Figure 6.

In vivo anti-tumor efficacy of β-elemene in subcutaneous lung tumor-bearing nude mice model. Mice (n = 11/group) were divided to 3 groups [Con (saline), Low (L, 50 mg/kg) and High (H, 100 mg/kg)], and β-elemene was given at the 10^th day after tumor cells injection by gavages for up to 17 days. (A) The xenografts were assessed by in vivo bioluminescence imaging at the day 1 and the end of the experiments (on day 17). The tumor growth was monitored by injecting luciferin in the mice followed by measuring bioluminescence using IVIS Imaging System. Imaging and quantification of signals were controlled by the acquisition and analysis software living image as described in the Materials and Methods section. Representative images are shown. (B) The photographs of β-elemene or vehicle-treated xenografts derived from nude mice are shown. (C,D) The xenografts were harvested on day 17, and the volume and weight of tumors were measured. (E) At the end of the experiments, xenografted tumors from the high dose and control groups were isolated from individual animals and the corresponding lysates were processed for detecting DNMT1, EZH2, p-Stat3, and PCNA by Western blot. β-actin was used as loading control. The bar graphs represented the tumor weight and volume of mice results of as mean ± SD. *Indicates the significant difference from the untreated control (p < 0.05). (F) The diagram shows that β-elemene inhibits NPC growth through inactivation of Stat3, followed by reduction of DNMT1 and EZH2 expression. The reciprocal communication between DNMT1 and EZH2, the mutual regulatory loops of Stat3 with DNMT1 and EZH2 contribute to the overall responses of β-elemene in this process.