The Study of Expression of p53 and Apoptosis in Prostatic Cancer

Kwon, Sung Dae; Cho, Jae Heung

Abstract

PURPOSE: Mutation of the p53 gene in one of the most common genetic abnormalities found in solid human tumors. p53 gene is related to the cell cycle and concerned with the control of cellular proliferation or cell death by mediating ?programmed cell death (Apoptosis)?. The objective of this study is to evauate the expression of p53 mutations and apoptosis with metastatic prostatic adenocarcinoma.
MATERIALS AND METHODS
We examined 31 paraffin-embedded tissues and compared with the tumor grade, survival estimates. Nuclear expression of p53 could be detected using the monoclonal antibody DO-7 and the expression of apoptosis could be detected using Apotag by in situ hybridization method. The study group was divided by Gleason sum score into low score group (score 2-7, 16cases) and high score group (score 8-10, 15cases).
RESULTS
Positive staining for p53 was found in three of sixteen low score group(19%), eight of fifteen high grade group(53%). Diffuse(>20%) staining was considered as positive for p53 expression. Positive expression of p53 showed more frequent in high Gleason score group than low score group(p=0.044). And more expression for p53 was related to more short survival time than negative p53 group(p=0.041). Mean expression for apoptosis in thirty one cases was 32%. In low Gleason score group mean expression for apoptosis was 35% and 28% was found in high Gleason score group. No significant relationship between low and high group in expressing for apoptosis(p=0.2526). No difference was found for survival time between two groups(p=0.96). And no specific relationship was found between the expression of p53 and apoptosis in low and high Gleason score group each other(p=0.275).
CONCLUSIONS
p53 mutations play an important role as aggressive biological properties in the metastatic prostate cancer in relation to Gleason grade. Therefore we might use the extent of p53 expression as an usuful prognostic factor in clinical aspects. But the expression of apoptosis cannot reveal any specific features with tumor grade, survival time.