Active transforming growth factor-β in human melanoma cell lines: No evidence for plasmin-related activation of latent TGF-β

✍ Scribed by Jozef Bizik; Diana Felnerova; Marta Grofova; Antti Vaheri

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 929 KB
• Volume: 62
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/(sici)1097-4644(199607)62:1<113::aid-jcb12>3.0.co;2-o

✦ Synopsis

Cultured human melanoma cells were found to secrete TGF-P mostly in latent biologically inactive form but in addition five of six melanoma cell lines studied produced in conditioned culture medium active TGF-p in the range from 370 to 61 0 pg per 1 O6 cells per 24 h. A distinct characteristic of these melanoma cell lines is that they form active surface-bound plasmin by the activation of plasminogen with surface-bound tissue-type plasminogen activator. The present study was performed to assess the role of plasmin in the process of latent TGF-P activation in the melanoma cell lines. No direct correlation was found between cell-associated plasmin activity and the amount of active TGF-P present in the conditioned medium of individual cell lines. The melanoma cell lines exhibited diverse responses to exogenous active TGF-PI; three cell lines were growth-stimulated, two were growth-inhibited, and one had a very low sensitivity to the growth factor. The active TGF-P produced by the melanoma cells was found to inhibit the natural killer cell function of peripheral blood lymphocytes, suggesting that it may have an immunosuppressive effect and a role in the development of melanomas. o 1996 Wiley-Liss, Inc.