Project description:To investigate the oxidant sensitivity of E/ER regulated gene expression, E/ER regulated genes are identified using E deprivation or; ER-alpha siRNA knockdown; and oxidative stress responsive is determined by 8hr exposure to diamide, hydrogen peroxide and menadione Experiment Overall Design: MCF7 cells were treated under various conditions to identifiy oxidative stress responsive E/ER regulated genes. Association of these genes with respect to tumor phenotypes are assessed
Project description:To investigate the oxidant sensitivity of E/ER regulated gene expression, E/ER regulated genes are identified using E deprivation or ER-alpha siRNA knockdown; and oxidative stress responsive is determined by 8hr exposure to diamide, hydrogen peroxide and menadione Keywords: biomarker identification
Project description:MCF-7 TET Off cells (MCF-7 wt) were used to produce stable clones expressing ER-beta tagged with TAP-tag respectively at the C-term and at the N-term (C-TAP-ER-beta and N-TAP-ER-beta) or expressing ER-alpha tagged (C-TAP-ER-alpha) as previously described.Cells were cultured in standard growth conditions, then were lysed and RNA was extracted using TRIzol method.Total RNA were fluorescently labelled, amplified and hybridized in triplicate (MCF7-TAP and C-TAP-ER-alpha) and in duplicate (C-TAP-ER-beta_A, C-TAP-ER-beta_B, N-TAP-ER-beta) for 18 hours on Illumina v2 MicroRNA Expression BeadChips and after scanning, analysis was performed with GenomeStudio v.2010.1 software, for quality control and miRNA expression analysis.
Project description:SEPN1 is a type II protein of the endoplasmic reticulum (ER) whose loss of function gives rise to a collection of debilitating autosomal recessive myopathies gathered under the umbrella term of SEPN1-related myopathy (RM). At the moment, SEPN1-RM lacks an effective pharmacological treatment; thus, the medical management of the disease is only supportive. The potentially fatal diaphragmatic weakness leading to respiratory insufficiency in patients still ambulant is the main reason for medical concerns. Thus, studies on SEPN1-RM pathogenesis are necessary to implement a targeted pharmacological therapy aimed at relieving the general muscle weakness and the more worrisome diaphragmatic dysfunction. Here, we show a physical and functional interaction between SEPN1 and the ER stress mediator ERO1 alpha (henceforth, ERO1). Both SEPN1 and ERO1 are involved in the redox regulation of proteins into the ER, although in an opposite way SEPN1 imposes a less oxidant ER poise while ERO1 a more oxidant one, conceivable with a reductase function of SEPN1 and an oxidase one of ERO1. Furthermore, both are mainly localized in a region of the ER in close contact with mitochondria termed mitochondria-associated membranes (MAMs) and their loss impacts oppositely on the short-range MAMs, thereby impinging ER-mitochondria Ca2+ dynamics, OXPHOS, and bioenergetics. We find that ERO1 depletion restores the impaired short-range MAMs due to SEPN1 loss together with mitochondrial ATP. ERO1 knockout in a mouse background of SEPN1 loss blunts ER stress and the consequent Unfolded Protein Response (UPR) while it rescues the diaphragmatic weakness by improving ER/mitochondria contacts, calcium dynamics, and OXPHOS. Importantly, treatments of SEPN1 knock out mice with the chemical chaperone tauroursodeoxycholic acid (TUDCA) mimic the results of ERO1 loss improving calcium dynamics, OXPHOS, ER/mitochondria contacts, thereby rescuing diaphragmatic weakness as well. In addition, TUDCA-treated SEPN1-RM patients-derived myoblasts show a dynamic dose-dependent increase in ATP levels under ER stress conditions suggesting improved mitochondrial function. Thus, our findings point to the ERO1 axis in the pathogenesis of SEPN1-RM thereby impinging on MAMs and mitochondria bioenergetics and recall for the efficacy of a pharmacology therapy with ad hoc ER stress/ERO1 inhibitors for SEPN1-RM.
Project description:We were interested in determining what genes might be controlled by TFAP2C and/or TFAP2A, either directly or indirectly through regulation of ER-alpha and potentially other signaling pathways. We performed an microarray analysis in MCF7 cells with elimination of either TFAP2C or TFAP2A. The patterns of gene expression with alteration of TFAP2 activity were compared to changes in expression induced by estrogen exposure. Knock-down of TFAP2C in the presence of estrogen altered the pattern of several known ERalpha-regulated genes and a number of genes outside the estrogen-regulated pathways. Keywords: Various siRNA treatments
Project description:We were interested in determining what genes might be controlled by TFAP2C and/or TFAP2A, either directly or indirectly through regulation of ER-alpha and potentially other signaling pathways. We performed an microarray analysis in MCF7 cells with elimination of either TFAP2C or TFAP2A. The patterns of gene expression with alteration of TFAP2 activity were compared to changes in expression induced by estrogen exposure. Knock-down of TFAP2C in the presence of estrogen altered the pattern of several known ERalpha-regulated genes and a number of genes outside the estrogen-regulated pathways. Experiment Overall Design: 6 samples were analyzed. Experiment Overall Design: 1. MCF7 cells treated with TFAP2C siRNA, without the presence of estrogen. Experiment Overall Design: 2.MCF7 cells treated with TFAP2C siRNA, with the presence of estrogen. Experiment Overall Design: 3.MCF7 cells treated with TFAP2A siRNA, without the presence of estrogen. Experiment Overall Design: 4.MCF7 cells treated with TFAP2A siRNA, with the presence of estrogen. Experiment Overall Design: 5.MCF7 cells with no siRNA treatment, without the presence of estrogen. Experiment Overall Design: 6.MCF7 cells with no siRNA treatment, with the presence of estrogen.
Project description:Estrogen Receptor ? (ER?) has central role in hormone-dependent breast cancer and its ligand-induced functions have been extensively characterized. However, evidence exists that ER? has functions which are independent of ligands. In the present work, we investigated the binding of ER? to chromatin in absence of ligands, and its function(s) on gene regulation. We demonstrated that in MCF7 breast cancer cells unliganded ER? binds to more than four thousands chromatin sites. Unexpectedly, although almost entirely comprised in the larger group of estrogen-induced binding sites, we found that unliganded-ER? binding is specifically linked to genes with developmental functions, as compared to estrogen-induced binding. Moreover, we found that siRNA-mediated downregulation of ER? in absence of estrogen is accompanied by changes in the expression levels of hundreds of coding and noncoding RNAs. Downregulated mRNAs showed enrichment in genes related to epithelial cell growth and development. Stable ER? downregulation using shRNA, which caused cell-growth arrest, was accompanied by increased H3K27me3 at ER? binding sites. Finally, we found that FOXA1 and AP2? binding to several sites is decreased upon ER? silencing, suggesting that unliganded ER? participates, together with other factors, to the maintenance of the luminal-specific cistrome in breast cancer cells. Examination of unligandend estrogen receptor alpha (apoER?) DNA interactions in control and ER? siRNA treated MCF7 cells.
Project description:We report the first discovery of naturally occurring ESR1Y537C and ESR1Y537S mutations in MCF7 and MCF7 ESR1-positive cell-lines after acquisition of resistance to long-term-estrogen-deprivation (LTED) and subsequent resistance to fulvestrant (ICIR).
Project description:Estrogen receptor alpha plays a critical role in breast cancer and is a major target in endocrine therapy. HIF-1 alpha have been associated with ER alpha and predict a worse outcome. Recent studies indicate that histone demethylase JMJD2B is a HIF-1 alpha target. However, little is known about the biological functions of JMJD2B, especially in breast cancer. To elucidate the mechanism by which JMJD2B reguates gene expression in normoxia and hypoxia, MCF-7 breast cancer cells were depleted forJMJD2B in normoxia and hypoxia. Our results provide insight into JMJD2B regulation of gene expression in breast cancer cells in normoxia and hypoxia. MCF7 cells were subjected to transfection with siRNA controls and two different siRNA oligos against JMJD2B for 24 hours. Cells were treated in normoxia and hypoxia for another 16 hours.
Project description:We report the ER alpha regulatory network of Tamoxifen resistance MCF7 cell line using the Chromatin immunoprecipitated high-throughput sequencing technology (ChIP-seq). By Integrating the gene expression data (previously reported) with the ChIP-seq data, we generated ER alpha regulatory network and pathways. For ER alpha regulatory network, hub TFs with enriched motifs were identified from ER alpha peak together with PolII peaks. We then scan the position weight matrix (PWM) of ER alpha peak region of certain gene to find out the regulatory relationship between hub TF and normal TF. For regulatory pathway, genes were grouped base on their expression value at 4 different time point. Then the hub TF that plays important role in each time point of each group was identified. This study provides a framework for the application of ChIP-seq and gene expression data for the construction of ER alpha regulatory network. 4 different ChIP-seq dataset in Tamoxifen resistance MCF7 cell line