Progesterone receptor, androgen receptor, and estrogen receptor (PR, AR, ER)

The Progesterone Receptor (PR), Androgen Receptor (AR), and Estrogen Receptor (ER) are members of the nuclear receptor superfamily of ligand-activated transcription factors that mediate the physiological effects of steroid hormones (1). These receptors share a modular structure consisting of a highly conserved DNA-binding domain and a C-terminal ligand-binding domain, which allow them to regulate the expression of specific gene networks involved in reproduction, development, and cellular homeostasis (2). In clinical oncology, these receptors are both critical therapeutic targets and essential biomarkers; for instance, ER and PR status are used to guide treatment for breast cancer, while AR signaling is the primary driver and therapeutic focus in prostate cancer (3, 5). Pharmacological interventions typically involve selective receptor modulators, competitive antagonists to block hormone-driven tumor growth, or agonists for hormone replacement therapies (4). Because these receptors are widely expressed across various tissues, drug-induced modulation can lead to systemic side effects, including metabolic changes, cardiovascular risks, and bone density loss (5). (Sources: 1. UniProt [P03372, P04150, P06401]; 2. NIH/StatPearls - Steroid Hormones; 3. NCI - Hormone Therapy; 4. PubChem; 5. PubMed - Endocrine Therapy Side Effects)

Other names

Steroid hormone receptorsNuclear receptor subfamily 3Sex hormone receptorsNR3A1 (ER-alpha)NR3C3 (PR)NR3C4 (AR)

These targets function as ligand-dependent transcription factors; drugs act by binding to the ligand-binding domain (LBD) to either activate (agonism) or competitively inhibit (antagonism) the recruitment of co-activators and subsequent gene expression (1, 4).