Melanoma cell-derived vascular endothelial growth factor induces endothelial tubulogenesis within fibrin gels by a metalloproteinase-mediated mechanism

Eur J Cell Biol. 2006 Nov;85(11):1167-77. doi: 10.1016/j.ejcb.2006.07.003. Epub 2006 Sep 1.

Abstract

Angiogenesis is a process required not only for embryonal development but is encountered in wound healing and in pathological situations such as tumour growth. In vitro, formation of capillary-like structures can be induced by seeding human microvascular endothelial cells (HDMECs) on top of a fibrin matrix in the presence of phorbol 12-myristate 13-acetate (PMA) as a stimulating agent. In this study, we show that supernatants collected from high-invasive melanoma cells (BLM) induce the formation of tubular structures similar to PMA treatment whereas supernatants from low-invasive cells (WM164) did not. Analysis of proteins secreted into the supernatant of both melanoma cell lines identified differential expression of several pro-angiogenic proteins in high- and low-invasive melanoma cells. Vascular endothelial growth factor (VEGF) was strongly expressed by high- but not by low-invasive melanoma cells. Neutralisation of VEGF as well as inhibition of matrix metalloproteases (MMPs) using the broad spectrum MMP inhibitor 1,10-phenanthroline, both strongly reduced the melanoma-induced tube formation. PMA treatment of HDMECs on a fibrin matrix stimulated MT1-MMP synthesis, indicating that this protease is involved in PMA-induced angiogenesis. In addition, stimulation of HDMECs by supernatants of BLM melanoma cells resulted in a strong induction of ADAM-15, which is known to act as a metalloproteinase. In conclusion, these results show that VEGF released by melanoma cells is an important mediator of neo-vascularisation and that this process depends on the presence of metalloproteinases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / enzymology
  • Endothelium, Vascular / growth & development*
  • Fibrin / drug effects
  • Fibrin / metabolism
  • Gels
  • Humans
  • Melanoma / metabolism*
  • Melanoma / pathology
  • Metalloendopeptidases / metabolism
  • Metalloproteases / antagonists & inhibitors
  • Metalloproteases / genetics
  • Metalloproteases / metabolism*
  • Neovascularization, Pathologic / metabolism*
  • Phenanthrolines / pharmacology
  • Protease Inhibitors / pharmacology
  • Tetradecanoylphorbol Acetate / pharmacology
  • Tumor Cells, Cultured
  • Vascular Endothelial Growth Factor A / metabolism*

Substances

  • Gels
  • Phenanthrolines
  • Protease Inhibitors
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A
  • Fibrin
  • Metalloproteases
  • Metalloendopeptidases
  • Crotalus adamanteus proteinase II
  • Tetradecanoylphorbol Acetate
  • 1,10-phenanthroline