scholarly journals Modulating HSF1 levels impacts expression of the estrogen receptor α and antiestrogen response

2021 ◽  
Vol 4 (5) ◽  
pp. e202000811
Author(s):  
Maruhen AD Silveira ◽  
Christophe Tav ◽  
Félix-Antoine Bérube-Simard ◽  
Tania Cuppens ◽  
Mickaël Leclercq ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Endocrine Resistance ◽  
Estrogen Receptor Α ◽  
Heat Shock Factor 1 ◽  
Antiestrogen Resistance ◽  
Breast Cancers ◽  
Proof Of Concept ◽  
Transcriptional Program ◽  
Cellular Functions

Master transcription factors control the transcriptional program and are essential to maintain cellular functions. Among them, steroid nuclear receptors, such as the estrogen receptor α (ERα), are central to the etiology of hormone-dependent cancers which are accordingly treated with corresponding endocrine therapies. However, resistance invariably arises. Here, we show that high levels of the stress response master regulator, the heat shock factor 1 (HSF1), are associated with antiestrogen resistance in breast cancer cells. Indeed, overexpression of HSF1 leads to ERα degradation, decreased expression of ERα-activated genes, and antiestrogen resistance. Furthermore, we demonstrate that reducing HSF1 levels reinstates expression of the ERα and restores response to antiestrogens. Last, our results establish a proof of concept that inhibition of HSF1, in combination with antiestrogens, is a valid strategy to tackle resistant breast cancers. Taken together, we are proposing a mechanism where high HSF1 levels interfere with the ERα-dependent transcriptional program leading to endocrine resistance in breast cancer.

scholarly journals Nuclear Mechanisms Involved in Endocrine Resistance

2021 ◽  
Vol 11 ◽  
Author(s):  
Jürgen Dittmer
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Endocrine Therapy ◽  
Standard Treatment ◽  
Current Knowledge ◽  
Endocrine Resistance ◽  
Estrogen Receptor Α ◽  
Cyclin Dependent Kinase ◽  
Druggable Targets ◽  
Positive Breast Cancer

Endocrine therapy is a standard treatment offered to patients with ERα (estrogen receptor α)-positive breast cancer. In endocrine therapy, ERα is either directly targeted by anti-estrogens or indirectly by aromatase inhibitors which cause estrogen deficiency. Resistance to these drugs (endocrine resistance) compromises the efficiency of this treatment and requires additional measures. Endocrine resistance is often caused by deregulation of the PI3K/AKT/mTOR pathway and/or cyclin-dependent kinase 4 and 6 activities allowing inhibitors of these factors to be used clinically to counteract endocrine resistance. The nuclear mechanisms involved in endocrine resistance are beginning to emerge. Exploring these mechanisms may reveal additional druggable targets, which could help to further improve patients’ outcome in an endocrine resistance setting. This review intends to summarize our current knowledge on the nuclear mechanisms linked to endocrine resistance.

scholarly journals Increased expression of the estrogen receptor alpha, ESR1, in the tumors of breast cancer patients treated with trastuzumab.

2020 ◽  
Author(s):  
Shahan Mamoor
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Estrogen Receptor Alpha ◽  
Estrogen Receptor Α ◽  
Needle Aspiration ◽  
Breast Cancers ◽  
Breast Cancer Patients ◽  
Primary Tumors ◽  
Transcriptional Induction ◽  
Selection Of

Hormones function as growth factors, and estrogen provides growth signals to support and induce the proliferation of breast cancers (1-3). This is the basis of the use of endocrine therapies (4, 5) including tamoxifen and letrozole as first-line treatment for patients with breast cancer. We found through mining published microarray and multiplexed gene expression profiling datasets that the estrogen receptor α (ESR1) was among the genes most differentially expressed in the primary tumors and fine needle aspiration-isolated tumor cells of patients with breast cancer treated with trastuzumab. However, estrogen receptor α was expressed at higher rather than lower levels in the tumors of trastuzumab-treated patients. These data, obtained through blind, systems-level analysis of published microarray data (6-8), suggest that trastuzumab administration in patients with breast cancer is associated with transcriptional induction of the estrogen receptor or selection of tumor clones with high expression of ESR1.

scholarly journals Combined Targeting of Estrogen Receptor Alpha and Exportin 1 in Metastatic Breast Cancers

Cancers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2397
Author(s):  
Eylem Kulkoyluoglu Cotul ◽  
Qianying Zuo ◽  
Ashlie Santaliz-Casiano ◽  
Ozan Berk Imir ◽  
Ayca Nazli Mogol ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Metabolic Pathways ◽  
Nuclear Export ◽  
Tumor Regression ◽  
Critical Role ◽  
Endocrine Resistance ◽  
Metastatic Breast ◽  
Metabolic Phenotype ◽  
Breast Cancers

The majority of breast cancer specific deaths in women with estrogen receptor positive (ER+) tumors occur due to metastases that are resistant to therapy. There is a critical need for novel therapeutic approaches to achieve tumor regression and/or maintain therapy responsiveness in metastatic ER+ tumors. The objective of this study was to elucidate the role of metabolic pathways that undermine therapy efficacy in ER+ breast cancers. Our previous studies identified Exportin 1 (XPO1), a nuclear export protein, as an important player in endocrine resistance progression and showed that combining selinexor (SEL), an FDA-approved XPO1 antagonist, synergized with endocrine agents and provided sustained tumor regression. In the current study, using a combination of transcriptomics, metabolomics and metabolic flux experiments, we identified certain mitochondrial pathways to be upregulated during endocrine resistance. When endocrine resistant cells were treated with single agents in media conditions that mimic a nutrient deprived tumor microenvironment, their glutamine dependence for continuation of mitochondrial respiration increased. The effect of glutamine was dependent on conversion of the glutamine to glutamate, and generation of NAD+. PGC1α, a key regulator of metabolism, was the main driver of the rewired metabolic phenotype. Remodeling metabolic pathways to regenerate new vulnerabilities in endocrine resistant breast tumors is novel, and our findings reveal a critical role that ERα-XPO1 crosstalk plays in reducing cancer recurrences. Combining SEL with current therapies used in clinical management of ER+ metastatic breast cancer shows promise for treating and keeping these cancers responsive to therapies in already metastasized patients.

Estrogen Receptor β

2011 ◽  
Vol 135 (1) ◽  
pp. 63-66 ◽  
Author(s):  
Mamoun Younes ◽  
Naoko Honma
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Tissue Distribution ◽  
English Literature ◽  
Estrogen Receptor Beta ◽  
Estrogen Receptor Α ◽  
Estrogen Receptor Β ◽  
Adjuvant Tamoxifen ◽  
Breast Cancers ◽  
New Class

Abstract Context—A new class of estrogen receptors was discovered in 1996 and named estrogen receptor β (ER-B); the traditional estrogen receptor, which until a little more than 10 years ago was thought of as the only estrogen receptor in existence, is now called estrogen receptor α. Estrogen receptor β has at least 5 isoforms, which may have different functions and have different tissue distribution. The significance of ER-B expression in tumors was first demonstrated in breast cancer, with several studies demonstrating that women with ER-B–positive breast cancers treated with adjuvant tamoxifen have better survival, independent of estrogen receptor α expression. Pathologists need to be more aware of this increasingly important protein, as it will soon find its way into routine clinical practice. Objective—To provide pathologists with a concise review of ER-B, with special emphasis on current and potential clinical relevance. Data Sources—A search of the English literature in PubMed (National Library of Medicine, Bethesda, Maryland) for articles with titles including “estrogen receptor beta,” with emphasis on “immunohistochemistry.” Abstracts were reviewed, and selected articles were used as the basis for writing this review, mostly based on their relevance to pathology. Conclusions—Estrogen receptor β and its isoforms have wider tissue distribution, including the gastrointestinal tract, lung, and brain, than the traditional estrogen receptor, now called estrogen receptor α. Estrogen receptor β expression in breast cancer is associated with favorable outcome in women treated with adjuvant tamoxifen, even in tumors negative for estrogen receptor α. The clinical significance of ER-B expression in tumors other than breast is currently under investigation.

scholarly journals Update on the Role of NFκB in Promoting Aggressive Phenotypes of Estrogen Receptor–Positive Breast Cancer

Endocrinology ◽  
2020 ◽  
Vol 161 (10) ◽  
Author(s):  
Emily Smart ◽  
Svetlana E Semina ◽  
Jonna Frasor
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Endocrine Therapy ◽  
Signaling Pathway ◽  
Endocrine Resistance ◽  
Dimethyl Fumarate ◽  
Therapy Resistance ◽  
Molecular Characteristics ◽  
Breast Cancers ◽  
Estrogen Receptor Positive

Abstract The majority of breast cancers are diagnosed as estrogen receptor–positive (ER+) and respond well to ER-targeted endocrine therapy. Despite the initial treatability of ER+ breast cancer, this subtype still accounts for the majority of deaths. This is partly due to the changing molecular characteristics of tumors as they progress to aggressive, metastatic, and frequently therapy resistant disease. In these advanced tumors, targeting ER alone is often less effective, as other signaling pathways become active, and ER takes on a redundant or divergent role. One signaling pathway whose crosstalk with ER has been widely studied is the nuclear factor kappa B (NFκB) signaling pathway. NFκB is frequently implicated in ER+ tumor progression to an aggressive disease state. Although ER and NFκB frequently co-repress each other, it has emerged that the 2 pathways can positively converge to play a role in promoting endocrine resistance, metastasis, and disease relapse. This will be reviewed here, paying particular attention to new developments in the field. Ultimately, finding targeted therapies that remain effective as tumors progress remains one of the biggest challenges for the successful treatment of ER+ breast cancer. Although early attempts to therapeutically block NFκB activity frequently resulted in systemic toxicity, there are some effective options. The drugs parthenolide and dimethyl fumarate have both been shown to effectively inhibit NFκB, reducing tumor aggressiveness and reversing endocrine therapy resistance. This highlights the need to revisit targeting NFκB in the clinic to potentially improve outcome for patients with ER+ breast cancer.

scholarly journals Heat Shock Factor 1 (HSF1) cooperates with estrogen receptor α (ERα) in the regulation of estrogen action in breast cancer cells

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Natalia Vydra ◽  
Patryk Janus ◽  
Paweł Kuś ◽  
Tomasz Stokowy ◽  
Katarzyna Mrowiec ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Heat Shock ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Estrogen Receptor Α ◽  
Heat Shock Factor ◽  
Heat Shock Factor 1 ◽  
Er Positive ◽  
Positive Breast Cancer

Heat shock factor 1 (HSF1), a key regulator of transcriptional responses to proteotoxic stress, was linked to estrogen (E2) signaling through estrogen receptor α (ERα). We found that an HSF1 deficiency may decrease ERα level, attenuate the mitogenic action of E2, counteract E2-stimulated cell scattering, and reduce adhesion to collagens and cell motility in ER-positive breast cancer cells. The stimulatory effect of E2 on the transcriptome is largely weaker in HSF1-deficient cells, in part due to the higher basal expression of E2-dependent genes, which correlates with the enhanced binding of unliganded ERα to chromatin in such cells. HSF1 and ERα can cooperate directly in E2-stimulated regulation of transcription, and HSF1 potentiates the action of ERα through a mechanism involving chromatin reorganization. Furthermore, HSF1 deficiency may increase the sensitivity to hormonal therapy (4-hydroxytamoxifen) or CDK4/6 inhibitors (palbociclib). Analyses of data from the TCGA database indicate that HSF1 increases the transcriptome disparity in ER-positive breast cancer and can enhance the genomic action of ERα. Moreover, only in ER-positive cancers, an elevated HSF1 level is associated with metastatic disease.

scholarly journals Endocrine Resistance in Breast Cancer

2014 ◽  
Vol 2014 ◽  
pp. 1-27 ◽  
Author(s):  
J. M. Dixon
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Disease Resistance ◽  
Estrogen Receptor Alpha ◽  
Endocrine Resistance ◽  
Breast Cancers ◽  
Resistance To Therapy ◽  
Receptor Alpha ◽  
Number Of Patients

Around 70% of all breast cancers are estrogen receptor alpha positive and hence their development is highly dependent on estradiol. While the invention of endocrine therapies has revolusioned the treatment of the disease, resistance to therapy eventually occurs in a large number of patients. This paper seeks to illustrate and discuss the complexity and heterogeneity of the mechanisms which underlie resistance and the approaches proposed to combat them. It will also focus on the use and development of methods for predicting which patients are likely to develop resistance.

scholarly journals PAK4 regulates stemness and progression in endocrine resistant ER-positive metastatic breast cancer

2019 ◽  
Author(s):  
Angélica Santiago-Gómez ◽  
Ilaria Dragoni ◽  
Roisin NicAmhlaoibh ◽  
Elisabeth Trivier ◽  
Verity Sabin ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Metastatic Breast Cancer ◽  
Disease Progression ◽  
Poor Prognosis ◽  
Acquired Resistance ◽  
Endocrine Resistance ◽  
Metastatic Breast ◽  
Breast Cancers ◽  
P21 Activated Kinase

AbstractDespite the effectiveness of endocrine therapies to treat estrogen receptor-positive (ER+) breast tumours, two thirds of patients will eventually relapse due tode novoor acquired resistance to these agents. Cancer Stem-like Cells (CSCs), a rare cell population within the tumour, accumulate after anti-estrogen treatments and are likely to contribute to their failure. Here we studied the role of p21-activated kinase 4 (PAK4) as a promising target to overcome endocrine resistance and disease progression in ER+ breast cancers. PAK4 predicts for resistance to tamoxifen and poor prognosis in 2 independent cohorts of ER+ tumours. We observed that PAK4 strongly correlates with CSC activity in metastatic patient-derived samples irrespective of breast cancer subtype. However, PAK4-driven mammosphere-forming CSC activity increases alongside progression only in ER+ metastatic samples. PAK4 activity increases in ER+ models during acquired resistance to endocrine therapies. Targeting PAK4 with either CRT PAKi, a small molecule inhibitor of PAK4, or with specific siRNAs abrogates CSC activity/self-renewal in clinical samples and endocrine-resistant cells. Together, our findings establish that PAK4 regulates stemness during disease progression and that its inhibition reverses endocrine resistance in ER+ breast cancers.HighlightsPAK4 predicts for failure of endocrine therapies and poor prognosisPAK4 drives stemness and progression in ER+ metastatic breast cancerTargeting PAK4 abrogates breast CSC activity and restores sensitivity to endocrine treatmentsTargeting PAK4 will improve outcome of ER+ breast cancer patientsList of Abbreviations that appeared in abstractCancer Stem-like Cells (CSCs)p21-activated kinase 4 (PAK4)Estrogen Receptor (ER)

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