SIGNIFICANCE OF MATRIX METALLOPROTEINASES AND TISSUE INHIBITORS OF METALLOPROTEINASE EXPRESSION IN THE RECURRENCE OF SUPERFICIAL TRANSITIONAL CELL CARCINOMA OF THE BLADDER

We determined whether expression levels of matrix metalloproteinase (MMP)-2, MMP-9, membrane-type MMP-1 (MT1-MMP), tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 messenger (m) RNA in superficial transitional cell carcinoma of the bladder may be used as predictors of tumor recurrence.Total RNA was extracted from 51 superficial transitional cell carcinomas of the bladder, and expression levels of MMP-2, MMP-9, MT1-MMP, TIMP-1 and TIMP-2 messenger mRNA in these specimens were measured by Northern blot analysis. Results were evaluated in regard to tumor recurrence.Mean MMP-9 and TIMP-2 mRNA expression in the tumors of patients with recurrence were 2.5 and 3-fold higher, respectively, than in those of patients without recurrence despite no significant differences in MMP-2, MT1-MMP or TIMP-1 expression. The recurrence-free survival rate of patients with elevated MMP-9 and TIMP-2 mRNA expression was significantly lower than that of patients with normal MMP-9 and TIMP-2 expression, respectively. In addition, Cox's multivariate analysis revealed that elevated MMP-9 and TIMP-2 were strongly associated with a high incidence of intravesical recurrence of superficial bladder cancer.These results indicate that MMP-9 and TIMP-2 are strongly expressed in the tumors of patients with recurrence compared with those without recurrence and elevated MMP-9 and TIMP-2 may be used as predictors of recurrence in patients with superficial transitional cell carcinoma.