@article{mbs:/content/journal/jgv/10.1099/0022-1317-63-2-365, author = "Mignatti, Paolo and Barlati, Sergio", title = "Enhancement of Plasminogen Activator Activity by the Culture Medium of Rous Sarcoma Virus-transformed Cells", journal= "Journal of General Virology", year = "1982", volume = "63", number = "2", pages = "365-373", doi = "https://doi.org/10.1099/0022-1317-63-2-365", url = "https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-63-2-365", publisher = "Microbiology Society", issn = "1465-2099", type = "Journal Article", keywords = "transformation-enhancing factors", keywords = "Rous sarcoma virus", keywords = "transformed cells", keywords = "plasminogen activator", abstract = "Summary We have tested the effect of the culture medium of chicken embryo fibroblasts (CEF) transformed by Rous sarcoma virus (RSV) on plasminogen activator (PA) activity of normal and RSV-infected cells. The results obtained showed that fibrin digestion by cultures of normal uninfected and RSV-infected cells directly attached to a fibrin substrate was increased when the cells were exposed to the supernatant of an 18 h-culture of CEF transformed by RSV. Addition of cycloheximide to the supernatant completely abolished this effect. Similarly, exposure of both normal and RSV-infected cells to the culture medium of RSV-transformed CEF resulted in a marked increase of the soluble PA activity present in the supernatant. This effect, however, was not abolished by inhibition of protein synthesis. For both the cell-bound and soluble PA activities of normal and RSV-infected cells the stimulatory effect was transient, being maximal between 8 and 12 h of exposure to the transformed cell-conditioned medium and disappearing after 24 h. A possible correlation with transformation-enhancing factor(s), previously reported to be present in the culture medium of transformed cells, is discussed.", }