Oxidative Dna Damage and Repair in Chronic Atrophic Gastritis and Gastric Cancer

Background/Aims: Increased production of reactive oxygen species, which cause oxidative DNA damage, is considered to be related to gastric carcinogenesis. The aim of this research was to detect the 8-OHdG and the expression of hOGG1 and MnSOD, in human gastric mucosa with chronic atrophic gastritis (CAG) and gastric carcinoma (GC) comparing with normal controls (NC). Methodology: The level of 8-OHdG in gastric biopsy specimens was assessed with immunohistochemistry. The expression level of hOGG1 and MnSOD in gastric tissues was assessed with Western blot. Results: The 8-OHdG staining in CAG and GC mucosa was stronger than control (p<0.01). hOGG1 was expressed to a lower degree in GC and CAG when compared to the control group (both p<0.01) and the level of GC was even lower than CAG (p<0.05). MnSOD was expressed to a greater degree in GC group when compared to the control (p<0.05). Conclusions: CAG patients who express 8-OHdG highly should be monitored for the potentially occurrence of GC. The lower lever of hOGG1 in CAG and GC with higher level of 8-OHdG implies that hOGG1 is closely related to oxidative DNA damage and may lead to carcinoma. The increasing expression of MnSOD in the gastric mucosa may indicate the occurrence of gastric cancer.