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


METHODS
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.


RESULTS
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).


CONCLUSIONS
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.
Leung
Wai K
WK
Institute of Digestive Disease, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong. wkleung@cuhk.edu.hk
Man
Ellen P S
EP
Yu
Jun
J
Go
Minnie Y Y
MY
To
Ka-fai
KF
Yamaoka
Yoshio
Y
Cheng
Victoria Y Y
VY
Ng
Enders K W
EK
Sung
Joseph J Y
JJ
D000328:Adult; D015820:Cadherins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism*; D002471:Cell Transformation, Neoplastic; D019175:DNA Methylation; D005260:Female; D005753:Gastric Mucosa; D016481:Helicobacter Infections / Q000150:complications / Q000188:drug therapy*; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D011706:Pyloric Antrum / Q000737:chemistry; D013270:Stomach / Q000382:microbiology; D013274:Stomach Neoplasms / Q000209:etiology / Q000382:microbiology / Q000517:prevention & control
D015820:Cadherins