Translocations involving the MLL genes are frequently found in Acute Myeloid Leukemia (AML) and are associated with poor prognosis. The MLL fusion proteins act as aberrant transcription factor activating a transcriptional program that transforms the cells, potentially through collaboration with other transcription factors. To investigate this we searched gene expression profiles from patients with MLL-rearranged AML compared with normal hematopoietic progenitor cells for transcriptional regulators and found targets of C/EBP to be up-regulated in the AML samples, suggesting that C/EBP might collaborate with MLL fusion proteins in the initial transformation process. We could show that transformation by MLL fusion proteins is dependent on C/EBP activity both in early progenitors as well as in GMPs. In contrast, C/EBP was found to be indispensable in an already established leukemia. These results suggest that C/EBP play an important role in the early transforming event of leukemogenesis.
Initiation of MLL-rearranged AML is dependent on C/EBPα.
Specimen part
View SamplesIn this study, we use a conditional mouse model for Cebpa to investigate the significance of C/EBP in HSCs. The frequency of HSCs is unaltered following deletion of C/EBP, however, upon serial transplantations of either full BM or purified HSCs, the stem cells and stem cell activity is lost. This is not due to increased proliferation, but rather caused by a shift from quiescence to apoptosis with a resultant exhaustion of the stem cell pool. We identify direct C/EBP target genes by combining genome-wide C/EBP ChIP-seq analysis in stem and progenitor cells with gene expression data from HSC with and without C/EBP. Furthermore, we explore the impact of C/EBP on active and repressive histone modifications by doing functional genome-wide ChIP-seq analysis of H3K4Me3 and H3K27Me3 in stem and progenitor cells with and without C/EBP.
C/EBPα is required for long-term self-renewal and lineage priming of hematopoietic stem cells and for the maintenance of epigenetic configurations in multipotent progenitors.
Sex, Specimen part
View SamplesWithin the bone marrow, hematopoietic stem cells differentiate and give rise to diverse blood cell types and functions. Currently, hematopoietic progenitors are defined using surface markers combined with functional assays that are not directly linked with the in vivo potential or gene regulatory mechanisms. Here we comprehensively identify myeloid progenitor subpopulations by transcriptional sorting of single cells from the bone marrow. We describe multiple progenitor subgroups showing unexpected transcriptional priming towards seven differentiation fates, but no progenitors with a mixed state. Transcriptional differentiation is correlated with combinations of known and previously undefined transcription factors, suggesting the process is tightly regulated. Histone maps and knockout assays are consistent with the transcriptional states while traditional transplantation experiments are only partially overlapping myeloid transcriptional priming. Our analyses uncover the function of the underlying regulatory mechanisms for several sub groups and establishes a general framework for dissecting hematopoiesis. Overall design: Bone marrow Lin- cKit+ Sca1- myeloid progenitors mRNA profiles from single cells were generated by deep sequencing of thousands of single cells, sequenced in several batches in an Illumina NextSeq Please note that [1] raw data files were processed as single-ended file since second read (mate) files contain only cell/molecule barcodes and therefore, not provided. This information was appended to the fastq entry header [2] The ''experimental_design.txt'' file explains the correspondence of each single cell (WXXXX) in the ''umitab.txt'' to a sample (ABXXXX).
Transcriptional Heterogeneity and Lineage Commitment in Myeloid Progenitors.
Specimen part, Cell line, Treatment, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Cell growth in aggregates determines gene expression, proliferation, survival, chemoresistance, and sensitivity to immune effectors in follicular lymphoma.
No sample metadata fields
View SamplesFollicular Lymphomas are blood tumors growing as spheres in patients. Before this study, there was no experimental model mimicking the 3D organization of these in vivo tumors. We develop such a model, called MALC, and observed a progressive enrichment in quiescent cells in these with time of culture; these cells were sorted, as their cycling counterparts, and their transcriptomes were compared. We used microarrays to detail the differential global gene expression profile between quiescent and cycling cells isolated from MALC.
Cell growth in aggregates determines gene expression, proliferation, survival, chemoresistance, and sensitivity to immune effectors in follicular lymphoma.
No sample metadata fields
View SamplesFollicular Lymphomas are blood tumors growing as spheres in patients. Before this study, there was no experimental model mimicking the 3D organization of these in vivo tumors. We develop such a model, called MALC, and performed a pan-genomic comparative analysis between MALC and classical suspension cultures. We used microarrays to detail the global gene expression profile induced by aggregated growth of lymphoma cells.
Cell growth in aggregates determines gene expression, proliferation, survival, chemoresistance, and sensitivity to immune effectors in follicular lymphoma.
No sample metadata fields
View SamplesExhaustion markers are expressed by T lymphocytes in Follicular Lymphoma (FL). Through these, TIM-3 has been recently identified as a poor pronostic factor when expressed by FL CD4+ T cells.
Impaired functional responses in follicular lymphoma CD8<sup>+</sup>TIM-3<sup>+</sup> T lymphocytes following TCR engagement.
Specimen part, Subject
View SamplesRetinoic acid receptors (RARs) , and are key regulators of embryonic development. Hematopoietic differentiation is regulated by RAR, and several types of leukemia show aberrant RAR activity. We demonstrate that RAR plays an important role in cellular memory and imprinting by regulating the CpG methylation status of specific promoter regions.
Epigenetic regulation by RARα maintains ligand-independent transcriptional activity.
Cell line, Treatment
View SamplesThe t(12;21) translocation is the most common genetic rearrangement in childhood acute lymphoblastic leukemia (ALL) and gives rise to the TEL-AML1 fusion gene, which functions as a transcription factor.
The TEL-AML1 fusion protein of acute lymphoblastic leukemia modulates IRF3 activity during early B-cell differentiation.
Cell line, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
NSD2 links dimethylation of histone H3 at lysine 36 to oncogenic programming.
Sex, Age, Specimen part, Cell line
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