Oxidative DNA damage accumulation in gastric carcinogenesis

Area of Science:

• Gastroenterology and Oncology
• Molecular Biology
• Pathology

Background:

• Gastric carcinogenesis is a complex process driven by chronic inflammation.
• Oxidative stress and DNA damage are implicated in the multistep development of gastric cancer.

Purpose of the Study:

• To investigate the role of free radical-mediated oxidative DNA damage in gastric carcinogenesis.
• To quantify levels of 8-hydroxydeoxyguanosine (8OHdG) and thiobarbituric acid reactive substances (TBARS) in gastric biopsy specimens.

Main Methods:

• Eighty-eight patients were categorized into groups: chronic non-atrophic gastritis, atrophic gastritis, gastric cancer, and controls.
• Assessed 8OHdG and TBARS concentrations using HPLC and fluorimetric assays, respectively.
• Semiquantitatively scored intestinal metaplasia, Helicobacter pylori infection, and disease activity.

Main Results:

• Significantly higher 8OHdG concentrations were observed in atrophic gastritis, severe disease activity, intestinal metaplasia, and H. pylori infection.
• 8OHdG levels correlated strongly with the presence and severity of H. pylori infection (r=0.53, p=0.002).
• TBARS concentrations were elevated in atrophic gastritis, though not significantly.

Conclusions:

• Chronic gastritis is associated with accumulated oxidative DNA damage, possessing mutagenic and carcinogenic potential.
• Helicobacter pylori infection is identified as the primary driver of DNA adduct formation in this context.