Project description:Cord blood-derived stem cells were in vitro cultured in the presence of 40 ng/ml SCF, 20 ng/ml IL6 and 2 microM lysophosphatidic acid for 5 week. Then mast cells were magnetically isolated and further cultured for 4 days in the presence or absence of 2 ng/ml TGF-betaI. Total RNA was isolated and processed according to the Agilent Low-input RNA Linear Amplification Kit and microarray hybridization protocol. Experiment Overall Design: 5 biological replicates from 5 donors and one technical replicate (dye-swap)
Project description:The estrogen receptor is the master transcriptional regulator of breast cancer phenotype and the archetype of a molecular therapeutic target. We mapped all estrogen receptor and RNA polymerase II binding sites on a genome-wide scale, identifying the authentic cis binding sites and target genes, in breast cancer cells. Combining this unique resource with gene expression data demonstrates distinct temporal mechanisms of estrogen-mediated gene regulation,particularly in the case of estrogen-suppressed genes. Furthermore, this resource has allowed the identification of cis-regulatory sites in previously unexplored regions of the genome and the cooperating transcription factors underlying estrogen signaling in breast cancer. Experiment Overall Design: This Series currently contains the gene expression data accompaning Carroll JS et al. Nature Genetics 38,1289-1297(2006). MCF7 cells were stimulated with 100 nM estrogen for 0, 3, 6, or 12h. All experiments were performed in triplicate.
Project description:Screens for agents that specifically kill epithelial cancer stem cells (CSCs) have not been possible due to the rarity of these cells within tumor cell populations and their relative instability in culture. We describe here an approach to screening for agents with epithelial CSC-specific toxicity. We implemented this method in a chemical screen and discovered compounds showing selective toxicity for breast CSCs. One compound, salinomycin, reduces the proportion of CSCs by >100-fold relative to paclitaxel, a commonly used breast cancer chemotherapeutic drug. Treatment of mice with salinomycin inhibits mammary tumor growth in vivo and induces increased epithelial differentiation of tumor cells. In addition, global gene expression analyses show that salinomycin treatment results in the loss of expression of breast CSC genes previously identified by analyses of breast tissues isolated directly from patients. This study demonstrates the ability to identify agents with specific toxicity for epithelial CSCs Experiment Overall Design: Experimentally transformed HMLER breast cancer cells were treated in culture with either paclitaxel (10nM) or salinomycin (1uM) for one week. There were three biologic replicates for each treatment condition.
Project description:We identified GSK3 as a regulator of GBM cell survival using microarray analysis, small molecule and genetic inhibitors of GSK3 activity. Various molecular and genetic approaches were then employed to dissect out the molecular mechanisms responsible for GSK3 inhibition-induced cytotoxicity. Experiment Overall Design: RNA extracted from U251 cells treated with DMSO or Enzastaurin for indicated time were hybridized to Affymetrix expression arrays (HG_U133-Plus_2) to detect changes in gene expression caused by Enzastaurin. Three replicates per sample were used.
Project description:Gene expression changes caused by estrogen treatment of breast cancer cells that re-express ERalpha was investigated by infecting ER-negative MDA-MB-231 breast cancer cells for 24 h with recombinant adenovirus encoding full-length human ERalpha (Ad-ERalpha) or control vector (Ad-LacZ), and treating them with 0·01% ethanol (vehicle control) or 10-8 M 17beta-estradiol (E2). After 48 h of treatment, total RNA was isolated and used for transcript profiling on Affymetrix GeneChips. Three independent biological replicates of this experiment were carried out.
Project description:The unfolded protein response (UPR), a signaling pathway triggered by endoplasmic reticulum (ER) stress, is induced by a range of environmental factors. Here we describe the identification and characterization of a synthetic small molecule, erstressin, which activates the UPR. Erstressin induced rapid phosphorylation of PERK and eIF2a and the alternative splicing of XBP-1, hallmark initiating events of the UPR. Further, erstressin activated the transcription of multiple genes involved in the UPR. Coincident with these effects, erstressin also downregulated the transcription of the inflammation-associated enzyme inducible nitric oxide synthase (iNOS) in cytokine-activated cells. A close analog of erstressin that failed to induce the UPR did not attenuate expression of iNOS, suggesting that both biological effects of erstressin were mediated by a common mechanism. Further, the structurally-distinct ER stressor thapsigargin also inhibited iNOS expression. Together these chemical genetic studies reveal an unanticipated anti-inflammatory role for the UPR. Experiment Overall Design: We utilized microarrays to understand the global effect of a novel compund, erstressin, on cytokine stimulated cells over time.
Project description:Human estrogen-responsive breast cancer cell line ZR-75-1 was treated with 10nM of 17 beta-estradiol. Gene expression was analyzed on total RNA extracted before or after 1, 2, 4, 6, 8, 12, 16, 20, 24, 28 and 32 hours hormonal stimulation. For each condition 2 technical replicates were performed, except the reference sample (before stimulation - 0h) which was in quadruplicate and the 4h sample in triplicate.
Project description:Human dendritic cells were co-cultured with carcinoma cells (A549 or SK-MES-1) or were treated with lipopolysaccharide (LPS).There were three biological replicates of each condition plus untreated controls giving 12 samples and microarrays in total.Samples were processed with standard Affymetrix IVT protocols and hybridised to Affymetrix Human Genome U133 GeneChips. Data were processed in Bioconductor using RMA.
Project description:Using a chromatin immunoprecipitation-paired end diTag cloning and sequencing strategy, we mapped estrogen receptor alpha (ERalpha) binding sites in MCF-7 breast cancer cells. We identified 1,234 high confidence binding clusters of which 94% are projected to be bona fide ERalpha binding regions. Only 5% of the mapped estrogen receptor binding sites are located within 5 kb upstream of the transcriptional start sites of adjacent genes, regions containing the proximal promoters, whereas vast majority of the sites are mapped to intronic or distal locations (>5 kb from 5' and 3' ends of adjacent transcript), suggesting transcriptional regulatory mechanisms over significant physical distances. Of all the identified sites, 71% harbored putative full estrogen response elements (EREs), 25% bore ERE half sites, and only 4% had no recognizable ERE sequences. Genes in the vicinity of ERalpha binding sites were enriched for regulation by estradiol in MCF-7 cells, and their expression profiles in patient samples segregate ERalpha-positive from ERalpha-negative breast tumors. The expression dynamics of the genes adjacent to ERalpha binding sites suggest a direct induction of gene expression through binding to ERE-like sequences, whereas transcriptional repression by ERalpha appears to be through indirect mechanisms. Our analysis also indicates a number of candidate transcription factor binding sites adjacent to occupied EREs at frequencies much greater than by chance, including the previously reported FOXA1 sites, and demonstrate the potential involvement of one such putative adjacent factor, Sp1, in the global regulation of ERalpha target genes. Unexpectedly, we found that only 22%-24% of the bona fide human ERalpha binding sites were overlapping conserved regions in whole genome vertebrate alignments, which suggest limited conservation of functional binding sites. Taken together, this genome-scale analysis suggests complex but definable rules governing ERalpha binding and gene regulation. Experiment Overall Design: We used oligonucleotide expression microarrays (Affymetrix GeneChip U133 Plus 2.0) to identify estradiol (E2)-responsive genes in the estrogen-receptor positive breast cancer cell line, MCF7. MCF7 cells were grown to 30-50% confluency and exposed to 10 nM E2 (or vehicle only) at 12, 24, and 48 hours. Each timepoint was performed in triplicate (ie, biological replicates). Total RNA was isolated from cells using the Qiagen RNeasy kit, and 5 micrograms of total RNA was amplified, labeled and hybridized to the array according to the manufacturer’s protocols.