Deletion of the Hoxa Cluster in MLL-AF9 Is Incompatible with Leukemia Maintenance: RNAseq-based Quantitative Analysis of Wild Type and Hoxa-del Transcriptomes
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ABSTRACT:
PROVIDER: PRJNA450411 | ENA |
REPOSITORIES: ENA
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Project description:High HOXA expression correlates with poor clinical outcome in AML, particularly those harboring MLL rearrangements (MLLr). The necessity of the HOXA cluster for the maintenance of MLLr-leukemia has not been elucidated. Primary leukemias were generated by transduction of MLL-AF9 (MA9) into hematopoietic stem and progenitor cells from compound Cre responsive transgenic mice for conditional deletion of the Hoxa locus. Hoxa deletion resulted in reduced proliferation, colony formation and repopulating ability in transplanted mice in which surviving leukemic cells retained at least one copy of the Hoxa cluster (Hoxa-del). Comparative RNA-seq analysis of leukemic MA9-Hoxa-wild type (WT) and MA9-Hoxa-del cells identified a unique gene signature.
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Project description:HOXA9 and MEIS1 are essential downstream effectors of the MLL-AF9 oncoprotein during leukaemia induction. Leukaemia derived from MLL-AF9-transduced LSK cells has a more aggressive phenotype than that derived from HOXA9/MEIS1-transduced LSK cells. To determine differential gene expression that contributes to increased aggressiveness in MLL-AF9-induced leukaemia, microarray was performed on LSK cells transduced with MLL-AF9 versus HOXA/MEIS1 oncogenes.
2019-07-03 | E-MTAB-7355 | biostudies-arrayexpress
Project description:HOXA9 and MEIS1 are essential downstream effectors of the MLL-AF9 oncoprotein during leukemia induction. Leukemia derived from MLL-AF9-transduced LSK cells has a more aggressive phenotype than that derived from HOXA9/MEIS1-transduced LSK cells. To determine differential miRNA expression that contributes to increased aggressiveness in MLL-AF9-induced leukemia, miRCURY LNA microRNA Array was performed on LSK cells transduced with MLL-AF9 versus HOXA/MEIS1 oncogenes.
2019-07-03 | E-MTAB-7356 | biostudies-arrayexpress
Project description:MIR139 is a critical tumor suppressor and commonly silenced in human cancer, including acute myeloid leukemia (AML). Here, we found that depletion of identified MIR139 targets affects AML outgrowth. We unraveled the mechanism of MIR139 gene inactivation in AML expressing the Mixed-Lineage Leukemia (MLL)-AF9 oncogene. Epigenetic analyses revealed two well-conserved putative enhancer regions in close proximity of transcriptional start sites (TSS) of MIR139. These regions were silenced by the Polycomb-Repressive Complex-2 (PRC2) downstream of MLL-AF9. Genomic deletion of these regions abolished MIR139 transcriptional regulation in normal and oncogenic conditions. Genome-wide knockout screens revealed the transcriptional pausing factor of RNA Polymerase-II, POLR2M, as a critical MIR139-silencing factor. Furthermore, direct POLR2M binding to the MIR139 TSS induced paused transcription, which was abrogated upon PRC2 inhibition. We present evidence for an oncogenic POLR2M-mediated MIR139 silencing mechanism, downstream of MLL-AF9 and PRC2. Together, our findings highlight the importance of POLR2M-mediated paused transcription in AML.
2021-11-11 | PXD022488 | Pride
Project description:A t(9;11)(p22;q23) translocation produces the MLL-AF9 fusion protein, which is found in up to 25% of de novo AML cases in children. Despite major advances, obtaining a comprehensive under-standing of context-dependent MLL-AF9-mediated gene programs during early hematopoiesis is challenging. Here, we generated a human inducible pluripotent stem cell (hiPSC) model with a doxycycline dose-dependent MLL-AF9 expression. We exploited MLL-AF9 expression as an onco-genic hit to uncover epigenetic and transcriptomic effects on iPSC-derived hematopoietic develop-ment and the transformation into (pre-)leukemic states. In doing so, we observed a disruption in early myelomonocytic development. Accordingly, we identified gene profiles that were consistent with primary MLL-AF9 AML and uncovered high-confidence MLL-AF9-associated core genes that are faithfully represented in primary MLL-AF9 AML, including known and presently unknown factors. Using single-cell RNA-sequencing, we identified an increase of CD34 expressing early hematopoietic progenitor-like cell states as well as granulocyte-monocyte progenitor-like cells upon MLL-AF9 activation. Our system allows for careful chemically controlled and stepwise in vitro hiPSC-derived differentiation under serum-free and feeder-free conditions. For a disease that cur-rently lacks effective precision medicine, our system provides a novel entry-point into exploring po-tential novel targets for personalized therapeutic strategies.
2023-05-03 | GSE217014 | GEO
Project description:To explore oncogene addiction programs in a genetically defined leukemia context we developed an AML mouse model driven by a conditional MLL-AF9 allele together with oncogenic Ras, which enabled us to examine the consequences of MLL-AF9 inhibition in established disease. In order to produce a tightly regulated system that was easy to monitor, we constructed two retroviral vectors containing dsRed-linked MLL-AF9 under control of a tetracycline response element promoter, and KrasG12D or NrasG12D linked to the “Tet-off” tet-transactivator, which activates TRE expression in a doxycycline repressible manner. Leukemias were generated by retroviral cotransduction of both vectors into hematopoietic stem and progenitor cells, which were transplanted into syngeneic mice. Cells harboring both constructs induced aggressive myelomonocytic leukemia. Five independent primary leukemia cell lines were established from bone marrow of terminal mice. Treatment of these lines with doxycycline rapidly turned off MLL-AF9 expression, and induced terminal myeloid differentiation and complete disease remission in vivo. To identify molecular mechanisms underlying addiction to MLL-AF9, we analyzed global gene expression changes following doxycycline-induced suppression of MLL-AF9. Independent primary acute myeloid leukemia lines induced by cotransduction of Tet-off MLL-AF9 together with either KrasG12D or NrasG12D were grown in culture and treated with doxycycline for 6 days to inactivate MLL-AF9 expression. In addition, primary acute myeloid leukemia lines with constitutive MLL-AF9 and KrasG12D were included to control for the effects of doxycycline. Untreated and treated cells were harvested for RNA extraction and hybridization to Affymetrix arrays.
2011-08-04 | E-GEOD-30746 | biostudies-arrayexpress
Project description:To explore oncogene addiction programs in a genetically defined leukemia context we developed an AML mouse model driven by a conditional MLL-AF9 allele together with oncogenic Ras, which enabled us to examine the consequences of MLL-AF9 inhibition in established disease. In order to produce a tightly regulated system that was easy to monitor, we constructed two retroviral vectors containing dsRed-linked MLL-AF9 under control of a tetracycline response element promoter, and KrasG12D or NrasG12D linked to the “Tet-off” tet-transactivator, which activates TRE expression in a doxycycline repressible manner. Leukemias were generated by retroviral cotransduction of both vectors into hematopoietic stem and progenitor cells, which were transplanted into syngeneic mice. Cells harboring both constructs induced aggressive myelomonocytic leukemia. Five independent primary leukemia cell lines were established from bone marrow of terminal mice. Treatment of these lines with doxycycline rapidly turned off MLL-AF9 expression, and induced terminal myeloid differentiation and complete disease remission in vivo. To identify molecular mechanisms underlying addiction to MLL-AF9, we analyzed global gene expression changes following doxycycline-induced suppression of MLL-AF9.
2011-08-05 | GSE30746 | GEO
Project description:Using an acute myeloid leukemia (AML) mouse model driven by tet-regulated MLL-AF9 (fusion between the gene MLL1 (KMT2A/MLL) and MLLT3 (AF9)) co-expressed with oncogenic NRASG12D (Tet-off MLL-AF9), we investigated the effect of modulating the expression of the MLL-AF9 fusion oncogene on the transcriptome and proteome of established murine AML. Treatment in vitro or in vivo of these Tet-off MLL-AF9 AMLs with doxycycline (DOX) results in the efficient down-regulation of the expression of the driver oncogene MLL-AF9. RNA sequencing analysis was performed on primary Tet-Off MLL-AF9 AML cells obtained from the spleen of leukemic animals and cultured in vitro for either 2 or 4 days in the presence of doxycycline (1μg/ml) (DOX= down-regulation of MLL-AF9) or left untreated (UT).
2021-12-31 | GSE108326 | GEO
Project description:We investigated the role of the transcriptional regulator Id2 in the context of MLL-rearranged acute myeloid leukemia (AML). Using an AML mouse model driven by tet-regulated MLL-AF9 co-expressed with oncogenic NRASG12D (Tet-off MLL-AF9), we demonstrated that MLL-AF9 regulates the E protein pathway by suppressing Id2, while activating the expression of its target E2-2. Moreover, we found that Id2 over-expression in Tet-Off MLL-AF9 AML cells in vitro partially phenocopies MLL-AF9 depletion and results inhibition of leukemia growth, loss of leukemia stem cell-associated gene expression pattern and induction of differentiation. To compare gene expression changes associated with enforced Id2 expression and MLL-AF9 withdrawal, RNA sequencing analysis was performed on Tet-off MLL-AF9 cells transduced with an Id2 over-expressing or a control vector, or upon MLL-AF9 dox-inducible knock-down.
2016-06-29 | GSE68462 | GEO
Project description:We investigated the role of the transcriptional regulator Id2 in the context of MLL-rearranged acute myeloid leukemia (AML). Using an AML mouse model driven by tet-regulated MLL-AF9 co-expressed with oncogenic NRASG12D (Tet-off MLL-AF9), we demonstrated that MLL-AF9 regulates the E protein pathway by suppressing Id2, while activating the expression of its target E2-2. Moreover, we found that Id2 over-expression in Tet-Off MLL-AF9 AML cells in vitro partially phenocopies MLL-AF9 depletion and results inhibition of leukemia growth, loss of leukemia stem cell-associated gene expression pattern and induction of differentiation. To compare gene expression changes associated with enforced Id2 expression and MLL-AF9 withdrawal, RNA sequencing analysis was performed on Tet-off MLL-AF9 cells transduced with an Id2 over-expressing or a control vector, or upon MLL-AF9 dox-inducible knock-down. Primary AMLs driven by Tet-off inducible MLL/AF9 expression linked to dsRED reporter, in association with oncogenic NRASG12D (Tet-off MLL-AF9) were generated by reconstituting lethally irradiated congenic mice with foetal liver cells co-transduced with a Tet-Off-MLL-AF9-dRED retroviral vector and a second vector co-expressing NRASG12D together with the Tet-Off responsive transcriptional activator. RNA sequencing analysis sequencing analysis was performed on Tet-Off MLL-AF9/dsRED+ AML cells treated in vitro with doxycycline (DOX) for 4 days to inactivate MLL-AF9 expression or left untreated (UT). For the Id2 over-expression experiment, Tet-Off MLL-AF9/dsRED+ AML cells were transduced in vitro with an Id2-GFP or a control-GFP retroviral vector. Viable GFP-positive cells were FACS-sorted 2 days after transduction and used for RNA sequencing analysis.
2016-06-29 | E-GEOD-68462 | biostudies-arrayexpress