Effects of Helicobacter pylori eradication on methylation status of E-cadherin gene in noncancerous stomach

Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, 00, Hong Kong
Clinical Cancer Research (Impact Factor: 8.72). 06/2006; 12(10):3216-21. DOI: 10.1158/1078-0432.CCR-05-2442
Source: PubMed


Promoter hypermethylation of E-cadherin plays an important role on gastric cancer development. Whereas E-cadherin methylation was frequently detected in the stomach of Helicobacter pylori-infected individuals, we tested whether eradication of H. pylori alters the methylation status of the noncancerous gastric epithelium.
Endoscopic biopsies were taken from the antrum and corpus of H. pylori-infected subjects without gastric cancer. Presence of methylated E-cadherin sequences in the gastric specimens was detected by methylation-specific PCR. Bisulfite DNA sequencing was done to determine the topographical distribution and changes in methylation profiles with H. pylori eradication.
Among the 28 H. pylori-infected subjects (median age, 44.5 years), 15 (53.6%) had E-cadherin methylation detected in stomach at baseline. Discordant methylation patterns between the antrum and corpus were noted in six patients. One year after successful H. pylori eradication, there was a significant reduction in the methylation density of the promoter region and exon 1 of the E-cadherin gene as detected by bisulfite DNA sequencing (P < 0.001).
Promoter methylation in E-cadherin was frequently detected in the stomach of H. pylori-infected individuals. Eradication of H. pylori might possibly reduce the methylation density in E-cadherin gene and the chance of subsequent neoplastic transformation.

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    Molecular Cancer 09/2009; 8(1):63. DOI:10.1186/1476-4598-8-63 · 4.26 Impact Factor
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    • "Epigenetic silencing of tumour-related genes due to CpG island hypermethylation has emerged as one of the most important alternations in gastric cancer development (Leung et al, 2001; Yu et al, 2003). We have previously shown that tumour-related genes including E-cadherin, p15, and p16 were frequently methylated in gastric cancer (Leung et al, 2001) as well as in pre-malignant gastric lesions (Leung et al, 2006), suggesting dysregulation in CpG-island methylation is likely to be involved in the early gastric carcinogenesis process. Wnt proteins are secreted signalling factors with multiple functions in development and tumourigenesis (Polakis 2007). "
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