Supplementary Figures from AZD9496: An Oral Estrogen Receptor Inhibitor That Blocks the Growth of ER-Positive and <i>ESR1</i>-Mutant Breast Tumors in Preclinical Models

Supplementary Figure 1 contains a Western blot showing the amount of estrogen receptor remaining after treatment of MCF-7 cells with AZD9496, fulvestrant and estradiol alongside GAPDH protein levels as an internal gel loading control; Supplementary Figure 2 shows the rate of decreased detection by mass spectrometry of an estrogen receptor heavy isotype labelled peptide over time after treatment of cells with AZD9496, fulvestrant and tamoxifen and the calculated half life; Supplementary Figure 3 shows the degradation of estrogen receptor α by AZD9496, fulvestrant and estradiol in the presence of +/- 10 μM proteosomal inhibitor MG132; Supplementary Figure 4 contains a Western blot showing the re-emergence over 48 hours of estrogen receptor α following removal of AZD9496, fulvestrant and estradiol compounds from MCF-7 cells; Supplementary Figure 5 shows a bar chart of the measured estradiol levels in the blood of mice over 42 days after implantation of the mice with estrogen pellets to support growth of the MCF-7 cells as a tumour in mice; Supplementary Figure 6 shows the effects of AZD9496, fulvestrant and tamoxifen on mRNA levels of estrogen receptor regulated genes in vitro and in vivo; Supplementary Figure 7 shows the levels of estrogen receptor α protein remaining in tumours from the HCC1428 LTED model after treatment with AZD9496 and fulvestrant.