Only hematopoietic stem and progenitor cells from cord blood are susceptible to malignant transformation by MLL-AF4 translocations
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA625488 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR11549035.fastq.gz | Fastqsanger.gz | |||
| SRR11549036.fastq.gz | Fastqsanger.gz | |||
| SRR11549037.fastq.gz | Fastqsanger.gz | |||
| SRR11549038.fastq.gz | Fastqsanger.gz | |||
| SRR11549039.fastq.gz | Fastqsanger.gz |
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Project description:MLL rearrangements (MLLr) play a crucial role in leukemogenesis. Dependent on age, major differences exist regarding disease frequency, main fusion partners and prognosis. In infants, up to 80% of acute lymphoid leukemia (ALL) bear t(4;11) resulting in a poor prognosis. In contrast, in adults only 10% of acute myeloid leukemia (AML) bear t(9;11) with an intermediate prognosis. The reasons for these differences are only poorly understood. Recently, we established an efficient human patient-specific CRISPR/Cas9-based MLLr model in hematopoietic stem and progenitor cells (HSPCs) derived from human cord blood (huCB) faithfully mimicking the underlying biology of the disease. Here, we transfer this model into an adult system using HSPCs from adult bone marrow (huBM) allowing us to investigate the impact of the cell of origin and fusion partner on disease development. RNA-Seq uncovered an absent downregulation of FFAR2 in t(4;11) huBM, an epigenetic tumor suppressor, potentially responsible for the inability of MLL-AF4 to immortalize adult cells under myeloid conditions.
2020-07-20 | GSE148714 | GEO
Project description:Mixed lineage leukemia (MLL) (KMT2A) rearrangements (KMT2Ar) play a crucial role in leukemogenesis. Dependent on age, major differences exist regarding disease frequency, main fusion partners and prognosis. In infants, up to 80% of acute lymphoid leukemia (ALL) bear a MLL translocation and half of them are t(4;11), resulting in a poor prognosis. In contrast, in adults only 10% of acute myeloid leukemia (AML) bear t(9;11) with an intermediate prognosis. The reasons for these differences are poorly understood. Recently, we established an efficient CRISPR/Cas9-based KMT2Ar model in hematopoietic stem and progenitor cells (HSPCs) derived from human cord blood (huCB) and faithfully mimicked the underlying biology of the disease. Here, we applied this model to HSPCs from adult bone marrow (huBM) to investigate the impact of the cell of origin and fusion partner on disease development. Both genome-edited infant and adult KMT2Ar cells showed monoclonal outgrowth with an immature morphology, myelomonocytic phenotype and elevated KMT2Ar target gene expression comparable to patient cells. Strikingly, all KMT2Ar cells presented with indefinite growth potential except for MLL-AF4 huBM cells ceasing proliferation after 80 days. We uncovered FFAR2, an epigenetic tumor suppressor, as potentially responsible for the inability of MLL-AF4 to immortalize adult cells under myeloid conditions.
| S-EPMC7352867 | biostudies-literature
Project description:The MLL-AF4 fusion gene is a hallmark genomic aberration in high-risk acute lymphoblastic leukemia in infants. Although it is well-established that MLL-AF4 arises pre-natally during human development, its effects on hematopoietic development in utero remains unexplored. We have created a human-specific in vitro system to study early hemato-endothelial development in MLL-AF4-expressing human embryonic stem cells (hESCs). Differentiation and functional studies as well as clonal analyses and gene expression profiling reveal that expression of MLL-AF4 in hESCs has a phenotypic, functional and gene expression impact. It enhances the specification of hemogenic precursors from hESCs and impairs further hematopoietic commitment of these precursors in favour of the endothelial cell fate. Similar to that reported in cord blood CD34+ hematopoietic stem/progenitor cells (HSPCs), MLL-AF4 expression is not sufficient to transform hESC-derived hematopoietic cells in vitro or in vivo, indicating that additional events may be required to initiate leukemogenesis or that embryonic hematopoiesis is not the appropriate human cellular target for MLL-AF4-mediated leukemogenesis. This work illustrates how hESCs can provide unique insights into human development and further our understanding of how leukemic fusion genes known to arise pre-natally regulate human embryonic hematopoietic specification. MLL is involved in transcriptional regulation and most MLL translocations appear to result in increased expression of Hox genes and hematopoietic genes. We therefore assessed the impact of MLL-AF4 expression on the transcriptome of hESCs. Gene expression profiling performed in MLL-AF4 hESCs revealed that MLL-AF4 preferentially activates transcription. 1826 out of the 3001 genes (61%) expressed were up-regulated in MLL-AF4 hESCs. Human ESC samples were collected during the exponential cell growth phase and stabilized in RNA later. 500 ng of each total RNA sample was labelled with Cy3 using the Quick-Amp Labelling kit and hybridized with the Gene Expression Hybridization kit to a Whole Human Genome Oligo Microarray (Agilent Technologies) following the Manufacturer’s instructions. Each cell line was analyzed as independent duplicates. NEO-expressing (empty lentivector) hESC line was used as the baseline.
2011-06-09 | E-GEOD-29869 | biostudies-arrayexpress
Project description:MLL/AF4 fusion transcript knock-down time course in the MLL/AF4-positive B-cell precursor ALL cell line SEM using MLL/AF4 fusion site-specific siRNAs (siMLL/AF4). The aim was to identify genes responsive to MLL/AF4 expression modulation.
2018-07-21 | GSE71140 | GEO
Project description:The tumorigenesis capacity of MLL-AF4 alone is insufficient for causing leukemia. Based on the finding that an Flt3 gene mutation in the tyrosine kinase domain (TKD) was observed in approximately 15% of MLL leukemia, we investigated synergistic leukemogenesis effects of the two genes in vitro. In a mouse IL3-dependent cell line, 32Dc, the expression of MLL-AF4 and Flt3 TKD was induced using a lentiviral vector. We performed gene expression profiling in the MLL-AF4 and the Flt3 TKD+MLL-AF4 expressing 32Dc cells. The enhancement of Hox genes expression was not identified. However, instead, the expression of S100A6, which was involved in the control of cell proliferation, was synergistically enhanced in the presence of both MLL-AF4 and Flt3 TKD genes. We performed gene expression profiling: 32Dc vs. MLL-AF4 expressing 32Dc, 32Dc vs. Flt3 TKD+MLL-AF4 expressing 32Dc, and MLL-AF4 expressing 32Dc vs. Flt3 TKD+MLL-AF4 expressing 32Dc. A single sample for each expressing cells was analyzed.
2009-03-31 | E-GEOD-14236 | biostudies-arrayexpress
Project description:In our study, we found that MLL-AF4 transcriptionally induces IGF2BP3 and is required for MLL-Af4 mediated leukemogenesis. Deletion of murine Igf2bp3 significantly increased the survival of mice with MLL-Af4 driven leukemia and greatly attenuated disease. Furthermore, Igf2bp3 was necessary for the development of and the self-renewal capacity of MLL-Af4 leukemic initiating cells. eCLIP and transcriptome analysis of MLL-Af4 transformed stem and progenitor cells and primary cells from MLL-Af4 leukemic mice revealed an IGF2BP3-regulated post-transcriptional operon governing tumor cell survival and proliferation. Critical mRNA targets include the Hoxa locus and numerous genes within the Ras signaling pathway. Together, our findings show that IGF2BP3 is an essential positive regulator of MLL-AF4 mediated leukemogenesis and is a potential therapeutic target in this disease.
2021-08-11 | GSE156115 | GEO
Project description:Understanding the underlying molecular mechanisms of defined cancers is crucial for effective personalized therapies. Translocations of the Mixed Lineage Leukemia (MLL) gene produce fusion proteins such as MLL-AF4 that disrupt epigenetic pathways and cause poor prognosis leukemias. Here we find that MLL-AF4 occupies a subset of unmethylated CG-enriched genes in combination with its cofactors Menin/LEDGF and ENL. MLL-AF4 mainly displays a punctate binding pattern near gene promoters, but we also observe a second less common pattern where MLL-AF4 spreads into the gene body and is associated with increased transcription and increased histone H3 lysine 79 methylation (H3K79me2/3). Compared to other H3K79me2/3 marked genes, MLL-AF4 spreading genes are more sensitive to inhibitors of the H3K79 methyltransferase DOT1L. This sensitivity mediates synergistic interactions with additional targeted drug treatments. Therefore, epigenetic spreading and enhanced susceptibility to epidrugs provides a potential new Achilles heel for guiding combination therapies in humans.
2017-01-12 | GSE83671 | GEO
Project description:Aberrant enhancer activation is a key mechanism driving oncogene expression in many cancers. While much is known about the regulation of larger chromosome domains in eukaryotes, the details of enhancer-promoter interactions remain poorly understood. Recent work suggests co-activators like BRD4 and Mediator have little impact on enhancer-promoter interactions. In leukemias controlled by the MLL-AF4 fusion protein, we use the ultra-high resolution technique Micro-Capture-C (MCC) to show that MLL-AF4 binding promotes broad, high-density regions of enhancer-promoter interactions at a subset of key targets. These enhancers are enriched for transcription elongation factors like PAF1C and FACT and loss of these factors abolishes enhancer-promoter contact. This work not only provides a new model for how MLL-AF4 is able to drive high levels of transcription at key genes in leukemia, but also suggests a more general model linking enhancer-promoter crosstalk and transcription elongation.
2023-08-18 | PXD043920 | Pride
Project description:MLL-AF4 is a hallmark genomic aberration which arises prenatally in high-risk infant acute lymphoblastic leukemia (ALL). In human embryonic stem cells (hESCs), MLL-AF4 skewed hemato-endothelial specification but was not sufficient for transformation. Additional cooperating genetic insults seem required for MLL-AF4-mediated leukemogenesis. FLT3 is highly expressed in MLL-AF4+ ALL through activating mutations (FLT3-TKD or FLT3-ITD) or increased transcriptional expression, being therefore considered a potential cooperating event in MLL-AF4+ ALL. Here, we explored the developmental impact of FLT3 activation on its own or in cooperation with MLL-AF4 in the hematopoietic fate of hESCs. FLT3 activation did not impact specification of CD45-CD31+ hemogenic precursors but significantly enhanced the formation of CD45+CD34+ and CD45+ blood cells and blood progenitors with clonogenic potential. Importantly, FLT3 activation through FLT3 mutations or FLT3-WT overexpression completely abrogated hematopoietic differentiation from MLL-AF4-expressing hESCs, indicating that FLT3 activation cooperates with MLL-AF4 to inhibit human embryonic hematopoiesis. Cell cycle/apoptosis analyses suggest that FLT3 activation directly impacts hESC specification rather than selective proliferation/survival of hESC-emerging hematopoietic derivatives. Transcriptional profiling supported the limited impact of FLT3 activation on hESC specification towards CD45-hemogenic precursors and the enhanced hematopoiesis upon FLT3 activation, and inhibited hematopoiesis upon MLL-AF4 expression in FLT3-activated hESCs which was associated to large transcriptional changes and regulation of master early hematopoietic genes. Also, although FLT3 activation and MLL-AF4 cooperate to inhibit embryonic hematopoiesis the underlying molecular/genetic mechanisms differ depending on how FLT3 activation is achieved. Finally, FLT3 activation did not cooperate with MLL-AF4 to immortalize/transform hESC-derived hematopoietic cells. 18 samples were analyzed. CD45- hemogenic precursors EV, 2 biological rep CD45- hemogenic precursors FLT3-TKD, 2 biological rep CD45- hemogenic precursors FLT3-WT, 2 biological rep CD45- hemogenic precursors FLT3-TKD/MLLAF4, 2 biological rep CD45- hemogenic precursors FLT3-WT/MLLAF4, 2 biological rep CD45+ blood cells EV, 1 biological rep CD45+ blood cells FLT3-TKD, 2 biological rep CD45+ blood cells FLT3-WT, 2 biological rep CD45+ blood cells FLT3-TKD/MLLAF4, 2 biological rep CD45+ blood cells FLT3-WT/MLLAF4, 1 biological rep
2013-06-04 | E-GEOD-40103 | biostudies-arrayexpress
Project description:The Mixed Lineage Leukemia 1 protein (MLL1) is an important epigenetic regulator required for the maintenance of gene activation during development. MLL1 chromosome translocations produce novel fusion proteins that cause aggressive leukemias in humans. Individual MLL1 fusion proteins have distinct leukemic phenotypes even when expressed in the same cell type, but how this distinction is delineated on a molecular level is poorly understood. Here we highlight a unique molecular mechanism whereby MLL-AF4 specifically activates the RUNX1 gene and the RUNX1 protein interacts with the product of the reciprocal AF4-MLL translocation. These results support a mechanism of leukemic growth whereby two oncogenic fusion proteins cooperate by activating a target gene and then interacting directly with its downstream product ChIP-seq using RUNX1 antibody in SEM cells
2013-01-31 | E-GEOD-42075 | biostudies-arrayexpress