title: Antioxidant enzyme levels in cases with gastrointesinal cancer.
abstract: 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).
  
  
  METHODS
  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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of General Surgery, Faculty of Medicine, Cukurova University, Adana, Turkey.
authors.forename: Yalcin
authors.initials: Y
authors.lastname: Kekec
authors.forename: Semra
authors.initials: S
authors.lastname: Paydas
authors.forename: Abdullah
authors.initials: A
authors.lastname: Tuli
authors.forename: Suzan
authors.initials: S
authors.lastname: Zorludemir
authors.forename: Gurhan
authors.initials: G
authors.lastname: Sakman
authors.forename: Gulsah
authors.initials: G
authors.lastname: Seydaoglu
mesh_terms: D000236:Adenoma / Q000378:metabolism* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000975:Antioxidants / Q000378:metabolism*; D018279:Carcinoma, Signet Ring Cell / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000378:metabolism* / Q000473:pathology; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D006801:Humans; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D055815:Young Adult
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D008315:Malondialdehyde; D005954:Glucosephosphate Dehydrogenase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase