Project description:Helicobacter pylori (H. pylori) is a human pathogen that infects almost half of the world’s population. Infection with H. pylori is frequently associated with chronic gastritis and can even lead to gastric and duodenal ulcers and gastric cancer. Although the persistent colonization of H. pylori and the development of H. pylori-associated gastritis remain poorly understood, it is believed that, in gastric mucosa, the modulated gastric epithelial cells (GECs) by H. pylori are key contributors. We used microarrays to detail the global programme of gene expression in Helicobacter pylori infected-gastric epithelial cell line AGS cells and identified up-regulated genes induced by Helicobacter pylori infection.
Project description:Helicobacter pylori (H. pylori) infection is a key initiating factor in the Correa cascade of gastric carcinogenesis, but the comprehensive understanding of the pathogenic mechanisms underlying H. pylori-induced GC remains elusive. Here, we generated a single-cell atlas of gastric tumorigenesis comprising 18 specimens of gastritis, intestinal metaplasia and gastric cancer (GC) with or without H. pylori infection. We identified 48 distinct cell subpopulations including novel rare subtypes, and revealed the influence of H. pylori infection on cellular heterogeneity across neoplastic lesions.
Project description:Helicobacter pylori (H.pylori) infection is an important factor in the occurrence of human gastric diseases, but its pathogenic mechanism is not clear. N6-methyladenosine (m6A) is the most prevalent reversible methylation modification in mammalian RNA and it plays a crucial role in controlling many biological processes. We used MeRIP-seq technology to sequence the GES-1 cells infected with Helicobacter pylori(H. pylori) for 48 h.
Project description:Gastric intestinal metaplasia (GIM) is an important precancerous lesion in intestinal-type gastric cancer, with persistent Helicobacter pylori (H. pylori) infection inducing the condition. In a previous study, we identified a new H. pylori virulence factor, SlyD. However, its mode of action between GIM was unknown. Our findings offer clues to reveal the molecular mechanism of H.pylori infection-associated gastric intestinal metaplasia, and provides the mechanism of a novel H. pylori virulence factor SlyD in gastric precancerous disease.
Project description:Helicobacter pylori (H. pylori) is a type of pathogen in humans that has infected nearly half of the population worldwide. Infections with H. pylori are typically associated with chronic gastritis and may even lead to gastric and duodenal ulcers and stomach cancer. While the mechanisms behind persistent colonization by H. pylori and the development of gastritis associated with it remain unclear, it is generally believed that the gastric epithelial cells (GECs) modulated by H. pylori in the gastric mucosa play a crucial role. We extensively studied the global gene expression patterns in H. pylori-infected AGS cells, a line of gastric epithelial cells, and identified genes that show increased expression upon infection with H. pylori.
Project description:Helicobacter pylori infection can induce gastric pathologies ranging from chronic gastritis to peptic ulcers and gastric cancer. Individuals´ response to H. pylori infection is complex and it depends on a combination of environmental factors, genetic background, host response and strain virulence. The pathway towards gastric cancer is a sequence of events known as the Correa's model of gastric carcinogenesis, a stepwise inflammatory process from normal mucosa to chronic active gastritis, atrophy, metaplasia and finally gastric adenocarcinoma. This study explores gastric clinical specimens representing different steps of the Correa pathway with the aim of identifying the expression profile of coding- and non-coding RNAs (microRNAs and small RNAs) which may have a role in the Correa's model of gastric carcinogenesis and potentially develop novel clinical biomarkers. We screened for differentially expressed genes in gastric biopsies (antrum/corpus) by employing RNAseq (for microRNAs and non-coding RNAs) and microarrays (for coding RNAs).
Project description:Helicobacter pylori infection can induce gastric pathologies ranging from chronic gastritis to peptic ulcers and gastric cancer. Individuals´ response to H. pylori infection is complex and it depends on a combination of environmental factors, genetic background, host response and strain virulence. The pathway towards gastric cancer is a sequence of events known as the Correa's model of gastric carcinogenesis, a stepwise inflammatory process from normal mucosa to chronic active gastritis, atrophy, metaplasia and finally gastric adenocarcinoma. This study explores gastric clinical specimens representing different steps of the Correa pathway with the aim of identifying the expression profile of coding- and non-coding RNAs (microRNAs and small RNAs) which may have a role in the Correa's model of gastric carcinogenesis and potentially develop novel clinical biomarkers. We screened for differentially expressed genes in gastric biopsies (antrum/corpus) by employing RNAseq (for microRNAs and non-coding RNAs) and microarrays (for coding RNAs).
Project description:Helicobacter pylori infection can induce gastric pathologies ranging from chronic gastritis to peptic ulcers and gastric cancer. Individuals´ response to H. pylori infection is complex and it depends on a combination of environmental factors, genetic background, host response and strain virulence. The pathway towards gastric cancer is a sequence of events known as the Correa's model of gastric carcinogenesis, a stepwise inflammatory process from normal mucosa to chronic active gastritis, atrophy, metaplasia and finally gastric adenocarcinoma. This study explores gastric clinical specimens representing different steps of the Correa pathway with the aim of identifying the expression profile of coding- and non-coding RNAs (microRNAs and small RNAs) which may have a role in the Correa's model of gastric carcinogenesis and potentially develop novel clinical biomarkers. We screened for differentially expressed genes in gastric biopsies (antrum/corpus) by employing RNAseq (for microRNAs and non-coding RNAs) and microarrays (for coding RNAs).
Project description:Carcinogenic bacteria, Helicobacter pylori, induce DNA double-strand breaks in infected host cells. Therefore, we have investigated which genes are upregulated after the infection. Although Helicobacter pylori infection is etiologically related to the inflammation-related malignancy, gastric cancers, it role in the molecular pathogenesis of disease remains unclear. In vitro studies have suggested the infection may cause breaks in double-stranded DNA. We used microarray analysis of H. pylori-infected human gastric biopsies to investigate the effect of H. pylori on gene expression genes involved in DNA repair and DNA damage response. Micro-array analysis and immunohistochemistory showed that ATM (ataxia-telangiectasia mutated) was upregulated in H. pylori gastritis but down regulated in the premalignant lesion, intestinal metaplasia. Studies in gastric cancer cell lines showed that H. pylori-infection induced activation of ATM and formation of ?-H2AX. ?-H2AX formation was present following infection with bout cag pathogenicity island (PAI)- positive and negative strains but more robust with cag PAI positive strains consistent with the fact that both cag PAI positive negative strains are associated with gastric cancer but the risk is higher with cag PAI positive strains. Eradication of H. pylori infection is associated with a reduction in cancer risk even in the most high risk populations. These data provide a plausible molecular mechanism for a direct bacterial-host interaction increasing cancer risk. To identify tumor suppressors affected by H. pylori-infection, microarray screening was used to compare the gene expression profiles of AGS cells, a gastric cancer cell line, infected with various mutants of H. pylori.