Effect of Helicobacter pylori infection on the expression of DNA Mismatch Repair Protein

To determine the expression of DNA MMR proteins, including hMLH1 and hMSH2, in gastric epithelial cells of patients with or without H. pylori infected gastritis. Impairment of DNA mismatch repair (MMR) system is a known mechanism of carcinogenesis and tumor progression in both sporadic and hereditary human cancers.Patients and Fifty H.pylori-positive patients and 50 H.pylori-negative subjects were enrolled in the study. During endoscopy of patients with non-ulcer dyspepsia, 2 antral and 2 corpus biopsies were taken for histologic examination (Giemsa stain) and immunohistochemical staining on hMLH1 and hMSH2. The percentage of epithelial cell nuclei demonstrating positivity for hMLH1 staining was 84.14±7.32 in H.pylori-negative subjects in comparison of 73.34±10.10 in H.pylori-positive patients (p