Synergistic effect of ERα on HDAC1 regulatingtranscription of p21WAF1/CIP1 in breast cancer MCF-7 cells / 中国药理学通报

ABSTRACT

Aim To investigate the specific binding sites that histone deacetylases 1(HDAC1) and estrogen receptor α(ERα)can be recruited to regulate the transcriptional activity of p21WAF1/CIP1 promoter in the breast cancer MCF-7 cells, and to clarify the molecular mechanism of suberoylanilide hydroxamic acid(SAHA) and leptin regulating p21WAF1/CIP1 promoter function.Methods The breast cancer MCF-7 cells in logarithmic growth phase were starved with FBS free medium for 24 hours, and treated with 20 μmol·L-1 SAHA(SAHA group) or 0.625 nmol·L-1 leptin(Leptin group) for 24 hours.The cells that were cultured in complete RPMI 1640 medium without any treatment were assigned as control group(Basal group).The cell lysis was prepared and incubated respectively with anti-HDAC1 and anti-ERα antibody by chromatin-immunoprecipitation(ChIP) method overnight at 4℃.The DNA-ChIP was followed the manufacturer′s protocol for the assay.DNA fragments binding anti-HDAC1 and anti-ERα antibody were gathered and purified.The relative expression level of DNA fragments from TSS to the upstream of the p21WAF1/CIP1 promoter region(+2~-4 000 bp) binding with antibody was detected by real-time PCR and analyzed by 2-△△CT method.Results In basal group, HDAC1 and ERα had high affinity with the f1 and f8 fragments of p21WAF1/CIP1 promoter compared to the f4 fragment.In SAHA group, the binding ability of HDAC1 and ERα to the f1 and f8 fragments of p21WAF1/CIP1 promoter was significantly lower than that of the control, while reversing to reach the peak after leptin treatment.Conclusions HDAC1 and ERα can be recruited to p21WAF1/CIP1 promoter by the cell proliferation signal during the proliferation of breast cancer MCF-7 cells.The DNA f1(from 0 to-400 bp) and f8(from-2 800 to-3 200 bp) fragment in the upstream of p21WAF1/CIP1 promoter are the target functional region for the binding with HDAC1and ERα.