Genotoxic Effects of Etoposide, Bleomycin, and Ethyl Methanesulfonate on Cultured CHO Cells: Analysis by GC-MS/MS and Comet Assay

Donald H Atha; Erdem Coskun; Onur Erdem; Alessandro Tona; Vytas Reipa; Bryant C Nelson

doi:10.1155/2020/8810105

Genotoxic Effects of Etoposide, Bleomycin, and Ethyl Methanesulfonate on Cultured CHO Cells: Analysis by GC-MS/MS and Comet Assay

J Nucleic Acids. 2020 Jul 30:2020:8810105. doi: 10.1155/2020/8810105. eCollection 2020.

Authors

Donald H Atha¹, Erdem Coskun^{2

3}, Onur Erdem^{2

4}, Alessandro Tona¹, Vytas Reipa¹, Bryant C Nelson¹

Affiliations

¹ National Institute of Standards and Technology, Biosystems and Biomaterials Division, Materials Measurement Laboratory, Gaithersburg, MD 20899, USA.
² National Institute of Standards and Technology, Biomolecular Measurement Division, Materials Measurement Laboratory, Gaithersburg, MD 20899, USA.
³ University of Maryland, Institute for Bioscience and Biotechnology Research, Rockville, MD 20850, USA.
⁴ University of Health Sciences Turkey, Department of Pharmaceutical Toxicology, Gulhane Faculty of Pharmacy, 06010 Ankara, Turkey.

Abstract

To evaluate methods for analysis of genotoxic effects on mammalian cell lines, we tested the effect of three common genotoxic agents on Chinese hamster ovary (CHO) cells by single-cell gel electrophoresis (comet assay) and gas chromatography-tandem mass spectrometry (GC-MS/MS). Suspension-grown CHO cells were separately incubated with etoposide, bleomycin, and ethyl methanesulfonate and analyzed by an alkaline comet assay and GC-MS/MS. Although DNA strand breaks were detected by the comet assay after treatment with all three agents, GC-MS/MS could only detect DNA nucleobase lesions oxidatively induced by bleomycin. This demonstrates that although GC-MS/MS has limitations in detection of genotoxic effects, it can be used for selected chemical genotoxins that contribute to oxidizing processes. The comet assay, used in combination with GC-MS/MS, can be a more useful approach to screen a wide range of chemical genotoxins as well as to monitor other DNA-damaging factors.