Korean J Med.  2006 Jul;71(1):17-23.

Microsatellite instability in mongolian gerbils induced by Helicobacter pylori

• Park DI
• Kim MK
• Kim JJ
• Yoo TW
• Park JH
• Kim HJ
• Cho YK
• Sohn CI
• Jeon WK
• Kim BI

Abstract

BACKGROUND: During Helicobacter pylori (HP) gastritis, the organisms cause an impairment of DNA repair that results in accumulation of mutations in the genome of epithelial cells and an increased risk of gastric carcinoma. The aim of this study was to determine whether microsatellite instability (MSI) could be induced by chronic HP infection in the Mongolian gerbil model.
METHODS
Seven-weeks old, specific pathogen-free male Mongolian gerbils were infected with the HP strain CA20. They were sacrificed at the each time points (1, 2, 3, 6, 9, 12 months). Areas of gastritis were carefully microdissected. DNA from tissues was analyzed for the presence of MSI by genomic DNA amplification with five gerbil microsatellite markers per sample. Gerbil markers labelled with Fam or Hex were obtained to perform MSI analysis using the 310 Genetic Analyzer.
RESULTS
MSI was more frequent in the area of gastritis than in that of normal (p<0.05). Six showed MSI-low and one showed MSI-high within the area of gastritis (p<0.05).
CONCLUSIONS
This study shows that chronic HP infection in the Mongolian gerbil induces MSI. This finding indicates that HP infection causes a decrease in DNA MMR proteins in epithelial cells of the stomach that may reach critically low levels, allowing for the accumulation of mutations such as those seen in microsatellite regions.

Keyword

Microsatellite instability; Helicobacter pylori; Animal model

MeSH Terms

DNA
DNA Repair
Epithelial Cells
Gastritis
Genome
Gerbillinae*
Helicobacter pylori*
Helicobacter*
Humans
Male
Microsatellite Instability*
Microsatellite Repeats*
Models, Animal
Stomach
DNA