Inhibition of vascular endothelial growth factor activity by transfection with the soluble FLT-1 gene

J Cardiovasc Pharmacol. 2000 Oct;36(4):498-502. doi: 10.1097/00005344-200010000-00013.


Vascular endothelial growth factor (VEGF)-induced angiogenesis is involved in the etiology of some cardiovascular diseases. The soluble form of VEGF receptor, FLT-1 (sFLT-1), is a potent antagonist of VEGF. Therefore, we investigated whether transfection with the sFLT-1 gene could inhibit VEGF-induced angiogenesis. Human embryonic kidney (HEK)-293 cells were transfected with plasmids containing VEGF and sFLT-1 (pCMV-VEGF and pCMV-sFLT-1) by the calcium-phosphate co-precipitation method. VEGF- and/or sFLT-1-transfected HEK-293 cells were incubated for 24 h, and then conditioned medium was collected. The effects of conditioned medium on angiogenesis were tested by incorporation of [3H]thymidine into human umbilical vein endothelial cells (HUVECs). Expression of VEGF protein was determined by Western blotting. The conditioned medium from sFLT-1 gene-transfected HEK-293 cells significantly inhibited recombinant VEGF-induced increase in [3H]thymidine incorporation by HUVECs. VEGF gene-transfected HEK-293 cells secreted VEGF protein into conditioned medium. This conditioned medium increased [3H]thymidine incorporation by HUVECs, which was significantly inhibited by co-transfection of sFLT-1 gene with VEGF gene. These observations suggested that sFLT-1 gene transfer could inhibit VEGF-induced DNA synthesis of vascular endothelial cells.

MeSH terms

  • Blotting, Western
  • Cell Line
  • Culture Media, Conditioned
  • DNA / biosynthesis
  • DNA / genetics
  • Endothelial Growth Factors / antagonists & inhibitors
  • Endothelial Growth Factors / genetics
  • Endothelial Growth Factors / physiology*
  • Humans
  • Liver / metabolism
  • Lymphokines / antagonists & inhibitors
  • Lymphokines / genetics
  • Lymphokines / physiology*
  • Plasmids / genetics
  • Proto-Oncogene Proteins / genetics*
  • Receptor Protein-Tyrosine Kinases / genetics*
  • Receptors, Growth Factor / genetics*
  • Transfection*
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factor Receptor-1
  • Vascular Endothelial Growth Factors


  • Culture Media, Conditioned
  • Endothelial Growth Factors
  • Lymphokines
  • Proto-Oncogene Proteins
  • Receptors, Growth Factor
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factors
  • DNA
  • Receptor Protein-Tyrosine Kinases
  • Vascular Endothelial Growth Factor Receptor-1