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408 result(s) for "Estrogen Receptor alpha - biosynthesis"
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Clinical significance of the expression of autophagy-associated marker, beclin 1, in breast cancer patients who received neoadjuvant endocrine therapy
Background Neoadjuvant endocrine therapy (NAE) has been employed to improve surgical outcomes for hormone receptor-positive breast cancers in postmenopausal women. Endocrine responsiveness is estimated by expressions of hormone receptors, but its heterogeneity has been recognized. Autophagy is an evolutionally conserved process associated with cell survival and cell death and has been implicated in cancer treatment. Methods In order to examine the possible association between autophagy and response to endocrine therapy, we evaluated the status of autophagy-associated markers, beclin 1 and LC3, and apoptosis-associated markers, TUNEL and M30, in pre- and post-treatment specimens from 71 patients in a multicenter prospective study of neoadjuvant exemestane (JFMC34-0601). Results Immunoreactivity of the autophagy-associated markers, beclin 1 and LC3, in carcinoma cells increased in 14 % and 52 % of the patients, respectively, following the exemestane treatment. These increases were statistically significant (beclin 1, p  = 0.016, N  = 49; LC3, p  < 0.0001, N  = 33). The status of M30 immunoreactivity decreased ( p  = 0.008, N  = 47) and TUNEL remained unchanged ( N  = 53). In addition, tumors with pre-treatment stromal beclin 1 immunoreactivity revealed poor clinical and pathological responses compared with those without stromal beclin 1 immunoreactivity (25 % vs 67 % for clinical response, p  = 0.011, N  = 51; 0 % vs 41 % for pathological response, p  = 0.0081, N  = 49). Tumors with positive pre-treatment stromal beclin 1 had a higher baseline Ki-67 labeling index (both hot spot and overall average) than those without ( p  = 0.042 and 0.0075, respectively, N  = 53). Results of logistic regression analyses revealed that stromal beclin 1 was a predictor for clinical and pathological responses while ER, PR, Ki-67, and stromal LC3 expressions were not. Conclusions Results of our present study demonstrated that beclin 1 and LC3 immunoreactivity increased in carcinoma cells following exemestane treatment and that the status of pre-treatment stromal beclin 1 is associated with higher carcinoma cell proliferation and poor clinical and pathological responses to NAE. Trial registration UMIN C000000345 (2006/03/06)
A Systematic Study of the Impact of Estrogens and Selective Estrogen Receptor Modulators on Prostate Cancer Cell Proliferation
The estrogen signaling pathway has been reported to modulate prostate cancer (PCa) progression through the activity of estrogen receptors α and β (ERα and ERβ). Given that selective estrogen receptor modulators (SERMs) are used to treat breast cancer, ERs have been proposed as attractive therapeutic targets in PCa. However, many inconsistencies regarding the expression of ERs and the efficacy of SERMs for PCa treatment exist, notably due to the use of ERβ antibodies lacking specificity and treatments with high SERM concentrations leading to off-target effects. To end this confusion, our objective was to study the impact of estrogenic and anti-estrogenic ligands in well-studied in vitro PCa models with appropriate controls, dosages, and ER subtype-specific antibodies. When using physiologically relevant concentrations of nine estrogenic/anti-estrogenic compounds, including five SERMs, we observed no significant modulation of PCa cell proliferation. Using RNA-seq and validated antibodies, we demonstrate that these PCa models do not express ERs. In contrast, RNA-seq from PCa samples from patients have detectable expression of ERα. Overall, our study reveals that commonly used PCa models are inappropriate to study ERs and indicate that usage of alternative models is essential to properly assess the roles of the estrogen signaling pathway in PCa.
Connectional architecture of a mouse hypothalamic circuit node controlling social behavior
Type 1 estrogen receptor-expressing neurons in the ventrolateral subdivision of the ventromedial hypothalamus (VMHvlEsr1) play a causal role in the control of social behaviors, including aggression. Here we use six different viral-genetic tracing methods to systematically map the connectional architecture of VMHvlEsr1 neurons. These data reveal a high level of input convergence and output divergence (“fan-in/fan-out”) from and to over 30 distinct brain regions, with a high degree (∼90%) of bidirectionality, including both direct as well as indirect feedback. Unbiased collateralization mapping experiments indicate that VMHvlEsr1 neurons project to multiple targets. However, we identify two anatomically distinct subpopulations with anterior vs. posterior biases in their collateralization targets. Nevertheless, these two subpopulations receive indistinguishable inputs. These studies suggest an overall system architecture in which an anatomically feed-forward sensory-to-motor processing stream is integrated with a dense, highly recurrent central processing circuit. This architecture differs from the “brain-inspired,” hierarchical feed-forward circuits used in certain types of artificial intelligence networks.
Esr1+ cells in the ventromedial hypothalamus control female aggression
Esr1 + cells in the VMHvl are well known to influence female sexual behaviors. Here the authors find a surprising new role of this population in female aggression. They further reveal that the female VMHvl contains two molecularly and anatomically distinct subdivisions: one for aggression and one for sex. As an essential means of resolving conflicts, aggression is expressed by both sexes but often at a higher level in males than in females. Recent studies suggest that cells in the ventrolateral part of the ventromedial hypothalamus (VMHvl) that express estrogen receptor-α (Esr1) and progesterone receptor are essential for male but not female mouse aggression. In contrast, here we show that VMHvl Esr1+ cells are indispensable for female aggression. This population was active when females attacked naturally. Inactivation of these cells reduced female aggression whereas their activation elicited attack. Additionally, we found that female VMHvl contains two anatomically distinguishable subdivisions that showed differential gene expression, projection and activation patterns after mating and fighting. These results support an essential role of the VMHvl in both male and female aggression and reveal the existence of two previously unappreciated subdivisions in the female VMHvl that are involved in distinct social behaviors.
randomised study of the effects of letrozole and anastrozole on oestrogen receptor positive breast cancers in postmenopausal women
Introduction Changes in proliferation as measured by Ki67 occur within 14 days of starting treatment with an aromatase inhibitor and these changes have been shown to be predictors of long term outcome. This study aimed to compare changes in proliferation following 14 days of treatment with anastrozole and letrozole. Methods Two hundred and six women with 209 estrogen receptor (ER) positive operable breast cancers (three bilateral) were randomly allocated to receive either 14 days treatment with 2.5 mg of letrozole or 1 mg of anastrozole prior to surgery. Changes in expression of estrogen (ER) and progesterone receptors (PgR) as assessed by ALLRED scores and proliferation as assessed by Ki67 were analysed. The HER2 status of each tumour was also assessed using a combination of the Hercept test and FISH. Results Both letrozole and anastrozole reduced ER expression (ALLRED score) by a mean of 0.32 (0.20-0.44), P < 0.001 and PgR fell by a mean of 2.54 (2.20-2.89) P < 0.0001. Letrozole reduced proliferation from a geometric mean of 6.37% to 0.81%, P < 0.0001 and anastrozole reduced proliferation from 5.81% to 0.77%, P < 0.0001. There was no differences between drugs in the fall in ER, PgR or proliferation. Both letrozole and anastrozole produced significant falls in proliferation in both HER2 positive and HER2 negative cancers, all P < 0.001. Discussion 14 days of both letrozole and anastrozole reduces proliferation, ER and PgR expression. No significant difference between these two drugs was identified.
The mechanisms involved in the resistance of estrogen receptor-positive breast cancer cells to palbociclib are multiple and change over time
Purpose Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors are widely used for the treatment of advanced estrogen receptor (ER)-positive breast cancer. To develop a treatment strategy for cancers resistant to CDK4/6 inhibitors, here, we established palbociclib-resistant sublines and analyzed their resistance mechanisms. Methods Palbociclib-resistant sublines were established from T47D and MCF7 cells. Sensitivity to other drugs was assessed via the WST assay. Altered expression/phosphorylation of proteins related to signal transduction and cell cycle regulation was examined using western blotting. Copy number alterations and mutations in the retinoblastoma ( RB1 ) gene were also analyzed. Results Although an increase in CDK6 and decrease in retinoblastoma protein (Rb) expression/phosphorylation were commonly observed in the resistant sublines, changes in other cell cycle-related proteins were heterogeneous. Upon extended exposure to palbociclib, the expression/phosphorylation of these proteins became altered, and the long-term removal of palbociclib did not restore the Rb expression/phosphorylation patterns. Consistently a copy number decrease, as well as RB1 mutations were detected. Moreover, although the resistant sublines exhibited cross-resistance to abemaciclib, their response to dinaciclib was the same as that of wild-type cells. Of note, the cell line exhibiting increased mTOR phosphorylation also showed a higher sensitivity to everolimus. However, the sensitivity to chemotherapeutic agents was unchanged in palbociclib-resistant sublines. Conclusion ER-positive breast cancer cells use multiple molecular mechanisms to survive in the presence of palbociclib, suggesting that targeting activated proteins may be an effective strategy to overcome resistance. Additionally, palbociclib monotherapy induces mutations and copy number alterations in the RB1 gene.
The impact of luteal phase support on endometrial estrogen and progesterone receptor expression: a randomized control trial
Background To assess the impact of luteal phase support on the expression of estrogen receptor (ER) alpha and progesterone receptors B (PR-B) on the endometrium of oocyte donors undergoing controlled ovarian hyperstimulation (COH). Methods A prospective, randomized study was conducted in women undergoing controlled ovarian hyperstimulation for oocyte donation. Participants were randomized to receive no luteal support, vaginal progesterone alone, or vaginal progesterone plus orally administered 17 Beta estradiol. Endometrial biopsies were obtained at 4 time points in the luteal phase and evaluated by tissue microarray for expression of ER alpha and PR-B. Results One-hundred and eight endometrial tissue samples were obtained from 12 patients. No differences were found in expression of ER alpha and PR-B among all the specimens with the exception of one sample value. Conclusions The administration of progesterone during the luteal phase of COH for oocyte donor cycles, either with or without estrogen, does not significantly affect the endometrial expression of ER alpha and PR.
Temporal dynamic reorganization of 3D chromatin architecture in hormone-induced breast cancer and endocrine resistance
Recent studies have demonstrated that chromatin architecture is linked to the progression of cancers. However, the roles of 3D structure and its dynamics in hormone-dependent breast cancer and endocrine resistance are largely unknown. Here we report the dynamics of 3D chromatin structure across a time course of estradiol (E2) stimulation in human estrogen receptor α (ERα)-positive breast cancer cells. We identified subsets of temporally highly dynamic compartments predominantly associated with active open chromatin and found that these highly dynamic compartments showed higher alteration in tamoxifen-resistant breast cancer cells. Remarkably, these compartments are characterized by active chromatin states, and enhanced ERα binding but decreased transcription factor CCCTC-binding factor (CTCF) binding. We finally identified a set of ERα-bound promoter–enhancer looping genes enclosed within altered domains that are enriched with cancer invasion, aggressiveness or metabolism signaling pathways. This large-scale analysis expands our understanding of high-order temporal chromatin reorganization underlying hormone-dependent breast cancer. In breast cancer, the 3D architecture of the genome can impact gene regulation. Here, the authors use tethered chromatin conformation profiling to investigate 3D chromatin structure in models of hormone-induced breast cancer and endocrine resistance, finding dynamic temporal reorganisation.
Expression Patterns of ERα, ERβ, AR, SIRT1, SIRT2, and SIRT3 in Prostate Cancer Tissue and Normal Prostate Tissue
The purpose of this study was to examine the expression of estrogen receptor α (ERα) and β (ERβ), androgen receptor (AR), SIRT1, SIRT2 and SIRT3 in prostate cancer (PCa). From October 2010 to January 2015, 70 patients who had undergone radical prostatectomy following a PCa diagnosis were enrolled in our study. Normal prostate tissue (NPT) and prostate cancer tissues (PCAT) were separated, and the expression of each receptor in each tissue was analyzed with immunochemical staining. Univariate and multivariate analyses were performed to identify factors affecting the development of PCa. ERβ and AR were highly expressed in PCAT compared with NPT (p<0.05). SIRT2 was highly expressed in NPT and PCAT (p<0.05). Univariate and multivariate analyses showed that AR and SIRT2 affect PCa development. AR is a risk factor for PC, and SIRT2 is associated with a lower incidence of PCa.
Issues and updates: evaluating estrogen receptor-α, progesterone receptor, and HER2 in breast cancer
There are currently three prognostic/predictive biomarkers used in routine clinical management of patients with breast cancer, and their assessment is mandatory. They include estrogen receptor-alpha (ER α ), progesterone receptor (PgR), and the HER2 oncogene/oncoprotein. This paper briefly reviews the assessment of ER α , PgR, and HER2 in breast cancer, emphasizing recent progress and persistent controversies.