Detection of DNA Double-strand Breaks through the Cell Cycle after Exposure to X-rays, Bleomycin, Etoposide and125IdUrd
- 1 January 1993
- journal article
- research article
- Published by Taylor & Francis in International Journal of Radiation Biology
- Vol. 64 (4) , 349-358
- https://doi.org/10.1080/09553009314551531
Abstract
Ionizing radiation-induced DNA double-strand breaks (DSBs) are generally more difficult to detect in S-phase cells than in cells from other phases of the cell cycle. To explore the basis for this observation, other double-strand breaking agents were examined: etoposide, bleomycin and 125IdUrd. DSBs induced by these agents in single cells in S, G1 or G2/M-phases of cell cycle were measured using the neutral comet assay. Regardless of the nature or location of the DSBs, Chinese hamster V79 cells with S-phase DNA content showed about 2–3 times less damage by all agents than cells with G1 or G2/M-phase DNA content. Residual protein content measured after lysis of S-phase cells embedded in agarose did not differ significantly from the protein content of asynchronous cells, and removal of proteins prior to irradiation did not enhance S phase migration. The number of DSBs, the physical nature of the DSB, or the presence of residual proteins, did not appear to influence migration. Therefore, we conclude that differences in DNA structure are responsible for reduced sensitivity for detecting DSBs in S-phase cells.Keywords
This publication has 36 references indexed in Scilit:
- The mode of action of 1-β-d-arabinofuranosylcytosine in inhibiting DNA repair; new evidence using a sensitive assay for repair DNA synthesis and ligation in permeable cellsMutation Research/DNA Repair, 1991
- Measurement of DNA Double-strand Breaks in CHO Cells at Various Stages of the Cell Cycle Using Pulsed Field Gel Electrophoresis: Calibration by Means of125I DecayInternational Journal of Radiation Biology, 1991
- Application of two‐dimensional gel electrophoresis in the study of cytoskeletal protein regulation during growth activation and differentiationElectrophoresis, 1990
- Matrix attachment regions are positioned near replication initiation sites, genes, and an interamplicon junction in the amplified dihydrofolate reductase domain of Chinese hamster ovary cells.Molecular and Cellular Biology, 1988
- The localization of replication origins on ARS plasmids in S. cerevisiaeCell, 1987
- Topoisomerase II: A specific marker for cell proliferation.The Journal of cell biology, 1986
- Topoisomerase II is a structural component of mitotic chromosome scaffolds.The Journal of cell biology, 1985
- Proteins tightly bound to HeLa cell DNA at nuclear matrix attachment sites.Molecular and Cellular Biology, 1983
- Type II DNA topoisomerases: Enzymes that can unknot a topologically knotted DNA molecule via a reversible double-strand breakCell, 1980
- The Nuclear Protein Matrix: Isolation, Structure, And FunctionsAdvances in Enzyme Regulation, 1976