Synthesis, biological evaluation, structural-activity relationship, and docking study for a series of benzoxepin-derived estrogen receptor modulators.
The estrogen receptors ERalpha and ERbeta are recognized as important pharmaceutical targets for a variety of diseases including osteoporosis and breast cancer. A series of novel benzoxepin-derived compounds are described as potent selective modulators of the human estrogen receptor modulators (SERMs). We report the antiproliferative effects of these compounds on human MCF-7 breast tumor cells. These heterocyclic compounds contain the triarylethylene arrangement as exemplified by tamoxifen, conformationally restrained through the incorporation of the benzoxepin ring system. The compounds demonstrate potency at nanomolar concentrations in antiproliferative assays against an MCF-7 human breast cancer cell line with low cytotoxicity together with low nanomolar binding affinity for the estrogen receptor. The compounds also demonstrate potent antiestrogenic properties in the human uterine Ishikawa cell line. The effect of a number of functional group substitutions on the ER binding properties of the benzoxepin molecular scaffold is examined through a detailed docking and 2D-QSAR computational investigation. The best QSAR model developed for ERalphabeta selectivity yielded R(2) of 0.84 with an RMSE for the training set of 0.30. The predictive quality of the model was Q(2) of 0.72 and RMSE of 0.18 for the test set. One particular compound bearing a 4-fluoro substituent, exhibits 15-fold selectivity for ERbeta and both our docking and QSAR studies converge on the correlation between enhanced lipophilicity and enhanced ERbeta binding for this benzoxepin ring scaffold.
School of Pharmacy and Pharmaceutical Sciences, Centre for Synthesis and Chemical Biology, Trinity College Dublin, Dublin 2, Ireland.
Irene
I
Barrett
Mary J
MJ
Meegan
Rosario B
RB
Hughes
Miriam
M
Carr
Andrew J S
AJ
Knox
Natalia
N
Artemenko
Georgia
G
Golfis
Daniela M
DM
Zisterer
David G
DG
Lloyd
D001584:Benzoxepins / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects; D020847:Estrogen Receptor Modulators / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D047628:Estrogen Receptor alpha / Q000378:metabolism; D047629:Estrogen Receptor beta / Q000378:metabolism; D005260:Female; D006801:Humans; D008958:Models, Molecular; D015394:Molecular Structure; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism
D001584:Benzoxepins; C506487:ESR1 protein, human; D020847:Estrogen Receptor Modulators; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta