Curcumin Inhibits Histone Deacetylase Leading to Cell Cycle Arrest and Apoptosis via Upregulation of p21 in Breast Cancer Cell Lines

ABSTRACT Curcumin was reported to modulate the expression of HDACs 1 and 2. The effect of curcumin on the expression levels of acetylated histones (H3 and H4), acetylated p53, p21, cyclinB1, and Cdk-1 were investigated in breast cancer cell lines MCF-7 and MDA-MB-231, expressing wild-type and mutated p53, respectively. Curcumin increased histone acetylation in both cell lines. Increased p53 acetylation was observed in MCF-7 but not in MDA-MB-231. Upregulation of p21 by curcumin was observed in both cell lines, leading to cell cycle arrest and apoptosis by caspase-9 induction. Curcumin therefore may be regarded as a potent epigenetic regulator in breast cancer.