Vascular Endothelial Growth Factor Modulates the Transendothelial Migration of MDA-MB-231 Breast Cancer Cells through Regulation of Brain Microvascular Endothelial Cell Permeability

Vascular endothelial growth factor receptor-2 kinase insert domain receptor (VEGFR2/KDR) is critical for angiogenesis, and VEGFR2 mRNA and protein are expressed in ZR-75 breast cancer cells and induced by 17β-estradiol (E2). Deletion analysis of the VEGFR2 promoter indicates that the proximal GC-rich region is required for both basal and hormone-induced transactivation, and mutation of one or both of the GC-rich motifs at −58 and −44 results in loss of transactivation. Electrophoretic mobility shift and chromatin immunoprecipitation assays show that Sp1, Sp3, and Sp4 proteins bind the GC-rich region of the VEGFR2 promoter. Results of the chromatin immunoprecipitation assay also demonstrate that ERα is constitutively bound to the VEGFR2 promoter and that these interactions are not enhanced after treatment with E2, whereas ERα binding to the region of the pS2 promoter containing an estrogen-responsive element is enhanced by E2. RNA interference studies show that hormone-induced activation of the VEGFR2 promoter constructs requires Sp3 and Sp4 but not Sp1, demonstrating that hormonal activation of VEGFR2 involves a nonclassical mechanism in which ERα/Sp3 and ERα/Sp4 complexes activate GC-rich sites where Sp proteins but not ERα bind DNA. These results show for the first time that Sp3 and Sp4 cooperatively interact with ERα to activate VEGFR2 and are in contrast to previous results showing that several hormone-responsive genes are activated by ERα/Sp1 in breast cancer cell lines.

Download Full-text

Andes Virus Disrupts the Endothelial Cell Barrier by Induction of Vascular Endothelial Growth Factor and Downregulation of VE-Cadherin

Journal of Virology ◽

10.1128/jvi.01405-10 ◽

2010 ◽

Vol 84 (21) ◽

pp. 11227-11234 ◽

Cited By ~ 74

Author(s):

Punya Shrivastava-Ranjan ◽

Pierre E. Rollin ◽

Christina F. Spiropoulou

Keyword(s):

Vascular Endothelial Growth Factor ◽

Endothelial Cells ◽

Endothelial Cell ◽

Growth Factor ◽

Virus Replication ◽

Cell Permeability ◽

Hantavirus Infection ◽

Vascular Endothelial ◽

Andes Virus ◽

Endothelial Growth Factor

ABSTRACT Hantavirus pulmonary syndrome (HPS) and hemorrhagic fever with renal syndrome (HFRS) are severe diseases associated with hantavirus infection. High levels of virus replication occur in microvascular endothelial cells but without a virus-induced cytopathic effect. However, virus infection results in microvascular leakage, which is the hallmark of these diseases. VE-cadherin is a major component of adherens junctions, and its interaction with the vascular endothelial growth factor (VEGF) receptor, VEGF-R2, is important for maintaining the integrity of the endothelial barrier. Here we report that increased secreted VEGF and concomitant decreased VE-cadherin are seen at early times postinfection of human primary lung endothelial cells with an HPS-associated hantavirus, Andes virus. Furthermore, active virus replication results in increased permeability and loss of the integrity of the endothelial cell barrier. VEGF binding to VEGF-R2 is known to result in dissociation of VEGF-R2 from VE-cadherin and in VE-cadherin activation, internalization, and degradation. Consistent with this, we showed that an antibody which blocks VEGF-R2 activation resulted in inhibition of the Andes virus-induced VE-cadherin reduction. These data implicate virus induction of VEGF and reduction in VE-cadherin in the endothelial cell permeability seen in HPS and suggest potential immunotherapeutic targets for the treatment of the disease.

Download Full-text