Effects of Helicobacter pylori and non-steroidal anti-inflammatory drugs on proliferation of gastric epithelial cells / 中华消化杂志

ABSTRACT

Objective To investigate the interactions and effects of Helicobacter pylori (H.pylori) and non steroidal anti inflammatory drugs (NSAID) on the proliferation of gastric epithelial cells in vitro. Methods After co culturing of gastric cancer cell line AGS cells with H.pylori and/or NSAID (indomethacin and aspirin) for 48 hours, the cell proliferation and proliferating cell nuclear antigen (PCNA) were examined by MTT assay and Western blot. Results cagA positive H.pylori strain NCTC11637, but not cagA negative H.pylori strain NCTC12908, had the effect of enhancing gastric epithelium cell proliferation. However, the effect of proliferation was dependent on the density of H.pylori . It was demonstrated that low density (range from 3.2?10 4 CFU/ml to 4?10 6 CFU/ml) of bacteria suspensions resulted in proliferative effect, while high density (more than 2?10 7 CFU/ml) resulted in inhibition. Besides, indomethacin and aspirin inhibited cell proliferation in a dose dependent manner. Moreover, when AGS cells were incubated with cagA positive H.pylori and NSAID, inhibition rather than proliferation was observed. cagA positive H.pylori strains up regulated the expression of PCNA while indomethacin and aspirin down regulated the level of PCNA expression. Meanwhile, the expression of PCNA was also reduced significantly when AGS was co cultured with H.pylori and NSAID. Conclusions The results indicated that gastric epithelium cell proliferation was associated with different H.pylori strains and its density. cagA positive H.pylori strain is prone to increase cell proliferation, but cagA negative H.pylori strain has no such effect. NSAID can inhibit gastric epithelial cell proliferation and reverse such effect caused by H.pylori.