Rejoining of DNA double-strand breaks in Ku80-deficient mouse fibroblasts Journal Article


Authors: Wachsberger, P. R.; Li, W. H.; Guo, M.; Chen, D.; Cheong, N.; Ling, C. C.; Li, G.; Iliakis, G.
Article Title: Rejoining of DNA double-strand breaks in Ku80-deficient mouse fibroblasts
Abstract: The role of Ku80 in the repair of DNA double-strand breaks (DSBs) was examined in fibroblasts derived from a Ku80 knockout mouse model described by Nussenzweig et al. (Nature 382, 551-555, 1996). Primary fibroblasts from Ku80(+/+) and Ku80(-/-) mice were immortalized by transfection with plasmids containing either the human MYC proto-oncogene or the Simian virus 40 (SV40) T antigen and were used to measure induction and rejoining of DSBs after exposure to ionizing radiation. The number of DSBs in the cells was quantified by either asymmetric field-inversion gel electrophoresis (AFIGE) or clamped homogeneous electrical-field gel electrophoresis (CHEF). The latter method was introduced for a more reliable quantification of repair even when DNA degradation occurs in a fraction of the irradiated cell population during the postirradiation incubation time. The results confirm that Ku80-deficient mouse fibroblasts are sensitive to ionizing radiation and demonstrate that the increased radiosensitivity may result from a deficiency in DSB rejoining. The results further indicate that unless techniques are employed that allow for distinction between DNA degradation and DNA repair, erroneous conclusions may be drawn regarding the potential of cells to repair DSBs.
Keywords: nonhuman; animal cell; dna repair; animalia; dna strand breakage; double stranded dna; fibroblast; simian virus 40; ionizing radiation; dna determination; gel electrophoresis; cell immortalization; simiae; simian virus; dna transfection; human; priority journal; article
Journal Title: Radiation Research
Volume: 151
Issue: 4
ISSN: 0033-7587
Publisher: Radiation Research Society  
Date Published: 1999-04-01
Start Page: 398
End Page: 407
Language: English
DOI: 10.2307/3579826
PUBMED: 10190491
PROVIDER: scopus
DOI/URL:
Notes: Article -- Export Date: 16 August 2016 -- Source: Scopus
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MSK Authors
  1. Gloria C Li
    132 Li
  2. C Clifton Ling
    331 Ling
  3. Min Guo
    11 Guo