BACKGROUND. Recent identification of eosinophilic prostatic secretory granu
les (PSG) as the major secretory mechanism of the prostate gland and their
loss in neoplasia has prompted scrutiny of their chemical constituents. Pol
yamines, in particular spermine and spermidine (sp/spd) are the major catio
ns found within prostatic secretions, yet their secretory mechanism in norm
al and neoplastic tissues has not been investigated.
METHODS. Normal prostatic tissues and adenocarcinoma from intact and chemic
ally castrated men were preserved in a glutaraldehyde-based fixative (Soluf
ix (R)). Immunostains for sp/spd were performed before and after harsh acid
hydrolysis whereby all protein was removed from tissue sections.
RESULTS. Sp/spd immunoreactivity correlated with PSG as recognized in routi
ne stains in tissues from intact patients before and after acid digestion.
Decrease in sp/spd in untreated carcinomas was directly related to loss of
PSG. After chemical castration, normal glands were mostly devoid of sp/spd
while surviving malignant cells stained positively, despite a significant r
eduction or absence of PSG. Similarly, cancers progressing after castration
were intensely decorated with anti-spermine, despite an almost complete lo
ss of PSG. Cytoplasmic sp/spd staining of these androgen resistant clones w
as in contrast to normal glands no longer acid resistant.
CONCLUSION. The intense eosinophilia of PSG is attributable to polyamines.
Androgen blockade arrests sp/spd production in normal tissue. In contrast,
sp/spd production continues in androgen resistant tumor clones, thereby unc
oupling polyamines from their normal androgen dependent environment. (C) 20
01 Wiley-Liss, Inc.