High-affinity Binding Sites for Estrogen Receptor α in the p21WAF1/CIP1 Promoter Region in Breast Cancer MCF-7 Cells
10.12007/j.issn.0258-4646.2017.08.002
- VernacularTitle:乳腺癌MCF-7细胞p21WAF1/CIP1启动子区雌激素受体α的高功能结合位点
- Author:
Dan ZOU
1
;
Xiuyan FENG
;
Weiqiang ZHOU
Author Information
1. 沈阳医学院病理生理学教研室
- Keywords:
breast cancer;
MCF-7 cell;
p21WAF1/CIP1;
estrogen receptor α;
suberoylanilide hydroxamic acid;
leptin
- From:
Journal of China Medical University
2017;46(8):677-680,685
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the specific sites that estrogen receptor (ER)α could be recruited to in the p21WAF1/CIP1 promoter region to regulate its transcriptional activity in MCF-7 cells,and to clarify the molecular mechanism of suberoylanilide hydroxamic acid (SAHA) and leptin in the regulation of p21WAFI/CIP1 promoter function.Methods MCF-7 cells were starved by culturing them in fetal calf serum-free medium for 24 hours,and then treated with 20 μmol/L of 0.88 μL SAHA (SAHA group) or 0.625 nmol/L of 10 μL leptin (leptin group) for 24 hours,or cultured in complete RPMI-1640 medium (control group).Cell lysates were incubated with anti-ERα antibody for ChIP analysis.The relative expression levels of DNA fragments,ranging from the TSS to upstream of the p21WAF1/CIP1 promoter region (+2 to-4 000 bp),that bound the antibody were detected by real-time PCR.Results In the control group,the relative expression levels of f1,f2,and f8 DNA fragments that bound the antiERα antibody were two-fold higher than the relative expression of the f9 fragment (P ＜ 0.01).In the SAHA and leptin groups,the relative expression of f1 to f10 DNA fragment that bound anti-ERα antibody was significantly lower than that of the control.The binding affinity of ERα for the f8 fragment was the lowest (P ＜ 0.01) in the SAHA group,and it was significantly lower than that in the leptin group (P ＜ 0.01).Conclusion ERα could be recruited to the p21WAFI/CIP1 promoter via signaling pathways activated during the proliferation of breast cancer MCF-7 cells.Moreover,the DNA fragment ranging from-2 800 to-3 200 bp upstream of the p21 WAF1/CIP1 promoter is the target functional region for high-affinity binding with ERα.
