Changes of the p57 and bcl-2 mRNA Expression in Human and Rat Prostates after Castration or 5alpha-reductase Inhibitor Administration

Lee, Gyeong Ik; Bahk, Jong Yoon

Abstract

PURPOSE: The voiding difficulty in aged people is usually caused by prostate tumor and these tumors are influenced by the androgen. The purpose of this research was to study the prostatic genetic change caused by changes of hormonal mileu and evaluate the pattern of the changes of p57 and bcl-2 mRNA in human and rat prostate at different biological condition.
MATERIALS AND METHODS
This study was performed in two ways, with animal model and human prostate. As animal model, the rats were castrated surgically or chemically(5-alpha reductase inhibitor) and their prostates were collected according to the schedule. Pattern of expression changes in p57 and bcl-2 mRNA was observed. In human prostate, three normal prostates from young 30th, five benign hyperplastic prostates and five cancerous prostates were collected for evaluation of p57 mRNA expression. The evaluation of the expression of those genes was done by in situ hybridization.
RESULTS
The expression of the p57 mRNA was observed at the cytoplasm in all three types of the prostate tissues. The expressions of mRNA message were increased from the post-orchiectomy three days group up to postorchiectomy two weeks. After two weeks, there were little change in expression of the p57 mRNA. Compared with normal prostate group, the expressions of p57 mRNA were reduced in BPH and prostate cancer groups without treatment. The expression of bcl-2 was increased in expression upto postorchiectomy 4th week and reduced. In BPH and prostate cancer, the expression of the bcl-2 mRNA was increased in comparison with normal prostate.
CONCLUSIONS
With above experiment, the expression patterns of p57 and bcl-2 mRNAs reversed and the prostate cancer showed reduced expression. This result suggests that p57 and bcl-2 may play important roles in differentiation of BPH and prostatic cancer. The differentiation of BPH and prostate cancer by p57 and bcl-2 were impossible.