In blood, the transcription factor C/EBPa is essential for myeloid differentiation and has been implicated in regulating self-renewal of fetal liver hematopoietic stem cells (HSCs). However, its function in adult HSCs is unknown. Here, using an inducible knockout model, we found that C/EBPa deficient adult HSCs underwent a pronounced expansion with enhanced proliferation, characteristics resembling fetal liver HSCs. Consistently, transcription profiling of C/EBPa deficient HSCs revealed a gene expression program similar to fetal liver HSCs. Moreover we observed that age-specific C/EBPa expression correlated with its inhibitory effect on the HSC cell cycle. Mechanistically, we identified N-Myc as a C/EBPa downstream target. C/EBPa upregulation during HSC transition from an active fetal state to a quiescent adult state was accompanied by down-regulation of N-Myc, and loss of C/EBPa resulted in de-repression of NMyc. Our data establish that C/EBPa acts as a molecular switch between fetal and adult states of HSC in part via transcriptional repression of the proto-oncogene N-Myc.
C/EBPa controls acquisition and maintenance of adult haematopoietic stem cell quiescence.
Specimen part
View SamplesWe defined the C/EBPa signature characterized by a set of genes which are upregulated upon C/EBPa activation. In order to identify the C/EBPa signature, we performed microarray gene expression analysis of K562 cells stably expressing p42-C/EBPa-ER after activating the C/EBPa construct to translocate to the nucleus for 6 hours with beta-estradiol.
The gene signature in CCAAT-enhancer-binding protein α dysfunctional acute myeloid leukemia predicts responsiveness to histone deacetylase inhibitors.
Cell line, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
DNMT1-interacting RNAs block gene-specific DNA methylation.
Cell line, Treatment
View SamplesWe used the microarray analysis to detail the gene expression profile from the leukemic cell line HL-60
DNMT1-interacting RNAs block gene-specific DNA methylation.
Cell line
View SamplesIdentification of the all RNA species associated with DNMT1. Using a comparative genome-scale approach we identified and correlated the RNA species physically associated with DNMT1 and proximal to the annotated genes to the methylation status of the corresponding loci and expression levels of the respective genes. This comparative approach delineated the first -DNMT1 centered- 'epitranscriptome' map, a comprehensive map cross-referencing DNMT1-interacting transcripts to (i) DNA methylation and (ii) gene expression profile. Overall design: Relationship between DNMT1-RNA interactions, DNA methylation and gene expression
DNMT1-interacting RNAs block gene-specific DNA methylation.
Cell line, Subject
View SamplesWe have found the existence of a Bmi1+ population in the adult heart contributing to the organ low-rate turnover and repair with the generation of new cardiomyocytes. We show that the Bmi1+ population is a sub-population of the cardiac Sca-1+ progenitor cells. We have analyzed the gene profile by deep-sequencing (RNA-Seq) of Bmi1+ and Sca-1+Bmi1- cells in homeostatic heart condition. On the other hand, we have compared gene profile by deep-sequencing (RNA-Seq) of Bmi1+ cells in homeostatic condition versus Bmi1+ cells 5 days after myocardial infarction (MI). Analysis of RNA-Seq data revealed a differential expression signature between both subsets of cardiac stem/progenitors cells in homeostatic condition and also differences between Bmi1+ cells after AMI versus homeostatic condition. Overall design: Examination of gene profile of 2 different cardiac stem /progenitors subsets (Bmi1+ and Sca-1+Bmi1-) co-existing inthe adult heart under steady state. Examination of gene profile of Bmi1+ cardiac stem cells in homeostatic condition versus MI
Age-related oxidative stress confines damage-responsive Bmi1<sup>+</sup> cells to perivascular regions in the murine adult heart.
No sample metadata fields
View SamplesMutation or epigenetic silencing of the transcription factor C/EBP is observed in ~10% of patients with acute myeloid leukemia (AML). In both cases, a common global gene expression profile is observed, but down-stream targets relevant for leukemogenesis are not known. Here we identify Sox4 as a direct target of C/EBP whereby its expression is inversely correlated with C/EBP activity. Downregulation of Sox4 abrogated increased self-renewal of leukemic cells and restored their differentiation. Gene expression profiles of leukemia initiating cells (LICs) from both Sox4 overexpression and murine mutant C/EBP AML models clustered together, but differed from other types of AML. Our data demonstrate that Sox4 overexpression resulting from C/EBP inactivation contributes to the development of leukemias with a distinct LIC phenotype.
Sox4 is a key oncogenic target in C/EBPα mutant acute myeloid leukemia.
Specimen part
View SamplesTo guarantee blood supply throughout adult life hematopoietic stem cells (HSCs) need to carefully balance between self-renewing cell divisions and quiescence. Identification of genes controlling HSC self-renewal is of utmost importance given that HSCs are the only stem cells with broad clinical applications. Transcription factor PU.1 is one of the major regulators of myeloid and lymphoid development. Recent reports suggest that PU.1 mediates its functions via gradual expression level changes rather than binary on/off states. So far, this has not been considered in any study of HSCs and thus, PU.1s role in HSC function has remained largely unclear. Here we demonstrate using hypomorphic mice with an engineered disruption of an autoregulatory feedback loop that decreased PU.1 levels resulted in loss of key HSC functions, all of which could be fully rescued by restoration of proper PU.1 levels via a human PU.1 transgene. Mechanistically, we found excessive HSC cell divisions and altered expression of cell cycle regulators whose promoter regions were bound by PU.1 in normal HSCs. Adequate PU.1 levels were maintained by a mechanism of direct autoregulation restricted to HSCs through a physical interaction of a -14kb enhancer with the proximal promoter. Our findings identify PU.1 as novel regulator controling the switch between cell division and quiescence in order to prevent exhaustion of HSCs. Given that even moderate level changes greatly impact stem cell function, our data suggest important therapeutic implications for leukemic patients with reduced PU.1 levels. Moreover, we provide first proof, that autoregulation of a transcription factor, PU.1, has a crucial function in vivo. We anticipate that our concept of how autoregulation forms an active chromosomal conformation will impact future research on transcription factor networks regulating stem cell fate.
Sustained PU.1 levels balance cell-cycle regulators to prevent exhaustion of adult hematopoietic stem cells.
Specimen part
View SamplesTranscriptional profiling of histone methyltransferase SUV39H1-selective small molecule inhibitor F5446-induced genes in human colon carcinoma cells. Tumor cells were treated with F5446 for 48h and used for RNA isolation. The treated cells were compared to untreated control cells. The objective is to identify genes that are regulated by H3K9me3 in the metastatic human colon carcinoma cells.
SUV39H1 regulates human colon carcinoma apoptosis and cell cycle to promote tumor growth.
Treatment
View SamplesHead and neck cancer is a hetergeneous disease. Based on previoulsy defined molecular subtypes we associated gene expression with response to different compounds. We used microarry gene expression for molecular subtyping
Basal subtype is predictive for response to cetuximab treatment in patient-derived xenografts of squamous cell head and neck cancer.
No sample metadata fields
View Samples