title: Radiosensitivity and repair kinetics of gamma-irradiated leukocytes from sporadic prostate cancer patients and healthy individuals assessed by alkaline comet assay.
abstract: Impaired DNA repair mechanism is one of the main causes of tumor genesis. Study of intrinsic radiosensitivity of cancer patients in a non-target tissue (e.g. peripheral blood) might show the extent of DNA repair deficiency of cells in affected individuals and might be used a predictor of cancer predisposition.
  
  
  
  Initial radiation-induced DNA damage (ratio of Tail DNA/Head DNA), dose-response curves and kinetics of DNA repair in leukocytes from healthy volunteers and prostate cancer patients were assessed using alkaline comet assay after exposure to 60Co gamma rays.
  
  
  
  Results showed that higher levels of baseline and gamma rays induced DNA damage in leukocytes of prostate cancer cases than in controls. A similar dose response was obtained for both groups. After a repair time of 24 h following in vitro irradiation, samples from the healthy individuals showed no residual DNA damage in their leukocytes, whereas prostate cancer patients revealed more than 20 percent. Although similar initial radiosensitivity was observed for both groups, the repair kinetics of radiation induced DNA damage of leukocytes from prostate cancer cases and healthy subjects were statistically different.
  
  
  
  These results support the hypothesis that men affected by prostate cancer may have a constitutional genomic instability.
authors.affiliation: Dept. of Medical Physics, Tarbiat Modares University, Tehran, Iran.|Dept. of Biochemistry and Biophysics, Mazandaran University of Medical Sciences, Sari, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Shahidi
authors.affiliation: Dept. of Medical Genetics, Tarbiat Modares University, Tehran, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Mozdarani
authors.affiliation: Institute of Medical Radiation Biology, University Hospital, Essen, Germany.
authors.forename: Wolfgang-Ulrich
authors.initials: WU
authors.lastname: Mueller
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D020552:Comet Assay / Q000379:methods*; D004249:DNA Damage; D004260:DNA Repair / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D006262:Health; D006801:Humans; D007700:Kinetics; D007962:Leukocytes / Q000473:pathology / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000473:pathology*; D011836:Radiation Tolerance / Q000528:radiation effects*