Fig. 4. P7170 suppresses growth of fulvestrant-resistant T47D/FR tumors.
A) Mice bearing T47D/FR xenografts were treated with fulvestrant since the time of cell implantation. When tumors reached ~200 mm3, were randomized to vehicle or 15 mg/kg/d P7170 (both with continued fulvestrant). Tumor volumes were calculated relative to baseline volume of individual mice, and mean % baseline volumes + SEM are shown. Tumor volumes were analyzed as in Fig. 3A. Mixed modeling revealed that tumor volumes significantly changed over time (p<0.0001). While treatment did not have an independent effect, significant interaction between treatment and time indicated that the effects of P7170 treatment varied over time (p<0.0001). *p<0.05, **p<0.01 compared to vehicle control at each time point. B) Lysates from tumors harvested after 3 days of treatment were analyzed by immunoblot using the indicated antibodies. C-D) Quantification of fractions of Ki67+ and TUNEL+ cells in tumors harvested after 6 weeks of treatment. Horizontal bars indicate median values within each treatment group. Ki67 and TUNEL scores were compared by t-test between groups.