Brilanestrant (ARN-810) (Synonyms: GDC-0810, RG-6046)

Cell experiment:

MCF-7 cells are adjusted to a concentration of 40000 cells per mL in RPMI containing 10% FBS and 20 mM HEPES. Then 16 μL of the cell suspension (640 cells) is added to each well of a 384-well plate, and the cells are incubated overnight to allow the cells to adhere. The following day a 10-point, serial 1:5 dilution of each compound is added to the cells in 16 μL at a final concentration ranging from 10 to 0.000005 μM. After 5 days' compound exposure, 16 μL of CellTiter-GLo is added to the cells, and the relative luminescence units of each well are determined. CellTiter-GLo added to 32 μL of medium without cells is used to obtain a background value. The percent viability of each sample is determined as follows: (RLU sample-RLU background/RLU untreated cells-RLU background ×100=%viability)

Animal experiment:

Time release pellets containing 0.72 mg 17-β estradiol are subcutaneously implanted into nu/nu mice. MCF-7 cells are grown in RPMI containing 10% FBS at 5% CO2 37°C. Trypsinized cells are pelleted and resuspended in 50% RPMI（serum free）and 50% Matrigel at 1×107 cells/mL. MCF-7 cells are subcutaneously injected (100 μL/animal) on the right flank 2-3 days post pellet implantation. Tumor volume (length × width2/2) is monitored biweekly. When tumors reach an average volume of appr 200 mm3 animals are randomized and treatment is started. Animals are treated with vehicle or compound daily for 4 weeks. Tumor volume and body weight are monitored biweekly throughout the study.

References:

[1]. By Lai, et al. Identification of GDC-0810 (ARN-810), an Orally Bioavailable Selective Estrogen Receptor Degrader (SERD) that Demonstrates Robust Activity in Tamoxifen-Resistant Breast Cancer Xenografts. J Med Chem. 2015 Jun 25;58(12):4888-904.
[2]. Joseph JD, et al. The selective estrogen receptor downregulator GDC-0810 is efficacious in diverse models of ER+ breast cancer. Elife. 2016 Jul 13;5. pii: e15828. doi: 10.7554/eLife.15828