Antioxidant enzyme levels in cases with gastrointesinal cancer

The aim is to evaluate the antioxidant enzyme levels in tumoral tissues and accompanying normal tissues in gastrointestinal cancer; and compare the colorectal cancer (CRC) with gastric cancer (GC). Method: Antioxidant enzymes including glutathione reductase (GR), glutathione peroxidase (GPX), superoxide dismutase (SOD), malondialdehyde (MDA) and glucose 6 phosphate dehyrogenase (G6PD) which are important for anti-oxidant functions were evaluated in fresh tumor tissues and adjacent normal tissues obtained from a total of 58 patients. Results: All the enzyme levels were higher in tumoral tissues compared to normal tissue from non-cancerous disease. There was not a significant difference for enzyme levels between CRC and GC groups except GPx. GPx activity tended to be higher in cases without serosal involvement (SI), and this activity was higher in cases without lymph node (LN) involvement in normal tissue (p=0.012). MDA activity was higher in cases without serosal involvement compared to with SI groups in tumor tissue (p=0.050). G6PD activity in normal tissue was higher in cases with serosal involvement and LN involvement (p=0.064. 0.046, respectively). GR activity was higher in signet ring cell cancer (SRC) than adeno cancer. In GC, G6PD activity in tumor was tended to be higher in undifferentiated cancer (p=0.071). Conclusion: The antioxidant enzymes activities such as GPX. SOD, G6PD, MDA and GR were found to be related with malignant phenotype in gastrointestinal cancers. We need further studies to understand the biologic and clinical importance of these enzymes in GI cancers. (C) 2009 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.