Persistent colonization of the human stomach with the Gram-negative bacterium Helicobacter pylori is associated with an increased risk for the development of gastric adenocarcinoma. Gastric cancer is the second leading cause of cancer-related death worldwide, and H. pylori has been classified as a type I carcinogen by the World Health Organization. Among H. pylori-infected persons, the risk of gastric cancer is determined by multiple variables, including characteristics of H. pylori strains, host genetic characteristics, and environmental factors. The long-term goal of this work is to define the mechanisms by which H. pylori infection can lead to gastric cancer, and to develop improved approaches for identifying individuals who have an increased risk for gastric cancer. In previous studies, we have shown that persons infected with GagA? positive H. pylori strains have an increased gastric cancer risk compared to persons infected with GagA? negative strains. H. pylori-induced gastric cancer in the Mongolian gerbil model is GagA-dependent, and we have shown that both a high-salt diet and a low-iron diet increase the risk of gastric cancer in H. pylori? infected gerbils. Furthermore, we have shown that exposure of H. pylori to high-salt conditions stimulates upregulation of GagA production. In this project, we propose to investigate further the regulation of H. pylori virulence by dietary factors that impact gastric cancer.
Aim 1 proposes to define the roles of three salt? regulated H. pylori outer membrane proteins (HopQ and two VacA-Iike proteins) in gastric cancer development. We will use multiple experimental approaches, including conventional cell culture, gastric organ culture and gastric organoid culture, and the Mongolian gerbil model of H. pylori-induced gastric cancer.
Aim 2 will identify shared .features of the pathways by which a high-salt diet and a low-iron diet augment gastric cancer risk in the H. pylori-infected gerbil model.
Aim 3 will analyze regulation of salt? responsive H. pylori genes in vivo and analyze adaptation of H. pylori to a carcinogenic gastric environment.
These aims will interdigitate with work proposed in Projects 1 and 2 (which each focus on H. pylori-induced epithelial cell alterations) and will utilize both the Gastric Histopathology and Proteomics Cores. These studies should lead to important advances in our understanding of the molecular mechanisms by which H. pylori infection and relevant dietary factors promote the development of gastric cancer. Ultimately, these studies should lead to advances in the prevention and therapy of malignancies that develop in the setting of chronic inflammation.
|Hardbower, Dana M; Singh, Kshipra; Asim, Mohammad et al. (2016) EGFR regulates macrophage activation and function in bacterial infection. J Clin Invest 126:3296-312|
|Riquelme, Ismael; Tapia, Oscar; Leal, Pamela et al. (2016) miR-101-2, miR-125b-2 and miR-451a act as potential tumor suppressors in gastric cancer through regulation of the PI3K/AKT/mTOR pathway. Cell Oncol (Dordr) 39:23-33|
|Gogoi, Mayuri; Datey, Akshay; Wilson, Keith T et al. (2016) Dual role of arginine metabolism in establishing pathogenesis. Curr Opin Microbiol 29:43-8|
|Gobert, Alain P; Wilson, Keith T (2016) The Immune Battle against Helicobacter pylori Infection: NO Offense. Trends Microbiol 24:366-76|
|Beceiro, S; Radin, J N; Chatuvedi, R et al. (2016) TRPM2 ion channels regulate macrophage polarization and gastric inflammation during Helicobacter pylori infection. Mucosal Immunol :|
|Zhao, Gang; Liu, Liping; Peek Jr, Richard M et al. (2016) Activation of Epidermal Growth Factor Receptor in Macrophages Mediates Feedback Inhibition of M2 Polarization and Gastrointestinal Tumor Cell Growth. J Biol Chem 291:20462-72|
|Peek Jr, Richard M (2016) New Biology to New Treatment of Helicobacter pylori-Induced Gastric Cancer. Dig Dis 34:510-6|
|Chen, Jinjing; Wang, Zhen; Hu, Xiangming et al. (2016) BET Inhibition Attenuates Helicobacter pylori-Induced Inflammatory Response by Suppressing Inflammatory Gene Transcription and Enhancer Activation. J Immunol 196:4132-42|
|Amieva, Manuel; Peek Jr, Richard M (2016) Pathobiology of Helicobacter pylori-Induced Gastric Cancer. Gastroenterology 150:64-78|
|Varga, Matthew G; Piazuelo, M Blanca; Romero-Gallo, Judith et al. (2016) TLR9 activation suppresses inflammation in response to Helicobacter pylori infection. Am J Physiol Gastrointest Liver Physiol 311:G852-G858|
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