Histochemical analyses of steroid hormone receptors in breast and prostatic carcinoma

Bmi-1, c-myc, and Snail expression in primary breast cancers and their metastases--elevated Bmi-1 expression in late breast cancer relapses

Breast cancer is known for its propensity to recur decades after treatment. The biology behind the phenomenon of tumor dormancy is still poorly understood. Bmi-1, c-myc, and Snail are transcription factors that have prognostic roles in several malignancies. In order to reveal whether any of these markers has impact on late relapses, we used immunohistochemistry to study the expression of Bmi-1, c-myc, Snail, and estrogen receptor in 73 primary breast cancers and in their metastatic relapses detected within 2 years, or 5 or 10 years after primary surgery. The expression of Bmi-1 was higher in the metastases than in their corresponding primary tumors in both early and late relapses. The highest expression of Bmi-1 was seen in the very late relapsing tumors (first tumor relapse after 10 years). Previously, Bmi-1 has been reported to function as a marker of tumor stem cells in breast cancer. Our results indicate that metastases, when compared to primary tumors, arise from tumor cells that have retained stem cell properties. We also analyzed the relationship between the expression of these markers and clinical parameters. A significant association between the expression of Bmi-1 and estrogen receptor was found. Nuclear expression of c-myc in primary tumors correlated with an increased risk for axillary lymph node metastasis.

Prognostic relevance of androgen receptor detection in operable breast cancer

BACKGROUND AND OBJECTIVES

Androgen receptor (AR) is relevant for prognostication in breast cancer. Different determination methods and cut-off levels hamper interpretation and comparisons of studies. Long-term prognostic evaluation of different AR assays in patients comprising operable breast cancers is scarce.

METHODS

AR was evaluated in 120 primary tumors using the dextran-coated charcoal method (charc-AR), and quantitative immunohistochemistry (IHC) on whole sections (WS) and tissue microarrays (TMA). Nuclear and cytoplasmic-AR localization was determined, and the prognostic importance of AR assays was assessed. Comparisons and correlations with the mitotic activity index (MAI), estrogen receptor (ERalpha), progesterone receptor (PR), HER-2, and histological grade (WHO I-III) were made.

RESULTS

Nuclear-AR in WS, but not charc-AR, strongly correlated with MAI (P = 0.001). However, prognostic information appeared in univariate survival analyses only. Nuclear-AR in TMA was not prognostic. Charc-AR was independent prognostic in node positives both for relapse free survival (RFS) and breast cancer specific survival (BCSS). Both charc-AR and IHC cytoplasmic-AR provided independent prognostic survival information for BCSS in women <55 years.

CONCLUSION

Methods that can detect AR localized in the cytoplasm yield important prognostic information, and further studies in patients with operable breast cancer are warranted.

Vesicles in the subacrosomal space and partial diaphragms in the subacrosomal nuclear envelope of round spermatids of a rat injected intravenously with gold labeled-testosterone-bovine serum albumin conjugate: vesicular trafficking from acrosome to nucleus

Colloidal gold labeled-testosterone-bovine serum albumin conjugate (testosterone-BSA-gold) injected into the vascular system of rats is taken up by endocytosis into round spermatids. Based on observation of silver deposits indicating testosterone-BSA-gold with silver enhancement, we have suggested that testosterone-BSA-gold enters the nuclei through not only the postacrosomal nuclear envelope but also the subacrosomal nuclear envelope (SNE) via the acrosome (Nishimura and Nakano, 1997). However, it was unclear how testosterone-BSA-gold in the acrosome entered the nucleoplasm. Spermatids showing silver deposits on the subacrosomal space were observed under electron microscope without silver enhancement, to clarify the courses of translocation. In the spermatids, vesicles with the gold particles were seen in the subacrosomal space. Some of the vesicles were in contact with the SNE. A part of the outer nuclear membrane projected into the space. Furthermore, local single-bilayer nuclear membranes, which seemed to partially lack nuclear lamina, were present in the SNE. These results indicate the possibility that the vesicles mediate the transport of testosterone-BSA-gold from acrosome to nucleus, and that the vesicle membrane fuses with not only the outer nuclear membrane but also a shared bilayer in the SNE.

Immunocytochemical localization of bovine serum albumin (BSA) in the liver and testis of rats injected with testosterone-BSA, hydrocortisone-BSA or corticosterone-BSA

Through observations of colloidal gold with silver enhancement, we have demonstrated that 2-nm colloidal gold labeled-testosterone-bovine serum albumin (BSA) conjugate or hydrocortisone-BSA conjugate injected intravenously enters the hormone-target cell nuclei of rats (Nishimura and Ichihara, 1997; Nishimura and Nakano, 1997, 1999). To confirm immunocytochemically whether the nature of BSA in the steroid hormone-BSA conjugates (steroid-BSAs) remains intact in the hormone-target cell nuclei, testosterone-BSA, hydrocortisone-BSA or corticosterone-BSA was injected into the vascular system of rats, then the liver and testes of rats killed 2 h postinjection were reacted with FITC-conjugated anti-BSA antibody, and examined under fluorescence microscopy and confocal laser scanning microscopy. In the liver of rat injected with testosterone-BSA, the fluorescence was observed in the nuclei of endothelial cells, but not in the nuclei of hepatocytes, hepatic stellate cells and Kupffer cells. In the liver of rat injected with hydrocortisone-BSA, intense fluorescence was seen in the nuclei of hepatic stellate cells, but did not seem to be present in the nuclei of the other three kinds of cells. In the liver of rat injected with corticosterone-BSA, the fluorescence seemed to be in a few nuclei of hepatic stellate cells, and appeared as speckles in a few nuclei of the hepatocytes and Kupffer cells. In some seminiferous tubules of rat injected with testosterone-BSA, fluorescence was observed in the nuclei of spermatocytes and spermatids. These results suggest that BSA conjugated with steroid hormone can enter the hormone-target cell nuclei with its antigenicity kept intact, and that the fate of steroid-BSAs is decided at the cell membrane level.

Purification and identification of an estrogen binding protein from rat brain: oligomycin sensitivity-conferring protein (OSCP), a subunit of mitochondrial F0F1-ATP synthase/ATPase

Early studies have suggested the presence in the central nervous system of possible estrogen binding sites/proteins other than classical nuclear estrogen receptors (nER). We report here the isolation and identification of a 23 kDa membrane protein from digitonin-solubilized rat brain mitochondrial fractions that binds 17beta-estradiol conjugated to bovine serum albumin at C-6 position (17beta-E-6-BSA), a ligand that also specifically binds nER. This protein was partially purified using affinity columns coupled with 17beta-E-6-BSA and was recognized by the iodinated 17beta-E-6-BSA (17beta-E-6-[125I]BSA) in a ligand blotting assay. The binding of 17beta-E-6-BSA to this protein was specific for the 17beta-estradiol portion of the conjugate, not BSA. Using N-terminal sequencing and immunoblotting, this 23 kDa protein was identified as the oligomycin-sensitivity conferring protein (OSCP). This protein is a subunit of the FOF1 (F-type) mitochondrial ATP synthase/ATPase required for the coupling of a proton gradient across the F0 sector of the enzyme in the mitochondrial membrane to ATP synthesis in the F1 sector of the enzyme. Studies using recombinant bovine OSCP (rbOSCP) in ligand blotting revealed that rbOSCP bound 17beta-E-6-[125I]BSA with the same specificity as the purified 23 kDa protein. Further, in a ligand binding assay, 17beta-E-6-[125I]BSA also bound rbOSCP and it was displaced by both 17beta-E-6-BSA and 17alpha-E-6-BSA as well as partially by 17beta-estradiol and diethylstilbestrol (DES), but not by BSA. This finding opens up the possibility that estradiol, and probably other compounds with similar structures, in addition to their classical genomic mechanism, may interact with ATP synthase/ATPase by binding to OSCP, and thereby modulating cellular energy metabolism. Current experiments are addressing such an issue.

Androphilic protein studied histochemically in stage D2 prostatic cancer

Androphilic protein in prostatic cancer was histochemically observed with dihydrotestosterone (DHT), R 1881, and mibolerone as ligands. Cancer cells were equally stained with fluorescent R 1881 and mibolerone, and this fluorescence seems to be made up of both the androgen receptor and progestin-binding protein. The staining with fluorescent DHT was weak. Sixty-two Stage D2 prostatic cancer patients were examined with histochemical androphilic protein, and they then received endocrine therapy. The presence of fluorescence of R 1881 was not correlated with grade, but a relationship between the presence of fluorescence and the response to endocrine therapy was noticed 6 months after the start of treatment. Moreover, fluorescence-positive patients showed better survival than fluorescence-negative patients. An examination with fluorescent DHT revealed a similar tendency to that of R 1881, but the frequency of positive fluorescence was lower, indicating that R 1881 is a suitable ligand in this type of study.

Hormone receptors in renal cancer: an overview

The current literature concerning hormone receptors in renal cell cancer is reviewed. Our own results of histochemical determination of estrogen receptors by means of monoclonal antibodies are presented. Based on the studies that have been reviewed and the differing results of the receptor assays, we conclude that there is a very limited basis to apply hormone therapy in renal cell cancer. However, the new immunohisto-chemical methods should be used to resolve the question about the hormone dependency of renal carcinoma.

Whither cytosolic estrogen receptor assays? A comparison of commercially available kits for estrogen receptor assay

Frozen tissue sections and cytosols from 89 specimens of breast and ovarian tumours have been assayed for the presence of estrogen receptor (ER) or related protein using four commercially available monoclonal antibody methods. These were estrogen receptor enzyme immunoassay (ER-EIA), estrogen receptor enzyme immunocytochemical assay (ER-ICA), ER D5 antigen immunoradiometric assay and ER D5 antigen immunocytochemical assay. The results have been compared with those obtained using a standard dextran coated charcoal steroid binding assay (ER-DCC). The correlation coefficient (r) between ER-DCC and ER-EIA results was 0.72 while that of both monoclonal antibody cytosol methods and their respective immunocytochemical assays was 0.66. ER-ICA gave additional valuable information concerning receptor heterogeneity in breast cancer sections. However, the correlation between ER D5 antigen assays and both ER-DCC and ER-EIA was weak (r less than 0.4). We conclude that there are a number of methodological advantages in using the kit systems including their ability to detect receptor presence in small tumour specimens (e.g., "Tru-cut" biopsies) but that their usefulness is limited by the current lack of widely available monoclonal based methods for the concurrent determination of progestogen receptor. We believe that, once these are available, immunocytochemical technology could offer an alternative method of determining the steroid receptor concentration in both ovarian and breast tumours, thus obviating the need for costly and time-consuming cytosolic methods, with their inherent difficulties of quality control.

Steroid-bovine serum albumin conjugates: molecular characterization and their interaction with androgen and estrogen receptors

Conjugates of testosterone-3-carboxymethyloxime (T-3-CMO), testosterone-17-hemisuccinate (T-17-HS), 17 beta-estradiol-6-carboxymethyloxime (E-6-CMO), or 17 beta-estradiol-17-hemisuccinate (E-17-HS) and bovine serum albumin (BSA) with varying steroid:protein ratios were prepared using the mixed anhydride method. Dialysis followed by molecular filtration yielded monomer steroid-BSA conjugates with a molecular weight of 70,000 dalton, and polymer conjugates with molecular weights of 140,000 dalton and higher. When conjugates were prepared with increasing initial steroid:BSA molar ratios the ratio of the obtained conjugates increased, in parallel with a decrease in the relative amount of monomers and an increase in the mean molecular size of polymers. The molecular properties of these conjugates were studied further by polyacrylamide gel electrophoresis (PAGE) in native and denaturing conditions. In native PAGE the monomer fractions showed one main band with a mobility slightly lower than BSA and a faint band corresponding with BSA-dimers. The polymer fractions consisted of a heterogeneous population of protein oligomers with molecular weights varying from 140,000 to over a million dalton. In the presence of sodium dodecylsulphate part of the polymers dissociated into monomers. In buffered aqueous solutions the bulk of the conjugate preparation retained its molecular size and composition, although the generated covalent bonds were found to be liable to spontaneous hydrolysis. Steroid-protein conjugates were shown to contain appreciable amounts of non protein-bound steroids. Binding of T-BSA to androgen receptors in rat ventral prostate cytosol was assayed using LH-20 chromatography and sucrose gradient centrifugation analysis. Binding of E-BSA to estrogen receptors was analysed with rat uterus cytosol using the dextran coated charcoal assay and the sucrose gradient centrifugation technique. Relative binding affinities (RBA) were analyzed in competition experiments using radiolabeled ligands. It was found that the molecular size of the conjugate does not influence its interaction with steroid receptors. Steroid coupled via the 17-position show a higher RBA to receptors than the T-3 or E-6 derivatives. The RBA of T-3-BSA, T-3-CMO, T-17-BSA and T-17-HS appeared to be very low, i.e. between 0.1 and 1.7% of the RBA of dihydrotestosterone. Consequently, high concentrations of conjugate are required to saturate androgen receptor binding sites. Under these conditions involvement of type II and eventually type III binding sites, which show less ligand specificity and lower affinity, may be anticipated preventing exclusive detection of androgen receptors.(ABSTRACT TRUNCATED AT 400 WORDS)

Histochemical estrogen binding. An independent predictor of recurrence and survival in stage II breast cancer

Cox's proportional hazards regression model was used to analyze the prognostic significance of multiple variables affecting recurrence and survival in patients with Stage II breast cancer. Among the variables were biochemical estrogen (ER) and progesterone receptor (PgR) values and results of a histochemical estrogen-binding assay using a fluoresceinated bovine serum albumin-estradiol conjugate where carrier and label were bound at position 17. In 190 cases ER and PgR were not found to be significantly associated with either disease recurrence or patient survival. On the other hand, patients with tumors that were demonstrably "rich" in estradiol ligand conjugate binding by histochemistry experienced both a longer disease-free interval (P less than 0.03) and survival (P less than 0.02) than did patients whose tumors were "poor" in conjugate binding or showed a heterogeneous population of positively and negatively stained cells. A patient with a tumor rich in estrogen binding was five times more likely to survive than a patient with a neoplasm that was poor in estrogen binding by histochemistry. These results indicate that the histochemical technique used provides new and independent parameters for determination of prognosis in Stage II breast cancer.

Histochemical analysis of breast carcinoma metastatic to the orbit

A 62-year-old woman was seen for evaluation of an orbital tumor. Recognition of a relatively rare syndrome of pain, ptosis, and a progressively immobilized globe with enophthalmos suggested the diagnosis of metastatic carcinoma to the left orbit. In this case, this was confirmed by open breast and orbital biopsies, revealing infiltrating lobular breast carcinoma. This is the first reported case where estrogen and progesterone receptors were identified in a metastatic orbital tumor using fluorescent histochemical techniques. This technique was of value in confirming the diagnosis and providing direction for subsequent endocrinologic palliative therapy.

Comparison of histo- and biochemical methods for estrogen and progesterone receptor analysis in primary human breast carcinoma

One hundred and twenty-three primary breast carcinomas have been examined under optimal procedural conditions for presence and quantity of estrogen (ER) and progesterone (PgR) receptors by a histochemical method using hormones conjugated to fluoresceinated bovine serum albumin and by a conventional biochemical (dextran-coated charcoal) assay. The semiquantitative histochemical results for ER and PgR were strongly positively correlated, as were the corresponding quantitative biochemical results, but there was no significant correlation between histo- and biochemical results for ER, nor between the corresponding results for PgR. By generally accepted cut-off limits for positivity there was an equal frequency of ER- and PgR-positive tumors by the histochemical method (71 and 67% respectively), whereas there was a significantly higher frequency of ER- than PgR-positive tumors by the biochemical method (76 and 59%). The qualitative agreement between the two methods was 76% for ER and 61% for PgR, and there was a correspondingly inferior sensitivity and specificity of the histochemical method in comparison with the biochemical method, whose value is clinically validated.

Rapid and sensitive detection of oestrogen receptors in cells and tissue sections by autoradiography with 125I-oestradiol

The presence of receptors for steroid hormones in individual cells and tissue sections was assessed within 4-24 h using dry mount autoradiography with radio-iodinated oestradiol. Low affinity and nonspecific binding of steroids were significantly reduced by washing the cells or sections with diluted antiserum to oestradiol. For cells of the MCF-7 cell line variations in grain density were observed, indicating that cells of the MCF-7 cell line are heterogeneous with respect to their cellular receptor concentrations of oestrogen receptors. Receptor-negative cells, such as peritoneal macrophages, did not retain oestradiol label. In tissue sections of rat and calf uterus, predominant labelling was observed on the endometrial gland cells and stroma. Oestradiol receptor binding in the uterus cytosol for both radio-iodinated and tritiated oestradiol showed the same qualitative characteristics as determined by sucrose gradient sedimentation profiles and a comparable amount of binding sites was found for both labels. The relative binding affinity of 125I-oestradiol compared to [3H]oestradiol is about 70-80%. The dry mount autoradiographic technique as presented can be used for rapid screening of heterogeneity in oestrogen receptor distribution in cells and tissue sections, since this technique reveals differences in receptor concentrations on the single cell level.

Immunocytochemical localization of tissue-bound oestradiol in rat paracervical ganglion

The uterine paracervical ganglion (Frankenhauser's ganglion) contains the terminal neurons of the cholinergic sacral parasympathetic, the short adrenergic sympathetic and the peptidergic (vasoactive intestinal polypeptide-containing) nerves of the internal genitalia. Previous studies have shown that either the number of cells or transmitter content of each of these neuronal systems is altered by variations in steroid hormones. Furthermore, our recent study showed that some component of the rat paracervical ganglion was capable of metabolizing [3H]oestradiol to oestrone and the 2-OH and 4-OH forms of oestrone and oestradiol. The present study employs the peroxidase-anti-peroxidase immunohistochemical method to localize oestradiol in rat paracervical ganglia. Specific reaction product was identified in (1) cytoplasm and some nuclei of principal ganglion cells, (2) cytoplasm of large vacuolated ganglion cells, (3) cytoplasm of 'small intensely fluorescent' cells and (4) some nerve fibres in ganglia from animals in oestrus. The cytoplasm of principal neurons and some nerve fibres exhibited specific staining for oestradiol in dioestrus and pro-oestrus. No oestradiol was localized in ganglia excised from animals in metoestrus. Preincubation in oestradiol before fixation was necessary for specific localization of oestradiol; treatment of tissues with oestradiol after fixation was not required. These results are not consistent with binding of oestradiol to the classical oestrogen receptor. The resistance of oestradiol to organic solvent extraction suggests that oestradiol is covalently bound to tissue proteins. Such covalently bound oestradiol has been reported as a by-product of tissue metabolism of oestradiol via P-450 enzymes.

Fluorescent ligands, used in histocytochemistry, do not discriminate between estrogen receptor-positive and receptor-negative human tumor cell lines

A cell line containing estrogen receptors (MCF-7) and a cell line lacking estrogen receptors (PC-93) were used for a comparison of biochemical and histochemical procedures to detect estrogen receptors. We evaluated three different fluorescent estrogen derivatives: 17 beta-estradiol-6-carboxymethyloxime-bovine serum albumin-fluorescein isothiocyanate, 17 beta-estradiol-17-hemisuccinate-fluoresceinamine, and coumestrol. The main results were: The relative binding affinities of these ligands for the estrogen receptor were between 0.1 and 2% of the affinity of estradiol. Fluorescent staining of the cells showed no relation to the presence of estrogen receptors. Staining was not suppressed with excess estradiol-17 beta, which is known to prevent binding of low affinity ligands to estrogen receptors. Cells with intact membranes were not stained after treatment with the albumin-linked estrogen derivative; only cells with damaged cell membranes were stained. Treatment of cells with 17 beta-estradiol-17-hemisuccinate-fluoresceinamine resulted in a fluorescent labeling of the cytoplasm in intact and artificially damaged cells. Coumestrol caused only fluorescence of the cytoplasm in intact cells. It is concluded that estrogen receptors cannot be detected with these low affinity ligands. Fluorescence of these cells is probably due to binding of the ligands to low affinity binding sites. The presence of these low affinity binding sites appears not to be related to the presence or absence of estrogen receptors and can therefore not be used to discriminate between estrogen receptor-positive and receptor-negative tumor cells.

Radiochemical determination of estrogen receptors in cryostat sections of target tissues

A radioreceptor assay on unfixed cryostat sections has been developed. Mounted and dried sections were incubated with radiolabeled estradiol in the absence and presence of an excess of diethylstilbestrol and washed with buffer. Binding of radiolabel to sections was measured by direct liquid scintillation counting. Also protein-bound radioactivity which eluted from the sections was determined with a dextran-coated charcoal assay. Parallel sections were used for histological staining and protein determination. Scatchard analysis showed the presence of specific saturable binding sites for estradiol with dissociation constants in the 0.1-1.5 nM range. It is concluded that these high affinity and limited capacity (type I) binding sites represent estrogen receptors. The ligand-binding activity of section-bound estrogen receptors did not decrease upon dry storage up to 20 h at 4 or 23 degrees C prior to assay. During aqueous incubation a significant amount of receptor, representing about 40-60% of the total tissue content, elutes from the sections. Steroid specificity was proven by incubation with excess androgen, progestogen or corticoid instead of diethylstilbestrol or estradiol. With these ligands no significant competition was found. Tissue specificity was demonstrated by a very low level of specific estradiol binding to cryostat sections of rat skeletal muscle, spleen and intestine and by a moderate level in rat liver.

Estrogen, progesterone, and androgen-binding sites in renal cell carcinoma. Observations obtained in Phase II trial of flutamide

A Phase II disease-oriented drug trial using flutamide (4'-nitro-3'trifluoro-methylisobutyranilide) 250 mg by mouth three times a day was undertaken in 28 patients with advanced, bidimensionally measurable renal cell carcinoma. Of 25 adequately treated cases, 1 (4%, 95% confidence limits 0-12%) had a partial remission lasting 9+ months, and 2 had stabilization of disease lasting 6 and 15 months, respectively. Flutamide demonstrated no significant antitumor activity in patients with disseminated renal cell carcinoma. Including patients entered in this study, 62 specimens were evaluated for steroid binding sites using a fluorescent method: 33 of 62 specimens assayed showed no hormone-binding sites, and only 12 cases had androgen binding. Of the 12 of 23 patients receiving flutamide who were biopsied and had an adequate sample for steroid-binding site determination, estrogen binding was demonstrated in 6, androgen binding in 3, and progesterone binding in 4. Since this study did not obtain a sufficient number of cases with androgen-binding positivity, the possible efficacy of flutamide in such cases cannot be excluded.

Estrogenicity of coumestrol in the mouse: fluorescence detection of interaction with estrogen receptors

The estrogenicity of coumestrol, a fluorescent phytoestrogen, has been examined in murine uteri. Coumestrol competed with 17 beta-[3H]estradiol for binding to cytoplasmic estrogen receptors, caused cytoplasmic estrogen receptors to associate with chromatin in the nucleus, and induced progesterone receptors. By use of size-exclusion high-performance liquid chromatography (SEHPLC), the interaction of coumestrol with estrogen receptors was examined directly by monitoring the fluorescence associated with macromolecules having properties characteristic of estrogen receptors. These analyses were made possible by the addition of dimethylformamide to the elution buffer, at a concentration (7.5%) which improved recoveries but did not interfere with estrogen receptor binding. It was possible to detect fluorescent coumestrol at approximately 0.5 nM. All determinations were performed with preparations in which estrogen receptor activity was 3-10 nM. Exposure of these preparations to coumestrol (50 nM) resulted in the elution of increased fluorescent activity in the regions where estrogen receptors eluted during SEHPLC. This fluorescent activity was reduced when diethylstilbestrol, 17 beta-estradiol, hexestrol, or tamoxifen was present as a competitor (2 microM) but was unaffected by testosterone or progesterone. Diethylstilbestrol reduced fluorescence below endogenous base lines and thereby displayed a fluorescence quench property which was not observed with other ligands. When hepatic and renal estrogen receptor preparations were used, the injected receptor activity was observed to be the major limiting factor in detecting the interaction of coumestrol with estrogen receptors. These observations are relevant to attempts to visualize estrogen receptors in tumor cells and demonstrate that accepted biochemical criteria for ligand-receptor interaction can be satisfied when fluorescent ligands are examined.

Histochemical androgen binding assay in prostatic cancer

A group of 60 patients with clinical stage C or D prostatic carcinoma was evaluated for androgen binding using a histochemical assay. Of the patients positive for binding 82 per cent either responded to hormonal therapy or remained stable, while 100 per cent of those negative for binding had progression. Of 6 men whose cancer was considered borderline positive 2 manifested a partial clinical response, while 4 had progression.

Fluorescent histochemical demonstration of estrogen and progesterone binding in giant cell tumors of bone: preliminary observations

Hormonal receptors of giant cell tumors (GCTs) have not been previously reported. Five cases of GCT of bone were analyzed for estrogen and progesterone binding. Frozen sections were studied by a histochemical method, using 17-beta-6-CMOBSA-FITC and 11-alpha-hydroxyprogesterone-HS-BSA-TMRITC. Cytoplasmic fluorescence with estradiol-BSA-FITC was seen in stromal cells of all five tumors; three also showed cytoplasmic staining with progesterone-BSA-TMRITC. No fluorescence was seen in the giant cells. Two cases were also analyzed by a dextran-coated charcoal cytosol assay. No estrogen or progesterone receptor was detected by cytosol assay. This study suggests that the estrogen and progesterone binding is present in GCT of bone, possible to low-affinity sites rather than high-affinity receptors. Further investigation of hormonal receptors of GCTs of bone is warranted.

Fluorescent androgen derivatives do not discriminate between androgen receptor-positive and -negative human tumor cell lines

For the evaluation of histochemical procedures for detection of androgen receptors, three human tumor cell lines have been used: PC-93 and NHIK-3025, both biochemically characterized as androgen receptor-positive, and EB-33, biochemically characterized as androgen receptor-negative. The binding of three fluorescent ligands, testosterone-17 beta-hemisuccinate-bovine serum albumin-fluorescein isothiocyanate, testosterone-17 beta-hemisuccinate-fluoresceinamine, and 5 alpha-dihydrotestosterone-17 beta-hemisuccinate-fluoresceinamine, to the cells was evaluated. The relative binding affinities of the ligands for the androgen receptors were low (less than 5% when compared to methyltrienolone). Treatment of the cells with the androgen-fluoresceinamine derivatives resulted in a fluorescent labeling of the cytoplasm in both intact and "freeze-damaged" cells of the three cell lines. This staining was independent of the presence of receptors. Nuclei were not stained. Incubation of intact cels with the protein-linked conjugate did not result in significant cellular fluorescence. Only cells with damaged membranes showed a positive histochemical reaction, both in nucleus and cytoplasm, irrespective of the receptor content of the cells. The fluorescence intensity was not suppressed with excess 5 alpha-dihydrotestosterone or methyltrienolone, which are known to prevent binding of low affinity ligands to androgen receptors. From these results it is concluded that androgen receptors cannot be detected by these fluorescent ligands with low affinity for the receptor. The observed fluorescence of the cells is therefore due to binding of the ligands to other binding sites. The visualization/histochemical demonstration of these binding sites does not appear to be related to the presence of androgen receptors.

Electrocautery: effects on steroid receptors in human breast cancer

The determination of steroid receptors in human breast cancers has assumed increasing importance over the past several decades. Improper handling of the specimens could affect results obtained. This study details the effects excessive levels of heat that occur with the use of electrocautery can have on steroid receptor quantities and localization. Twelve resected primary and metastatic human breast cancers were analyzed for cytoplasmic and nuclear receptors by biochemical analysis. In addition, steroid binding was determined by direct fluorescent histochemical techniques. To a portion of each resected specimen a Boviec was applied to simulate electrocautery resection. Analysis of the different portions of the same tumor revealed that there was a decrease in measurable cytoplasmic receptor in all cauterized specimens and a concomitant increase in the nuclear receptor. A similar shift in steroid binding was noted in all the specimens analyzed by fluorescent histochemical techniques. The results of this study show that the application of excessive heat to human breast cancers will lead to false negative biochemical steroid receptor determination by shifting the receptors intranuclear.

Cytofluorometric analysis for estrogen receptors using fluorescent estrogen probes

Estrogen receptor (ER) analysis of breast cancer tissue has been shown to be very useful in predicting which patients will respond to hormone therapy and have a better prognosis. The ER assay is, however, tedious and time consuming. Measurement of ER by flow cytometry would be rapid and based on either an average fluorescence-E2 probe intensity per cell or the percentage of the ER+ cells per cell suspension. Analysis of E2 modified structures for relative binding affinity to the ER determined by competition studies and for fluorescence uptake into cell suspensions determined by flow cytometry was performed. Lack of high affinity to the ER and purity of the compound were major problems for the fluorescein-labeled estrogen probes. Base hydrolysis of the ester linkage in fluorescein-E2 compounds demonstrated by HPLC very little estradiol derivative in the parent compounds compared to total components present. A second type of fluoresceinated estrogen which has a peptide bond between the steroid and the chromophore was also tested. It was less contaminated but was unable to get into the cell and showed no binding activity to the ER. A pure plant fluorescent estrogen, coumestrol, has Ka of 6 X 10(8) M-1 for the ER and is a single component as determined by HPLC. Specific fluorescent uptake of coumestrol was performed on ER+ and ER- viable cell suspensions. When these coumestrol-cell suspensions were excited at 350-360 nm and the blue emission was measured using flow cytometry, the result was a fluorescence uptake that was not highly displaceable by excess nonfluorescence E2 probes.(ABSTRACT TRUNCATED AT 250 WORDS)

Estrogen and progesterone receptors of human endometrial cells in vivo and in vitro: comparative results of radiochemical and histochemical assays

Oncopathologists have been developing histochemical methods of sex steroid receptor determination, essential in therapy selection in breast cancer, based on the binding of labeled hormone to receptor. We have applied the fluorescent hormones available commercially from Lee to endometrium. Our purpose was to compare biochemical and histochemical results, both in fresh tissue and in endometrial tissue cultures. We wished to examine the ability of the technique to determine subcellular localization of hormone binding and to trace the hormone-receptor pathway to the chromatin. Eleven fresh normal endometrial specimens, in culture for 3 months, were used for the determination of receptors. As a control we also used cells from 4 human carcinoma cell lines. In fresh tissue, histological patterns were similar to those described in breast cancer but there was little correlation with radiochemical values. In cultured cells also, there was no similarity between the two techniques. Morphologically the labeled hormone was unable to enter the living cell. After fixation it never got through the nuclear membranes. Moreover, the fluorescent cytoplasmic feature was fibrillar and reticular, which could evoke a non specific fixation on the cytoskeleton. We concluded that this molecule is not useful for subcellular localization of hormone-receptor complexes.

Are fluorescein-conjugated androgens appropriate for a histochemical detection of prostatic androgen receptors?

Histochemical fluorescence techniques could be of great value in order to assay androgen receptors (AR), particularly in punch biopsies from human prostatic carcinoma (PCA). Therefore, prostatic tissue was examined for specific binding of fluorescein-labeled 5 alpha-dihydrotestosterone derivatives (FDHT) to AR. Using a 17 beta-fluoresceinated DHT derivative (17-FDHT), variable fluorescence was found in human and rat prostates at high 17-FDHT concentrations. This fluorescence could be blocked by unlabeled DHT in 11 and 73% of human and rat prostatic tissue, respectively. Control studies of receptor and organ specificity were conducted and showed that preheated slices from rat prostates displayed no decrease of fluorescent staining. No difference in fluorescence intensity could be seen between prostates from castrated and uncastrated rats. Unstained tissue slices frequently showed a considerable intensity of autofluorescence. An appreciable amount of fluorescence in both rat liver and spleen was found. From these results and various general methodical problems inherent in fluorescent receptor assays, we conclude that the fluorescence techniques described are inappropriate for demonstration of AR.

Studies with steroid-fluorescein conjugates on oestrogen target tissues

Steroid--fluorescein amine and steroid-BSA-fluorescein-isothiocyanate conjugates have been prepared and their ability to bind to oestrogen receptors assessed in competitive binding studies. The binding of all the fluorescent conjugates to uterine cytosol proteins was low when compared with either oestradiol or diethylstilboestrol. A comparative study was carried out to assess the relationship between oestrogen receptor content, determined biochemically, and histochemical localisation of the oestrogen binding components on thin sections of rat uteri, DMBA-induced mammary tumours and also human breast tumour tissue taken at mastectomy. The data indicate that in thin sections of tissue all of these conjugates appear to bind not to the classical oestrogen receptor moiety but to other oestrogen binding proteins.

Correlation of histochemical and biochemical analyses of androgen binding in prostatic cancer: relation to therapeutic response

A histochemical technique for the detection of androgen binding in prostatic cancer was performed on specimens from 108 patients and compared with a biochemical method in a double blind study of 77. Statistical analyses showed a significant agreement between the two assay systems for the qualitative and quantitative presence or absence of specific androgen binding, as well as for the subcellular localization of binding in nucleus and/or cytoplasm. Although the number of cases studied was too small for statistical analysis, there appeared to be good correlation between histochemical androgen binding results and clinical response, or lack of response to hormonal manipulation in 20 patients with State C and Stage D carcinoma. No correlation was evident between androgen binding and tumor grade or clinicopathologic stage of disease of either histochemistry or biochemistry.

Estrogen receptors in human breast cancer. II. Correlation between the histochemical method and biochemical assay

The present study defines criteria for determining the presence of estrogen-receptors in human breast carcinomas demonstrated by a histochemical assay using 17 beta-estradiol-carboxy-methyl-oxim-bovine serum albumen-FITC. The criteria were: 1) the percentage of cells showing fluorescence; 2) the intensity of the fluorescence observed, and 3) the percentage of epithelial structures in tissue specimens. Using these predefined criteria in 132 human breast carcinomas as 91.6% agreement was found between the results of the histochemical assay and those of the biochemical Charcoal method. The main causes of disagreement (7 of the 11 cases) were sampling errors between the tissue specimens used for the histochemical and biochemical assay, and an insufficient percentage of epithelial structures (less than 15%) to allow biochemical identification of estrogen receptor activity. In the hands of pathologists with experience of the field of histochemistry this histochemical assay may be the method of choice for the assessment of estrogen receptors.

Immunohistologic and histochemical methods for detection of steroid binding in breast cancer: a reappraisal

A review of the current literature on immunohistologic and histochemical methods for the detection of steroid hormone binding sites in breast cancer, reveals that many, but not all of the criteria for establishing hormone-receptor binding interactions have been met. These include tissue specificity, binding between labeled ligands and soluble receptor in vitro, correlations between histochemical and biochemical assays, as well as between histologic procedures and tumor hormone responsiveness. However, histochemical binding phenomena do not appear to follow classical receptor dogma in regard to the concentration of ligand required, or specificity of binding as determined by competitive binding assays. It is concluded that these histologic techniques may be detecting classical receptor that may be reacting differently than would be expected from biochemical analyses, Types II and III binding sites, and/or organelle and membrane-bound receptors. Certainly no current method should presently be promoted as a laboratory method for the detection of classical receptor. New immunocytologic procedures employing specific, antireceptor sera currently under development, may obviate many of the criticisms leveled against earlier methods.