Figure 5.

Effect of HSP90 inhibitor AT13387 on UMSCC1 tumor growth. (A) SCID mice were inoculated on day 0 with UMSCC1 cells and then randomized and treated on day 7. Mice received 55 mg/kg AT13387 dissolved in cyclodextrin solution or vehicle alone. Animals were treated through the intraperitoneal route on two consecutive days per week (Monday and Tuesday, indicated by the arrows), for a total of 3 weeks. Mice were euthanized when moribund beginning on day 18, as shown in B by the Kaplan-Meier plot. Student's t test revealed a significant difference (P < .05) in tumor volume between AT13387 treated and control animals during the treatment. (B) Effect of AT13387 on the survival of mice. AT13387 treatment improved the survival of UMSCC1-bearing mice. (C) Vehicle- (n = 2) and AT13387- (n = 3) treated mice were euthanized on day 16, tumors were harvested, and the effect of AT13387 on EGFR, ErbB2, and HSP70 was analyzed by immunoblot analysis. (D) Effect on EGFR expression by AT13387 was further confirmed by immunostaining.