Gut Liver.  2011 Jun;5(2):149-153.

Differential LINE-1 Hypomethylation of Gastric Low-Grade Dysplasia from High Grade Dysplasia and Intramucosal Cancer

• Lee JR
• Chung WC
• Kim JD
• Lee KM
• Paik CN
• Jung SH
• Jung JH
• Lee YK
• Han SW

Abstract

BACKGROUND/AIMS
Gastric epithelial dysplasia is considered a precancerous lesion with a variable clinical course. There is disagreement, however, regarding histology-based diagnoses, which has led to confusion in choosing a therapeutic plan. New objective markers are needed to determine which lesions progress to true malignancy. We measured LINE-1 methylation levels, which have been reported to strongly correlate with the global methylation level in gastric epithelial dysplasia and intramucosal cancer.
METHODS
A total of 145 tissue samples were analyzed by two histopathologists. All tissues were excised by therapeutic endoscopic mucosal resection and paired with adjacent normal tissue samples. A modified long interspersed nucleotide elements-combined bisulfite restriction analysis (COBRA-LINE-1) method was used.
RESULTS
Gastric epithelial dysplasia and intramucosal cancer tissues had significantly lower levels of LINE-1 methylation than adjacent normal gastric tissues. High-grade dysplasia and intramucosal cancer were distinguishable from low-grade dysplasia based on LINE-1 methylation levels. Furthermore, the distinction could be determined with high sensitivity and specificity, as shown by the receiver operating characteristic (ROC) curve (AUC, 0.82; 95% confidence interval, 0.74 to 0.88).
CONCLUSIONS
LINE-1 methylation levels may provide a diagnostic tool for identifying high-grade dysplasia and intramucosal cancer.

Keyword

LINE-1 methylation; Gastric epithelial dysplasia; Intramucosal cancer

MeSH Terms

Methylation
ROC Curve
Sensitivity and Specificity
Sulfites
Sulfites