3A Study of the Significance of Apoptosis and its Association with Abnormalities in Expression of BCL-2 Proto-Oncogene in Benign Nodular Hyperplasia of Prostate

摘要

Benign Prostatic Hyperplasia (BPH) is an enlargement of the prostate gland caused by an increase in the number of glandular units. Apoptosis is a programmed cell death necessary for the regulation of the size of organs in adult life. Disruption of apoptotic pathways has been suggested as an important regulatory mechanism in BPH. A high level of the BCL-2 protein suppresses apoptosis by preventing the activation of the enzymes that carry out the process. In this study, an attempt was made to observe the abnormal expression of BCL-2 protein in BPH tissues in paraffin sections and to demonstrate the disruption of apoptotic pathways in BPH. Prostatic tissue from 30 patients with BPH and no prior prostatic carcinoma were obtained by transurethral resection of prostate procedure. Apoptotic index was compared in the H and E sections. Expression of BCL-2 was analyzed by immunohistochemistry and evaluated. Apoptotic index in BPH tissues was found to be twice lower than that of normal tissues. Wilcoxon signed rank test was employed and the p-value proved that the results were highly significant (p<0.01). This data supported the research hypothesis that apoptotic index is decreased in benign prostatic hyperplasia. Out of 30 tissue samples, 20 (67%) shown positivity for BCL-2 expression. Kendall’s Tau-B test was applied and the result showed negative correlation between the intensity of BCL-2 expression and apoptosis, however not significantly. This proves, the theory that BCL-2 regulates individual cell death up to a certain extent.