Cathepsins B, H, and L activities in urine of patients with transitional cell carcinoma of the bladder.

Objectives: Cathepsin B, H, and L (CB, CH, CL) are lysosomal proteolytic enzymes that belong to the group of cysteine proteinases. The imbalance between proteinases and their inhibitors is believed to correlate with tumor progression and shortened patient survival. In transitional cell carcinoma (TCC) only limited data have been published.

Methods: Using spectrofluorometric assays, catalytic activities of CB, CH, and CL in urine were measured to evaluate the potential diagnostic and prognostic value for patients with TCC of the bladder. Second morning urine was collected and used for measurements. CB, CH, and CL activities were determined for groups of patients with superficial disease (Ta-1, n = 43) and muscle-invasive tumors (T2, n = 18; or greater than T2, n = 9), as well as for different tumor grades (G1, n = 12; G2, n = 26; and G3, n = 31). For comparison, 14 urine samples from patients with bladder inflammation and 43 samples from a control group were also included.

Results: Compared with the control group, patients with superficial Stage Ta-T1 disease and muscle-invasive Stage T2 or greater disease, as well as patients with G3 tumors, revealed significantly higher urinary CL activity. CB and CH did not show any tumor-related activity increase. CB was significantly lower in patients with nonrecurrent tumors.

Conclusions: These results suggest that elevated levels of CL in urine might be indicative of a cellular proteolytic imbalance in TCC of the bladder and may have a prognostic and/or diagnostic value.