Structure-based Discovery of Antagonists of Nuclear Receptor LRH-1

• Published in: The Journal of biological chemistry 2013-07, Vol.288 (27), p.19830-19844
• Main Authors: Benod, Cindy, Carlsson, Jens, Uthayaruban, Rubatharshini, Hwang, Peter, Irwin, John J., Doak, Allison K., Shoichet, Brian K., Sablin, Elena P., Fletterick, Robert J.
• Format: Article
• Language: English
• Subjects: Antagonist; Cell Biology; Cell Proliferation - drug effects; Cyclin E - chemistry; Cyclin E - genetics; Cyclin E - metabolism; Drug Discovery; HEK293 Cells; HeLa Cells; Hormone Receptors; Humans; Inhibitor; Ligand-binding Protein; LRH-1; Molecular Docking; Molecular Probes - chemistry; Molecular Probes - pharmacology; Neoplasms - chemistry; Neoplasms - drug therapy; Neoplasms - genetics; Neoplasms - metabolism; Neoplasms - pathology; NR5A2; Nuclear Receptors; Oncogene Proteins - chemistry; Oncogene Proteins - genetics; Oncogene Proteins - metabolism; Receptors, Cytoplasmic and Nuclear - antagonists & inhibitors; Receptors, Cytoplasmic and Nuclear - chemistry; Receptors, Cytoplasmic and Nuclear - genetics; Receptors, Cytoplasmic and Nuclear - metabolism; Structure-Activity Relationship; Transcription Regulation
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M112.411686

Liver receptor homolog 1 (nuclear receptor LRH-1, NR5A2) is an essential regulator of gene transcription, critical for maintenance of cell pluripotency in early development and imperative for the proper functions of the liver, pancreas, and intestines during the adult life. Although physiological hormones of LRH-1 have not yet been identified, crystallographic and biochemical studies demonstrated that LRH-1 could bind regulatory ligands and suggested phosphatidylinositols as potential hormone candidates for this receptor. No synthetic antagonists of LRH-1 are known to date. Here, we identify the first small molecule antagonists of LRH-1 activity. Our search for LRH-1 modulators was empowered by screening of 5.2 million commercially available compounds via molecular docking followed by verification of the top-ranked molecules using in vitro direct binding and transcriptional assays. Experimental evaluation of the predicted ligands identified two compounds that inhibit the transcriptional activity of LRH-1 and diminish the expression of the receptor's target genes. Among the affected transcriptional targets are co-repressor SHP (small heterodimer partner) as well as cyclin E1 (CCNE1) and G0S2 genes that are known to regulate cell growth and proliferation. Treatments of human pancreatic (AsPC-1), colon (HT29), and breast adenocarcinoma cells T47D and MDA-MB-468 with the LRH-1 antagonists resulted in the receptor-mediated inhibition of cancer cell proliferation. Our data suggest that specific antagonists of LRH-1 could be used as specific molecular probes for elucidating the roles of the receptor in different types of malignancies. Background: Liver receptor homolog 1 (LRH-1, NR5A2) regulates functions of liver, intestines, and pancreas; its aberrant activity is associated with tumorigenesis. Results: Our work identifies the first antagonists of LRH-1. Conclusion: The identified ligands inhibit LRH-1 transcriptional activity, diminishing expression of the receptor's target genes. Significance: LRH-1 inhibitors could be used for analyses of the receptor's biological mechanisms and for development of cancer therapeutics.