Expression And Relationship Between PTEN And MMP-2 In Bladder Transitional Cell Carcinoma

[Objective]To study the expression and relationship between phosphase and tensin homology deleted on chromosome ten(PTEN) and matrix metalloproteinase-2( MMP-2) in bladder transitional cell carcinoma (BTCC) and evaluate their clinical significance to clinicopathology of this tumor invasion .[Methods]The expression of PTEN mRNA and MMP-2 mRNA was examined by RT-PCR analysis in 30 cases of BTCC and 10 cases of normal bladder tissues and its correlations of clinicopathologic features were analyzed. The expression of PTEN and MMP-2 in 52 cases of BTCC and 15 cases of normal bladder tissues was detected by immunohistochemistry test (SP method) and its correlations of clinicopathologic features were analyzed .[Results](1) RT-PCR showed that the expression of PTEN and MMP-2mRNA in the tumors was 0.719±0.092 and 1.021±0.035 respectively(p<0.05),while the expression of PTEN and MMP-2mRNA in normal bladder tissues was 0.632±0.087and 0.315±0.045 respectively(p<0.05) . The higher the grade and the clinical stage of tumor were , the lower the expression of PTEN mRNA was(p<0.05),while the higher the expression of MMP-2mRNA was ( p<0.05 ) .The difference between them exists statistical significance(p<0.05).(2) Immunohistochemistry showed that the positive rate of PTEN and MMP-2 was 44.23%(23/52) and 51.92%(27/52) respectively. With the pathological grade and the clinical stage of tumors being higher ,the lower expression level of PTEN showed(p<0.05),while the expression of MMP-2 increased (p<0.05).In primary cancer and recurrent cancer ,the positive rate of PTEN was 55.56% (20/36 ) and 18.75%(3/16) respectively(p<0.05), The positive rate of MMP-2 was 47.22%(17/36) and 62.5%(10/16) respectively(p>0.05).(3) There was negative correlation between PTEN mRNA and MMP-2 mRNA expression in BTCC((r=-0.465, p<0.01).And PTEN protein and MMP-2 protein expression showed the same results in BTCC.(r=-0.39, p<0.01).[Conclusions]The expression of PTEN and MMP-2 are significantly correlated to the tumor grade and clinical stage, PTEN could down-regulated the MMP-2 at the mRNA level and protein level. Absent expression of PTEN could cause over expression of MMP-2 and make it easy for tumor to penetrate basement membrane and develop infiltration metastasis.