Published online May 14, 2016. doi: 10.3748/wjg.v22.i18.4567
Peer-review started: December 4, 2015
First decision: December 31, 2015
Revised: January 19, 2016
Accepted: January 30, 2016
Article in press: January 30, 2016
Published online: May 14, 2016
Processing time: 154 Days and 5.3 Hours
AIM: To explore methylation of DAPK, THBS1, CDH-1, and p14 genes, and Helicobacter pylori (H. pylori) status in individuals harboring esophageal columnar metaplasia.
METHODS: Distal esophageal mucosal samples obtained by endoscopy and histologically diagnosed as gastric-type (non-specialized) columnar metaplasia, were studied thoroughly. DNA was extracted from paraffin blocks, and methylation status of death-associated protein kinase (DAPK), thrombospondin-1 (THBS1), cadherin-1 (CDH1), and p14 genes, was examined using a methyl-sensitive polymerase chain reaction (MS-PCR) and sodium bisulfite modification protocol. H. pylori cagA status was determined by PCR.
RESULTS: In total, 68 subjects (33 females and 35 males), with a mean age of 52 years, were included. H. pylori cagA positive was present in the esophageal gastric-type metaplastic mucosa of 18 individuals. DAPK, THSB1, CDH1, and p14 gene promoters were methylated by MS-PCR in 40 (58.8%), 33 (48.5%), 46 (67.6%), and 23 (33.8%) cases of the 68 esophageal samples. H. pylori status was associated with methylation of DAPK (P = 0.003) and THBS1 (P = 0.019).
CONCLUSION: DNA methylation occurs in cases of gastric-type (non-specialized) columnar metaplasia of the esophagus, and this modification is associated with H. pylori cagA positive infection.
Core tip: Columnar metaplasia of the esophagus, whether specialized or not, is a hallmark of gastroesophageal reflux disease. Current information suggests that intestinal metaplasia in the esophagus arises from gastric-type metaplasia. In this study, we have demonstrated that Helicobacter pylori (H. pylori) cagA+ can colonize esophageal gastric-type metaplastic mucosa, and that DNA methylation of tumor suppressor genes could be related to H. pylori cagA+ infection, which in turn, may predispose to precancerous lesions, including intestinal metaplasia.