The inhibition of Ras farnesylation leads to an increase in p27Kip1 and G1 cell cycle arrest.
HR12 is a novel farnesyltransferase inhibitor (FTI). We have shown previously that HR12 induces phenotypic reversion of H-rasV12-transformed Rat1 (Rat1/ras) fibroblasts. This reversion was characterized by formation of cell-cell contacts, focal adhesions and stress fibers. Here we show that HR12 inhibits anchorage independent and dependent growth of Rat1/ras cells. HR12 also suppresses motility and proliferation of Rat1/ras cells, in a wound healing assay. Rat1 fibroblasts transformed with myristoylated H-rasV12 (Rat1/myr-ras) were resistant to HR12. Thus, the effects of HR12 are due to the inhibition of farnesylation of Ras. Cell growth of Rat1/ras cells was arrested at the G1 phase of the cell cycle. Analysis of cell cycle components showed that HR12 treatment of Rat1/ras cells led to elevated cellular levels of the cyclin-dependent kinase inhibitor p27Kip1 and inhibition of the kinase activity of the cyclin E/Cdk2 complex. This is the first time an FTI has been shown to lead to a rise in p27Kip1 levels in ras-transformed cells. The data suggest a new mechanism for FTI action, whereby in ras-transformed cells, the FTI causes an increase in p27Kip1 levels, which in turn inhibit cyclin E/Cdk2 activity, leading to G1 arrest.
Reuveni
Hadas
H
Department of Biological Chemistry, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.
Klein
Shoshana
S
Levitzki
Alexander
A
D000818:Animals; D042846:CDC2-CDC28 Kinases; D002448:Cell Adhesion / Q000502:physiology; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002455:Cell Division / Q000502:physiology; D002460:Cell Line; D019938:Cyclin D1 / Q000378:metabolism; D019927:Cyclin E / Q000378:metabolism; D051357:Cyclin-Dependent Kinase 2; D050759:Cyclin-Dependent Kinase Inhibitor p21; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018844:Cyclin-Dependent Kinases / Q000378:metabolism; D016213:Cyclins / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D016193:G1 Phase / Q000502:physiology*; D006801:Humans; D009842:Oligopeptides / Q000378:metabolism; D010766:Phosphorylation; D017368:Protein Prenylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D051381:Rats; D025521:Tumor Suppressor Proteins / Q000378:metabolism*; D018631:ras Proteins / Q000378:metabolism*
C493956:CDKN1A protein, human; C493958:Cdkn1a protein, rat; C493962:Cdkn1b protein, rat; D018797:Cell Cycle Proteins; D019927:Cyclin E; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D009842:Oligopeptides; D025521:Tumor Suppressor Proteins; C418163:cysteine-N(methyl)valine-N(cyclohexyl)glycine-methionine-O-methyl-ester; D019938:Cyclin D1; D050760:Cyclin-Dependent Kinase Inhibitor p27; D017346:Protein Serine-Threonine Kinases; D042846:CDC2-CDC28 Kinases; C495894:CDK2 protein, human; C495892:Cdk2 protein, rat; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases; D018631:ras Proteins