Figure 5. AICAR inhibits growth of SKBR3 xenografts in immunodeficient mice.

Growth of SKBR3 cell xenografts was monitored by measuring dT-Tomato Red fluorescence at 2, 13 and 19 days of tumor growth. Images shown in panel A. are of representative xenografts at 19 days for animals treated with intraperitoneal injections of either AICAR (500 mg/kg, top row) or PBS (control, bottom row). Decreased tumor growth is seen in both the measurements of fluorescence B. and weights of tumors explanted at the conclusion of experiments on day 20 C.. D.SKBR3 xenograft tissues show increased phosphorylation of AMPK and decreased phosphorylation of HER2 (Y1248) / EGFR (Y1173) by immunoblot of tissues explanted from animals one or two hours after treatment with AICAR (500 mg/kg). E. Immunohistochemistry for phosphorylated HER2 (Y1221/Y1222) shows membranous staining in tumors from untreated control animals (top) and decreased staining in tumors from animals two hours after treatment with AICAR (500 mg/kg, bottom).