FIGURE 5.

Antitumor efficacy of PI-1840 and bortezomib against human breast cancer MDA-MB-231 xenografts in nude mice. Mice bearing MDA-MB-231 tumors were treated with vehicle (closed squares), PI-1840 (open circles), or bortezomib (filled circles) as described under “Experimental Procedures.” A, representative tumor growth curves form vehicle-, PI-1840-, and bortezomib-treated mice. B, average percent change in tumor volumes from mice treated with vehicle, PI-1840, and bortezomib. There were statistically significant differences between vehicle and PI-1840 in the average percent change in tumor volume on every day of measurement with p values of 0.006, 0.019, 0.009, 0.018, 0.039, and 0.045 on days 3, 5, 7, 10, 12, and 14 of treatment, respectively. In contrast, there were no statistically significant differences between vehicle and bortezomib in the average percent change in volume with p values of 0.243, 0.751, 0.951, 0.842, 0.709, and 0.786 on days 3, 5, 7, 10, 12, and 14 of treatment, respectively.