Progesterone Receptor Content Research Articles

Estradiol up-regulates estrogen receptor-alpha messenger ribonucleic acid in sheep endometrium by increasing its stability.

During the preovulatory period, estrogen up-regulates estrogen receptor-alpha (ER) gene expression in endometrium in female mammals of all species examined. The purpose of this study was to determine directly whether estradiol up-regulates ER mRNA by increasing the stability of the message. Endometrial tissue was collected from ovariectomized ewes 18 h after the ewes were injected with 50 microg estradiol. Previous work indicated rapid accumulation of ER mRNA at this time. Estradiol increased uterine weights (to 157 +/- 15%) as well as steady-state concentrations of ER (to 309 +/- 37%), progesterone receptor (PR; to 165 +/- 19%), and glyceraldehyde 3-phosphate dehydrogenase (GAPDH; to 374 +/- 32%) mRNAs in endometrium, compared to control levels of 100%. The effects of estradiol on ER mRNA stability in endometrium were measured in explants cultured with the transcription inhibitor 5, 6-dichloro-1-beta-D-ribofuranosylbenzimidazole, as well as by labeling RNA in vivo with 4-thiouridine. Both assays indicated that estradiol enhanced ER mRNA stability (half-life increased from 9 h to >/= 24 h). The estradiol effect was specific, because the stabilities of PR, GAPDH, and c-fos mRNAs were unaffected by treatment. Thus, estradiol up-regulates steady-state concentrations of ER mRNA in endometrium by a novel posttranscriptional mechanism.

Flow cytometry of porcine ovarian cells: Antiprogestins play an important role in progesterone receptor upregulation

To investigate the mechanism of antiprogestins in the regulation of ovarian function, a dual-chamber culture system was prepared with the amnion membrane of human placenta. Isolated porcine granulosa and thecal cells were grown on both sides of the amnion and co-cultured with or without RU486 and ZK98,734. After 48 h incubation, the progesterone receptor (PR) and estrogen receptor (ER) of both cells were detected by flow cytometry. Progesterone and estradiol concentrations in the media were measured by radioimmunoassay. The results showed that antiprogestins increased PR contents in both cells; no significant change was found for ER. At the same time the progesterone and estradiol production by granulosa cells was inhibited; the progesterone production by thecal cells was reduced also. These data suggest that progesterone regulates progesterone synthesis. This autocrine/paracrine action may be the approach through which progesterone controls PR upregulation. It could be one mechanism for the inhibition of follicle development and steroidogenic function by antiprogestins.

Mapping loss of heterozygosity at chromosome 13q: loss at 13q12-q13 is associated with breast tumour progression and poor prognosis

Several chromosome regions exhibit loss of heterozygosity (LOH) in human breast carcinoma and are thought to harbour tumour suppressor genes (TSG). At chromosome 13q, two TSGs have been identified, RB1 at 13q14 and BRCA2 at 13q12-q13. In this study, 139 sporadic breast tumours were analysed with 18 polymorphic microsatellite markers for detailed mapping of LOH at chromosome 13q and evaluation of an association with known progression factors. LOH with at least one marker was observed in 71 (51%) of the tumours analysed. The deletion mapping indicated three LOH target regions, 13q12-q13, 13q14 and 13q31-q34. LOH at chromosome 13q12-q13 was associated with low progesterone receptor content, a high S phase fraction and aneuploidy. Multivariate analysis adjusting for lymph node involvement and S phase fraction showed that patients with tumours exhibiting LOH at 13q12-q13 have a 3–4-fold increased risk of recurrence and death compared with other patients. Our results suggest there are at least three separate LOH target regions at chromosome 13q and inactivation of one or more genes at chromosome 13q12-q13 results in poor prognosis for breast cancer patients.

Correlation between the growth of uterine leiomyomata and estrogen and progesterone receptor content in needle biopsy specimens

Objective: To examine the relationship between estrogen receptor (ER) and progesterone receptor (PR) content in needle biopsy specimens and the growth of uterine leiomyomata after biopsy. Design: Prospective clinical study. Setting: University teaching hospital. Patient(s): Thirty-one women with uterine leiomyomata and a normal menstrual cycle. Intervention(s): Transcervical needle biopsy of uterine leiomyomata. Main Outcome Measure(s): The relationships between histologic features (smooth muscle content, immunohistochemical expression of ER and PR) and the percent increase over a 12-month observation period in the volume of the largest myoma nodule measured by magnetic resonance imaging were analyzed. Result(s): Both the density and intensity of immunohistochemical staining of PRs in uterine leiomyoma tissue showed significant positive correlation with leiomyoma growth. Conclusion(s): The growth of uterine leiomyomata can be determined by histologic and immunohistochemical analysis of needle biopsy specimens from uterine leiomyomata.

Prognostic impact of morphometric nuclear grade of endometrial carcinoma

BACKGROUND The identification of high risk patients with endometrial carcinoma is considered essential for individualized therapy to improve prognosis and avoid overtreatment. The goal of the current study was to investigate the prognostic value of nuclear morphometry, particularly for patients with localized endometrial carcinoma. METHODS In a prospective study including 115 patients primarily treated for endometrial carcinoma at Haukeland University Hospital in Bergen, Norway between 1981-1990, data regarding clinical variables, histologic type, histologic grade, DNA index, estrogen and progesterone receptor concentration and nuclear morphometry were collected. The median follow-up period for the survivors was 9 years (range, 5-15 years). RESULTS International Federation of Gynecology and Obstetrics (FIGO) stage, histologic type, histologic grade (World Health Organization), DNA index, progesterone receptor concentration, mean nuclear area, greatest and smallest nuclear diameter, nuclear perimeter, and standard deviation to mean nuclear area all influenced survival significantly in univariate analyses. In multivariate analyses, FIGO stage and morphometrically determined mean nuclear size were identified as independent prognostic factors, whereas histologic grade had borderline significance. Histologic type, DNA index, progesterone receptor concentration, and standard deviation of mean nuclear area were not significantly associated with prognosis. The nuclear perimeter was identified as the most powerful prognostic morphometric factor, and in a separate multivariate analysis that included patients with localized disease only, it was also an independent prognostic factor. This also was the case for the subgroup of patients with endometrioid carcinoma, adenoacanthoma, or adenosquamous carcinoma. CONCLUSIONS Morphometric nuclear grade was a stronger prognostic factor than subjective histologic grade, histologic type, DNA index, and hormone receptor concentration in endometrial carcinoma patients, including those patients with localized disease. Cancer 1998;83:956-964. © 1998 American Cancer Society.

Prognostic impact of morphometric nuclear grade of endometrial carcinoma

The identification of high risk patients with endometrial carcinoma is considered essential for individualized therapy to improve prognosis and avoid overtreatment. The goal of the current study was to investigate the prognostic value of nuclear morphometry, particularly for patients with localized endometrial carcinoma. In a prospective study including 115 patients primarily treated for endometrial carcinoma at Haukeland University Hospital in Bergen, Norway between 1981-1990, data regarding clinical variables, histologic type, histologic grade, DNA index, estrogen and progesterone receptor concentration and nuclear morphometry were collected. The median follow-up period for the survivors was 9 years (range, 5-15 years). International Federation of Gynecology and Obstetrics (FIGO) stage, histologic type, histologic grade (World Health Organization), DNA index, progesterone receptor concentration, mean nuclear area, greatest and smallest nuclear diameter, nuclear perimeter, and standard deviation to mean nuclear area all influenced survival significantly in univariate analyses. In multivariate analyses, FIGO stage and morphometrically determined mean nuclear size were identified as independent prognostic factors, whereas histologic grade had borderline significance. Histologic type, DNA index, progesterone receptor concentration, and standard deviation of mean nuclear area were not significantly associated with prognosis. The nuclear perimeter was identified as the most powerful prognostic morphometric factor, and in a separate multivariate analysis that included patients with localized disease only, it was also an independent prognostic factor. This also was the case for the subgroup of patients with endometrioid carcinoma, adenoacanthoma, or adenosquamous carcinoma. Morphometric nuclear grade was a stronger prognostic factor than subjective histologic grade, histologic type, DNA index, and hormone receptor concentration in endometrial carcinoma patients, including those patients with localized disease.

Endometrial oestrogen and progesterone receptors and their relationship to sonographic appearance of the endometrium.

The rapid development of ultrasonographic equipment now permits instantaneous assessment of follicles and endometrium. The sonographic appearance of the endometrium has been discussed in relation to in-vitro fertilization (IVF) cycles. However, a generally agreed view of the relationship of the sonographic appearance to fecundity in IVF cycles has not emerged. We have studied the relationship between steroid receptors and the sonographic appearance of the preovulatory endometrium in natural cycles and ovulation induction cycles. Preovulatory endometrial thickness was not found to be indicative of fecundity, although a preovulatory endometrial thickness of <9 mm related to an elevated miscarriage rate. The preovulatory endometrial echo pattern did not predict fecundity. No relationships were found among endometrial appearance, endometrial steroid receptors and steroid hormone concentrations in serum. Oestrogen or progesterone receptor concentrations were not related to endometrial thickness or to concentrations of serum oestradiol, the only significant correlation being found between the endometrial concentrations of oestrogen and progesterone receptors. The ratio of progesterone:oestrogen receptor concentration was somewhat less in echo pattern B (not triple line) endometrium compared with pattern A (triple line) endometrium. Oestrogen and progesterone receptor concentrations appeared stable on gonadotrophin induction, though fewer numbers were found during clomiphene cycles than in natural cycles. With regard to the distribution of receptor concentration between clomiphene and natural cycles, most women using clomiphene had very low oestrogen receptor populations. Pregnancy rates were low, in spite of high ovulatory rates during clomiphene treatment and were mainly related to low oestrogen receptor concentrations in preovulatory endometrium.

Low biologic aggressiveness in breast cancer in women using hormone replacement therapy.

Hormone replacement therapy (HRT) has been associated with an increased risk for breast cancer. Cancers in women who use HRT are often less advanced, and lower mortality has been reported in those who use HRT than in nonusers. We sought to explain this by a comparison of indicators of tumor aggressiveness in patients who received HRT with those in patients who did not. A population-based cohort of 477 postmenopausal women with breast cancer were interviewed for the use, type, and duration of HRT. Clinical variables and indicators of tumor aggressiveness (histologic grade, hormone receptors, DNA ploidy, S-phase fraction, and c-erbB-2 oncoprotein overexpression) were analyzed. Breast tumors from HRT users were smaller (odds ratio, 0.47; P=.005), had better histologic differentiation (P=.04), and had a lower proliferation rate (S-phase fraction, P=.009) than tumors from nonusers. These differences persisted after adjustments for age and method of diagnosis (mammography screening v self-referral) by multiple logistic regression. No significant differences were observed in the estrogen (ER) or progesterone receptor content, c-erbB-2 oncogene overexpression, or axillary node involvement. A subgroup analysis showed that the tumor proliferation rates among HRT users were significantly lower only if HRT had been used at the time of diagnosis (P=.001). The type of HRT (estrogen v combination of estrogen and progesterone) was not associated with any clinical parameter or tumor phenotype. The association of HRT with lower proliferation rate and smaller tumor size was exclusively caused by ER-positive tumors (P=.0001 and P=.0035 v P > .1, respectively). The results indicate that breast cancer in women who receive HRT is biologically less aggressive than those without previous HRT. The lower cell-proliferation rate and smaller tumor size found in ER-positive tumors from current HRT users suggest a direct ER-mediated growth inhibitory effect of HRT on established breast tumors. This may at least partly explain why breast cancer in HRT users has a more favorable clinical course.

Study on relationship between ovulation inducing effect of drug-acupuncture and endometrial contents of estradiol receptor and progesterone receptor

To study the effect of Chinese herbal medicine for replenishing Kidney combined with acupuncture in treating anovulation and infertility, and the relationship between its ovulation inducing effect and endometrial contents of estradiol receptor (ER) and progesterone receptor (PR). Twenty-nine cases were treated with replenishing Kidney drugs combined with acupuncture for 1-3 months. Patients' ER and PR were measured by immunohistochemical method. And patients were classified according to PR content into PR positive group and mild PR positive group. Fifteen cases of PR positive group, completed treatment for 45 cycles, among them, 40 cycles showed ovulation, the ovulation rate being 88.89%. Ten in 14 cases, who complicated with infertility, became pregnant, the pregnant rate being 71.43%. While in 11 cases of PR mild positive group, 9 complicated with infertility, completed treatment for 33 cycle, 10 cycles showed ovulation (30.30%), and pregnant rate 22.22% (2/9). The difference between the two groups was significant (P < 0.01). The replenishing Kidney drugs combined with acupuncture treatment could result a good effect in treating infertility due to anovulation, especially on those with high endometrial PR content.

Enzyme-linked immunoabsorbent assay-detected p53 protein accumulation: a prognostic factor in a large breast cancer cohort.

This study was designed to evaluate whether patients with an unfavorable breast cancer prognosis could be identified by p53 protein overexpression detected by a quantitative enzyme-linked immunoabsorbent assay (ELISA). Extracts from 998 breast carcinomas were assayed for p53 protein by an ELISA that used both DO-1 monoclonal and CM-1 polyclonal antibodies. Relative risks (RRs) for cancer relapse and death after 6 years of follow-up for patients with p53-positive tumors based on different dichotomization criteria were determined by multivariate Cox regression, adjusted for patient age, tumor size, S-phase fraction, estrogen (ER) and progesterone (PR) receptor concentrations, DNA ploidy, and lymph node metastases. Disease-free (DFS) and overall (OS) survival probabilities of p53-positive and p53-negative groups, using a median cutoff, were also estimated by the Kaplan-Meier method and the log-rank test. These analyses were performed for all patients and for subgroups defined by ER status, node status, and primary postoperative treatment. Univariate analysis showed that p53 concentrations that exceeded the median indicated significantly increased risks for relapse (P < .01) and death (P = .02). Multivariate analyses confirmed these observations (RR = 1.40; P = .02 for DFS and RR = 1.50; P < .01 for OS) and showed trends for increasing risks for relapse (P = .02) and death (P = .06) when p53 was considered as a four-level categoric variable, and identified p53 positivity as a significant predictor of outcome in node-positive patients (RR = 1.67; P < .01 and RR = 2.10; P < .01 for DFS and OS, respectively), ER-positive patients (RR = 1.45; P = .02 and RR = 1.50; P = .01 for DFS and OS, respectively), and in patients treated with chemotherapy (RR = 1.73; P = .04 for relapse and RR = 2.04; P = .03 for death). Assessment of p53 overexpression by ELISA, easily incorporated into the routine biochemical work-up of breast tumors, may be an independent predictor of reduced survival of breast cancer patients.

Impact of chronic treatment of ewes with estradiol-17beta or progesterone on oxytocin receptor gene transcription and ovarian oxytocin secretion.

Three experiments were conducted, the objectives of which were to 1) examine the effects of exogenous estradiol (E2) and progesterone (P4) on uterine concentrations of oxytocin receptors (OTR) and OTR mRNA, as well as the effect of exogenous P4 on progesterone receptors (PR) during the late luteal phase of the cycle, and 2) ascertain whether chronic E2 treatment of ewes during the cycle would alter prostaglandin F2alpha (PGF2alpha)-induced secretion of luteal oxytocin (OT). In experiment 1, 15 ewes were assigned to a control (n = 5; 2 ml corn oil [CO] s.c. on Days 4-14 of the estrous cycle) and two treatment groups (n = 5 each) receiving either 250 microg E2 s.c. (Days 4-14) or 10 mg P4 s.c. (CO on Days 4-10 and P4 on Days 11-14). Endometria and corpora lutea were removed on Day 15 of the cycle. Mean luteal weights were greater in treated than in control ewes (p < 0.05). Endometrial concentrations of OTR and OTR mRNA were significantly greater in control than in E2- or P4-treated ewes. In experiment 2, five ewes each were treated s.c. with CO or 10 mg P4 on Days 11-14 of the cycle; endometria were then removed on Day 15 for PR assay. Endometrial concentration of PR did not differ between groups. Experiment 3 consisted of 20 ewes assigned to four groups in a 2 x 2 factorial arrangement. Treatment consisted of two dosages of E2 (0 or 250 microg/day) in 2 ml CO and two dosages of PGF2alpha analogue (0 or 125 microg Estrumate). All ewes were injected s.c. with E2 or CO for 11 days as described for experiment 1. On Day 15, all ewes received an i.v. injection of PGF2alpha or saline (Time 0); then jugular blood was collected at frequent intervals for analysis of serum concentrations of OT. PGF2alpha induced a release of OT in control and E2-treated ewes (p < 0.05) compared to the value in saline-treated ewes. Collectively, these data suggest that in cycling ewes, exposure of the uterus to increased concentrations of E2 or P4 causes down-regulation of OTR as a consequence of suppression of the OTR gene. Chronic E2 treatment of ewes during the cycle does not act directly on the ovary to alter the stores of luteal OT.

MULTIGENERATIONAL STUDY OF THE EFFECTS OF CONSUMPTION OF PCB-CONTAMINATED CARP FROM SAGINAW BAY, LAKE HURON, ON MINK. 3. ESTROGEN RECEPTOR AND PROGESTERONE RECEPTOR CONCENTRATIONS, AND POTENTIAL CORRELATION WITH DIETARY PCB CONSUMPTION

Mink (Mustela vison) were fed diets containing ocean fish (control diet, 0.0 ppm polychlorinated biphenyls, PCBs) or Saginaw Bay carp to provide 0.25, 0.5, or 1.0 ppm PCBs to examine the effect of PCBs on homeostasis of binding sites for ovarian steroid hormones. Ranch-raised mink fed Great Lakes fish contaminated with PCBs, or treated with PCBs directly, have demonstrated reproductive impairment including anovulation, fetal resorption, delayed ovulation, increased gestation, and decreased litter size. Previous studies have demonstrated that estrogen and progesterone levels are unaltered in mink treated with PCBs, suggesting that the effect of PCBs on reproduction is not medi ated through alterations in hormone homeostasis. In vitro studies have demonstrated that the most likely means by which PCBs exert antiestrogenic ability is through a downregulation of the estrogen receptor in normally estrogen-responsive tissues such as liver and uterus. Hepatic and uterine estrogen binding site concentrations were measured in female mink consuming diets containing PCBs for up to 18 mo at up to 1 ppm. Hepatic estrogen binding site concentrations generally decreased with increasing dietary PCB concentrations. Uterine estrogen binding site concentration did not decrease in these animals. Uterine progesterone receptor concentration also did not change with increasing PCB consumption. In total, the response of hepatic and uterine estrogen and uterine progesterone binding sites in mink fed diets containing Saginaw Bay carp suggests that concentrations of PCBs available to uterine tissue may not have been sufficient to decrease uterine estrogen receptor, despite their effect on hepatic estrogen receptor.

Stromal IGF-II messenger RNA in breast cancer: relationship with progesterone receptor expressed by malignant epithelial cells.

In breast cancer, insulin-like growth factor II (IGF-II) is stromal in origin and is considered an important regulator of tumour epithelium growth. The presence of progesterone receptor (PR) is expression of an intact oestrogen regulatory pathway of breast malignant epithelial cells and represents a parameter of cell differentiation in breast cancer. In this study we have examined the relationship between IGF-II mRNA expression and ER, PR content in 75 breast cancer. Formalin-fixed paraffin-embedded tissue sections were used to preserve histological details. IGF-II mRNA was evaluated by in situ hybridisation method and ER, PR by immunohistochemistry. IGF-II mRNA was scored semi-quantitatively: 2.6% breast tumour specimen expressed no IGF-II mRNA, 46.7% had low levels of expression (IGF-II-) and 50.7% had moderate or high IGF-II mRNA content (IGF-II+). IGF-II mRNA was found in the stroma fibroblasts surrounding malignant lesions and no signal was detected in malignant epithelial cells. In contrast, ER and PR were expressed only by neoplastic epithelial cells and no immunoreactivity was found in the stroma: 50/75 (66.6%) breast cancer specimens were positive for ER (ER+) and 35 (46.6%) for PR (PR+). Both, IGF-II mRNA and PR were directly correlated with the stromal proliferation (p < 0.05 and p < 0.001, respectively). No relationship was found between IGF-II RNA and ER. In contrast 24/35 (73.5%) PR breast cancer tissues were IGF-II+ (p < 0.01) and a strong correlation was found between epithelial PR immunostaining and stromal IGF-II mRNA content (p < 0.003). Our data indicate that in breast cancer IGF-II mRNA is generally expressed by stromal cells and ER and PR by epithelial cancer cells, and that IGF-II mRNA expression is strongly related with both percentage and staining intensity of PR+ epithelial cancer cells. These data support the hypothesis that IGF-II produced by the fibroblasts may exert a paracrin effect on malignant epithelium regulating its differentiation.

Oestradiol up-regulates oestrogen receptor, cyclophilin, and glyceraldehyde phosphate dehydrogenase mRNA concentrations in endometrium, but down-regulates them in liver

Oestradiol regulates reproductive physiology and cardiovascular health in women. In the endometrium of ovariectomized ewes, previous work demonstrated that a single dose of oestradiol (50 μg) up-regulates oestrogen receptor- α (ER) and progesterone receptor (PR) gene expression within 24 h. Here we compared responses to different doses of oestradiol and different dosing regimens in two diverse tissues: endometrium and liver. ER, c-fos, cyclophilin and glyceraldehyde phosphate dehydrogenase (GAPDH) mRNA concentrations were analyzed on replicate RNA slot blots in both tissues, while PR and apolipoprotein AI (apo AI) mRNA concentrations were only analyzed in endometrium or liver, respectively. Along with ER mRNA, oestradiol strongly up-regulated GAPDH and cyclophilin mRNA concentrations in endometrium. In liver, however, oestradiol down-regulated them, along with apo AI mRNA. Responses to different doses and dose regimens, including repeated 50 μg doses, were similar to those evoked by a single 50 μg dose of oestradiol. Thus, oestradiol appears to have all-or-none effects which include up-regulation of ER, cyclophilin and GAPDH gene expression in endometrium and down-regulation of ER, apo AI, cyclophilin and GAPDH gene expression in liver. These results illustrate the sharp contrast between two mammalian tissues in their responses to physiological levels of oestradiol.

Effects on Mouse Uterus of Three Antitumoral Drugs Acting upon Estrogen and Progesterone Receptors Directly and Through Other Transduction Pathways

Three antitumoral drugs, tamoxifen (Tam), medroxyprogesterone acetate (MPA), and 8-Cl-cyclicAMP (8Cl), were administered separately and in combination to normal adult mice in order to record their effects on uterus weight, on estrous cycle, and on two estrogen receptor (ER) and progesterone receptor (PgR) parameters, namely content and nucleo-cytoplasm distribution. Tam decreased uterus weight (49%) and total ER content (118 ± 6 vs 328 ± 20 fmol/mg protein in controls) but increased total PgR (1183 ± 230 vs 743 ± 52 fmol/mg protein in controls) and nuclear retention of ER and PgR. MPA down-regulated PgR content and increased uterus weight (36%), but failed to modify ER and PgR nuclear retention. The only parameter changed by 8Cl was nucleo-cytoplasm PgR distribution. Tam + MPA association produced the same results as Tam alone for ER and PgR nuclear retention, but receptor content was not significantly different from that of controls. Both drugs, administered separately, had opposite effects on PgR content; when both were acting concurrently, an algebraic addition of effects was observed, as if both transcription circuits were triggered independently. Remaining Tam effects, not modified by a combination with MPA, indicated the predominance of Tam on the corresponding parameters. When Tam and 8Cl were administered together, 8Cl counteracted the effect of Tam only on PgR content. When associated with MPA, 8Cl changed the effects of MPA on ER and PgR nuclear retention, whereas on receptor content, only that of ER was increased (502 ± 47 vs 328 ± 20 fmol/mg protein in controls). These crossed effects indicate that interrelations between different transduction pathways can affect certain functional circuits while sparing others. The possibility of acting pharmacologically upon different transcription pathways represents a novel approach to modify drug effects directed to specific transduction targets through cross-talk between their components.

Estrogen and Progesterone Receptors of Adenomyosis in Postmenopausal Breast Cancer Patients Treated with Tamoxifen

Adenomyosis is an ectopic endometrial tissue located in the myometrium. It has been reported to develop at a higher rate among postmenopausal breast cancer patients on tamoxifen (TAM) treatment than in untreated patients. It has also been reported to be stimulated by estrogen. Assessing receptor levels in adenomyotic tissue may indicate the adenomyotic cell’s potential to interact with TAM. In the present study the estrogen receptor (ER) and progesterone receptor (PR) were analyzed by an immunohistochemical technique in adenomyotic and the corresponding endometrial tissues of 14 postmenopausal breast cancer patients treated with TAM and in 15 healthy postmenopausal patients who served as controls. All TAM-treated patients had normal postmenopausal serum estradiol levels. Overall the ER and PR contents in adenomyotic tissue (42.9 and 71.4%) and in the endometriotic tissue (64.3 and 78.6%) obtained from the study patients were similar to those obtained from the control group (adenomyosis, ER and PR = 46.7 and 86.7%; endometrium, ER and PR = 40 and 73.3%; p = NS). In the study group, the ER content was lower in the adenomyotic (42.9%) than in the endometriotic tissue (64.3%). No correlation was found between the duration of TAM therapy, the TAM dosage level or the ER or PR content in the adenomyotic or endometrial tissues. The finding of a relatively low ER content in the adenomyotic tissue than in the endometriotic tissue in postmenopausal TAM-treated patients without endogenous estrogens, similar to that observed in healthy premenopausal women, may be attributed to the estrogen-like effect of TAM.

Influence of gestation on uterine endometrial steroid receptor concentrations in the African elephant, Loxodonta africana.

The modulatory effects of gestational age and circulating concentrations of progesterone, 5alpha-pregnane-3,20-dione, and estradiol-17beta on the uterine sex steroid hormone receptor levels of the African elephant were investigated. Uterine tissue biopsies and blood samples were obtained from animals culled in the Kruger National Park. Estrogen and progesterone receptor concentrations were determined in uterine biopsies from subadult, lactating, early-, mid-, and late-pregnant elephants, by equilibrium binding assays. Circulating estradiol-17beta and progesterone concentrations were measured by means of RIAs, while plasma concentrations of 5alpha-pregnane-3,20-dione were determined with an amplified ELISA. Significant inverse correlations of the concentrations of estrogen and progesterone receptors with the gestational stage of the elephants were observed. Pregnant uterine horns of individual animals contained lower levels of estrogen and progesterone receptors than the nonpregnant horns of the same animals. A strong positive correlation existed between uterine estrogen and progesterone receptors levels. Circulating concentrations of 5alpha-pregnane-3,20-dione and progesterone decreased with an increase in the concentrations of progesterone receptors as well as with fetal age. We conclude that the progesterone receptor concentrations are down-regulated with progressing gestation in the African elephant. This down-regulation appears to be linked to an increase in circulatory 5alpha-pregnane-3,20-dione concentration in the plasma of pregnant animals.

Sensitivity of a Tier I Screening Battery Compared to an in Utero Exposure for Detecting the Estrogen Receptor Agonist 17β-Estradiol

A Tier I screening battery for detecting endocrine active compounds (EACs) has been evaluated for its ability to identify 17β-estradiol, a pure estrogen receptor agonist. In addition, the responses obtained with the Tier I battery were compared to the responses obtained from F1 generation rats from a 90-day/one-generation reproduction study with 17β-estradiol in order to characterize the sensitivity of the Tier I battery against the sensitivity of an in utero exposure for detecting EACs. The Tier I battery incorporates two short-term in vivo tests (5-day ovariectomized female battery; 15-day Intact male battery) and an in vitro yeast transactivation system (YTS) for identifying compounds that alter endocrine homeostasis. The Tier I female battery consists of traditional uterotrophic endpoints coupled with biochemical and hormonal endpoints. It is designed to identify compounds that are estrogenic/antiestrogenic or modulate dopamine levels. The Tier I male battery consists of organ weights coupled with microscopic evaluations and a comprehensive hormonal assessment It is designed to identify compounds that have the potential to act as agonists or antagonists to the estrogen, androgen, progesterone, or dopamine receptor; steroid biosynthesis inhibitors (aromatase, 5 α-reductase, and testosterone biosynthesis); or compounds that alter thyroid function. The YTS is designed to identify compounds that bind to steroid hormone receptors (estrogen, androgen, and progesterone) and activate gene transcription. The profile generated for 17β-estradiol was characteristic of the responses expected with a pure estrogen receptor agonist. In the female battery, responses to 17β-estradiol included increases in uterine fluid imbibition, uterine weight, estrus conversion, uterine stromal cell proliferation, uterine epithelial cell height, uterine progesterone receptor content, serum prolactin and estradiol levels, and decreases in uterine estrogen receptor content and follicle stimulating hormone and luteinizing hormone levels. In the male battery, responses to 17β-estradiol included decreases in absolute testis and epididymi-des weights, decreases in relative weights for androgen-dependent tissues (prostate, seminal vesicles, and accessory sex gland unit), hormonal alterations (decreased serum testosterone, dihydrotest-osterone, and LH and increased serum prolactin levels), and microscopic alterations of the testis and epididymides. In the YTS for the estrogen receptor, 17β-estradiol had an EC50, value of 7.2 × 10−9 M, while DHT and progesterone had little cross-activation. The androgen and progesterone receptor systems were less selective in that 17β-estradiol activated these systems within 3 orders of magnitude of the primary ligand. In the 90-day/one-generation reproduction study, responses to dietary administration of 17β-estradiol included alterations in organ weights, developmental landmarks, and hormonal levels. Comparison of the responses obtained with our Tier I battery and an in utero exposure demonstrates that the Tier I screening battery is as sensitive as an in utero exposure for detecting 17β-estradiol-induced alterations in hormonal homeostasis.

Prognostic value of loss of heterozygosity at BRCA2 in human breast carcinoma.

To confirm several recent studies pointing to loss of heterozygosity (LOH) at BRCA2 as a prognostic factor in sporadic breast cancer, we examined this genetic alteration in a large series of human primary breast tumours for which long-term patient outcomes were known. LOH at BRCA2 correlated only with low oestrogen and progesterone receptor content. Univariate analysis of metastasis-free survival and overall survival (log-rank test) showed no link with BRCA2 status (P = 0.34, P = 0.29 respectively). LOH at BRCA2 does not therefore appear to be a major prognostic marker in sporadic breast cancer.

Retinoic acid receptors alpha, beta and gamma, and cellular retinol binding protein-I expression in breast fibrocystic disease and cancer.

Retinoids seem to act as agents of chemoprevention and differentiation in breast diseases. Their action is mediated by nuclear receptors, retinoic acid receptors (RAR alpha, RAR beta, RAR gamma) and retinoid X receptors (RXR alpha, RXR beta, RXR gamma) and modulated by cellular retinol binding proteins (CRBP). There are few published data on CRBP expression. In this study, we evaluated the expression of RAR alpha, beta and gamma and CRBP type I (CRBP-I) gene expression in fibrocystic disease (FD) and in breast cancer (BC), studying 14 FD and 20 BC surgical samples by reverse transcription (RT)-PCR. We also evaluated mRNA concentrations in cancer samples by a semiquantitative PCR method, co-amplifying RAR alpha, RAR beta and CRBP-I genes with an unrelated gene, glyceraldehyde 3-phosphate dehydrogenase (GAPDH), as internal control. All benign and malignant breat tissues expressed RAR alpha, beta and gamma, and CRBP-I mRNAs. A greater concentration of RAR beta mRNA was detected in cancer tissues with lower oestrogen and progesterone receptor concentrations, whereas RAR alpha was detected in variable concentrations that were not related to those of steroid receptors. The CRBP-I concentration was similar in all samples studied. We demonstrated that all three RARs and CRBP-I transcripts are expressed in FD, and that RAR beta, RAR gamma and CRBP-I mRNAs also are present in BC tissues. This indicates that both malignant and benign breast tissues may be target for retinoids, justifying the use of natural and synthetic vitamin A derivatives in the chemoprevention of breast disease.