Novel aromatase inhibitors by structure-guided design.
Ghosh, D., Lo, J., Morton, D., Valette, D., Xi, J., Griswold, J., Hubbell, S., Egbuta, C., Jiang, W., An, J., Davies, H.M.(2012) J Med Chem 55: 8464-8476
- PubMed: 22951074 
- DOI: https://doi.org/10.1021/jm300930n
- Primary Citation of Related Structures:  
3S79, 3S7S, 4GL5, 4GL7 - PubMed Abstract: 
Human cytochrome P450 aromatase catalyzes with high specificity the synthesis of estrogens from androgens. Aromatase inhibitors (AIs) such as exemestane, 6-methylideneandrosta-1,4-diene-3,17-dione, are preeminent drugs for the treatment of estrogen-dependent breast cancer. The crystal structure of human placental aromatase has shown an androgen-specific active site. By utilization of the structural data, novel C6-substituted androsta-1,4-diene-3,17-dione inhibitors have been designed. Several of the C6-substituted 2-alkynyloxy compounds inhibit purified placental aromatase with IC(50) values in the nanomolar range. Antiproliferation studies in a MCF-7 breast cancer cell line demonstrate that some of these compounds have EC(50) values better than 1 nM, exceeding that for exemestane. X-ray structures of aromatase complexes of two potent compounds reveal that, per their design, the novel side groups protrude into the opening to the access channel unoccupied in the enzyme-substrate/exemestane complexes. The observed structure-activity relationship is borne out by the X-ray data. Structure-guided design permits utilization of the aromatase-specific interactions for the development of next generation AIs.
Organizational Affiliation: 
Department of Pharmacology, State University of New York Upstate Medical University, Syracuse, NY 13210, USA. ghoshd@upstate.edu