1. Activation of EGFR and ERBB2 by Helicobacter pylori results in survival of gastric epithelial cells with DNA damage.
- Author
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Chaturvedi R, Asim M, Piazuelo MB, Yan F, Barry DP, Sierra JC, Delgado AG, Hill S, Casero RA Jr, Bravo LE, Dominguez RL, Correa P, Polk DB, Washington MK, Rose KL, Schey KL, Morgan DR, Peek RM Jr, and Wilson KT
- Subjects
- Animals, Apoptosis, Cell Line, Cell Survival, Cell Transformation, Neoplastic metabolism, Cell Transformation, Neoplastic pathology, Coculture Techniques, Colombia, Disease Progression, Enzyme Activation, Epithelial Cells microbiology, Epithelial Cells pathology, ErbB Receptors deficiency, ErbB Receptors genetics, Gastric Mucosa microbiology, Gastric Mucosa pathology, Gastritis enzymology, Gastritis microbiology, Gastritis pathology, Helicobacter Infections genetics, Helicobacter Infections microbiology, Helicobacter Infections pathology, Helicobacter pylori pathogenicity, Honduras, Humans, Metaplasia, Mice, Mice, Inbred C57BL, Mice, Knockout, Oxidoreductases Acting on CH-NH Group Donors metabolism, Phosphorylation, Precancerous Conditions enzymology, Precancerous Conditions microbiology, Precancerous Conditions pathology, Principal Component Analysis, Protein Multimerization, Receptor, ErbB-2 genetics, Signal Transduction, Stomach Neoplasms enzymology, Stomach Neoplasms microbiology, Stomach Neoplasms pathology, Tennessee, Polyamine Oxidase, DNA Damage, Epithelial Cells enzymology, ErbB Receptors metabolism, Gastric Mucosa enzymology, Helicobacter Infections enzymology, Helicobacter pylori metabolism, Receptor, ErbB-2 metabolism
- Abstract
Background & Aims: The gastric cancer-causing pathogen Helicobacter pylori up-regulates spermine oxidase (SMOX) in gastric epithelial cells, causing oxidative stress-induced apoptosis and DNA damage. A subpopulation of SMOX(high) cells are resistant to apoptosis, despite their high levels of DNA damage. Because epidermal growth factor receptor (EGFR) activation can regulate apoptosis, we determined its role in SMOX-mediated effects., Methods: SMOX, apoptosis, and DNA damage were measured in gastric epithelial cells from H. pylori-infected Egfr(wa5) mice (which have attenuated EGFR activity), Egfr wild-type mice, or in infected cells incubated with EGFR inhibitors or deficient in EGFR. A phosphoproteomic analysis was performed. Two independent tissue microarrays containing each stage of disease, from gastritis to carcinoma, and gastric biopsy specimens from Colombian and Honduran cohorts were analyzed by immunohistochemistry., Results: SMOX expression and DNA damage were decreased, and apoptosis increased in H. pylori-infected Egfr(wa5) mice. H. pylori-infected cells with deletion or inhibition of EGFR had reduced levels of SMOX, DNA damage, and DNA damage(high) apoptosis(low) cells. Phosphoproteomic analysis showed increased EGFR and erythroblastic leukemia-associated viral oncogene B (ERBB)2 signaling. Immunoblot analysis showed the presence of a phosphorylated (p)EGFR-ERBB2 heterodimer and pERBB2; knockdown of ErbB2 facilitated apoptosis of DNA damage(high) apoptosis(low) cells. SMOX was increased in all stages of gastric disease, peaking in tissues with intestinal metaplasia, whereas pEGFR, pEGFR-ERBB2, and pERBB2 were increased predominantly in tissues showing gastritis or atrophic gastritis. Principal component analysis separated gastritis tissues from patients with cancer vs those without cancer. pEGFR, pEGFR-ERBB2, pERBB2, and SMOX were increased in gastric samples from patients whose disease progressed to intestinal metaplasia or dysplasia, compared with patients whose disease did not progress., Conclusions: In an analysis of gastric tissues from mice and patients, we identified a molecular signature (based on levels of pEGFR, pERBB2, and SMOX) for the initiation of gastric carcinogenesis., (Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.)
- Published
- 2014
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