Tissue type plasminogen activator, but not urokinase, exerts transformation-enhancing activity.
Previous studies have established that plasma cryoprecipitates of tumor patients, culture media of transformed cells and defined proteolytic fragments of fibronectin enhance the morphological cell transformation ( TEF activity) in cultures of chicken embryo fibroblasts infected with temperature-sensitive mutants of Rous sarcoma virus. We now report that purified human tissue type plasminogen activator (t-PA), but not urokinase (u-PA), has a similar TEF activity, at doses as low as 2 ng/ml (30 pM). Specific antibodies effectively neutralized the activity. No significant contamination (less than or equal to 1%) between the preparations of t-PA and fibronectin (FN) or its fragments ( FNdp ) was detected. The results suggest that t-PA may have a direct role in the process of morphological cell transformation in vitro.
D002471:Cell Transformation, Neoplastic / Q000187:drug effects*; D005353:Fibronectins / Q000032:analysis; D006801:Humans; D010960:Plasminogen Activators / Q000032:analysis / Q000494:pharmacology*; D014568:Urokinase-Type Plasminogen Activator / Q000494:pharmacology*
D005353:Fibronectins; D010960:Plasminogen Activators; D014568:Urokinase-Type Plasminogen Activator