Protease and Plasminogen Activator Activity in Human Bladder Carcinoma

Summary The ability of human bladder tissue extracts to cleave ¹⁴C‐labelled globin in the absence and in the presence of plasminogen was assayed to quantify non‐specific protease and plasminogen activator (PA) activity, respectively. In normal human bladder tissue the non‐specific protease activity was approximately 2‐fold higher than in tissue samples obtained from transitional cell carcinoma of the bladder (TCC). In contrast, PA activity was almost 4‐fold higher in TCC than in normal transition cell epithelium. Acid‐treated urine from 19 patients with TCC of the bladder exhibited significantly higher levels of plasminogen activator activity than similarly treated urine from controls. These results indicate that malignant transformation of the bladder epithelial tissue results in elevated levels of PA in the tissue and in urine. Further studies are needed to assess the potential of PA determination in the management of bladder cancer patients.