title: Differential LINE-1 Hypomethylation of Gastric Low-Grade Dysplasia from High Grade Dysplasia and Intramucosal Cancer.
abstract: OBJECTIVE
  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.
authors.affiliation: Department of Internal Medicine, Cheju Halla General Hospital, Jeju, Korea.
authors.forename: Jeong Rok
authors.initials: JR
authors.lastname: Lee
authors.forename: Woo Chul
authors.initials: WC
authors.lastname: Chung
authors.forename: Jin Dong
authors.initials: JD
authors.lastname: Kim
authors.forename: Kang Moon
authors.initials: KM
authors.lastname: Lee
authors.forename: Chang Nyol
authors.initials: CN
authors.lastname: Paik
authors.forename: Sung Hoon
authors.initials: SH
authors.lastname: Jung
authors.forename: Ji Han
authors.initials: JH
authors.lastname: Jung
authors.forename: Yun Kyung
authors.initials: YK
authors.lastname: Lee
authors.forename: Sok Won
authors.initials: SW
authors.lastname: Han