Transcription profiling by array of human mammary epithelial cells grown in 2D monolayers with or without EGF and insulin, or 3D Matrigel culture, after treatment with 4-hydroxytamoxifen
ABSTRACT: MCF10A MycER cells were grown either on 2D monolayer culture in the presence of complete growth medium, in the absence of EGF and insulin or in 3D Matrigel culture for 20 days to form acinar structures. MycER was activated with 4-hydroxytamoxifen (4-OHT) in all samples for 2 or 48 h. Control cells were treated with ethanol. The aim of the study was to explore the effect of different growth conditions on gene expression changes in response to c-Myc activation.
Project description:Expression data from ERBB2 over-expression and EGF stimulation in MCF10A cells The cells were transduced with retroviruses encoding vector control (pBabe) or pBabe-ErbB2. After infection cells were switched to assay medium supplemented with only 2% horse serum and no EGF. For EGF stimulation, cells transduced with empty vector were treated with EGF at 50 ng/ml for 2 hours before harvesting.
Project description:Using basal‐like untransformed cells, MCF10A, as a model system, data from our laboratory showed that both mRNAs and microRNAs exhibit dynamic changes in expression following EGF stimulation (Amit et al, 2007; Avraham et al, 2010; Kostler et al, 2013). We further demonstrated that the inducible mRNAs and microRNAs are embedded into regulatory subnetworks, which are deregulated in diverse tumor types. Considering the emerging roles for long noncoding RNAs (lncRNAs) in metastasis of breast cancer (Serviss et al, 2014), we raised the possibility that some EGF‐inducible lncRNAs might play a role in basal‐like breast cancer. Thus, MCF10A cells were stimulated with EGF (10 ng/ml) for 0, 20, 40, 60, 120, 240 and 480 minutes. RNA was then extracted from cells and expression of lncRNAs was measured using Agilent SurePrint microarrays.
Project description:To ensure proper gene regulation within constrained nuclear space, chromosomes facilitate access to transcribed regions, while compactly packaging all other information. Recent studies revealed that chromosomes are organized into megabase-scale domains that demarcate active and inactive genetic elements, suggesting that compartmentalization is important for genome function. Here we show that very specific long-range interactions are anchored by cohesin/CTCF sites, but not cohesin-only or CTCF-only sites, to form a hierarchy of chromosomal loops. These loops demarcate topological domains and form intricate internal structures within them. Post-mitotic nuclei deficient for functional cohesin exhibit global architectural changes associated with loss of cohesin/CTCF contacts and relaxation of topological domains. Transcriptional analysis shows that this cohesin-dependent perturbation of domain organization leads to widespread gene deregulation of both cohesin-bound and non-bound genes. Our data thereby support a role for cohesin in the global organization of domain structure and suggest that domains function to stabilize the transcriptional programs within them. Hi-C, ChIP-Seq and RNA-Seq experiments were conducted in mouse neural stem cells and mouse astrocytes
Project description:Tumor invasion into surrounding stromal tissue is a hallmark of high-grade, metastatic cancers. Oncogenic transformation of human epithelial cells in culture can be triggered by activation of v-Src kinase, resulting in increased cell motility, invasiveness and tumorigenicity and provides a valuable model for studying how changes in gene expression cause cancer phenotypes. Here, we show that epithelial cells transformed by activated Src show increased levels of DNA methylation and that the methylation inhibitor, 5-AzaC, potently blocks the increased cell motility and invasiveness induced by Src activation. A proteomic screen for chromatin regulators acting downstream of activated Src identified the replication-dependent histone chaperone CAF1 as an important factor for Src-mediated increased cell motility and invasion. We show Src causes a 5-AzaC-sensitive decrease in both mRNA and protein levels of the p150 (CHAF1A) and p60 (CHAF1B), subunits of CAF1. Depletion of CAF1 in untransformed epithelial cells using siRNA was sufficient to recapitulate the increased motility and invasive phenotypes characteristic of transformed cells without activation of Src. Maintaining high levels of CAF1 by exogenous expression suppressed the increased cell motility and invasiveness phenotypes when Src was activated. These data identify a critical role of CAF1 in the dysregulation of cell invasion and motility phenotypes seen in transformed cells and also highlight an important role for epigenetic remodeling through DNA methylation for Src-mediated induction of cancer phenotypes.
Project description:Epidermal growth factor (EGF) is a key regulatory growth factor activating a myriad of processes affecting cell proliferation and survival that are relevant to normal development and disease. Here we have used a combined approach to study the EGF dependent transcriptome of HeLa cells. We obtained mRNA expression profiles using multiple long oligonucleotide based microarray platforms (from Agilent, Operon, Febit, and Illumina) in combination with digital gene expression profiling (DGE) with the Illumina Genome Analyzer I (GA-I). By applying a procedure for cross-platform data meta-analysis based on rank product and global ancova tests, we establish a well validated gene set with transcript levels altered after EGF treatment. We used this robust gene list to build higher order networks of gene interaction by interconnecting associated networks, supporting and extending the important role of the EGF signaling pathway in cancer. In addition, we found a whole new set of genes previously unrelated to the currently accepted EGF associated cellular functions, among which are metallothionein genes. We propose the use of global genomic cross-validation to generate more reliable datasets derived from high content technologies (microarrays or deep sequencing). This approach should help to improve the confidence of downstream in silico functional inference analyses based on high content data. Keywords: treated vs. untreated comparison, time course Time course experiment comparing HeLa gene expression in response to EGF analyzed on different microarray platforms (Agilent, IMPPC, Illumina, and Operon) and by digital gene expression using short read high throughput tag sequencing. Three independent experiments were performed where HeLa cells were serum deprived for 24 hours and were either left untreated or treated with EGF for 6, and 24 h and harvested for RNA extraction. Technical dye swap duplicates were performed for each of the three biological replicates in both time points. Comparative genomic hybridization of HeLa cell genomic DNA versus poooled genomic DNA from blood obtained from human females conducted on commercial oligonucleotide microarrays (Human Genome CGH Microarray Kit 244A, Agilent Technologies) in order to assess DNA dosage dependence of gene expression levels and response to EGF. Digital gene expression using short read high throughput tag sequencing data submitted to NCBI's SRA
Project description:Stem cell functions require activation of stem cell-intrinsic transcriptional programs as well as intimate extracellular interactions with a niche microenvironment. How the core pluripotency transcriptional machinery controls residency of stem cells in the niche microenvironment is unknown. Here we show that the helix loop helix transcriptional regulators Id (Inhibitors of DNA binding) are the master regulators that coordinate stem cell activities with anchorage of neural stem cells (NSCs) to the embryonic and postnatal niche. Conditional inactivation of Id genes (Id1, Id2 and Id3) in the mouse NSC compartment triggered detachment of embryonic and post-natal NSCs from the ventricular and vascular niche respectively, followed by premature differentiation. Through an unbiased interrogation of the gene modules directly targeted by deletion of Id genes in NSCs, we discovered that Id proteins repress the bHLH-mediated activation of Rap1GAP, thus serving to maintain the GTPase activity of RAP1, a key mediator of cell adhesion. Preventing the elevation of Rap1GAP efficiently countered the consequences of Id loss on NSC-niche interaction and stem cell identity. Thus, by preserving anchorage to the extracellular environment of NSCs, Id activity synchronizes NSC functions to residency in the specialized niche. We generated Id-cTKO mice carrying a Cre-recombinase-oestrogen-receptor-T2 (Cre-ER) allele targeted to the ubiquitously expressed ROSA26 locus (Id-cTKO-Rosa-Cre-ER). In this system, 4-hydroxytamoxifen (4-OHT) releases the Cre recombinase inhibition and allows recombination of genomic loxP sites. Indeed, efficient deletion of Id1 and Id2 with complete loss of Id protein expression was detectable after treatment of NSCs with 4-OHT for 72 h. Total RNA was extracted from triplicate samples of Id-cTKO-Rosa-Cre-ER NSCs treated for different times (6 h, 12 h, 18 h, 24 h, 48 h, 96 h, 144 h) with 4-OHT or control vehicle and used for analysis on Illumina MouseWG-6 expression BeadChip. The raw array data was normalized using the Bioconductor package Lumi using quantile normalization.
Project description:This SuperSeries is composed of the following subset Series: GSE14987: Expression data from ERBB2 over-expression and EGF stimulation in MCF10A cells GSE14988: Expression data from DHT stimulation vs. control in LNCaP cells Refer to individual Series
Project description:Basal-like carcinoma is a subtype of breast cancer that is characterized by poor prognosis and high intratumor heterogeneity. Using a basal-like breast epithelial line, we have identified two anti-correlated gene-expression programs that arise among single extracellular matrix (ECM)-attached cells during organotypic 3D culture. The first program contains TGFBR3, a high-affinity receptor for transforming growth factor β (TGFβ) and other related ligands. The second program contains the JUND transcription factor together with the basal-like marker, KRT5. By disrupting the TGFBR3 and JUND programs individually, we reveal an important circuit for 3D morphogenesis that is wired together by four negative-feedback loops. Computational modeling of this circuit showed that it could exhibit damped, antiphase oscillations when excited with small impulses of TGFβ-like ligand. We directly visualize the circuit's spontaneous dynamics in organotypic cultures by using live-cell imaging with engineered pathway reporters. Importantly, we show that the essence of the JUND-TGFBR3 expression circuit holds true in early basal-like tumors that heterogeneously express KRT5. Correlated JUND-KRT5 expression depends critically on contact with stromal ECM and local expression of tenascin C. This work illustrates how complex tumor heterogeneities can be deconstructed into intrinsic single-cell expression circuits that are modulated by the microenvironment. Gene expression analysis of outer ECM-attached vs. inner cells of MCF10A-5E clones grown in organotypic 3D culture at day 6. Total RNA was isolated from ~50 outer ECM-attached cells and ~50 inner cells, each separately microdissected from 8 micron sections of MCF10A structures at day 6 of morphogenesis. Total RNA was amplified in quadruplicate, and hybridized to HumanRef-8 v2.0 Expression BeadChips (Illumina).
Project description:Combination therapy with Smo and PI3K inhibitors results in a synergistic effect in reducing tumor growth in PTEN-deficient Glioblastoma. To identify consequences of combination therapy with an Smo inhibitor and a PI3K inhibitor on a genome-wide scale, we performed Affymetrix microarrays with two different PTEN-deficient GBMs treated with single drugs or combination therapy. A small set of genes was significantly affected by combination therapy in hBT70 and/or hBT112, including several genes implicated in GBM prognosis, or identified as targets of Shh, PI3K or S6 pathways 29-33 . There are two different human GBM tumors (BT70 and BT112). Both are PTEN deficient. Samples were treated with DMSO (Control), LDE225 at 1 uM for 5 days, BKM 120 100 nM for 5 days, or LDE225 1 uM and BKM 120 100 nM for 5 days (Combo). Two biological replicates of each condition were analyzed.