Project description:Acute myeloid leukemia is a heterogeneous disease which is subdivided into different categories defined by disease-causing mutations in transcription factors, epigenetic regulators and signalling molecules. How different mutant regulators establish AML-specific transcriptional networks is unclear. Here we performed a comprehensive analysis of mutation-specific sets of cis-regulatory elements driving gene expression in AML blast cells from a carefully selected group of patients with alterations in genes encoding transcription factors (RUNX1, CEBPA) and signalling molecules (FTL3-ITD, RAS, NPM1). We show that each mutant regulator establishes a specific transcriptional and signalling network unrelated to normal cells driving the expression of unique sets of genes required for AML survival.
Project description:Acute myeloid leukemia (AML) is a heterogeneous disease caused by a variety of alterations in transcription factors, epigenetic regulators and signaling molecules. To determine how different mutant regulators establish AML subtype-specific transcriptional networks, we performed a comprehensive global analysis of cis-regulatory element activity and interaction, transcription factor occupancy and gene expression patterns in purified leukemic blast cells. Here, we focused on specific subgroups of subjects carrying mutations in genes encoding transcription factors (RUNX1, CEBP?), signaling molecules (FTL3-ITD, RAS) and the nuclear protein NPM1). Integrated analysis of these data demonstrates that each mutant regulator establishes a specific transcriptional and signaling network unrelated to that seen in normal cells, sustaining the expression of unique sets of genes required for AML growth and maintenance.
Project description:Acute myeloid leukemia is a heterogeneous disease which is subdivided into different categories defined by disease-causing mutations in transcription factors, epigenetic regulators and signalling molecules. How different mutant regulators establish AML-specific transcriptional networks is unclear. Here we performed a comprehensive analysis of mutation-specific sets of cis-regulatory elements driving gene expression in AML blast cells from a carefully selected group of patients with alterations in genes encoding transcription factors (RUNX1, CEBPA) and signalling molecules (FTL3-ITD, RAS, NPM1). We show that each mutant regulator establishes a specific transcriptional and signalling network unrelated to normal cells driving the expression of unique sets of genes required for AML survival.
Project description:Acute myeloid leukemia is a heterogeneous disease which is subdivided into different categories defined by disease-causing mutations in transcription factors, epigenetic regulators and signalling molecules. How different mutant regulators establish AML-specific transcriptional networks is unclear. Here we performed a comprehensive analysis of mutation-specific sets of cis-regulatory elements driving gene expression in AML blast cells from a carefully selected group of patients with alterations in genes encoding transcription factors (RUNX1, CEBPA) and signalling molecules (FTL3-ITD, RAS, NPM1). We show that each mutant regulator establishes a specific transcriptional and signalling network unrelated to normal cells driving the expression of unique sets of genes required for AML survival.
Project description:Acute myeloid leukemia (AML) is a set of heterogeneous myeloid malignancies hallmarked by mutations in epigenetic modifiers, transcription factors and kinases that can cause epigenetic reshaping. It is unclear whether those mutations drive chromatin 3D structure alteration and contribute to oncogenic dysregulation in AML. By performing Hi-C and whole genome sequencing in 21 primary AML and healthy donors’ samples, we identified recurrent AML- or subtype-specific alteration of compartments, TADs, and chromatin loops. To study the impact on gene regulation, we performed RNA-Seq, ATAC-Seq and CUT&TAG for CTCF, H3K27ac, and H3K27me3 in the same samples. We observed dysregulation of many AML-related genes, represented by MYCN, MEIS1, WT1, ERG, MYC GATA3, BCL11B and IKZF2, intimately linked to the recurrent gain of loops and switch of compartment or TAD, alongside acquisition of AML-specific enhancer or repressor. Further, we profiled structure variations using WGS and Hi-C data to reconstruct the cancer 3D genome, by which we identified structure variation-induced neo-loops and enhancer-hijacking events. Furthermore, through conducting whole genome bisulfite sequencing in patient samples, we found altered methylation correlated with A/B compartment switch, and loss of CTCF insulation due to hypermethylation, leading to extensive gain of loops in AML. By treating the AML cells with DNA hypomethylation agent 5-azacytidine, the altered chromatin structure and gene expression can be restored, with switched compartment reverted and gained loops dissociated, alongside compromised AML cell proliferation, overall providing insights into AML treatment through therapeutic restoration of chromatin structure.
Project description:Acute myeloid leukemia (AML) is a highly heterogeneous cancer associated with different patterns of gene expression determined by the nature of their DNA mutations. These mutations mostly act to deregulate gene expression by various mechanisms at the level of the nucleus. By performing genome-wide epigenetic profiling of cis-regulatory elements, we found that AML encompasses different mutation-specific subclasses associated with the rewiring of the gene regulatory networks that drive differentiation into different directions away from normal myeloid development. By integrating epigenetic profiles with gene expression and chromatin conformation data, we defined pathways within gene regulation networks that were differentially rewired within each mutation-specific subclass of AML. This analysis revealed 2 major classes of AML: one class defined by mutations in signaling molecules that activate AP-1 via the mitogen-activated protein (MAP) kinase pathway and a second class defined by mutations within genes encoding transcription factors such as RUNX1/CBFβ and C/EBPα. By identifying specific DNA motifs protected from DNase I digestion at cis-regulatory elements, we were able to infer candidate transcription factors bound to these motifs. These integrated analyses allowed the identification of AML subtype-specific core regulatory networks that are required for AML development and maintenance, which could now be targeted in personalized therapies.