Determination of the differential estrogenicity of isoflavonoids by E2-ER-ERE-dependent gene expression in recombinant yeast and MCF-7 human breast cancer cells
Determination of the differential estrogenicity of isoflavonoids by E2-ER-ERE-dependent gene expression in recombinant yeast and MCF-7 human breast cancer cells
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DOI:
10.1016/j.foodchem.2007.11.020
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发表时间:
2008-05-15
期刊:
影响因子:
8.8
通讯作者:
Teng, Shu-Chun
中科院分区:
文献类型:
--
作者:
Lin, Chuan-Chuan;Tsai, Yun-Luen;Teng, Shu-Chun
The use of phytoestrogens-containing natural sources as alternative hormone replacement therapy (HRT) has been a subject of debate for decades. Development of assays to characterize these phytoestrogens is required. In this study, differential estrogenicities of five isoflavonoids found in red clover and soy, including biochanin A, daidzein, formononetin, genistein and glycitein were examined in a yeast-based screen system with a classical palindromic estrogen response element (ERE)-ADE2 reporter and in a MCF-7 cell culture system with mRNA levels of ER-dependent genes compared. In a yeast-based assay, five isoflavonoids showed various extents of estrogenic potencies. A collection of primary estrogen receptor (ER)-regulated genes by estradiol (E-2), including hTERT, c-MYC, BCL2 and Ha-ras (oncogenic) and quinone reductase (QR), human complement 3 (C3) and COX7RP (non-oncogenic) were selected as marker genes for a MCF-7 cell-based endogenous gene expression assay. The results indicated that the mRNA levels of these E-2-ER-ERE-dependent marker genes were regulated differentially by five isoflavonoids, leading to distinct expression patterns, which are also significantly different from that of E-2. Moreover, the anti-estrogenic effects of biochanin A and formononetin on E-2-induced transcriptions of marker genes in MCF-7 cells were also displayed. Taken together, these results are significant for these naturally occurring isoflavonoids regarding the issues of safety and efficacy. (C) 2007 Elsevier Ltd. All rights reserved.