title: Comparative analysis of antioxidative systems in malignant and benign brain tumours.
abstract: OBJECTIVE
  Comparison of redox conditions in malignant and benign tumours is essential for understanding the role of reactive oxygen species in the pathophysiology of aggressive cancer profiles. Here we compare antioxidative systems in highly malignant brain tumour - glioblastoma multiforme (GBM), and in meningioma, a benign brain tumour.
  
  
  METHODS
  Tumour tissues and blood of 67 GBM patients (mean age: 52.9 ± 11.5 years) and 67 meningioma patients (59.2 ± 10.2 years), and blood of 30 control subjects (50.8 ± 12.8 years) were analysed via biochemical assays.
  
  
  RESULTS
  Components of glutathione system, which is responsible for H2O2 removal, showed lower activity/level in GBM: glutathione peroxidase (GBM: 9.90 ± 0.22; meningioma: 11.78 ± 0.23 U/mg of proteins; P < 0.001), glutathione reductase (GBM: 3.83 ± 0.13; meningioma: 4.67 ± 0.11 U/mg of proteins; P < 0.001), and glutathione (GBM: 6.70 ± 0.12; meningioma: 7.58 ± 0.14 μmol/g of tissue; P < 0.001). In contrast, the rank order of glutathione reductase activity and glutathione level in erythrocytes was: GBM > meningioma > control. Superoxide dismutase and catalase activities were lower in the blood of cancer patients compared to controls.
  
  
  CONCLUSIONS
  Cells of malignant brain tumour show down-regulated antioxidative system which might result in increased levels of H2O2 compared to benign tumour tissue.
authors.forename: Vojislav
authors.initials: V
authors.lastname: Bogosavljević
authors.forename: Milica
authors.initials: M
authors.lastname: Bajčetić
authors.forename: Ivan
authors.initials: I
authors.lastname: Spasojević
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000378:metabolism*; D001932:Brain Neoplasms / Q000378:metabolism*; D016022:Case-Control Studies; D002374:Catalase / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D005909:Glioblastoma / Q000378:metabolism*; D005978:Glutathione / Q000097:blood / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D006801:Humans; D008297:Male; D008579:Meningioma / Q000378:metabolism*; D008875:Middle Aged; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005978:Glutathione
keywords: Erythrocytes; Glioblastoma; Glutathione peroxidase; Glutathione reductase; Hydrogen peroxide; Meningioma