HEPARANASE PROTEIN AND GENE EXPRESSION IN BLADDER CANCER

Abstract

We determined the association of heparanase protein and messenger (m)RNA expression with bladder cancer invasion and metastasis. The expression of heparanase protein and mRNA was assessed by immunohistochemical staining and in situ hybridization, respectively, in 67 bladder cancer specimens resected at various stages of disease. To our knowledge this is the first systematic study of heparanase protein and mRNA expression in human bladder cancer. The expression of heparanase protein in muscular invasive bladder cancer was significantly higher than in superficial cancer (68% versus 19%, p = 0.0001). It was higher in the primary tumor of patients with lymph node metastatic cancer than those with nonmetastatic cancer (80% versus 37%, p = 0.0006). In high grade disease it was significantly higher than in low grade disease (79% versus 29%, p = 0.0001). The expression of heparanase mRNA was also significantly higher in stage pT3 or greater than in stage pT2 or less bladder cancer (96% versus 33%, p = 0.0003). In metastatic N+ cases it was significantly higher than in nonmetastatic bladder cancer (93% versus 46%, p = 0.0037). The heparanase gene and protein showed similar patterns of expression in bladder cancer. Our study implies that the expression of heparanase protein and mRNA is associated with bladder cancer invasion and metastasis, and heparanase may have a role in disease progression.