Original Article
Copyright ©2010 Baishideng. All rights reserved
World J Gastroenterol. Feb 14, 2010; 16(6): 713-722
Published online Feb 14, 2010. doi: 10.3748/wjg.v16.i6.713
Involvement of PI3K and ERK1/2 pathways in hepatocyte growth factor-induced cholangiocarcinoma cell invasion
Apaporn Menakongka, Tuangporn Suthiphongchai
Apaporn Menakongka, Tuangporn Suthiphongchai, Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
Author contributions: Menakongka A performed the experiments, analyzed the data and wrote the manuscript; Suthiphongchai T designed the study, analyzed the data and wrote the manuscript.
Supported by Mahidol University, Thailand and Thailand Research Fund (Suthiphongchai T); Strategic Consortia for Capacity Building of University Faculties and Staff Scholarship, Commission on Higher Education, Ministry of Education, Thailand (Menakongka A)
Correspondence to: Tuangporn Suthiphongchai, Associate Professor, Department of Biochemistry, Faculty of Science, Mahidol University, 272 Rama 6 Road, Bangkok 10400, Thailand. sctsc@mahidol.ac.th
Telephone: +662-2015609 Fax: +662-3547174
Received: October 21, 2009
Revised: November 27, 2009
Accepted: December 4, 2009
Published online: February 14, 2010

AIM: To investigate the role of hepatocyte growth factor (HGF) in cholangiocarcinoma (CCA) cell invasiveness and the mechanisms underlying such cellular responses.

METHODS: Effects of HGF on cell invasion and motility were investigated in two human CCA cell lines, HuCCA-1 and KKU-M213, using Transwell in vitro assay. Levels of proteins of interest and their phosphorylated forms were determined by Western blotting. Localization of E-cadherin was analyzed by immunofluorescence staining and visualized under confocal microscope. Activities of matrix degrading enzymes were determined by zymography.

RESULTS: Both CCA cell lines expressed higher Met levels than the H69 immortalized cholangiocyte cell line. HGF induced invasion and motility of the cell lines and altered E-cadherin from membrane to cytoplasm localization, but did not affect the levels of secreted matrix metalloproteinase (MMP)-2, MMP-9 and urokinase plasminogen activator, key matrix degrading enzymes involved in cell invasion. Concomitantly, HGF stimulated Akt and extracellular signal-regulated kinase (ERK)1/2 phosphorylation but with slightly different kinetic profiles in the two cell lines. Inhibition of the phosphoinositide 3-kinase (PI3K)/Akt pathway by the PI3K inhibitor, LY294002, markedly suppressed HGF-stimulated invasion of both CCA cell lines, and inhibition of the ERK pathway by U0126 suppressed HGF-induced invasion of the KKU-M213 cell line but had a moderate effect on HuCCA-1 cells.

CONCLUSION: These data indicate that HGF promotes CCA cell invasiveness through dys-localization of E-cadherin and induction of cell motility by distinct signaling pathways depending on cell line type.

Keywords: Hepatocyte growth factor, Invasion, Cholangiocarcinoma, Phosphoinositide 3-kinase, Extracellular signal-regulated kinase