The effect of miRNA overexpression on gene expression profile of MCF-7 cells
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE14847 | GEO | 2009/08/18
SECONDARY ACCESSION(S): PRJNA112123
REPOSITORIES: GEO
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Project description:To identify microRNAs impacting estrogen receptor ERα expression in breast cancer, we have screened ER-positive breast cancer cells with a library of pre-miRs, and systematically monitored the ERα expression by protein lysate microarrays. There was a significant enrichment of the in silico predicted ERα targeting microRNAs among the hits. The most potent pre-miRs miR-18a/b, miR-193b, miR-206, and miR-302c, were confirmed to directly target ERα and to repress estrogen-responsive genes. The effect of miRNA overexpression on gene expression profile of MCF-7 cells was studied. Furthermore, miR-18a and miR-18b showed increased expression in ERα-negative as compared to ERα-positive clinical tumors. In summary, we present systematic and direct functional and correlative clinical evidence on microRNAs inhibiting ERα signaling in breast cancer. MCF-7 cells (300 000 per well on 6-well plates) were transfected with an siRNA for ERα or with Ambion pre-miR� constructs for miR-18a, miR-193b, miR-206, miR-302c, or pre-miR negative control #1 (scrambled pre-miR) at 20 nM, and incubated for 24h.
2010-04-09 | E-GEOD-14847 | biostudies-arrayexpress
Project description:Estrogen receptor alpha (ERα) is a nuclear receptor linked to progression of the majority of human breast cancers. Following activation ERα regulates the transcription of target genes via DNA binding. Through a genome wide approach we have identified a subset of microRNAs (miRNAs or miRs) modulated by ERα. Among them, miRNAs encoded from 2 paralogous clusters, miR-17-92 and miR-106a-363, were up-regulated. In addition, increased expression of miR-424, miR-542-3p and miR-450, located within the same genomic region and down-regulation of miR-181 family members were observed during the estrogenic response. We observed that ERα alone is sufficient for sustained transcription of miR-17-92 and we show that levels of this cluster increase earlier than miRNAs encoded by it, implicating post-transcriptional regulation. Since miR-17-92 a pri-miRNA, is immediately cleaved by DROSHA to pre-miR-18a, this regulation occurs during the formation of the mature molecule from the precursor. Moreover, pre-miR-18a was significantly up-regulated in ERα-positive breast cancers compared to ERα-negative breast cancers. We also demonstrate that the miRNAs belonging to these paralogous clusters target and down-regulate ERα, while a subset of cluster-derived miRNAs inhibit protein translation of its major oncogenic transcriptional p160 co-activator by targeting AIB1 revealing a negative autoregulatory feedback loop. This pathway adds to the highly regulated cellular response to estrogen that fine tunes ERα transcriptional activity and cell proliferation.
2009-05-01 | GSE14685 | GEO
Project description:Purpose The analysis of breast cancer residual tumors after neoadjuvant chemotherapy (nCT) may be useful for identifying new biomarkers. MicroRNAs are known to be involved in oncogenic pathways and treatment resistance of breast cancer. Our aim was to determine the role of miR-18a, a member of the miR-17-92a cluster, in breast cancer behavior and outcome after nCT. Methods Pre- and post-nCT tumor miR-18a expression was retrospectively assessed by qRT-PCR in 121 patients treated with nCT and was correlated with survival outcomes and with clinical and pathological characteristics. Breast cancer-derived MCF-7 and MDA-MB-231 cell lines were transfected with miR-18a and anti-miR-18a to evaluate the biological effects of this molecule. In addition, whole-transcriptome expression analysis was performed. Results High miR-18a expression in post-nCT residual tumors was found to be associated with a significantly worse overall survival [hazard ratio (HR): 2.80, 95% confidence interval (CI): 1.01–7.76] and a strong trend towards a poorer disease-free survival (HR: 2.44, 95% CI: 0.99–5.02) compared to low miR-18a expressing post-nCT residual tumors. Clinical and experimental data were found to be in conformity with the proliferative effects of miR-18a, which showed a significant correlation with Ki67 and MYBL2 expression, both in pre- and post-nCT tumors and in public databases. In vitro analysis of the role of miR-18a in breast cancer-derived cell lines showed that a high expression of miR-18a was associated with a low expression of the estrogen receptor (ER), a decreased sensitivity to tamoxifen and an enrichment in luminal B and endocrine resistance gene expression signatures. Conclusions From our data we conclude that post-nCT miR-18a expression in breast cancer serves as a negative prognostic marker, especially in luminal tumors. Clinical, in vitro and in silico data support the role of miR-18a in breast cancer cell proliferation and endocrine resistance and suggest its potential utility as a biomarker for additional adjuvant treatment in patients without a pathologic complete response to neoadjuvant therapy.
2019-05-27 | GSE102121 | GEO
Project description:Estrogen receptor alpha (ERα) is a nuclear receptor linked to progression of the majority of human breast cancers. Following activation ERα regulates the transcription of target genes via DNA binding. Through a genome wide approach we have identified a subset of microRNAs (miRNAs or miRs) modulated by ERα. Among them, miRNAs encoded from 2 paralogous clusters, miR-17-92 and miR-106a-363, were up-regulated. In addition, increased expression of miR-424, miR-542-3p and miR-450, located within the same genomic region and down-regulation of miR-181 family members were observed during the estrogenic response. We observed that ERα alone is sufficient for sustained transcription of miR-17-92 and we show that levels of this cluster increase earlier than miRNAs encoded by it, implicating post-transcriptional regulation. Since miR-17-92 a pri-miRNA, is immediately cleaved by DROSHA to pre-miR-18a, this regulation occurs during the formation of the mature molecule from the precursor. Moreover, pre-miR-18a was significantly up-regulated in ERα-positive breast cancers compared to ERα-negative breast cancers. We also demonstrate that the miRNAs belonging to these paralogous clusters target and down-regulate ERα, while a subset of cluster-derived miRNAs inhibit protein translation of its major oncogenic transcriptional p160 co-activator by targeting AIB1 revealing a negative autoregulatory feedback loop. This pathway adds to the highly regulated cellular response to estrogen that fine tunes ERα transcriptional activity and cell proliferation. 4 time points (0hr,3hr,6hr,12hr) and 4 treatments (TO,JP,TO+TET,JP13+TET) x 3 biological replicates of each condition = 24 arrays
2010-06-25 | E-GEOD-14685 | biostudies-arrayexpress
Project description:Breast (mammary) cancers in human (BC) and canine (CMT) patients share clinical, pathological, and molecular similarities that suggest dogs may be a useful translational model. Many cancers, including BC, shed exosomes that contain microRNAs (miRs) into the microenvironment and circulation, and these may represent biomarkers of metastasis and tumor phenotype. Three normal canine mammary epithelial cell (CMEC) cultures and 5 CMT cell lines were grown in serum-free media. Exosomes were isolated from culture media by ultracentrifugation then profiled qualitatively. CMEC and CMT cell lines shed round, “cup-shaped” exosomes approximately 150-200 nm by dynamic light scattering (DLS) and immunopositive for exosomal marker CD9 using Western blot. Exosomal small RNA was deep-sequenced on an Illumina HiSeq2500 sequencer and validated by qRT-PCR. Deep-sequencing averaged ~15 million reads/sample. 338 unique miRs were detected, with 145 having > ±1.5-fold difference between one or more CMT and CMEC samples. Gene ontology analysis revealed that the upregulated miRs in this exosomal population regulate a number of relevant oncogenic networks. Several miRNAs including miR-18a, miR-19a and miR-181a were predicted in silico to target the canine estrogen receptor (ESR1α). CMEC and CMT cells shed exosomes in vitro that contain differentially expressed miRs. CMT exosomal RNA expresses a limited number of miRs that are up-regulated relative to CMEC, and these are predicted to target biologically relevant hormone receptors and oncogenic pathways. These results may inform future studies of circulating exosomes and the utility of miRs as biomarkers of breast cancer in women and dogs.
2018-08-13 | GSE116881 | GEO
Project description:The Estrogen Receptor alpha (ERα) controls key cellular functions in hormone responsive breast cancer by assembling in large functional multiprotein complexes. ERα ligands are classified as agonists and antagonist, according to the response they elicit, thus the molecular characterization of the of ERα nuclear iteractome composition following estrogen and antiestrogen stimulation whose is needed to understand their effects on estrogen target tissues, in particular breast cancer. To this aim interaction proteomics coupled to mass spectrometry (MS) was applied to map the ERα nuclear interacting partners in MCF7 breast cancer cell nuclei following estrogen and antiestrogen stimuli.
2020-09-02 | PXD018709 | Pride
Project description:MicroRNAs (miRNAs) regulate a wide range of cellular signaling pathways and biological processes in both physiological and pathological states such as cancer. We have previously identified miR-135b as a direct regulator of androgen receptor (AR) protein level in prostate cancer (PCa). We wanted to further explore the relationship of miR-135b to hormonal receptors, particularly estrogen receptor α (ERα). Here we show that miR-135b expression inversely correlates with ER protein in two independent breast cancer (BCa) patient cohorts (101 and 1302 samples) and with AR protein in 47 PCa patient samples. We identify ERα as a novel miR-135b target by demonstrating miR-135b binding to the 3’UTR of the ERα and decreased ERα protein and mRNA level in breast cancer cells upon miR-135b overexpression. miR-135b inhibits proliferation of hormone receptor positive cancer cell lines as shown by overexpression in ERα-positive BCa cells (MCF-7) and AR-positive PCa cells (LNCaP, 22Rv1) when grown in 2D. To identify other genes regulated by miR-135b we performed gene expression studies and found a potential link to the hypoxia-inducible factor-1α (HIF1α) pathway. We show that miR-135b influences the protein level of the inhibitor for hypoxia-inducible factor-1 (HIF1AN), which also demonstrated an inverse correlation with miR-135b in a cohort of breast tumor samples. Taken together, our study demonstrates that miR-135b regulates ERα, AR and HIF1AN protein levels and proliferation in ERα -positive breast and AR-positive-prostate cancer cells.
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2013-07-31 | GSE45362 | GEO
Project description:Using the orthotopic breast cancer xenograft model of basal-like breast cancer MDA-MB-231 line, we have found that the expression of miRNAs encoded by MIR17HG was significantly decreased in cells isolated from spontaneous lung metastases compared to cells from primary tumors grown in orthotopic sites. We investigated the role of a MIR17HG family member, miR-18a, in primary tumor growth and pulmonary metastasis from the orthotopic site. We demonstrated that enforced expression of exogenous miR-18a, significantly limited continuous growth of primary tumors in mammary gland fat pads and reduced spontaneous lung metastasis. Further investigation on the mechanism of miR-18a action led to the finding that the expression of HIF1A, a key regulator of tumor metastasis, was regulated by miR-18a. Enforced miR-18a expression significantly decreased HIF1A expression at both mRNA and protein levels, resulting in altered transcriptional response and decreased survival of cells in response to Cobalt(II) chloride (CoCl2), a hypoxia-mimicking agent. Conversely, miR-18a knockdown significantly increased HIF1A expression levels and enhanced cell survival in response to CoCl2. Analysis of expression data of human breast tumor tissues showed that miR-18a expression is inversely correlated with HIF1A expression in basal-like breast tumors, supporting a role of miR-18a in restricting HIF1A expression in this subtype of breast cancer. In addition, we demonstrated that hypoxia inhibits miR-18a expression, likely through MYC inactivation. Furthermore, gene expression and functional analysis revealed that miR-18a also plays a role in regulating cell adhesion, migration and invasion. Taken together, this study provides evidence for a novel role of miR-18a to inhibit breast cancer metastasis. Our results suggest that miR-18a downregulation might provide tumor cells survival/growth advantage under hypoxic pressure in basal-like breast cancer. A lung metastatic subline, designated as MB231RN-LM, was derived from MDA-MB-231 breast cancer cells through in vivo selection. The MB231RN-LM cells were stably transfected with has-miR-18a or control vector and treated with 200uM Cobalt(II) chloride (CoCl2, a hypoxia-mimicking agent) for 4 hr. A total of 8 samples were subjected to microarray analysis, with two biological repeats for each experiment condition.
2013-07-31 | E-GEOD-45362 | biostudies-arrayexpress
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