FTY720 induces apoptosis of human hepatoma cell lines through PI3-K-mediated Akt dephosphorylation.
Our aim was to study the anticancer effect of the novel immunomodulator FTY720 in vitro and in vivo by investigation of cell cycle entry, cell cycle regulation, cell survival and apoptosis pathways. Three hepatoma cell lines with different p53 statuses (HepG2, Huh-7 and Hep3B) and one non-tumorigenic immortalized liver cell line (MIHA) were used for an in vitro study. The in vivo effects of FTY720 were evaluated in a nude mouse tumor model. Cell cycle distribution and cell cycle regulator proteins p27(Kip1) and cyclin D1, together with the PI3-K/Akt pathway, mitogen-activated protein kinases and cleaved caspase-3 and caspase-9, were evaluated. FTY720 selectively induced cell apoptosis in hepatoma cell lines with overexpression of cleaved caspase-3 and caspase-9, but the same phenomena were not found in MIHA cells. FTY720 induced Akt dephosphorylation at Ser473 mediated by phosphoinositide 3-kinase (PI3-K) inhibition. Dephosphorylation led to down-regulation of p42/p44 and dephosphorylation of Forkhead transcription factor and GSK-3beta and, subsequently, up-regulation of p27(Kip1) and down-regulation of cyclin D1. In our in vivo model FTY720 induced apoptosis of tumor cells by down-regulation of the Akt pathway. FTY720 suppressed tumor growth without notable side-effects in normal liver. In conclusion, FTY720 is a novel anticancer agent that induces apoptosis of hepatoma cell lines both in vitro and in vivo through PI3-K-mediated Akt dephosphorylation in a p53-independent manner.
Centre for the Study of Liver Disease and Department of Surgery, University of Hong Kong, Pokfulam, Hong Kong, China.
Terence K
TK
Lee
Kwan
K
Man
Joanna W
JW
Ho
Chris K
CK
Sun
Kevin T
KT
Ng
Xiang Hong
XH
Wang
Yong Chuan
YC
Wong
Irene O
IO
Ng
Ray
R
Xu
Sheung Tat
ST
Fan
D017209:Apoptosis / Q000187:drug effects*; D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000473:pathology; D018797:Cell Cycle Proteins / Q000378:metabolism; D019938:Cyclin D1 / Q000378:metabolism; D050760:Cyclin-Dependent Kinase Inhibitor p27; D015536:Down-Regulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D000068876:Fingolimod Hydrochloride; D016193:G1 Phase / Q000187:drug effects; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D008113:Liver Neoplasms / Q000378:metabolism* / Q000473:pathology; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D011409:Propylene Glycols / Q000494:pharmacology*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt; D013110:Sphingosine / Q000031:analogs & derivatives; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism
D018797:Cell Cycle Proteins; D019938:Cyclin D1; D050760:Cyclin-Dependent Kinase Inhibitor p27; D004791:Enzyme Inhibitors; D000068876:Fingolimod Hydrochloride; D038362:Glycogen Synthase Kinase 3; D000071679:Glycogen Synthase Kinase 3 beta; D007166:Immunosuppressive Agents; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D019869:Phosphatidylinositol 3-Kinases; D011409:Propylene Glycols; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D013110:Sphingosine; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; C494918:AKT1 protein, human; C000605506:GSK3B protein, human; C000605507:Gsk3b protein, mouse