Estrogen and progesterone receptors in meningiomas: comparison of nuclear binding, dextran-coated charcoal, and immunoperoxidase staining assays

We studied the status of estrogen (ER) and progesterone (PR) receptors in meningiomas removed from 52 patients, comparing dextran-coated charcoal (DCC), nuclear binding (NB), and immunoperoxidase (IP) assays. Each of the assays was performed independently by investigators well-experienced with these assays. The NB assay is a new assay that measures functional steroid receptors--that is, the activation of the receptor and its binding to the nucleus. The assay is very sensitive and requires a relatively small amount of tissue as compared with the DCC assay. In agreement with data from other studies. PR were detected in most meningiomas by all 3 methods: in 69% of the cases by NB, in 76% by DCC, and in 89% by IP. ER were detected in only a few cases: in 33% by NB, in 2% by DCC, and in none by the IP assay. The agreement for PR sites was 62% for all 3 assays; it was 66% between the NB and DCC assays, 67% between the NB and IP assays, and 86% between the DCC and IP assays. Of 26 cases that were positive by the DCC assay, 6 (23%) were negative by NB. The overall agreement for all three ER assays was 65%. The data suggest that the majority of meningiomas contain high-affinity receptors for progesterone, that estrogen receptors are present in only a few meningiomas, and that some of these estrogen and progesterone receptors appear to be functional.     

Estrophilin immunoreactivity versus estrogen receptor binding activity in meningiomas: evidence for multiple estrogen binding sites

The existence of estrogen receptors in human meningiomas has long been a controversial issue. This may be explained, in part, by apparent heterogeneity of estrogen binding sites in meningioma tissue. In this study, estrogen receptors were determined in 58 meningiomas with an enzyme immunoassay using monoclonal antibodies against human estrogen receptor protein (estrophilin) and with a sensitive radioligand binding assay using 125I-labeled estradiol (125I-estradiol) as radioligand. Low levels of estrophilin immunoreactivity were found in tumors from 62% of patients, whereas radioligand binding activity was demonstrated in about 46% of the meningiomas examined. In eight (14%) tissue samples multiple binding sites for estradiol were observed. The immunoreactive binding sites correspond to the classical, high affinity estrogen receptors: the Kd for 125I-estradiol binding to the receptor was approximately 0.2 nM and the binding was specific for estrogens. The second, low affinity class of binding sites considerably influenced measurement of the classical receptor even at low ligand concentrations. The epidemiological and clinical data from patients with meningiomas, and the existence of specific estrogen receptors confirmed by immunochemical detection, may be important factors in a theory of oncogenesis.     

Estrogen receptor immunoreactivity in meningiomas. Comparison with the binding activity of estrogen, progesterone, and androgen receptors

Estrogen receptor (ER) analysis was performed in 70 meningioma samples by means of two assays: an enzyme immunoassay that used monoclonal antibodies against human ER protein (estrophilin), and a sensitive radioligand binding assay that used iodine-125-labeled estradiol as the radioligand. Low levels of ER immunoreactivity were found in tumors from 51% of patients, whereas ER binding activity was demonstrated in 40% of the meningiomas examined. In eight (11%) of the tissue samples, multiple binding sites for estradiol were observed. The immunoreactive binding sites corresponded to those of the classic high-affinity ER. In ligand binding studies, however, measurement of classic ER was considerably influenced by a second low-affinity high-capacity estrogen binding component, even at low ligand concentrations. Binding activity of the progesterone receptor (PR) and androgen receptor (AR) was determined concurrently using 17 alpha-methyl-3H-promegestone (3H-R 5020) and 17 alpha-methyl-3H-trienolone (3H-R 1881), a synthetic gestagen and androgen, respectively. High concentrations of PR were detected in 53 (76%) of the tumors, whereas a moderate number of AR binding sites were demonstrated in 33 (47%) of the tumors. A positive correlation between ER immunoreactivity and AR binding activity is suggestive of estrogen regulation of AR via the ER system. The presence of gonadal steroid receptors in a large proportion of meningiomas and the tendency toward a dependence of receptor concentrations on the histological subtype of the meningioma could have implications for tumor therapy.     

Steroid receptors in human brain and spinal cord tumors

Previous investigators have shown evidence of hormonal receptor protein in human brain tumors. In spite of conflicting results, antiestrogen agents (e.g., tamoxifen) have been used in clinical trials of recurrent unresectable meningiomas. In an effort to accrue further comprehensive in vitro data on this subject, we have evaluated 50 human brain and spinal tumors for estrogen, progesterone, and androgen receptor markers. Twenty-nine of the 50 tumors were meningiomas. The other 21 included 11 gliomas of various grades, 5 schwannomas, 3 metastatic carcinomas, 1 angiofibroma, and 1 craniopharyngioma. Only 8 tumors, all meningiomas, were positive for both progesterone and androgen receptors. The 8th tumor was positive for all three receptor proteins. Our study did not find a significant relationship between meningiomas and the presence of steroid receptor protein. We conclude that the use of antiestrogen agents is not indicated in the treatment of meningioma. No significant relationship to sex, menopausal status, tumor type, or tumor location was observed.     

Hormone receptors in vestibular schwannomas

Summary The possibility that steroid hormones play a role in vestibular schwannoma proliferation has been suggested by a number of investigators. There is conflicting information about the presence of steroid hormone receptors in these tumors. The aim of this study was to examine the expression of androgen, progesterone, glucocorticoid and estrogen receptor messenger ribonucleic acid levels (mRNA) in twenty-one vestibular schwannomas by either Northern blot analysis or the polymerase chain reaction (PCR).Glucocorticoid receptor mRNA was expressed in all twentyone tumors examined. Only two male specimens were positive for androgen receptor mRNA expression by PCR-Southern blot analysis. Thirty-three percent of the schwannomas (7/21) showed a strong band for progesterone receptor mRNA by PCR-Southern blot analysis; there were an equal number of males and females in this group. Estrogen receptor mRNA levels were undetectable in all tumors examined by PCR-Southern blot analysis. These studies suggest that the pattern of steroid receptor expression is different in schwannomas than in meningiomas. Individual vestibular schwannomas need to be examined for their steroid receptor mRNA expression mRNA expression to know whether they will be responsive.     

Estrogen and progesterone receptors in meningiomas

Estradiol and progesterone receptors were studied in 14 patients with meningiomas. Estrogen receptors were detected by specific monoclonal antibodies, whereas progesterone receptors were assayed by the dextran-coated charcoal method. In 9 cases the estrogen receptors were also investigated in cultured tumor cells. Positive estrogen and progesterone receptors were found in 86% of patients. The results have been compared with 11 published series of sex steroid assays in meningiomas. The different rate of positive results in most series can be explained by preoperative glucocorticoid therapy. There is no correlation between the estrogen and progesterone receptor activity, the sex and age of the patients, and the location and histological features of the meningioma. The authors suggest that assays of antiestrogen and antiprogestin drugs in cultured cells can indicate whether this estrogen and progesterone receptor activity may be of therapeutic use.     

Androgen receptor binding activity in meningiomas

Analyses of androgen receptor binding activity in 54 intracranial, intraspinal, and metastatic meningiomas were performed with a specific radioligand binding technique using [3H]R 1881 as radioligand. [3H]R 5020 was used for the concurrent determination of progesterone receptor binding activity. Moderate concentrations of androgen receptors (33.4 +/- 5.4 fmol/mg protein) were detected in 35 (65%), whereas high levels of progesterone binding components (236 +/- 35 fmol/mg protein) were demonstrated in 48 (89%) tumors. The androgen receptor binding activity was positively correlated with the progesterone receptor binding activity (rs = 0.38, p less than 0.05). This relationship is suggestive of an androgen regulation of the progesterone receptor via the androgen receptor system. The presence of androgen and progesterone receptors in a large proportion of meningiomas, and the tendency for a dependence of androgen receptor and progesterone receptor binding activity on the histological subtype could have implications for tumor therapy.     

Estrogen and progestin receptors in acoustic and spinal neurilemmomas. Clinicopathologic correlations

Estradiol and progestin receptors were studied in 20 patients with neuraxial Schwann cell tumors, and their presence was correlated to the clinicopathologic features and the amount of preoperative corticosteroid therapy. Based on an arbitrary cutoff value of 200 fmol per gram of tumor as indicative of a positive receptor value in breast cancer, 4 and 13 of the neurilemmoma tissue samples could be considered as positive for estrogen and progesterone receptors, respectively. Whereas there was no convincing correlation between the estrogen and progestin receptor activity and the age, sex, or menopausal status of the patients, overweight patients had significantly higher estrogen and progestin binding values. The correlation between the amount of preoperative prednisone therapy and the amount of [3H]estradiol and [3H]promegestone binding revealed no dose relationship. Correlating [3H]estradiol and [3H]promegestone content with the histologic type of the schwannomas (Antoni types A and B, respectively), we were not able to draw conclusions, because of the predominance of Antoni type A over Antoni type B tissues in our material. The necessity of nuclear receptor assays, ligand specificity testing, and in vitro studies is stressed as a prerequisite for answering the questions whether neurilemmomas contain genuine sexual steroid hormone receptors and whether these receptors are regulated via an estrogen-estrogen-receptor system as is the case in classical sexual steroid hormone target tissues.     

Sex steroid hormone receptors in normal and dysplastic bone disorders in children

Children with monostotic and polyostotic bone dysplasias often exhibit localized bone overgrowth. We investigated the presence of nuclear estrogen and nuclear progesterone receptors by solid-phase radioimmunoassay, immunocytochemistry, and radioligand binding in osteoblast cell cultures derived from the areas of overgrowth of membranous bone, noninvolved membranous bone, and normal membranous bone from children undergoing elective craniotomy. Membranous bone of normal children had demonstrable levels of nuclear estrogen and progesterone receptors identified by radioimmunoassay and immunocytochemical assay. Two- to threefold increased levels of these receptors (p less than 0.001 versus normals) were found in cultures derived from the involved bone of two children with monostotic fibrous dysplasia and in one patient with polyostotic dysplasia (McCune-Albright syndrome). The noninvolved bone in our patients with fibrous dysplasia exhibited nuclear sex steroid hormone receptor levels similar to those in the normal children. Radioligand binding studies demonstrated increased sex steroid hormone receptors in cultures derived from involved osteoblasts. The presence of an increased level of sex steroid hormone receptor was accompanied by increased alkaline phosphatase activity and increased production of osteocalcin in vitro compared to normal or noninvolved bone. The mechanisms by which sex steroid hormone receptor levels are increased in the ostotic dysplasias remain to be established.     

Comparison of the R-3327H rat prostatic adenocarcinoma to human benign prostatic hyperplasia and metastatic carcinoma of the prostate with regard to steroid hormone receptors

Quantitative analyses of cytosolic steroid hormone receptors were performed on nine tumors from the transplantable rat prostatic adenocarcinoma R-3327H. Androgen receptors and estrogen receptors were found in eight of nine and five of six tumors, respectively. None of the tumours analyzed contained detectable progestin or glucocorticoid receptors (four and seven tumors, respectively). The apparent equilibrium dissociation constants for the androgen and estrogen receptors were 0.7-4.3 nM and 0.6-1.8 nM, respectively. The apparent equilibrium Bmax values (maximum number of binding sites) were 1,500-25,000 fmoles/gm tissue for the androgen receptor and 640 to 5,800 fmoles/gm tissue for the estrogen receptor. A comparison between the receptor contents of the R-3327H rat tumor and human benign prostatic hyperplasia and metastatic carcinoma of the prostate showed that the rat tumor was different from the human tissues in several respects. Hence, the search for an optimal animal model for prostatic carcinoma in man must be continued.     

Progestin and oestrogen receptors in meningiomas. Biochemical characterization,clinical and pathological correlations in 42 cases

Summary Progestin receptors (PR) were evaluated in 40 intracranial and 2 spinal meningiomas. PR measured with radiolabelled R 5020 were found in 93% of cases (³⁹/₄₂). PR levels were significantly higher (p=0.05) in females (mean: 5,720 fmol/gmT) than in males (mean: 3,120 fmol/gmT). Biochemical characterization of the R 5020 saturable binding sites showed that they were mainly cytosolic, had a high affinity constant (Kd 1 nM) and were progestin specific. Correlation with sex suggested some biological activity of PR in meningiomas.Oestrogen receptors (OR) were evaluated in 36 intracranial and 2 spinal meningiomas. OR measured with radiolabelled R 2858 were present in 79% of cases (³⁰/₃₈). OR mean levels were equal in females (mean: 285 fmol/gmT) and in males (mean: 330 fmol/gmT). The relevance of PR and possibly OR in the biology of meningiomas and of leptomeninges was suggested by the presence of receptors in a sample of normal leptomeninges.     

Measurement of nuclear oestrogen receptors in human breast tumours

Recent reports suggest that oestrogen receptors detected in the cytosolic fraction of homogenized human breast tumours might be mainly nuclear receptor released into the cytoplasm during tissue processing. This study thus compares the tumour content of steroid hormone receptors in conventional cytosolic receptor assays with direct measurements of receptor in the cell nucleus. Unoccupied cytoplasmic oestrogen receptors (cER), cytoplasmic progesterone receptors (cPR) and total (occupied plus unoccupied) nuclear oestrogen receptors (nER) have been measured in parallel in human breast tumour tissue using biochemical radioreceptor assay. Of 125 tumours, 62% and 61% were positive for cER and cPR, respectively, 50% contained nER with high affinity for oestradiol (nER I) and 13% expressed nER with low affinity for oestradiol (nER II). The concentration of cER correlated significantly with age, cPR and log nER I. A significant proportion of tumours which were positive for both cytosol receptors also possessed nuclear receptors with high and low affinity for oestrogen. It is possible that this group of tumours which are positive for cER, cPR, nER I and nER II will respond well to hormone therapy.     

Steroid receptor profile in human prostate cancer metastases as compared with primary prostatic carcinoma

The steroid receptor profile in seven prostate cancer metastases was compared with the profile in seven primary prostate cancers. The secondaries were all lymph node metastases, obtained during pelvic lymphadenectomy, preceding radical prostatectomy or irradiation. Cytosol androgen receptor content was higher in metastases, whereas the nuclear androgen receptor content was only one-fourth that in primary cancer. Cytosol progesterone as well as estrogen receptor contents were markedly lower in metastases compared with primary cancer. The steroid receptor profile differed very little between primary cancer and normal tissue. Primary prostatic carcinoma is usually obtained at early stages of the disease, whereas metastases represent a dedifferentiated, more aggressive cell population. This may explain the low amounts of progesterone, estrogen, and nuclear androgen receptor levels. The total androgen receptor content was similar in metastatic and primary disease, however, with a shift towards a cytosolic predominance in metastases. Possibly androgen receptors in metastatic disease are "deactivated."     

Steroid receptors and hormone responsiveness of human prostatic carcinoma

Androgen (AR), estrogen (ER), and progesterone (PR) receptors have been found in human prostatic hyperplasia (BPH) and prostatic carcinoma (PC) (AR mainly in the epithelial compartment and ER in the stromal compartment). These steroid receptors have been studied in the cytosol of 59 prostatic cancers in order to select patients to be treated with endocrine therapy (orchiectomy, administration of antiandrogens). Tissues were collected through transvesical resection and needle biopsy. Tritiated metribolone (R1881), 17b-estradiol and promegestone (R5020) with the use of exchange assay and a dextran-coated charcoal method have been usually employed. In some specimens receptor content was also analyzed in the nuclear fraction. AR was found in the cytosol of 47 of 59 (79.66%), ER in 14 of 26 (53.85%), and PR in 13 of 15 (86.67%) tumors examined. AR was detected in the nuclear fraction of 11 of 26, ER in nine of 13, and PR in two of four tumors examined. AR was found to correlate with the histological grade of the cancers, whereas no correlation could be demonstrated between the histological grade and cytoplasmic or nuclear ER. On the basis of receptor studies, hormonal treatment was started with orchiectomy followed by the administration of cyproterone acetate (CPA) 50 mg twice a day in 26 eligible out of 38 patients available for follow-up with tumors examined for cytoplasmic AR. The response to hormonal therapy depended strictly on the presence of AR. The endocrine treatment used seems, in our opinion, to be the most advisable form of therapy, and is capable of blocking the uptake of androgens of extratesticular origin by prostatic cells. Although the clinical advantages of progestational therapy for human PC are not yet established, the presence of PR in prostatic carcinoma leads us to believe that progestational compounds as well as the progestational activity of CPA may be effective on tumor growth of tissues that are positive for PR.     

PROGESTERONE AND OESTROGEN RECEPTORS IN MENINGIOMAS: BIOCHEMICAL AND CLINICOPATHOLOGICAL CONSIDERATIONS*

Specific progesterone and oestrogen receptor proteins were evaluated by a dextran coated charcoal assay and Scatchard plot analysis in 20 intracranial meningiomas. Eleven tumours (55%) were progesterone receptor (PR) positive (mean 108 fmol/mg cytosol protein), whilst all were oestrogen receptor (ER) negative (ER < 10 fmol/mg cytosol protein). There were no trends to suggest a relationship between epidemiological data (patient age, sex and reproductive status in females) or meningioma location and size and the receptor status of the tumour. However, of the seven meningiomas that were histologically atypical, invasive or clinically recurred within 18 months, six were PR negative (PR < 10 fmol/mg cytosol protein). These results confirm that a large proportion of intracranial meningiomas contain significant amounts of specific PR protein and suggest that PR negative meningiomas are biologically more aggressive than PR positive meningiomas. They are also consistent with the hypotheses that PR proteins are not modulated by oestrogens acting through oestrogen receptors and that there are cytokinetic differences between sex hormone receptor proteins in meningioma and breast carcinoma. The full biochemical, cytological and clinical implication of these preliminary findings will, however, require further evaluation because of the unpredictable long-term behaviour of intracranial meningiomas.     

Progesterone and oestrogen receptors in meningiomas: biochemical and clinicopathological considerations

Specific progesterone and oestrogen receptor proteins were evaluated by a dextran coated charcoal assay and Scatchard plot analysis in 20 intracranial meningiomas. Eleven tumours (55%) were progesterone receptor (PR) positive (mean 108 fmol/mg cytosol protein), whilst all were oestrogen receptor (ER) negative (ER less than 10 fmol/mg cytosol protein). There were no trends to suggest a relationship between epidemiological data (patient age, sex and reproductive status in females) or meningioma location and size and the receptor status of the tumour. However, of the seven meningiomas that were histologically atypical, invasive or clinically recurred within 18 months, six were PR negative (PR less than 10 fmol/mg cytosol protein). These results confirm that a large proportion of intracranial meningiomas contain significant amounts of specific PR protein and suggest that PR negative meningiomas are biologically more aggressive than PR positive meningiomas. They are also consistent with the hypotheses that PR proteins are not modulated by oestrogens acting through oestrogen receptors and that there are cytokinetic differences between sex hormone receptor proteins in meningioma and breast carcinoma. The full biochemical, cytological and clinical implication of these preliminary findings will, however, require further evaluation because of the unpredictable long-term behaviour of intracranial meningiomas.     

Characterization of steroid receptors in human prostate using mibolerone

Accurate quantitation of androgen receptors requires a radioactive ligand which has affinity and specificity for the receptor and which is stable to metabolic enzymes. In this report, we have characterized the properties of 7 alpha,17 alpha-dimethyl-17 beta-hydroxy-4-estren-3-one (mibolerone) in human benign hyperplastic prostate cytosol and compared them to those of 17 beta-hydroxy-17 alpha-methyl-estra-4,9,11-trien-3-one (R1881). Mibolerone was found to have an affinity (Kd = 1.5 nM) greater than R1881. (Kd = 2.3 nM) for the androgen receptor in human prostate tissue. Surprisingly, mibolerone was found to bind with high affinity to the progesterone receptor in both human prostate (Kd = 5.9 nM) and rabbit uterus (Kd = 1.1 nM). However, binding to this receptor in both species could be blocked with a 500-fold excess of triamcinolone acetonide. [3H]Mibolerone binding to the androgen receptor was competed effectively with unlabeled dihydrotestosterone, R1881, and mibolerone but not by progesterone, diethylstilbestrol or R5020, in the presence of triamcinolone acetonide. Interestingly, mibolerone was more resistant to metabolism than R1881 in prostate cytosol when exposed to elevated temperatures (30 degrees C) for extended periods of time. However, when exposed to high-intensity ultraviolet irradiation, both compounds lost 50% of their binding ability in about 30 minutes. Mibolerone was found to have a very low affinity (Ki = 540 nM) for human sex steroid binding protein. These studies demonstrate that mibolerone is a useful ligand for androgen receptor assays. They also emphasize the need for including competitors of progesterone receptor binding in assays utilizing this steroid for androgen receptor measurements.     

Type II estrogen binding sites (EBS) in intracranial tumors

Four meningiomas and six neuroepithelial tumors were assayed for the presence of estrogen receptors (ER), type II estrogen binding sites (EBS) and progesterone receptors (PgR). ER were detected in 7 out of 10 cases with levels ranging between 2.5 and 20.7 fmoles/mg of cytosolic protein. On the contrary, PgR were found in all samples (10 cases) and their levels ranged between 8.8 and 130.6 fmoles/mg of cytosolic protein. All tumor samples expressed appreciable amounts of type II EBS ranging between 452 and 2320 fmoles/mg of protein. Although the precise functional role of type II EBS is still unknown, their presence may reflect an hormonal sensitivity of these tumors.     

Relationship between the content of estrogen and progesterone receptors and the pathological characteristics in human breast cancer

Assays of estrogen receptors (ER) and progesterone receptors (PgR) were performed by using the dextran-coated charcoal (DCC) method in 124 cases of invasive breast cancer. The results were correlated with clinical and pathological characteristics. There was no correlation between steroid hormone receptor contents and menopausal status, size of tumor, axillary lymph node status, or histological type. The presences of ER and PgR were significantly correlated with histological grade and its mitotic component. 78.3% of well-differentiated (Grade I) tumors were ER positive. Of this number, 61.1% were also PgR positive. In contrast, 69.0% of poorly differentiated (Grade III) tumors were ER and PgR negative. Tumors with a prominent lymphoid infiltration demonstrated a low frequency of positive ER and PgR. There was a significant inverse correlation between the degree of lymphoid infiltration and histological grade. These results suggest that the ER and PgR status of tumors may indicate a malignancy, and prognostic information can thus be obtained independently of other known factors such as size of the tumor and axillary lymph node status.     

Relationship between the content of estrogen and progesterone receptors and the pathological characteristics in human breast cancer

Assays of estrogen receptors (ER) and progesterone receptors (PgR) were performed by using the dextran-coated charcoal (DCC) method in 124 cases of invasive breast cancer. The results were correlated with clinical and pathological characteristics. There was no correlation between steroid hormone receptor contents and menopausal status, size of tumor, axillary lymph node status, or histological type. The presences of ER and PgR were significantly correlated with histological grade and its mitotic component. 78.3% of well-differentiated (Grade I) tumors were ER positive. Of this number, 61.1% were also PgR positive. In contrast, 69.0% of poorly differentiated (Grade III) tumors were ER and PgR negative. Tumors with a prominent lymphoid infiltration demonstrated a low frequency of positive ER and PgR. There was a significant inverse correlation between the degree of lymphoid infiltration and histological grade. These results suggest that the ER and PgR status of tumors may indicate a malignancy, and prognostic information can thus be obtained independently of other known factors such as size of the tumor and axillary lymph node status.