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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 17beta-estradiol-6-carboxymethyl-oxime-bovine serum albumin--fluorescein isothiocyanate conjugate is prepared by attaching on the average 11 moles of the fluorescein dye and 24 moles of the steroid hormone to each mole of the protein carrier. This fluorescent estradiol conjugate is used as a tracer to detect estrogen receptor of human mammary cancer cells in frozen sections. The cytochemical findings indicate that mammary carcinomas are composed of heterogeneous populations of receptor-positive and receptor-negative cancer cells in varying proportions and probably should be classified according to the percentages of receptor-positive cells in the cancer cell populations for better correlation with endocrine therapies.
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PMID:Cytochemical study of estrogen receptor in human mammary cancer. 8 Sep 58

Unselected, consecutive surgical specimens from 120 women with cancer of the breast were subjected to histochemical assay for the presence of estrogen receptor. A fluoresceinated bovine serum albumin--estradiol conjugate was used that linked estradiol at position 17 and contained 5 mol fluorescein and 4 mol estradiol per mole albumin. Simultaneous competitive binding studies with excess unlabeled estradiol, diethylstilbestrol, and the antiestrogen nitromifene citrate were regularly performed. Results were compared to those obtained by the dextran-coated charcoal receptor assay. Three specimens were necrotic, two others thawed, and two lacked sufficient protein for biochemical analysis. One specimen did not contain tumor, and 11 others showed a predominant nuclear staining pattern. Nuclear receptor was not assayed biochemically. Comparison of results in the remaining 101 cases showed agreement in 92%. The precedure is uncomplicated, economical, and could be performed and interpreted in any pathology laboratory.
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PMID:An improved histochemical method for detection of estrogen receptors in mammary cancer. Comparison with biochemical assay. 37 38

Benign nevi, dysplastic nevi, and primary and metastatic malignant melanomas were evaluated for the presence of sex hormone binding and estrogen receptor protein. We have confirmed the observation of Ellis et al. that some pigmented lesions possess sex hormone-binding proteins. We could not demonstrate a true estrogen receptor in any benign nevi, dysplastic nevi, primary melanomas, or metastatic melanomas. Thus the ability to bind estrogen or progesterone does not correlate with the presence of a true estrogen receptor. Lack of nuclear estrogen receptors suggests that the influence of estrogen on the pathophysiology of melanoma or of benign melanocytic nevi may not be significant.
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PMID:Absence of estrogen receptors in dysplastic nevi and malignant melanoma. 221 19

Two studies were carried out to examine possible causes of the variability that occurs in studies on estrogen receptors in sheep. In the first study, the concentration of estrogen receptors in the uterus of a group of 16 ovariectomized ewes was inversely related to their live weight (r = -0.52, p less than 0.05). A second study examined 8 ovariectomized controls and 7 ewes that were permanently infertile after prolonged exposure to estrogenic clover pasture. The concentration of estrogen receptors in the pituitary of these ewes was inversely related to a measure of body fatness (r = -0.67, p less than 0.05), and there were no differences between control and clover-affected ewes. In addition to the classical estrogen receptor with a dissociation constant of 0.03 X 10(-9) mole/L, there were secondary binding sites with dissociation constants of about 0.9 X 10(-9) mole/L in the pituitary. The amount of this binding varied among sheep and appeared to increase as the cytosol was diluted. It is suggested that a failure to distinguish the presence of these sites may have led to apparent differences between experimental groups in the amount of affinity of receptors in previous studies. The effect of body condition on the number of cytosolic receptors may also have confounded previous studies.
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PMID:Measurement of estrogen receptors in the ovariectomized ewe is affected by body condition and secondary binding sites. 381 96

The X-ray crystallographic structural determinations of synthetic estrogens and antiestrogens provide reliable information on the global minimum energy conformation of these molecules or a local minimum energy conformation that is within 1 or 2 kcal/mole of the global minimum. In favorable cases, state-of-the-art molecular mechanics calculations provide quantitative agreement with X-ray results and information on the relative energy of other local minimum energy conformations not observed crystallographically. Because the conformation of diethylstilbestrol (DES) observed in solvated crystals has an overall conformation and dipole moment more similar to estradiol it is the form more likely to bind to the receptor and produce hormone activity. Either phenol ring of DES can successfully mimic the estradiol A-ring in binding to the receptor. Indenestrol A (INDA) and indenestrol B (INDB) have nearly identical fully extended planar conformations. Either the alpha or gamma rings of these compounds may mimic the A ring of estradiol and compete for the estrogen receptor. Although there are eight distinct ways in which molecules of a racemic mixture of INDA or INDB can bind to the receptor, not all of them may be able to elicit a hormonal response. This may account for the reduced biological activity of the compounds despite their successful competition for receptor binding. The minimum energy conformations of Z-pseudodiethylstilbestrol (ZPD) and E-pseudodiethylstilbestrol (EPD) are bent in a fashion similar to that of indanestrol (INDC). These molecules have good binding affinity suggesting that the receptor does not require a flat molecule. Therefore these conformations would appear to be compatible with receptor binding, but only the Z isomer has an energetically allowed extended conformation that accounts for its observed biological activity relative to DES.
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PMID:Molecular conformation, receptor binding, and hormone action of natural and synthetic estrogens and antiestrogens. 390 70

This study was performed as an initial step to evaluate the possible effects of steroid hormones on benign nevi. Cytoplasmic receptors for estrogen were found in nine (41%) of 21 benign nevi from melanoma patients. Ten (37%) of 27 melanoma tumor tissues also had receptor for estrogen. Benign nevi from 17 normal persons had no estrogen receptor activity. The similar incidence of estrogen receptor in benign nevi from melanoma patients and in melanoma tissue itself, compared with the absence of receptor in benign nevi from a normal population, suggest that steroid hormones such as estrogen may represent a molecular alteration associated with a potential pathophysiologic transformation of a benign nevus to its malignant counterpart.
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PMID:Incidence of estrogen receptor in benign nevi and human malignant melanoma. 739 87

The level of parathyroid hormone-related protein (PTHrP) expressed in breast cancer tissue is closely related to the incidence of bone metastasis. We examined the PTHrP mRNA expression in breast cancer tissues by coamplification polymerase chain reaction (PCR) in mole ratio to internal standard beta-actin mRNA. The PTHrP expression was higher in premenopausal patients than in postmenopausal patients (P < 0.05). More pronounced difference by menopause found in estrogen receptor (ER) positive groups (P < 0.001) indicated that the PTHrP expression in breast cancer tissue is hormonally regulated and might be altered by endocrine agents. To clarify the changes of PTHrP expression by endocrine therapy of breast cancer, we measured PTHrP expression in the breast cancer tissue incubated for 24 h with 1 x 10(-8) M of estradiol (E2), 1 x 10(-6) M of tamoxifen (TAM) and 1 x 10(-5) M of medroxyprogesterone acetate (MPA). The PTHrP expression was decreased significantly by MPA (P < 0.005), while E2 and TAM did not change the PTHrP expression. Progesterone receptor (PgR) mRNA expression was also examined to confirm that the breast cancer tissue responds to E2 and TAM. The results were well compatible with the better therapeutic effect of MPA reported for the treatment of breast cancer with bone metastases. As a potential candidate for the receptor that mediates the suppressive effect of MPA, androgen receptor (AR) is suggested most probable. Present results also demonstrated that the clinical response of individual tumors is closely associated with the early in vitro changes of gene expression detected in the cancer specimen.
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PMID:Suppression of parathyroid hormone-related protein messenger RNA expression by medroxyprogesterone acetate in breast cancer tissues. 1051 39

Biochemical markers improve the classification and staging of breast cancer and may refine management decisions if it can be shown that they correlate with accepted prognostic factors or patient outcome. Using phosphorus-31 magnetic resonance spectroscopy ((31)P MRS), we determined the phospholipid content of 43 malignant breast tumors, correlating the profiles with specific histopathologic and clinical features and hormone receptor status. Among the 14 phospholipids identified, the mean mole percentage of sphingomyelin, phosphatidylcholine, phosphatidylserine, phosphatidic acid, phosphatidylglycerol, and alkylacylphosphatidylcholine predicted cellular infiltration, infiltration type, elastosis, lymphatic invasion, perineural invasion, necrosis, and estrogen receptor positivity. (31)P MRS phospholipid profile data provide statistical correlations among histologic features and molecules known to play important roles in cellular communication, regulation, and processes unique to malignant tissues.
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PMID:Malignant breast tumor phospholipid profiles using (31)P magnetic resonance. 1180 43

Nitrotyrosine (NO2Y) is a global marker of protein modification by reactive nitrogen species such as peroxynitrite derived from nitric oxide (NO). Because NO and its derivatives are postulated to enhance carcinogenesis, we used stable isotope dilution mass spectrometry to measure the levels of NO2Y in 30 samples of human breast cancer of varying pathologic types. In the samples tested, the NO2Y levels were generally low (average of 14.1 +/- 9.2 micromol NO2Y per mole of tyrosine). Breast cancers with a high microvascular density, however, had a significantly higher average level of NO2Y than tumors with a low microvascular density (20 v.s. 10 micromol NO2Y per mole of tyrosine, p = 0.007 by two-tailed t-test, assuming unequal variances of two samples). There was no apparent association between NO2Y levels and the differentiation of the tumors, tumor aneuploidy, estrogen receptor status, HER-2 expression, lymph node status, or infiltration of the tumors by neutrophils or eosinophils. When the tissues were stained by immunohistochemistry for NO2Y, the NO2Y was localized predominantly within inflammatory cells located immediately adjacent to blood vessels at the edges of the tumors. NO2Y was generally not evident within the tumor cells or inflammatory cells in the stroma. We conclude that low levels of reactive nitrogen species are located predominantly within inflammatory cells near blood vessels of breast cancer and that higher NO2Y levels are associated with an increased density of blood vessels. Our findings, therefore, support a possible association between inflammatory cells and reactive nitrogen species in modulating microvascular density at the edges of breast cancer.
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PMID:Association between nitrotyrosine levels and microvascular density in human breast cancer. 1220 16

Estrogen levels increase during pregnancy and clinical evidence has long suggested that melanocytes are estrogen-responsive. We hypothesized that nevi from pregnant patients would exhibit increased expression of estrogen receptor beta (ERbeta) and thus enhanced potential to respond to altered estrogen levels. Normal, dysplastic and congenital nevi (n = 212) were collected from pregnant and non-pregnant women ranging from 18 to 45 years of age. Immunohistochemical staining was performed on these nevi using antibodies specifically directed against estrogen receptor alpha (ERalpha) and ERbeta. ERalpha was not observed in any lesions; thus, ERbeta was the predominant estrogen receptor in melanocytic cells from all types of nevi. Enhanced positivity for ERbeta in normal nevi during pregnancy was noted, compared with non-pregnant controls including nevocytes residing in both the epidermal and dermal micro-environments (P = 0.005 and P = 0.001 respectively). Nevi with increasingly melanocytic atypia showed increased ERbeta in nevocytes nested within the epidermis. No additional increase in ERbeta in atypical nevi was observed during pregnancy. For normal and congenital nevi, regardless of pregnancy status, dermally associated nevocytes tended to have greater ERbeta immunoreactivity. Significant decreases in ERbeta immunoreactivity were observed in congenital nevi from pregnant women compared with normal and dysplastic nevi from pregnant women. Our data suggest that nevi possess the capacity to be estrogen-responsive. Factors such as pregnancy and degree of atypia are associated with enhanced ERbeta with the exception of congenital nevi where the melanocytes were unique in their response to pregnancy.
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PMID:Estrogen receptor beta expression in nevi during pregnancy. 1817 52


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