Endostatin causes G1 arrest of endothelial cells through inhibition of cyclin D1.
Endostatin, a type XVIII collagen fragment, is a potent antiangiogenic molecule that inhibits endothelial cell migration, promotes apoptosis, and induces cell cycle arrest in vitro. We have investigated the mechanism by which endostatin causes G(1) arrest in endothelial cells. Endostatin decreased the hyperphosphorylated retinoblastoma gene product and down-regulated cyclin D1 mRNA and protein. Importantly, endostatin was unable to arrest cyclin D1 overexpressing endothelial cells, suggesting that cyclin D1 is a critical target for endostatin action. Next, we analyzed cyclin D1 promoter activity in endothelial cells and found that endostatin down-regulated the cyclin D1 promoter. Using a series of deletion and mutant promoter constructs, we identified the LEF1 site in the cyclin D1 promoter as essential for the inhibitory effect of endostatin. Finally, we showed that endostatin can repress cyclin D1 promoter activity in cells over-expressing beta-catenin but not in cells over-expressing a transcriptional activator that functions through the LEF1 site and is insensitive to beta-catenin. Collectively, our data pointed to a role for cyclin D1, and in particular, transcription through the LEF1 site as critical for endostatin action in vitro and suggest that beta-catenin is a target for endostatin.
Hanai
Jun-ichi
J
Divisions of Nephrology and Hematology-Oncology, Department of Medicine and Center for Study of the Tumor Microenvironment, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA.
Dhanabal
Mohan
M
Karumanchi
S Ananth
SA
Albanese
Chris
C
Waterman
Matthew
M
Chan
Barden
B
Ramchandran
Ramani
R
Pestell
Richard
R
Sukhatme
Vikas P
VP
D020533:Angiogenesis Inhibitors / Q000494:pharmacology*; D001665:Binding Sites; D002453:Cell Cycle; D002478:Cells, Cultured; D003094:Collagen / Q000378:metabolism / Q000494:pharmacology*; D043170:Collagen Type XVIII; D019938:Cyclin D1 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D043169:Endostatins; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D016193:G1 Phase / Q000187:drug effects*; D017353:Gene Deletion; D006801:Humans; D051821:Lymphoid Enhancer-Binding Factor 1; D009154:Mutation; D010446:Peptide Fragments / Q000378:metabolism / Q000494:pharmacology*; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012333:RNA, Messenger / Q000378:metabolism; D016160:Retinoblastoma Protein / Q000378:metabolism; D012190:Retroviridae / Q000378:metabolism; D013997:Time Factors; D015534:Trans-Activators; D014157:Transcription Factors / Q000378:metabolism; D014162:Transfection; D014471:Umbilical Veins / Q000166:cytology; D051176:beta Catenin
D020533:Angiogenesis Inhibitors; C495270:CTNNB1 protein, human; D043170:Collagen Type XVIII; D003598:Cytoskeletal Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D043169:Endostatins; C497573:LEF1 protein, human; D051821:Lymphoid Enhancer-Binding Factor 1; D010446:Peptide Fragments; D012333:RNA, Messenger; D016160:Retinoblastoma Protein; D015534:Trans-Activators; D014157:Transcription Factors; D051176:beta Catenin; D019938:Cyclin D1; D003094:Collagen