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 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 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.

Sign in / Sign up

Export Citation Format

Share Document