Fig. 6

Combined treatment of rhein and EGFR inhibitors inhibit tumor growth in xenograft mouse model. a Antitumor efficacy of rhein and erlotinib in the PANC-1 xenograft mouse model. BALB/c mice (n = 6) were treated with DMSO (Control), 10 mg/kg erlotinib, 60 mg/kg rhein, or the combination. Tumor volumes were recorded every 2 days. b Comparison of the final tumor weights in each group after the 28-day treatment of erlotinib and rhein. Numbers in columns indicate the mean tumor weight in each group. c Photographs of tumors in each group. d Western blot analysis of tumor lysates for phosphorylated EGFR (P-EGFR), phosphorylated STAT3 (P-STAT3), BAX and BCL-2. GAPDH was used as loading control. e Body weight of mice. f No histological abnormalities were observed in kidney, liver, lung and heart in the rhein and erlotinib treated groups. Heart, kidney, lung and liver from the four groups were sectioned at 5 μm, and the slides were stained with hematoxylin and eosin (H&E) (n = 5 in each group). All images were captured using an optical microscope with 200× magnification. All images are representative of three independent experiments. The level of significance is indicated by *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001