Helicobacter pylori potentiates epithelial:mesenchymal transition in gastric cancer: links to soluble HB-EGF, gastrin and matrix metalloproteinase-7.
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.
Yin
Yinfei
Y
Division of Pre-Clinical Oncology, University of Nottingham, Nottingham, UK.
Grabowska
Anna M
AM
Clarke
Philip A
PA
Whelband
Elisabeth
E
Robinson
Karen
K
Argent
Richard H
RH
Tobias
Amanda
A
Kumari
Rajendra
R
Atherton
John C
JC
Watson
Susan A
SA
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
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