ABSTRACT
The prostatic glandular cells are largely composed of secretory cells and basal cells. Secretory cells produce various enzymatic substance including prostatic specific antigen (PSA), while basal cells have been known to play an important role in the proliferation of the glandular cells. We evaluated the proliferative potential of secretory cells and basal cells in benign prostatic hyperplasia (BPH) and prostate cancer (CAP) by immunohistochemistry. The prostate tissue obtained from 19 patients with BPH and 19 patients with CaP was used in this study. Double staining with PSA and a basal cell marker, cytokeratin (34betaE12) was performed to evaluate the distribution of each cell type in BPH and CaP. Double staining with proliferating cell nuclear antigen (PCNA) and 34betaE12 was carried out to determine the proliferative potential of each cell type. Partial or total loss of basal cell layer was identified in CaP in contrast to intact basal cell layer in BPH. Proportion of basal cells and secretory cells in PCNA positive cells in BPH were 84.6+/-2.0% and 15.4+/-2.0%. In contrast, proportion of basal cells and secretory cells in PCNA positive cells were 1.1+/-1.5% and 98.9+/-1.5% in CaP. PCNA index (PCNA positive cells in 1,000 cells) in CaP was well correlated with Gleason score, but not with pathologic stage. Interestingly, PCNA index in basal cell was significantly higher in stromal type BPH (including fibrous, fibromuscular and muscular type) than that in glandular type BPH (including fibroadenomatous and fibromyoadenomatous type). Taken together, the basal cell play a major role in the proliferation of glandular cells of BPH, while loss of basal cell layer and overproliferation of secretory cells in CaP might lead cancer cells to invade into the stroma. Since higher basal cell PCNA index was noted in glandular type BPH, it is probable that the proliferative potential of basal cell induce secretory cell proliferation.