Dominative role of MMP-14 over MMP-15 in human urinary bladder carcinoma on the basis of its enhanced specific activity

Human urinary bladder cancer is one of the most common cancers worldwide with the mortality rate of approximately 165,000 people annually. The modulation of extracellular matrix is a crucial event in the metastatic spread, among others in angiogenesis. It is initiated and prolonged by the cascade of matrix metalloproteinases. MMP-14 and MMP-15 are associated with a high degree of malignancy, aggressiveness, and survival prognosis by the activation of other matrix metalloproteinases (MMPs). This study was aimed at evaluating the expression and the activity of selected transmembrane metalloproteinases at different stages of human urinary bladder cancer.

Comparison of investigated enzymes' activity and the inhibitor content suggests it opposite effects, higher suppression of MMP-14 than MMP-15 activity in low-grade bladder cancer and reverse TIMP-1 action in high-grade cancer. The MMP-14 activity determination in urinary bladder cancer tissue may be used as a predictor of a risk of metastasis.

Western blot and enzyme linked immunosorbent assay (ELISA) method were used to evaluate the expression and content of MMPs and TIMP-1. The activity of studied enzymes was determined with fluorometric method.

Both transmembrane metalloproteinases are found in healthy or cancerous tissue in high molecular complexes of human urinary bladder. MMP-14 dominates over MMP-15, particularly in high-grade urinary bladder cancer. Their contents significantly change with the grade of bladder tumor. The amount of MMP-14 increases with increasing grade of tumor. MMP-15 content decreases in high-grade bladder cancer. With increasing grade of urinary bladder cancer their actual activity (per kg of total protein content) is varying in different ways. In all examined tissues, the specific activity of MMP-15 (per kg of the enzyme content) is much higher in comparison to MMP-14. Human urinary bladder cancer contains higher TIMP-1 amounts than control tissue but with the decrease with an increase in tumor grade.