[In vitro cytotoxicity of Helicobacter pylori on hepatocarcinoma HepG2 cells].

BACKGROUND &

OBJECTIVE

Helicobacter pylori (HP) is the important pathogen of chronic gastritis and peptic ulcer. HP infection is closely associated with extragastrointestinal disease of human and animals. This study was designed to investigate the effect of HP on hepatocarcinoma HepG2 cells.

METHODS

HepG2 cells was cocultured with cagA (+) HP and cagA(-) HP at different concentrations. Then the cell morphology, DNA fragments electrophoresis, transmission electron microscopy, MTT method, and enzyme assays were used to observe the effect of HP on the morphology, growth rate, and enzyme change of HepG2 cells.

RESULTS

(1) With the increasing concentrations of cagA (+) HP and prolongation of culture time, the morphology of HepG2 cells was changed from spindle shape to round; the ability of HepG2 cells adhering to wall were decreased; the ability of HepG2 cells in suspension were increased; and debris emitted around the cells; (2) With the increasing concentrations of cagA (+) HP, DNA ladder occurred; (3) With the increasing concentrations of cagA (+) HP and prolongation of culture time, the nuclei of HepG2 cells showed chromatin pyknosis, and clustered on the inner border of karyotheca, condensed cytoplasm with many vacuoles; (4) The MTT values of HepG2 cells were decreased with the increasing concentration of cagA(+) HP (P< 0.01); (5)The values of alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) in coculture supernatants of cagA (+) Hp and HepG2 were increased (P< 0.01); (6) No influence of cagA (-) Hp on HepG2 was found.

CONCLUSIONS

cagA (+) Hp has in vitro cytotoxicity on HepG2 cells, and the cytotoxicity is positively related to the concentration and culture time of cagA(+) HP.