Inhibition of PDGFRβ and Abl using nilotinib suppresses growth of LTED cells. The endocrine sensitive cell line MCF7 (A) and the resistant cell line LTED (B) were seeded on 12-well plates and incubated for six days with various concentrations of nilotinib ± E2. Cell proliferation was determined using a Coulter counter. Data are representative of three individual experiments. Error bars express ± SEM of triplicate samples. Two way ANOVA showed a significant difference in cell survival in the LTED cells in the presence or absence of E2 at doses of 1 uM and above P < 0.0001. Abl, Abelson tyrosine kinase; ANOVA, analysis of variance; E2, estradiol; LTED, long term estrogen deprived; PDGFRβ, platelet derived growth factor receptor β; SEM, standard error of the mean.