Correlation of bcl-2 and p53 Expressions in Urinary Bladder Tumor

Lee, Gilho; Kim, Hyung Jee; Lee, Min Chul

Abstract

PURPOSE: Alteration of p53 tumor suppressor genes is most frequently identified in human neoplasms, including urinary bladder tumor. The overexpression of the bcl-2 gene has been correlated with poor prognosis and chemotherapy resistance in other systems. We evaluated the significance of these gene expressions and correlation with prognostic factors in the urinary bladdder cancer.
MATERIALS AND METHODS
The expression of bcl-2 and p53 oncoprotein were investigated serially in formalin-fixed and paraffin-embedded tissue specimens from 43 patients with primary transitioanl cell carcinoma in the urinary bladder. Thirty four were superficial bladder tumors and nine were invasive tumors. In histology grade according to WHO grading there were 9 grade I, 21 grade II and 13 grade III.
RESULTS
Positive immunoreaction for bcl-2 was found in 3 out of 9 invasive bladder tumors, while 15 of 34 superficial tumors showed positive staining. Positive p53 immunostaining was found in 7 of 9 invasive tumors, while 18 of 34 superficial tumors showed positive staining. There was no significant correlation between bcl-2 or p53 expression and tumor stage(p=0.56, p=0.179). A higher incidence of bcl-2 staining was found in the grade I group than in the grade III group(p=0.041). There was no significant correlation between p53 expression and tumor grade (p=0.23). A significant inverse relationship was found between bcl-2 and p53 topographic expression(p=0.001).
CONCLUSIONS
The results of this study indicated an inverse relationship between bcl-2 and p53 expression. These findings suggest bcl-2 expression may be associated with favorable prognosis in bladder tumor.