[Establishment of Mongolian gerbil model of gastric cancer induced by Helicobacter pylori infection and its proteomics analysis].

OBJECTIVE: To establish an animal model of gastric cancer by long-term infection of Helicobacter pylori (H.pylori) and to elucidate the pathogenesis by proteomics analysis.

METHODS: Fifty male Mongolian gerbils (4-5 week-old and weighted 60-100 g) were infected with H.pylori and the gastric tissues were obtained after the infection at 3, 6, 12 and 24 months. Histological changes were evaluated by H-E staining of the gastric tissue sections. Detection of H.pylori was performed by in-vitro culture of fresh gastric tissue samples, PCR amplification of H.pylori 16s rRNA and localization by silver staining. In addition, proteins extracted from gastric tissue samples were subjected to two-dimensional electrophoresis (2-DE) at various infection time points. Protein spots with increased quantity over the course of H.pylori infection were selected and analyzed by LC-MS/MS. Finally, differentially expressed proteins between human gastric cancer tissue samples and lymph nodes were analyzed by real-time RT-PCR.

RESULTS: Colonization of H.pylori was observed in gastric tissue of gerbils as early as 3 months after H.pylori infection, and persisted till 24 months. Pathological examination of infected animals showed various histological changes including acute gastritis, atrophic gastritis, intestinal metaplasia and gastric carcinoma. Seventy-eight differentially expressed proteins were identified by proteomics analysis, among which 36 proteins were up-regulated and 42 were down-regulated. Analyzed by LC-MS/MS, ten proteins were identified, including lactate dehydrogenase, ATP synthase, fatty acid-binding protein, COX5B, peroxiredoxin-4, peroxide reductase, transgelin, succinyl-CoA ligase, keratin and protein disulfide-isomerase A2, among which transgelin, ATP synthase and lactate dehydrogenase were highly expressed in human gastric carcinoma and lymph nodes.

CONCLUSIONS: H.pylori infection induces the expression of transgelin, ATP synthase and lactate dehydrogenase, implying possible roles in the pathogenesis of gastric diseases including cancer.