No conflicts of interest were declared.
Comparison of CpG island hypermethylation and repetitive DNA hypomethylation in premalignant stages of gastric cancer, stratified for Helicobacter pylori infection†
Article first published online: 22 JUN 2009
Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The Journal of Pathology
Volume 219, Issue 4, pages 410–416, December 2009
How to Cite
Park, S.-Y., Yoo, E. J., Cho, N.-Y., Kim, N. and Kang, G. H. (2009), Comparison of CpG island hypermethylation and repetitive DNA hypomethylation in premalignant stages of gastric cancer, stratified for Helicobacter pylori infection. J. Pathol., 219: 410–416. doi: 10.1002/path.2596
- Issue published online: 9 NOV 2009
- Article first published online: 22 JUN 2009
- Accepted manuscript online: 22 JUN 2009 12:00AM EST
- Manuscript Accepted: 17 JUN 2009
- Manuscript Revised: 15 MAY 2009
- Manuscript Received: 30 DEC 2008
- chronic gastritis;
- CpG islands;
- DNA methylation;
- gastric cancer;
- Helicobacter pylori
CpG island hypermethylation and genomic DNA hypomethylation are found not only in gastric cancers but also in associated premalignant lesions. Helicobacter pylori infection induces aberrant CpG island hypermethylation in gastric mucosae. However, little is known about the relationship between H. pylori infection and aberrant methylation in premalignant lesions. The present study characterized methylation changes in a subset of genes and repetitive DNA elements (ALU, LINE-1, SAT2) and examined their relationship with H. pylori infection in premalignant lesions of gastric cancers. We performed MethyLight analysis of 25 genes and SAT2 and COBRA analysis of ALU and LINE-1 in 212 gastric tissue samples. H. pylori infection was closely associated with enhanced hypermethylation of CpG island loci in chronic gastritis samples, but this association was not found among intestinal metaplasias, gastric adenomas and gastric cancers. The number of methylated genes was greater in intestinal metaplasia and gastric adenoma samples than in chronic gastritis samples, regardless of H. pylori infection. Methylation of repetitive DNA elements in gastric lesions generally decreased with progression of the gastric lesion along the multistep carcinogenesis. No difference was noted in the number of methylated genes in chronic gastritis or intestinal metaplasia between gastric cancer patients and non-cancer subjects. In conclusion, we found that there was no enhanced CpG island hypermethylation in gastric cancer and premalignant lesions in association with H. pylori infection and our findings suggest that CpG island hypermethylation and repetitive DNA hypomethylation are enhanced with progression of the gastric lesion through the multistep carcinogenesis, regardless of the status of H. pylori infection. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.