Helicobacter pylori inhibits activity of cdc2 kinase and delays G2/M to G1 progression in gastric adenocarcinoma cell line.
BACKGROUND
Helicobacter pylori is a bacterial pathogen strongly associated with ulcer diseases and gastric cancer. The bacterial-induced alteration of cell-cycle control in host cells may play a role in the pathogenetic mechanisms. The aims of this study were to define the effect of H. pylori on the G2/M to G1 transition in a gastric cell line.


METHODS
Cultured gastric cells, AGS, were synchronized in the S/early G2 phase and treated with intact H. pylori. The cell-cycle distribution of AGS cells was determined by flow cytometry. The activity of cdc2 kinase, as well as of some parameters that affect the kinase activity, was also examined.


RESULTS
H. pylori delays cell-cycle progression at the G2/M phase in AGS cells. The G2/M delay was associated with reduced activity of cdc2 kinase. Both down-regulation of cell-cycle regulators (p34cdc2, cyclin B1 and cdc25C) and decreased association between p34cdc2 and cyclin B1 were found to be associated with the activity of cdc2 kinase abated after the H. pylori infection. In addition, the H. pylori-induced G2/M delay required direct contact between the bacteria and host cells.


CONCLUSIONS
H. pylori inhibits G2/M to G1 progression and causes a reduction of cell division in gastric epithelial cells.
Chiou
C C
CC
School of Medical Technology, Chang Gung University, Taoyuan, Taiwan.
Chan
C C
CC
Kuo
Y P
YP
Chan
E C
EC
D000230:Adenocarcinoma / Q000378:metabolism / Q000382:microbiology / Q000503:physiopathology*; D015153:Blotting, Western; D016203:CDC2 Protein Kinase / Q000378:metabolism*; D002453:Cell Cycle; D019926:Cyclin B / Q000378:metabolism; D056744:Cyclin B1; D015536:Down-Regulation; D016193:G1 Phase / Q000502:physiology; D016195:G2 Phase / Q000502:physiology; D016480:Helicobacter pylori / Q000502:physiology*; D006801:Humans; D016200:Maturation-Promoting Factor / Q000378:metabolism; D011233:Precipitin Tests; D013274:Stomach Neoplasms / Q000378:metabolism / Q000382:microbiology / Q000503:physiopathology*; D014407:Tumor Cells, Cultured
C534699:CCNB1 protein, human; D019926:Cyclin B; D056744:Cyclin B1; D016203:CDC2 Protein Kinase; D016200:Maturation-Promoting Factor