PHF6 Interacts with LMO2 During Normal Haematopoiesis and in Leukaemia and Regulates the Level of Gene Expression and Genome Integrity
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA646993 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:The transcriptional mediator LIM domain only 2 (LMO2) forms a large multi-protein complex together with TAL1/LYL1, HEB/E2A, LDB1 and GATA. This complex regulates transcription from the onset of haematopoietic development and during differentiation. Chromosomal re-arrangements involving LMO and other members of the complex are causative for T-cell lymphoblastic leukaemia (T-ALL). We have identified Plant Homeodomain (PHD)-like Finger 6 (PHF6) as a new LMO2 interacting factor. Somatic mutations in PHF6 have been found to occur in several types of leukaemia. We show that PHF6 interacts with LMO2 during the initial stages of the haematopoietic development, myeloid differentiation and in T-ALL. The LMO2/PHF6 complex binds the DNA and regulates linage-specific gene expression. Additionally, a loss or reduction of LMO2 and PHF6 leads to chromosomal instability. PHF6 and LMO2 are required for maintaining levels of γH2AX and 53BP1, where PHF6 is important for γH2AX accumulation and LMO2 has a role in recruiting 53BP1 to γH2AX foci.
2024-12-31 | GSE154675 | GEO
Project description:Cellular differentiation-trajectories require extensive alterations in chromatin structure and function, elicited by a diverse array of chromatin-factors (CFs). Using haematopoiesis as a model-system, we combined bulk ex vivo and single-cell in vivo CRISPR screens to comprehensively characterise the role of CF families in cell-fate decisions. We uncover marked lineage specificities for many CFs, dissecting specific CF-dependencies in vivo at single-cell resolution. This highlights functional diversity among related CFs (i.e. BAF-subcomplexes, MLL-methyltransferases), but also reveals functional redundancy among unrelated Repressive-complexes that restrain excessive myeloid differentiation. Epigenetic-profiling, molecularly explains CF lineage-dependencies, identifying differentiation stage-specific interactions between individual CFs and lineage-determining Transcription Factors (TFs). Intriguingly, non-canonical BAF remodeler disruption abrogates myeloid-TF function generating a pre-leukaemia phenotype. Screening CF functions in leukemia, we show that leukaemia cells abrogate normal CF function, restraining differentiation trajectories by engaging in novel CF-TF interactions that suggest potential therapeutic avenues. Together, our work greatly elucidates the role of CFs and their TF-partners across normal and malignant haematopoiesis.
2023-05-23 | GSE213511 | GEO
Project description:T-cell Acute Lymphoblastic Leukaemia (T-ALL) can be classified into a number of subfamilies, including those that overexpress TAL1/LMO, TLX1/3 and HOXA transcription factors. Whilst it has been previously shown in mouse models that TAL1/LMO transcription factors induce thymocyte self-renewal, whether this is the case for other transcription factor subclasses is currently unknown. To address this, we have studied vav-Nup98-HoxD13-transgenic (NHD13-Tg) mice, a model of HOXA-driven T-ALL, which overexpress HOXA transcription factors throughout haematopoiesis and display features of myelodysplastic syndrome in the bone marrow along with T-cell developmental abnormalities in the thymus and subsequent development of T-ALL in approximately 15% of mice. Thymocytes from preleukemic NHD13-Tg mice could engraft long-term in serial transplantation assays, demonstrating that NHD13-Tg thymocytes have acquired self-renewal capacity. Transcriptome analysis showed that NHD13-Tg thymocytes exhibited a Stem Cell like transcriptional program which closely resembled that of Lmo2 transgenic thymocytes, including Lmo2 itself and the critical Lmo2 cofactor Lyl1, suggesting a common mechanism of thymocyte self-renewal in these models. To determine whether Lmo2/Lyl1 are required for NHD13-induced thymocyte self-renewal, NHD13-Tg mice were crossed with Lyl1 knockout mice to generate NHD13-Tg mice lacking Lyl1. This showed that Lyl1 is essential for expression of the stem cell-like gene expression program in NHD13-Tg thymocytes and for thymocyte self-renewal. Surprisingly however, absence of Lyl1 accelerated the onset of T-ALL in NHD13-Tg mice. These studies demonstrate that Lyl1 is essential for self-renewal of NHD13-Tg thymocytes, suggesting that Lmo2 and Lyl1 may mediate thymocyte self-renewal induced by a variety of T-cell oncogenes. However, whilst Lyl1-induced thymocyte self-renewal is essential for Lmo2-driven T-cell leukemia, NHD13 can also promote T-ALL via an alternative pathway.
2019-03-04 | GSE121641 | GEO
Project description:Post-transcriptional mechanisms are fundamental safeguards of progenitor cell identity and are often dysregulated in cancer. Here, we identified regulators of P-bodies as crucial vulnerabilities in acute myeloid leukaemia (AML) through genome-wide CRISPR screens in normal and malignant haematopoietic progenitors. We found that leukaemia cells harbour aberrantly elevated numbers of P-bodies and show that P-body assembly is crucial for initiation and maintenance of AML. Notably, P-body loss had little effect upon homoeostatic haematopoiesis but impacted regenerative haematopoiesis. Molecular characterization of P-bodies purified from human AML cells unveiled their critical role in sequestering messenger RNAs encoding potent tumour suppressors from the translational machinery. P-body dissolution promoted translation of these mRNAs, which in turn rewired gene expression and chromatin architecture in leukaemia cells. Collectively, our findings highlight the contrasting and unique roles of RNA sequestration in P-bodies during tissue homoeostasis and oncogenesis. These insights open potential avenues for understanding myeloid leukaemia and potential therapeutic interventions.
2024-08-08 | GSE224643 | GEO
Project description:Post-transcriptional mechanisms are fundamental safeguards of progenitor cell identity and are often dysregulated in cancer. Here, we identified regulators of P-bodies as crucial vulnerabilities in acute myeloid leukaemia (AML) through genome-wide CRISPR screens in normal and malignant haematopoietic progenitors. We found that leukaemia cells harbour aberrantly elevated numbers of P-bodies and show that P-body assembly is crucial for initiation and maintenance of AML. Notably, P-body loss had little effect upon homoeostatic haematopoiesis but impacted regenerative haematopoiesis. Molecular characterization of P-bodies purified from human AML cells unveiled their critical role in sequestering messenger RNAs encoding potent tumour suppressors from the translational machinery. P-body dissolution promoted translation of these mRNAs, which in turn rewired gene expression and chromatin architecture in leukaemia cells. Collectively, our findings highlight the contrasting and unique roles of RNA sequestration in P-bodies during tissue homoeostasis and oncogenesis. These insights open potential avenues for understanding myeloid leukaemia and potential therapeutic interventions.
2024-08-08 | GSE260919 | GEO
Project description:We differentiated WT, LMO2KO or TAL1 KO mouse ES cell lines into Flk-1+ haemangioblasts and/or Tie2+;Kit+;CD41- haemogenic endothelium 1 (HE1). We performed RNAseq, ChIPseq and/or DHS seq on these cells and compared the samples. Our study showed that Lmo2-/- embryonic stem cells differentiated less efficiently to haemogenic endothelium, which only produced primitive haematopoietic progenitors. LMO2 was required at the haemangioblast stage to position the TAL1/LMO2/LDB1 complex to regulatory elements that are important for the establishment of the haematopoietic developmental program. In the absence of LMO2, TAL1 protein levels were low and the target site recognition of TAL1 was impaired.
2017-11-01 | GSE99938 | GEO
Project description:Here we identify the genome-wide occupancy of PHF6 in T-ALL cells. Human T-ALL cells were cross-linked with formaldehyde for 20 min. DNA was enriched by chromatin immunoprecipitation (ChIP) and analyzed by Solexa sequencing. A sample of whole cell extract (WCE) was sequenced and used as the background to determine enrichment. ChIP was performed using an antibody against total PHF6 (Bethyl A301-451A). This represents the ChIP-seq portion of this dataset.
2014-04-01 | E-GEOD-45864 | biostudies-arrayexpress
Project description:Loss-of-function mutations Phf6 occur frequently in both adult and pediatric T-cell Acute Lymphoblastic Leukemia (T-ALL). Although Phf6 is widely expressed, little is known about its proposed function as epigenetic regulator and tumor suppressor. To address the role of Phf6 in the leukemia development, here we analyze by RNAseq the gene expression profiles of isogenic Phf6 wild type and Phf6 knockout leukemia cells transformed by overexpression of an oncogenic mutant form of the NOTCH1 receptor.
2019-07-31 | GSE117165 | GEO
Project description:Lmo2 is an oncogenic transcription factor that is a frequent target of chromosomal abnormalities in this T-cell acute lymphoblastic leukemia (T-ALL). In transgenic mouse models, overexpression of Lmo2 causes thymocyte self-renewal leading to T-cell leukemia with long latency. However, the requirement of Lmo2 for maintenance of overt leukemia is poorly understood. We found that Lyl1, a critical cofactor for Lmo2-induced leukemia, is frequently lost in cell lines derived from Lmo2-transgenic mice, raising the possibility that Lmo2 function is dispensable at this stage. To study this, we developed a Tetracycline-repressible knock-in mouse model (Vav-TRE-Lmo2), which expresses Lmo2 throughout the haematopoietic system. This led to specific effects on T-cell development and the development of T-cell leukemia with long latency, preceded by the presence of self-renewing T-cells in the thymus. Repression of Lmo2 overcame the Lmo2-induced thymocyte developmental block at the preleukemic stage and led to elimination of Lmo2-induced thymocyte self-renewal in vivo. In contrast, Lmo2 function was dispensable for the majority of overt Lmo2-induced T-cell leukemias as well as leukemia-derived cell lines, implying an evolution of oncogene addiction in the majority of T-cell leukemias. Lmo2-dependence in T-ALL was associated with an immature gene expression profile, but could not be predicted by immunophenotype or assessment of Notch pathway activation. Thus, Lmo2 can give rise to both Lmo2-depenent and –independent T-cell leukemias. The Vav-TRE-Lmo2 model should be useful to determine the molecular features associated with Lmo2-dependence, as well as the critical components of the Lmo2-induced self-renewal pathways in T-ALL.
2022-01-01 | GSE125674 | GEO
Project description:Systematic screening of chromatin factors identifies divergent roles across haematopoiesis and leukaemia [scRNA-Seq]
| PRJNA881278 | ENA