title: DNA damage induction and tumour cell radiosensitivity: PFGE and halo measurements.
abstract: OBJECTIVE
  To test whether induction of DNA damage is correlated with tumour-cell radiosensitivity.
  
  
  METHODS
  Initial DNA damage caused by X-irradiation was measured in ten human tumour cell lines, which largely differed in radiosensitivity, using either the pulsed-field gel electrophoresis assay or the halo technique.
  
  
  RESULTS
  None of the parameters of DNA damage correlated with any parameter of cellular radiosensitivity. This was not only true when the analysis was performed on all data but also when the analysis was performed after separating the cell lines into radioresistant and sensitive groups. Even when differences in chromosome number, ploidy and cell cycle distribution were taken into account, no significant correlations were obtained.
  
  
  CONCLUSIONS
  Contrary to previous suggestions, differences in the number of double-strand breaks induced or chromatin-related 'presentation' of DNA lesions, measured by pulsed-field gel electrophoresis or halo respectively, are generally not the dominant factors determining tumour-cell radiosensitivity.
authors.affiliation: Department of Radiobiology, University of Groningen, The Netherlands.
authors.forename: E C
authors.initials: EC
authors.lastname: Woudstra
authors.forename: C
authors.initials: C
authors.lastname: Driessen
authors.forename: A W
authors.initials: AW
authors.lastname: Konings
authors.forename: H H
authors.initials: HH
authors.lastname: Kampinga
mesh_terms: D002470:Cell Survival / Q000528:radiation effects; D004249:DNA Damage; D004273:DNA, Neoplasm / Q000378:metabolism* / Q000528:radiation effects*; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods; D006801:Humans; D008856:Microscopy, Fluorescence; D009369:Neoplasms / Q000532:radiotherapy*; D011836:Radiation Tolerance; D014407:Tumor Cells, Cultured
chemical_list: D004273:DNA, Neoplasm