1000 resultados para Receptors, Progesterone


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Expression of estrogen (ER) and progesterone (PR) receptors has traditionally been associated with hormone-responsive organs, such as breast, ovary, and endometrium, and carcinomas arising therefrom. More recently, examples of ''unexpected'' ER or PR expression have been reported, particularly in tumors of endocrine tissues, such as thyroid and pancreatic islet cells. We tested the hypothesis that neuroendocrine tumors of various primary and metastatic sites might also express ER or PR or both by performing a retrospective immunohistochemical study in a series of 59 formalin- or mechacarn-fixed neuroendocrine carcinomas of various sites, including lung, skin, gastrointestinal and female genital tracts, and including carcinoid and atypical carcinoid tumors, small cell carcinomas, and Merkel cell carcinomas. We employed the anti-ER monoclonal antibody 1D5 and the anti-PR monoclonal antibody PgR1A6 using standard immunohistochemical techniques after microwave-based heat-induced epitope retrieval. Two of 28 carcinoid tumors demonstrated ER positivity; six of 30 cases were positive for progesterone receptor only. In addition, PR expression was found in one of two cases of atypical carcinoid, in five of 25 cases of small cell carcinoma, and in one of two cases of Merkel cell carcinoma. None of the atypical carcinoids, small cell carcinomas, or Merkel cell carcinomas were ER positive. In most cases, the fraction of tumor cell nuclei that were positive was <50%. These studies add the spectrum of neuroendocrine tumors that can express these hormone receptors. Similar to the pattern previously described in the subsets of meningiomas and islet cell tumors, PR but not ER is detectable in most cases. These results underscore the caution that should be exercised in determining tissue origin of metastatic carcinomas based only on detection of hormone receptors by immunohistochemistry.

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Chronic ethanol intake is associated with sex hormone disturbances, and it is well known that melatonin plays a key role in regulating several reproductive processes. We report the effects of ethanol intake and melatonin treatment (at doses of 100. μg/100. g. BW/day) on sex hormones and steroid receptors in the ovaries, oviducts and uteri of ethanol-preferring rats. After 150 days of treatment, animals were euthanized, and tissue samples were harvested to evaluate androgen, estrogen, progesterone and melatonin receptor subunits (AR, ER-α and ER-β, PRA, PRB and MT1R, respectively). Melatonin decreased estradiol (E2) and increased progesterone (P4) and 6-sulfatoxymelatonin (6-STM), while an ethanol-melatonin combination reduced both P4 and E2. Ovarian AR was not influenced by either treatment, and oviduct AR was reduced after ethanol-melatonin combination. Oviduct ER-α, ER-β and uterine ER-β were down-regulated by either ethanol or melatonin. Conversely, ovarian PRA and PRB were positively regulated by ethanol and ethanol-melatonin combination, whereas PRA was down-regulated in the uterus and oviduct after ethanol consumption. MT1R was increased in ovaries and uteri of melatonin-treated rats. Ethanol and melatonin exert opposite effects on E2 and P4, and they differentially regulate the expression of sex steroid receptors in female reproductive tissues. © 2013 Elsevier Inc.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Background. Ductal carcinoma in situ (DCIS) is the most prevalent precursor to invasive breast cancer (IBC), the second leading cause of death in women in the United States. The three most important prognostic markers for IBC are Estrogen receptor (ER), Progesterone receptor (PR) and HER2/neu. The four groups (IBC) defined as (1) ER and/or PR positive and HER2/neu negative, (2) ER and/or PR positive and HER2/neu positive (3) ER and/or PR negative and HER2/neu positive and (4) negative for all three of these receptors (Triple negative). However, they have not been well studied in DCIS. This is an exploratory study with a primary objective to examine the prevalence of ER, PR, and HER2/neu in DCIS, to explore if the defined groups of IBC occur in DCIS and to consider the biological relationship between these four groups and the proliferative activity of the tumor. A secondary goal of this study is to examine the relationship between grade and proliferative activity. Methods. Using immunohistochemistry, I have measured Ki-67, ER, PR and HER2/neu positivity for a series of cases of DCIS. Results. 20 ER and/or PR positive and HER2/neu negative (50%) with average PI of 0.05, 7 ER and/or PR positive and HER2/neu positive (17.5%) with average PI of 0.14, 10 ER and/or PR negative and HER2/neu positive (25%) with average PI of 0.18, and three triple negative (7.5%) with average PI of 0.18. ER and/or PR positive and HER2/neu positive group has the highest PI (p<0.001). Further, the ER and/or PR positive and HER2/neu positive group show a linear relationship between PI and average ER/PR positivity (R=0.6). PI increases with higher grades. Conclusion. PI appears to depend upon the average fraction of positive ER/PR tumor cells, possibly with a synergistic dependence when HER2/neu is positive. If ER/PR is negative, then both HER2/neu positive and the triple negative cases appear to cluster around an average PI that is higher than the average PI in HER2/neu negative ER/PR positive negative cases. In the triple negative tumors there must be another driver of proliferation.^

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The 2.8-Å crystal structure of the complex formed by estradiol and the human estrogen receptor-α ligand binding domain (hERαLBD) is described and compared with the recently reported structure of the progesterone complex of the human progesterone receptor ligand binding domain, as well as with similar structures of steroid/nuclear receptor LBDs solved elsewhere. The hormone-bound hERαLBD forms a distinctly different and probably more physiologically important dimer interface than its progesterone counterpart. A comparison of the specificity determinants of hormone binding reveals a common structural theme of mutually supported van der Waals and hydrogen-bonded interactions involving highly conserved residues. The previously suggested mechanism by which the estrogen receptor distinguishes estradiol’s unique 3-hydroxy group from the 3-keto function of most other steroids is now described in atomic detail. Mapping of mutagenesis results points to a coactivator-binding surface that includes the region around the “signature sequence” as well as helix 12, where the ligand-dependent conformation of the activation function 2 core is similar in all previously solved steroid/nuclear receptor LBDs. A peculiar crystal packing event displaces helix 12 in the hERαLBD reported here, suggesting a higher degree of dynamic variability than expected for this critical substructure.

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Our laboratory has previously found that anti-mitogenic nuclear receptor mRNA is elevated in late stage tumours and this study was performed to scrutinize the possibility of cancer-stroma crosstalk using hormone signaling in these tissues. RNA levels in stromal tissue were examined for the estrogen α, estrogen β, androgen, progesterone and glucocorticoid nuclear receptors by a semi-quantitative PCR. Significant differences in expression between the cancer stroma and control tissue were seen, analyzing for both cancer grade and estrogen receptor status. Stroma and control tissue were significantly different for the progesterone and glucocorticoid nuclear receptors (p = 5.908 × 10−7 and 2.761 × 10−5, respectively). Glucocorticoid receptor also showed a significant increase to mRNA levels in the stroma of estrogen receptor negative tumours (p = 5.85 × 10−5). By contrast, the estrogen receptors α and β, those most closely associated with breast tissue growth, showed no significant change in mRNA (p = 0.372 and 0.655, respectively). Androgen receptor mRNA also remained unaffected (p = 0.174).

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Problem Susceptibility to Chlamydia trachomatis infection is increased by oral con- traceptives and modulated by sex hormones. We therefore sought to determine the effects of female sex hormones on the innate immune response to C. trachomatis infection. Method of study ECC-1 endometrial cells, pre-treated with oestradiol or progesterone, were infected with C. trachomatis and the host transcriptome analysed by Illumina Sentrix HumanRef-8 microarray. Primary endocervical epithe- lial cells, prepared at either the proliferative or secretory phase of the menstrual cycle, were infected with C. trachomatis and cytokine gene expression determined by quantitative RT-PCR analysis. Results Chlamydia trachomatis yield from progesterone-primed ECC-1 cells was significantly reduced compared with oestradiol-treated cells. Genes upregulated in progesterone-treated and Chlamydia-infected cells only included multiple CC and CXC chemokines, IL-17C, IL-29, IL-32, TNF-a, DEFB4B, LCN2, S100A7-9, ITGAM, NOD2, JAK1, IL-6ST, type I and II interferon receptors, numerous interferon-stimulated genes and STAT6. CXCL10, CXCL11, CX3CL1 and IL-17C, which were also upregu- lated in infected secretory-stage primary cells, and there was a trend towards higher levels of immune mediators in infected secretory-phase compared with proliferative-phase cells. Conclusion Progesterone treatment primes multiple innate immune pathways in hormone-responsive epithelial cells that could potentially increase resis- tance to chlamydial infection.

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Induction of follicle stimulating hormone receptor in the granulosa cells of intact immature rat ovary by diethylstilbesterol, an estrogen, has been studied. A single injection of 4 mg of diethylstilbesterol produced 72 h later a 3-fold increase in follicle stimulating hormone receptor concentration as monitored by [125I]-oFSH binding to isolated cells. The newly induced receptors were kinetically indistinguishable from the preexisting ones, as determined by Lineweaver-Burk plot of the binding data. The induced receptors were functional as evidenced by increased ability of the granulosa cells to incorporate [3H]-leucine into cellular proteins. Neutralization of endogenous follicle stimulating hormone and luteinizing hormone by administering specific antisera had no effect on the ability of diethylstilbesterol to induce follicle stimulating hormone receptors, whereas blockade of endogenous prolactin secretion by ergobromocryptin administration significantly inhibited (∼ 30 %) the response to diethylstilbesterol; this inhibition could be completely relieved by ovine prolactin treatment. However, ovine prolactin at the dose tried did not by itself enhance follicle stimulating hormone receptor level. Administration of ergobromocryptin to adult cycling rats at noon of proestrus brought about as measured on diestrusII, (a) a reduction of both follicle stimulating hormone (∼ 30 %) and luteinizing hormone (∼ 45 %) receptor concentration in granulosa cells, (b) a drastic reduction in the ovarian tissue estradiol with no change in tissue progesterone and (c) reduction in the ability of isolated granulosa cells to convert testosterone to estradiol in response to follicle stimulating hormone. Ergobromocryptin treatment affected only prolactin and not follicle stimulating hormone or luteinizing hormone surges on the proestrus evening. Treatment of rats with ergobromocryptin at proestrus noon followed by an injection of ovine prolactin (1 mg) at 1700 h of the same day completely reversed the ergobromocryptin induced reduction in ovarian tissue estradiol as well as the aromatase activity of the granulosa cells on diestrus II, thus suggesting a role for proestrus prolactin surge in the follicular maturation process.

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The relative induction of FSH and LH receptors in the granulosa cells of immature rat ovary by pregnant mare serum gonadotropin (PMSG) has been studied. A single injection of PMSG (15 IU) brought about a 3- and 12-fold increase in FSH and LH receptor concentration,respectively, in the granulosa cells. Maximal concentration was reached by 72 h but the receptor levels showed a sharp decline during the next 24–48 h. The kinetic properties of the newly formed FSH receptors were indistinguishable from the pre-existing ones. The induced FSH receptors were functional as demonstrated by an increase in the in vitro responsiveness of the cells to exogenous FSH in terms of progesterone production. Treatment of immature rats with cyanoketone, an inhibitor of Δ5,3β-hydroxysteroid dehydrogenase, prior to PMSG injection effectively reduced the PMSG-stimulated increase in the serum estradiol, uterine weight and LH receptors but had no effect on the FSH receptor induction. The ability of PMSG to induce gonadotropin receptors can be arrested at any given time by injecting its antibody, thereby suggesting a continuous need for the hormonal inducer. Estrogen in the absence of the primary inducer was unable to maintain the induced LH and FSH receptor concentration. Inhibition of prostaglandin synthesis using indomethacin also had no effect on either the induction or degradation of gonadotropin receptors. Administration of PMSG antiserum, 48 h after PMSG injection, brought about a rapid decline in the induced receptors over the next 24 h, with a rate constant and \iota 1/2 of 0.078 h−1 and 8.9 h for FSH receptors and 0.086 h−1 and 8.0 h for the LH receptors, respectively.

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We reported the presence of a 80 kDa polypeptide in porcine follicular fluid that inhibited the binding of 125I-radiolabelled hFSH as well as hCG to the rat ovarian gonadotropin receptors. In the present study, the biological activity of the receptor binding inhibitor is determined using an in vitro bioassay procedure. Granulosa cells isolated from PMSG primed immature rat ovaries respond to exogenously added gonadotropins in terms of progesterone production. Addition of fractions containing the gonadotropin receptor binding inhibitory activity inhibited progesterone production stimulated by the gonadotropins in a dose-dependent fashion. The receptor binding inhibitory activity was also capable of inhibiting progesterone production stimulated by PMSG, which has both FSH- and LH-like activities in rats. In contrast, progesterone production stimulated by dbcAMP was not inhibited by the receptor binding inhibitor. This result indicates that the site of action of the inhibitor is proximal to the formation of the cAMP. The above observations point out to a possible role for this factor in modulating gonadotropin activity at the ovarian level.

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The presence of progesterone receptors (PR) in the human placenta has been demonstrated using the reverse transcriptase-polymerase chain reaction technique. It was observed that the amount of PR in the human placenta is less during late gestation. Electrophoretic mobility shift assays with nuclear extract isolated from the first trimester and term placenta revealed three complexes when incubated with [P-32]dCTP-labelled progesterone response element, and, in competition with unlabelled progesterone response element, the formation of all three complexes was inhibited. When supershift analysis of these complexes was carried out using antibodies which cross-react with both the A and B types of the PR or only with the B type receptor, only the A-form of PR was detected in the human placenta.

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Background: As trials of 5 years of tamoxifen in early breast cancer mature, the relevance of hormone receptor measurements (and other patient characteristics) to long-term outcome can be assessed increasingly reliably. We report updated meta-analyses of the trials of 5 years of adjuvant tamoxifen.
Methods: We undertook a collaborative meta-analysis of individual patient data from 20 trials (n=21457) in early breast cancer of about 5 years of tamoxifen versus no adjuvant tamoxifen, with about 80% compliance. Recurrence and death rate ratios (RRs) were from log-rank analyses by allocated treatment.
Findings: In oestrogen receptor (ER)-positive disease (n=10 645), allocation to about 5 years of tamoxifen substantially reduced recurrence rates throughout the first 10 years (RR 0.53 [SE 0.03] during years 0-4 and RR 0.68 [0.06] during years 5-9 [both 2p<0.00001]; but RR 0.97 [0.10] during years 10-14, suggesting no further gain or loss after year 10). Even in marginally ER-positive disease (10-19 fmol/mg cytosol protein) the recurrence reduction was substantial (RR 0.67 [0.08]). In ER-positive disease, the RR was approximately independent of progesterone receptor status (or level), age, nodal status, or use of chemotherapy. Breast cancer mortality was reduced by about a third throughout the first 15 years (RR 0.71 [0.05] during years 0-4, 0.66 [0.05] during years 5-9, and 0.68 [0.08] during years 10-14; p<0.0001 for extra mortality reduction during each separate time period). Overall non-breast-cancer mortality was little affected, despite small absolute increases in thromboembolic and uterine cancer mortality (both only in women older than 55 years), so all-cause mortality was substantially reduced. In ER-negative disease, tamoxifen had little or no effect on breast cancer recurrence or mortality.
Interpretation: 5 years of adjuvant tamoxifen safely reduces 15-year risks of breast cancer recurrence and death. ER status was the only recorded factor importantly predictive of the proportional reductions. Hence, the absolute risk reductions produced by tamoxifen depend on the absolute breast cancer risks (after any chemotherapy) without tamoxifen.
Funding: Cancer Research UK, British Heart Foundation, and Medical Research Council.