MUT RET) assays to detect clastogenicity and gene mutations, respectively. Second, these biomarkers were measured in a cross-sectional study with 26 SCA patients receiving hydroxyurea and 13 SCA patients without exposure. Finally, a prospective study was conducted with 10 SCA patients using pretreatment blood samples and after 6 or 12 months of therapy. Cancer patients exposed to cisplatin exhibited increased MN-RET within days of exposure, while the MUT RET endpoint required more time to reach maximal levels. In SCA patients, hydroxyurea induced MN-RET in both the cross-sectional and prospective studies. However, no evidence of PIG-A gene mutation was found in hydroxyurea-treated children, despite the fact that the two assays use the same rapidly-dividing, highly-exposed cell type. Collectively, these results reinforce the complementary nature of MN-RET and MUT RET biomarkers, and indicate that hydroxyurea can be clastogenic but was not mutagenic in young patients with SCA.
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Affiliation(s)
| | | | | | - Thad Howard
- Division of Hematology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Russell E Ware
- Division of Hematology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Chunkit Fung
- J.P. Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, New York, USA
| | - Yuhchyau Chen
- J.P. Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, New York, USA
| | - Deepak Sahsrabudhe
- J.P. Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, New York, USA
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Zhu X, Huo J, Zeng Z, Liu Y, Li R, Chen Y, Zhang L, Chen J. Determination of potential thresholds for N-ethyl-N-nitrosourea and ethyl methanesulfonate based on a multi-endpoint genotoxicity assessment platform in rats. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:85128-85142. [PMID: 35793016 PMCID: PMC9646607 DOI: 10.1007/s11356-022-21605-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 06/17/2022] [Indexed: 06/15/2023]
Abstract
The main goal of the study was to investigate the genotoxic response of N-ethyl-N-nitrosourea (ENU) and ethyl methanesulfonate (EMS) at low doses in a multi-endpoint genotoxicity assessment platform in rats and to derive potential thresholds and related metrics. Male Sprague-Dawley rats were treated by daily oral gavage for 28 consecutive days with ENU (0.25 ~ 8 mg/kg bw) and EMS (5 ~ 160 mg/kg bw), both with six closely spaced dose levels. Pig-a gene mutation assay, micronucleus test, and comet assay were performed in several timepoints. Then, the dose-response relationships were analyzed for possible points of departure (PoD) using the no observed genotoxic effect level and benchmark dose (BMD) protocols with different critical effect sizes (CES, 0.05, 0.1, 0.5, and 1SD). Overall, dose-dependent increases in all investigated endpoints were found for ENU and EMS. PoDs varied across genetic endpoints, timepoints, and statistical methods, and selecting an appropriate lower 95% confidence limit of BMD needs a comprehensive consideration of the mode of action of chemicals, the characteristics of tests, and the model fitting methods. Under the experimental conditions, the PoDs of ENU and EMS were 0.0036 mg/kg bw and 1.7 mg/kg bw, respectively.
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Affiliation(s)
- Xuejiao Zhu
- Department of Nutrition, Food Safety and Toxicology, West China School of Public Health, Sichuan University, Chengdu, Sichuan, China
- West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Jiao Huo
- Department of Nutrition and Food Safety, Chongqing Center for Disease Control and Prevention, Chongqing, China
- Department of Nutrition, Food Safety and Toxicology, West China School of Public Health, Sichuan University, Chengdu, Sichuan, China
| | - Zhu Zeng
- Department of Nutrition, Food Safety and Toxicology, West China School of Public Health, Sichuan University, Chengdu, Sichuan, China
- Chengdu Fifth People's Hospital, Chengdu, Sichuan, China
| | - Yunjie Liu
- Department of Nutrition, Food Safety and Toxicology, West China School of Public Health, Sichuan University, Chengdu, Sichuan, China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Ruirui Li
- Department of Nutrition, Food Safety and Toxicology, West China School of Public Health, Sichuan University, Chengdu, Sichuan, China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Yiyi Chen
- Department of Nutrition, Food Safety and Toxicology, West China School of Public Health, Sichuan University, Chengdu, Sichuan, China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Lishi Zhang
- Department of Nutrition, Food Safety and Toxicology, West China School of Public Health, Sichuan University, Chengdu, Sichuan, China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Jinyao Chen
- Department of Nutrition, Food Safety and Toxicology, West China School of Public Health, Sichuan University, Chengdu, Sichuan, China.
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China.
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12
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Genotoxicity evaluation of a valsartan-related complex N-nitroso-impurity. Regul Toxicol Pharmacol 2022; 134:105245. [PMID: 35988810 DOI: 10.1016/j.yrtph.2022.105245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 07/25/2022] [Accepted: 08/02/2022] [Indexed: 11/20/2022]
Abstract
Recently, the formation of genotoxic and carcinogenic N-nitrosamines impurities during drug manufacturing of tetrazole-containing angiotensin-II blockers has been described. However, drug-related (complex) nitrosamines may also be generated under certain conditions, i.e., through nitrosation of vulnerable amines in drug substances in the presence of nitrite. An investigation of valsartan drug substance showed that a complex API-related N-nitrosamine chemically designated as (S)-2-(((2'-(1H-tetrazol-5-yl)-[1,1'-biphenyl]-4-yl)methyl)(nitroso)amino)-3-methylbutanoic acid (named 181-14) may be generated. 181-14 was shown to be devoid of a mutagenic potential in the Non-GLP Ames test. According to ICH M7 (R1) (2018), impurities that are not mutagenic in the Ames test would be considered Class 5 impurities and limited according to ICH Q3A (R2) and B (R2) (2006) guidelines. However, certain regulatory authorities raised the concern that the Ames test may not be sufficiently sensitive to detect a mutagenic potential of nitrosamines and requested a confirmatory in vivo study using a transgenic animal genotoxicity model. Our data show that 181-14 was not mutagenic in the transgenic gene mutation assay in MutaTMMice. The data support the conclusion that the Ames test is an adequate and sensitive test system to assess a mutagenic potential of nitrosamines.
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13
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Miao Y, Wang D, Chen Y, Zhu X, Tang X, Zhang J, Zhang L, Chen J. General toxicity and genotoxicity of alternariol: a novel 28-day multi-endpoint assessment in male Sprague-Dawley rats. Mycotoxin Res 2022; 38:231-241. [PMID: 35913592 DOI: 10.1007/s12550-022-00466-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 07/11/2022] [Accepted: 07/25/2022] [Indexed: 10/16/2022]
Abstract
Alternariol (AOH) is one of the toxins of Alternaria, and it has been widely detected in a variety of foods. It has been reported to be cytotoxic, dermally toxic, genotoxic, and potentially carcinogenic in vitro. However, in vivo toxicity data are lacking. This study used a novel in vivo 28-day multi-endpoint (Pig-a assay + micronucleus test + comet assay) genotoxicity evaluation system to evaluate the general toxicity and genotoxicity of AOH. A total of 42 male Sprague-Dawley rats were randomly distributed into three AOH-treated groups (5.51, 10.03, and 22.05 µg/kg bw), one AOH high-dose recovery group (AOH-HR, 22.05 µg/kg bw), one positive control group (N-ethyl-N-nitrosourea, 40 mg/kg bw), and two vehicle control groups (corn oil and PBS). Treatments were administered by oral gavage for 28 consecutive days. Histopathological lesions were observed in the liver, kidney, and spleen in all AOH-treated groups. No statistical difference was found in each genotoxicity index within 28 days in the AOH-treated groups compared with those in the corn oil group. On day 42, in the AOH-HR group, the rate of Pig-a mutant phenotype reticulocytes (RETCD59-) significantly increased. On day 56, both RETCD59- and the rate of Pig-a mutant phenotype erythrocytes (RBCCD59-) were significantly reduced. These findings indicated that AOH might cumulatively induce genetic mutations.
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Affiliation(s)
- Yeqiu Miao
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China.,Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Dongxia Wang
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China.,Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Yiyi Chen
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Xia Zhu
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China.,Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Xinyao Tang
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China.,Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Jing Zhang
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China.,Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Lishi Zhang
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China.,Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Jinyao Chen
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China. .,Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China.
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14
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Zeng Z, Huo J, Zhu X, Liu Y, Li R, Chen Y, Zhang L, Chen J. Characterization of benzo[ a]pyrene and colchicine based on an in vivo repeat-dosing multi-endpoint genotoxicity quantitative assessment platform. Mutagenesis 2022; 37:213-225. [PMID: 35869703 DOI: 10.1093/mutage/geac012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 07/06/2022] [Indexed: 11/13/2022] Open
Abstract
Abstract
Two prototypical genotoxicants, benzo[a]pyrene (B[a]P) and colchicine (COL), were selected as model compounds to deduce their quantitative genotoxic dose–response relationship at low doses in a multi-endpoint genotoxicity assessment platform. Male Sprague-Dawley rats were treated with B[a]P (2.5–80 mg/kg bw/day) and COL (0.125–2 mg/kg bw/day) daily for 28 days. The parameters included were as follows: comet assay in the peripheral blood and liver, Pig-a gene mutation assay in the peripheral blood, and micronucleus test in the peripheral blood and bone marrow. A significant increase was observed in Pig-a mutant frequency in peripheral blood for B[a]P (started at 40 mg/kg bw/day on Day 14, started at 20 mg/kg bw/day on Day 28), whereas no statistical difference for COL was observed. Micronucleus frequency in reticulocytes of the peripheral blood and bone marrow increased significantly for B[a]P (80 mg/kg bw/day on Day 4, started at 20 mg/kg bw/day on Days 14 and 28 in the blood; started at 20 mg/kg bw/day on Day 28 in the bone marrow) and COL (started at 2 mg/kg bw/day on Day 14, 1 mg/kg bw/day on Day 28 in the blood; started at 1 mg/kg bw/day on Day 28 in the bone marrow). No statistical variation was found in indexes of comet assay at all time points for B[a]P and COL in the peripheral blood and liver. The dose–response relationships of Pig-a and micronucleus test data were analyzed for possible point of departures using three quantitative approaches, i.e., the benchmark dose, breakpoint dose, and no observed genotoxic effect level. The practical thresholds of the genotoxicity of B[a]P and COL estimated in this study were 0.122 and 0.0431 mg/kg bw/day, respectively, and our results also provided distinct genotoxic mode of action of the two chemicals.
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Affiliation(s)
- Zhu Zeng
- Department of Clinical Nutrition, Chengdu Fifth People’s Hospital , Chengdu, Sichuan , China
- Department of Nutrition, Food Safety and Toxicology, West China School of Public Health, Sichuan University , Chengdu, Sichuan , China
| | - Jiao Huo
- Department of Nutrition, Food Safety and Toxicology, West China School of Public Health, Sichuan University , Chengdu, Sichuan , China
- Department of Nutrition and Food Safety, Chongqing Center for Disease Control and Prevention , Chongqing , China
| | - Xuejiao Zhu
- Department of Nutrition, Food Safety and Toxicology, West China School of Public Health, Sichuan University , Chengdu, Sichuan , China
- West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University , Chengdu, Sichuan , China
| | - Yunjie Liu
- Department of Nutrition, Food Safety and Toxicology, West China School of Public Health, Sichuan University , Chengdu, Sichuan , China
- West China School of Public Health, Sichuan University , Chengdu, Sichuan , China
| | - Ruirui Li
- Department of Nutrition, Food Safety and Toxicology, West China School of Public Health, Sichuan University , Chengdu, Sichuan , China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province , Chengdu, Sichuan , China
| | - Yiyi Chen
- Department of Nutrition, Food Safety and Toxicology, West China School of Public Health, Sichuan University , Chengdu, Sichuan , China
- Infections Disease Prevention and Immunization Program Office, ChengHua Center for Disease Control and Prevention , Chengdu, Sichuan , China
| | - Lishi Zhang
- Department of Nutrition, Food Safety and Toxicology, West China School of Public Health, Sichuan University , Chengdu, Sichuan , China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province , Chengdu, Sichuan , China
| | - Jinyao Chen
- Department of Nutrition, Food Safety and Toxicology, West China School of Public Health, Sichuan University , Chengdu, Sichuan , China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province , Chengdu, Sichuan , China
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15
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Cho E, Allemang A, Audebert M, Chauhan V, Dertinger S, Hendriks G, Luijten M, Marchetti F, Minocherhomji S, Pfuhler S, Roberts DJ, Trenz K, Yauk CL. AOP report: Development of an adverse outcome pathway for oxidative DNA damage leading to mutations and chromosomal aberrations. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2022; 63:118-134. [PMID: 35315142 PMCID: PMC9322445 DOI: 10.1002/em.22479] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 03/18/2022] [Indexed: 05/22/2023]
Abstract
The Genetic Toxicology Technical Committee (GTTC) of the Health and Environmental Sciences Institute (HESI) is developing adverse outcome pathways (AOPs) that describe modes of action leading to potentially heritable genomic damage. The goal was to enhance the use of mechanistic information in genotoxicity assessment by building empirical support for the relationships between relevant molecular initiating events (MIEs) and regulatory endpoints in genetic toxicology. Herein, we present an AOP network that links oxidative DNA damage to two adverse outcomes (AOs): mutations and chromosomal aberrations. We collected empirical evidence from the literature to evaluate the key event relationships between the MIE and the AOs, and assessed the weight of evidence using the modified Bradford-Hill criteria for causality. Oxidative DNA damage is constantly induced and repaired in cells given the ubiquitous presence of reactive oxygen species and free radicals. However, xenobiotic exposures may increase damage above baseline levels through a variety of mechanisms and overwhelm DNA repair and endogenous antioxidant capacity. Unrepaired oxidative DNA base damage can lead to base substitutions during replication and, along with repair intermediates, can also cause DNA strand breaks that can lead to mutations and chromosomal aberrations if not repaired adequately. This AOP network identifies knowledge gaps that could be filled by targeted studies designed to better define the quantitative relationships between key events, which could be leveraged for quantitative chemical safety assessment. We anticipate that this AOP network will provide the building blocks for additional genotoxicity-associated AOPs and aid in designing novel integrated testing approaches for genotoxicity.
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Affiliation(s)
- Eunnara Cho
- Environmental Health Science and Research BureauHealth CanadaOttawaOntarioCanada
- Department of BiologyCarleton UniversityOttawaOntarioCanada
| | | | | | - Vinita Chauhan
- Consumer and Clinical Radiation Protection BureauHealth CanadaOttawaOntarioCanada
| | | | | | - Mirjam Luijten
- Centre for Health ProtectionNational Institute for Public Health and the Environment (RIVM)BilthovenThe Netherlands
| | - Francesco Marchetti
- Environmental Health Science and Research BureauHealth CanadaOttawaOntarioCanada
- Department of BiologyCarleton UniversityOttawaOntarioCanada
| | - Sheroy Minocherhomji
- Amgen Research, Translational Safety and Bioanalytical SciencesAmgen Inc.Thousand OaksCaliforniaUSA
| | | | | | | | - Carole L. Yauk
- Environmental Health Science and Research BureauHealth CanadaOttawaOntarioCanada
- Department of BiologyCarleton UniversityOttawaOntarioCanada
- Department of BiologyUniversity of OttawaOttawaOntarioCanada
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16
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Zhu X, Chen Y, Tang X, Wang D, Miao Y, Zhang J, Li R, Zhang L, Chen J. General toxicity and genotoxicity of
Altertoxin
I: a novel 28‐Day multi‐endpoint assessment in male Sprague Dawley rats. J Appl Toxicol 2022; 42:1310-1322. [PMID: 35128692 DOI: 10.1002/jat.4297] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 01/29/2022] [Accepted: 01/29/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Xia Zhu
- West China School of Public Health and West China Fourth Hospital Sichuan University Chengdu China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province Chengdu Sichuan China
| | - Yiyi Chen
- West China School of Public Health and West China Fourth Hospital Sichuan University Chengdu China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province Chengdu Sichuan China
| | - Xinyao Tang
- West China School of Public Health and West China Fourth Hospital Sichuan University Chengdu China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province Chengdu Sichuan China
| | - Dongxia Wang
- West China School of Public Health and West China Fourth Hospital Sichuan University Chengdu China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province Chengdu Sichuan China
| | - Yeqiu Miao
- West China School of Public Health and West China Fourth Hospital Sichuan University Chengdu China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province Chengdu Sichuan China
| | - Jing Zhang
- West China School of Public Health and West China Fourth Hospital Sichuan University Chengdu China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province Chengdu Sichuan China
| | - Ruirui Li
- West China School of Public Health and West China Fourth Hospital Sichuan University Chengdu China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province Chengdu Sichuan China
| | - Lishi Zhang
- West China School of Public Health and West China Fourth Hospital Sichuan University Chengdu China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province Chengdu Sichuan China
| | - Jinyao Chen
- West China School of Public Health and West China Fourth Hospital Sichuan University Chengdu China
- Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province Chengdu Sichuan China
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17
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Platel A, Dusautoir R, Kervoaze G, Dourdin G, Gateau E, Talahari S, Huot L, Simar S, Ollivier A, Laine W, Kluza J, Gosset P, Garçon G, Anthérieu S, Guidice JML, Nesslany F. Comparison of the in vivo genotoxicity of electronic and conventional cigarettes aerosols after subacute, subchronic and chronic exposures. JOURNAL OF HAZARDOUS MATERIALS 2022; 423:127246. [PMID: 34844363 DOI: 10.1016/j.jhazmat.2021.127246] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 09/01/2021] [Accepted: 09/13/2021] [Indexed: 06/13/2023]
Abstract
Tobacco smoking is classified as a human carcinogen. A wide variety of new products, in particular electronic cigarettes (e-cigs), have recently appeared on the market as an alternative to smoking. Although the in vitro toxicity of e-cigs is relatively well known, there is currently a lack of data on their long-term health effects. In this context, the aim of our study was to compare, on a mouse model and using a nose-only exposure system, the in vivo genotoxic and mutagenic potential of e-cig aerosols tested at two power settings (18 W and 30 W) and conventional cigarette (3R4F) smoke. The standard comet assay, micronucleus test and Pig-a gene mutation assay were performed after subacute (4 days), subchronic (3 months) and chronic (6 months) exposure. The generation of oxidative stress was also assessed by measuring the 8-hydroxy-2'-deoxyguanosine and by using the hOGG1-modified comet assay. Our results show that only the high-power e-cig and the 3R4F cigarette induced oxidative DNA damage in the lung and the liver of exposed mice. In return, no significant increase in chromosomal aberrations or gene mutations were noted whatever the type of product. This study demonstrates that e-cigs, at high-power setting, should be considered, contrary to popular belief, as hazardous products in terms of genotoxicity in mouse model.
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Affiliation(s)
- Anne Platel
- CHU Lille, Institut Pasteur de Lille, ULR 4483-IMPact de l'Environnement Chimique sur la Santé (IMPECS), Univ. Lille, Lille, France.
| | - Romain Dusautoir
- CHU Lille, Institut Pasteur de Lille, ULR 4483-IMPact de l'Environnement Chimique sur la Santé (IMPECS), Univ. Lille, Lille, France.
| | - Gwenola Kervoaze
- University of Lille, CNRS UMR9017, Inserm U1019, CHRU Lille, Institut Pasteur de Lille, CIIL - Center for Infection and Immunity of Lille, OpInfIELD, France.
| | - Gonzague Dourdin
- CHU Lille, Institut Pasteur de Lille, ULR 4483-IMPact de l'Environnement Chimique sur la Santé (IMPECS), Univ. Lille, Lille, France.
| | - Eulalie Gateau
- CHU Lille, Institut Pasteur de Lille, ULR 4483-IMPact de l'Environnement Chimique sur la Santé (IMPECS), Univ. Lille, Lille, France.
| | - Smaïl Talahari
- CHU Lille, Institut Pasteur de Lille, ULR 4483-IMPact de l'Environnement Chimique sur la Santé (IMPECS), Univ. Lille, Lille, France.
| | - Ludovic Huot
- CHU Lille, Institut Pasteur de Lille, ULR 4483-IMPact de l'Environnement Chimique sur la Santé (IMPECS), Univ. Lille, Lille, France.
| | - Sophie Simar
- CHU Lille, Institut Pasteur de Lille, ULR 4483-IMPact de l'Environnement Chimique sur la Santé (IMPECS), Univ. Lille, Lille, France.
| | - Anaïs Ollivier
- University of Lille, CNRS UMR9017, Inserm U1019, CHRU Lille, Institut Pasteur de Lille, CIIL - Center for Infection and Immunity of Lille, OpInfIELD, France.
| | - William Laine
- UMR 9020-UMR-S 1277-Canther-Cancer Heterogeneity, Plasticity and Resistance to Therapies, Institut de Recherche contre le Cancer de Lille, University Lille, CNRS, Inserm, CHU Lille, F-59000 Lille, France.
| | - Jérôme Kluza
- UMR 9020-UMR-S 1277-Canther-Cancer Heterogeneity, Plasticity and Resistance to Therapies, Institut de Recherche contre le Cancer de Lille, University Lille, CNRS, Inserm, CHU Lille, F-59000 Lille, France.
| | - Philippe Gosset
- University of Lille, CNRS UMR9017, Inserm U1019, CHRU Lille, Institut Pasteur de Lille, CIIL - Center for Infection and Immunity of Lille, OpInfIELD, France.
| | - Guillaume Garçon
- CHU Lille, Institut Pasteur de Lille, ULR 4483-IMPact de l'Environnement Chimique sur la Santé (IMPECS), Univ. Lille, Lille, France.
| | - Sébastien Anthérieu
- CHU Lille, Institut Pasteur de Lille, ULR 4483-IMPact de l'Environnement Chimique sur la Santé (IMPECS), Univ. Lille, Lille, France.
| | - Jean-Marc Lo Guidice
- CHU Lille, Institut Pasteur de Lille, ULR 4483-IMPact de l'Environnement Chimique sur la Santé (IMPECS), Univ. Lille, Lille, France.
| | - Fabrice Nesslany
- CHU Lille, Institut Pasteur de Lille, ULR 4483-IMPact de l'Environnement Chimique sur la Santé (IMPECS), Univ. Lille, Lille, France.
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18
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Caraco Y, Crofoot GE, Moncada PA, Galustyan AN, Musungaie DB, Payne B, Kovalchuk E, Gonzalez A, Brown ML, Williams-Diaz A, Gao W, Strizki JM, Grobler J, Du J, Assaid CA, Paschke A, Butterton JR, Johnson MG, De Anda C. Phase 2/3 Trial of Molnupiravir for Treatment of Covid-19 in Nonhospitalized Adults. NEJM EVIDENCE 2022; 1:EVIDoa2100043. [PMID: 38319179 DOI: 10.1056/evidoa2100043] [Citation(s) in RCA: 51] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
BACKGROUND: Safe and effective oral treatments are needed to improve clinical outcomes for nonhospitalized patients with Covid-19. Molnupiravir is an orally administered, small-molecule ribonucleoside prodrug shown to inhibit replication of severe acute respiratory syndrome coronavirus 2 in vitro and in animal models. METHODS: MOVe-OUT is an ongoing, phase 2/3, randomized, placebo-controlled, double-blind study evaluating the safety, efficacy, and pharmacokinetics of molnupiravir in nonhospitalized adults. In the phase 2 component, participants had mild or moderate, laboratory-confirmed Covid-19 with sign/symptom onset up to (and including) 7 days before randomization. Participants were randomly assigned 1:1:1:1 to receive 200, 400, or 800 mg of molnupiravir or placebo twice daily for 5 days, stratified by time since sign/symptom onset and by being at increased risk for severe illness from Covid-19. The primary efficacy end point was the proportion of participants who were hospitalized and/or died through day 29. RESULTS: The phase 2 component randomly assigned 302 participants to treatment; baseline characteristics were comparable across treatment groups. Molnupiravir had no apparent dose-related effect on adverse events, and no clinically meaningful abnormalities in laboratory test results were observed in relation to dose or treatment. Eleven participants were hospitalized or died through day 29. Of 225 participants in the combined molnupiravir group, 7 (3.1%) were hospitalized or died, compared with 4 of 74 participants (5.4%) in the placebo group. Subgroup analyses suggested lower incidences of hospitalization and/or death in the molnupiravir versus placebo groups in participants older than 60 years of age, those with increased risk for severe illness, those with symptom onset up to (and including) 5 days before randomization, and those with both symptom onset up to (and including) 5 days before randomization and increased risk for severe illness. CONCLUSIONS: These interim study results support further evaluation of molnupiravir as a potential treatment to reduce hospitalizations and/or death in nonhospitalized patients with Covid-19. (Funded by Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc.; ClinicalTrials.gov number, NCT04575597.)
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Affiliation(s)
- Yoseph Caraco
- Clinical Pharmacology Unit, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | | | - Pablo Andres Moncada
- Department of Internal Medicine, Infectious Disease Service, Fundación Valle del Lili, Cali, Colombia
| | - Anna Nikolaevna Galustyan
- Saint Petersburg State Pediatric Medical University, Saint Petersburg, Russia
- Strategic Medical System LLC, Saint Petersburg, Russia
| | | | - Brendan Payne
- Departments of Infectious Diseases and Medical Virology, Newcastle upon Tyne Hospitals, Newcastle upon Tyne, UK
| | | | | | | | | | - Wei Gao
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, NJ
| | - Julie M Strizki
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, NJ
| | - Jay Grobler
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, NJ
| | - Jiejun Du
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, NJ
| | | | - Amanda Paschke
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, NJ
| | | | | | - Carisa De Anda
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, NJ
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19
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Waters MD, Warren S, Hughes C, Lewis P, Zhang F. Human genetic risk of treatment with antiviral nucleoside analog drugs that induce lethal mutagenesis: The special case of molnupiravir. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2022; 63:37-63. [PMID: 35023215 DOI: 10.1002/em.22471] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 12/28/2021] [Accepted: 01/08/2022] [Indexed: 06/14/2023]
Abstract
This review considers antiviral nucleoside analog drugs, including ribavirin, favipiravir, and molnupiravir, which induce genome error catastrophe in SARS-CoV or SARS-CoV-2 via lethal mutagenesis as a mode of action. In vitro data indicate that molnupiravir may be 100 times more potent as an antiviral agent than ribavirin or favipiravir. Molnupiravir has recently demonstrated efficacy in a phase 3 clinical trial. Because of its anticipated global use, its relative potency, and the reported in vitro "host" cell mutagenicity of its active principle, β-d-N4-hydroxycytidine, we have reviewed the development of molnupiravir and its genotoxicity safety evaluation, as well as the genotoxicity profiles of three congeners, that is, ribavirin, favipiravir, and 5-(2-chloroethyl)-2'-deoxyuridine. We consider the potential genetic risks of molnupiravir on the basis of all available information and focus on the need for additional human genotoxicity data and follow-up in patients treated with molnupiravir and similar drugs. Such human data are especially relevant for antiviral NAs that have the potential of permanently modifying the genomes of treated patients and/or causing human teratogenicity or embryotoxicity. We conclude that the results of preclinical genotoxicity studies and phase 1 human clinical safety, tolerability, and pharmacokinetics are critical components of drug safety assessments and sentinels of unanticipated adverse health effects. We provide our rationale for performing more thorough genotoxicity testing prior to and within phase 1 clinical trials, including human PIG-A and error corrected next generation sequencing (duplex sequencing) studies in DNA and mitochondrial DNA of patients treated with antiviral NAs that induce genome error catastrophe via lethal mutagenesis.
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Affiliation(s)
- Michael D Waters
- Michael Waters Consulting USA, Hillsborough, North Carolina, USA
| | | | - Claude Hughes
- Duke University Medical Center, Durham, North Carolina, USA
| | | | - Fengyu Zhang
- Global Clinical and Translational Research Institute, Bethesda, Maryland, USA
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20
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Cao Y, Xi J, You X, Liu W, Luan Y. Dose-response genotoxicity of triclosan in mice: an estimate of acceptable daily intake based on organ toxicity. Toxicol Res (Camb) 2021; 10:1153-1161. [PMID: 34956618 PMCID: PMC8692727 DOI: 10.1093/toxres/tfab098] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/23/2021] [Accepted: 10/10/2021] [Indexed: 11/13/2022] Open
Abstract
Triclosan (TCS) is widely used and it bioaccumulates in humans. We found that TCS induced DNA damage in TK6 cell in our previous work. Herein, we performed a pilot assay of the TK6 cell/TK gene (TK+/-) mutation assay without metabolic activation for 24 h and found that TCS significantly induced mutation frequency. We further investigated the dose-response toxicity and genotoxicity of TCS. We combined the newly developed Pig-a gene mutation assay with bone marrow micronucleus (MN) test in a 19-day short-term study. ICR mice were administered orally with TCS at six dose levels from 0 to1000 mg/kg/day. We quantitatively assessed the dose-response relationships for the Pig-a assay, MN test, and organ coefficient data for possible points of departure (PoDs) by estimating the benchmark dose using PROAST software. We did not observe elevated Pig-a mutant frequency or MN frequency in TCS-treated mice. But a dose-dependent and statistically significant increase in liver organ coefficient data was observed. The PoD and acceptable daily intake based on organ toxicity were further developed and no greater than 1.82 and 0.00182 mg/kg/day, respectively, indicating that the toxicity of TCS may has been underestimated in previous studies and greater attention should be paid to low-level TCS exposure.
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Affiliation(s)
- Yiyi Cao
- School of Public Health, Shanghai Jiaotong University School of Medicine, Shanghai 200025, People’s Republic of China
| | - Jing Xi
- School of Public Health, Shanghai Jiaotong University School of Medicine, Shanghai 200025, People’s Republic of China
| | - Xinyue You
- School of Public Health, Shanghai Jiaotong University School of Medicine, Shanghai 200025, People’s Republic of China
| | - Weiying Liu
- School of Public Health, Shanghai Jiaotong University School of Medicine, Shanghai 200025, People’s Republic of China
| | - Yang Luan
- School of Public Health, Shanghai Jiaotong University School of Medicine, Shanghai 200025, People’s Republic of China
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21
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Martini C, Liu YF, Gong H, Sayers N, Segura G, Fostel J. CEBS update: curated toxicology database with enhanced tools for data integration. Nucleic Acids Res 2021; 50:D1156-D1163. [PMID: 34751388 DOI: 10.1093/nar/gkab981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 10/05/2021] [Accepted: 11/01/2021] [Indexed: 11/14/2022] Open
Abstract
The Chemical Effects in Biological Systems database (CEBS) contains extensive toxicology study results and metadata from the Division of the National Toxicology Program (NTP) and other studies of environmental health interest. This resource grants public access to search and collate data from over 10 250 studies for 12 750 test articles (chemicals, environmental agents). CEBS has made considerable strides over the last 5 years to integrate growing internal data repositories into data warehouses and data marts to better serve the public with high quality curated datasets. This effort includes harmonizing legacy terms and metadata to current standards, mapping test articles to external identifiers, and aligning terms to OBO (Open Biological and Biomedical Ontology) Foundry ontologies. The data are made available through the CEBS Homepage (https://cebs.niehs.nih.gov/cebs/), guided search applications, flat files on FTP (file transfer protocol), and APIs (application programming interface) for user access and to provide a bridge for computational tools. The user interface is intuitive with a single search bar to query keywords related to study metadata, publications, and data availability. Results are consolidated to single pages for each test article with NTP conclusions, publications, individual studies, data collections, and links to related test articles and projects available together.
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Affiliation(s)
- Cari Martini
- ASRC Federal, 430 Davis Dr., Suite 400, Morrisville, NC 27560, USA
| | - Ying Frances Liu
- ASRC Federal, 430 Davis Dr., Suite 400, Morrisville, NC 27560, USA
| | - Hui Gong
- ASRC Federal, 430 Davis Dr., Suite 400, Morrisville, NC 27560, USA
| | - Nicole Sayers
- ASRC Federal, 430 Davis Dr., Suite 400, Morrisville, NC 27560, USA
| | - German Segura
- ASRC Federal, 430 Davis Dr., Suite 400, Morrisville, NC 27560, USA
| | - Jennifer Fostel
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, PO Box 12233, Research Triangle Park, NC 27709, USA
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22
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Tice RR, Bassan A, Amberg A, Anger LT, Beal MA, Bellion P, Benigni R, Birmingham J, Brigo A, Bringezu F, Ceriani L, Crooks I, Cross K, Elespuru R, Faulkner DM, Fortin MC, Fowler P, Frericks M, Gerets HHJ, Jahnke GD, Jones DR, Kruhlak NL, Lo Piparo E, Lopez-Belmonte J, Luniwal A, Luu A, Madia F, Manganelli S, Manickam B, Mestres J, Mihalchik-Burhans AL, Neilson L, Pandiri A, Pavan M, Rider CV, Rooney JP, Trejo-Martin A, Watanabe-Sailor KH, White AT, Woolley D, Myatt GJ. In Silico Approaches In Carcinogenicity Hazard Assessment: Current Status and Future Needs. COMPUTATIONAL TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2021; 20. [PMID: 35368437 DOI: 10.1016/j.comtox.2021.100191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Historically, identifying carcinogens has relied primarily on tumor studies in rodents, which require enormous resources in both money and time. In silico models have been developed for predicting rodent carcinogens but have not yet found general regulatory acceptance, in part due to the lack of a generally accepted protocol for performing such an assessment as well as limitations in predictive performance and scope. There remains a need for additional, improved in silico carcinogenicity models, especially ones that are more human-relevant, for use in research and regulatory decision-making. As part of an international effort to develop in silico toxicological protocols, a consortium of toxicologists, computational scientists, and regulatory scientists across several industries and governmental agencies evaluated the extent to which in silico models exist for each of the recently defined 10 key characteristics (KCs) of carcinogens. This position paper summarizes the current status of in silico tools for the assessment of each KC and identifies the data gaps that need to be addressed before a comprehensive in silico carcinogenicity protocol can be developed for regulatory use.
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Affiliation(s)
- Raymond R Tice
- RTice Consulting, Hillsborough, North Carolina, 27278, USA
| | | | - Alexander Amberg
- Sanofi Preclinical Safety, Industriepark Höchst, 65926 Frankfurt, Germany
| | - Lennart T Anger
- Genentech, Inc., South San Francisco, California, 94080, USA
| | - Marc A Beal
- Healthy Environments and Consumer Safety Branch, Health Canada, Government of Canada, Ottawa, Ontario, Canada K1A 0K9
| | | | | | - Jeffrey Birmingham
- GlaxoSmithKline, David Jack Centre for R&D, Ware, Hertfordshire, SG12 0DP, United Kingdom
| | - Alessandro Brigo
- Roche Pharmaceutical Research & Early Development, Pharmaceutical Sciences, Roche Innovation, Center Basel, F. Hoffmann-La Roche Ltd, CH-4070, Basel, Switzerland
| | | | - Lidia Ceriani
- Humane Society International, 1000 Brussels, Belgium
| | - Ian Crooks
- British American Tobacco (Investments) Ltd, GR&D Centre, Southampton, SO15 8TL, United Kingdom
| | | | - Rosalie Elespuru
- Food and Drug Administration, Center for Devices and Radiological Health, Silver Spring, Maryland, 20993, USA
| | - David M Faulkner
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Marie C Fortin
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, New Jersey, 08855, USA
| | - Paul Fowler
- FSTox Consulting (Genetic Toxicology), Northamptonshire, United Kingdom
| | | | | | - Gloria D Jahnke
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, 27709, USA
| | | | - Naomi L Kruhlak
- Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland, 20993, USA
| | - Elena Lo Piparo
- Chemical Food Safety Group, Nestlé Research, CH-1000 Lausanne 26, Switzerland
| | - Juan Lopez-Belmonte
- Cuts Ice Ltd Chemical Food Safety Group, Nestlé Research, CH-1000 Lausanne 26, Switzerland
| | - Amarjit Luniwal
- North American Science Associates (NAMSA) Inc., Minneapolis, Minnesota, 55426, USA
| | - Alice Luu
- Healthy Environments and Consumer Safety Branch, Health Canada, Government of Canada, Ottawa, Ontario, Canada K1A 0K9
| | - Federica Madia
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Serena Manganelli
- Chemical Food Safety Group, Nestlé Research, CH-1000 Lausanne 26, Switzerland
| | | | - Jordi Mestres
- IMIM Institut Hospital Del Mar d'Investigacions Mèdiques and Universitat Pompeu Fabra, Doctor Aiguader 88, Parc de Recerca Biomèdica, 08003 Barcelona, Spain; and Chemotargets SL, Baldiri Reixac 4, Parc Científic de Barcelona, 08028, Barcelona, Spain
| | | | - Louise Neilson
- Broughton Nicotine Services, Oak Tree House, Earby, Lancashire, BB18 6JZ United Kingdom
| | - Arun Pandiri
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, 27709, USA
| | | | - Cynthia V Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, 27709, USA
| | - John P Rooney
- Integrated Laboratory Systems, LLC., Morrisville, North Carolina, 27560, USA
| | | | - Karen H Watanabe-Sailor
- School of Mathematical and Natural Sciences, Arizona State University, West Campus, Glendale, Arizona, 85306, USA
| | - Angela T White
- GlaxoSmithKline, David Jack Centre for R&D, Ware, Hertfordshire, SG12 0DP, United Kingdom
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23
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Chen R, You X, Cao Y, Masumura K, Ando T, Hamada S, Horibata K, Wan J, Xi J, Zhang X, Honma M, Luan Y. Benchmark dose analysis of multiple genotoxicity endpoints in gpt delta mice exposed to aristolochic acid I. Mutagenesis 2021; 36:87-94. [PMID: 33367723 DOI: 10.1093/mutage/geaa034] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 11/24/2020] [Indexed: 11/12/2022] Open
Abstract
As the carcinogenic risk of herbs containing aristolochic acids (AAs) is a global health issue, quantitative evaluation of toxicity is needed for the regulatory decision-making and risk assessment of AAs. In this study, we selected AA I (AAI), the most abundant and representative compound in AAs, to treat transgenic gpt delta mice at six gradient doses ranging from 0.125 to 4 mg/kg/day for 28 days. AAI-DNA adduct frequencies and gpt gene mutation frequencies (MFs) in the kidney, as well as Pig-a gene MFs and micronucleated reticulocytes (MN-RETs) frequencies in peripheral blood, were monitored. The dose-response (DR) relationship data for these in vivo genotoxicity endpoints were quantitatively evaluated using an advanced benchmark dose (BMD) approach with different critical effect sizes (CESs; i.e., BMD5, BMD10, BMD50 and BMD100). The results showed that the AAI-DNA adduct frequencies, gpt MFs and the MN-RETs presented good DR relationship to the administrated doses, and the corresponding BMDL100 (the lower 90% confidence interval of the BMD100) values were 0.017, 0.509 and 3.9 mg/kg/day, respectively. No positive responses were observed in the Pig-a MFs due to bone marrow suppression caused by AAI. Overall, we quantitatively evaluated the genotoxicity of AAI at low doses for multiple endpoints for the first time. Comparisons of BMD100 values across different endpoints provide a basis for the risk assessment and regulatory decision-making of AAs and are also valuable for understanding the genotoxicity mechanism of AAs.
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Affiliation(s)
- Ruixue Chen
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xinyue You
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yiyi Cao
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Kenichi Masumura
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, Tonomachi, Kawasaki-ku, Kawasaki City, Kanagawa, Japan
| | - Tomoko Ando
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, Tonomachi, Kawasaki-ku, Kawasaki City, Kanagawa, Japan
| | - Shuichi Hamada
- Tokyo Laboratory BoZo Research Center Inc., Hanegi, Setagaya, Tokyo, Japan
| | - Katsuyoshi Horibata
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, Tonomachi, Kawasaki-ku, Kawasaki City, Kanagawa, Japan
| | - Jingjing Wan
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jing Xi
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xinyu Zhang
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Masamitsu Honma
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, Tonomachi, Kawasaki-ku, Kawasaki City, Kanagawa, Japan
| | - Yang Luan
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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24
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Elhajouji A, Hove TT, O'Connell O, Martus H, Dertinger SD. Pig-a gene mutation assay study design: critical assessment of 3- versus 28-day repeat-dose treatment schedules. Mutagenesis 2021; 35:349-358. [PMID: 32608486 DOI: 10.1093/mutage/geaa014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 05/27/2020] [Indexed: 11/12/2022] Open
Abstract
The in vivo Pig-a assay is being used in safety studies to evaluate the potential of chemicals to induce somatic cell gene mutations. Ongoing work is aimed at developing an Organisation for Economic Cooperation and Development (OECD) test guideline to support routine use for regulatory purposes (OECD project number 4.93). Among the details that will need to be articulated in an eventual guideline are recommended treatment and harvest schedules. With this in mind, experiments reported herein were performed with Wistar Han rats exposed to aristolochic acid I (AA), 1,3-propane sultone, chlorambucil, thiotepa or melphalan using each of two commonly used treatment schedules: 3 or 28 consecutive days. In the case of the 3-day studies, blood was collected for Pig-a analysis on days 15 or 16 and 29 or 30. For the 28-day studies blood was collected on day 29 or 30. The effect of treatment on mutant reticulocytes and mutant erythrocytes was evaluated with parametric pair-wise tests. While each of the five mutagens increased mutant phenotype cell frequencies irrespective of study design, statistical significance was consistently achieved at lower dose levels when the 28-day format was used (e.g. 2.75 vs 20 mg/kg/bw for AA). To more thoroughly investigate the dose-response relationships, benchmark dose (BMD) analyses were performed with PROAST software. These results corroborate the pair-wise testing results in that lower BMD values were obtained with the 28-day design. Finally, mutagenic potency, as measured by BMD analyses, most consistently correlated with the mutagens' tumorigenic dose 50 values when the lengthier treatment schedule was used. Collectively, these results suggest that both 3- and 28-day treatment schedules have merit in hazard identification-type studies. That being said, for the purpose of regulatory safety assessments, there are clear advantages to study designs that utilise protracted exposures.
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Affiliation(s)
- Azeddine Elhajouji
- Preclinical Safety, Novartis Institutes for Biomedical Research, Novartis Pharma AG, WKL-135.2.25, Basel, Switzerland
| | - Tamsanqa Tafara Hove
- Preclinical Safety, Novartis Institutes for Biomedical Research, Novartis Pharma AG, WKL-135.2.25, Basel, Switzerland
| | - Oliver O'Connell
- Preclinical Safety, Novartis Institutes for Biomedical Research, Novartis Pharma AG, WKL-135.2.25, Basel, Switzerland
| | - Hansjoerg Martus
- Preclinical Safety, Novartis Institutes for Biomedical Research, Novartis Pharma AG, WKL-135.2.25, Basel, Switzerland
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25
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Zhu X, Zeng Z, Chen Y, Li R, Tang X, Zhu X, Huo J, Liu Y, Zhang L, Chen J. Genotoxicity of three mycotoxin contaminants of rice: 28-day multi-endpoint assessment in rats. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2021; 867:503369. [PMID: 34266625 DOI: 10.1016/j.mrgentox.2021.503369] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 05/29/2021] [Accepted: 05/31/2021] [Indexed: 06/13/2023]
Abstract
Deoxynivalenol (DON), zearalenone (ZEN), and fumonisin B1 (FB1), as the main mycotoxins contaminating rice, often coexist in food. Thus, we have measured the genotoxicity of the three rice fungal contaminants, singly and in different combinations, with a 28-day multi-endpoint (Pig-a assay + in vivo micronucleus [MN] test + comet assay) genotoxicity platform. Male Sprague-Dawley rats received the agents orally via gavage for 28 consecutive days, before performing the abovementioned tests. Results indicated that low dose of a single mycotoxin did not show significant genotoxicity. However, some of these mycotoxins in combination induced significant genotoxicity in the peripheral blood and tissues, at sacrifice. In the peripheral blood, the binary combination of DON and FB1 significantly induced MN. In the liver, ZEN might aggravate the DNA-damaging effects of DON and FB1. Therefore, the genotoxicity of sub-chronic exposure to mycotoxins in combination cannot be ignored.
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Affiliation(s)
- Xia Zhu
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China; Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Zhu Zeng
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China; The Fifth People's Hospital of Chengdu, Chengdu, Sichuan, China
| | - Yiyi Chen
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China; Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Ruirui Li
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China; Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Xinyao Tang
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China; Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Xuejiao Zhu
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China; Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Jiao Huo
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China; Chongqing Center for Disease Control and Prevention, Chongqing, China
| | - Yunjie Liu
- Graduate Department, West China School of Public Health, Sichuan University, Chengdu, Sichuan, China
| | - Lishi Zhang
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China; Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China
| | - Jinyao Chen
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China; Food Safety Monitoring and Risk Assessment Key Laboratory of Sichuan Province, Chengdu, Sichuan, China.
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26
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Revollo JR, McKinzie PB, Robison TW, Dobrovolsky VN. Mutational signatures in T-lymphocytes of rats treated with N-propyl-N-nitrosourea and procarbazine. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2021; 62:350-363. [PMID: 34117657 DOI: 10.1002/em.22448] [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: 03/24/2021] [Revised: 05/12/2021] [Accepted: 06/09/2021] [Indexed: 06/12/2023]
Abstract
We have used whole genome sequencing (WGS) to determine mutational signatures induced in the T-cells of rats treated in vivo with N-propyl-N-nitrosourea (PNU) or procarbazine (PCZ). The signatures from the treated rats were different from the signature of background mutations. The main component of the spontaneous T-cell mutational signature was C➔T transition with all other single base substitutions evenly distributed. The PNU-induced mutational signature showed relatively equal contributions from C➔T and T➔C transitions, and T➔A transversions. The PCZ-induced signature was characterized by T➔C transitions, T➔A and, to a smaller extent, T➔G transversions. C➔G transversions were infrequent in either the PNU or PCZ signatures. WGS not only allowed mutational signature detection, but also measured quantitative responses to mutagen treatment: 10-40× increases in the number of mutations per clone were detected in T-cell clones from treated rats. The overall strand specificity of induced mutations for annotated rat genes was comparable to the strand specificity of mutations determined previously for the endogenous X-linked Pig-a gene. Our results provide valuable reference data for future applications of WGS in safety research and risk assessment.
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Affiliation(s)
- Javier R Revollo
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas, USA
| | - Page B McKinzie
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas, USA
| | - Timothy W Robison
- Division of Pulmonary, Allergy and Critical Care Products, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Vasily N Dobrovolsky
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas, USA
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27
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da Silva Junior FC, Felipe MBMC, Castro DEFD, Araújo SCDS, Sisenando HCN, Batistuzzo de Medeiros SR. A look beyond the priority: A systematic review of the genotoxic, mutagenic, and carcinogenic endpoints of non-priority PAHs. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 278:116838. [PMID: 33714059 DOI: 10.1016/j.envpol.2021.116838] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 02/06/2021] [Accepted: 02/21/2021] [Indexed: 06/12/2023]
Abstract
Knowledge of the toxic potential of polycyclic aromatic hydrocarbons (PAHs) has increased over time. Much of this knowledge is about the 16 United States - Environmental Protection Agency (US - EPA) priority PAHs; however, there are other US - EPA non-priority PAHs in the environment, whose toxic potential is underestimated. We conducted a systematic review of in vitro, in vivo, and in silico studies to assess the genotoxicity, mutagenicity, and carcinogenicity of 13 US - EPA non-priority parental PAHs present in the environment. Electronic databases, such as Science Direct, PubMed, Scopus, Google Scholar, and Web of Science, were used to search for research with selected terms without time restrictions. After analysis, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol, 249 articles, published between 1946 and 2020, were selected and the quality assessment of these studies was performed. The results showed that 5-methylchrysene (5-MC), 7,12-dimethylbenz[a]anthracene (7,12-DMBA), cyclopenta[cd]pyrene (CPP), and dibenzo[al]pyrene (Db[al]P) were the most studied PAHs. Moreover, 5-MC, 7,12-DMBA, benz[j]aceanthrylene (B[j]A), CPP, anthanthrene (ANT), dibenzo[ae]pyrene (Db[ae]P), and Db[al]P have been reported to cause mutagenic effects and have been being associated with a risk of carcinogenicity. Retene (RET) and benzo[c]fluorene (B[c]F), the least studied compounds, showed evidence of a strong influence on the mutagenicity and carcinogenicity endpoints. Overall, this systematic review provided evidence of the genotoxic, mutagenic, and carcinogenic endpoints of US - EPA non-priority PAHs. However, further studies are needed to improve the future protocols of environmental analysis and risk assessment in severely exposed populations.
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Affiliation(s)
- Francisco Carlos da Silva Junior
- Department of Cell Biology and Genetics, Biosciences Center, Federal University of Rio Grande Do Norte, Natal, RN, Brazil; Graduate Program in Molecular Biology and Biochemistry, Biosciences Center, Federal University of Rio Grande Do Norte, Natal, RN, Brazil
| | | | - Denis Elvis Farias de Castro
- Department of Cell Biology and Genetics, Biosciences Center, Federal University of Rio Grande Do Norte, Natal, RN, Brazil; Graduate Program in Molecular Biology and Biochemistry, Biosciences Center, Federal University of Rio Grande Do Norte, Natal, RN, Brazil
| | - Sinara Carla da Silva Araújo
- Department of Cell Biology and Genetics, Biosciences Center, Federal University of Rio Grande Do Norte, Natal, RN, Brazil; Graduate Program in Molecular Biology and Biochemistry, Biosciences Center, Federal University of Rio Grande Do Norte, Natal, RN, Brazil
| | - Herbert Costa Nóbrega Sisenando
- Department of Cell Biology and Genetics, Biosciences Center, Federal University of Rio Grande Do Norte, Natal, RN, Brazil; Department of Clinical and Toxicological Analysis, Health Sciences Center, Federal University of Rio Grande Do Norte, Natal, RN, Brazil
| | - Silvia Regina Batistuzzo de Medeiros
- Department of Cell Biology and Genetics, Biosciences Center, Federal University of Rio Grande Do Norte, Natal, RN, Brazil; Graduate Program in Molecular Biology and Biochemistry, Biosciences Center, Federal University of Rio Grande Do Norte, Natal, RN, Brazil.
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28
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Dad A, Revollo JR, Pearce MG, McKinzie PB, Heflich RH, Dobrovolsky VN. Pig-a gene mutations in bone marrow granulocytes of procarbazine-treated F344 rats. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2021; 62:265-272. [PMID: 33666279 DOI: 10.1002/em.22430] [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: 12/17/2020] [Revised: 03/02/2021] [Accepted: 03/03/2021] [Indexed: 06/12/2023]
Abstract
It was previously demonstrated that procarbazine (PCZ) is positive in the rat erythrocyte Pig-a gene mutation assay. However, since mammalian erythrocytes lack genomic DNA, it was necessary to analyze nucleated bone-marrow erythroid precursor cells to confirm that PCZ induces mutations in the Pig-a gene (Revollo et al., Environ Mol Mutagen, 2020). In this study, the association between Pig-a mutation and loss of GPI anchors was further strengthened and the genesis of Pig-a mutation in PCZ-dosed rats was evaluated by analyzing bone-marrow granulocytes. Erythrocytes and granulocytes both originate from myeloid progenitor cells, but granulocytes contain DNA throughout their developmental stages. F344 rats were treated with three doses of 150 mg/kg PCZ; 2 weeks later, CD48-deficient mutant phenotype bone-marrow granulocytes (BMGs [CD11b+ ]) were isolated by flow-cytometric sorting. Sequencing data showed that the CD48-deficient mutant phenotype BMGs contained mutations in the Pig-a gene while wild-type BMGs did not. PCZ-induced mutations included missense, nonsense and splice site variants; the majority of mutations were A > T, A > C, and A > G, with the mutated A on the nontranscribed DNA strand. The PCZ-induced mutational analysis in BMGs supports the association between the phenotype measured in the Pig-a assay and mutation in the Pig-a gene. Also, PCZ mutation spectra were similar in bone-marrow erythroids and BMGs, but none of the mutations detected in BMGs were the same as the erythroid precursor cell mutations from the same rats. Thus, mutations induced in the Pig-a assay appear to be induced after commitment of myeloid progenitor cells to either the granulocyte or erythroid pathway.
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Affiliation(s)
- Azra Dad
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas, USA
| | - Javier R Revollo
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas, USA
| | - Mason G Pearce
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas, USA
| | - Page B McKinzie
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas, USA
| | - Robert H Heflich
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas, USA
| | - Vasily N Dobrovolsky
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas, USA
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Chikura S, Kimoto T, Itoh S, Sanada H, Muto S, Horibata K. Standard protocol for the PIGRET assay, a high-throughput reticulocyte Pig-a assay with an immunomagnetic separation, used in the interlaboratory trial organized by the Mammalian Mutagenicity Study Group of the Japanese Environmental Mutagen and Genome Society. Genes Environ 2021; 43:10. [PMID: 33743813 PMCID: PMC7981892 DOI: 10.1186/s41021-021-00181-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 02/23/2021] [Indexed: 12/11/2022] Open
Abstract
The PIGRET assay is one of the Pig-a assays targeting reticulocytes (RETs), an in vivo genotoxicity evaluation method using flow cytometry with endogenous reporter glycosylphosphatidylinositol anchor protein. The PIGRET assay with RETs selectively enriched with anti-CD71 antibodies has several desirable features: high-throughput assay system, low background frequency of mutant cells, and early detection of mutation. To verify the potential and usefulness of the PIGRET assay for short-term testing, an interlaboratory trial involving 16 laboratories organized by the Mammalian Mutagenicity Study Group of the Japanese Environmental Mutagen and Genome Society was conducted. The collaborating laboratories assessed the mutagenicities of a total of 24 chemicals in rats using a single-treatment design and standard protocols for conducting the Pig-a assay on the total red blood cell assay and the PIGRET assay. Here the standard protocol for the PIGRET assay was described in detail.
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Affiliation(s)
- Satsuki Chikura
- Toxicology Research Department, Teijin Institute for Bio-medical Research, Teijin Pharma Limited, 4-3-2 Asahigaoka, Hino-shi, Tokyo, 191-8512, Japan
| | - Takafumi Kimoto
- Toxicology Research Department, Teijin Institute for Bio-medical Research, Teijin Pharma Limited, 4-3-2 Asahigaoka, Hino-shi, Tokyo, 191-8512, Japan.
| | - Satoru Itoh
- Medicinal Safety Research Laboratories, Daiichi Sankyo Co., Ltd., 1-16-13, Kitakasai, Edogawa-ku, Tokyo, 134-8630, Japan
| | - Hisakazu Sanada
- Development ADMET Department, Translational Research Division, Chugai Pharmaceutical Co., Ltd., 1-135 Komakado, Gotemba-shi, 412-8513, Japan
| | - Shigeharu Muto
- Safety Research Laboratories, Mitsubishi Tanabe Pharma Corporation, Shonan Health Innovation Park, 2-26-1, Muraoka-Higashi, Fujisawa, Kanagawa, 251-8555, Japan
| | - Katsuyoshi Horibata
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa, 210-9501, Japan.
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Dertinger SD, Bhalli JA, Roberts DJ, Stankowski LF, Gollapudi BB, Lovell DP, Recio L, Kimoto T, Miura D, Heflich RH. Recommendations for conducting the rodent erythrocyte Pig-a assay: A report from the HESI GTTC Pig-a Workgroup. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2021; 62:227-237. [PMID: 33608913 PMCID: PMC7986863 DOI: 10.1002/em.22427] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 02/08/2021] [Accepted: 02/17/2021] [Indexed: 05/19/2023]
Abstract
The rodent Pig-a assay is a flow cytometric, phenotype-based method used to measure in vivo somatic cell mutation. An Organization for Economic Co-operation and Development (OECD) test guideline is currently being developed to support routine use of the assay for regulatory purposes (OECD project number 4.93). This article provides advice on best practices for designing and conducting rodent Pig-a studies in support of evaluating test substance safety, with a focus on the rat model. Various aspects of assay conduct, including laboratory proficiency, minimum number of animals per dose group, preferred treatment and blood sampling schedule, and statistical analysis are described.
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Affiliation(s)
| | | | | | | | | | | | - Leslie Recio
- Integrated Laboratory SystemsResearch Triangle ParkNorth CarolinaUSA
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Ware RE, Dertinger SD. Absence of hydroxyurea-induced mutational effects supports higher utilisation for the treatment of sickle cell anaemia. Br J Haematol 2021; 194:252-266. [PMID: 33570176 DOI: 10.1111/bjh.17323] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 12/21/2020] [Indexed: 12/21/2022]
Abstract
Hydroxyurea (hydroxycarbamide) is approved for treating both children and adults with sickle cell anaemia (SCA). Fetal haemoglobin (HbF) induction is the primary treatment response, along with improved anaemia, reduced haemolysis, myelosuppression and decreased endothelial inflammation. Hydroxyurea has proven clinical efficacy for SCA - treatment significantly reduces disease manifestations and prolongs survival. Despite these recognised benefits, long-standing concerns regarding the risks of mutagenic and potentially carcinogenic drug exposure have hampered efforts for broad hydroxyurea use in SCA, although these are based largely on outdated experimental models and treatment experiences with myeloproliferative neoplasms. Consequently, many patients with SCA are not receiving this highly effective disease-modifying therapy. In this review, we describe the concept of genotoxicity and its laboratory measurements, summarise hydroxyurea-associated data from both preclinical and clinical studies, and discuss carcinogenic potential. The genotoxicity results clearly demonstrate that hydroxyurea does not directly bind DNA and is not mutagenic. Rather, its genotoxic effects are limited to indirect clastogenicity occurring in select cell types, and only when high dose and time thresholds are exceeded. This absence of mutagenic activity is consistent with the observed lack of any compelling carcinogenic potential. Since hydroxyurea therapy for SCA carries minimal carcinogenic risks, the current drug labelling should be modified accordingly, and prescribing practices should be broadened to allow better access and increased utilisation of this highly effective drug.
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Affiliation(s)
- Russell E Ware
- Division of Hematology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,Global Health Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
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Bonetto RM, Castel P, Robert SP, Tassistro VM, Claeys-Bruno M, Sergent M, Delecourt CA, Cowen D, Carcopino X, Orsière TG. Evaluation of PIG-A-mutated granulocytes and ex-vivo binucleated micronucleated lymphocytes frequencies after breast cancer radiotherapy in humans. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2021; 62:18-28. [PMID: 33169419 DOI: 10.1002/em.22413] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 10/30/2020] [Accepted: 11/06/2020] [Indexed: 06/11/2023]
Abstract
Although the PIG-A gene mutation frequency (MF) is considered a good proxy to evaluate the somatic MF in animals, evidence remains scarce in humans. In this study, a granulocyte PIG-A-mutant assay was evaluated in patients undergoing radiation therapy (RT) for breast cancer. Breast cancer patients undergoing adjuvant RT were prospectively enrolled. RT involved the whole breast, with (WBNRT) or without (WBRT) nodal area irradiation. Blood samples were obtained from participants before (T0) RT, and T1, T2, and T3 samples were collected 3 weeks after the initiation of RT, at the end of RT, and at least 10 weeks after RT discontinuation, respectively. The MF was assessed using a flow cytometry protocol identifying PIG-A-mutant granulocytes. Cytokinesis-blocked micronucleated lymphocyte (CBML) frequencies were also evaluated. Thirty patients were included, and five of them had received chemotherapy prior to RT. The mean (±SD) PIG-A MFs were 7.7 (±12.1) per million at T0, 5.2 (±8.6) at T1, 6.4 (±8.0) at T2 and 3.8 (±36.0) at T3. No statistically significant increases were observed between the PIG-A MF at T0 and the MFs at other times. RT significantly increased the CBML frequencies: 7.9 ‰ (±3.1‰) versus 33.6‰ (±17.2‰) (p < .0001). By multivariate analysis, the CBML frequency was correlated with age at RT initiation (p = .043) and irradiation volume at RT discontinuation (p = .0001) but not with chemotherapy. RT for breast cancer therapy failed to induce an increase in the PIG-A MF. The PIG-A assay in humans needs further evaluation, in various genotoxic exposures and including various circulating human cells.
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Affiliation(s)
- Rémi M Bonetto
- Aix Marseille University, APHM, CHU TIMONE, Service de Radiothérapie-Oncologie, Marseille, France
| | - Pierre Castel
- Aix Marseille University, Avignon Université, CNRS, IRD, IMBE, Marseille, France
| | - Stéphane P Robert
- Aix Marseille University, INSERM, INRA, C2VN, AMUTICYT Core Facility, Faculté de Pharmacie, Marseille, France
| | - Virginie M Tassistro
- Aix Marseille University, Avignon Université, CNRS, IRD, IMBE, Marseille, France
| | - Magalie Claeys-Bruno
- Aix Marseille University, Avignon Université, CNRS, IRD, IMBE, Marseille, France
| | - Michelle Sergent
- Aix Marseille University, Avignon Université, CNRS, IRD, IMBE, Marseille, France
| | - Camille A Delecourt
- Aix Marseille University, Avignon Université, CNRS, IRD, IMBE, Marseille, France
| | - Didier Cowen
- Aix Marseille University, APHM, CHU TIMONE, Service de Radiothérapie-Oncologie, Marseille, France
| | - Xavier Carcopino
- Aix Marseille University, Avignon Université, CNRS, IRD, IMBE, Marseille, France
- Aix Marseille University, APHM, CHU NORD, Service de Gynécologie-Obstétrique, Marseille, France
| | - Thierry G Orsière
- Aix Marseille University, Avignon Université, CNRS, IRD, IMBE, Marseille, France
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Kirby C, Baig A, Avlasevich SL, Torous DK, Tian S, Singh P, Bemis JC, Saubermann LJ, Dertinger SD. Dextran sulfate sodium mouse model of inflammatory bowel disease evaluated for systemic genotoxicity via blood micronucleus and Pig-a gene mutation assays. Mutagenesis 2020; 35:161-167. [PMID: 32050029 DOI: 10.1093/mutage/geaa006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 01/24/2020] [Indexed: 12/31/2022] Open
Abstract
Inflammatory bowel disease (IBD) is an important risk factor for gastrointestinal cancers. Inflammation and other carcinogenesis-related effects at distal, tissue-specific sites require further study. In order to better understand if systemic genotoxicity is associated with IBD, we exposed mice to dextran sulfate sodium salt (DSS) and measured the incidence of micronucleated cells (MN) and Pig-a mutant phenotype cells in blood erythrocyte populations. In one study, 8-week-old male CD-1 mice were exposed to 0, 1, 2, 3 or 4% w/v DSS in drinking water. The 4-week in-life period was divided into four 1-week intervals-alternately on then off DSS treatment. Low volume blood samples were collected for MN analysis at the end of each week, and cardiac blood samples were collected at the end of the 4-week period for Pig-a analyses. The two highest doses of DSS were observed to induce significant increases in reticulocyte frequencies. Even so, no statistically significant treatment-related effects on the genotoxicity biomarkers were evident. While one high-dose mouse showed modestly elevated MN frequencies during the DSS treatment cycles, it also exhibited exceptionally high reticulocyte frequencies (e.g. 18.7% at the end of the second DSS cycle). In a second study, mice were treated with 0 or 4% DSS for 9-18 consecutive days. Exposure was continued until rectal bleeding or morbidity was evident, at which point the treatment was terminated and blood was collected for MN analysis. The Pig-a assay was conducted on samples collected 29 days after the start of treatment. The initial blood specimens showed highly elevated reticulocyte frequencies in DSS-exposed mice (mean ± SEM = 1.75 ± 0.10% vs. 13.04 ± 3.66% for 0 vs. 4% mice, respectively). Statistical analyses showed no treatment-related effect on MN or Pig-a mutant frequencies. Even so, the incidence of MN versus reticulocytes in the DSS-exposed mice were positively correlated (linear fit R2 = 0.657, P = 0.0044). Collectively, these results suggest that in the case of the DSS CD-1 mouse model, systemic effects include stress erythropoiesis but not remarkable genotoxicity. To the extent MN may have been slightly elevated in a minority of individual mice, these effects appear to be secondary, likely attributable to stimulated erythropoiesis.
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Affiliation(s)
| | - Ayesha Baig
- Department of Pediatrics, University of Rochester Medical Center, Rochester, NY
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Kim JY, Lee AR, Choi YJ, Back SM, Kim OH, Moon KS, Kim SK. In vitro and in vivo assessment of the genotoxic effects of ceric ammonium nitrate and 1,3-propane sultone. Toxicol Lett 2020; 332:202-212. [PMID: 32659469 DOI: 10.1016/j.toxlet.2020.07.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 06/23/2020] [Accepted: 07/07/2020] [Indexed: 10/23/2022]
Abstract
A variety of methods have been developed for accurate and systematic evaluation of chemical genotoxicity. Ceric ammonium nitrate (CAN) and 1,3-propane sultone (1,3-PS) have been extensively applied in industrial fields. Although 1,3-PS, but not CAN, has been reported as a potent carcinogen, systematic assessment of the genotoxic properties of these chemicals has not been conducted. The purpose of this study was to establish a decision tree for evaluating genotoxicity based on the good laboratory practices (GLP) system using 1,3-PS and CAN as test chemicals. In vitro studies were performed including the bacterial reverse mutation assay, chromosomal aberration assay, and micronucleus assay. We conducted in vivo studies using a combined micronucleus and alkaline comet (MN-CMT) assay and the Pig-a gene mutation assay, which is a promising method for detecting gene mutations in vivo. CAN showed negative responses in all in vitro genotoxicity assays and the in vivo combined MN-CMT assay. Meanwhile, 1,3-PS had positive results in all in vitro and in vivo genotoxicity assays. In this study, we confirmed the genotoxicity of 1,3-PS and CAN using both in vitro and in vivo assays. We propose a decision tree for evaluating chemical-induced genotoxicity.
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Affiliation(s)
- Ji-Young Kim
- Department of Toxicological Evaluation and Research, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea; College of Pharmacy, Chungnam National University, Daejeon 34134, Republic of Korea
| | - A-Ram Lee
- Department of Toxicological Evaluation and Research, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea
| | - Young Jae Choi
- College of Pharmacy, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Sen-Min Back
- Department of Toxicological Evaluation and Research, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea
| | - Ok-Hee Kim
- Department of Toxicological Evaluation and Research, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea
| | - Kyoung-Sik Moon
- Department of Toxicological Evaluation and Research, Korea Institute of Toxicology, Daejeon 34114, Republic of Korea
| | - Sang Kyum Kim
- College of Pharmacy, Chungnam National University, Daejeon 34134, Republic of Korea.
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Revollo JR, Dad A, Pearce MG, Mittelstaedt RA, Casildo A, Lapidus RG, Robison TW, Dobrovolsky VN. CD59-deficient bone marrow erythroid cells from rats treated with procarbazine and propyl-nitrosourea have mutations in the Pig-a gene. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:797-806. [PMID: 32729949 DOI: 10.1002/em.22402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 07/09/2020] [Accepted: 07/24/2020] [Indexed: 06/11/2023]
Abstract
Procarbazine (PCZ) and N-propyl-N-nitrosourea (PNU) are rodent mutagens and carcinogens. Both induce GPI-anchored marker-deficient mutant-phenotype red blood cells (RBCs) in the flow cytometry-based rat RBC Pig-a assay. In the present study, we traced the origin of the RBC mutant phenotype by analyzing Pig-a mutations in the precursors of RBCs, bone marrow erythroid cells (BMEs). Rats were exposed to a total of 450 mg/kg PCZ hydrochloride or 300 mg/kg PNU, and bone marrow was collected 2, 7, and 10 weeks later. Using a flow cell sorter, we isolated CD59-deficient mutant-phenotype BMEs from PCZ- and PNU-treated rats and examined their endogenous X-linked Pig-a gene by next generation sequencing. Pig-a mutations consistent with the properties of PCZ and PNU were found in sorted mutant-phenotype BMEs. PCZ induced mainly A > T transversions with the mutated A on the nontranscribed strand of the Pig-a gene, while PNU induced mainly T > A transversions with the mutated T on the nontranscribed strand. The treatment-induced mutations were distributed across the protein coding sequence of the Pig-a gene. The causal relationship between BMEs and RBCs and the agent-specific mutational spectra in CD59-deicient BMEs indicate that the rat RBC Pig-a assay, scoring CD59-deficient mutant-phenotype RBCs in peripheral blood, detects Pig-a gene mutation.
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Affiliation(s)
- Javier R Revollo
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas, USA
| | - Azra Dad
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas, USA
| | - Mason G Pearce
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas, USA
| | - Roberta A Mittelstaedt
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas, USA
| | - Andrea Casildo
- Greenbaum Cancer Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Rena G Lapidus
- Greenbaum Cancer Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Timothy W Robison
- Division of Pulmonary, Allergy and Critical Care Products, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Vasily N Dobrovolsky
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas, USA
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Molecular analysis of GPI-anchor biosynthesis pathway genes in rat strains used for the Pig-a gene mutation assay. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2020; 858-860:503256. [DOI: 10.1016/j.mrgentox.2020.503256] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 08/05/2020] [Accepted: 09/11/2020] [Indexed: 11/20/2022]
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Torous DK, Avlasevich SL, Khattab MG, Baig A, Saubermann LJ, Chen Y, Bemis JC, Lovell DP, Walker VE, MacGregor JT, Dertinger SD. Human blood PIG-A mutation and micronucleated reticulocyte flow cytometric assays: Method optimization and evaluation of intra- and inter-subject variation. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:807-819. [PMID: 32572998 PMCID: PMC8582004 DOI: 10.1002/em.22393] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/17/2020] [Accepted: 06/18/2020] [Indexed: 05/05/2023]
Abstract
We previously described flow cytometry-based methods for scoring the incidence of micronucleated reticulocytes (MN-RET) and PIG-A mutant phenotype reticulocytes (MUT RET) in rodent and human blood samples. The current report describes important methodological improvements for human blood analyses, including immunomagnetic enrichment of CD71-positive reticulocytes prior to MN-RET scoring, and procedures for storing frozen blood for later PIG-A analysis. Technical replicate variability in MN-RET and MUT RET frequencies based on blood specimens from 14 subjects, intra-subject variability based on serial blood draws from 6 subjects, and inter-subject variation based on up to 344 subjects age 0 to 73 years were quantified. Inter-subject variation explained most of the variability observed for both endpoints (≥77%), with much lower intra-subject and technical replicate variability. The relatively large degree of inter-subject variation is apparent from mean and standard deviation values for MN-RET (0.15 ± 0.10%) and MUT RET (4.7 ± 5.0 per million, after omission of two extreme outliers). The influences of age and sex on inter-subject variation were investigated, and neither factor affected MN-RET whereas both influenced MUT RET frequency. The lowest MUT RET values were observed for subjects <11 years old, and males had moderately higher frequencies than females. These results indicate that MN-RET and MUT RET are automation-compatible biomarkers of genotoxicity that bridge species of toxicological interest to include human populations. These data will be useful for appropriately designing future human studies that include these biomarkers of genotoxicity, and highlight the need for additional work aimed at identifying the sources of inter-individual variability reported herein.
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Affiliation(s)
| | | | - Mona G. Khattab
- Department of Pediatrics, Baylor College of Medicine, Texas Children’s Hospital, Houston, Texas
| | - Ayesha Baig
- Department of Pediatrics, University of Rochester Medical Center, Rochester, New York
| | | | - Yuhchyau Chen
- Department of Radiation Oncology, University of Rochester Medical Center, Rochester, New York
| | | | | | - Vernon E. Walker
- Department of Pathology and Laboratory Medicine, University of Vermont, Burlington, Vermont
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2-Methylfuran: Toxicity and genotoxicity in male Sprague-Dawley rats. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2020; 854-855:503209. [DOI: 10.1016/j.mrgentox.2020.503209] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/06/2020] [Accepted: 06/08/2020] [Indexed: 11/22/2022]
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van der Leede B, Weiner S, Van Doninck T, De Vlieger K, Schuermans A, Tekle F, Geys H, van Heerden M, De Jonghe S, Van Gompel J. Testing of acetaminophen in support of the international multilaboratory in vivo rat Pig-a assay validation trial. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:508-525. [PMID: 32187737 PMCID: PMC7317746 DOI: 10.1002/em.22368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 03/09/2020] [Accepted: 03/13/2020] [Indexed: 06/10/2023]
Abstract
Acetaminophen, a nonmutagenic compound as previously concluded from bacteria, in vitro mammalian cell, and in vivo transgenic rat assays, presented a good profile as a nonmutagenic reference compound for use in the international multilaboratory Pig-a assay validation. Acetaminophen was administered at 250, 500, 1,000, and 2,000 mg·kg-1 ·day-1 to male Sprague Dawley rats once daily in 3 studies (3 days, 2 weeks, and 1 month with a 1-month recovery group). The 3-Day and 1-Month Studies included assessments of the micronucleus endpoint in peripheral blood erythrocytes and the comet endpoint in liver cells and peripheral blood cells in addition to the Pig-a assay; appropriate positive controls were included for each assay. Within these studies, potential toxicity of acetaminophen was evaluated and confirmed by inclusion of liver damage biomarkers and histopathology. Blood was sampled pre-treatment and at multiple time points up to Day 57. Pig-a mutant frequencies were determined in total red blood cells (RBCs) and reticulocytes (RETs) as CD59-negative RBC and CD59-negative RET frequencies, respectively. No increases in DNA damage as indicated through Pig-a, micronucleus, or comet endpoints were seen in treated rats. All positive controls responded as appropriate. Data from this series of studies demonstrate that acetaminophen is not mutagenic in the rat Pig-a model. These data are consistent with multiple studies in other nonclinical models, which have shown that acetaminophen is not mutagenic. At 1,000 mg·kg-1 ·day-1 , Cmax values of acetaminophen on Day 28 were 153,600 ng/ml and 131,500 ng/ml after single and repeat dosing, respectively, which were multiples over that of clinical therapeutic exposures (2.6-6.1 fold for single doses of 4,000 mg and 1,000 mg, respectively, and 11.5 fold for multiple dose of 4,000 mg) (FDA 2002). Data generated were of high quality and valid for contribution to the international multilaboratory validation of the in vivo Rat Pig-a Mutation Assay.
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Affiliation(s)
| | - Sandy Weiner
- Janssen Research & DevelopmentSpring House, PennsylvaniaUSA
| | | | | | | | - Fetene Tekle
- Janssen Research & DevelopmentBeerse, AntwerpBelgium
| | - Helena Geys
- Janssen Research & DevelopmentBeerse, AntwerpBelgium
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Dertinger SD, Avlasevich SL, Torous DK, Bemis JC, Hove TT, O'Connell O, Martus H, Elhajouji A. Intra- and inter-laboratory reproducibility of the rat blood Pig-a gene mutation assay. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:500-507. [PMID: 32187725 DOI: 10.1002/em.22367] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/24/2020] [Accepted: 03/13/2020] [Indexed: 06/10/2023]
Abstract
The in vivo Pig-a assay is being used in safety studies to evaluate the potential of chemicals to induce somatic cell gene mutations. Ongoing work is aimed at developing an Organization for Economic Cooperation and Development (OECD) test guideline to support routine use for regulatory purposes (OECD project number 4.93). Among the requirements for OECD approval are demonstrations of assay reliability, including reproducibility within and among laboratories. Experiments reported herein address the reproducibility of the rat blood Pig-a assay using the reference mutagens chlorambucil and melphalan. These agents were evaluated for their ability to induce Pig-a mutant erythrocytes in three separate studies conducted across two laboratories. Each of the studies utilized a common treatment schedule: 28 consecutive days of exposure via oral gavage. Whereas one laboratory studied Crl:CD(SD) rats, the other laboratory used Wistar Han rats. One or two days after cessation of treatment blood samples were collected for mutant reticulocyte and mutant erythrocyte measurements that were accomplished with the same analytical technique whereby samples were depleted of wildtype erythrocytes via immunomagnetic separation followed by flow cytometric enumeration of mutant phenotype cells (MutaFlow®). Dunnett's test results showed similar qualitative outcomes within and between laboratories, that is, each chemical and each study demonstrated statistically significant, dose-related increases in mutant reticulocyte and erythrocyte frequencies. Benchmark dose analysis (PROAST software) provided a means to quantitatively analyze the results, and the relatively tight, overlapping benchmark dose confidence intervals observed for each of the two chemicals indicate that within and between laboratory reproducibility of the Pig-a assay are high, adding further support for the development of an OECD test guideline.
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Affiliation(s)
| | | | | | | | - Tamsanqa Tafara Hove
- Preclinical Safety, Novartis Institutes for Biomedical Research, Novartis Pharma AG, Basel, Switzerland
| | - Oliver O'Connell
- Preclinical Safety, Novartis Institutes for Biomedical Research, Novartis Pharma AG, Basel, Switzerland
| | - Hansjoerg Martus
- Preclinical Safety, Novartis Institutes for Biomedical Research, Novartis Pharma AG, Basel, Switzerland
| | - Azeddine Elhajouji
- Preclinical Safety, Novartis Institutes for Biomedical Research, Novartis Pharma AG, Basel, Switzerland
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Hartwig A, Arand M, Epe B, Guth S, Jahnke G, Lampen A, Martus HJ, Monien B, Rietjens IMCM, Schmitz-Spanke S, Schriever-Schwemmer G, Steinberg P, Eisenbrand G. Mode of action-based risk assessment of genotoxic carcinogens. Arch Toxicol 2020; 94:1787-1877. [PMID: 32542409 PMCID: PMC7303094 DOI: 10.1007/s00204-020-02733-2] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 03/31/2020] [Indexed: 12/16/2022]
Abstract
The risk assessment of chemical carcinogens is one major task in toxicology. Even though exposure has been mitigated effectively during the last decades, low levels of carcinogenic substances in food and at the workplace are still present and often not completely avoidable. The distinction between genotoxic and non-genotoxic carcinogens has traditionally been regarded as particularly relevant for risk assessment, with the assumption of the existence of no-effect concentrations (threshold levels) in case of the latter group. In contrast, genotoxic carcinogens, their metabolic precursors and DNA reactive metabolites are considered to represent risk factors at all concentrations since even one or a few DNA lesions may in principle result in mutations and, thus, increase tumour risk. Within the current document, an updated risk evaluation for genotoxic carcinogens is proposed, based on mechanistic knowledge regarding the substance (group) under investigation, and taking into account recent improvements in analytical techniques used to quantify DNA lesions and mutations as well as "omics" approaches. Furthermore, wherever possible and appropriate, special attention is given to the integration of background levels of the same or comparable DNA lesions. Within part A, fundamental considerations highlight the terms hazard and risk with respect to DNA reactivity of genotoxic agents, as compared to non-genotoxic agents. Also, current methodologies used in genetic toxicology as well as in dosimetry of exposure are described. Special focus is given on the elucidation of modes of action (MOA) and on the relation between DNA damage and cancer risk. Part B addresses specific examples of genotoxic carcinogens, including those humans are exposed to exogenously and endogenously, such as formaldehyde, acetaldehyde and the corresponding alcohols as well as some alkylating agents, ethylene oxide, and acrylamide, but also examples resulting from exogenous sources like aflatoxin B1, allylalkoxybenzenes, 2-amino-3,8-dimethylimidazo[4,5-f] quinoxaline (MeIQx), benzo[a]pyrene and pyrrolizidine alkaloids. Additionally, special attention is given to some carcinogenic metal compounds, which are considered indirect genotoxins, by accelerating mutagenicity via interactions with the cellular response to DNA damage even at low exposure conditions. Part C finally encompasses conclusions and perspectives, suggesting a refined strategy for the assessment of the carcinogenic risk associated with an exposure to genotoxic compounds and addressing research needs.
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Affiliation(s)
- Andrea Hartwig
- Department of Food Chemistry and Toxicology, Institute of Applied Biosciences (IAB), Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany.
| | - Michael Arand
- Institute of Pharmacology and Toxicology, University of Zurich, 8057, Zurich, Switzerland
| | - Bernd Epe
- Institute of Pharmacy and Biochemistry, University of Mainz, 55099, Mainz, Germany
| | - Sabine Guth
- Department of Toxicology, IfADo-Leibniz Research Centre for Working Environment and Human Factors, TU Dortmund, Ardeystr. 67, 44139, Dortmund, Germany
| | - Gunnar Jahnke
- Department of Food Chemistry and Toxicology, Institute of Applied Biosciences (IAB), Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany
| | - Alfonso Lampen
- Department of Food Safety, German Federal Institute for Risk Assessment (BfR), 10589, Berlin, Germany
| | - Hans-Jörg Martus
- Novartis Institutes for BioMedical Research, 4002, Basel, Switzerland
| | - Bernhard Monien
- Department of Food Safety, German Federal Institute for Risk Assessment (BfR), 10589, Berlin, Germany
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Simone Schmitz-Spanke
- Institute and Outpatient Clinic of Occupational, Social and Environmental Medicine, University of Erlangen-Nuremberg, Henkestr. 9-11, 91054, Erlangen, Germany
| | - Gerlinde Schriever-Schwemmer
- Department of Food Chemistry and Toxicology, Institute of Applied Biosciences (IAB), Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany
| | - Pablo Steinberg
- Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Haid-und-Neu-Str. 9, 76131, Karlsruhe, Germany
| | - Gerhard Eisenbrand
- Retired Senior Professor for Food Chemistry and Toxicology, Kühler Grund 48/1, 69126, Heidelberg, Germany.
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Cao Y, Wang X, Liu W, Feng N, Xi J, You X, Chen R, Zhang X, Liu Z, Luan Y. The potential application of human PIG-A assay on azathioprine-treated inflammatory bowel disease patients. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:456-464. [PMID: 31743483 DOI: 10.1002/em.22348] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 10/25/2019] [Accepted: 11/15/2019] [Indexed: 06/10/2023]
Abstract
The rodent Pig-a assay has been used extensively as a potential regulatory assay for evaluating the in vivo mutagenicity of test substances. Although the assay can be conducted in different mammalian species, there have been only a few reports describing its use in humans, and rarely in genotoxicant-exposed human populations. In this study, PIG-A mutation frequencies (MFs) were evaluated in 36 azathioprine (AZA; human carcinogen)-treated inflammatory bowel disease (IBD) patients and 36 healthy volunteers. IBD patients exhibited a slight but statistically higher MF (6.10 ± 4.44 × 10-6 ) than healthy volunteers (4.97 ± 2.74 × 10-6 ) (P = 0.0489). The estimated relative risk for the exposed patients was 1.22 which indicated that AZA is a risk factor for inducing PIG-A mutation. However, the PIG-A MF showed no associations with AZA treatment duration or total AZA exposure. In addition, we performed the cytokinesis-block micronucleus test on the same samples. The frequencies of micronuclei (MN) and nuclear buds (NBUD) in IBD patients (MN: 4.70 ± 2.86‰; NBUD: 1.89 ± 0.95‰) were significantly higher than in healthy volunteers (MN: 1.47 ± 0.77‰, P < 0.001; NBUD: 0.90 ± 0.58‰, P = 0.004). MN frequency also had significant correlations with AZA treatment duration (P = 0.011) and total AZA exposure (P = 0.018). Our findings indicate that AZA-treated IBD patients have only a marginally significant increase in PIG-A MF; in contrast, a much stronger AZA-associated increase in genotoxicity was detected with the lymphocyte MN assay. Environ. Mol. Mutagen. 2019. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Yiyi Cao
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Xiaolei Wang
- Shanghai 10th People's Hospital, Shanghai, People's Republic of China
| | - Weiying Liu
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Nannan Feng
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Jing Xi
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Xinyue You
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Ruixue Chen
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - XinYu Zhang
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Zhanju Liu
- Shanghai 10th People's Hospital, Shanghai, People's Republic of China
| | - Yang Luan
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
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Li XL, Guo XQ, Wang HR, Chen T, Mei N. Aristolochic Acid-Induced Genotoxicity and Toxicogenomic Changes in Rodents. WORLD JOURNAL OF TRADITIONAL CHINESE MEDICINE 2020; 6:12-25. [PMID: 32258091 PMCID: PMC7110418 DOI: 10.4103/wjtcm.wjtcm_33_19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Aristolochic acid (AA) is a group of structurally related nitrophenanthrene carboxylic acids found in many plants that are widely used by many cultures as traditional herbal medicines. AA is a causative agent for Chinese herbs nephropathy, a term replaced later by AA nephropathy. Evidence indicates that AA is nephrotoxic, genotoxic, and carcinogenic in humans; and it also induces tumors in the forestomach, kidney, renal pelvis, urinary bladder, and lung of rats and mice. Therefore, plants containing AA have been classified as carcinogenic to humans (Group 1) by the International Agency for Research on Cancer. In our laboratories, we have conducted a series of genotoxicity and toxicogenomic studies in the rats exposed to AA of 0.1–10 mg/kg for 12 weeks. Our results demonstrated that AA treatments induced DNA adducts and mutations in the kidney, liver, and spleen of rats, as well as significant alteration of gene expression in both its target and nontarget tissues. AA treatments altered mutagenesis- or carcinogenesis-related microRNA expression in rat kidney and resulted in significant changes in protein expression profiling. We also applied benchmark dose (BMD) modeling to the 3-month AA-induced genotoxicity data. The obtained BMDL10 (the lower 95% confidence interval of the BMD10 that is a 10% increase over the background level) for AA-induced mutations in the kidney of rats was about 7 μg/kg body weight per day. This review constitutes an overview of our investigations on AA-induced genotoxicity and toxicogenomic changes including gene expression, microRNA expression, and proteomics; and presents updated information focused on AA-induced genotoxicity in rodents.
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Affiliation(s)
- Xi-Lin Li
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, Jefferson, AR, USA
| | - Xiao-Qing Guo
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, Jefferson, AR, USA
| | - Hai-Rong Wang
- Tianjin Center for New Drug Safety Assessment and Research, Tianjin, China
| | - Tao Chen
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, Jefferson, AR, USA
| | - Nan Mei
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, Jefferson, AR, USA
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Chen R, Zhou C, Cao Y, Xi J, Ohira T, He L, Huang P, You X, Liu W, Zhang X, Ma S, Xie T, Chang Y, Luan Y. Assessment of Pig-a, Micronucleus, and Comet Assay Endpoints in Tg.RasH2 Mice Carcinogenicity Study of Aristolochic Acid I. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:266-275. [PMID: 31443125 DOI: 10.1002/em.22325] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 08/16/2019] [Accepted: 08/19/2019] [Indexed: 06/10/2023]
Abstract
A newly developed in vivo Pig-a gene mutation assay displays great potential for integration into genotoxicity tests. To obtain more evidence for application of the Pig-a assay, we integrated this assay, micronucleus test in peripheral blood (MN-pb test) and bone marrow (MN-bm test), as well as a Comet assay into a transgenic RasH2 mice carcinogenicity study. Fourteen male RasH2 mice and five wild-type (WT) mice were treated with a strong mutagen aristolochic acid I at a dose of 5 mg/kg/day for 4 consecutive weeks. Mice recovered in 5 weeks. Peripheral bloods were collected for Pig-a assay, MN-pb test, and Comet assay at several time points, while bone marrow and target organs were harvested for the MN-bm test and pathological diagnosis after mice were euthanized. Finally, 13 of the 14 RasH2 mice developed squamous cell carcinomas in the forestomach, while there were no carcinomas in the WT mice. Pig-a mutant frequencies (MFs) consecutively increased throughout the study to a maximum value of approximately 63-fold more than background. These frequencies were relative to the incidence, size, and malignant degree of tumors. Micronucleated reticulocytes increased from Day 1 to Day 49, before returning to background levels. No positive responses were observed in either the MN-bm test or the Comet assay. Results suggested that, when compared with the other two tests, the Pig-a assay persistently contributed to sustaining MFs, enhanced detection sensitivity due to the accumulation of Pig-a mutations, and demonstrated better predictability for tumorigenicity. Environ. Mol. Mutagen. 61:266-275, 2020. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Ruixue Chen
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Changhui Zhou
- Shanghai InnoStar Bio-Tech Co., Ltd., National Shanghai Center for New Drug Safety Evaluation and Research, Shanghai, People's Republic of China
| | - Yiyi Cao
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
- Joint Laboratory on Herbal Safety, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Jing Xi
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
- Joint Laboratory on Herbal Safety, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Toko Ohira
- Shanghai InnoStar Bio-Tech Co., Ltd., National Shanghai Center for New Drug Safety Evaluation and Research, Shanghai, People's Republic of China
| | - Liang He
- Shanghai InnoStar Bio-Tech Co., Ltd., National Shanghai Center for New Drug Safety Evaluation and Research, Shanghai, People's Republic of China
| | - Pengcheng Huang
- Shanghai InnoStar Bio-Tech Co., Ltd., National Shanghai Center for New Drug Safety Evaluation and Research, Shanghai, People's Republic of China
| | - Xinyue You
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Weiying Liu
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Xinyu Zhang
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
- Joint Laboratory on Herbal Safety, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Shuangcheng Ma
- Joint Laboratory on Herbal Safety, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
- National Institutes for Food and Drug Control, Beijing, China
| | - Tianpei Xie
- Joint Laboratory on Herbal Safety, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
- Shanghai Standard Technology Co., Ltd., Shanghai, People's Republic of China
| | - Yan Chang
- Shanghai InnoStar Bio-Tech Co., Ltd., National Shanghai Center for New Drug Safety Evaluation and Research, Shanghai, People's Republic of China
| | - Yang Luan
- School of Public Health, Hongqiao International Institute of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
- Joint Laboratory on Herbal Safety, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
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Martus HJ, Froetschl R, Gollapudi B, Honma M, Marchetti F, Pfuhler S, Schoeny R, Uno Y, Yauk C, Kirkland DJ. Summary of major conclusions from the 7th International Workshop on Genotoxicity Testing (IWGT), Tokyo, Japan. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2020; 852:503134. [PMID: 32265038 DOI: 10.1016/j.mrgentox.2020.503134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Hans-Joerg Martus
- Novartis Institutes for BioMedical Research, Preclinical Safety, 4002 Basel, Switzerland.
| | - Roland Froetschl
- BfArM Federal Institute for Drugs and Medical Devices, Bonn, Germany
| | - Bhaskar Gollapudi
- Exponent, Inc., Center for Health Sciences, 1800 Diagonal Road, Alexandria, VA, 22314, USA
| | - Masamitsu Honma
- National Institute of Health Sciences, Division of Genetics & Mutagenesis, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo, 158-8501, Japan
| | - Francesco Marchetti
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Stefan Pfuhler
- Global Product Stewardship- Human Safety, Procter & Gamble, Mason, OH, USA
| | - Rita Schoeny
- Rita Schoeny LLC, Washington DC, 20002, United States
| | | | - Carole Yauk
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada
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White PA, Long AS, Johnson GE. Quantitative Interpretation of Genetic Toxicity Dose-Response Data for Risk Assessment and Regulatory Decision-Making: Current Status and Emerging Priorities. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:66-83. [PMID: 31794061 DOI: 10.1002/em.22351] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 11/27/2019] [Accepted: 11/30/2019] [Indexed: 06/10/2023]
Abstract
The screen-and-bin approach for interpretation of genotoxicity data is predicated on three false assumptions: that genotoxicants are rare, that genotoxicity dose-response functions do not contain a low-dose region mechanistically characterized by zero-order kinetics, and that genotoxicity is not a bona fide toxicological endpoint. Consequently, there is a need to develop and implement quantitative methods to interpret genotoxicity dose-response data for risk assessment and regulatory decision-making. Standardized methods to analyze dose-response data, and determine point-of-departure (PoD) metrics, have been established; the most robust PoD is the benchmark dose (BMD). However, there are no standards for regulatory interpretation of mutagenicity BMDs. Although 5-10% is often used as a critical effect size (CES) for BMD determination, values for genotoxicity endpoints have not been established. The use of BMDs to determine health-based guidance values (HBGVs) requires assessment factors (AFs) to account for interspecies differences and variability in human sensitivity. Default AFs used for other endpoints may not be appropriate for interpretation of in vivo mutagenicity BMDs. Analyses of published dose-response data showing the effects of compensatory pathway deficiency indicate that AFs for sensitivity differences should be in the range of 2-20. Additional analyses indicate that the AF to compensate for short treatment durations should be in the range of 5-15. Future work should use available data to empirically determine endpoint-specific CES values; similarly, to determine AF values for BMD adjustment. Future work should also evaluate the ability to use in vitro dose-response data for risk assessment, and the utility of probabilistic methods for determination of mutagenicity HBGVs. Environ. Mol. Mutagen. 61:66-83, 2020. © 2019 Her Majesty the Queen in Right of Canada.
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Affiliation(s)
- Paul A White
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Alexandra S Long
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
| | - George E Johnson
- Swansea University Medical School, Swansea, Wales, United Kingdom
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Sasaki JC, Allemang A, Bryce SM, Custer L, Dearfield KL, Dietz Y, Elhajouji A, Escobar PA, Fornace AJ, Froetschl R, Galloway S, Hemmann U, Hendriks G, Li HH, Luijten M, Ouedraogo G, Peel L, Pfuhler S, Roberts DJ, Thybaud V, van Benthem J, Yauk CL, Schuler M. Application of the adverse outcome pathway framework to genotoxic modes of action. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:114-134. [PMID: 31603995 DOI: 10.1002/em.22339] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/17/2019] [Accepted: 09/23/2019] [Indexed: 05/22/2023]
Abstract
In May 2017, the Health and Environmental Sciences Institute's Genetic Toxicology Technical Committee hosted a workshop to discuss whether mode of action (MOA) investigation is enhanced through the application of the adverse outcome pathway (AOP) framework. As AOPs are a relatively new approach in genetic toxicology, this report describes how AOPs could be harnessed to advance MOA analysis of genotoxicity pathways using five example case studies. Each of these genetic toxicology AOPs proposed for further development includes the relevant molecular initiating events, key events, and adverse outcomes (AOs), identification and/or further development of the appropriate assays to link an agent to these events, and discussion regarding the biological plausibility of the proposed AOP. A key difference between these proposed genetic toxicology AOPs versus traditional AOPs is that the AO is a genetic toxicology endpoint of potential significance in risk characterization, in contrast to an adverse state of an organism or a population. The first two detailed case studies describe provisional AOPs for aurora kinase inhibition and tubulin binding, leading to the common AO of aneuploidy. The remaining three case studies highlight provisional AOPs that lead to chromosome breakage or mutation via indirect DNA interaction (inhibition of topoisomerase II, production of cellular reactive oxygen species, and inhibition of DNA synthesis). These case studies serve as starting points for genotoxicity AOPs that could ultimately be published and utilized by the broader toxicology community and illustrate the practical considerations and evidence required to formalize such AOPs so that they may be applied to genetic toxicity evaluation schemes. Environ. Mol. Mutagen. 61:114-134, 2020. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
| | | | | | - Laura Custer
- Bristol-Myers Squibb Company, Drug Safety Evaluation, New Brunswick, New Jersey
| | | | - Yasmin Dietz
- Sanofi-Aventis Deutschland GmbH, Frankfurt, Germany
| | | | | | | | | | | | | | | | - Heng-Hong Li
- Georgetown University, Washington, District of Columbia
| | - Mirjam Luijten
- National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | | | - Lauren Peel
- Health and Environmental Sciences Institute, Washington, District of Columbia
| | | | | | - Véronique Thybaud
- Sanofi, Research and Development, Preclinical Safety, Vitry-sur-Seine, France
| | - Jan van Benthem
- National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - Carole L Yauk
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Maik Schuler
- Pfizer Inc, World Wide Research and Development, Groton, Connecticut
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Tian X, Chen Y, Nakamura J. Development of a novel PIG-A gene mutation assay based on a GPI-anchored fluorescent protein sensor. Genes Environ 2019; 41:21. [PMID: 31867084 PMCID: PMC6902599 DOI: 10.1186/s41021-019-0135-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 11/14/2019] [Indexed: 11/19/2022] Open
Abstract
Background Accumulation of somatic mutations caused by both endogenous and exogenous exposures is a high risk for human health, in particular, cancer. Efficient detection of somatic mutations is crucial for risk assessment of different types of exposures. Due to its requirement in the process of attaching glycosylphatidylinositol- (GPI-) anchored proteins to the cell surface, the PIG-A gene located on the X-chromosome is used in both in vivo and in vitro mutation assays. Loss-of-function mutations in PIG-A lead to the elimination of GPI-anchored proteins such that they can no longer be detected on the cell surface by antibodies. Historically, mutation assays based on the PIG-A gene rely on the staining of these cell-surface proteins by antibodies; however, as with any antibody-based assay, there are major limitations, especially in terms of variability and lack of specific antibodies. Results In the current study, we developed a modified PIG-A mutation assay that uses the expression of GPI-anchored fluorescent proteins (henceforth referred to as a GPI-sensor), whereby the presence of fluorescence on the cell membrane is dependent on the expression of wild-type PIG-A. Using our modified PIG-A mutation assay, we have achieved complete separation of wild type cells and spontaneously mutated cells, in which the presence of PIG-A mutations has been confirmed via proaerolysin resistance and gene sequencing. Conclusion This study establishes a novel PIG-A mutation assay using GPI-anchored fluorescent protein expression that eliminates the need for antibody-based staining. This GPI-sensor PIG-A mutation assay should be widely applicable for accurate and efficient testing of genotoxicity for use in many mammalian and vertebrate cells.
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Affiliation(s)
- Xu Tian
- 1Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC USA
| | - Youjun Chen
- 2Department of Neurology, UNC Neuroscience center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina USA
| | - Jun Nakamura
- 1Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC USA.,3Laboratory of Laboratory Animal Science, Graduate School of Life and Environmental Biosciences, Osaka Prefecture University, Izumisano, Osaka, Japan
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Masuda-Herrera MJ, Dobo KL, Kenyon MO, Kenny JD, Galloway SM, Escobar PA, Reddy MV, Jolly RA, Trejo-Martin A, Brown C, Mckeon M, Young M, Bruce S, Pant K, Dutta A, Kulkarni R, Bercu JP. In Vivo Mutagenicity Testing of Arylboronic Acids and Esters. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2019; 60:766-777. [PMID: 31335992 DOI: 10.1002/em.22320] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 07/09/2019] [Accepted: 07/15/2019] [Indexed: 06/10/2023]
Abstract
Arylboronic acids and esters (referred to collectively as arylboronic compounds) are commonly used intermediates in the synthesis of pharmaceuticals but pose a challenge for chemical syntheses because they are often positive for bacterial mutagenicity in vitro. As such, arylboronic compounds are then typically controlled to levels that are acceptable for mutagenic impurities, that is, the threshold of toxicological concern (TTC). This study used ICH M7 guidance to design and conduct a testing strategy to investigate the in vivo relevance of the in vitro positive findings of arylboronic compounds. Eight arylboronic compounds representing a variety of chemical scaffolds were tested in Sprague Dawley and/or Wistar rats in the in vivo Pig-a (peripheral blood reticulocytes and mature red blood cells) and/or comet assays (duodenum and/or liver). Five of the eight compounds were also tested in the micronucleus (peripheral blood) assay. The arylboronic compounds tested orally demonstrated high systemic exposure; thus the blood and bone marrow were adequately exposed to test article. One compound was administered intravenously due to formulation stability issues. This investigation showed that arylboronic compounds that were mutagenic in vitro were not found to be mutagenic in the corresponding in vivo assays. Therefore, arylboronic compounds similar to the scaffolds tested in this article may be considered non-mutagenic and managed in accordance with the ICH Q3A/Q3B guidelines. Environ. Mol. Mutagen. 2019. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
| | - Krista L Dobo
- Pfizer Global Research & Development, Groton, Connecticut, 06340
| | | | - Julia D Kenny
- GlaxoSmithKline, Hertfordshire, SG12 0DP, United Kingdom
| | | | | | | | - Robert A Jolly
- Toxicology Division, Eli Lilly and Company, Indianapolis, Indiana
| | | | - Caren Brown
- MilliporeSigma BioReliance® Toxicology Services, Rockville, Maryland
| | - Marie Mckeon
- MilliporeSigma BioReliance® Toxicology Services, Rockville, Maryland
| | - Megan Young
- MilliporeSigma BioReliance® Toxicology Services, Rockville, Maryland
| | - Shannon Bruce
- MilliporeSigma BioReliance® Toxicology Services, Rockville, Maryland
| | - Kamala Pant
- MilliporeSigma BioReliance® Toxicology Services, Rockville, Maryland
| | - Aparajita Dutta
- MilliporeSigma BioReliance® Toxicology Services, Rockville, Maryland
| | - Rohan Kulkarni
- MilliporeSigma BioReliance® Toxicology Services, Rockville, Maryland
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Bhalli JA, Neft R, Noteboom J, Tebbe CC, Chan M, Kuhn K, Pearce G, Jordan L, Beevers C. Caffeic Acid Genotoxicity: Correlation of the Pig-a Assay with Regulatory Genetic Toxicology In Vivo Endpoints. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2019; 60:837-844. [PMID: 31490579 DOI: 10.1002/em.22333] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 08/26/2019] [Accepted: 08/30/2019] [Indexed: 05/14/2023]
Abstract
Caffeic acid is found in variety of fruits and vegetables. It is considered as possible human carcinogen (Group 2B). It is negative in Ames and mouse micronucleus (MN), but positive in mouse lymphoma and chromosomal aberration assays. The objective of this study was to evaluate the in vivo genotoxicity of caffeic acid using three different endpoints: in vivo MN, Pig-a, and comet assay. Two sets of six rats per group were administered vehicle (0.5% hydroxypropyl methylcellulose), 500, 1,000, or 2,000 mg/kg/day of caffeic acid for three consecutive days via oral gavage. One set of animals was used for the Pig-a and MN assay and the other set was used for the comet assay. N-Ethyl N-Nitrosourea was used as positive control for the Pig-a and MN assay, and ethyl methanesulfonate for the comet assay. From one set of animals, peripheral blood was collected on Days -1, 14, and 30 for the Pig-a assay and on Day 4 for the MN assay. The other set of animals was euthanized 3 hr after the last dose; liver and blood were collected for the comet assay. A statistically significant increase in the MN frequency was observed at 2,000 mg/kg/day. No increase in the red blood cells (RBCCD59- ) or reticulocytes (RETCD59- ) Pig-a mutant frequencies was observed on Days 14 or 30. No increase in DNA strand breaks was observed in the peripheral blood or liver in the comet assay. Environ. Mol. Mutagen. 2019. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
| | - Robin Neft
- Covance Laboratories Inc., Greenfield, Indiana
| | | | | | | | - Kylie Kuhn
- Covance Laboratories Inc., Greenfield, Indiana
| | - Gareth Pearce
- Covance Laboratories Limited, Harrogate, HG3 1PY, United Kingdom
| | - Liam Jordan
- Covance Laboratories Limited, Harrogate, HG3 1PY, United Kingdom
| | - Carol Beevers
- Covance Laboratories Limited, Harrogate, HG3 1PY, United Kingdom
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