title: Helicobacter pylori potentiates epithelial:mesenchymal transition in gastric cancer: links to soluble HB-EGF, gastrin and matrix metalloproteinase-7.
abstract: OBJECTIVE
  Helicobacter pylori (H pylori) infection is a major risk factor in the development of distal gastric adenocarcinoma. Development of the invasive phenotype is associated with the phenomenon of epithelial:mesenchymal transition (EMT). Soluble heparin-binding epidermal growth factor (HB-EGF) has been implicated in this process. A study was undertaken to investigate the possibility that matrix metalloproteinase (MMP)-7 is upregulated in H pylori infection as a result of hypergastrinaemia, which may enhance shedding of HB-EGF and contribute towards EMT in gastric adenocarcinoma cell lines.
  
  
  METHODS
  Three gastric epithelial cell lines (AGS, MGLVA1 and ST16) were co-cultured with the pathogenic H pylori strain 60190 and non-pathogenic strain Tx30a in an in vitro infection model. Gene expression was quantified by real-time PCR, HB-EGF shedding by ELISA and protein expression by immunofluorescence or immunohistochemistry. The INS-GAS mouse, a transgenic mouse model of gastric carcinogenesis which overexpresses amidated gastrin, was used to investigate the in vivo relationship between HB-EGF, MMP-7, gastrin and EMT.
  
  
  RESULTS
  The pathogenic strain of H pylori significantly upregulated EMT-associated genes Snail, Slug and vimentin in all three gastric cell lines to a greater degree than the non-pathogenic strain. Pathogenic H pylori also upregulated HB-EGF shedding, a factor implicated in EMT, which was partially dependent on both gastrin and MMP-7 expression. Gastrin and MMP-7 siRNAs and MMP-7 neutralising antibody significantly reduced upregulation of HB-EGF shedding in H pylori infected gastric cell lines and reduced EMT gene expression. The effect of H pylori on EMT was also reversed by gastrin siRNA. Neutralisation of gastrin in the INS-GAS mouse model reduced expression of MMP-7, HB-EGF and key EMT proteins.
  
  
  CONCLUSIONS
  The upregulation of MMP-7 by pathogenic H pylori is partially dependent on gastrin and may have a role in the development of gastric cancer, potentially through EMT, by indirectly increasing levels of soluble HB-EGF.
authors.affiliation: Division of Pre-Clinical Oncology, University of Nottingham, Nottingham, UK.
authors.forename: Yinfei
authors.initials: Y
authors.lastname: Yin
authors.forename: Anna M
authors.initials: AM
authors.lastname: Grabowska
authors.forename: Philip A
authors.initials: PA
authors.lastname: Clarke
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Whelband
authors.forename: Karen
authors.initials: K
authors.lastname: Robinson
authors.forename: Richard H
authors.initials: RH
authors.lastname: Argent
authors.forename: Amanda
authors.initials: A
authors.lastname: Tobias
authors.forename: Rajendra
authors.initials: R
authors.lastname: Kumari
authors.forename: John C
authors.initials: JC
authors.lastname: Atherton
authors.forename: Susan A
authors.initials: SA
authors.lastname: Watson
mesh_terms: D000818:Animals; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D018920:Coculture Techniques; D004195:Disease Models, Animal; D004847:Epithelial Cells / Q000473:pathology; D005755:Gastrins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D015972:Gene Expression Regulation, Neoplastic; D016481:Helicobacter Infections / Q000378:metabolism* / Q000473:pathology; D016480:Helicobacter pylori / Q000472:pathogenicity*; D066257:Heparin-binding EGF-like Growth Factor; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D020783:Matrix Metalloproteinase 7 / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D059630:Mesenchymal Stem Cells / Q000473:pathology; D051379:Mice; D008822:Mice, Transgenic; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013274:Stomach Neoplasms / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D014407:Tumor Cells, Cultured; D015854:Up-Regulation; D014774:Virulence
chemical_list: D005755:Gastrins; C587883:HBEGF protein, human; C587884:Hbegf protein, mouse; D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins; D009363:Neoplasm Proteins; D034741:RNA, Small Interfering; C060932:MMP7 protein, human; D020783:Matrix Metalloproteinase 7