title: Gastrokine 1 expression in the human gastric mucosa is closely associated with the degree of gastritis and DNA methylation.
abstract: OBJECTIVE
  Gastrokine 1 plays an important role in gastric mucosal defense. Additionally, the Gastrokine 1-miR-185-DNMT1 axis has been shown to suppress gastric carcinogenesis through regulation of epigenetic alteration. Here, we investigated the effects of Gastrokine 1 on DNA methylation and gastritis.
  
  
  METHODS
  Expression of Gastrokine 1, DNMT1, EZH2, and c-Myc proteins, and the presence of Helicobacter pylori CagA protein were determined in 55 non-neoplastic gastric mucosal tissue samples by western blot analysis. The CpG island methylation phenotype was also examined using six markers (p16, hMLH1, CDH1, MINT1, MINT2 and MINT31) by methylation-specific polymerase chain reaction. Histological gastritis was assessed according to the updated Sydney classification system.
  
  
  RESULTS
  Reduced Gastrokine 1 expression was found in 20 of the 55 (36.4%) gastric mucosal tissue samples and was closely associated with miR-185 expression. The Gastrokine 1 expression level was inversely correlated with that of DNMT1, EZH2, and c-Myc, and closely associated with the degree of gastritis. The H. pylori CagA protein was detected in 26 of the 55 (47.3%) gastric mucosal tissues and was positively associated with the expression of DNMT1, EZH2, and c-Myc. In addition, 30 (54.5%) and 23 (41.9%) of the gastric mucosal tissues could be classified as CpG island methylation phenotype-low and CpG island methylation phenotype-high, respectively. Reduced expression of Gastrokine 1 and miR-185, and increased expression of DNMT1, EZH2, and c-Myc were detected in the CpG island methylation phenotype-high gastric mucosa.
  
  
  CONCLUSIONS
  Gastrokine 1 has a crucial role in gastric inflammation and DNA methylation in gastric mucosa.
authors: Department of Pathology, The Catholic University of Korea, School of Medicine, Seoul, Korea.
authors: Won Suk
authors: WS
authors: Choi
authors: Department of General Surgery, The Catholic University of Korea, School of Medicine, Seoul, Korea.
authors: Ho Suk
authors: HS
authors: Seo
authors: Department of General Surgery, The Catholic University of Korea, School of Medicine, Seoul, Korea.
authors: Kyo Young
authors: KY
authors: Song
authors: Department of Pathology, The Catholic University of Korea, School of Medicine, Seoul, Korea.
authors: Jung Hwan
authors: JH
authors: Yoon
authors: Department of Pathology, The Catholic University of Korea, School of Medicine, Seoul, Korea.
authors: Olga
authors: O
authors: Kim
authors: Department of Pathology, The Catholic University of Korea, School of Medicine, Seoul, Korea.
authors: Suk Woo
authors: SW
authors: Nam
authors: Department of Pathology, The Catholic University of Korea, School of Medicine, Seoul, Korea.
authors: Jung Yong
authors: JY
authors: Lee
authors: Department of Pathology, The Catholic University of Korea, School of Medicine, Seoul, Korea.
authors: Won Sang
authors: WS
authors: Park
keywords: CagA protein; DNA methylation; Gastric mucosa; Gastrokine 1; microRNA-185