Fig 4. Combined treatment of Vorinostat and ABT significantly increases the inhibition of MDA-MB-231 tumor xenograft growth relative to each agent alone.

a. Effect of the drug combination on tumor development: Differences between the various treatment groups were not detected at first measurements but developed over time. Administration of drugs was initiated two days prior to the injection of the cells on day zero. The combined treatment of vorinostat (200 mg/kg) and ABT-888 (40 mg/kg) had a significant (p<0.02) higher inhibitory effect on the development of tumor growth relative to each agent alone. Values are tumor volumes in mm³ ± SEM. b. Effect of treatments on mice weight: Mice were weighed throughout the experiments. The various drugs did not lead to significant change in weight. c. Samples of mice bearing tumors on last day of the experiment.