Abstract
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.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Apoptosis / drug effects*
-
Carcinoma, Hepatocellular / metabolism*
-
Carcinoma, Hepatocellular / pathology
-
Cell Cycle Proteins / metabolism
-
Cyclin D1 / metabolism
-
Cyclin-Dependent Kinase Inhibitor p27
-
Down-Regulation
-
Enzyme Inhibitors / pharmacology
-
Fingolimod Hydrochloride
-
G1 Phase / drug effects
-
Glycogen Synthase Kinase 3 / metabolism
-
Glycogen Synthase Kinase 3 beta
-
Humans
-
Immunosuppressive Agents / pharmacology*
-
Liver Neoplasms / metabolism*
-
Liver Neoplasms / pathology
-
Mitogen-Activated Protein Kinase 1 / antagonists & inhibitors
-
Mitogen-Activated Protein Kinase 1 / metabolism
-
Mitogen-Activated Protein Kinase 3 / antagonists & inhibitors
-
Mitogen-Activated Protein Kinase 3 / metabolism
-
Phosphatidylinositol 3-Kinases / metabolism*
-
Phosphorylation / drug effects
-
Propylene Glycols / pharmacology*
-
Protein Serine-Threonine Kinases / metabolism*
-
Proto-Oncogene Proteins / metabolism*
-
Proto-Oncogene Proteins c-akt
-
Sphingosine / analogs & derivatives
-
Tumor Cells, Cultured
-
Tumor Suppressor Protein p53 / metabolism
-
Tumor Suppressor Proteins / metabolism
Substances
-
Cell Cycle Proteins
-
Enzyme Inhibitors
-
Immunosuppressive Agents
-
Propylene Glycols
-
Proto-Oncogene Proteins
-
Tumor Suppressor Protein p53
-
Tumor Suppressor Proteins
-
Cyclin D1
-
Cyclin-Dependent Kinase Inhibitor p27
-
AKT1 protein, human
-
GSK3B protein, human
-
Glycogen Synthase Kinase 3 beta
-
Gsk3b protein, mouse
-
Protein Serine-Threonine Kinases
-
Proto-Oncogene Proteins c-akt
-
Mitogen-Activated Protein Kinase 1
-
Mitogen-Activated Protein Kinase 3
-
Glycogen Synthase Kinase 3
-
Fingolimod Hydrochloride
-
Sphingosine