Modulation of cdk2, cyclin D1, p16INK4a, p21WAF and p27Kip1 expression in endothelial cells by TNF/IFN gamma.
BACKGROUND
Regional administration of high doses of tumor necrosis factor (TNF) and interferon gamma (IFN gamma) to metastatic melanoma patients causes selective disruption of the tumor vasculature. This effect is paralleled by decreased endothelial cell proliferation and suppressed integrin alpha V beta 3-mediated adhesion in vitro. Overexpression of the cyclin-dependent kinase (cdk) inhibitory protein p16INK4a was reported to interfere with integrin alpha V beta 3-dependent melanoma cell adhesion.


METHODS
TNF- and IFN gamma-treated HUVEC were analyzed for cell cycle progression and for protein expression by flow cytometry and Western blotting, respectively. p16INK4a was overexpressed by transient transfection, and HUVEC adhesion was tested in short-term adhesion assays.


RESULTS
TNF and IFN gamma synergistically induced a G1 arrest associated with reduced levels of cyclin D1 and cdk2, and increased expression of the cdk inhibitors p16INK4a, p21WAF and p27Kip1. p16INK4a overexpression, however, had no effect on alpha V beta 3-mediated adhesion.


CONCLUSIONS
These results implicate the down-regulation of cyclin D1 and cdk-2, and up-regulation of p16INK4a, p21WAF and p27Kip1 in the suppression of endothelial cell proliferation induced by TNF/IFN gamma and demonstrate that increased p16INK4a levels are not sufficient to suppress alpha V beta 3-mediated endothelial cell adhesion.
Dormond
Olivier
O
Centre Pluridisciplinaire d'Oncologie (CePO), University of Lausanne Medical School, CH-1011 Lausanne, Switzerland.
Lejeune
Ferdy J
FJ
Ruegg
Curzio
C
D015153:Blotting, Western; D042846:CDC2-CDC28 Kinases; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology; D018797:Cell Cycle Proteins / Q000096:biosynthesis*; D019938:Cyclin D1 / Q000096:biosynthesis; D051357:Cyclin-Dependent Kinase 2; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000096:biosynthesis; D050759:Cyclin-Dependent Kinase Inhibitor p21; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018844:Cyclin-Dependent Kinases / Q000096:biosynthesis; D016213:Cyclins / Q000096:biosynthesis; D004357:Drug Synergism; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D005434:Flow Cytometry; D016193:G1 Phase / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000494:pharmacology; D016160:Retinoblastoma Protein / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D025521:Tumor Suppressor Proteins / Q000096:biosynthesis
C493956:CDKN1A protein, human; D018797:Cell Cycle Proteins; D019941:Cyclin-Dependent Kinase Inhibitor p16; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D011994:Recombinant Proteins; D016160:Retinoblastoma Protein; D014409:Tumor Necrosis Factor-alpha; D025521:Tumor Suppressor Proteins; D019938:Cyclin D1; D050760:Cyclin-Dependent Kinase Inhibitor p27; D007371:Interferon-gamma; D017346:Protein Serine-Threonine Kinases; D042846:CDC2-CDC28 Kinases; C495894:CDK2 protein, human; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases