Heterogeneity of Steroid Binding Sites in Prostatic Carcinoma: Morphological Demonstration and Clinical Implications

Abstract

Prostatic neoplasms were studied for estrogen binding using four methods. Two employed fluorescent estrogen histochemical ligands, one was a new immunocytochemical technique using specific monoclonal antibodies to human estrophilin, and the last procedure was conventional biochemical dextran-coated charcoal assay. Results indicated that the fluorescent ligands recognized closely associated but separate estrogen-binding sites (putative type II sites) which in turn differed from the binding site measured biochemically. Studies with the monoclonal antibodies were nearly always negative, suggesting that prostatic estrogen receptor might vary antigenically from that present in breast and endometrium. Histochemical and biochemical androgen-binding studies were also compared and showed a close association. In the prediction of hormonal response in advanced prostate cancer both showed high sensitivity and low specificity. The addition of estrogen-binding data did not improve the predictive value of the androgen-binding histochemical assay. However, combining results of the biochemical and histochemical androgen-binding assays resulted in significant improvement of the specificity without loss of sensitivity, suggesting that there is a degree of positive interaction between the binding sites assayed by the two methods.

Expression of estrogen receptor in diseased human prostate assessed by non‐radioactive in situ hybridization and immunohistochemistry

“…In biochemical studies, some investigators reported the presence of ER in BPH [9,10] and other groups could not find it [ll-131. In immunohistochemical studies using monoclonal antibody against ER (H222), Wernert et al [34] revealed that stromal and basal cells of BPH were stained extensively positive, but other investigators found no staining in BPH [14,15]. More recently, Schulze and Claus subdivided BPH into non-obstructive and obstructive BPH and found that the stroma of the former had the highest amount of ER, while that of the latter had no ER staining [MI.…”

Histological localization of estrogen receptors in normal and diseased human prostates by immunocytochemistry

“…Additionally, estrogen receptors (ER) have been demonstrated biochemically as well as immunocytochemically [13, 141, again inferring a local physiological role for estrogens in human prostate growth. However, there have been conflicting reports on ER in human prostate, as in some studies estrogen receptors could not be demonstrated in BPH, using biochemical [7, 151 or immunocytochemical methods [9, 16,171.…”

Quantitation of cytosolic and nuclear estrogen and progesterone receptor in benign, untreated, and treated malignant human prostatic tissue by radioligand binding and enzyme‐immunoassays

“…One reason for this is that it has been difficult to demonstrate significant amounts of estrogen receptor (ER) in prostatic tissue: in fact, in most studies in which radioligand binding assays (RBA) were used, little or no cytosolic ER (ERC) has been detected in the majority of BPH specimens [7-1 I]. Cytosolic enzyme-immunoassays [ 10,121 and immunohistochemical studies using monoclonal antibody to ER [ 10,[12][13][14] have also usually failed to detect this receptor, although exceptions have been reported [15].…”