Ontology highlight
ABSTRACT:
OTHER RELATED OMICS DATASETS IN: E-GEOD-22533
PROVIDER: PRJNA167152 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:This SuperSeries is composed of the following subset Series: GSE22533: Breast cancer cells resistant to hormone deprivation maintain an estrogen receptor alpha-dependent, E2F-directed transcriptional program GSE27300: Estrogen-independent genomic ER binding analysis Refer to individual Series
2012-05-14 | E-GEOD-37955 | biostudies-arrayexpress
Project description:The estrogen receptor alpha (ERa) drives the growth of two-thirds of all breast cancers. Endocrine therapy impinges on estrogen-induced ERa activation to block tumor growth. However, half of ERa-positive breast cancers are tolerant or acquire endocrine therapy resistance. Here we demonstrate that breast cancer cells undergo genome-wide reprogramming of their chromatin landscape, defined by epigenomic maps and chromatin openness, as they acquire resistance to endocrine therapy. This reveals a role for the Notch pathway while excluding classical ERa signaling. In agreement, blocking Notch signaling, using gamma-secretase inhibitors, or targeting its downstream gene PBX1 abrogates growth of endocrine therapy-resistant breast cancer cells. Moreover Notch signaling through PBX1 directs a transcriptional program predictive of tumor outcome and endocrine therapy response.
2013-05-01 | GSE37323 | GEO
Project description:The estrogen receptor alpha (ERa) drives the growth of two-thirds of all breast cancers. Endocrine therapy impinges on estrogen-induced ERa activation to block tumor growth. However, half of ERa-positive breast cancers are tolerant or acquire endocrine therapy resistance. Here we demonstrate that breast cancer cells undergo genome-wide reprogramming of their chromatin landscape, defined by epigenomic maps and chromatin openness, as they acquire resistance to endocrine therapy. This reveals a role for the Notch pathway while excluding classical ERa signaling. In agreement, blocking Notch signaling, using gamma-secretase inhibitors, or targeting its downstream gene PBX1 abrogates growth of endocrine therapy-resistant breast cancer cells. Moreover Notch signaling through PBX1 directs a transcriptional program predictive of tumor outcome and endocrine therapy response. Comparing histone modifications (H3K4me2 and H3K36me3), chromatin openness (FAIRE) and PBX1 binding between endocrine therapy sensitive MCF7 and resistant MCF7-LTED cells.
2013-05-01 | E-GEOD-37323 | biostudies-arrayexpress
Project description:Estrogen deprivation using aromatase inhibitors is currently the standard of care for patients with estrogen-receptor (ER)-positive breast cancer. Unfortunately, prolonged estrogen deprivation leads to drug resistance (i.e. hormone-independent growth). We therefore used DNA microarray analysis to study the gene expression profiles of wild-type MCF-7 cells (which are sensitive to antihormone therapy) and long-term estrogen deprived MCF-7:5C and MCF-7:2A breast cancer cells (which are resistance to estrogen-deprivation; aromatase inhibitor resistant). Transcriptional profiling of wild-type MCF-7 cells and estrogen deprived MCF-7:5C and MCF-7:2A cells was performed using Affymetrix Human Genome U133 Plus 2.0 Array. Keywords: breast cancer cells, estrogen
2008-03-19 | GSE10879 | GEO
Project description:Aromatase inhibitors are first-line postmenopausal agents for estrogen receptor alpha (ERa)-positive breast cancer. However, there is considerable response heterogeneity and women frequently relapse. Estrogen deprivation does not completely arrest ERa activity, and transactivation of the unliganded receptor may continue through cross-talk with growth factor pathways. In contrast with aromatase inhibitors, the selective ER downregulator fulvestrant also abrogates ligand-independent ERa activity. The benefit of fulvestrant as an alternative, combination, or sequential therapy to aromatase inhibitor has been reported, but molecular mechanisms underpinning its relative efficacy remain unclear and biomarkers for patient selection are lacking. This study demonstrates, for the first time, that the overall transcriptional response to fulvestrant is of greater magnitude than estrogen deprivation, consistent with its clinical efficacy and more complete blockade of estrogenic signaling. Using a robust integrative approach, we identify a subset of genes differentially affected by fulvestrant that comprises distinct biologic networks, correlates with antiproliferative response, and has potential utility as predictive biomarkers for fulvestrant. Global gene expression profiles from ERα-positive breast carcinomas before and during presurgical treatment with fulvestrant (n = 38) or anastrozole (n = 81), and corresponding in vitro models, were compared. Transcripts responding differently to fulvestrant and estrogen deprivation were identified and integrated using Gene Ontology, pathway and network analyses to evaluate their potential significance. --------------------------------- This represents the data for fulvestrant only
2015-08-07 | E-GEOD-71791 | biostudies-arrayexpress
Project description:Aromatase inhibitors are first-line postmenopausal agents for estrogen receptor alpha (ERa)-positive breast cancer. However, there is considerable response heterogeneity and women frequently relapse. Estrogen deprivation does not completely arrest ERa activity, and transactivation of the unliganded receptor may continue through cross-talk with growth factor pathways. In contrast with aromatase inhibitors, the selective ER downregulator fulvestrant also abrogates ligand-independent ERa activity. The benefit of fulvestrant as an alternative, combination, or sequential therapy to aromatase inhibitor has been reported, but molecular mechanisms underpinning its relative efficacy remain unclear and biomarkers for patient selection are lacking. This study demonstrates, for the first time, that the overall transcriptional response to fulvestrant is of greater magnitude than estrogen deprivation, consistent with its clinical efficacy and more complete blockade of estrogenic signaling. Using a robust integrative approach, we identify a subset of genes differentially affected by fulvestrant that comprises distinct biologic networks, correlates with antiproliferative response, and has potential utility as predictive biomarkers for fulvestrant.
2015-08-07 | GSE71791 | GEO
Project description:Breast Cancer (BC) is one of the main causes of cancer-related death in women. The most widespread BC subtype (75%) is the hormone-dependent, characterized by high expression of Estrogen Receptor Alpha (ERa). ERa exerts its oncogenic activity through the interaction with different co-regulators, carrying out a direct control on gene transcription and thus being the target of specific anticancer therapies. Despite the efficiency of these drugs, 30% of patients develop de novo or acquired resistance mechanisms, caused by alternative mechanisms that bypass antiestrogenic effects determining the onset of relapse. In order to identify new and potentially drugable Era molecular partners, essential genes for BC progression in luminal cell lines assessed by CRISPR-cas assay were compared to ERa interactome, dropping our focus on the tyrosine-protein kinase BAZ1B. BAZ1B is an essential component of the WICH complex and plays a crucial role in chromatin remodelling acting also as transcription regulator. In order to characterize the functional role of BAZ1B in luminal BC, we first employed a TCGA analysis that showed higher expression of BAZ1B in luminal BC associated with a worst overall survival and progression free survival of patient affected by this disease. A transcriptome profiling after BAZ1B silencing was performed in MCF-7 cells, highlighting an impact of modulated genes in key BC pathways including the estrogen signalling. BAZ1B silencing showed also an effect on cell growth, inhibiting cell proliferation and increasing apoptosis activation mechanisms promoted by the loss of ERa protein expression coupled to a reduction of the receptor transactivation activity. Interesting, these effects were confirmed also in antiestrogen (Tamoxifen and Fulvestrant) resistant BC cell models that retain ERa expression, suggesting BAZ1B as a novel and potentially exploitable therapeutic target in the treatment of both hormone dependent and resistant mammary tumours.
2022-07-25 | E-MTAB-11142 | biostudies-arrayexpress
Project description:Poly (ADP-ribose) polymerase-1 (PARP-1), a multifunctional chromatin-modulating protein, has gained considerable attention as a target for therapeutic inhibitors in breast cancers. Accumulating evidence suggests a pathological role for PARP-1 in breast cancer through its effects on the transcription of tumor-related genes. Here we report the role of PARP-1 in estrogen-dependent transcription in estrogen receptor alpha (ERα)-positive breast cancers. Global nuclear run-on and sequencing (GRO-seq) analyses suggest that PARP-1 controls the expression of estrogen-regulated genes in ER-positive (ER+) MCF-7 breast cancer cells. Further, ChIP-seq analyses revealed that PARP-1 directly regulates the ligand-dependent binding of ERa and FoxA1 to a subset of its genomic binding sites. Finally, we uncovered that the expression levels of the PARP-1 and estrogen coregulated gene set are enriched in luminal molecular-subtype of breast tumors and high PARP-1 expression in ER+ cases correlates with poor survival. Additionally, treatment with PARP-1 selective inhibitors showed attenuated estrogen-dependent growth of ER+ breast cancer cells. Taken together, the current study suggests that PARP-1 regulates critical molecular pathways that underlie proliferation of ER+ breast cancer cells.
2021-10-13 | GSE166168 | GEO
Project description:The estrogen receptor a (ERa) is a ligand-regulated transcription factor. However, a wide variety of other extracellular signals can activate ERa in the absence of estrogen. The impact of these alternate modes of activation on gene expression profiles has not been characterized. We show that estrogen, growth factors and cAMP elicit surprisingly distinct ERa-dependent transcriptional responses in human MCF7 breast cancer cells. In response to growth factors and cAMP, ERa primarily activates and represses genes, respectively. The combined treatments with the antiestrogen tamoxifen and cAMP or growth factors regulate yet other sets of genes. In many cases, tamoxifen is perverted to an agonist, potentially mimicking what is happening in certain tamoxifen-resistant breast tumors and emphasizing the importance of the cellular signaling environment. Using a computational analysis, we predicted that a Hox protein might be involved in mediating such combinatorial effects, and then confirmed it experimentally. Although both tamoxifen and cAMP block the proliferation of MCF7 cells, their combined application stimulates it, and this can be blocked with a dominant-negative Hox mutant. Thus, the activating signal dictates both target gene selection and regulation by ERa, and this has consequences on global gene expression patterns that may be relevant to understanding the progression of ERa-dependent carcinomas. Keywords: treatment response 10 treatment conditions (3 biological replicates for each, totalling 30 individual samples), of which 3 were untreated controls. Each replicate was hybridized to a separate chip, totalling 27 cDNA slides representing 9 unique conditions.
2008-05-22 | E-GEOD-10466 | biostudies-arrayexpress
Project description:The estrogen receptor a (ERa) is a ligand-regulated transcription factor. However, a wide variety of other extracellular signals can activate ERa in the absence of estrogen. The impact of these alternate modes of activation on gene expression profiles has not been characterized. We show that estrogen, growth factors and cAMP elicit surprisingly distinct ERa-dependent transcriptional responses in human MCF7 breast cancer cells. In response to growth factors and cAMP, ERa primarily activates and represses genes, respectively. The combined treatments with the antiestrogen tamoxifen and cAMP or growth factors regulate yet other sets of genes. In many cases, tamoxifen is perverted to an agonist, potentially mimicking what is happening in certain tamoxifen-resistant breast tumors and emphasizing the importance of the cellular signaling environment. Using a computational analysis, we predicted that a Hox protein might be involved in mediating such combinatorial effects, and then confirmed it experimentally. Although both tamoxifen and cAMP block the proliferation of MCF7 cells, their combined application stimulates it, and this can be blocked with a dominant-negative Hox mutant. Thus, the activating signal dictates both target gene selection and regulation by ERa, and this has consequences on global gene expression patterns that may be relevant to understanding the progression of ERa-dependent carcinomas. Keywords: treatment response
2008-05-22 | GSE10466 | GEO