Hypoxia inducible factor-1 is involved in growth factor, glucocorticoid and hypoxia mediated regulation of vascular endothelial growth factor-A in human meningiomas

J Neurooncol. 2014 Sep;119(2):263-73. doi: 10.1007/s11060-014-1503-5. Epub 2014 Jul 1.

Abstract

In meningiomas, neovascularization through angiogenesis is essential for tumor expansion. As the vascular endothelial growth factor-A (VEGF-A) plays an outstanding role in this process, we have studied basal VEGF-A release and some aspects of its regulation in 46 meningiomas and in Ben-Men-1 cells in vitro. Among two putative VEGF-A stimulating growth factors tested, TGF-1β was more potent than TGF-α in enhancing VEGF-A secretion. Hypoxia-mimicking conditions induced by CoCl2 treatment also strongly increased VEGF-A secretion. The synthetic glucocorticoid dexamethasone (DEX) potently suppressed both basal and growth factor or CoCl2-induced VEGF-A release. All these effects were also seen in the Ben-Men-1 cell line in which studies on the role of HIF-1 in the regulation of VEGF-A showed that not only hypoxia but also the growth factors induced HIF-1α and DEX suppressed HIF-1α induction. Therefore, in Ben-Men-1 cells with HIF-1α knock-down the effects of hypoxia, growth factors and DEX on VEGF-A production were strongly impaired. This clearly indicates that HIF-1 not only regulates hypoxia-induced VEGF-A production but also mediates at least in part the effects of growth factors and DEX on VEGF-A synthesis and release. Our findings show the complexity of VEGF-A regulation in meningiomas and point to new options for the pharmacological treatment of these tumors.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antineoplastic Agents, Hormonal / pharmacology
  • Cell Hypoxia / physiology*
  • Cell Line, Tumor
  • Cells, Cultured
  • Cobalt
  • Dexamethasone / pharmacology
  • Dose-Response Relationship, Drug
  • Female
  • Gene Knockdown Techniques
  • Humans
  • Hypoxia-Inducible Factor 1 / genetics
  • Hypoxia-Inducible Factor 1 / metabolism*
  • Male
  • Meningioma / drug therapy
  • Meningioma / metabolism*
  • Middle Aged
  • Transforming Growth Factor alpha / metabolism*
  • Transforming Growth Factor beta / metabolism*
  • Vascular Endothelial Growth Factor A / metabolism*

Substances

  • Antineoplastic Agents, Hormonal
  • Hypoxia-Inducible Factor 1
  • Transforming Growth Factor alpha
  • Transforming Growth Factor beta
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A
  • Cobalt
  • Dexamethasone
  • cobaltous chloride