title: Comparison of Gene Expression Between Pediatric and Adult Gastric Mucosa with Helicobacter pylori Infection.
abstract: BACKGROUND
  Although Helicobacter pylori infection among adults is a major risk factor for the development of gastric cancer and initial infection with H. pylori may occur before 5 years of age, the direct effects of H. pylori infection since childhood on gastric mucosa are unknown. The aim of this study was to evaluate gene expression in the H. pylori-infected gastric mucosa of children.
  
  
  METHODS
  Gastric mucosal samples were obtained from 24 patients (12 adults and 12 children) who had undergone endoscopic evaluation of chronic abdominal complaints and were examined by the adult and pediatric gastroenterologists at Juntendo University Hospital. Six adult and pediatric patients with and six without H. pylori infection were enrolled. Their gastric mucosal samples obtained from the antrum and corpus were used for microarray, real-time polymerase chain reaction, and immunohistochemical analyses to examine the expression of inflammatory carcinogenic molecules.
  
  
  RESULTS
  The expression of inflammatory molecules was upregulated in the H. pylori-infected gastric mucosa from both adults and children. The expression of olfactomedin-4 was only upregulated in adult patients, while that of pim-2, regenerating islet-derived 3 alpha, lipocalin-2, and C-X-C motif chemokine ligand 13 was equally upregulated in the infected gastric mucosa of both adults and children.
  
  
  CONCLUSIONS
  Because several carcinogenic molecules are upregulated in H. pylori-infected gastric mucosa even in children, early eradication therapy from childhood may be beneficial to decrease the incidence of gastric cancer. Although increased expression of olfactomedin-4 can be important in suppressing gastric cancer in adults, the increase was not detected in children.
authors.affiliation: Department of Pediatrics and Adolescent Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Naho
authors.initials: N
authors.lastname: Obayashi
authors.affiliation: Department of Pediatrics and Adolescent Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Ohtsuka
authors.affiliation: Department of Pediatrics and Adolescent Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Hosoi
authors.affiliation: Department of Pediatrics and Adolescent Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Tamaki
authors.initials: T
authors.lastname: Ikuse
authors.affiliation: Department of Pediatrics and Adolescent Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Jimbo
authors.affiliation: Department of Pediatrics and Adolescent Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Yo
authors.initials: Y
authors.lastname: Aoyagi
authors.affiliation: Department of Pediatrics and Adolescent Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Fujii
authors.affiliation: Department of Pediatrics and Adolescent Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kudo
authors.affiliation: Department of Gastroenterology, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Asaoka
authors.affiliation: Department of Gastroenterology, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Mariko
authors.initials: M
authors.lastname: Hojo
authors.affiliation: Department of Gastroenterology, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Akihito
authors.initials: A
authors.lastname: Nagahara
authors.affiliation: Department of Gastroenterology, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Sumio
authors.initials: S
authors.lastname: Watanabe
authors.affiliation: Department of Pediatrics and Adolescent Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Shimizu
mesh_terms: D000293:Adolescent; D000328:Adult; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D016099:Endoscopy, Gastrointestinal; D005260:Female; D005753:Gastric Mucosa / Q000473:pathology*; D020869:Gene Expression Profiling; D016481:Helicobacter Infections / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D007564:Japan; D008297:Male; D046228:Microarray Analysis; D008875:Middle Aged; D060888:Real-Time Polymerase Chain Reaction
keywords: H. pylori infection; RT-PCR; gastric cancer; immunohistochemistry; microarray; pediatric