Aims: To assess oxidative DNA damage and total antioxidant capacity (TAC) in glioblastoma multiforme (GBM) and to compare the results with normal brain tissues.
Materials and methods: Oxidative DNA damage and TAC were evaluated in GBM tissues extracted from 26 patients and in normal brain tissues of 15 subjects who underwent autopsy within the first 4h of death. Oxidative DNA damage was assessed by measuring 8-hydroxy-2-deoxyguanosine (8-OH-dG) using the 8-OH-dG enzyme immunoassay kit, a quantitative assay for 8-OH-dG, and TAC was analysed using the ImAnOx colorimetric test system for the determination of antioxidative capacity. The results were compared between two groups and any correlation between 8-OH-dG and TAC was sought.
Results: The median level of TAC in GBM (121.5 nmol/g wet tissue) was remarkably lower than that in normal brain tissue (298 nmol/g wet tissue). The difference was statistically significant (P=0.00001). In contrast, oxidative DNA damage was significantly higher in patients with GBM (74.9 ng/g wet tissue) than in controls (34.71 ng/g wet tissue). Again, the difference was statistically significant (P=0.00001). We also found a negative correlation between oxidative DNA damage and TAC (P<0.001).
Conclusions: These findings indicate that the degree of oxidative DNA damage is increased and TAC is decreased in GBM. Oxidative DNA damage is correlated with the levels of TAC.