Figure 6.

PTL inhibits proliferation of colon cancer cells. A, PTL reduces TCF4 levels in colon cancer cells. Colon cancer, SW480, Caco2, and HT29 cells were treated with the indicated doses of PTL for 24 h, and then cells were harvested and analyzed by Western blot analysis. The immunoblots were quantified by densitometry, and the values are given beneath each band. β-cat, β-catenin. B, PTL dose-dependently down-regulates NKD1 mRNA in colon cancer cells. Colon cancer cells were treated with the indicated doses of PTL for 24 h, and then the mRNA levels of NKD1 were evaluated by quantitative real-time PCR. C, PTL inhibits colony formation of colon cancer cells. Cells were treated with the indicated doses of PTL, with medium changes every 3 days until visible colonies formed. Data represent the mean ± S.D. from one experiment. Each experiment was repeated at least three times. **, p < 0.01; ***, p < 0.001; significant relative to vehicle control.