The in vitro localization of H 3 estradiol in human prostatic carcinoma. An electron microscopic autoradiographic study

Identification of metastatic cell nucleus in human prostate cancer by electron microscopy

AIM

Metastatic prostate cancer is responsible for a large proportion of deaths worldwide. The aim of this study was to identify metastatic cells and determine if stromal invasion by cancer cells differs from those during metastasis.

METHODS & RESULTS

Tissue biopsy/prostatectomy samples, visualized by transmission electron microscopy, identified that metastatic cells are a lineage of stem cells, which have dedifferentiated into cancerous columnar/cuboidal cells. These cells demonstrate nuclear plasticity; the loss of nuclear membranes and boundary between nucleus and cytoplasm; and the presence of electron dense molecules, which can readily pass through basement membranes and enter the capillary, ready for dissemination to metastatic sites.

CONCLUSION

This is the first study to demonstrate differences between invasive and metastatic cell types.

Androgen, estrogen, and progesterone receptors in normal and aging prostates

Testicular hormones regulate the growth and development of the prostate. The presence of androgen receptors in prostatic tissue and their importance in the normal development of the prostate has been established. Age-related changes in the hormonal milieu, and perhaps steroid hormone receptor profile, could set in motion pathological changes leading to the onset of benign prostatic hyperplasia (BPH) or prostate cancer which primarily affect older men. The accumulation of dihydrotestosterone with age, the reawakening of the inductive potential of the prostatic stroma, the altered rate of apoptosis with age, and the age-related changes in the ratio of testosterone:estrogen have all been implicated in the etiology of BPH. In addition to androgen receptors, several studies have documented the presence of estrogen and progesterone receptors in BPH and prostate cancer. So far, most studies have focussed on the correlation between the presence/absence of steroid hormone receptors and response to hormonal therapy. The molecular mechanisms by which these steroid hormone receptors regulate the onset or progression of BPH and prostate cancer are not yet clear. The chronological changes in the levels and distribution of steroid hormone receptors in normal prostatic tissue and the effect of such changes on the synthesis of growth factors, growth factor receptors, and oncogenes should be investigated.

Effect of stilboestrol and testosterone on the incorporation of 75selenomethionine by prostatic carcinoma cells

Controversy still exists as to whether oestrogens exert a direct effect on the prostatic cell. Incorporation of 75Selenomethionine (SeM) was used as a measure of protein synthesis by prostatic carcinoma cells in vitro to investigate the action of hormones on prostatic carcinoma cells in tissue culture. Stilboestrol (DES) and stilboestrol diphosphate (Honvan) inhibited protein synthesis in a proportion of patients, while testosterone was stimulatory. A similar effect was noted in cells from patients with benign hyperplasia (BPH). This work confirms that oestrogens have a direct inhibitory effect on prostatic cells at high concentrations which can be attained in patients given intravenous stilboestrol diphosphate.

Estrogen and progestin receptors in human prostatic carcinoma

Cytosol receptors for estrogens (ER) and progestins (PR) were assayed in human prostatic carcinoma (CaP) and benign prostatic hyperplasia (BPH). Specimens were obtained from either the peripheral or the periurethral zone of the prostate. Stringent criteria were used to identify and measure 7-8S specific receptor using sucrose gradient analysis in a vertical tube rotor. Progesterone receptor was found in 14 BPH samples assayed and in 12 of 13 prostate cancers. In contrast, the 7-8S estrogen receptor was found in none of the nine benign samples assayed and in all prostate cancers. BPH samples were taken from either peripheral or periurethral zones and gave similar results. The histology of individual specimens did not correlate with either the ER or PR present, and, in the cancers, there was no correlation between the pathologic stage or the Gleason score and receptor content.

Correlation of estrogen and androgen receptor status in prostatic disease measured by high pressure liquid chromatography

To further characterize human prostatic estrogen receptors (ER) determined by high pressure liquid chromatography (HPLC), we checked our procedure by which we nullify estrogen binders (including testosterone binding globulin, TeBG) other than ER by preincubation of cytosols with dihydrotestosterone (DHT). We also showed that the ER exhibited ligand specificity and that ER is present in BPH nuclear extract at 10-fold its concentration in the corresponding cytosols. Of seven prostates with localized cancer determined preoperatively, only 3 showed localization; ER concentration in the cancer parts was lower than in the corresponding surrounding BPH. A total of 22 specimens were evaluated for ER and androgen receptors (AR). Statistically, AR had higher values than ER but there was no correlation between the corresponding AR and ER for each tissue.

Estrogen receptor in human benign prostatic hyperplasia

Estrogens have been proposed as a major etiological factor in the pathogenesis of benign prostatic hyperplasia in man. The presence of estrogen receptor in benign prostatic hyperplasia would support this concept. Using the receptor stabilizer, sodium molybdate, and a hydroxylapatite assay we assayed human benign prostatic hyperplasia for the presence of cytosolic estrogen receptor. For comparison, we assayed estrogen receptor in cytosols of prostatic cancer and normal tissue, and we also measured androgen receptor and progesterone receptor concentrations in the 3 tissue types. Estrogen receptor was present in 8 of 15 benign prostatic hyperplasia specimens at a mean concentration of 9.2 fmol./mg. protein for the estrogen-receptor-positive samples. Sucrose gradient analysis of the estrogen receptor of benign prostatic hyperplasia revealed that it sedimented in the region of 8S, and steroid specificity studies confirmed that the binding to estrogen receptor was estrogen-specific. Estrogen receptor was also found in normal (3 of 3) and malignant (4 of 6) tissues, and all tissues were positive for androgen receptor. The presence of estrogen receptor in human benign prostatic hyperplasia supports the proposal that circulating estrogens may have a role in the pathogenesis of this disorder.

Estrogen receptors and clinical correlations with human prostatic disease

Measurement of estrogen binding in human prostate using high-pressure liquid chromatography (HPLC) revealed the presence of cytosolic estrogen receptors (ER) both in benign prostatic hyperplasia (BPH) and adenocarcinoma. Receptor concentrations correlated with several histopathologic features in the specimens analyzed. Estrogen receptor levels generally were higher in BPH than in cancer specimens although there was a subgroup of patients with poorly differentiated carcinoma with levels higher than those of BPH, HPLC can be used for measuring ER in 50 microliters of cytosol, and thus needle biopsy specimens will be analyzed routinely for ER with this micromethod.

Intraprostatic and subcutaneous transplantation of a spontaneous prostatic carcinoma (11095) to male Fischer rats (F344): an ultrastructural study

A prostate carcinoma arising spontaneously in a Fischer rat was transplanted by cell suspension to male and female Fischer rats. Tumour growth was rapid in both subcutaneous and intraprostatic sites of inoculation in males and subcutaneously in females. The growth rate was greater in male than in female hosts and the tumour developed as a solid form in both groups. It had a heterogeneous cell population with ultrastructural characteristics similar to basal cells of the normal prostate and to tumour cells seen in human prostate adenocarcinoma. Later stages of tumour growth transformed it to a cornifying squamous cell carcinoma. The morphological description of tumours produced by transplantation provides the basis for further studies using this method as a model for investigating the response of prostate carcinoma to endocrine manipulation.

Intracellular flow of particulate steroid-receptor complexes in steroid target cells

The structural expression of nuclear transportation of receptor-bound oestradiol was investigated by immunoelectron microscopy on human breast cancer cells. In oestradiol-treated cells during transportation, oestradiol antibodies attached to cytoplasmic oestradiol-bearing particles which seemed to interact with the nuclear membrane. These particles, subserving the intracellular flow of steroid-receptor complexes, could constitute a special cellular system of macromolecular transport, communication and compartmentalisation.

Adenocarcinoma of prostate: role of 17beta-estradiol and 5alpha-dihydrotestosterone binding proteins

Presence of a specific 17 beta-estradiol-binding protein in prostates of patients with adenocarcinoma without hormonal manipulation prior to surgical resection has been reported by us earlier. The present study involves 40 patients with carcinoma of prostate analyzed during the period December, 1974, through June, 1978. Thirty-four patients had metastatic disease, 26 of these were manipulated hormonally after and 8 prior to receptor protein assay. The other 6 were in clinical Stage C and were subjected to transurethral resection alone. The study confirms our earlier report and outlines the role of 17 beta-estradiol (E2) and possibly 5alpha-dihydrotestosterone (DHT) receptor protein in hormonally responsive and refractory patients. Based on the preliminary findings it seems possible to classify the prostatic carcinoma similar to human mammary cancer for the purpose of selecting patients for endocrine manipulation or treatment with other available modalities.

Subcapsular orchidectomy for carcinoma of the prostate

Our results suggest that subcapsular orchidectomy is at least as effective as oestrogen therapy in producing long-lasting suppression of plasma testosterone. It has many advantages over oestrogen therapy, so that, like Huggins, we believe it to be the hormonal treatment of choice for patients who develop symptoms from carcinoma of the prostate.

Specific binding protein for 17 beta-estradiol in prostate with adenocarcinoma

A specific binding protein for 17beta-estradiol has been detected in prostates of patients with prostatic adenocarcinoma, who had no endocrine manipulation prior to the removal of their prostates. Both the sucrose density gradient centrifugation and dextran-coated charcoal techniques were employed. The 17beta-estradiol binding protein has an approximate sedimentation coefficient of 3.6S and is distinct from cystolic dihydrotestosterone binding protein.

Treatment of advanced carcinoma of the prostate with estramustine phosphate

Estramustine phosphate has been useful in the treatment of advanced carcinoma of the prostate. Objective remissions were obtained with this therapy in 6 of 17 patients (35 per cent). The results presented herein indicate that the clinical response is to a certain extent caused by an estrogen effect, which was clearly demonstrable in a previously untreated patient. A specific cytostatic effect of estramustine phosphate, which is not yet clearly explained, may be responsible for remissions in some patients who have become resistant to conventional hormonal treatment.

Adenocarcinoma of prostate and malignant pericardial effusion

A case of widespread adenocarcinoma of the prostate presenting as a symptomatic pericardial effusion is reported. The administration of high doses of estrogen produced a marked objective response in this patient