A new tool for genotoxic risk assessment: Reevaluation of the cytokinesis-block micronucleus assay using semi-automated scoring following telomere and centromere staining
| Autor: | Mustafa Al Jawhari, Olivier Cariou, Bruno Colicchio, Patrice Carde, Leonhard Heidingsfelder, William M. Hempel, Besma Bel Hadj Jrad, Alain Dieterlen, Philippe Voisin, Eric Laplagne, Radhia M'kacher, Narjes Zaguia, Eric Jeandidier |
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| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
DNA damage Health Toxicology and Mutagenesis Centromere medicine.disease_cause Risk Assessment 03 medical and health sciences chemistry.chemical_compound Clastogen 0302 clinical medicine Genetics medicine Humans Lymphocytes Cytochalasin B Micronuclei Chromosome-Defective Cytokinesis Micronucleus Tests Chemistry Mutagenicity Tests Telomere Aneugens Molecular biology Staining 030104 developmental biology 030220 oncology & carcinogenesis Micronucleus test Aneugen Micronucleus Genotoxicity DNA Damage Mutagens |
| Zdroj: | Mutation research. Genetic toxicology and environmental mutagenesis. |
| ISSN: | 1879-3592 |
| Popis: | Background The cytokinesis-block micronucleus (CBMN) assay is an internationally recognized method for measuring DNA damage after exposure to genotoxic agents, as well as a biomarker for DNA repair and chromosomal instability. The high baseline level of micronuclei (MN) in the healthy population has limited the sensitivity and application of the CBMN assay for the follow-up of exposed populations. We reevaluated the sensitivity of the CBNM assay using semi-automated MN scoring following telomere and centromere (TC) staining after in vitro exposure to genotoxic agents (mitomycin or radiation) or aneugenic agents (vinblastine). Materials and methods Blood samples from 12 healthy donors were exposed to 137Cs at seven doses from 0.1–4 Gy and cultured for 72 h. Cytochalasin B was added at 46 h of culture. The exposure of chemical agents (mitomycin or vinblastine) was performed after 48 h of culture for 3 h. Cytochalasin B was added after treatment and slides were prepared 24 h after. MN was semi-automatically scored following TC staining. Nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) were assessed in a human cell line after TC staining. Results The introduction TC staining to the scoring of MN not only renders MN scoring more efficient and robust, but also permits discrimination between exposure to clastogenic (MN with only telomere signals) and aneugenic agents (MN with both TC signals). The resulting improvement of MN detection led to an increase in the sensitivity of the CBMN assay following low-dose radiation exposure (0.3 versus 0.1 Gy). Hyperradiosensitivity phenomenon was observed after low dose exposure. A dose-response curve was obtained for up to 4 Gy. In addition, TC staining permits assessment of the nature of NPBs and NBUDs as biomarkers for genotoxicity and chromosomal instability. Conclusion These approaches can be potentially used to follow-up populations exposed to genotoxic agents and assess cancer risk. |
| Databáze: | OpenAIRE |
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