Abstract: BACKGROUND ＆ AIM: To investigate the effects of NS-398 on the acetylation of histone H3 and P53 and the proliferation of HepG2 cells. MATERIALS AND METHODS: The total protein was extracted from HepG2 cells treated with or without different concentrations of NS-398(0,100，200，300，400 μmol/L)for different times(0,12,24,36, 48 h).Western blot analysis was performed to determine the levels of acetylated histone H3 and acetylated P53.MTT assay was performed to examine the growth inhibition effect of NS-398 on HepG2 cells. RESULTS: NS-398 could inhibit the proliferation of HepG2 cells in a time and dose-dependent manner, with the IC50 at 24 h, 36 h and 48 h of 300 μmol/L,200 μmol/L and 150 μmol/L,respectively.The levels of histone H3 acetylation,P53 expression and P53 acetylation were significantly increased. CONCLUSION: NS-398 functioned as an adeacetylase inhibitor,which could increase the level of acetylated Histone H3，enhance the expression and activity of tumor suppressor P53，and inhibit the proliferation of HepG2 cells

Key words: NS-398, Histone H3, P53, HepG2 cell