Although the developmental stages of gastric
carcinoma are still not clear, the constantly generated reactive
oxygen and
nitrogen species (ROS/RNS) may contribute to the process of
carcinogenesis by interacting with
DNA.
8-oxoguanine DNA glycosylase-1 (OGG1) is an
enzyme involved in base excision repair of
8-oxoguanine that is one of the premutagenic lesions generated by ROS in
DNA. The bulky adducts, are recognized and repaired by nucleotid excision repair (NER)
enzymes, including
xeroderma pigmentosum C and D (XPC, XPD). Eligible 106
gastric cancer patients and 116
cancer-free individuals constituted the study and control groups, respectively. Association between OGG1 Ser326Cys, XPC Lys939Gln, XPD Lys751Gln polymorphisms and the susceptibility tho
cancer and the oxidative stress status were evaluated.
DNA was extracted from peripheral blood cells and genotypes were determined by using PCR-RFLP. Serum
nitric oxide,
albumin concentrations, total
antioxidant status and Helicobacter pylori
IgG were determined.
Serum albumin and
nitric oxide of
cancer patients were lower than that of the controls (P < 0.05). None of the evaluated polymorphisms or Helicobacter pylori
IgG seropositivity associated with increased risk of
gastric cancer, despite of the increased oxidative stress in
cancer patients.