Estrogen Receptor Beta Impacts Hormone-Induced Alternative mRNA Splicing in Breast Cancer Cells
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE64590 | GEO | 2015/09/01
SECONDARY ACCESSION(S): PRJNA271362
REPOSITORIES: GEO
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Project description:Estrogens play an important role in breast cancer (BC) development and progression, where the two isoforms of the estrogen receptor (ER? and ER?) are generally co-expressed and mediate the effects of these hormones in cancer cells. ER? has been suggested to exert an antagonist role toward the oncogenic activities of ER?, and for this reason it is considered an oncosuppressor. As clinical evidence regarding a prognostic role for this receptor subtype in hormone-responsive BC is still limited and conflicting, more knowledge is required on the biological functions of ER? in cancer cells. We described previously the ER? and ER? interactomes of BC cells, identifying specific and distinct patterns of protein interactions for the two receptors. In particular, we identified factors involved in mRNA splicing and maturation as important components of both ER? and ER? pathways. Guided by these findings, we investigated here in depth the differences in the early transcriptional events and RNA splicing patterns induced in ER? vs ER?+ER? cells, by expressing ER? in ER?+ human BC MCF-7 cells. High-throughput mRNA sequencing was then performed in both cell lines after stimulation with 17b-estradiol, and the results obtained were compared. We investigated here in depth the differences in the early transcriptional events and RNA splicing patterns induced in ER? vs ER?+ER? cells, by expressing ER? in ER?+ human BC MCF-7 cells. High-throughput mRNA sequencing was then performed in both cell lines after stimulation with 17b-estradiol, and the results obtained were compared.
2015-09-01 | E-GEOD-64590 | biostudies-arrayexpress
Project description:Estrogen Receptor subtypes (ERα and ERβ) are transcription factors sharing similar structure, however, they often perform opposite roles in breast cancer’s cell proliferation and tumor progression. Besides the well-characterized genomic actions of ERs upon ligand binding, rapid non-genomic cytoplasmic changes together with the recently discovered ligand-free action of ERs are emerging as key regulators of tumorigenesis. The identification of cytoplasmic interaction partners of unliganded ERα and ERβ may help characterize the molecular basis of the extra-nuclear mechanism of action of these receptors, revealing novel mechanisms to explain their role in breast cancer response or resistance to endocrine therapy. To this aim, in this study, cytoplasmic extracts from stably expressing TAP-ERα and -ERβ MCF-7 cell clones were subjected to interaction proteomics in the absence of estrogen stimulation, leading to the identification of 84 and 142 proteins associated with unliganded ERα and ERβ, respectively. Functional analyses of ER subtype-specific interactomes revealed significant differences in the molecular pathways associated to each receptor in the cytoplasm. This work reports the first identification of the unliganded ERα and ERβ cytoplasmic interactomes in breast cancer cells, providing novel experimental evidence on the non-genomic effects of ERs in the absence of hormonal stimulus.
2015-03-11 | PXD001202 | Pride
Project description:Breast cancer (BC) is the second most common type of cancer in women and one of the leading causes of cancer-related deaths worldwide. BC classification is based on the detection of three main histological markers: estrogen receptor alpha (ERα), progesterone receptor (PR) and the amplification of epidermal growth factor receptor 2 (HER2/neu). A specific BC subtype, named triple-negative BC (TNBC), lacks the aforementioned markers but a fraction of them express the estrogen receptor beta (ERβ). To investigate the functional role of ERβ in these tumors, interaction proteomics coupled to mass spectrometry (MS) was applied to deeply characterize the nuclear interactors partners in MDA-MD-468 and HCC1806 TNBC cells.
2019-12-03 | PXD014468 | Pride
Project description:Breast cancer (BC) is the most common cancer in women worldwide, and is classified in multiple subtypes, including the so called triple-negative BC (TNBC). This is characterized by lack of estrogen receptor alpha (ERα), progesterone receptor (PR) and epidermal growth factor receptor 2 (HER2/neu), that represent common targets for BC treatment. Their absence limits the number of therapies that may be applied for TNBC treatment, suggesting the need to identify novel therapeutic targets against this disease. Several studies reported that the beta ER subtype (ERβ) is expressed in a sizeable fraction of TNBCs where its presence correlates with improved patient outcome. We evaluated ERβ expression in TNBC tissues by immunohistochemistry using two validated antibodies, demonstrating presence of this protein in 28% of samples. To investigate, in this context, the role of this estrogen receptor in TNBC biology, ERβ-expressing cell lines, representing different TNBC subtypes, were generated. Cellular and functional assays confirmed the antiproliferative activity of ERβ in TNBCs. Interaction proteomics revealed in BC nuclei the presence of several protein complexes associated with this receptor involved in chromatin remodeling, miRNA maturation and mRNA transcription. Transcriptome analyses pointed out tumor subtype-specific signaling pathways deregulation. Interestingly, among these the cholesterol biosynthesis pathway was commonly downregulated in all cell lines tested. Global analyses of ERβ binding to the genome showed its recruitment to regulatory sites of Sterol Regulatory Element-Binding Protein 1 (SREBP1), indicating a direct regulation of this pathway by the receptor. These findings suggest that drugs targeting components of cholesterol biosynthesis pathway may be new potential therapeutic options for TNBC treatment.
2019-12-02 | E-MTAB-8056 | biostudies-arrayexpress
Project description:Breast cancer (BC) is the most common cancer in women worldwide, and is classified in multiple subtypes, including the so called triple-negative BC (TNBC). This is characterized by lack of estrogen receptor alpha (ERα), progesterone receptor (PR) and epidermal growth factor receptor 2 (HER2/neu), that represent common targets for BC treatment. Their absence limits the number of therapies that may be applied for TNBC treatment, suggesting the need to identify novel therapeutic targets against this disease. Several studies reported that the beta ER subtype (ERβ) is expressed in a sizeable fraction of TNBCs where its presence correlates with improved patient outcome. We evaluated ERβ expression in TNBC tissues by immunohistochemistry using two validated antibodies, demonstrating presence of this protein in 28% of samples. To investigate, in this context, the role of this estrogen receptor in TNBC biology, ERβ-expressing cell lines, representing different TNBC subtypes, were generated. Cellular and functional assays confirmed the antiproliferative activity of ERβ in TNBCs. Interaction proteomics revealed in BC nuclei the presence of several protein complexes associated with this receptor involved in chromatin remodeling, miRNA maturation and mRNA transcription. Transcriptome analyses pointed out tumor subtype-specific signaling pathways deregulation. Interestingly, among these the cholesterol biosynthesis pathway was commonly downregulated in all cell lines tested. Global analyses of ERβ binding to the genome showed its recruitment to regulatory sites of Sterol Regulatory Element-Binding Protein 1 (SREBP1), indicating a direct regulation of this pathway by the receptor. These findings suggest that drugs targeting components of cholesterol biosynthesis pathway may be new potential therapeutic options for TNBC treatment.
2019-12-03 | E-MTAB-8055 | biostudies-arrayexpress
Project description:Background: The RNA-binding protein Argonaute 2 (AGO2) is a key effector of RNAsilencing pathways, exerting a pivotal role in microRNA maturation and activity, that in the cell nucleus is able to modulate chromatin remodeling, transcriptional gene regulation and RNA splicing. The Estrogen Receptor beta (ERβ), a member of the nuclear receptor superfamily of trancriptional regulators, is endowed with oncosuppressive activities, antagonizing hormone-induced carcinogenesis and inhibiting growth and oncogenic functions in luminal-like breast cancers (BCs), where its expression correlates with a better prognosis of the disease. Results: Applying interaction proteomics coupled to mass spectrometry (MS) to characterize nuclear factors cooperating with ERβ in gene regulation, we identified AGO2 as a novel partner of ERβ in human BC cells. ERβ-AGO2 association was confirmed in vitro and in vivo both in the nucleus and cytoplasm. ChIP-Seq demonstrated AGO2 association to a large number of ERβ binding sites, and total and nascent RNA-Seq in ERβ+ vs ERβ- cells, and before and after AGO2 knock-down in ERβ+ cells, revealed a widespread involvement of this factor in ERβ-mediated regulation of gene transcription rate and RNA splicing. Moreover, isolation and sequencing by RIP-Seq of ERβ-associated long and small RNAs in the cytoplasm suggested involvement of the nuclear receptor in RISC loading, indicating that it may able to control directly also mRNA translation efficiency and stability. Conclusions: These results demonstrate that AGO2 is a pleiotropic functional partner of ERβ in BC cells, indicating that both factors are endowed with multiple roles in the control of BC cell functions.
2017-09-20 | PXD006280 | Pride
Project description:Triple negative breast cancer (TNBC) is a highly heterogeneous disease representing the most aggressive breast cancer (BC) subtype. Lack of Estrogen Receptor alpha (ERα), progesterone receptor (PR) and epidermal growth factor receptor 2 (HER2/neu) expression makes TNBC immune to common therapies, significantly limiting the treatment options and suggesting the need to identify novel therapeutic targets. It was previously reported that Estrogen Receptor beta (ERβ) is expressed in a fraction of TNBC patients, where its presence correlates with improved patient outcome. Recently, we demonstrated an oncosuppressive ERβ effect in TNBC cell models expressing exogenous ERβ. On the other hand, it was shown that ERβ is involved in miRNA-mediated gene regulation in hormone-responsive BC cells, suggesting similar effect also in TNBC. To verify this hypothesis, we performed small non-coding RNA (sncRNA) sequencing on three engineered cell lines belonging to different TNBC molecular subtypes. ERβ-specific changes of sncRNA profile revealed that the major part of deregulated molecules are subtype specific, with only few commonly regulated ones. In order to validate the obtained results, we performed sncRNA profiling of 12 ERβ positive and 32 ERβ negative TNBC tissues, whose receptor status was assessed by immunohistochemistry in our previous research. Also here, ERβ-specific group of deregulated sncRNAs was identified. Interestingly, comparison of obtained in vitro and in vivo results revealed 2 differentially expressed miRNAs, displaying the same behavior in all three analyzed cell lines and tissues. In concordance with our previous results, IPA signaling pathway analysis performed on genes targeted by deregulated miRNAs highlighted downregulation of cholesterol biosynthesis pathway and upregulation of several signaling processes. Taken together, these findings suggest that ERβ is able to exert its oncosuppressive role in TNBC through miRNA-mediated regulation of gene expression.
2020-04-04 | E-MTAB-8807 | biostudies-arrayexpress
Project description:The initiation of breast cancer is associated with increased expression of tumor-promoting estrogen receptor α (ERα) protein and decreased expression of tumor-suppressive ERβ protein. However, the mechanism underlying this process is unknown. Here we show that Pescadillo/PES1, an estrogen-inducible protein that is over-expressed in breast cancer, can regulate the balance between ERα and ERβ. PES1 enhances transcriptional activity of ERα and reduces that of ERβ, and modulates many estrogen-responsive genes. Consistent with this regulation of ERα and ERβ transcriptional activity, PES1 increases the stability of the ERα protein and decreases that of ERβ through the ubiquitin-proteasome pathway, mediated by the carboxyl terminus of Hsc70-interacting protein (CHIP). Moreover, PES1 can transform normal human mammary epithelial cells and is required for estrogen-induced breast tumor growth in nude mice. Further analysis of clinical samples showed that expression of PES1 correlates positively with ERα expression and negatively with ERβ expression, and predicts good clinical outcome in breast cancer. Our data demonstrate that PES1 contributes to breast tumor growth through regulating the balance between ERα and ERβ and may be a better target for the development of drugs that selectively regulate ERα and ERβ activities.
2012-06-10 | GSE38621 | GEO
Project description:The closely related transcription factors (TFs), estrogen receptors ERα and ERβ, regulate divergent gene expression programs and proliferative outcomes in breast cancer. Utilizing MCF-7 breast cancer cells with ERα, ERβ, or both receptors as a model system to define the basis of differing response specification by related TFs, we show that these TFs and their key coregulators, SRC3 and RIP140, generate overlapping as well as unique chromatin-binding and transcription-regulating modules. Cistrome and transcriptome analyses and use of clustering algorithms delineated 11 clusters representing different chromatin-bound receptor and coregulator assemblies that could be functionally associated through enrichment analysis with distinct patterns of gene regulation and preferential coregulator usage, RIP140 with ERβ and SRC3 with ERα. The receptors modified each other’s transcriptional effect, and ERβ countered the proliferative drive of ERα through several novel mechanisms associated with specific binding site clusters. Our findings delineate distinct TF-coregulator assemblies that function as control nodes specifying precise patterns of gene regulation, proliferation, and metabolism, as exemplified by two of the most important nuclear hormone receptors in human breast cancer. MCF-7 cells expressing endogenous ERalpha were infected with adenovirus carrying either estrogen receptor beta (AdERb) or no insert (Ad) at multiplicity of infection (moi) of 50. ERβ only cells were generated from these cells by knockdown of ERα in parental cells using the following siERα sequences from Dharmacon: forward, 5’-UCAUCGCAUUCCUUGCAAAdTdT-3’, and reverse, 5’-UUUGCAAGGAAUGCGAUGAdTdT-3’. siRNA experiments were performed as previously described, and resulted in knocknown of ERα mRNA and protein by greater than 95% (GSE4006, PMID 16809442). Briefly, cells were transfected with 20 nM siCtrl [GSE4006] or siERα for 48 h after infection. Then cells were treated with 0.1% EtOH (Veh) or 10 nM E2 (Sigma-Aldrich) for 24h. All experiments were conducted with two replicates. key words; Adenovirus infection,siRNA knock-down, ligand treatment
2013-07-05 | E-GEOD-42347 | biostudies-arrayexpress
Project description:The RNA-binding protein Argonaute 2 (AGO2) is a key effector of RNA-silencing pathways It exerts a pivotal role in microRNA maturation and activity, and can modulate chromatin remodeling, transcriptional gene regulation and RNA splicing. The Estrogen Receptor beta (ERβ) is endowed with oncosuppressive activities, antagonizing hormone-induced carcinogenesis and inhibiting growth and oncogenic functions in luminal-like breast cancers (BCs), where its expression correlates with a better prognosis of the disease. Applying interaction proteomics coupled to mass spectrometry (MS) to characterize nuclear factors cooperating with ERβ in gene regulation, we identify AGO2 as a novel partner of ERβ in human BC cells. ERβ-AGO2 association was confirmed in vitro and in vivo both in the nucleus and in cytoplasm and is shown to be RNA-mediated. ChIP-Seq demonstrates AGO2 association to a large number of ERβ binding sites, and total and nascent RNA-Seq in ERβ+ vs ERβ- cells, and before and after AGO2 knock-down in ERβ+ cells, reveals a widespread involvement of this factor in ERβ-mediated regulation of gene transcription rate and RNA splicing. Moreover, isolation and sequencing by RIP-Seq of ERβ-associated long and small RNAs in the cytoplasm suggests involvement of the nuclear receptor in RISC loading, indicating that it may able to control directly also mRNA translation efficiency and stability.These results demonstrate that AGO2 can act as a pleiotropic functional partner of ERβ, indicating that both factors are endowed with multiple roles in the control of key cellular functions
2017-04-25 | E-MTAB-4359 | biostudies-arrayexpress