Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Targeting the Epichaperome As an Effective Precision Medicine Approach in a Novel PML-SYK Fusion Acute Myeloid Leukemia

ABSTRACT: The epichaperome is a new cancer target composed of hyperconnected networks of chaperome members that facilitate cell survival. Cancers with an altered chaperone configuration may be susceptible to epichaperome inhibitors. We developed a flow cytometry-based assay for evaluation and monitoring of epichaperome abundance at the single cell level, with the goal of prospectively identifying patients likely to respond to epichaperome inhibitors, to measure target engagement, and dependency during treatment. As proof of principle, we describe a patient with an unclassified myeloproliferative neoplasm harboring a novel PML-SYK fusion, who progressed to acute myeloid leukemia despite chemotherapy and allogeneic stem cell transplant. The leukemia was identified as having high epichaperome abundance. We obtained compassionate access to an investigational epichaperome inhibitor, PU-H71. After 16 doses, the patient achieved durable complete remission. These encouraging results suggest that further investigation of epichaperome inhibitors in patients with abundant baseline epichaperome levels is warranted.

PROVIDER: EGAS00001004992 | EGA |

REPOSITORIES: EGA

ACCESS DATA

Json Xml

Similar Datasets

Mezigdomide is effective alone and in combination with Menin inhibition in Acute Myeloid Leukemia

Project description:Small molecules that target the MENIN-KMT2A protein-protein interaction (Menin inhibitors) have recently entered clinical trials in lysine methyltransferase 2A (KMT2A, MLL1) rearranged (KMT2A-r) and nucleophosmin mutant (NPM1c) acute myeloid leukemia (AML) and are demonstrating encouraging results. However, rationally chosen combination therapy is needed to improve responses and prevent resistance. We have previously identified IKZF1/IKAROS as a target in KMT2A-r AML and shown in preclinical models that IKAROS protein degradation with Lenalidomide or Iberdomide has modest single-agent activity yet can synergize with Menin inhibitors. Recently, the novel IKAROS degrader Mezigdomide was developed and has greatly enhanced IKAROS protein degradation. In this study we show that Mezigdomide has increased preclinical activity in vitro as a single-agent in KMT2A-r and NPM1c AML cell lines, including sensitivity in cell lines resistant to Lenalidomide and Iberdomide. Further, we demonstrate that Mezigdomide has the greatest capacity to synergize with and induce apoptosis in combination with Menin inhibitors. We show that the superior activity of Mezigdomide compared to Lenalidomide or Iberdomide is due to its increased depth, rate, and duration of IKAROS protein degradation. Single-agent Mezigdomide was efficacious in five patient derived xenograft (PDX) models of KMT2A-r and one NPM1c AML. The combination of Mezigdomide with a Menin inhibitor increased survival and prevented the development of recently described MEN1 mutations. These results support prioritization of Mezigdomide for early phase clinical trials in KMT2A-r and NPM1c AML, either as a single-agent or in combination with Menin inhibitors.

2024-02-15 | PXD041737 | Pride

Mezigdomide is effective alone and in combination with Menin inhibition in Acute Myeloid Leukemia

2024-02-15 | PXD041735 | Pride

Chromatin Topology Reorganization and Transcription Repression by PML/RARα in Acute Promyeloid Leukemia (ChIA-PET)

Project description:Acute promyeloid leukemia (APL) is characterized by the oncogenic fusion protein PML/RARα, a major etiological agent in APL. Although PML/RARα is critical, the molecular mechanisms remains largely unknown. Here, using an inducible system, we comprehensively analyzed the 3D genome organization in myloid cells and its reorganizationn after PML/RARα induction, and performed additional analysis in patient-derived APL cells with native PML/RARα. We discovered that PML/RARα mediate extensive chromatin interactions genome-wide. Globally, it redefine the chromatin topology of the in myloid genome toward a more condensed configuration in APL cells; locally, it intrude RNAPII-associated interaction dmains, interrupt myeloid-specific transcription factors binding at enhancers and super-enahncers, and lead to transcriptional repression of genes critical for myeloid differentiation and maturation. Together, our results provide novel insights of a topological framework for PML/RARα’s roles in transforming myeloid into leukemia, likely a general mechanism for oncogenic fusion proteins in cancers.

2019-12-05 | GSE137661 | GEO

Chromatin Topology Reorganization and Transcription Repression by PML/RARα in Acute Promyeloid Leukemia (RNA-seq)

2019-12-17 | GSE142198 | GEO

Chromatin Topology Reorganization and Transcription Repression by PML/RARα in Acute Promyeloid Leukemia (ChIP-seq)

2019-12-17 | GSE142197 | GEO

Genome-wide studies identify the role of PML/RARα phase separation in PML/RARα and BRD4 chromatin occupancy

Project description:Acute promyelocytic leukemia (APL) is characterized by a specific t(15;17) chromosome translocation that generates the promyelocytic leukemia/retinoic acid receptor-α (PML/RARα) fusion gene. However, the global association between PML/RARα and transcriptional co-regulators, and the rules of their association in governing the key processes during the leukemogenesis remain unclear. Here, we performed the genome-wide binding profiling of PML/RARα and BRD4 in NB4, an APL patient-derived cell line. Moreover, we also performed ChIP-seq of PML/RARα and BRD4 upon genetic or pharmacological pertubation of PML/RARα or BRD4 to determine how they target regulatory elements.

2024-12-31 | GSE261292 | GEO

PML is a ROS sensor activating p53 upon oxidative stress

Project description:PML nuclear bodies (NBs) recruit partner proteins -including p53 and its regulators- controlling their abundance or function. Investigating arsenic sensitivity of acute promyelocytic leukemia, we proposed that PML oxidation promotes NB-biogenesis. Yet, physiological links between PML and oxidative stress response in vivo remain unexplored. Here we identify PML as a reactive oxygen species (ROS) sensor. Pml-/- cells accumulate ROS, while PML expression decreases ROS levels. Unexpectedly, Pml-/- embryos survive acute glutathione depletion. Moreover, Pml-/- animals are resistant to acetaminophen hepatotoxicity or fasting-induced steatosis. Molecularly, Pml-/- animals fail to properly activate oxidative stress-responsive p53 targets, while NRF2 response is accelerated. Finally, in an oxidative stress-prone background, Pml-/- animals display a longevity phenotype, likely reflecting decreased basal p53 activation. Thus, similar to p53, PML exerts basal anti-oxidant properties, but also drives oxidative stress-induced changes in cell survival/proliferation or metabolism in vivo. Through NB-biogenesis, PML therefore couples ROS-sensing to p53 responses, shedding a new light on PML role in senescence or stem cell biology.

2017-09-22 | GSE103642 | GEO

Paediatric Glioma Histone H3.3 K27M/G34R Mutations Drive Abnormalities in Phase-Separated PML Nuclear Bodies.

Project description:Point mutations in histone variant H3.3 (H3.3 K27M, H3.3 G34R) and the H3.3-specific ATRX/DAXX chaperone complex are frequent events in paediatric gliomas. It is clear that H3.3 point mutations affect many chromatin modifications but the exact oncogenic mechanisms are an area of active investigation. Histone H3.3 has been previously linked to PML, a gene which is frequently mutated in Acute Promyelocytic Leukaemia. We find that H3.3 point mutations disrupt the formation of PML nuclear bodies and this prevents differentiation down glial lineages. Similar to PML-mutated Acute Promyelocytic Leukaemias, H3.3-mutated patient-derived gliomas cells are also sensitive to drugs which target PML bodies. We identify PML as a contributor to oncogenesis in H3.3-mutated gliomas and our results indicate that PML-targeting strategies may prove effective at treating H3.3-mutated paediatric gliomas.

2023-11-19 | GSE210190 | GEO

Interplay between PML NBs and HIRA for H3.3 deposition on transcriptionally active interferon-stimulated genes

Project description:Promyelocytic Leukemia Nuclear Bodies (PML NBs) are nuclear membrane-less organelles physically associated with chromatin underscoring their crucial role in genome function. The H3.3 histone chaperone complex HIRA accumulates in PML NBs upon senescence, viral infection or IFN-I treatment in primary cells. Yet, the molecular mechanisms of this partitioning and its function in regulating histone dynamics have remained elusive. Here, by using specific siRNAs and protein Affimers, we identify intermolecular SUMO-SIM interactions as an essential mechanism for HIRA recruitment in PML NBs. In addition, we demonstrate that HIRA localization in the nuclear bodies is intimately linked to the presence of a soluble pool of H3.3-H4 dimers inside PML NBs, that is not found in cancer cells. Transcription inhibition prevents HIRA accumulation in PML NBs underscoring the importance of transcriptional activity to drive HIRA through PML NBs. Finally, in the context of inflammatory responses, HIRA and PML are necessary for the prolonged H3.3 deposition at the transcriptional end sites of interferon-stimulated genes (ISGs), well beyond the peak of transcription. We thus propose that HIRA partitioning in PML NBs is essential to regulate H3.3 deposition on transcriptionally active regions.

2023-05-25 | GSE233298 | GEO

Interplay between PML NBs and HIRA for H3.3 deposition on transcriptionally active interferon-stimulated genes

2023-05-30 | GSE186937 | GEO