Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Normal mammary gland cells are sensitive to a number of hormones, of which estrogen and prolactin exert the most obvious effects. Some breast cancer cells are also sensitive. Cytoplasmic receptor sites for each hormone are responsible for the interaction between the hormone and the cell. The presence of estrogen receptor has been especially studied in humans. Data collected from several sources are reviewed. The prese nce of estrogen receptors has been assayed in 154 primary breast tumors and 72 metastatic breast tumors for correlation with response to endocri ne therapy. Positive values were found in 70% of primary and 58% of metastatic specimens. Of 211 treatment trials, ablative therapy produced objective tumor regressions in 33%. Of the 94 trials with negative receptor values, only 8 were successful while 59 of the 107 trials in patients with positive receptor values succeeded. In those with borderline tumor receptor, values had a 30% response. With additive therapy, 34% of 170 trials showed tumor regression. Of these, 82 had negat ive receptor values but 8% were successful, whereas of 85 with positive receptor values, 60% were favorable. With miscellaneous therapy, 27% of 55 trials gave responses to a variety of endocrine therapies, including antiestrogens. The 32 with negative receptor values gave 16% of favorable responses whereas 43% of 23 trials in those with positive receptor values succeeded. Estrogen receptor assays performed routinely would spare patients with negative results from unnecessary major ablative therapy. Of those with positive findings, 55-60% might be benefited. The fact that all with positive receptor values do not respond is attributed to the fact that this is only part of the hormonal control system. Other biochemical lesions are assumed to have occurred in patients when endocrine therapy fails despite positive estrogen receptor levels as measured.
 ...
PMID:Steroids and human breast cancer. 17 10

Human breast cancer can be divided into a group that contains specific receptor sites for estrogen and a group without such specific estrogen-binding sites. The presence of specific estrogen receptors in some tumors indicating hormonal dependency has been shown to be of predictive value for endocrine treatment. This would greatly improve therapeutic planning for patients with breast cancer. Tumor tissue from 52 patients was investigated for content of both cytosol estrogen and estrogen receptor. In addition, the total tumor estrogen was also determined in 14 of these tumors. The results of this investigation show two distinct groups: one group containing both estrogen receptor and estrogen and a second group with no receptor but with measurable amount of estrogen. Tumors with estrogen receptors have higher tissue levels of estrogen than tumors without specific estrogen receptor. Even in the absence of estrogen recptor, however, most tumor tissue examined contained a measurable amount of estrogen.
 ...
PMID:Estrogen and estrogen receptors of breast cancer. 17 22

The determination of estrogen receptor (estrophilin) in human breast cancers, both primary and metastatic, can furnish information useful to the clinician in his choice of the optimal therapy for the individual patient with advanced disease. Of patients with significant tumor estrophilin levels, most, but not all, will respond favorably to endocrine therapy. Women whose cancers lack sufficient amounts of estrophilin have little or no chance of benefit from endocrine ablation or hormone administration and probably should be treated directly by alternative types of therapy.
 ...
PMID:Estrogen receptors in hormone-dependent breast cancers. 17 22

The metabolism of 7alpha-3H-dehydroepiandrosterone was studied in six human breast carcinomas in vitro. All mammary tumors transformed DHA to testosterone, dihydrotestosterone, 5alpha-androstane-3alpha, 17beta-diol and 5alpha-androstane-3,17-dione. Of the tumors investigated, three estrogen receptor-negative tumors converted DHA to estradiol and only one estrogen receptor-positive tumor produced estradiol from DHA. Observations on the relationship of androgen metabolism and hormone dependency are discussed.
 ...
PMID:Metabolism of dehydroepiandrosterone by hormone dependent and hormone independent human breast carcinoma. 17 46

The tumors from approximately 50% of patients with breast cancer contained estrogen receptor (ER). ER appeared more often and at higher levels in the tumors of postmenopausal women. Eleven out of 12 patients who had multiple ER assays from various metastatic sites showed no significant discrepancies in ER values. ER level appears to decrease as the duration of metastatic cancer increase. Patients with ER in the tumor more frequently have bone metastases than those without ER. Visceral metastases occurred more often with ER negative patients and appeared to have a more malignant course with significant shorter survival.
 ...
PMID:Estrogen receptor and natural course of breast cancer. 17

The urinary excretion of corticosteroid sulfates and free cortisol were determined in 150 breast cancer patients. Four of 60 cases of early breast cancer (7%) and 26 of 90 patients with advanced breast cancer (29%) showed an elevated urinary corticosteroid sulfate excretion. Urinary free cortisol was usually normal. Estrogen receptor assays were performed on tumor samples from 67 breast cancer patients; 24 were from primary lesions obtained at mastectomy, 3 from inoperable primaries in patients with systemic metastases, and 40 from metastases. Sixteen of the primary breast cancers (67%), 26 of the metastases (65%) and 1 of the 3 inoperable primaries contained estrogen receptors. With 2 exceptions, patients with an increased urinary corticosteroid sulfate excretion also had estrogen receptor-containing tumors.
 ...
PMID:Corticosteroid sulfate excretion and estrogen receptors in breast cancer. 17 41

We have identified receptors for glucocorticoids, progestins, and androgens in a human breast tumor cell line (MCF-7) known to have estrogen receptor. Sucrose density gradients show that MCF-7 cytosol contains approximately 100 fm/mg protein estradiol (E2-3H) receptor, more than 300 fm/mg protein progesterone receptor (measured with R5020-3H), about 40 fm/mg protein 5alpha-dihydrotestosterone (5alpha-DHT-3H) receptor, and 800 fm/mg glucocorticoid receptor (measured with dexamethasone-3H). Dissociation constants obtained by Scatchard analyses were approximately 0.6 x 10(-10)M (E2), 1 x 10(-9)M (R5020), 2.8 x 10(-10)M (5alpha-DHT) and 8 x 10(-9)M (dexamethasone). No cross competition was found for estrogen receptor, but progestins competed for androgen and glucocorticoid binding. The androgen, but not the glucocorticoid, partially competed for R5020 binding to progesterone receptor. This first demonstration of 4 classes of steroid receptors in human breast cancer means that MCF-7 may be an excellent in vitro model for studying the mechanism of tumor response to endocrine therapy as well as the complex relationships between binding and biological actions of these hormones.
 ...
PMID:MCF-7; a human breast cancer cell line with estrogen, androgen, progesterone, and glucocorticoid receptors. 17 27

Six patients with metastatic carcinoma of the breast underwent mediastinoscopy to obtain tissue for estrogen receptor analysis and pathologic confirmation of metastatic tumor. The indication for mediastioxcopy was an abnormal mediastinal accumulation of gallium in five patients, only two of whom had an abnormality noted on tomography. All six patients had tumor recovered by mediastinoscopy as demonstrated by pathologic examination and/or estrogen receptor assay, Therefore, the diagnosis of mediastinal metastases in breast cancer may be suggested by either chest roentgenograms, mediastinal tomography, or gallium scintigraphy. Mediastinoscopy is a safe, effective procedure capable of establishing the diagnosis of metastatic carcinoma of the breast and of procuring sufficient tissue for estrogen receptor analysis in patients without more readily accessible sites of metastases.
 ...
PMID:Mediastinoscopy: a diagnostic aid in metastatic carcinoma of the breast. 17 83

Estrogen and prolactin receptor concentrations were measured in 24 carcinogen-induced rat mammary tumors and correlated with the tumor response to host ovariectomy or hypophysectomy. It was found that essentially all of the tumors contained some specific estrogen receptor, and all but three contained prolactin receptor. The values for each receptor comprised a continuum from very low to relatively high concentrations, suggesting that previous considerations of hormone dependence on the basis of presence or absence of hormone receptors may be oversimplified. The concentration of each receptor tended to be lower in the hormone-independent than in the hormone-dependent tumors, but there were a number of hormone-independent tumors with higher receptor levels than some of the hormone-dependent tumors had. A better correlation of tumor response to endocrine ablation resulted from a combination of the 2 receptor levels than from either receptor concentration alone. These results suggest that there is a complex relationship between mammary tumor response to endocrine ablatin and levels of estrogen and prolactin receptors and that some tumors may be dependent upon 1 or both of these hormones for growth.
 ...
PMID:Estrogen and prolactin receptor concentrations in rat mammary tumors and response to endocrine ablation. 17 95

The "ovarian-dependent" rat mammary tumors, induced by 9,10 dimethyl-1,2-benzanthracene, were assayed for their estrogen receptor content by dextran-coated charcoal adsorption and sucrose gradient ultra-centrifugation. The estradiol receptors bound estrogens with a high affinity (KD approximately 0.25 nM), limited capacity and high specificity, and sediment at 8 S in a sucrose gradient. The cytosol receptors were transferred to the nucleus after binding to estrogens either in vivo or in vitro. The tumor area regressed by 70% during the first 10 days of castration while the concentration of estradiol cytosol receptors decreased from 225 to 16 fmoles/mg of protein. Three to five days after in vivo administration of estradiol (2 mug daily) or prolactin (1 mg daily) the concentration of estrogen receptors was increased in spayed rats. In biopsy experiments, prolactin, but not estradiol, was shown to increase the estrogen receptor concentration when endogenous prolactin release was blocked by CB 154. Prolactin did not modify the intracellular distribution of the estrogen receptor or its binding affinity for estrogen. The uterine estrogen receptor sites were not modified by prolactin under the same conditions. We, therefore, suggest that in mammary tumors prolactin sensitizes the action of estrogens at the target level by increasing the concentration of their available receptor sites.
 ...
PMID:Regulation of estrogen receptors in ovarian-dependent rat mammary tumors. I. Effects of castration and prolactin. 17 71


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>