Daza H., P. and Schussler, H. and McMillan, T. J. and Girod, S. C. and Pfeiffer, P. (1997) Radiosensitivity and double-strand break rejoining in tumorigenic and non-tumorigenic human epithelial cell lines. International Journal of Radiation Biology, 72 (1). pp. 91-100. ISSN 1362-3095Full text not available from this repository.
Radiosensitivity and repair of DNA damage induced by ionizing radiation and restriction enzymes were investigated in three human epithelial cell lines: two tumorigenic squamous carcinoma cell lines (SCC-4 and SCC-25), and a nontumorigenic epidermal keratinocyte cell line (RHEK-1). Sensitivity to ionizing radiation was determined using a clonogenic cell survival assay, which showed SCC-4 to be more radiosensitive than SCC-25 and RHEK-1, which in turn displayed about equal sensitivity. Using DNA precipitation under alkaline conditions for the analysis of induction and repair of DNA single-strand breaks (ssb), an increased level of ssb induction was found for SCC-4 while the efficiency of ssb repair was about equal in all three cell lines. Using pulsed-field gel electrophoresis (PFGE) for the measurement of induction and repair of DNA double-strand breaks (dsb), no consistent differences were detected between the three cell lines. A plasmid reconstitution assay was used to determine the capacity to rejoin restriction enzyme-induced dsb in whole-cell extracts prepared from the three cell lines. In these experiments, dsb rejoining was shown to be significantly reduced in the most radiosensitive SCC-4 cell line while it was about equal in RHEK-1 and SCC-25. The results indicate that plasmid reconstitution in cell-free extracts is a sufficiently sensitive assay to detect differences in repair capacity among tumour cell lines of different radiosensitivity which remain undetectable by DNA precipitation and PFGE.
|Journal or Publication Title:||International Journal of Radiation Biology|
|Subjects:||Q Science > QH Natural history > QH301 Biology|
|Departments:||Faculty of Science and Technology > Lancaster Environment Centre|
|Deposited By:||Professor Trevor McMillan|
|Deposited On:||12 May 2008 15:55|
|Last Modified:||26 Jul 2012 18:26|
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