Glutathione-S-transferase activity in human superficial transitional cell carcinoma of the bladder. Comparison with healthy controls.

Glutathione-S-transferase (GST) activity and glutathione (GSH) content have been studied in human urinary bladder (UB) specimens obtained from healthy controls (HC) (n = 8) and from patients with superficial transitional cell carcinoma (TCC) (n = 9), either in TCC and in adjacent normal (ANE) tissues of the same patient. The GST activity was significantly higher in TCC in comparison with ANE (ten fold) and with HC (five fold). This activity was also significantly higher in HC than in ANE (two fold). The Km values obtained in the whole population (1.26 +/- 0.3 X 10(-3) mol/l) suggest that a unique form of isoenzyme is present in the UB epithelium and that it is the same acidic form "rho" described in erythrocytes. The GSH content was significantly higher in TCC than in ANE (2.5 fold) and also that in HC (three fold). A good correlation between GST activity and GSH content was observed in HC but not in TCC or ANE. These results demonstrate the relation between the activity of the GST system and the development of the TCC as well as its role in the cellular resistance to chemotherapy. A possible decrease of the GST activity before the development of the tumor is also discussed.