Fig. 3

Fulvestrant-resistant models show variable response to estrogen stimulation and tamoxifen treatment. a, b Relative proliferation of parental and fulvestrant-resistant CAMA-1, MCF7, and HCC1428 cells in estrogen depleted (a) or normal (b) growth media with or without supplementation with 1 nM estradiol (E2) (a) or 100 nM 4-hydroxytamoxifen (4-OHT) (b) for 6 days. Each graph represents combined data (average ± SEM) from two biological experiments with three technical replicates each. Statistical differences were determined using one-way ANOVA with Tukey’s post-hoc test. *** represents p value ≤ 0.0001, ** ≤ 0.001, ns represents no statistical differences. Stars and “ns” in a indicate statistical differences compared to -E2 for each cell model unless indicated otherwise. Stars and “ns” in b indicate statistical differences compared to -4-OHT for each cell model unless indicated otherwise. Data for the ZR-75-1, T47D, and EFM-19 models are shown in Additional file 6