Fig. 1: 20(S)-Rh2E2 suppresses LLC-1 tumor growth and metastasis in LLC-1 bearing C57BL/6 mouse model.
a: Organic synthesis of 20(S)-Rh2E2 and IC50 values of 20(S)/(R)-Rh2E2 on normal lung fibroblasts (CCD19Lu), human normal hepatocytes (LO2) and other cancer cells. Cellular cytotoxicity was measured by MTT assay after 72 h incubation. Representative results were shown as mean ± S.D. from three independent experiments. b, c LLC-1 bearing C57BL/6 mice treated with 20(S)-Rh2E2 [10 or 20 mg/kg/day] or 20(R)-Rh2E2 [10 or 20 mg/kg/day] via IP injection for 21 days. Consecutive treatment of 20(S)-Rh2E2 and 20(R)-Rh2E2 enhanced tumor growth inhibition. Mice tumor volume monitorization and mice body weight are displayed respectively. All data represent mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001 compared to the vehicle-treated group, Student’s t-test. d, e Sub-chronic lethal dose treatment of 20(S)-Rh2E2. C57BL/6 mice were orally administrated with 320 mg/kg of 20(S)-Rh2E2 for 7-days. The survival rate of mice and their body weight were monitored every day. f 20(S)-Rh2E2 and 20(R)-Rh2E2 suppressed the lung tumor metastasis in LLC-1 bearing mice xenograft. The bar chart represents the number of mice with lung metastatic lesions (red area) and the number of mice without metastatic lesion (white area) are shown. *P < 0.05, **P < 0.01, ***P < 0.001, Chi-square test. g, h 20(S)-Rh2E2 and 20(R)-Rh2E2 reduced the metastatic burden area. The percentage of metastatic burden area is displayed in (g). Each dot represents the mice with particular metastatic burden area. Data represent mean ± SEM. *P < 0.05, **P < 0.01, ***P <0.001, Mann–Whitney t-test. h Representative H&E stained lung sections images with metastatic lesions. Infiltrating metastatic cells are visualized in higher magnification. Scale bar = 1 mm (×2.5), scale bar = 100 μm (×10), and scale bar = 20 μm (×40).
