A study on high function binding site of HDAC1 in p21 WAF1/CIP1 promoter region in breast cancer MCF-7 cells / 中国药理学通报

ABSTRACT

Aim Toinvestigatethespecificbinding sites that HDAC1 can be recruited to regulate the tran-scriptional activity of p21 WAF1/CIP1 promoter in the breast cancer MCF-7 cells.Methods ThebreastcancerMCF-7 cells in logarithmic growth phase were starved with FBS free medium for 24 hours,and treated with 20 μmol·L-1 SAHA(S group)or 0. 625 nmol·L-1 Leptin(L group)for 24 hours,and the cells that were cultured in the complete RPMI 1640 medium without any treatment were assigned as control group (B group).The DNA-ChIP was followed the manufactur-er′s protocol for the assay.The cell lysis was prepared and incubated with anti-HDAC1 antibody overnight at 4℃.DNA fragments binding anti-HDAC1 antibody were gathered and purified.The relative expression level of DNA fragments from TSS to the upstream of the p21 WAF1/CIP1 promoter region(+2 ~-4000 bp)bind-ing with antibody was detected by Real-time PCR and analyzedby2-ΔΔCTmethod.Results InBgroup, HDAC1 had high affinity with the f1 and f 8 fragmentsof p21 WAF1/CIP1 promoter compared to the other fragemts,and showed the highest affinity with the f8 fragment.In S group,the binding ability of HDAC1 to the f1 ~f10 fragment of p21 WAF1/CIP1 promoter was sig-nificantly lower than that of the control.The binding activity of HDAC1 to f8 fragment was the lowest,while reversing to reach the peak after leptin treatment.Con-clusions HDAC1canberecruitedtop21WAF1/CIP1pro-moter by the cell proliferation signal during the prolifer-ation of breast cancer MCF-7 cells.The DNA fragment from -2800 to -3200 bp in the upstream of p21 WAF1/CIP1 promoter is the target functional region for the binding with HDAC1 .