Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0476089 (endometrial cancer)
 11,379 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In 22 patients with endometrial carcinoma, Stage I-III (mean age 57.8 years) with obesity, initial and reactive hyperinsulinemia (during glucose load) was revealed. Significant correlations between values of "peak" and field-square of the insulin secretion curve and cytoplasmatic receptors to Estradiol and Progesterone in the tumor were found. In a group of the patients with high values of reactive hyperinsulinemia significantly larger amounts of steroid hormone receptors in the tumor were determined as compared to the group of the patients who had low insulinemia values. On considering these data a possible conclusion was reached as to the modifying influence of hyperinsulinemia on sensitivity of endometrial carcinoma to hormone receptor synthesis in the tumor by insulin.
 ...
PMID:Hyperinsulinemia as a factor modifying sensitivity of endometrial carcinoma to hormonal influences. 850 Apr 94

A high percentage of endometrial carcinomas contain oestrogen and progesterone receptors. For endocrine therapy of recurrent endometrial carcinoma, only high-dose progestins are in clinical use. As, therefore, the development of new endocrine treatment strategies is of great interest, suitable animal models for this tumour are essential. Up to now, only human tumour xenografts transplanted in immune-deficient nude mice, but no syngeneic in vivo tumour models, have been available. In the present article we describe the hormone sensitivity of the EnDA endometrial adenocarcinoma of the DA/Han rat growing as s.c. implants in DA/Han rats and athymic nude mice in serial passage. In both species, the tumour expresses oestrogen, but no progesterone receptors. Transplanted in DA/Han rats or nude mice, ovariectomy reduced tumour weight by 64% and 46% respectively. In both species substitution of ovariectomized animals with oestradiol restored tumour weights to intact control levels. Oestradiol substitution of intact animals did not further enhance tumour growth. The growth of the primary tumour was inhibited by medroxyprogesterone acetate (MPA) at a dose of 100 mg/kg by 67% and by tamoxifen at a dose of 20 mg/kg by 38%. Lung metastases were regularly seen in both species, although to a lesser extent in nude mice than in DA/Han rats. Tamoxifen treatment did not alter the number of lung metastases, whereas MPA or ovariectomy produced a significant reduction in the number of lung metastases. The EnDA endometrial carcinoma of the DA/Han rat with respect to its oestrogen sensitivity, oestrogen receptor expression, morphology and metastatic growth, grossly resembles a typical endometrial adenocarcinoma and can therefore be regarded as a useful in vivo experimental model for the evaluation of new endocrine treatment strategies.
 ...
PMID:The EnDA endometrial adenocarcinoma: an oestrogen-sensitive, metastasizing, in vivo tumour model of the rat. 850 35

The failure of follicular development that characterizes the menopause leads to a marked reduction in serum levels of estradiol and progesterone. As a result, the majority of women develop symptoms, including hot flushes, sleep disturbance, and vaginal dryness. Long-term consequences of ovarian insufficiency include genital atrophy, osteoporosis, and increased rates of myocardial infarction. Estradiol replacement (ERT) has proved effective in treating and preventing these problems. ERT has, however, led to increased risk of endometrial carcinoma. Consequently, treatment regimens now include progestins (HRT) to protect women who have a uterus. Progestins act by down-regulation of estradiol receptor activity, which is an advantage for preventing endometrial hyperstimulation, but a potential disadvantage when beneficial effects of estradiol are opposed. Current menopause health care includes assessment, treatment, and follow-up. Signs and symptoms of estradiol deficiency are evaluated during initial history-taking and physical examination. The MENSI (Menopause Symptom Index) has proved an efficient questionnaire for both initial assessment and monitoring of treatment effects. Vaginal cell maturation index (M.I.) can be helpful in determining need for hormonal treatment and for assessing response to treatment. A "therapeutic range" for ERT can be achieved with the availability of a variety of hormone preparations administered in different ways (oral, transdermal, skin gel, implants, etc.), thus avoiding the problems of both inadequate and excessive hormonal doses. This paper will describe a structured approach to the delivery of health care in the menopause.
 ...
PMID:Hormone replacement therapy in the menopause. 916 Feb 17

The endometrium, as a target of estrogens and progestins, possesses the respective receptor proteins. These receptors belong to the superfamily of nuclear receptors, having important functional domains required for steroid ligand binding, for dimer formation, for interaction with HREs of DNA, for transcription modulation, for association with other proteins, for intracellular trafficking, and other activities. The mechanism of action of the steroid hormones involves modulation of gene activity through interaction of the hormone-receptor complex with HREs and with other nuclear proteins, but also encompasses nongenomic effects, which accounts for the rapid effects of the steroids on cellular functions. Antihormones-antiestrogen and antiprogestins-compete with their respective hormones for binding sites on the receptor molecules. Some antihormones are partial agonists. The molecular mechanisms underlying the dual behavior of antihormones is under consideration. The concentration of ER and PR in different physiological and pathophysiological states, such as the menstrual cycle, pregnancy, and endometrial cancer, has been determined by biochemical and immuno(cyto)chemical methods. The levels of estrogens and progestins are important regulators of ER and PR gene expression. Estradiol acts as a cell mitogen, inducing key genes involved in replication, and its tumor promoter effect is discussed in this sense, whereas progesterone has reverse effects when compared to estradiol and acts as a differentiation factor. The cross-talk between the endocrine system, growth factors, and neurotransmitters can take place both at the receptor level, involving mainly phosphorylation reactions, and at the gene level, mainly through protein-protein interactions.
 ...
PMID:Estrogen and progesterone receptors in the endometrium. 923 60

In order to test the hypothesis that integrin and uteroglobin (UG) expression in cultured endometrial cells are affected by hormone treatment, Ishikawa-CH endometrial cancer cells were cultured and exposed to oestradiol or oestradiol and progesterone regimens and assayed using immunohistochemistry. We evaluated the intensity of immunohistochemical staining for the integrin monomers alpha(v) and beta1, the dimers alpha(v)beta3 and alpha(v)beta6, and for the secretory protein uteroglobin under various experimental conditions. Cells grown in control media stained positively for the integrin monomers alpha(v) and beta1, the dimer alpha(v)beta3, and for UG. Oestradiol and sequential oestradiol/progesterone reversibly suppressed staining for the dimer alpha(v)beta3. Hormone treatment had no effect on the staining of the beta1 and alpha(v) monomers or UG. The alpha(v)beta6 dimer antibody did not stain under any experimental treatment conditions. These data indicate that expression of the integrin complex alpha(v)beta3 is reversibly suppressed by oestradiol in Ishikawa cells and that these cells may be a good model for studying hormone-driven molecular changes in endometrium.
 ...
PMID:Modulation of implantation-associated integrin expression but not uteroglobin by steroid hormones in an endometrial cell line. 926 33

To ascertain one of the biological effects of danazol and progesterone on the uterine endometrial cancer cell line, Ishikawa, we investigated the effects of these steroids on sex hormone-binding globulin (SHBG) mRNA expression by competitive reverse transcription-polymerase chain reaction-Southern blot analysis (RT-PCR-SBA). Estradiol-17beta (E2) in any concentration given did not exert any significant effect on the expression of SHBG mRNA. Danazol and progesterone significantly (P < 0.05) suppressed the expression of SHBG mRNA dose-dependently starting at a concentration of 10(-6) and 10(-8) M, respectively. Progesterone, in a low concentration (10[-10] M) with E2 (10[-8] M), significantly (P < 0.05) increased the expression of SHBG mRNA, but danazol did not. In contrast, danazol and progesterone in high concentrations (10[-6] to 10[-5] M) with E2 (10[-8] M) significantly (P < 0.05) suppressed its expression. The time course study showed the time-dependent decrease of SHBG mRNA level by danazol and progesterone (10[-6] M) with or without E2 (10[-8] M), except for a temporal increase by progesterone. These findings suggest that danazol and progesterone in a superphysiological milieu down-regulate the intracellular SHBG-related steroidal actions, and that progesterone in a physiological milieu with estrogen up-regulates it in a hormone-dependent cell line. A decrease of intracellular SHBG caused by high-dose danazol or progesterone might partly contribute to the abolition of the intracellular estrogen-dominant milieu, and be related to the inhibition of estrogen-dependent growth of some endometrial cancer cells.
 ...
PMID:Effects of danazol and progesterone on sex hormone-binding globulin mRNA expression in human endometrial cancer cell line Ishikawa. 940 86

Estradiol induces vascular endothelial growth factor (VEGF) expression in the rat uterus and this may contribute to the hyperemia and increased vascularity produced by estrogens in this target tissue. Triphenylethylene antiestrogens such as tamoxifen have mixed agonist/antagonist activity and their specific effects are tissue and gene specific. These drugs exhibit primarily antiestrogenic actions in mammary tissue and are thus used for the treatment of breast cancer. These drugs are also suggested to be inhibitors of angiogenesis. However, uterine side effects of tamoxifen are thought to stem largely from the agonist activity of the drug in this tissue. Since side effects of tamoxifen such as uterine bleeding and endometrial cancer seem likely to have an angiogenic component, we have examined the effects of this drug, its metabolite, 4-hydroxy-tamoxifen and two additional triphenylethylene antiestrogens, nafoxidine and clomiphene, on the expression of VEGF and another estrogen regulated gene, c-fos, using the rat uterus as an experimental system. All four compounds increase uterine VEGF and c-fos mRNA levels indicating that the triphenylethylene class of antiestrogens are predominantly agonists for the induction of these genes in the uterus.
 ...
PMID:Triphenylethylene antiestrogens induce uterine vascular endothelial growth factor expression via their partial estrogen agonist activity. 946 Oct 33

To elucidate potential mechanisms involved in the increased incidence of endometrial carcinomas in tamoxifen-treated patients, we examined the in-vitro effects of tamoxifen on endometrial cancer cells. The effects of tamoxifen, alone and in combination with oestradiol, on cell proliferation, plasminogen activator (PA) activity, glycogen synthase and phosphorylase activities, p53 protein concentration, and collagenase expression were assessed in two human adenocarcinoma cell lines. These lines were the oestrogen receptor-positive (Ishikawa) cells, representing a well-differentiated endometrial adenocarcinoma, and oestrogen receptor-negative (HEC-1A) cells, derived from a poorly differentiated endometrial adenocarcinoma. Tamoxifen or oestradiol alone and their combination significantly enhanced cellular proliferation of Ishikawa but not of HEC-1A cells. Both lines produced appreciable PA activity, most of which was of the urokinase type. Tamoxifen and oestradiol stimulated this activity in Ishikawa cells but not in HEC-1A cells. The effect of oestradiol was dose-dependent in a linear fashion, while tamoxifen produced a stimulation peaking at 10(-8) M and declining at higher concentrations. Tamoxifen in combination with oestradiol exhibited a synergistic effect on proliferation and on PA activity. The response of PA extended beyond the increase in proliferation, leading to higher specific activity of PA in the tamoxifen-treated cultures. In Ishikawa cells, oestradiol also increased glycogen synthase and glycogen phosphorylase activities, while tamoxifen markedly suppressed these enzymes. Oestradiol, tamoxifen, and their combination had no apparent effect on the expression of protein p53 in Ishikawa cells, or on gelatinase activity in either Ishikawa or HEC-1A cells. The present findings imply that tamoxifen produces oestrogen-agonistic effects on cell proliferation and PA activity, and oestrogen antagonistic effects on glycogen synthase and glycogen phosphorylase activities, but fails to regulate p53 and gelatinase expression. The tamoxifen-responsive systems were only observed in oestrogen-responsive adenocarcinoma cells. Thus, only certain potential oncogenic effects of tamoxifen can be simulated in vitro, and when present, these effects are enhanced in the presence of oestradiol.
 ...
PMID:Tamoxifen exerts oestrogen-agonistic effects on proliferation and plasminogen activation, but not on gelatinase activity, glycogen metabolism and p53 protein expression, in cultures of oestrogen-responsive human endometrial adenocarcinoma cells. 946 46

To understand the rationale of high-dose medroxyprogesterone acetate (MPA) in the treatment of well-differentiated uterine endometrial cancers, the effect of MPA on intracellular sex hormone-binding globulin (SHBG) mRNA expression in well-differentiated uterine endometrial cancer cell line Ishikawa was determined by competitive reverse transcription-polymerase chain reaction-Southern blot analysis. Estradiol-17beta (E2, 10(-8) mol/l) did not alter SHBG mRNA expression, but the addition of 10(-10) mol/l MPA increased it, while a high concentration of MPA (10(-6) to 10(-5) mol/l) with or without E2 suppressed it. Furthermore. a high dose (10(-6) mol/l) of chlormadinone acetate or danazol with or without E2 significantly suppressed its expression, while MPA was the most effective among the hormones tested. The effect of MPA and the other steroid hormone analogs on SHBG expression was not mediated via the progesterone receptor. These findings suggest that intracellular SHBG suppression might partly contribute to the abolition of the intracellular estrogen-dominant milieu, and may be involved as one of the mechanisms of the antitumoral effects of high-dose MPA on the development and growth of some well-differentiated endometrial cancer cells.
 ...
PMID:Effect of medroxyprogesterone acetate on sex hormone-binding globulin mRNA expression in the human endometrial cancer cell line Ishikawa. 962 72

The effect of progestins on intracellular corticosteroid-binding globulin (CBG) mRNA expression in an endometrial cancer cell line (Ishikawa) was examined in an attempt to understand the biological effects of high-dose progestins in the treatment of well-differentiated uterine endometrial cancers. Oestradiol-17 beta (E2) significantly increased CBG mRNA expression in a dose-dependent manner, while a high dose of progesterone with or without E2 suppressed it significantly. Furthermore, a high dose of progesterone or medroxyprogesterone acetate (MPA) suppressed CBG mRNA expression to a greater degree than did chlormadinone acetate or 17 alpha-hydroxyprogesterone caproate with or without E2. These findings suggest that the effects of high-dose progestins on cancer cells may be mediated via suppression of intracellular CBG.
 ...
PMID:Effects of sex steroid hormones on corticosteroid-binding globulin gene expression in human endometrial cancer cell line Ishikawa. 976 30


<< Previous 1 2 3 4 5 6 Next >>