More stable, more estrogenic: the SERM-ERα LBD complex

• Many synthetic selective estrogen receptor mo- dulators (SERMs) have been cocrystallized with the human estrogen receptor α ligand binding domain (ERα LBD). Despite stabilizing the same canonical inactive conformation of the LBD, most SERMs display different ligand-dependent pharmacological profiles. We show here that in-creased partial agonism of SERMs is associated with increased conformational stability of the SERM-LBD complexes, by investigation of dihy-drobenzoxathiin-based SERMs using molecular modelling techniques. Analyses of tamoxifen (TAM) and 4-hydroxytamoxifen (OHT) in complex with the LBD furthermore indicates that the conversion of TAM to OHT increases both the affinity to ERα and the partial agonism of the anti-cancer drug, which provides a plausible ex-planation of the counterintuitive results of TAM therapy.

Keyword

Breast Cancer; Tamoxifen Resistance; Molecular Dynamics Simulations; Dihydrobenzoxathiin; SERM

Publication and Content Type

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