Similar Datasets
Project description:Transcriptional dysregulation is a prominent feature in leukemia. Here, we systematically surveyed transcription factor (TF) vulnerabilities in leukemia and uncovered TF clusters that exhibit context-specific vulnerabilities within and between different subtypes of leukemia. Among these TF clusters, we demonstrated that acute myeloid leukemia (AML) with high IRF8 expression was addicted to MEF2D. MEF2D and IRF8 form an autoregulatory loop via direct binding to mutual enhancer elements. One important function of this circuit in AML is to sustain PU.1/MEIS1 co-regulated transcriptional outputs via stabilizing PU.1's chromatin occupancy. We illustrated that AML could acquire dependency on this circuit through various oncogenic mechanisms that results in the activation of their enhancers. In addition to forming a circuit, MEF2D and IRF8 can also separately regulate gene expression, and dual perturbation of these two TFs leads to a more robust inhibition of AML proliferation. Collectively, our results revealed a TF circuit essential for AML survival.
| S-EPMC9526175 | biostudies-literature
Project description:Transcriptional dysregulation is a prominent feature in leukemia. Here, we systematically surveyed the transcription factor (TF) vulnerabilities in leukemia, and uncovered TF clusters that exhibit context-specific addictions within and between different subtypes of leukemia. We focused on and validated MEF2D as a requirement exclusively in AML with high IRF8 expression. Transcriptomic and chromatin-binding profiling revealed a key TF circuit composed of MEF2D-IRF8 vital for AML maintenance. AML can acquire dependence on this circuit through various mechanisms, including enhancer activation of the circuit via MLL-rearrangement. IRF8 cooperates with PU.1 to control PU.1/MEIS1 co-regulated transcriptional outputs, meanwhile coordinating with MEF2D to directly regulate genes in a non-redundant manner. Collectively, our study nominates a TF circuit in support of the pathogenesis of AML.
2022-09-07 | GSE186130 | GEO
Project description:Transcriptional dysregulation is a prominent feature in leukemia. Here, we systematically surveyed the transcription factor (TF) vulnerabilities in leukemia, and uncovered TF clusters that exhibit context-specific addictions within and between different subtypes of leukemia. We focused on and validated MEF2D as a requirement exclusively in AML with high IRF8 expression. Transcriptomic and chromatin-binding profiling revealed a key TF circuit composed of MEF2D-IRF8 vital for AML maintenance. AML can acquire dependence on this circuit through various mechanisms, including enhancer activation of the circuit via MLL-rearrangement. IRF8 cooperates with PU.1 to control PU.1/MEIS1 co-regulated transcriptional outputs, meanwhile coordinating with MEF2D to directly regulate genes in a non-redundant manner. Collectively, our study nominates a TF circuit in support of the pathogenesis of AML.
2022-09-07 | GSE186129 | GEO
Project description:Dissection of the MEF2D-IRF8 transcriptional circuit dependency in acute myeloid leukemia
| PRJNA772709 | ENA
Project description:Dissection of the MEF2D-IRF8 transcriptional circuit dependency in acute myeloid leukemia [ChIP-seq]
| PRJNA772712 | ENA
Project description:Dissection of the MEF2D-IRF8 transcriptional circuit dependency in acute myeloid leukemia [CUT&RUN]
| PRJNA772714 | ENA
Project description:Hundreds of genes become aberrantly silenced in acute myeloid leukemia (AML), with most of these epigenetic changes being of unknown functional consequence. Here, we demonstrate how gene silencing can lead to an acquired dependency on the DNA repair machinery in AML. We make this observation by profiling the essentiality of the ubiquitination machinery in cancer cell lines using domain-focused CRISPR screening, which revealed Fanconi anemia (FA) proteins UBE2T and FANCL as unique dependencies in AML. We demonstrate that these dependencies are due to a synthetic lethal interaction between FA proteins and aldehyde dehydrogenase 2 (ALDH2), which function in parallel pathways to counteract the genotoxicity of endogenous aldehydes. We show DNA hypermethylation and silencing of ALDH2 occur in a recurrent manner in human AML, which is sufficient to confer FA pathway dependency. Our study suggests that targeting of the ubiquitination reaction catalyzed by FA proteins can eliminate ALDH2-deficient AML. SIGNIFICANCE: Aberrant gene silencing is an epigenetic hallmark of human cancer, but the functional consequences of this process are largely unknown. In this study, we show how an epigenetic alteration leads to an actionable dependency on a DNA repair pathway through the disabling of genetic redundancy.This article is highlighted in the In This Issue feature, p. 2113.
| S-EPMC8419016 | biostudies-literature
Project description:The cellular context that integrates gene expression, signaling, and metabolism dictates the oncogenic behavior and shapes the treatment responses in distinct cancer types. Although chimeric fusion proteins involving transcription factors (TF) are hallmarks of many types of acute lymphoblastic leukemia (ALL), therapeutically targeting the fusion proteins is a challenge. In this work, we characterize the core regulatory circuitry (CRC; interconnected autoregulatory loops of TFs) of B-ALL involving MEF2D-fusions and identify MEF2D-fusion and SREBF1 TFs as crucial CRC components. By gene silencing and pharmacologic perturbation, we reveal that the CRC integrates the pre-B-cell receptor (BCR) and lipid metabolism to maintain itself and govern malignant phenotypes. Small-molecule inhibitors of pre-BCR signaling and lipid biosynthesis disrupt the CRC and silence the MEF2D fusion in cell culture and show therapeutic efficacy in xenografted mice. Therefore, pharmacologic disruption of CRC presents a potential therapeutic strategy to target fusion protein-driven leukemia.SignificanceCancer type-specific gene expression is governed by transcription factors involved in a highly interconnected autoregulatory loop called CRC. Here, we characterized fusion protein-driven CRC and identified its pharmacologic vulnerabilities, opening therapeutic avenues to indirectly target fusion-driven leukemia by disrupting its CRC.See related commentary by Sadras and Müschen, p. 18. This article is highlighted in the In This Issue feature, p. 5.
| S-EPMC8447276 | biostudies-literature
Project description:Acute myeloid leukemia (AML) with MLL-rearrangement (MLL-r) comprises ∼10% of all AML cases and portends poor outcomes. Much remains uncovered on how MLL-r AML drives leukemia development while preventing cells from normal myeloid differentiation. Here, we identified that transcription factor MEF2D is a super-enhancer-associated, highly expressed gene in MLL-r AML. Knockout of MEF2D profoundly impaired leukemia growth, induced myeloid differentiation, and delayed oncogenic progression in vivo. Mechanistically, MEF2D loss led to robust activation of a CEBPE-centered myeloid differentiation program in AML cells. Chromatin profiling revealed that MEF2D binds to and suppresses the chromatin accessibility of CEBPE cis-regulatory regions. In human acute leukemia samples, MEF2D expression showed a strong negative correlation with the expression of CEBPE. Depletion of CEBPE partially rescued the cell growth defect and myeloid cell differentiation induced by the loss of MEF2D. Lastly, we show that MEF2D is positively regulated by HOXA9, and downregulation of MEF2D is an important mechanism for DOT1L inhibitor-induced antileukemia effects. Collectively, our findings suggest that MEF2D plays a critical role in human MLL-r AML and uncover the MEF2D-CEBPE axis as a crucial transcriptional mechanism regulating leukemia cell self-renewal and differentiation block.
| S-EPMC8759131 | biostudies-literature
Project description:Interferon regulatory factor 8 (IRF8) is a transcription factor that plays a critical role in normal hematopoiesis, such that disruption of IRF8 activity promotes leukemogenesis. We and others have identified aberrant expression of IRF8 transcripts, including novel splice variants, in acute myeloid leukemia (AML), but studies have not investigated the prognostic significance of these transcripts. Therefore, we developed and optimized quantitative expression assays for both, the wild type, or the reference sequence (WT-IRF8) and novel splice variants (SV-IRF8). These assays were used to quantify IRF8 transcript levels in 194 adult patients with AML, and multivariate analyses investigated the prognostic significance of these expression levels. After adjusting for known prognostic factors, expression levels of WT- or SV-IRF8 transcripts were not significantly associated with complete responses or overall survival. However, increased expression of WT-IRF8 was associated with decreased relapse-free survival (RFS) in both univariate (P?=?0.010) and multivariate (P?=?0.019) analyses. Similarly, increased expression of SV-IRF8 was associated with a decreased RFS (univariate, P?=?0.026 and multivariate, P?=?0.021). These studies show for the first time that WT-IRF8 and SV-IRF8 are independent adverse prognostic factors for patients with AML. Additional studies are planned to examine the prognostic significance of IRF8 transcripts in other populations of AML patients.
| S-EPMC3743845 | biostudies-literature