title: DNA oxidation and antioxidant status in breast cancer.
abstract: OBJECTIVE
  : Oxidant/antioxidant balance has been suggested as an important factor for initiation and progression of cancer. The objective of this study was to determine 8-hydroxydeoxyguanosine (8-OHdG) level as a marker of oxidative DNA damage, glutathione peroxidase (G-Px), and superoxide dismutase (SOD) activities as antioxidant activity, in sera from women with breast cancer.
  
  
  METHODS
  : Forty-nine patients with malign breast tumor were included in the study. Blood samples were collected before the surgical operation. Serum level of 8-OHdG was measured with a competitive enzyme-linked immunusorbent assay kit, SOD, and G-Px activities were measured by spectrophotometric kits.
  
  
  RESULTS
  : 8-Hydroxydeoxyguanosine level and SOD activity were found to be increased in breast cancer group as compared with control group. Glutathione peroxidase activity in the breast cancer group was lower than those in the control group. The ratio of 8-OHdG/G-Px in breast cancer patients was found to be higher than those in the controls. There were correlations between 8-OHdG and CA19-9 (r = 0.77; P < 0.01); age and G-Px (r = -0.84; P < 0.05) in the breast cancer group.
  
  
  CONCLUSIONS
  : Data show that serum levels of 8-OHdG and SOD activities are higher in patients with breast cancer. Glutathione peroxidase activity is lower in the breast cancer group. Increased ratio of 8-OHdG/G-Px in breast cancer patients is the evidence for impaired oxidant/ antioxidant balance in breast cancer.
authors.affiliation: Department of Biochemistry, and Department of General Surgery, Istanbul University Cerrahpasa Medical Faculty, Istanbul, Turkey.
authors.forename: Solen
authors.initials: S
authors.lastname: Himmetoglu
authors.forename: Yldz
authors.initials: Y
authors.lastname: Dincer
authors.forename: Yeliz E
authors.initials: YE
authors.lastname: Ersoy
authors.forename: Barş
authors.initials: B
authors.lastname: Bayraktar
authors.forename: Varol
authors.initials: V
authors.lastname: Celik
authors.forename: Tulay
authors.initials: T
authors.lastname: Akcay
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000328:Adult; D001943:Breast Neoplasms / Q000097:blood / Q000201:enzymology* / Q000473:pathology; D002277:Carcinoma / Q000097:blood / Q000201:enzymology* / Q000473:pathology; D016022:Case-Control Studies; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D005260:Female; D018226:Fibroadenoma / Q000097:blood / Q000201:enzymology* / Q000473:pathology; D005979:Glutathione Peroxidase / Q000378:metabolism; D006801:Humans; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology*; D010212:Papilloma / Q000097:blood / Q000201:enzymology* / Q000473:pathology; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000080242:8-Hydroxy-2'-Deoxyguanosine; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D003849:Deoxyguanosine