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. Author manuscript; available in PMC: 2015 Apr 15.
Published in final edited form as: Clin Cancer Res. 2014 Feb 13;20(8):2115–2125. doi: 10.1158/1078-0432.CCR-13-2221

FIGURE 3. Dual Treatment with Vandetanib and Tamoxifen Reduces Xenograft Tumor Growth Greater Than Either Agent Alone.

FIGURE 3

A. Daily gavage with either vandetanib (9 mice) or tamoxifen (8 mice) resulted in a significant reduction in tumor growth in established xenografts compared to vehicle gavage (10 mice). Animals treated with a combination of both vandetanib and tamoxifen (9 mice) had significantly reduced tumor growth compared to either agent alone (p=0.02). Mean relative tumor volume (normalized to the volume at the time of randomization to treatment) is reported with error bars representing the standard deviation. The p values were calculated using the Student’s t-test to compare treatment groups. B. Mice in the dual treatment group were significantly less likely to have progression of the primary tumor site than single agent or control treated animals, p=0.003. The p value was calculated using analysis of variation (ANOVA). C. Protein from xenograft tumors demonstrates that treatment with vandetanib reduces phosphorylation of ERK1/2 and AKT which are downstream signalers in the RET pathway. Treatment with tamoxifen reduced expression of the estrogen response gene GREB-1. Dual treatment (Van + Tam) resulted in decreased activation of RET and ERα pathways. Three tumors were analyzed from each treatment group and representative western blots are shown.