Sp1 recognition sites in the proximal promoter of the human vascular endothelial growth factor gene are essential for platelet-derived growth factor-induced gene expression.
Stimulation of NIH3T3 cells with platelet-derived growth factor (PDGF)-BB enhances expression of vascular endothelial growth factor (VEGF), an endothelial cell-specific mitogen and a key mediator of tumor angiogenesis. Here, we identified cis-acting VEGF promoter elements and trans-acting factors which are involved in PDGF-stimulated VEGF expression. By 5'-deletion and transient transfection analysis, a G + C-rich region at -85 to -50 of the human VEGF promoter was shown to be necessary and sufficient for both PDGF inducible and basal expression. The region contains three potential recognition sites for Sp1 transcription factors, which overlap with two Egr-1 sites. Mutations that abolish the ability of Sp1 to interact with the VEGF promoter element also abrogate expression induced by PDGF. Mutations of the potential Egr-1 binding sites did not affect PDGF responsiveness. Gel shift and antibody supershift analyses showed that Sp1 and Sp3 interact constitutively with the VEGF promoter element. Our data strongly suggest that enhanced VEGF gene expression in PDGF-induced NIH3T3 cells is mediated by Sp1 and/or Sp3 transcription factors bound to the -85 to -50 promoter region of the VEGF gene.
Finkenzeller
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G
Institute of Molecular Medicine, Tumor Biology Center, Freiburg, Germany.
Sparacio
A
A
Technau
A
A
Marmé
D
D
Siemeister
G
G
D016475:3T3 Cells; D000818:Animals; D019138:Antibodies, Blocking / Q000276:immunology; D001482:Base Composition; D002478:Cells, Cultured; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics; D051766:Early Growth Response Protein 1; D016228:Endothelial Growth Factors / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D017874:Immediate-Early Proteins; D008156:Luciferases / Q000235:genetics; D008222:Lymphokines / Q000235:genetics*; D051379:Mice; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D015682:Retroviridae Proteins, Oncogenic / Q000235:genetics; D017384:Sequence Deletion; D016329:Sp1 Transcription Factor / Q000235:genetics* / Q000276:immunology; D016385:TATA Box; D013937:Thymidine Kinase / Q000235:genetics; D015534:Trans-Activators / Q000235:genetics; D014157:Transcription Factors; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D019138:Antibodies, Blocking; D004268:DNA-Binding Proteins; C497325:EGR1 protein, human; D051766:Early Growth Response Protein 1; C486109:Egr1 protein, mouse; D016228:Endothelial Growth Factors; D017874:Immediate-Early Proteins; D008222:Lymphokines; D010982:Platelet-Derived Growth Factor; D015682:Retroviridae Proteins, Oncogenic; D016329:Sp1 Transcription Factor; D015534:Trans-Activators; D014157:Transcription Factors; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D008156:Luciferases; D013937:Thymidine Kinase