Hormonal regulation of extracellular plasminogen activators and Mr ∼ 54000 plasminogen activator inhibitor in human neoplastic cell lines, studied with monoclonal antibodies

摘要: We have studied the regulation by glucocorticoids and dibutyryl cAMP of amounts urokinase-type plasminogen activator (u-PA), tissue-type (t-PA) a Mr approximately 54000 inhibitor accumulated in serum-free conditioned culture fluid human fibrosarcoma, glioblastoma melanoma cell line (HT-1080, UCT/gl-1 Bowes). For quantitation u-PA t-PA, we used sandwich-type ELISA with combination polyclonal monoclonal antibodies. an estimation variations amount inhibitor, sodium dodecyl sulphate-polyacrylamide gel electrophoresis followed Coomassie blue staining proteins, protein band being identified its selective removal passage fluids through column antibodies against inhibitor. The modulation 3 proteins hormonal agents varied greatly between lines. were independently regulated, sense that did not concomitantly change their levels direction expected either to increase or decrease total extracellular activity. In containing both t-PA two present medium as 120 000 complex. contrast, no complexes found from any lines; this is likely be due occurrence one-chain proenzyme form, which, unlike active u-PA, does react These findings illustrate complexity activity, imply presumed functional diversity may related independent regulation.