Transcriptional Activation of E2F1 Gene Expression by 17 -Estradiol in MCF-7 Cells Is Regulated by NF-Y-Sp1/Estrogen Receptor Interactions

1999 ◽  
Vol 13 (8) ◽  
pp. 1373-1387 ◽  
Author(s):  
W. Wang
Keyword(s):  
Gene Expression ◽  
Estrogen Receptor ◽  
Transcriptional Activation ◽  
Receptor Interactions ◽  
Mcf 7

scholarly journals Transcriptional Activation of E2F1 Gene Expression by 17β-Estradiol in MCF-7 Cells Is Regulated by NF-Y-Sp1/Estrogen Receptor Interactions

1999 ◽  
Vol 13 (8) ◽  
pp. 1373-1387 ◽  
Author(s):  
Weili Wang ◽  
Lian Dong ◽  
Brad Saville ◽  
Stephen Safe
Keyword(s):  
Gene Expression ◽  
Estrogen Receptor ◽  
Dna Binding ◽  
Transcriptional Activation ◽  
Gene Promoter ◽  
Proximal Region ◽  
Mobility Shift ◽  
Protein Levels ◽  
17Β Estradiol ◽  
Mcf 7

Abstract 17β-Estradiol (E2) stimulated proliferation and DNA synthesis in MCF-7 human breast cancer cells, and this was accompanied by induction of E2F1 mRNA and protein levels. Analysis of the E2F1 gene promoter showed that the −146 to− 54 region was required for E2-responsiveness in transient transfection assays, and subsequent deletion/mutation analysis showed that a single upstream GC-rich and two downstream CCAAT-binding sites were required for transactivation by E2. Gel mobility shift assays with multiple oligonucleotides and protein antibodies (for supershifts) showed that the −146 to −54 region of the E2F1 gene promoter bound Sp1 and NF-Y proteins in MCF-7 cells. The estrogen receptor (ER) protein enhanced Sp1 interactions with upstream GC-rich sites, and interactions of ER, Sp1, and ER/Sp1 with downstream DNA bound-NF-Y was investigated by kinetic analysis for protein-DNA binding (on- and off-rates), coimmunoprecipitation, and pulldown assays using wild-type and truncated glutathione S-transferase (GST)-Sp1 chimeric proteins. The results showed that Sp1 protein enhanced the Bmax of NF-Y-DNA binding by more than 5-fold (on-rate); in addition, the Sp1-enhanced NF-Y-DNA complex was further stabilized by coincubation with ER and the rate of dissociation (t1/2) was decreased by approximately 50%. Sp1 antibodies immunoprecipitated [35S]NF-YA after coincubation with unlabeled Sp1 protein. Thus, transcriptional activation of E2F1 gene expression in MCF-7 cells by E2 is regulated by multiprotein ER/Sp1-NF-Y interactions at GC-rich and two CCAAT elements in the proximal region of the E2F1 gene promoter. This represents a unique trans-acting protein complex in which ligand-dependent transactivation by the ER is independent of direct ER interactions with promoter elements.

scholarly journals Transcriptional Activation of Deoxyribonucleic Acid Polymerase α Gene Expression in MCF-7 Cells by 17β-Estradiol*

Endocrinology ◽  
2001 ◽  
Vol 142 (3) ◽  
pp. 1000-1008 ◽  
Author(s):  
Ismael Samudio ◽  
Carrie Vyhlidal ◽  
Fan Wang ◽  
Matthew Stoner ◽  
Ichen Chen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcriptional Activation ◽  
Deoxyribonucleic Acid ◽  
17Β Estradiol ◽  
Mcf 7

scholarly journals Regulation of estrogen receptor-? gene expression by 1,25-dihydroxyvitamin D in MCF-7 cells

1999 ◽  
Vol 75 (4) ◽  
pp. 640-651 ◽  
Author(s):  
Adriana Stoica ◽  
Miguel Saceda ◽  
Amina Fakhro ◽  
Harrison B. Solomon ◽  
Bradley D. Fenster ◽  
...  
Keyword(s):  
Gene Expression ◽  
Estrogen Receptor ◽  
Receptor Gene ◽  
Estrogen Receptor Gene ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Receptor Gene Expression ◽  
Mcf 7

scholarly journals Transcriptional Activation of Insulin-Like Growth Factor-Binding Protein-4 by 17β-Estradiol in MCF-7 Cells: Role of Estrogen Receptor-Sp1 Complexes*

Endocrinology ◽  
1999 ◽  
Vol 140 (6) ◽  
pp. 2501-2508 ◽  
Author(s):  
Chunhua Qin ◽  
Pomila Singh ◽  
Stephen Safe
Keyword(s):  
Gene Expression ◽  
Estrogen Receptor ◽  
Growth Factor ◽  
Binding Protein ◽  
Gene Promoter ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Human Estrogen Receptor ◽  
17Β Estradiol ◽  
Mcf 7

Abstract Insulin-like growth factor-binding protein-4 (IGFBP-4) is expressed in MCF-7 human breast cancer cells, and treatment of these cells with 17β-estradiol (E2) resulted in induction of IGFBP-4 gene expression (>3-fold) and protein secretion (>6-fold). To identify genomic sequences associated with E2 responsiveness, the 5′-promoter region (−1214 to +18) of the IGFBP-4 gene was cloned into a vector upstream from the firefly luciferase reporter gene, and E2 induced a 10-fold increase in luciferase activity in MCF-7 cells transiently transfected with this construct. Deletion analysis of this region of the IGFBP-4 gene promoter identified two GC-rich sequences at −559 to −553 and −72 to −64 that were important for E2-induced trans-activation. Gel mobility shift assays using 32P-labeled −569 to −540 and −83 to −54 oligonucleotides from the IGFBP-4 gene promoter showed that Sp1 protein bound these oligonucleotides to form a retarded band, and the intensity of the band was competitively decreased after coincubation with unlabeled IGFBP-4-derived and consensus Sp1 oligonucleotides. Mutation of the GC-rich sites within these sequences resulted in loss of the retarded band formation. Wild-type human estrogen receptor did not bind directly to the IGFBP-4 oligonucleotides; however, human estrogen receptor enhanced Sp1-DNA binding in a concentration-dependent manner. The results of this study demonstrate that at least two GC-rich sequences at −559 to −553 and− 72 to −64 are required for induction of IGFBP-4 gene expression by E2 in MCF-7 cells.

scholarly journals Activation of adenosine deaminase in MCF-7 cells through IGF-estrogen receptor alpha crosstalk

2001 ◽  
Vol 26 (3) ◽  
pp. 217-228 ◽  
Author(s):  
W Xie ◽  
R Duan ◽  
S Safe
Keyword(s):  
Gene Expression ◽  
Estrogen Receptor ◽  
Adenosine Deaminase ◽  
Estrogen Receptor Alpha ◽  
Gene Promoter ◽  
Mapk Signaling ◽  
Dominant Negative ◽  
Mitogen Activated Protein Kinase ◽  
Receptor Alpha ◽  
Mcf 7

Adenosine deaminase (ADA) regulates cellular levels of adenosine and deoxyadenosine, and 17beta-estradiol (E(2)) induces ADA mRNA in MCF-7 human breast cancer cells. IGF-I also induces ADA gene expression in these cells, and induction of this response through IGF activation of estrogen receptor alpha (ERalpha) was further investigated. IGF and other polypeptide growth factors induce reporter gene expression in MCF-7 cells cotransfected with ERalpha expression plasmid and pADA211, a construct containing the -211 to +11 region of the ADA gene promoter which is required for high basal and E(2)-inducible activity. Deletion analysis of this promoter demonstrates that IGF activates ERalpha/Sp1 interactions with multiple GC-rich sites in the promoter and this response is abrogated in cells transfected with ERalpha containing mutations at Ser(118) or Ser(163). IGF induces both MAPK (mitogen-activated protein kinase) and PI3-K (phosphatidylinositol-3-kinase) phosphorylation cascades in MCF-7 cells; however, using a series of inhibitors and dominant negative constructs, our results show that induction of ADA by IGF activation of ERalpha/Sp1 is dependent on the MAPK signaling pathway.

scholarly journals Transcriptome profiling reveals bisphenol A alternatives activate estrogen receptor alpha in human breast cancer cells

2017 ◽  
Author(s):  
Robin Mesnage ◽  
Alexia Phedonos ◽  
Matthew Arno ◽  
Sucharitha Balu ◽  
J. Christopher Corton ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Estrogen Receptor ◽  
Human Breast Cancer ◽  
Breast Cancer Cells ◽  
Estrogenic Activity ◽  
Human Breast Cancer Cell ◽  
Human Breast Cancer Cells ◽  
Human Breast ◽  
Mcf 7

AbstractBackgroundPlasticizers with estrogenic activity, such as bisphenol A (BPA), have been reported to have potential adverse health effects in humans. Due to mounting evidence of these health effects and public pressure, BPA is being phased out by the plastics manufacturing industry and replaced by other bisphenol variants in “BPA-free” products.ObjectivesWe have compared estrogenic activity of BPA to 6 bisphenol analogues (bisphenol S, BPS; bisphenol F, BPF; bisphenol AP, BPAP; bisphenol AF, BPAF; bisphenol Z, BPZ; bisphenol B, BPB) in three human breast cancer cell lines.MethodsEstrogenicity was assessed by cell growth in an estrogen receptor (ER)-mediated cell proliferation assay, and by the induction of estrogen response element (ERE)-mediated transcription in a luciferase assay. Gene expression profiles were determined in MCF-7 human breast cancer cells by microarray analysis and confirmed by Illumina-based RNA sequencing.ResultsAll bisphenols showed estrogenic activity in promoting cell growth and inducing ERE-mediated transcription. BPAF was the most potent bisphenol, followed by BPB > BPZ ~ BPA > BPF ~ BPAP > BPS. The addition of ICI 182,780 antagonized the activation of ERs by bisphenols. Data mining of ToxCast high-throughput screening assays confirms our results but also shows divergence in the sensitivities of the assays. The comparison of transcriptome profile alterations resulting from BPA alternatives with an ERα gene expression biomarker further indicates that all BPA alternatives act as ERα agonists in MCF-7 cells. These results were confirmed by RNA sequencing.ConclusionIn conclusion, BPA alternatives are not necessarily less estrogenic in a human breast cancer cell model. Three bisphenols (BPAF, BPB, and BPZ) were more estrogenic than BPA. The relevance of human exposure to BPA alternatives in hormone-dependent breast cancer risk should be investigated.

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