Impaired antioxidant enzyme functions with increased lipid peroxidation in epithelial ovarian cancer

We aimed to identify the possible role of oxidant–antioxidant status in epithelial ovarian cancer (EOC) by measuring (a) antioxidant enzyme (AOE) activities [total superoxide dismutase (SOD total ), manganese‐SOD (Mn‐SOD), copper,zinc‐SOD (Cu,Zn‐SOD), catalase (CAT) and glutathione peroxidase (GPx1)], (b) Mn‐SOD protein expression, (c) lipid peroxidation markers [malondialdehyde (MDA), 8‐epi‐prostaglandin‐F2α (8‐epi‐PGF2α)] and by evaluating the possible correlations between tumor biomarkers, reproductive hormone levels and all measured parameters, comprehensively. The data obtained from the patients with EOC (M, n  = 26) evaluated according to the histopathological/clinical characteristics of tumors and compared with data of healthy controls [C tissue (C1) and C blood/urine (C2), n  = 30, respectively). Significantly, low activities of tumor SOD total (52%), Mn‐SOD (42%), Cu,Zn‐SOD (55%); high activities of tumor and erythrocyte CAT (66%, 33% respectively) and tumor GPx1 (60%); high levels of tumor Mn‐SOD protein expression; tumor MDA (193%) and urinary 8‐epi‐PGF2α (179%) were observed in serous EOC tumors (M1, n  = 18) compared with controls ( P  < 0.05). However, higher levels of tumor MDA, Mn‐SOD protein expression and urinary 8‐epi‐PGF2α were observed along with lower tumor CAT activity in poorly differentiated or undifferentiated (grade 3, G 3) versus well or moderately well differentiated (grade 1‐2, G 1‐2) serous EOC tumors. Obtained data indicate the presence of a severe redox imbalance in EOC and draw attention to the criticial role of AOEs in the pathogenesis of the disease. © 2017 IUBMB Life, 69(10):802–813, 2017