Differentiation of naïve CD4+ T cells into effector (Th1, Th2 and Th17) and induced regulatory (iTreg) T cells requires lineage-specifying transcription factors and epigenetic modifications that allow appropriate repression or activation of gene transcription. The epigenetic silencing of cytokine genes is associated with the repressive H3K27 trimethylation mark, mediated by Ezh2 or Ezh1 methyltransferase components of the polycomb repressive complex 2 (PRC2). EZH2 over-expression and activating mutations are implicated in tumorigenesis and correlate with poor prognosis in several tumor types 35. This spurred the development of EZH2 inhibitors which, by inducing tumor cell growth arrest and cell death, show therapeutic promise in cancer. A role for Ezh2 in suppressing Th1 and Th2 cytokine production and survival has recently been reported. It is not entirely clear whether Ezh2-PRC2 plays a role in H3K27me3 in cytokine loci in naïve CD4+ T cells and whether H3K27me3 has a non-redundant role in T helper cell lineage differentiation and survival. Here, we investigate the effects of T cell-specific Ezh2 deletion to determine the role that Ezh2-PRC2 plays in regulating the fate of differentiating naïve CD4+ T cells. Loss of Ezh2 altered the expression of 1328 genes in Th0 and 1979 genes in iTreg cells. Gene expression changes were positively correlated in both cell types, indicating that Ezh2 targets similar genes in these cells. As expected, Ifng was one of the genes most increased in expression by following loss of Ezh2. In addition, expression of Tbx21 homolog Eomes, a transcription factor that regulates IFNG production, was also significantly increased. We then performed H3K27me3 ChIP-seq on Ezh2fl/fl and Ezh2fl/fl.CD4Cre Th0 cells. Consistent with cellular phenotype and RNA-seq data, we observed a loss of the H3K27me3 at Eomes, Il4 and Il10 loci . Very low levels of H3K27me3 marks were present at Ifng and Tbx21 loci in differentiated Ezh2fl/fl Th0 cells, suggesting that upon differentiation, upregulation or activation of transcription factors accounts for IFNG overproduction. A significant loss of H3K27me3 was observed >2kb upstream of Gata3 locus , however this did not result in increased transcription . Of the 22381 genes tested for changes in H3K27me3, 1360 showed a statistically significant decrease in Ezh2fl/fl.CD4Cre Th0 cells, compared to wildtype. Furthermore, 404 of these genes also showed a concomitant gain in expression in Ezh2fl/fl.CD4Cre Th0 cells, suggesting that these loci are likely direct Ezh2-PRC2 targets. Overall design: There are 3 biological replicates each of Ezh2fl/fl.CD4Cre and Ezh2fl/fl in both Th0 and iTreg cells for the RNA-seq experiment. There are 2 biological replicates each of Ezh2fl/fl.CD4Cre and Ezh2fl/fl in Th0 cells for the ChIP-seq experiment.
The polycomb repressive complex 2 governs life and death of peripheral T cells.
No sample metadata fields
View SamplesThere is increasing evidence that breast and other cancers originate from and are maintained by a small fraction of stem/progenitor cells with self-renewal properties. Whether such cancer stem/progenitor cells originate from normal stem cells based on initiation of a de novo stem cell program, by reprogramming of a more differentiated cell type by oncogenic insults or both remains unresolved. A major hurdle in addressing these issues is lack of immortal human stem/progenitor cells that can be deliberately manipulated in vitro. We present evidence that normal and human telomerase reverse transcriptase (hTERT)-immortalized human mammary epithelial cells (hMECs) isolated and maintained in DFCI-1 medium retain a fraction with progenitor cell properties. These cells co-express basal, luminal and stem/progenitor cell markers. Clonal derivatives of progenitors co-expressing these markers fall into two distinct types: K5+/K19- (Type I) and K5+/K19+ (Type II). We show that both types of progenitor cells have self-renewal and differentiation ability. Through microarray analysis, we want to identify genes and pathways linked to human mammary epithelial stem/progenitor cell self-renewal and differentiation.
Telomerase-immortalized human mammary stem/progenitor cells with ability to self-renew and differentiate.
Sex, Specimen part
View SamplesWe used microarrays to detail the global programme of gene expression after knockdown of Ecdysoneless in hMECs
The cell cycle regulator ecdysoneless cooperates with H-Ras to promote oncogenic transformation of human mammary epithelial cells.
Specimen part, Cell line
View SamplesAda3 (alteration/deficiency in activation) is a transcriptional adaptor that forms a core structural component of multiple HAT complexes. In order to gain insights into physiological roles of Ada3, we made a conditional knockout mouse for Ada3 which was early embryonic lethal. Deletion of Ada3 in MEFs by using Adenovirus-Cre showed changes in global histone acetylation.
Mammalian alteration/deficiency in activation 3 (Ada3) is essential for embryonic development and cell cycle progression.
Specimen part
View SamplesAcute myeloid leukemia (AML) continues to have the lowest survival rates of all leukemias. Therefore, new therapeutic strategies are urgently needed to improve clinical outcomes for AML patients. Here, we report a novel role for Wilms’ tumor 1-associated protein (WTAP) in pathogenesis of AML. We have performed RNA-Seq in K562 cells with knockdown of WTAP to ascertain which genes it regulates. Overall design: We have 2 replicates of total RNA for K562 cells and 2 replicates with WTAP knocked down
WTAP is a novel oncogenic protein in acute myeloid leukemia.
Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Identification of mRNAs bound and regulated by human LIN28 proteins and molecular requirements for RNA recognition.
Cell line
View SamplesHuman LIN28A and B are RNA-binding proteins (RBPs) conserved in animals with important roles during development and stem cell reprogramming. We used Photoactivatable-Ribonucleoside-Enhanced Crosslinking and Immunoprecipitation (PAR-CLIP) in HEK293 cells and identified a largely overlapping set of ~3,000 mRNAs at ~9,500 sites located in the 3UTR and CDS. In vitro and in vivo, LIN28 preferentially bound single-stranded RNA containing a uridine-rich element and one or more flanking guanosines, and appeared to be able to disrupt base-pairing to access these elements when embedded in predicted secondary structure. In HEK293 cells, LIN28 protein binding mildly stabilized target mRNAs and increased protein abundance. The top targets were its own mRNAs and those of other RBPs and cell-cycle regulators. Alteration of LIN28 protein levels also negatively regulated the abundance of some, but not all let-7 miRNA family members, indicating sequence-specific binding of let-7 precursors to LIN28 proteins and competition with cytoplasmic miRNA biogenesis factors.
Identification of mRNAs bound and regulated by human LIN28 proteins and molecular requirements for RNA recognition.
Cell line
View SamplesHuman LIN28A and B are RNA-binding proteins (RBPs) conserved in animals with important roles during development and stem cell reprogramming. We used Photoactivatable-Ribonucleoside-Enhanced Crosslinking and Immunoprecipitation (PAR-CLIP) in HEK293 cells and identified a largely overlapping set of ~3,000 mRNAs at ~9,500 sites located in the 3’UTR and CDS. In vitro and in vivo, LIN28 preferentially bound single-stranded RNA containing a uridine-rich element and one or more flanking guanosines, and appeared to be able to disrupt base-pairing to access these elements when embedded in predicted secondary structure. In HEK293 cells, LIN28 protein binding mildly stabilized target mRNAs and increased protein abundance. The top targets were its own mRNAs and those of other RBPs and cell-cycle regulators. Alteration of LIN28 protein levels also negatively regulated the abundance of some, but not all let-7 miRNA family members, indicating sequence-specific binding of let-7 precursors to LIN28 proteins and competition with cytoplasmic miRNA biogenesis factors. Overall design: To assess whether miRNAs are regulated by LIN28B we analyzed the miRNA levels of LIN28B overexpressing and LIN28B-depleted cells using small RNA cDNA library sequencing. The RBP LIN28B was depleted by siRNAs and the expression levels was compared to mock-transfected HEK293 cells.
Identification of mRNAs bound and regulated by human LIN28 proteins and molecular requirements for RNA recognition.
Cell line, Subject
View SamplesHuman LIN28A and B are RNA-binding proteins (RBPs) conserved in animals with important roles during development and stem cell reprogramming. We used Photoactivatable-Ribonucleoside-Enhanced Crosslinking and Immunoprecipitation (PAR-CLIP) in HEK293 cells and identified a largely overlapping set of ~3,000 mRNAs at ~9,500 sites located in the 3’UTR and CDS. In vitro and in vivo, LIN28 preferentially bound single-stranded RNA containing a uridine-rich element and one or more flanking guanosines, and appeared to be able to disrupt base-pairing to access these elements when embedded in predicted secondary structure. In HEK293 cells, LIN28 protein binding mildly stabilized target mRNAs and increased protein abundance. The top targets were its own mRNAs and those of other RBPs and cell-cycle regulators. Alteration of LIN28 protein levels also negatively regulated the abundance of some, but not all let-7 miRNA family members, indicating sequence-specific binding of let-7 precursors to LIN28 proteins and competition with cytoplasmic miRNA biogenesis factors. Overall design: LIN28 protein PAR-CLIP
Identification of mRNAs bound and regulated by human LIN28 proteins and molecular requirements for RNA recognition.
Subject
View SamplesMast cells, activated by antigen via the high affinity receptor for IgE (FcRI), release an array of pro-inflammatory mediators that contribute to allergic disorders such as asthma and anaphylaxis. The KIT ligand, stem cell factor (SCF), is critical for mast cell expansion, differentiation and survival, and, under acute conditions, enhances mast cell activation. However, extended SCF exposure in vivo conversely protects against fatal antigen-mediated anaphylaxis. In investigating this dichotomy, we identified a novel mode of regulation of the mast cell activation phenotype through SCF-mediated programming. We found that mouse bone marrow-derived mast cells chronically exposed to SCF displayed a marked attenuation of FcRI-mediated degranulation and cytokine production. The hypo-responsive phenotype was not a consequence of altered signals regulating calcium flux or protein kinase C, but of ineffective cytoskeletal reorganization, with evidence implicating a down-regulation of expression of the Src kinase Hck. Collectively, these findings demonstrate a major role for SCF in the homeostatic control of mast cell activation with potential relevance to mast cell-driven disease and the development of novel approaches for the treatment of allergic disorders.
Stem cell factor programs the mast cell activation phenotype.
Specimen part, Treatment
View Samples