Expression of matrix metalloproteinases in human transitional cell carcinoma of the urinary bladder

Matrix metalloproteinases (MMPs) are associated with invasion and metastasis of several human malignant tumors. Especially so MMP-7, as it is mainly produced by the actual cancer cells. However, the expression of MMP-7 in transitional cell carcinoma (TCC) of the urinary bladder has not been previously investigated. We examined expressions of MMP-7 and MMP-2 in TCC, and compared them with clinicopathological characteristics in TCCs. Tumor samples from 20 patients with TCC of the urinary bladder who had surgery performed at the Osaka City University Medical School Hospital were immunohistochemically stained. Expression of MMP-2 was significantly stronger in advanced stage and high grade tumors than in low stage and low grade tumors. MMP-7 was also expressed in TCC, having a tendency to be more strongly expressed in high than in low grade tumors. However, there was no significant difference of MMP-7 expression between advanced and low stages. This increased expression of MMP-7 in high grade TCC of the urinary bladder may be associated with tumor invasion and metastasis.