Targeting cholesterol biosynthesis pathway suppresses CRC liver metastasis. A-C, The effect of Betulin on expression of nuclear form of SREBP2 (n-SREBP2) and precursor of SREBP2 (pre-SREBP2) (A), total cholesterol level (B, C) and colony formation (D-F) in HT29 and SW620 cells. Representative results from three biological independent experiments are shown. Data are shown as mean ± SD of triplicate experiments (B-E). G-K, A schematic diagram showing the experiment design (G). HT29 cells were injected into liver of mice. Three days after injection, mice were administered with betulin or simvastatin as indicated. At the end of the experiment, liver metastases were taken photos (H) and were dissected for assessing tumor volume (I), and total cholesterol levels were determined in serums (J) and in liver metastases (K). Data are shown as mean ± SEM (n = 5, I-K). Significance was determined by one-way ANOVA (B-E, I-K). *P < 0.05, **P < 0.01, ***P < 0.001. ns, not significant.