Malignant gliomas constitute one of the most significant areas of unmet medical need, due to the invariable failure of surgical eradication and their marked molecular heterogeneity. Accumulating evidence has revealed a critical contribution by the Polycomb axis of epigenetic repression. However, a coherent understanding of the regulatory networks affected by Polycomb during gliomagenesis is still lacking. Here we integrate transcriptomic and epigenomic analyses to define Polycomb-dependent networks that promote gliomagenesis, validating them both in two independent mouse models and in a large cohort of human samples. We found that Polycomb dysregulation in gliomagenesis affects transcriptional networks associated to invasiveness and de-differentiation. The dissection of these networks uncovers Zfp423 as a crtitical Polycomb-dependent transcription factor whose silencing negatively impacts survival. The anti-gliomagenic activity of Zfp423 requires interaction with the SMAD proteins within the BMP signaling pathway, pointing to a novel synergic circuit through which Polycomb inhibits BMP signaling. Overall design: Transcriptomic analysis of two different stages of gliomagenesis
Polycomb dysregulation in gliomagenesis targets a Zfp423-dependent differentiation network.
Specimen part, Cell line, Subject
View SamplesTranscription factor (TF)-induced reprogramming of somatic cells into induced pluripotent stem cells (iPSC) is associated with genome-wide changes in chromatin modifications. Polycomb-mediated histone H3 lysine-27 trimethylation (H3K27me3) has been proposed as a defining mark that distinguishes the somatic from the iPSC epigenome. Here, we dissected the functional role of H3K27me3 in TF-induced reprogramming through the inactivation of the H3K27 methylase EZH2 at the onset of reprogramming. Our results demonstrate that surprisingly the establishment of functional iPSC proceeds despite global loss of H3K27me3. iPSC lacking EZH2 efficiently silenced the somatic transcriptome and differentiated into tissues derived from the three germ layers. Remarkably, the genome-wide analysis of H3K27me3 in Ezh2 mutant iPSC cells revealed the retention of this mark on a highly selected group of Polycomb targets enriched for developmental regulators controlling the expression of lineage specific genes. Erasure of H3K27me3 from these targets led to a striking impairment in TF-induced reprogramming. These results indicate that PRC2-mediated H3K27 trimethylation is required on a highly selective core of Polycomb targets whose repression enables TF-dependent cell reprogramming.
Cell reprogramming requires silencing of a core subset of polycomb targets.
Specimen part
View SamplesHigh temporal resolution RNAseq timecourse of mouse ES differentiation Investigations of transcriptional responses during developmental transitions typically use time courses with intervals that are not commensurate with the timescales of known biological processes. Moreover, such experiments typically focus on protein-coding transcripts, ignoring the important impact of long noncoding RNAs. We evaluated coding and noncoding expression dynamics at unprecedented temporal resolution (6-hourly) in differentiating mouse embryonic stem cells and report the effects of increased temporal resolution on the characterization of the underlying molecular processes. Overall design: Biological duplicate 120 hours of undirected mouse ES cell differentiation sampled 6 hourly Biological duplicate, low passage number (P18) W9.5 ESCs were cultured and differentiated as described previously [PMID:18562676; 17286599]. Cultures were harvested every six hours from the induction of differentiation to 120 hours post differentiation induction. Total RNA from cultures was purified using Trizol (Life Technologies) and DNase treatment was performed by RQ1 DNase (Promega) according to the manufacturer’s instructions. RNA integrity was measured on a Bioanalyzer RNA Nano chip (Agilent). RNA-Seq library preparation and sequencing of Poly-A-NGS libraries generated from 500 ng total RNA using SureSelect Strand Specific RNA Library Preparation Kit (Agilent) according to the manufacturer’s instructions. Paired-end libraries were sequenced to the first 100 bp on a HiSeq 2500 (Illumina) on High Output Mode. Library sequencing quality was determined using FastQC (Babraham Bioinformatics) and FastQ Screen (Babraham Bioinformatics). Illumina adaptor sequence and low quality read trimming (read pair removed if < 20 base pairs) was performed using Trim Galore! (Babraham Bioinformatics: www.bioinformatics.babraham.ac.uk/). Tophat2 [PMID:23618408] was used to align reads to the December 2011 release of the mouse reference genome (mm10) as outlined by Anders et al.[PMID:23975260]. Read counts data corresponding to GENCODE vM2 transcript annotations were generated using HTSeq[PMID:25260700]. All analyses were performed in the R Statistical Environment [PMID:18000755]. Briefly, counts data were background corrected and normalized for library size using edgeR [PMID:19910308], then transformed using voom[PMID:24485249] for differential expression analysis using LIMMA[PMID: 16646809].
High resolution temporal transcriptomics of mouse embryoid body development reveals complex expression dynamics of coding and noncoding loci.
Specimen part, Cell line, Subject, Time
View SamplesAdvances in sequencing-based genomic profiling present a new challenge of explaining how changes in DNA/RNA are translated into proteins linking genotypes to phenotypes. The developing erythroid cells require highly coordinated gene expression and metabolism, and serve as a unique model in dissecting regulatory events in development and disease. Here we compare the proteomic and transcriptomic changes in human hematopoietic stem/progenitor cells and lineage-committed erythroid progenitors, and uncover pathways related to mitochondrial biogenesis enhanced through post-transcriptional regulation. Two principal mitochondrial factors TFAM and PHB2 are tightly regulated at the protein level and indispensable for mitochondria and erythropoiesis. mTORC1 signaling is progressively enhanced to promote translation of mitochondrial proteins during erythroid specification. Genetic and pharmacological perturbation of mTORC1 or mitochondria impairs erythropoiesis. Our studies suggest a new mechanism for regulation of mitochondrial biogenesis through mTORC1-mediated protein translation, and may have direct relevance to the hematological defects associated with mitochondrial diseases and aging. Overall design: Transcriptional profiling in human primary fetal and adult CD34+ hematopoietic stem/progenitor cells (HSPCs) erythroid progenitor cells (ProEs) by RNA-seq analysis.
Regulation of mitochondrial biogenesis in erythropoiesis by mTORC1-mediated protein translation.
No sample metadata fields
View SamplesEGR3 expression is upregulated in human prostate cancer compared to normal prostate tissue and is associated with absence of relapse, while low EGR3 expression in tumors is predicitive of disease relapse (Pio et al., PLOS One 2013; 8(1):e54096). However the function of EGR3 in prostate cancer is unknown. Human prostate cancer cells M12 containing high levels of EGR3 were used for shRNA-mediated silencing of EGR3. Gene expression analysis of EGR3 knockdown cells reveals a role in inflammation and the existence of a crosstalk with the NFkB pathway.
Early growth response 3 (Egr3) is highly over-expressed in non-relapsing prostate cancer but not in relapsing prostate cancer.
Cell line, Treatment
View SamplesGene expression profiling was performed in ccRCC cells, which either express both HIF1alpha and HIF2alpha (either naturally or by virtue of induced expression of HIF1alpha) or express HIF2alpha alone (either naturally or by virtue of a HIF1alpha shRNA), to identify genes regulated by HIF1alpha in ccRCC cells.
Genetic and functional studies implicate HIF1α as a 14q kidney cancer suppressor gene.
Specimen part, Cell line
View SamplesEndometriosis is a complex pathological condition in which multiple components are involved in the disease development and clinical outcome. Endometriosis is mainly an inflammatory codition estrogen-dependent, with unknown pathogenesis, that is characterized by dissemination of edometrium tissue in ectopic position (ovary or pelvic peritoneum). Two main theories rise the pathologic onset: the presence of retrograde menstruation and celomic metaplasia in the pelvic peritoneum, that can occur for development defects. Endometriosis is related not only to genetic or immunological changes and to environmental pollution factors, as the endocrine interferents. The disease phenotype results from multiple events (genetics and enviromental), thus it is difficult to find a single gene as causative while is more probable that a gene network/s might involved in the onset and mantainement of the disease state. The peculiarity of endometriosis rely on the tissue speificity manteinance in the ectopic position, where it responds to the hormone stimuli as the tissue in the eutopic position.
Transcriptional profiling of endometriosis tissues identifies genes related to organogenesis defects.
Specimen part, Disease, Disease stage, Subject
View SamplesThe global gene expression profiles of ventral prostates of wild type mice and p110 beta transgenic mice.
A constitutively activated form of the p110beta isoform of PI3-kinase induces prostatic intraepithelial neoplasia in mice.
Age, Specimen part, Disease, Disease stage
View SamplesThis SuperSeries is composed of the SubSeries listed below.
The requirement for cyclin D function in tumor maintenance.
Specimen part, Cell line
View SamplesD-cyclins represent components of cell cycle machinery. To test the efficacy of targeting D-cyclins in cancer treatment, we engineered mouse strains which allow acute and global ablation of individual D-cyclins in a living animal. Ubiquitous shutdown of cyclin D1 or inhibition of cyclin D associated kinase activity in mice bearing ErbB2-driven mammary carcinomas halted cancer progression and triggered tumor-specific senescence, without compromising the animals' health. Ablation of cyclin D3 in mice bearing T-cell acute lymphoblastic leukemias (T-ALL) triggered tumorspecific apoptosis. Such selective killing of leukemic cells can be also achieved by inhibiting cyclin D associated kinase activity in mouse and human T-ALL models. Hence, contrary to what one might expect from ablation of a cell cycle protein, acute shutdown of a D-cyclin leads not only to cell cycle arrest, but it also triggers tumor cell senescence or apoptosis, and it affects different tumor types through distinct cellular mechanisms. Inhibiting cyclin D-activity represents a highly-selective anticancer strategy which specifically targets cancer cells without significantly affecting normal tissues.
The requirement for cyclin D function in tumor maintenance.
Cell line
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