title: Tumoral and macrophage uPAR and MMP-9 contribute to the invasiveness of B16 murine melanoma cells.
abstract: The aim of this study was to investigate whether tumor cells as well as tumor-associated macrophages (TAMs) contribute to the generation of protease activities essential to tumor cell invasiveness, such as matrix metalloproteinase 2 and 9 (MMP-2 and MMP-9), and the urokinase-type plasminogen activator (uPA) and uPA receptor (uPAR). We found that the enhanced invasiveness through Matrigel-coated filters of B16 murine melanoma cells stimulated with IFNgamma was associated with an higher expression of uPAR and MMP-9 in these cells. Moreover, treatment with anti-MMP-9 or anti-uPAR monoclonal antibodies abrogated the increase of invasiveness in IFNgamma-stimulated melanoma cells, suggesting a cooperation of uPA system and MMP-9 in cytokine-stimulated invasiveness. Invasiveness through Matrigel was also enhanced in B16 melanoma cells exposed to a medium conditioned by TAMs, represented in our experimental model by thioglycollate-elicited macrophages co-cultivated with melanoma cells. Macrophages isolated from these co-cultures were found to express higher levels of uPAR and MMP-9 compared to macrophage cultures alone, and the pro-invasive activity of the co-culture-conditioned medium was abrogated by anti-MMP-9 monoclonal antibodies, but not anti-uPAR monoclonal antibodies. Furthermore, the enhanced uPAR and MMP-9 expression in macrophages co-cultivated with tumor cells seems a rather specific phenomenon, generated through a cell-to-cell contact mechanism. On the whole, our data point to a cooperation between tumor cells and macrophages elicited by tumor cells themselves in generating key enzymes essential in the promotion of tumor invasiveness, such as uPAR and MMP-9.
authors: Department of Experimental Pathology and Oncology, University of Florence, Florence, Italy.
authors: Chiara
authors: C
authors: Marconi
authors: Francesca
authors: F
authors: Bianchini
authors: Antonella
authors: A
authors: Mannini
authors: Gabriele
authors: G
authors: Mugnai
authors: Salvatore
authors: S
authors: Ruggieri
authors: Lido
authors: L
authors: Calorini
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D015153:Blotting, Western; D002465:Cell Movement; D018920:Coculture Techniques; D003094:Collagen; D017077:Culture Media, Conditioned; D004338:Drug Combinations; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D007371:Interferon-gamma / Q000494:pharmacology; D007797:Laminin; D008264:Macrophages / Q000378:metabolism* / Q000473:pathology; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000276:immunology / Q000378:metabolism*; D061965:Matrix Metalloproteinase Inhibitors; D008546:Melanoma, Experimental / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D009361:Neoplasm Invasiveness; D011509:Proteoglycans; D011956:Receptors, Cell Surface / Q000378:metabolism*; D055293:Receptors, Urokinase Plasminogen Activator; D014407:Tumor Cells, Cultured; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D017077:Culture Media, Conditioned; D004338:Drug Combinations; D007797:Laminin; D061965:Matrix Metalloproteinase Inhibitors; C524899:Plaur protein, mouse; D011509:Proteoglycans; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; C059485:matrigel; D007371:Interferon-gamma; D003094:Collagen; D014568:Urokinase-Type Plasminogen Activator; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9