Focal adhesion kinase and Src phosphorylations in HGF-induced proliferation and invasion of human cholangiocarcinoma cell line, HuCCA-1.
OBJECTIVE
To study the role of focal adhesion kinase (FAK) and its association with Src in hepatocyte growth factor (HGF)-induced cell signaling in cholangiocarcinoma progression.


METHODS
Previously isolated HuCCA-1 cells were re-characterized by immunofluorescent staining and reverse transcriptase-polymerase chain reaction assay for the expression of cytokeratin 19, HGF and c-Met mRNA. Cultured HuCCA-1 cells were treated with HGF and determined for cell proliferation and invasion effects by MTT and invasion assays. Western blotting, immunoprecipitation, and co-immunoprecipitation were also performed to study the phosphorylation and interaction of FAK and Src. A novel Src inhibitor (AZM555130) was applied in cultures to investigate the effects on FAK phosphorylation inhibition and on cell proliferation and invasion.


RESULTS
HGF enhanced HuCCA-1 cell proliferation and invasion by mediating FAK and Src phosphorylations. FAK-Src interaction occurred in a time-dependent manner that Src was proved to be an upstream signaling molecule to FAK. The inhibitor to Src decreased FAK phosphorylation level in correlation with the reduction of cell proliferation and invasion.


CONCLUSIONS
FAK plays a significant role in signaling pathway of HGF-responsive cell line derived from cholangiocarcinoma. Autophosphorylated Src, induced by HGF, mediates Src kinase activation, which subsequently phosphorylates its substrate, FAK, and signals to cell proliferation and invasion.
Pongchairerk
Urai
U
Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
Guan
Jun-Lin
JL
Leardkamolkarn
Vijittra
V
D000818:Animals; D002450:Cell Communication; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D018281:Cholangiocarcinoma / Q000378:metabolism* / Q000473:pathology; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000378:metabolism*; D017228:Hepatocyte Growth Factor / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D010766:Phosphorylation; D019061:src-Family Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
D017228:Hepatocyte Growth Factor; D051416:Focal Adhesion Protein-Tyrosine Kinases; D019061:src-Family Kinases