Project description:Helicobacter pylori clinical isolates can establish themselves in gastric epithelial stem cells and this interaction may have implications for gastric tumorigenesis. Mouse gastric epithelial progenitor cells (mGEPs) and non-progenitor gastric epithelial cells (npGECs) were infected for 24hrs with Helicobacter pylori clinical isolates Kx1 and Kx2. Kx1 was isolated from a patient with chronic atrophic gastritis (ChAG) and Kx2 from the same patient 4 years later, when he progressed to gastric adenocarcinoma. Keywords: RNA Expression Array
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 clinical isolates can establish themselves in gastric epithelial stem cells and this interaction may have implications for gastric tumorigenesis. Mouse gastric epithelial progenitor cells (mGEPs) were infected for 24hrs with Helicobacter pylori clinical isolates Kx1 and Kx2. Kx1 and Kx2 were also grown in cell media in the absence of cells. Kx1 was isolated from a patient with chronic atrophic gastritis (ChAG) and Kx2 from the same patient 4 years later, when he progressed to gastric adenocarcinoma. Keywords: RNA Expression Array
Project description:In this study, a whole-genome CombiMatrix Custom oligonucleotide tiling microarray with 90000 probes covering six sequenced Helicobacter pylori(H. pylori) genomes was designed and utilized for comparative genomic profiling of eight unsequenced strains isolated from patients with different gastroduodenal diseases in Heilongjiang province of China. Since significant genomic variation were found among these strains, an additional 76 H. pylori stains with different clinical outcomes isolated from various provinces of China were further tested by PCR to demonstrate this distinction. We observed several highly variable regions among strains of gastritis, gastric ulceration and gastric cancer. They are involved in genes associated with bacterial type I, type II and type III R-M system as well as in a virB gene neighboring the well studied cag pathogenic island. Previous studies have reported the diverse genetic characterization of this pathogenic island, but it is conserved in the strains tested by microarray in this study. Moreover, a number of genes involved in the type IV secretion system related to DNA horizontal transfer between H. pylori strains were identified based on the comparative analysis of the strain specific genes. These findings may provide new insights for discovering biomarkers for prediction of gastric diseases.
Project description:Helicobacter pylori (H. pylori) infection and excessive salt intake are known as important risk factors for stomach cancer in humans. However, interactions of these two factors with gene expression profiles during gastric carcinogenesis remain unclear. In this study, we established a mouse gastric tumor model combining a chemical carcinogen, H. pylori infection and a high-salt diet. The tumor incidence and multiplicity in N-methyl-N-nitrosourea-treated mice were significantly increased by combination of H. pylori with a high-salt diet. In addition, detailed examination indicated that excessive salt could regulate progression of gastric tumor. Global gene expression profiles in glandular stomach of the mouse model were investigated by cDNA microarray analysis, and 36 and 31 more than twofold up-regulated and down-regulated genes, respectively, were detected in the H. pylori-infection and high-salt diet combined group compared with the other groups. Quantitative RT-PCR confirmed significant over-expression of several candidate genes including Cd177, Reg3g, and Muc13. These results suggest that our mouse model combined with H. pylori infection and high-salt diet is useful for gene expression profiling in gastric carcinogenesis. Five- to six-week-old male C57BL/6J mice (CLEA Japan, Tokyo, Japan) were inoculated with Helicobacter pylori (Sydney strain 1) (Sample No. 2 and 4) or Brucella broth (Sample No. 1 and 3). The animals were administered 120 ppm N-methyl-N-nitrosourea (MNU) in their drinking water on alternate weeks (total exposure, 5 weeks). Mice were given basal diet (CE-2, CLEA Japan) (Sample No. 1 and 2) or high-salt diet containing 10% NaCl (Sample No. 3 and 4). At 40 weeks, the animals were subjected to deep anesthesia and laparotomy with excision of the stomach.
Project description:Helicobacter pylori clinical isolates can establish themselves in gastric epithelial stem cells and this interaction may have implications for gastric tumorigenesis. Mouse gastric epithelial progenitor cells (mGEPs) and non-progenitor gastric epithelial cells (npGECs) were infected for 24hrs with Helicobacter pylori clinical isolates Kx1 and Kx2. Kx1 was isolated from a patient with chronic atrophic gastritis (ChAG) and Kx2 from the same patient 4 years later, when he progressed to gastric adenocarcinoma. Experiment Overall Design: mGEPs and npGECs were seeded and grown to 70% confluency in RPMI1640 medium supplemented with 10% FBS before being infected with H. pylori strains Kx1 or Kx2 that had been grown to log phase. After 24h, media and non-attached bacteria were washed off and the cells harvested by trypsinization. RNA was prepared from triplicate cultures of mGEP cells infected with Kx1 or Kx2, npGECs infected with Kx1 or Kx2 and uninfected mGEPs and npGECs that served as controls.
Project description:Helicobacter pylori clinical isolates can establish themselves in gastric epithelial stem cells and this interaction may have implications for gastric tumorigenesis. Mouse gastric epithelial progenitor cells (mGEPs) were infected for 24hrs with Helicobacter pylori clinical isolates Kx1 and Kx2. Kx1 and Kx2 were also grown in cell media in the absence of cells. Kx1 was isolated from a patient with chronic atrophic gastritis (ChAG) and Kx2 from the same patient 4 years later, when he progressed to gastric adenocarcinoma. Keywords: RNA Expression Array H. pylori strains Kx1 or Kx2 that had been grown to log phase were used to infect mGEP cells.. After 24h, media and non-attached bacteria were washed off and the cells harvested by trypsinization. RNA was prepared from bacteria infecting mGEP cells or bacterial cultures of Kx1 and Kx2 grown in cell media for 24h in the absence of mGEP cells.
Project description:Forkhead box (Fox) proteins constitute an evolutionarily conserved family of transcriptional regulators whose deregulations lead to tumorigenesis. However, their regulation and function in gastric cancer are unknown. Promoter hypermethylation occurs during Helicobacter pylori (H pylori)-induced gastritis, but whether the deregulated genes contribute to the multi-step gastric carcinogenesis remains unclear. FOXD3 was found to be hypermethylated in a mouse model of H pylori infection and possess tumor-suppressive functions in gastric cancer cell lines. In order to characterize the direct targets of FOXD3 that confer its actions, we performed ChIP-chip in N87 gastric cancer cell line which express low level of FOXD3 in the nuclei of a sub-population of cells. Promoter hypermethylation occurs during Helicobacter pylori (H pylori)-induced gastritis, but whether the deregulated genes contribute to the multi-step gastric carcinogenesis remains unclear. We used MethylCap-microarray to identify hypermethylated genes in a mouse model of H pylori infection.
Project description:Helicobacter pylori are gram-negative bacteria that colonize the human stomach and are the major etiological factor in gastric carcinoma development. The aim of this work was to evaluate changes in gene expression in gastric cells induced by H. pylori.