Selective Estrogen Receptor Modulators Screening And Activity Assay

Estrogen receptor (ER), which belongs to the nuclear receptor super family, is a kind of important transcriptional regulator and is an essential drug target involving in breast cancer and osteoporosis. More and more research showed that selective estrogen receptor modulators had higher value in clinical application. We use computer virtual screening (VS) and bioassay to discover new selective ER ligands.First, we employed a strategy that combined molecular dynamics (MD) simulation with virtual screening to discover novel ER ligands from a commercial database. The average structure taken from equilibrated stage of ER crystal structure by MD simulation was prepared as the structural basis, and three rounds of VS were subsequently performed. Then 70 candidate compounds were selected for bioassay. We constructed yeast two-hybrid system to screen ligands and determine the capacity of compounds, which was based on the interaction of ER and its activator. As a result, more than 18 potent ligands were discovered. Among them, dual profile was observed in two ligands, as antagonists for ERαand agonists for ERβ; 11 agonists and 5 antagonists were discovered as well, and some of them showed high ER subtype selectivity.We performed cell transfection and luciferase activity assays and MTT assays to check the role of the novel ligands on ER transcriptional activation and antiproliferative potencies on breast cancer cell line. The novel ligands could effects ER transcription and the compounds that showed antagonistic activities on ERβor ERαdisplayed certain antiproliferative activities. We dissected the action of ER antagonist JB042 on suppressing breast caner cells proliferation. By western blot and flow cytometry analysis, we found that treatment with JB042 could down-regualte the expression of cycline D1 indued by estrogen and suppress the progression of G1 to S, subsequently inhibited cell proliferation.