Identification of the glycosaminoglycan keratan sulfate in the prostatic secretory cell.
BACKGROUND
Prostate secretory granules (PSG) represent the basic secretory unit of the prostate gland, containing many of its exocrine proteases. Recent analysis of intraluminal corpora amylacea, a proposed by-product of PSG secretion, detected sulfated glycosaminoglycans (GAG) possibly keratan sulfate (KS), indicating a secretory mechanism for GAG in the human prostate surface epithelial cell.


METHODS
Immunostains using anti-KS and anti-prostate-specific antigen (PSA) were evaluated on 10 sequential radical prostatectomy specimens, three of which had received neoadjuvant antiandrogen therapy. Extracts of normal secretory tissue as well as a sample composed almost entirely of prostatic stroma were subjected to Western blot analysis, using the same antibody panel.


RESULTS
Keratan sulfate secretion from the normal prostate epithelial cell has been confirmed and correlates, as does PSA, with the presence of cytoplasmic PSG. No such correlation exists in most adenocarcinomas or in benign epithelium after androgen ablation. Western blot analyses confirmed tissue immunostains and demonstrated a secretory proteoglycan of 70-95 kDa.


CONCLUSIONS
Recognition of PSG heralds a novel secretory mechanism within the human prostate gland that is linked to the secretion of KS. The role of KS in normal prostate secretion remains unknown, although it appears downregulated in neoplastic and androgen-ablated cells.
Cohen
R J
RJ
Urological Research Centre, Department of Surgery, University of Western Australia, Perth, Western Australia, Australia. ronnie@urc.urc.uwa.edu.au
Holland
J W
JW
Redmond
S L
SL
McNeal
J E
JE
Dawkins
H J
HJ
D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use; D015153:Blotting, Western; D003534:Cyproterone / Q000627:therapeutic use; D003594:Cytoplasmic Granules / Q000737:chemistry / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D007632:Keratan Sulfate / Q000032:analysis / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000737:chemistry / Q000378:metabolism*; D017430:Prostate-Specific Antigen / Q000032:analysis; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000737:chemistry / Q000188:drug therapy / Q000378:metabolism*
D000726:Androgen Antagonists; D007632:Keratan Sulfate; D003534:Cyproterone; D017430:Prostate-Specific Antigen