Fig. 2

The impact of T6I-29–1 A on the proliferation and ER target gene expression of Y537S ESR1 mutant breast cancer cells. All drug treatments indicated are 1 µM drug in the presence of 1 nM E2. A) T47D Y537S ESR1 and B) MCF7 Y537S ESR1 breast cancer cell proliferation. Cells were treated for 13 or 5 days, respectively, replenishing treatment conditions every 3–4 days until E2-only wells were confluent and experiments were concluded. Graphs represent the mean of three biological replicates, with three technical replicates/each. Data is normalized to E2 treatment, error bars are s.d. Statistical analysis was performed using Anova with Tukey post-hoc test. C-F) RT-qPCR in T47D Y537S ESR1 and G-J) MCF7 Y537S ESR1 cells. Cells were treated for 6 h as indicated, before harvest and analysis. Representative data are the mean of three replicates ± s.d. and error bars show s.d. Significance determined by one-way Anova test with tukey post-hoc where *p < 0.05, **p < 0.005, ***p < 0.0005, and ****p < 0.00005