W

bioLLM/wiki

LLM-Synthesized Biotech Database

Live

oestrogen receptor

oestrogen receptor

Overview

The oestrogen receptor (ER) is a nuclear hormone receptor protein that mediates the biological effects of oestrogens and is a central regulator of growth, differentiation, and survival in hormone-responsive tissues. In clinical oncology, ER status is one of the most important biomarkers in breast cancer, where estrogen receptor-positive (ER+) disease is defined by receptor expression and is commonly used to guide diagnosis, prognosis, and treatment selection.

Biologically, ER functions as a transcriptional regulator that can influence gene expression programs involved in cell proliferation and endocrine responsiveness. Its activity is especially relevant in breast malignancy, where ER signaling drives growth in many tumors and interacts with other pathways such as androgen receptor signaling, HER2, IGF-related signaling, and lipid-derived mediators. Because of this central role, ER is both a diagnostic marker and a therapeutic target, particularly in the context of endocrine therapy and selective ER degraders.

Focus of Latest Publications

Recent publications in the provided set reinforce the central role of oestrogen receptor in breast cancer biology, molecular subtyping, and endocrine treatment response.

Several studies used ER as a defining marker for breast cancer classification. A clinical service evaluation protocol for deep-learning-based whole-slide image analysis noted that histological diagnosis still requires additional testing for estrogen receptor (ER), progesterone receptor (PR), and HER2 status, underscoring ER’s role in routine molecular marker subtyping. Another study in Palestinian women examined relationships among IGFBP-3, IGF-1, an IGFBP-3 polymorphism, and hormone receptor subtypes including ER, PR, and HER2 in relation to breast cancer risk. This indicates that ER status remains a key stratification variable in epidemiologic and biomarker research.

ER was also central to studies of disease biology and treatment resistance. One report stated that the estrogen receptor drives growth in most breast cancers, and another investigated how endocrine therapy reprogramming can facilitate metastatic escape through upregulation of P-Rex1/Rac1 signaling. These findings place ER at the center of endocrine dependence and adaptive resistance mechanisms in metastatic breast cancer. A separate case report on very late recurrence highlighted the clinical importance of ER-positive disease, reflecting the long-term relevance of ER status in recurrence risk and follow-up.

Therapeutic targeting of ER was also directly represented. The extracted methods include tamoxifen and selective ER degraders, indicating that some studies focused on canonical endocrine therapies and receptor downregulation strategies. In the context of breast cancer recurrence and endocrine resistance, these approaches are consistent with the established use of ER-directed treatment to suppress hormone-driven tumor growth.

The recent literature also shows ER being studied in relation to other signaling systems and disease contexts. A paper on 27-hydroxycholesterol reported that this oxysterol exerts pathophysiological effects via estrogen receptor- and liver X receptor (LXR)-mediated pathways, linking ER to lipid signaling and adipocyte biology. Another study on granulomatous lobular mastitis included assessment of ER and PR expression in mammary gland tissue after treatment, showing that ER is also used as a tissue biomarker outside classic malignancy settings. In addition, a proteomic study of triple-negative breast cancer emphasized the absence of ER, PR, and HER2, illustrating ER’s role in defining a clinically distinct subtype.

One of the most notable recent directions is the exploration of androgen receptor (AR) agonism as a treatment strategy in ER-positive metastatic breast cancer. This work reported that AR is expressed in a large proportion of ER+ breast cancers, supporting the idea that AR and ER signaling may be biologically intertwined. Related extracted therapies such as selective AR modulators suggest that investigators are examining receptor crosstalk and alternative endocrine strategies in tumors that remain ER-driven but may escape standard therapy.

Overall, the recent studies portray oestrogen receptor as:

  • a core diagnostic biomarker in breast cancer,
  • a driver of hormone-dependent tumor growth,
  • a determinant of endocrine therapy selection,
  • a marker of subtype and prognosis,
  • and a node in broader signaling networks involving AR, HER2, IGF pathways, and oxysterol biology.

Key Publications

  • Jun Exploiting androgen receptor agonism as a treatment strategy in estrogen receptor-positive metastatic breast cancer. (NPJ breast cancer, 2026, PMID 42310300): "The androgen receptor (AR) is expressed in 75% of estrogen receptor-positive (ER+) breast cancers (BC)."
  • Jun Deep-Learning Solution Providing Molecular Marker Subtyping of Breast Cancer Whole Slide Images: Protocol for a UK Clinical Service Evaluation Study. (JMIR research protocols, 2026, PMID 42302265): "...requires additional testing for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER2) status at the time of histological diagnosis."
  • Jan Interplay of the IGFBP-3 polymorphism and serum levels of IGF-1/IGFBP-3 with hormone receptor subtypes in patients with breast cancer among Palestinian women. (PloS one, 2026, PMID 42224209): "This study aimed to investigate the relationships between serum levels of insulin-like growth factor binding protein 3 (IGFBP-3), insulin-like growth factor 1 (IGF-1), the IGFBP-3 A-202C polymorphism and hormone receptor subtypes: estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2) with respect to breast cancer risk in Palestinian women."
  • May Therapeutic effects of Tuolitounong decoction on pyroptosis in granulomatous lobular mastitis: evidence from in vitro and in vivo models. (Journal of molecular histology, 2026, PMID 42142128): "Post-treatment evaluations included histopathological assessment, expression of estrogen receptor (ER) and progesterone receptor (PR), and pyroptosis-related biomarkers in mammary gland tissue."
  • May Endocrine therapy reprogramming of breast cancer facilitates metastatic escape via upregulation of P-Rex1/Rac1 signalling. (Nature communications, 2026, PMID 42115169): "The estrogen receptor (ER) drives growth in most breast cancers."
  • May 27-hydroxycholesterol is a regulatory oxysterol in adipocytes. (Biochimica et biophysica acta. Molecular and cell biology of lipids, 2026, PMID 41794211): "27HC exerts pathophysiological effects via estrogen receptor (ER)- and liver X receptor (LXR)-mediated pathways."
  • May Breast Cancer Recurrence After 46 Years of Remission: A Case Report and Clinical Implications. (In vivo (Athens, Greece), 2026, PMID 42049437): "especially in estrogen receptor-positive (ER+) disease."
  • Apr Proteomic signatures in triple-negative breast cancer. (Journal of proteomics, 2026, PMID 41512917): "is characterised by the absence of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2."
Content is generated using Large Language Models (LLMs) and may contain errors or hallucinations. Experts periodically review it to verify accuracy and maintain database integrity.