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 Molecular Mechanisms of Endocrine Resistance in Estrogen-Positive Breast Cancer

2021 ◽  
Vol 12 ◽  
Author(s):  
Esmael Besufikad Belachew ◽  
Dareskedar Tsehay Sewasew
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Endocrine Therapy ◽  
Molecular Mechanisms ◽  
De Novo ◽  
Endocrine Resistance ◽  
Therapeutic Modality ◽  
Breast Cancers ◽  
Estrogen Receptor Positive ◽  
Positive Breast Cancer

The estrogen receptor is a vital receptor for therapeutic targets in estrogen receptor-positive breast cancer. The main strategy for the treatment of estrogen receptor-positive breast cancers is blocking the estrogen action on estrogen receptors by endocrine therapy but this can be restricted via endocrine resistance. Endocrine resistance occurs due to both de novo and acquired resistance. This review focuses on the mechanisms of the ligand-dependent and ligand-independent pathways and other coregulators, which are responsible for endocrine resistance. It concludes that combinatorial drugs that target different signaling pathways and coregulatory proteins together with endocrine therapy could be a novel therapeutic modality to stop endocrine resistance.

scholarly journals MiR-195 and Its Target SEMA6D Regulate Chemoresponse in Breast Cancer

Cancers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 5979
Author(s):  
Diana E. Baxter ◽  
Lisa M. Allinson ◽  
Waleed S. Al Amri ◽  
James A. Poulter ◽  
Arindam Pramanik ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Cell Lines ◽  
Target Genes ◽  
Breast Cancer Cell Lines ◽  
Molecular Characteristics ◽  
Chemotherapy Response ◽  
Breast Cancers ◽  
Microrna Target ◽  
Estrogen Receptor Positive

Background: poor prognosis primary breast cancers are typically treated with cytotoxic chemotherapy. However, recurrences remain relatively common even after this aggressive therapy. Comparison of matched tumours pre- and post-chemotherapy can allow identification of molecular characteristics of therapy resistance and thereby potentially aid discovery of novel predictive markers or targets for chemosensitisation. Through this comparison, we aimed to identify microRNAs associated with chemoresistance, define microRNA target genes, and assess targets as predictors of chemotherapy response. Methods: cancer cells were laser microdissected from matched breast cancer tissues pre- and post-chemotherapy from estrogen receptor positive/HER2 negative breast cancers showing partial responses to epirubicin/cyclophosphamide chemotherapy (n = 5). MicroRNA expression was profiled using qPCR arrays. MicroRNA/mRNA expression was manipulated in estrogen receptor positive/HER2 negative breast cancer cell lines (MCF7 and MDA-MB-175 cells) with mimics, inhibitors or siRNAs, and chemoresponse was assessed using MTT and colony forming survival assays. MicroRNA targets were identified by RNA-sequencing of microRNA mimic pull-downs, and comparison of these with mRNAs containing predicted microRNA binding sites. Survival correlations were tested using the METABRIC expression dataset (n = 1979). Results: miR-195 and miR-26b were consistently up-regulated after therapy, and changes in their expression in cell lines caused significant differences in chemotherapy sensitivity, in accordance with up-regulation driving resistance. SEMA6D was defined and confirmed as a target of the microRNAs. Reduced SEMA6D expression was significantly associated with chemoresistance, in accordance with SEMA6D being a down-stream effector of the microRNAs. Finally, low SEMA6D expression in breast cancers was significantly associated with poor survival after chemotherapy, but not after other therapies. Conclusions: microRNAs and their targets influence chemoresponse, allowing the identification of SEMA6D as a predictive marker for chemotherapy response that could be used to direct therapy or as a target in chemosensitisation strategies.

scholarly journals The Central Contributions of Breast Cancer Stem Cells in Developing Resistance to Endocrine Therapy in Estrogen Receptor (ER)-Positive Breast Cancer

Cancers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1028 ◽  
Author(s):  
David Rodriguez ◽  
Marc Ramkairsingh ◽  
Xiaozeng Lin ◽  
Anil Kapoor ◽  
Pierre Major ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Estrogen Receptor ◽  
Cancer Stem Cells ◽  
Hormone Therapy ◽  
Endocrine Therapy ◽  
Endocrine Resistance ◽  
Therapy Resistance ◽  
Breast Cancer Stem Cells ◽  
Er Positive

Breast cancer stem cells (BCSC) play critical roles in the acquisition of resistance to endocrine therapy in estrogen receptor (ER)-positive (ER + ve) breast cancer (BC). The resistance results from complex alterations involving ER, growth factor receptors, NOTCH, Wnt/β-catenin, hedgehog, YAP/TAZ, and the tumor microenvironment. These mechanisms are likely converged on regulating BCSCs, which then drive the development of endocrine therapy resistance. In this regard, hormone therapies enrich BCSCs in ER + ve BCs under both pre-clinical and clinical settings along with upregulation of the core components of “stemness” transcriptional factors including SOX2, NANOG, and OCT4. SOX2 initiates a set of reactions involving SOX9, Wnt, FXY3D, and Src tyrosine kinase; these reactions stimulate BCSCs and contribute to endocrine resistance. The central contributions of BCSCs to endocrine resistance regulated by complex mechanisms offer a unified strategy to counter the resistance. ER + ve BCs constitute approximately 75% of BCs to which hormone therapy is the major therapeutic approach. Likewise, resistance to endocrine therapy remains the major challenge in the management of patients with ER + ve BC. In this review we will discuss evidence supporting a central role of BCSCs in developing endocrine resistance and outline the strategy of targeting BCSCs to reduce hormone therapy resistance.

Tracking endocrine resistance in estrogen-receptor positive breast cancer in ctDNA.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e14550-e14550
Author(s):  
Magdalena Meissner ◽  
Rachel Butler ◽  
Angela Claire Casbard ◽  
Margherita Carucci ◽  
Tracie-Ann Madden ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Endocrine Therapy ◽  
Initial Period ◽  
Single Agent ◽  
Endocrine Resistance ◽  
Gene Panel ◽  
Comparable Efficacy ◽  
Liquid Biopsies ◽  
Estrogen Receptor Positive

e14550 Background: Endocrine therapy is the standard of care treatment for patients with estrogen-receptor positive advanced breast cancer, owing to improved tolerability and comparable efficacy to that of cytotoxic chemotherapy. Half of such cancers will progress through first line therapy (primary endocrine resistance) and half will progress after an initial period of disease control (secondary or acquired endocrine resistance). A significant challenge is to test for and identify biomarkers which can guide the likely success of endocrine therapy as a single agent or in combination with small molecule inhibitors.This is particularly challenging where metastatic deposits reside at sites where biopsy is difficult. Potential biomarkers indicative of resistance to endocrine therapy have been identified and can be detected in circulating tumour DNA (ctDNA). CtDNA is shed from tumours and is detectable in a cancer patient’s bloodstream. Information on mutational profiles can guide an oncologist in the selection of targeted therapy in addition to hormonal therapy. Methods: We have analysed formalin-fixed paraffin-embedded(FFPE) tumour samples and longitudinal liquid biopsies from 19 patients who were treated with fulvestrant in combination with a novel inhibitor of the PIK3CA/AKT pathway with next-generation sequencing using a targeted 44-gene panel. Mutations identified using this technique were tracked during the course of treatment using droplet-digital PCR(ddPCR). Results: 57 samples were tested using a 44-gene panel; 19 FFPE tumour samples and matched ctDNA samples were obtained prior therapy and ctDNA samples at disease progression. Mutations detected in PIK3CA, AKT1, ESR1and TP53 genes were trackable in longitudinal ctDNA samples using ddPCR. The association between ctDNA dynamics and outcome will be presented. Conclusions: Multiple mutations that enable the early detection of treatment failure and resistance can be tracked in ctDNA. Investigating the clinical utility of ctDNA is paramount.

scholarly journals Estrogen-regulated feedback loop limits the efficacy of estrogen receptor–targeted breast cancer therapy

2018 ◽  
Vol 115 (31) ◽  
pp. 7869-7878 ◽  
Author(s):  
Tengfei Xiao ◽  
Wei Li ◽  
Xiaoqing Wang ◽  
Han Xu ◽  
Jixin Yang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Endocrine Therapy ◽  
Negative Feedback ◽  
Feedback Loop ◽  
Therapy Resistance ◽  
Negative Feedback Loop ◽  
Endocrine Therapy Resistance ◽  
Estrogen Receptor Positive ◽  
Underlying Mechanisms

Endocrine therapy resistance invariably develops in advanced estrogen receptor-positive (ER+) breast cancer, but the underlying mechanisms are largely unknown. We have identified C-terminal SRC kinase (CSK) as a critical node in a previously unappreciated negative feedback loop that limits the efficacy of current ER-targeted therapies. Estrogen directly drives CSK expression in ER+ breast cancer. At low CSK levels, as is the case in patients with ER+ breast cancer resistant to endocrine therapy and with the poorest outcomes, the p21 protein-activated kinase 2 (PAK2) becomes activated and drives estrogen-independent growth. PAK2 overexpression is also associated with endocrine therapy resistance and worse clinical outcome, and the combination of a PAK2 inhibitor with an ER antagonist synergistically suppressed breast tumor growth. Clinical approaches to endocrine therapy-resistant breast cancer must overcome the loss of this estrogen-induced negative feedback loop that normally constrains the growth of ER+ tumors.

scholarly journals Detection of ESR1 Mutations Based on Liquid Biopsy in Estrogen Receptor-Positive Metastatic Breast Cancer: Clinical Impacts and Prospects

2020 ◽  
Vol 10 ◽  
Author(s):  
Hao Liao ◽  
Wenfa Huang ◽  
Wendi Pei ◽  
Huiping Li
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Endocrine Therapy ◽  
Liquid Biopsy ◽  
Endocrine Resistance ◽  
Metastatic Breast ◽  
Favorable Prognosis ◽  
Sequencing Technologies ◽  
Estrogen Receptor Positive ◽  
Almost All

Endocrine therapy is the main treatment option for estrogen receptor-positive (ER+) breast cancer (BC). Compared with other clinical subtypes, ER+ BC patients usually have a more favorable prognosis. However, almost all ER+ BCpatients develop endocrine resistance and disease progression eventually. A large number of studies based on liquid biopsy suggest that ESR1 mutations may play a key role in this process. For patients with ER+ metastatic BC (MBC), ESR1 is an important prognostic factor and may associate with the resistance to endocrine therapy, like aromatase inhibitors. The advances of sequencing technologies allow us to conduct longitudinal monitoring of disease and unveil the clinical implications of each ESR1 sub-clone in ER+ MBC. Moreover, since the ESR1-related endocrine resistance has not been fully addressed by existing agents, more potent cornerstone drugs should be developed as soon as possible. Herein, we reviewed the recent progress of detecting ESR1 mutations based on liquid biopsy and different sequencing technologies in ER+ MBC and discussed its clinical impacts and prospects.

scholarly journals Genomic profiling of ER+ breast cancers after short-term estrogen suppression reveals alterations associated with endocrine resistance

2017 ◽  
Vol 9 (402) ◽  
pp. eaai7993 ◽  
Author(s):  
Jennifer M. Giltnane ◽  
Katherine E. Hutchinson ◽  
Thomas P. Stricker ◽  
Luigi Formisano ◽  
Christian D. Young ◽  
...  
Keyword(s):  
Endocrine Therapy ◽  
Endocrine Resistance ◽  
Growth Factor Receptor ◽  
Therapy Resistance ◽  
Genomic Profiling ◽  
Breast Cancers ◽  
Short Term ◽  
Endocrine Therapy Resistance ◽  
Inhibition Of Proliferation ◽  
Estrogen Receptor Positive

Inhibition of proliferation in estrogen receptor–positive (ER+) breast cancers after short-term antiestrogen therapy correlates with long-term patient outcome. We profiled 155 ER+/human epidermal growth factor receptor 2–negative (HER2−) early breast cancers from 143 patients treated with the aromatase inhibitor letrozole for 10 to 21 days before surgery. Twenty-one percent of tumors remained highly proliferative, suggesting that these tumors harbor alterations associated with intrinsic endocrine therapy resistance. Whole-exome sequencing revealed a correlation between 8p11-12 and 11q13 gene amplifications, including FGFR1 and CCND1, respectively, and high Ki67. We corroborated these findings in a separate cohort of serial pretreatment, postneoadjuvant chemotherapy, and recurrent ER+ tumors. Combined inhibition of FGFR1 and CDK4/6 reversed antiestrogen resistance in ER+FGFR1/CCND1 coamplified CAMA1 breast cancer cells. RNA sequencing of letrozole-treated tumors revealed the existence of intrachromosomal ESR1 fusion transcripts and increased expression of gene signatures indicative of enhanced E2F-mediated transcription and cell cycle processes in cancers with high Ki67. These data suggest that short-term preoperative estrogen deprivation followed by genomic profiling can be used to identify druggable alterations that may cause intrinsic endocrine therapy resistance.

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