Objective:The aim of the study was to investigate the expressions of matrix metalloproteinase-2(MMP-2) and tissue inhibitor of MMP-2(TIMP-2) mRNA in transitional cell carcinomas of bladder and discuss their clinical significances.Methods:Using RT-PCR and real time quantitative PCR(RQ-PCR) technique,the expressions of MMP-2 and TIMP-2 mRNA of 45 cases of bladder carcinoma(tumor group) and 10 cases of normal bladder tissue(control group) were analyzed.Results:MMP-2 and TIMP-2 were not expressed in control group.MMP-2 was expressed in 30 cases tumor samples and TIMP-2 was expressed in 26 cases.The expression of MMP-2 mRNA in non-muscle invasive bladder cancers and grade I cancers was lower than that in muscle invasive bladder cancers and grades II-III cancers respectively.The differences were statistically significant(P<0.05).The expression of MMP-2 in recurrent patients was higher than that in incipient patients.TIMP-2 mRNA expression decreased with grades and stage.The expression of TIMP-2 in non-muscle invasive bladder cancers and grade I cancers was higher than that in muscle invasive bladder cancers and grades II-III cancers respectively.There was statistical difference between two groups(P < 0.05).TIMP-2 expression in incipient patients was higher than that in recurrent patients,but the difference was not significant(P>0.05).Conclusion:These results suggest that MMP-2 and TIMP-2 play an important role in the invasion step of transitional cell carcinoma of bladder.MMP-2 may become a new approach to the diagnosis of bladder carcinoma. Objective: The aim of the study was to investigate the expressions of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of MMP-2 (TIMP-2) mRNA in transitional cell carcinomas of bladder and discuss their clinical significances. Methods: Using RT-PCR and real time quantitative PCR (RQ-PCR) technique, the expressions of MMP-2 and TIMP-2 mRNA of 45 cases of bladder carcinoma (tumor group) and 10 cases of normal bladder tissue (control group) were analyzed. Results: MMP-2 and TIMP-2 were not expressed in control group. MMP-2 was expressed in 30 cases of tumor samples and TIMP-2 was expressed in 26 cases. The expression of MMP-2 mRNA in non-muscle invasive bladder cancers and grade I cancers were lower than that in muscle invasive bladder cancers and grades II-III cancers. These expressions were statistically significant (P <0.05). The expression of MMP-2 in recurrent patients was higher than that in incipient patients. -2 mRNA expression decreased with grades and stage. The expression of TIM P-2 in non-muscle invasive bladder cancers and grade I cancers was higher than that in muscle invasive bladder cancers and grades II-III cancers. Where was statistical difference between two groups (P <0.05). TMP-2 expression in incipient patients was higher than that in recurrent patients, but the difference was not significant (P> 0.05) .Conclusion: These results suggest that MMP-2 and TIMP-2 play an important role in the invasion step of transitional cell carcinoma of bladder. -2 may become a new approach to the diagnosis of bladder carcinoma.