8DUI

Estrogen Receptor Alpha Ligand Binding Domain in Complex with (1'-(4-(2-(dimethylamino)ethoxy)phenyl)-6'-hydroxy-1',4'-dihydro-2'H-spiro[cyclopropane-1,3'-isoquinolin]-2'-yl)(phenyl)methanone

Summary for 8DUI

• Entry DOI: 10.2210/pdb8dui/pdb
• Descriptor: Estrogen receptor, [(1'R)-1'-{4-[2-(dimethylamino)ethoxy]phenyl}-6'-hydroxy-1',4'-dihydro-2'H-spiro[cyclopropane-1,3'-isoquinolin]-2'-yl](phenyl)methanone (3 entities in total)
• Functional Keywords: antiestrogen, breast cancer, alpha helical bundle, estrogen receptor, transcription
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 2
• Total formula weight: 58951.13

Authors

Hancock, G.R.,Young, K.S.,Hosfield, D.J.,Joiner, C.,Sullivan, E.A.,Yildz, Y.,Laine, M.,Greene, G.L.,Fanning, S.W. (deposition date: 2022-07-27, release date: 2022-11-09, Last modification date: 2023-10-25)

Primary citation

Hancock, G.R.,Young, K.S.,Hosfield, D.J.,Joiner, C.,Sullivan, E.A.,Yildiz, Y.,Laine, M.,Greene, G.L.,Fanning, S.W.
Unconventional isoquinoline-based SERMs elicit fulvestrant-like transcriptional programs in ER+ breast cancer cells.
NPJ Breast Cancer, 8:130-130, 2022

PubMed Abstract: Estrogen receptor alpha (ERα) is a ligand-dependent master transcriptional regulator and key driver of breast cancer pathology. Small molecule hormones and competitive antagonists favor unique ERα conformational ensembles that elicit ligand-specific transcriptional programs in breast cancer and other hormone-responsive tissues. By affecting disparate ligand binding domain structural features, unconventional ligand scaffolds can redirect ERα genomic binding patterns to engage novel therapeutic transcriptional programs. To improve our understanding of these ERα structure-transcriptional relationships, we develop a series of chemically unconventional antagonists based on the antiestrogens elacestrant and lasofoxifene. High-resolution x-ray co-crystal structures show that these molecules affect both classical and unique structural motifs within the ERα ligand binding pocket. They show moderately reduced antagonistic potencies on ERα genomic activities but are effective anti-proliferative agents in luminal breast cancer cells. Interestingly, they favor a 4-hydroxytamoxifen-like accumulation of ERα in breast cancer cells but lack uterotrophic activities in an endometrial cell line. Importantly, RNA sequencing shows that the lead molecules engage transcriptional pathways similar to the selective estrogen receptor degrader fulvestrant. This advance shows that fulvestrant-like genomic activities can be achieved without affecting ERα accumulation in breast cancer cells.

PubMed: 36517522
DOI: 10.1038/s41523-022-00497-9

Experimental method

X-RAY DIFFRACTION (2.04 Å)