[Effect of gastrin on invasiveness of human colon cancer cells].
OBJECTIVE
To investigate the effect of gastrin on invasiveness of human colon cancer cells and the role of gastrin receptor-focal adhesion kinase (FAK) signal transduction pathway in this proess.


METHODS
pCR3.1/GR vector expressing gastrin receptor was transfected into a colorectal cancer cell line Colo320 with lipofectamine 2000, and screened by G418. The expression levels of gastrin receptor of the parental cell line Colo320 and the transfected cell line Colo320/GR were assayed by RT-PCR. On the other hand, antisense oligonucleotide of FAK was used to block its expression. The mock transfected Colo320 and sense oligonucleotide Colo320 cells were used as controls. Colo320 and Colo320/GR cells were treated with increasing doses (0 approximately 100 nmol/L) of gastrin. Invasiveness of Colo320 and Colo320/GR cells was determined by Boyden chamber. Phosphorylation of focal adhesion kinase (FAK) tyr-397 was examined by immunoprecipitation and Western-blot.


RESULTS
RT-PCR results showed that the Colo320/GR cells had an mRNA level four times as high as that of Colo320 cells. Western blot showed that FAK tyr397 phosphorylation of Colo320 cells was apparently decreased. Colo320 and Colo320/GR cells showed a dose-dependent response to gastrin on invasiveness and phosphorylation of FAK tyr-397. Invasiveness of Colo320 cells reached its climax when concentration of gastrin was 100 nmol/L, and FAK tyr-397 phosphorylation was marked when concentration of gastrin was 10 nmol/L, but the latter decreased when gastrin concentration was increased to 100 nmol/L. Colo320/GR cells had the same tendency as Colo320 cells, but showed an even stronger invasiveness and a higher level of FAK tyr-397 phosphorylation than Colo320 cells. Before gastrin stimulation, the invasiveness of Colo320 cells transfected with antisense oligonucleotides and the controls showed no difference. After gastrin stimulation, the increase in invasiveness was much less than that in the controls.


CONCLUSIONS
Gastrin can evidently promote invasiveness of Colo320 cells via gastrin-gastrin receptor-FAK signal transduction pathway.
Ding
Jian
J
Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan 430060, China.
Yu
Jie-ping
JP
Li
Dan
D
Yu
Hong-gang
HG
Luo
He-sheng
HS
Wei
Wen-zhou
WZ
D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000473:pathology*; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000378:metabolism*; D005755:Gastrins / Q000494:pharmacology*; D006801:Humans; D009361:Neoplasm Invasiveness; D015398:Signal Transduction
D005755:Gastrins; D051416:Focal Adhesion Protein-Tyrosine Kinases