title: Helicobacter pylori CagA and gastric carcinogenesis.
abstract: OBJECTIVE
  This study aimed to demonstrate the tyrosine phosphorylation motif (TPM) and 3' region structure of the Helicobacter pylori CagA gene as well as its SHP-2 binding activity in AGS cells and relation to gastric carcinogenesis.
  
  
  METHODS
  Sixteen clinical isolate H. pylori strains from eight duodenal ulcer and eight gastric adenocarcinoma patients were studied for CagA repeat sequence EPIYA motifs, C-terminal structure, and western blot analysis of CagA protein expression, translocation, and SHP-2 binding in AGS cells.
  
  
  RESULTS
  Except for strain 547, all strains from the gastric adenocarcinoma patients were positive for CagA by PCR and had three EPIYA copy motifs. Western blotting showed that all strains were positive for CagA protein expression (100%), CagA protein translocation (100%), and SHP-2 binding (100%). CagA protein expression was significantly higher in the gastric adenocarcinoma patients than in the duodenal ulcer patients (P=0.0023). CagA protein translocation and SHP-2 binding in the gastric adenocarcinoma patients were higher than those in the duodenal ulcer patients, but no significant differences were found between the two groups (P=0.59, P=0.21, respectively).
  
  
  CONCLUSIONS
  The TPMs and 3' region structures of the H. pylori CagA gene in the duodenal ulcer and gastric adenocarcinoma patients have no significant differences.
authors: Department of Gastroenterology, Yanda International Hospital, East Beijing, China. zhengrinan1964@yahoo.com.cn
authors: Ri-Nan
authors: RN
authors: Zheng
authors: Shu-Rong
authors: SR
authors: Li
authors: Asaka
authors: A
authors: Masahiro
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D000328:Adult; D000942:Antigens, Bacterial / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D063646:Carcinogenesis / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D004381:Duodenal Ulcer / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism; D016481:Helicobacter Infections / Q000150:complications / Q000378:metabolism / Q000382:microbiology; D016480:Helicobacter pylori / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D011485:Protein Binding / Q000235:genetics; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11 / Q000235:genetics / Q000378:metabolism; D013270:Stomach / Q000382:microbiology; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000382:microbiology*
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori; C516724:PTPN11 protein, human; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11