This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Olive, P. L. Articles by Banáth, J. P. Search for Related Content PubMed PubMed Citation Articles by Olive, P. L. Articles by Banáth, J. P.

DNA Double-Strand Breaks Measured in Individual Cells Subjected to Gel Electrophoresis¹

British Columbia Cancer Research Centre, Vancouver, British Columbia, Canada V5Z 1L3

Microscopic examination of individual mammalian cells embedded in agarose, subjected to electrophoresis, and stained with a fluorescent DNA-binding dye provides a novel way of measuring DNA damage and more importantly, of assessing heterogeneity in DNA damage within a mixed population of cells. With this method, DNA double-strand breaks can be detected in populations of cells exposed to X-ray doses as low as 5 Gy. The radiation dose-response relationship for initial formation of double-strand breaks was identical for cell lines irradiated in G₁, regardless of their sensitivity to killing by ionizing radiation. However, for cells irradiated in S phase, DNA migration was significantly reduced. For Chinese hamster V79 cells, Chinese hamster ovary cells, WiDr human colon carcinoma cells, and L5178Y-R mouse lymphoblastoid cells, S-phase DNA appeared to be about 3 times less sensitive to X-ray damage than DNA from other phases of the cell cycle. However, for the very radiosensitive L5178Y-S cells, the migration of replicating DNA was reduced only slightly. For Chinese hamster V79 and Chinese hamster ovary cells, damage was repaired at a similar rate in all cells of the population, and 85% of the breaks were rejoined within 2 h after irradiation. The radiosensitive L5178Y-S cells repaired damage more slowly than V79 or Chinese hamster ovary cells; 2 h after exposure to 50 Gy, approximately 50% of the damage was still present.

¹ This work was supported by a grant from the National Cancer Institute of Canada.

² To whom requests for reprints should be addressed.

Received 3/19/91. Accepted 6/14/91.

This article has been cited by other articles:

				K. Araki, S. M. Ahmad, G. Li, D. A. Bray Jr, K. Saito, D. Wang, U. Wirtz, S. Sreedharan, B. W. O'Malley Jr, and D. Li Retinoblastoma RB94 Enhances Radiation Treatment of Head and Neck Squamous Cell Carcinoma Clin. Cancer Res., June 1, 2008; 14(11): 3514 - 3519. [Abstract] [Full Text] [PDF]

				T. Tanaka, A. Munshi, C. Brooks, J. Liu, M. L. Hobbs, and R. E. Meyn Gefitinib Radiosensitizes Non-Small Cell Lung Cancer Cells by Suppressing Cellular DNA Repair Capacity Clin. Cancer Res., February 15, 2008; 14(4): 1266 - 1273. [Abstract] [Full Text] [PDF]

				M. Briegert and B. Kaina Human Monocytes, but not Dendritic Cells Derived from Them, Are Defective in Base Excision Repair and Hypersensitive to Methylating Agents Cancer Res., January 1, 2007; 67(1): 26 - 31. [Abstract] [Full Text] [PDF]

				S. Ray, K. R. Atkuri, D. Deb-Basu, A. S. Adler, H. Y. Chang, L. A. Herzenberg, and D. W. Felsher MYC Can Induce DNA Breaks In vivo and In vitro Independent of Reactive Oxygen Species. Cancer Res., July 1, 2006; 66(13): 6598 - 6605. [Abstract] [Full Text] [PDF]

				Y. Seo, T. Yan, J. E. Schupp, K. Yamane, T. Radivoyevitch, and T. J. Kinsella The Interaction between Two Radiosensitizers: 5-Iododeoxyuridine and Caffeine Cancer Res., January 1, 2006; 66(1): 490 - 498. [Abstract] [Full Text] [PDF]

				K. Trenz, P. Schutz, and G. Speit Radiosensitivity of lymphoblastoid cell lines with a heterozygous BRCA1 mutation is not detected by the comet assay and pulsed field gel electrophoresis Mutagenesis, March 1, 2005; 20(2): 131 - 137. [Abstract] [Full Text] [PDF]

				K. E. Young, W. A. Robbins, L. Xun, D. Elashoff, S. A. Rothmann, and S. D. Perreault Evaluation of Chromosome Breakage and DNA Integrity in Sperm: An Investigation of Remote Semen Collection Conditions J Androl, November 1, 2003; 24(6): 853 - 861. [Abstract] [Full Text] [PDF]

				S. Yasuhara, Y. Zhu, T. Matsui, N. Tipirneni, Y. Yasuhara, M. Kaneki, A. Rosenzweig, and J.A. J. Martyn Comparison of Comet Assay, Electron Microscopy, and Flow Cytometry for Detection of Apoptosis J. Histochem. Cytochem., July 1, 2003; 51(7): 873 - 885. [Abstract] [Full Text] [PDF]

				A. Franchitto, J. Oshima, and P. Pichierri The G2-phase Decatenation Checkpoint Is Defective in Werner Syndrome Cells Cancer Res., June 15, 2003; 63(12): 3289 - 3295. [Abstract] [Full Text] [PDF]

				S.M. Duty, N.P. Singh, L. Ryan, Z. Chen, C. Lewis, T. Huang, and R. Hauser Reliability of the comet assay in cryopreserved human sperm Hum. Reprod., May 1, 2002; 17(5): 1274 - 1280. [Abstract] [Full Text] [PDF]

				P. Pichierri, A. Franchitto, P. Mosesso, and F. Palitti Werner's Syndrome Protein Is Required for Correct Recovery after Replication Arrest and DNA Damage Induced in S-Phase of Cell Cycle Mol. Biol. Cell, August 1, 2001; 12(8): 2412 - 2421. [Abstract] [Full Text] [PDF]

				J. Lips and B. Kaina DNA double-strand breaks trigger apoptosis in p53-deficient fibroblasts Carcinogenesis, April 1, 2001; 22(4): 579 - 585. [Abstract] [Full Text] [PDF]

				A. D. Badley, A. A. Pilon, A. Landay, and D. H. Lynch Mechanisms of HIV-associated lymphocyte apoptosis Blood, November 1, 2000; 96(9): 2951 - 2964. [Abstract] [Full Text] [PDF]

				Q. Q. Pu and W. R. Bezwoda Induction of Alkylator (Melphalan) Resistance in HL60 Cells Is Accompanied by Increased Levels of Topoisomerase II Expression and Function Mol. Pharmacol., July 1, 1999; 56(1): 147 - 153. [Abstract] [Full Text]

				D. B. Sawyer, R. Fukazawa, M. A. Arstall, and R. A. Kelly Daunorubicin-Induced Apoptosis in Rat Cardiac Myocytes Is Inhibited by Dexrazoxane Circ. Res., February 19, 1999; 84(3): 257 - 265. [Abstract] [Full Text] [PDF]

				L. BENITEZ-BRIBIESCA and P. SANCHEZ-SUAREZ Oxidative Damage, Bleomycin, and Gamma Radiation Induce Different Types of DNA Strand Breaks in Normal Lymphocytes and Thymocytes: A Comet Assay Study Ann. N.Y. Acad. Sci., January 1, 1999; 887(1): 133 - 149. [Abstract] [Full Text] [PDF]