Androgen receptors in endocrine-therapy-resistant human prostate cancer.
Despite the initial androgen-dependent growth of most human prostate cancers, eventually all prostate cancers become androgen-independent at varying intervals after androgen ablation or anti-androgen therapy. In order to gain more insight into the role of the androgen receptor (AR) in this process, AR and prostate-specific antigen (PA) expression was evaluated immunohistochemically in prostatic tumour tissues from patients who developed urinary flow obstruction between 4 and 107 months after onset of treatment. AR expression was evaluated with a monoclonal antibody (MAb) specific for the N-terminal domain of the human AR. To substantiate the progressive tumour growth, proliferative activity was assessed immunohistochemically by staining with MAb Ki-67. Ki-67-defined tumour-growth fractions varied from 0.8-64.7%. In 13 of the 17 examined tumours over 80% of the tumour cells were AR-positive, 3 tumours showed a considerable heterogeneity in AR expression and in 1 tumour almost all tumour cells seemed to be AR-negative. Two-thirds of the examined tumours contained variable proportions of PA-positive tumour areas. These observations contrast with the view that androgen ablation induces a preferential outgrowth of receptor-negative tumour cells.
van der Kwast
T H
TH
Dept. of Pathology, Erasmus University Rotterdam, The Netherlands.
Schalken
J
J
Ruizeveld de Winter
J A
JA
van Vroonhoven
C C
CC
Mulder
E
E
Boersma
W
W
Trapman
J
J
D000230:Adenocarcinoma / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D000951:Antigens, Neoplasm / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis; D002455:Cell Division; D004351:Drug Resistance; D006728:Hormones / Q000627:therapeutic use*; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000378:metabolism; D017430:Prostate-Specific Antigen; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D011944:Receptors, Androgen / Q000032:analysis*
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D006728:Hormones; D011944:Receptors, Androgen; D017430:Prostate-Specific Antigen