title: Different microRNA expression levels in gastric cancer depending on Helicobacter pylori infection.
abstract: OBJECTIVE
  This study was conducted to identify microRNAs (miRNAs) that are differentially expressed in Helicobacter pylori-infected patients with an intestinal type of gastric cancer using miRNA microarray and to confirm the candidate miRNA expression levels.
  
  
  METHODS
  Total RNA was extracted from the cancerous and noncancerous regions of formalin-fixed, paraffin-embedded tissues of H. pylori-positive (n=8) or H. pylori-negative (n=8) patients with an intestinal type of gastric cancer. RNA expression was analyzed using a 3,523 miRNA profiling microarray based on the Sanger miRBase. Validation analysis was performed using TaqMan miRNA assays.
  
  
  RESULTS
  A total of 219 miRNAs in the aber-rant miRNA profiles across the miRNA microarray showed at least a 2-fold change differential expression in H. pylori-positive and H. pylori-negative cancer tissues. After candi-date miRNAs were selected using online miRNA databases, TaqMan miRNA assays confirmed that three miRNAs (miR-99b-3p, miR-564, and miR-638) were significantly increased in three H. pylori-positive cancer tissues compared to the H. pylori-negative cancer tissues. Additionally, four miRNAs (miR-204-5p, miR-338-5p, miR-375, and miR-548c-3p) were significantly increased in H. pylori-negative cancer tissues compared to H. pylori-positive cancer tissues.
  
  
  CONCLUSIONS
  miRNA expression in the intestinal type of H. pylori infection-dependent gastric cancer suggests that different gastric can-cer pathogenesis mechanisms could exist between H. pylori-positive and H. pylori-negative gastric cancer. Additional functional studies are required. (Gut Liver, 2015;9188-196).
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Hyun
authors.initials: H
authors.lastname: Chang
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam and Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Nayoung
authors.initials: N
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Ryoung Hee
authors.initials: RH
authors.lastname: Nam
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Yoon Jeong
authors.initials: YJ
authors.lastname: Choi
authors.affiliation: Department of Pathology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Hye Seung
authors.initials: HS
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Hyuk
authors.initials: H
authors.lastname: Yoon
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Cheol Min
authors.initials: CM
authors.lastname: Shin
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam and Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Young Soo
authors.initials: YS
authors.lastname: Park
authors.affiliation: NAR Center, Inc., Daejeon Oriental Hospital of Daejeon University, Daejeon, Korea.
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam and Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Dong Ho
authors.initials: DH
authors.lastname: Lee
mesh_terms: D000368:Aged; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D016481:Helicobacter Infections / Q000150:complications / Q000235:genetics*; D016480:Helicobacter pylori; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D035683:MicroRNAs / Q000378:metabolism*; D008875:Middle Aged; D012334:RNA, Neoplasm / Q000378:metabolism; D013274:Stomach Neoplasms / Q000150:complications / Q000235:genetics*
chemical_list: D035683:MicroRNAs; D012334:RNA, Neoplasm
keywords: Gastric carcinogenesis; Helicobacter pylori; Mi-croarray; MicroRNAs; TaqMan miRNA assays