IMMUNOHISTOCHEMICAL QUANTIFICATION AND DETERMINATION OF CATHEPSIN-D IN PROSTATIC NEOPLASIA - CORRELATION WITH STEROID-RECEPTORS

The role of cathepsin D and androgen (AR), estrogen (ER), and propeste rone receptor (PR) status in prostate tumor growth and invasion was in vestigated using immunohistochemistry in 60 paraffin-embedded sections from radical prostatectomy specimens. Results were assessed by semiqu antitative image analysis in prostate cancers, benign prostatic hyperp lasia (BPH), and areas of prostatic intraepithelial neoplasia (PIN) ad jacent to tumor. Of the 60 prostatic sections, 73% expressed cathepsin D,90% AR, 30% ER, and 18.3% PR. Antibodies exhibited heterogeneous im munostaining and distribution patterns. In epithelial cells, cathepsin D immunoreactivity was predominantly cytoplasmic; that of AR, ER, and PR was mainly nuclear. In PIN tissue, cathepsin D and steroid recepto rs concentrated in the basal layer, in BPH in the secretory luminal ce lls. Cathepsin D, AR, and ER histologic scores progressively increased from BPH to PIN to prostate cancer, whereas PR histologic scores were higher in BPH than in prostate cancer or PIN. AR, ER, and PR histolog ic scores did not correlate significantly with the histologic grade of malignancy, whereas cathepsin D protein levels were significantly hig her in Gleason score sum 7 tumors than in Gleason score sum 5 and 6. S pearman rank's analysis showed that cathepsin D correlated significant ly with ER and PR H-scores, but not with AR. Densitometric analysis of immunostained antigens is a valid method for assessing cathepsin D an d steroid receptor status in prostate tumors. The heterogeneity of cat hepsin D and steroid receptor expression reflects the heterogeneity of prostatic tissue. The expression of cathepsin D could be modulated by estrogens in the prostate, as suggested by the positive correlation b etween cathepsin D and ER. Cathepsin D may intervene in the progressio n of prostate cancer and acts independently of AR.