title: Melanoma cell-derived vascular endothelial growth factor induces endothelial tubulogenesis within fibrin gels by a metalloproteinase-mediated mechanism.
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.
authors.affiliation: Department of Dermatology and Center for Molecular Medicine (CMMC), University of Cologne, Joseph Stelzmann Street 9, D-50931 Cologne, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Löffek
authors.forename: Paola
authors.initials: P
authors.lastname: Zigrino
authors.forename: Julia
authors.initials: J
authors.lastname: Steiger
authors.forename: Peter
authors.initials: P
authors.lastname: Kurschat
authors.forename: Hans
authors.initials: H
authors.lastname: Smola
authors.forename: Cornelia
authors.initials: C
authors.lastname: Mauch
mesh_terms: D004730:Endothelium, Vascular / Q000166:cytology / Q000201:enzymology / Q000254:growth & development*; D005337:Fibrin / Q000187:drug effects / Q000378:metabolism; D005782:Gels; D006801:Humans; D008545:Melanoma / Q000378:metabolism* / Q000473:pathology; D008666:Metalloendopeptidases / Q000378:metabolism; D045726:Metalloproteases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D009389:Neovascularization, Pathologic / Q000378:metabolism*; D010618:Phenanthrolines / Q000494:pharmacology; D011480:Protease Inhibitors / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
chemical_list: D005782:Gels; D010618:Phenanthrolines; D011480:Protease Inhibitors; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D005337:Fibrin; D045726:Metalloproteases; D008666:Metalloendopeptidases; C028220:Crotalus adamanteus proteinase II; D013755:Tetradecanoylphorbol Acetate; C025205:1,10-phenanthroline