Abstract: Objective: To investigate the relationship between the expression of Egr-1 protein andheparanase.Methods: The expression of Egr-1and heparanase was examined by SABC（StreptAvidin-Biotin Complex）immunohistochemistry in 58 Paraffin-embedded tissue specimens and 10 control groups of normal bladder tissues.The expression and relationship of Egr-1 and heparanase with clinicopathologic factors and the relationship of Egr-1 and heparanase were analysed . Results: The positive expression rate of Egr-1 in normal bladder tissue was 0%(0/10)，while the positive expression rate of Egr-1 in BTCC was statistically significant(P<0.01).No heparanase expression was detectable in 10 normal bladder tissues，while heparanase expression was detected in 34 of 58 transitional cell carcinoma of bladder(58.62%)。The positive expression of Egr-1 and heparanase in transitional cell carcinoma of bladder had no distinct difference in age，sex，tumorsize and tumor quantity(P>0.05)，but it had a close correlation with the degrees of histological grades and clinical stages（P<0.01). The expression of Egr-1 was closely correlated with that of heparanase (liner index of Pearson=0.3875，P<0.01). Conclusion: the positive experssion of Egr-1 and heparanase might be the referencing indxe of the development and invasion of bladder carcinoma and support a potential involvement of Egr-1 in the progression from non-muscle invasive bladder cancers to muscle invasive bladder cancer. It is shown that Egr-1 may provide theoretical fundation of chemopreventive stategy for bladder cancer in the future.

Key words: bladder transitional cell carcinoma, EGR-1 protein, heparanase, immunohistochemistry