Clinical Significance of Apoptosis in Transitional Cell Carcinoma of the Bladder and It's Correlation with Expression of Mutnant p53 Protein

Kwon, Dong Deuk; Jung, Hee Jong; Oh, Bong Ryoul; Ryu, Soo Bang; Park, Yang Il

Abstract

PURPOSE: The significance of constitutive apoptosis in the development and progression of transitional ceil carcinoma of the bladder has yet to be investigated. The wild type p53 gene is known to play a significant role in apoptosis. Therefore, mutation of p53 gene, which correlates closely with p53 protein overexpression, would be predicted to limit apoptosis. We evlauated the prognostic significance of apoptosis and the relationship between apoptosis and mutant p53 overexpression in transitional cell carcinoma of bladder.
MATERIALS AND METHODS
The extent of apoptosis was determined by TUNEL(terminal deoxynucleotidyl transferase mediated biotinylated deoxyuridine-triphosphate nick end labeling) stain in 64 paraffin embedded tissue of primacy transitional cell carcinoma specimens. Also, the level of p53 overexpression was determined immunohistochemically on the same tissue.
RESULTS
Although the incidence of apoptosis increased with increasing tumor grade, the difference in indices between grade II and grade III failed to reach statistical significance. The mean apoptotic index(AI) of grade I tumors was significantly lower than that of grade III tumors(p=0.0023). The apoptotic index was not related to p53 overexpression, T(tumor)-category, growth type of tumors and also there was no significant difference in disease-free survival between the bladder tumors with high as opposed to low apoptotic index.
CONCLUSIONS
The results show that AI is related to histological grade in transitional cell bladder tumor, while AI hardly has any independent prognostic significance.