Fig. 6

Treatment with SB-699551 inhibits the growth of human breast tumor xenografts in vivo. a Twenty-five thousand HCC1954 breast tumor cells were injected into the mammary fat pad of NOD/SCID mice. After four weeks mice bearing tumor xenografts that had reached a volume between 50 and 100 mm³ were randomized into four treatment arms comprising either 13 or 18 mice. b Tumor volume was monitored every four days with digital calipers and the mean xenograft volume +/− the SEM was plotted over the course of 18 days. c The ratio of the final tumor xenograft volume at endpoint compared to their starting volume was calculated for each individual xenograft-bearing mouse. d The mean difference in tumor growth was analyzed for statistical significance using a one-way ANOVA and post-hoc Tukey’s tests [**** p < 0.0001; *** p = 0.0005]. e Representative sections of xenografts stained with hematoxylin and eosin. The red arrows indicate areas of the xenografts with low tumor cell density and the green arrows indicate tumor cells with shrunken, pyknotic nuclei. f TUNEL staining of xenograft sections. The DAPI channel (blue) marks nuclei and the FITC channel (green) marks the FITC-labeled nicked DNA of apoptotic cells. The scale bar represents 100 μm