Gene expression signature of HoxA9-Meis1 AML cells treated with Pyrydopyrazine
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ABSTRACT: Pyrydopyrazine A2 induced in vitro the differentiation of leukemic cells (HoxA9-Meis1) into macrophages, we decided to perform a transcriptomic study in order to analyze the GM-CSF pathway regulation. We therefore compared effect with A2 to cells treated with Retinoic acid and D3 Vitamin, a combination known to induce also differentiation of leukemic cells. HoxA9-Meis1 murine AML cells were treated in vitro during 24h, with Pyrydopyrazine( A2) at 3.4μM or a combination of all-trans Retinoic Acid (RA) and 1α-hydroxy-D3 Vitamin (D3V), 10μM each. Gene expression signature was compared to untreated control. One sample was tested for each condition
Project description:Pyrydopyrazine A2 induced in vitro the differentiation of leukemic cells (HoxA9-Meis1) into macrophages, we decided to perform a transcriptomic study in order to analyze the GM-CSF pathway regulation. We therefore compared effect with A2 to cells treated with Retinoic acid and D3 Vitamin, a combination known to induce also differentiation of leukemic cells.
Project description:The clustered homeobox proteins play crucial roles in development, hematopoiesis and leukemia yet the targets they regulate and their mechanisms of action are poorly understood. Here, we identified the binding sites for Hoxa9 and the Hox cofactor Meis1 on a genome-wide level and profiled their associated epigenetic modifications and transcriptional targets. Hoxa9 and the Hox cofactor Meis1 co-bind at hundreds of highly evolutionarily-conserved sites, most of which are distant from transcription start sites. These sites show high levels of histone H3K4 monomethylation and CBP/P300 binding characteristic of enhancers. Furthermore, a subset of these sites shows enhancer activity in transient transfection assays. Many Hoxa9 and Meis1 binding sites are also bound by PU.1 and other lineage-restricted transcription factors previously implicated in establishment of myeloid enhancers. Conditional Hoxa9 activation is associated with CBP/P300 recruitment, histone acetylation and transcriptional activation of a network of proto-oncogenes including Erg, Flt3, Lmo2, Myb and Sox4. Collectively this work suggests that Hoxa9 regulates transcription by interacting with enhancers of genes important for hematopoiesis and leukemia. To identify the genome-wide binding sites for Hoxa9 and the Hox cofactor Meis1
Project description:JMJD1C, a Jumonji C (JmjC) domain-containing histone demethylase, has been reported as a direct cofactor of oncogenic transcription factor HOXA9. To identify JMJD1C downstream effectors, we performed a genome-wide gene expression profiling experiment. Our microarray analysis identified a new role for JMJD1C in regulating a cancer metabolic program in HOX-driven AML. GFP+ HOXA9/MEIS1-mediated pre-leukemic stem cells were transduced with retroviruses carrying JMJD1C or empty vector for the microarray experiment. Each group has 4 samples.
Project description:YTHDF2 is overexpressed in a broad spectrum of human acute myeloid leukemias (AML). To study the role of YTHDF2 in leukemia, c-Kit+ cells from foetal livers of Ythdf2fl/fl;Vav-iCre (Ythdf2CKO) and Ythdf2fl/fl (Ythdf2CTL) 14.5 dpc embryos were transduced with Meis1 and Hoxa9 oncogenes and serially re-plated to generate pre-leukemic cells. Total RNA from Ythdf2CKO (n=5) and Ythdf2CTL (n=5) pre-leukemic cells were used for Affymetrix global gene expression analysis.
Project description:Total bone marrow (BM) from miR-223 knockout (mir-223-/-) and wildtype (miR-223+/+) mice 21 was extracted, prestimulated for 2 days. Then, the BM cells were simultaneously cotransduced with MSCV-Hoxa9-pgk-neomycin and a MSCV-Meis1-IRES-YFP by co-cultivation with irradiated (4,000 cGy) viral producers. HoxA9-Meis1 transduced cells were sorted for YFP expression and continuously selected with neomycin (1.4 mg/ml). Processing of the pre-miRNA through Dicer1 generates a miRNA duplex, consisting of a miRNA and miRNA* strand. Despite the general view that miRNA*s have no functional role, we further investigated miRNA* species in 10 deep sequencing libraries from mouse and human tissue. Comparing miRNA/miRNA* ratios across the miRNA sequence libraries revealed that 50% of the investigated miRNA duplexes exhibit a highly dominant strand. Conversely, 10% of miRNA duplexes show a comparable expression of both strands, while the remaining 40% exhibit variable ratios across the examined libraries as exemplified by miR-223/miR-223* in murine and human cell lines. Functional analyses revealed a regulatory role for miR-223* in myeloid progenitor cells, implying an active role for both arms of the miR-223 duplex. This was further underscored by the demonstration that miR-223 and miR-223* target the IGF1R/PIK3 axis and that high miR-223* levels associate with increased overall survival in acute myeloid leukemia (AML) patients. Thus, we found a supporting role for miR-223* in differentiating myeloid cells in normal as well as the leukemic cell state. The fact that the miR-223 duplex acts through both arms extends the complexity of miRNA-directed gene regulation of this myeloid key miRNA. 2 biological replicates
Project description:The clustered homeobox proteins play crucial roles in development, hematopoiesis and leukemia yet the targets they regulate and their mechanisms of action are poorly understood. Here, we identified the binding sites for Hoxa9 and the Hox cofactor Meis1 on a genome-wide level and profiled their associated epigenetic modifications and transcriptional targets. Hoxa9 and the Hox cofactor Meis1 co-bind at hundreds of highly evolutionarily-conserved sites, most of which are distant from transcription start sites. These sites show high levels of histone H3K4 monomethylation and CBP/P300 binding characteristic of enhancers. Furthermore, a subset of these sites shows enhancer activity in transient transfection assays. Many Hoxa9 and Meis1 binding sites are also bound by PU.1 and other lineage-restricted transcription factors previously implicated in establishment of myeloid enhancers. Conditional Hoxa9 activation is associated with CBP/P300 recruitment, histone acetylation and transcriptional activation of a network of proto-oncogenes including Erg, Flt3, Lmo2, Myb and Sox4. Collectively this work suggests that Hoxa9 regulates transcription by interacting with enhancers of genes important for hematopoiesis and leukemia. Enriched Hoxa9 and Meis1 regions and a selected set of the nearest 360 TSSs were tiled onto Nimblegen custom arrays (Mus musculus 8, Feb 2006) with 50-mer probes (average spacing of 35bp), along with 60 negative control sequences that were selected randomly from the mouse genome
Project description:Characterization of gene expression changes 72 hours after withdrawal of tamoxifen in murine hematopoietic progenitors transformed by Hoxa9-ER/Meis1 using RNAseq. In the presence of tamoxifen (4OHT), Hoxa9-ER localizes to the nucleus of cells allowing for transformation, while withdrawal of 4OHT (culture in EtOH) leads to loss of nuclear Hoxa9-ER. Loss of Hoxa9-ER leads to a decrease in cellular proliferation and differentiation along the myeloid lineage. Examination of gene expression by RNAseq in two conditions in biological replicates.
Project description:The mRNA m6A reader YTHDF2 is overexpressed in a broad spectrum of human acute myeloid leukemias (AML). To study the role of YTHDF2 on mRNA decay rates in leukemia, c-Kit+ cells from foetal livers of Ythdf2fl/fl; Vav-iCre (Ythdf2CKO) and Ythdf2fl/fl (Ythdf2CTL) 14.5 dpc embryos were transduced with Meis1 and Hoxa9 oncogenes and serially re-plated to generate pre-leukemic cells. Medium with 4SU was used for pre-leukemic cells labelling for 12 hours and was later replaced with 4SU-free medium (time 0). Cells were collected immediately after medium change and at 1, 3 and 9 hours for library generation. RNA from Ythdf2CKO (n=3 biological replicates) and Ythdf2CTL (n=3 biological replicates) pre-leukemic cells were used for SLAM-seq library generation.
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.
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.