Figure 2. Melatonin suppressed HCC cell migration and invasion by inhibiting EMT.

(A) The migration abilities of Huh7 and HepG2 cells treated in the presence or absence of melatonin for 24 hr were compared using a transwell assay. Melatonin significantly reduced the migratory ability in the indicated cell lines. The quantitative cell migration assay results are shown in (B). p < 0.01 (**). (C) Invasion assays were performed using Matrigel-coated polyethylene terephthalate membrane inserts. Five different fields (200× magnification) were imaged to quantify the numbers of migrating or invading cells. The quantitative cell invasion assay results are shown in (D). p < 0.001 (***). (E) Western blotting analysis of the expression of EMT-related proteins in the indicated cells treated with either melatonin or vehicle. β-actin served as an internal control. Melatonin significantly reduced the expression levels of EMT-related proteins in Huh7 and HepG2 cells. The quantitative western blotting results are shown in (F) p < 0.05 (*), p < 0.01 (**), p < 0.001 (***).