Curcumin,a potent anti-tumor reagent,is a novel histone deacetylase inhibitor regulating B-NHL cell line Raji proliferation

Aim:To investigate curcumin(diferuloylmethane)induced apoptosis and its mo-lecular mechanism of action in B-NHL cell line Raji cells.Methods:Raji cells werecultured in RPMI-1640 medium and treated with curcumin in different concentra-tions.3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium(MTT)assay wasused to detect growth inhibition and Hoechst 33258 staining was used to detectapoptosis.Immunocytochemistry and Western blot were used to detect the ex-pressions of histone deacetylase 1,3,and 8(HDAC 1,HDAC3,and HDACS)andacetylated histone H4(Ac-histone H4)protein.Results:Curcumin inhibited theproliferation of B-NHL cell line Raji cells with a 36-h IC50value of 24.1±2.0μmol/L.Hoechst 33258 staining showed that curcumin could induce Raji cell apoptosis.The expression levels of HDAC1,HDAC3,and HDAC8 proteins were downregulat-ed following curcumin treatment in Raji cells,whereas Ac-histone H4 protein expres-sion was upregulated after treatment with curcumin.Conclusion:Curcumin,as anew member of the histone deacetylase inhibitors,can inhibit the expression ofclass I HDACs(HDAC1,HDAC3,and HDAC8),and can increase the expressionof Ac-histone H4 in Raji cells.Curcumin plays an important role in regulatingB-NHL cell line Raji cell proliferation and apoptosis.