Abstract
Vascular endothelial growth factor (VEGF) is expressed in multiple hormone-dependent cancer cells/tumors. Treatment of ZR-75 breast cancer cells with 17β-estradiol (E2) induced a greater than fourfold increase of VEGF mRNA levels. ZR-75 breast cancer cells were transfected with pVEGF1, a construct containing a -2018 to +50 VEGF promoter insert, and E2 induced reporter gene (luciferase) activity. Deletion and mutation analysis of the VEGF gene promoter identified a GC-rich region (-66 to -47) which was required for E2-induced transactivation of pVEGF5, a construct containing the minimal promoter (-66 to +54) that exhibited E2-responsiveness. Interactions of nuclear proteins from ZR-75 cells with the proximal GC-rich region of the VEGF gene promoter were investigated by electrophoretic mobility shift and chromatin immunoprecipitation assays. The results demonstrate that both Sp1 and Sp3 proteins bound the GC-rich motif (-66 to -47), and estrogen receptor α (ERα) interactions were confirmed by chromatin immunoprecipitation. Moreover, E2-dependent activation of constructs containing proximal and distal GC/GT-rich regions of the VEGF promoter was inhibited in ZR-75 cells transfected with small inhibitory RNAs for Sp1 and Sp3. These results were consistent with a mechanism of hormone activation of VEGF through ERα/Sp1 and ERα/Sp3 interactions with GC-rich motifs.
Original language | English (US) |
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Pages (from-to) | 1052-1063 |
Number of pages | 12 |
Journal | Oncogene |
Volume | 23 |
Issue number | 5 |
DOIs | |
State | Published - Feb 5 2004 |
Keywords
- ERα/Sp1
- ERα/Sp3
- Estrogen
- Transactivation
- VEGF
ASJC Scopus subject areas
- Molecular Biology
- Genetics
- Cancer Research