Browse
Submit Data
Databases
API
Help

Metabolomics,Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

19 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Chromatin immunoprecipitation of estrogen receptor in human breast cancer cells (MCF-7) treated with estrogen

ABSTRACT: Cross talk between the Estrogen Receptor (ER) and ErbB2/HER-2 pathways have long been implicated in breast cancer aetiology and drug response1, yet no direct connection at a transcriptional level has been shown. We now show that estrogen-ER and tamoxifen-ER complexes directly repress ErbB2 transcription via a cis-regulatory element within the ERBB2 gene. We implicate the Paired Box 2 gene product (Pax2), in a novel role, as a crucial mediator of ER repression of ErbB2 by the anti-cancer drug tamoxifen. We show that Pax2 and the ER co-activator AIB-1/SRC-3 compete for binding and regulation of ErbB2 transcription, the outcome of which determines tamoxifen response in breast cancer cells. The repression of ErbB2 by ER-Pax2 links these two important breast cancer subtypes and suggests that aggressive ErbB2 positive tumours can originate from ER positive luminal tumours by circumventing this repressive mechanism. These data provide mechanistic insight into the molecular basis of endocrine resistance in breast cancer.

ORGANISM(S): Homo sapiens

SUBMITTER: Jason Carroll

PROVIDER: E-TABM-563 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Json Xml

Similar Datasets

Phosphatome profiling of estrogen receptor negative breast cancer

Project description:Purpose: To characterize the expression of phosphatases in estrogen receptor negative breast cancer Little is known about the role of phosphatases in the major estrogen receptor negative breast cancer phenotypes (i.e. those overexpressing ERBB2 and the triple negative). We carried out microarray phosphatome profiling in 41 estrogen receptor negative (ER-) breast cancer patients (as determined by immunohistochemistry (IHC)) containing both ERBB2+ and ERBB2- in order to characterize the differences between these groups by Statistical Analysis of Microarrays (SAM). Our findings point to the importance of the MAPK and PI3K pathways in ER- BCs as some of the most differentially expressed phosphatases (like DUSP4 and DUSP6) share ERK as substrate, or regulate the PI3K pathway (INPP4B, PTEN). These observations are also confirmed by pathway and GSEA analysis. It is shown that both ER- ERBB2+ and triple negative breast cancers have a distinctive pattern of phosphatase RNA expression. Surgical specimens from primary breast cancers that were estrogen receptor negative according to immunohistochemistry

2014-06-30 | E-GEOD-51999 | biostudies-arrayexpress

Genome wide analysis of transcripts regulated by PAX2 and Tamoxifen in MCF-7 cells

Project description:The aim of the study is to understand the role of the transcription factor PAX2 in estrogen receptor positive breast cancer cell line by using GRO-seq. MCF-7-PAX2 stable cells were cultured in full media and treated with doxycycline (50ng/ml) for 16 hours to induce overexpression of PAX2. Then cells were treated with 4-OH-tamoxifen (1μM) for 6 hours. All 4 treatments (Veh, Tam, Dox, DoxTam) were performed in duplicates. After treatments, nuclei were isolated and used for nuclear run-on and subsequent GRO-seq library preparation. Libraries were sequenced and data analysis showed that PAX2 could repress estrogen target genes and induce genes enriched in cytokine (TNF-alpha and INF-gamma) related pathways. When combined with tamoxifen, PAX2 could further repress estrogen target genes to a higher degree, and induce genes enriched in p53 related pathway. Moreover, PAX2 could induce the transcription of some intergenic transcripts (potential enhancers) to activate the transcription of nearby genes with could predict good outcome in estrogen receptor positive breast cancer. Overall our finding suggests that PAX2 could benifit ER positive breast cancer by 1) repressing estrogen target genes, and this effect is enhanced by tamoxifen 2) activating cell death/growth arrest related pathways, which is enhanced by potential enhancer transcription induced by PAX2 itself.

2019-11-06 | GSE139928 | GEO

Phosphatome profiling of estrogen receptor negative breast cancer

2014-06-30 | GSE51999 | GEO

FoxA1 is a critical determinant of Estrogen Receptor function and endocrine response (part I)

Project description:Estrogen Receptor-a (ER) is the key feature in the majority of breast cancers and ER binding to the genome correlates with the Forkhead protein FOXA1 (HNF3a), but mechanistic insight is lacking. We now show that FOXA1 is the defining factor that governs differential ER-chromatin interactions. We show that almost all ER-chromatin interactions and gene expression changes are dependent on the presence of FOXA1 and that FOXA1 dictates genome-wide chromatin accessibility. Furthermore, we show that CTCF is an upstream negative regulator of FOXA1-chromatin interactions. In ER responsive breast cancer cells, the dependency on FOXA1 for tamoxifen-ER activity is absolute and in tamoxifen resistant cells, ER binding occurs independently of ligand, but in a FOXA1 dependent manner. Importantly, expression of FOXA1 in non-breast cancer cells is sufficient to alter ER binding and response to endocrine treatment. As such, FOXA1 is the primary determinant that regulates estrogen-ER activity and endocrine response in breast cancer cells and is sufficient to program ER functionality in non-breast cancer contexts. breast cancer MCF-7 cell lines were treaated in the presence of Estrogen, Estrogen plus Tamoxifen, Tamoxifen or a vehicle. MCF-7 cells were hormone-depleted for 3 d and treated with 100 nM estrogen or 1 microM Tamoxifen for 6 h. There were four biological replicates for each of the four different groups.

2010-11-17 | E-GEOD-25314 | biostudies-arrayexpress

The ets transcription factor ELF5 suppresses the estrogen sensitive phenotype and contributes to antiestrogen resistance in luminal breast cancer. [mouse]

Project description:The ets transcription factor ELF5 specifies the differentiation of mammary progenitor cells to establish the milk-secreting lineage. ER- and poor prognosis basal breast cancers arise from this progenitor cell and these cancers express high levels of Elf5. Knockdown of ELF5 expression in basal breast cancer cell lines, or forced expression in luminal breast cancer cell lines, resulted in reduced cell proliferation. Transcript profiling and chromatin immunoprecipitation revealed that the transcriptional activity of ELF5 specified the gene expression patterns that distinguish basal from luminal breast cancer, including suppression of FOXA1, GATA3 and ER, key estrogen-action genes. Tamoxifen treatment of luminal MCF7 cells upregulated Elf5 expression and cells that acquired resistance to Tamoxifen became dependent on ELF5 for proliferation. ELF5 is a regulator of breast cancer cell proliferation, transcriptionally specifies the basal molecular subtype and is utilised by ER+ breast cancer cells to escape proliferative arrest caused by Tamoxifen. Elf5 was induced via doxycycline treated PyMT mouse tumours, in triplicate

2014-01-13 | E-GEOD-30406 | biostudies-arrayexpress

Estrogen-induced lncRNA, LINC02568, promotes estrogen receptor-positive breast cancer development and drug resistance through both in trans- and in cis-mechanisms

Project description:Estrogen and estrogen receptor (ER) signaling play critical roles in the development of ER-positive breast cancer, and endocrine therapy is the frontline treatment for ER-positive breast cancer patients. However, the primary and acquired resistance to endocrine therapy including tamoxifen and fulvestrant remains as the major challenge in the clinic. Here, we identified an estrogen-induced lncRNA, LINC02568, through transcriptomic analysis, which is highly expressed in ER-positive breast cancer. LINC02568 is functional important in ER-positive breast cancer cell growth in vitro and tumorigenesis in vivo as well as endocrine therapy resistance. Mechanically, we demonstrated that LINC02568 regulates, in trans, estrogen/ERα-induced gene transcriptional activation by sponging miR-1233-5p to stabilize ESR1 mRNA in the cytoplasm. Meanwhile, LINC02568 contributes to tumor-specific pH homeostasis in breast cancer cells by regulating CA12 in cis in the nucleus. The dual functions of LINC02568 together contribute to breast cancer cell growth and tumorigenesis as well as endocrine therapy resistance. Antisense oligonucleotides (ASO) targeting LINC02568 significantly inhibits ER-positive breast cancer cell growth in vitro and tumorigenesis in vivo as well as resensitize tamoxifen-resistant cells to tamoxifen. Furthermore, combination treatment with ASO targeting LINC02568 and tamoxifen exhibits synergistic effect on tumor growth. Taken together, our findings revealed dual mechanisms of LINC02568 in regulating ERα signaling and pH homeostasis in ER-positive breast cancer, and indicated that targeting LINC02568 might represent a potential therapeutic avenue in clinic.

2023-09-13 | GSE217190 | GEO

FoxA1 is a critical determinant of Estrogen Receptor function and endocrine response (part II)

Project description:Estrogen Receptor-a (ER) is the key feature in the majority of breast cancers and ER binding to the genome correlates with the Forkhead protein FOXA1 (HNF3a), but mechanistic insight is lacking. We now show that FOXA1 is the defining factor that governs differential ER-chromatin interactions. We show that almost all ER-chromatin interactions and gene expression changes are dependent on the presence of FOXA1 and that FOXA1 dictates genome-wide chromatin accessibility. Furthermore, we show that CTCF is an upstream negative regulator of FOXA1-chromatin interactions. In ER responsive breast cancer cells, the dependency on FOXA1 for tamoxifen-ER activity is absolute and in tamoxifen resistant cells, ER binding occurs independently of ligand, but in a FOXA1 dependent manner. Importantly, expression of FOXA1 in non-breast cancer cells is sufficient to alter ER binding and response to endocrine treatment. As such, FOXA1 is the primary determinant that regulates estrogen-ER activity and endocrine response in breast cancer cells and is sufficient to program ER functionality in non-breast cancer contexts. FoxA1 silenced breast cancer MCF-7 cell lines or control siRNA in the presence of Estrogen or a vehicle. MCF-7 cells were hormone-depleted for 3 d and treated with 100 nM estrogen for 6 h. There were three biological replicates for each of the four different groups.

2010-11-17 | E-GEOD-25315 | biostudies-arrayexpress

Estrogen Receptor Positive Breast Cancer: Aromatase Inhibitor Response Study

Project description:<p>Highly variable outcomes are observed in patients with estrogen receptor positive (ER+) breast cancer who undergo preoperative estrogen deprivation therapy with aromatase inhibitors (AI). In this study, 46 baseline tumor and normal genomes and 31 baseline tumor/normal exomes of participants selected from two clinical trials of neoadjuvant AI therapy on ER+ breast cancer were sequenced to identify somatic alterations that correlate with response to AI, to screen for therapeutic targets and to elucidate the genetic landscape of ER+ breast cancer. From the same set of patients we later performed deep genomic characterization of a subset of matched primary tumors after four months of AI therapy, generating comprehensive information about the range of changes that occur when ER+ breast cancers are subjected to estrogen deprivation. This data includes whole genome sequence and transcriptome data. To better understand tumor heterogeneity and the evolution of resistance to estrogen-deprivation therapy, a subset of these tumours, along with 38 additional cases were sequenced to greater depth using targeted capture with a gene panel.</p>

| phs000472 | dbGaP

FoxA1 is a critical determinant of Estrogen Receptor function and endocrine response (part II)

2010-11-17 | GSE25315 | GEO

FoxA1 is a critical determinant of Estrogen Receptor function and endocrine response (part I)

2010-11-17 | GSE25314 | GEO