Proteasome Inhibition Targets the KMT2A Transcriptional Complex
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE152816 | GEO | 2022/01/13
REPOSITORIES: GEO
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Project description:Chromosomal translocations involving the Lysine-Methyl-Tansferase-2A (KMT2A) locus generate potent oncogenes that cause highly aggressive acute leukemias KMT2A and the most frequent translocation partners encode proteins that interact with DNA to regulate developmental gene expression. KMT2A-oncogenic fusion proteins (oncoproteins) contribute to the epigenetic mechanisms that allow KMT2A-rearranged leukemias to evade targeted therapies. By profiling the oncoprotein-target sites of 34 KMT2A-rearranged leukemia samples, we find that the genomic enrichment of oncoprotein binding is highly variable between samples. At high levels of expression, the oncoproteins preferentially activate either the lymphoid or myeloid lineage program depending on the fusion partner. These fusion-partner-dependent binding sites correspond to the frequencies of each mutation in acute lymphoid leukemia versus acute myeloid leukemia. By profiling a sample that underwent a lymphoid-to-myeloid lineage switching event in response to lymphoid-directed treatment, we find the global oncoprotein levels are reduced and the oncoprotein-target gene network changes. At lower levels of expression, the oncoprotein shifts to a non-canonical regulatory program that favors the myeloid lineage, and in a subset of resistant patients, the Menin inhibitor Revumenib induces a similar response. The dynamic shifts in KMT2A oncoproteins we describe likely contribute to epigenetic resistance of KMT2A-rearranged leukemias to targeted therapies.
2024-09-27 | GSE252378 | GEO
Project description:Activating mutations in kinase/PI3K/RAS signaling pathways are common in acute leukemia with KMT2A rearrangements (KMT2A-R). These mutations are often subclonal and their biological impact remain unclear. Using a retroviral acute myeloid leukemia model, we demonstrate that NRASG12D, FLT3ITD, and FLT3N676K accelerates KMT2A-MLLT3 leukemia onset. Importantly, also the presence of subclonal FLT3N676K in KMT2A-R leukemic cells shorten disease latency, possibly by providing stimulatory factors such as Mif. Acquired de novo mutations in Braf, Cbl, Kras, and Ptpn11 were identified in KMT2A-MLLT3 driven leukemia and favored clonal expansion. KMT2A-MLLT3 leukemia with an activating mutation enforce Myc- and Myb transcriptional modules, whereas KMT2A-MLLT3 leukemias lacking activating mutations displayed upregulation of signal transduction pathways. Our results provide new insight into the biology of KMT2A-R leukemia and highlights the importance of activated signaling as a contributing driver in this disease.
2018-05-02 | PXD008213 | Pride
Project description:Pharmacologic targeting of epigenetic protein complexes has shown significant in vitro responses in acute myeloid leukemia (AML). Early clinical trials in KMT2A-rearranged leukemia indicate rather transient responses and development of resistance. In an effort to define functional dependencies of KMT2A-fusions in AML, we identify the catalytic immunoproteasome subunit PSMB8 as a KMT2A-complex-specific vulnerability. Genetic and pharmacologic inactivation of PSMB8 results in impaired proliferation of murine and human leukemic cells while normal hematopoietic cells remain unaffected. Disruption of immunoproteasome function results in cellular enrichment of transcription factor BASP1, and consecutive repression of KMT2A-target genes. Pharmacologic targeting of PSMB8 improves efficacy of Menin-inhibitors, eradicates leukemia in primary human xenografts and shows preserved activity against Menin-inhibitor resistance mutations. This identifies and validates a cell-intrinsic mechanism whereby selective disruption of proteostasis results in altered transcription factor abundance and repression of oncogene-specific transcriptional networks. Therapeutic targeting of PSMB8-dependent transcription in combination with Menin-inhibition could thus eradicate KMT2A-complex driven AML.
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Project description:KMT2A-rearranged acute lymphoblastic leukemia (ALL) is an aggressive type of leukemia which represents the most common form diagnosed in infancy. Oncogenic KMT2A-fusion proteins recruit histone methyltransferase DOT1L which leads to misplaced H3K79 methylation inducing an abnormal transcriptomic landscape that favors leukemia development. Hence, inhibition of DOT1L represents an attractive therapeutic strategy. Unfortunately, the first-in-class DOT1L inhibitor pinometostat resulted in the development of resistance. To understand this resistance we established acquired resistance to DOT1L inhibition in a pediatric KMT2A::AFF1+ B-ALL cell line model that stably became ~35-fold more resistant to pinometostat. Interestingly, while becoming almost completely independent of DOT1L-mediated H3K79 methylation, these cells remained fully dependent on the physical presence of DOT1L, HOXA9, as well as the KMT2A::AFF1 fusion protein. Further characterization of these cells using RNA-, ChIP-, and ATAC-sequencing analyses revealed that acquired resistance to DOT1L inhibition leads to a selective loss of KMT2A-fusion driven epigenetic regulation and expression of genes such as PROM1 (encoding the hematopoietic/leukemia stem cell marker CD133) and its enhancer TAPT1, as well as other putative KMT2A::AFF1 target genes such as RUNX2, PRSS12, ZC3H12, and GNAQ. In contrast, the levels of H3K79me2 and expression of other KMT2A::AFF1 target genes, including HOXA9, MEIS1, and CDK6 remained unaffected. Concomitantly, pinometostat-resistant KMT2A::AFF1+ B-ALL cells showed upregulation of genes associated with a myeloid immunophenotype, including CD33, LILRB4/CD85k, MPEG1, CCL5, and LIMK1. Taken together, we here present a valuable model to study the adaptive potential of KMT2A-rearranged ALL upon losing dependency on one of its main oncogenic properties.
2023-09-27 | GSE230799 | GEO
Project description:KMT2A-rearranged acute lymphoblastic leukemia (ALL) is an aggressive type of leukemia which represents the most common form diagnosed in infancy. Oncogenic KMT2A-fusion proteins recruit histone methyltransferase DOT1L which leads to misplaced H3K79 methylation inducing an abnormal transcriptomic landscape that favors leukemia development. Hence, inhibition of DOT1L represents an attractive therapeutic strategy. Unfortunately, the first-in-class DOT1L inhibitor pinometostat resulted in the development of resistance. To understand this resistance we established acquired resistance to DOT1L inhibition in a pediatric KMT2A::AFF1+ B-ALL cell line model that stably became ~35-fold more resistant to pinometostat. Interestingly, while becoming almost completely independent of DOT1L-mediated H3K79 methylation, these cells remained fully dependent on the physical presence of DOT1L, HOXA9, as well as the KMT2A::AFF1 fusion protein. Further characterization of these cells using RNA-, ChIP-, and ATAC-sequencing analyses revealed that acquired resistance to DOT1L inhibition leads to a selective loss of KMT2A-fusion driven epigenetic regulation and expression of genes such as PROM1 (encoding the hematopoietic/leukemia stem cell marker CD133) and its enhancer TAPT1, as well as other putative KMT2A::AFF1 target genes such as RUNX2, PRSS12, ZC3H12, and GNAQ. In contrast, the levels of H3K79me2 and expression of other KMT2A::AFF1 target genes, including HOXA9, MEIS1, and CDK6 remained unaffected. Concomitantly, pinometostat-resistant KMT2A::AFF1+ B-ALL cells showed upregulation of genes associated with a myeloid immunophenotype, including CD33, LILRB4/CD85k, MPEG1, CCL5, and LIMK1. Taken together, we here present a valuable model to study the adaptive potential of KMT2A-rearranged ALL upon losing dependency on one of its main oncogenic properties.
2023-09-27 | GSE230791 | GEO
Project description:KMT2A-rearranged acute lymphoblastic leukemia (ALL) is an aggressive type of leukemia which represents the most common form diagnosed in infancy. Oncogenic KMT2A-fusion proteins recruit histone methyltransferase DOT1L which leads to misplaced H3K79 methylation inducing an abnormal transcriptomic landscape that favors leukemia development. Hence, inhibition of DOT1L represents an attractive therapeutic strategy. Unfortunately, the first-in-class DOT1L inhibitor pinometostat resulted in the development of resistance. To understand this resistance we established acquired resistance to DOT1L inhibition in a pediatric KMT2A::AFF1+ B-ALL cell line model that stably became ~35-fold more resistant to pinometostat. Interestingly, while becoming almost completely independent of DOT1L-mediated H3K79 methylation, these cells remained fully dependent on the physical presence of DOT1L, HOXA9, as well as the KMT2A::AFF1 fusion protein. Further characterization of these cells using RNA-, ChIP-, and ATAC-sequencing analyses revealed that acquired resistance to DOT1L inhibition leads to a selective loss of KMT2A-fusion driven epigenetic regulation and expression of genes such as PROM1 (encoding the hematopoietic/leukemia stem cell marker CD133) and its enhancer TAPT1, as well as other putative KMT2A::AFF1 target genes such as RUNX2, PRSS12, ZC3H12, and GNAQ. In contrast, the levels of H3K79me2 and expression of other KMT2A::AFF1 target genes, including HOXA9, MEIS1, and CDK6 remained unaffected. Concomitantly, pinometostat-resistant KMT2A::AFF1+ B-ALL cells showed upregulation of genes associated with a myeloid immunophenotype, including CD33, LILRB4/CD85k, MPEG1, CCL5, and LIMK1. Taken together, we here present a valuable model to study the adaptive potential of KMT2A-rearranged ALL upon losing dependency on one of its main oncogenic properties.
2023-09-27 | GSE230806 | GEO
Project description:This study characterized the effect of WEE1 kinase inhibition using AZD1775 treatment on single-cell accessible chromatin and gene expression profile in the acute lymphoblastic leukemia cell line RS4;11 that represents the KMT2A-rearranged subtype.
2023-05-14 | GSE218805 | GEO
Project description:Activating signaling mutations are common in acute leukemia with KMT2A (previously MLL) rearrangements. Herein, we show that co-expression of FLT3-N676K and KMT2A-MLLT3 in human CD34+ cord blood cells primarily cause acute myeloid leukemia (AML) and rarely acute lymphoblastic leukemia (ALL) in immunodeficient mice. By contrast, expression of KMT2A-MLLT3 alone cause ALL, double-positive leukemia (DPL, expressing both CD33 and CD19), or bilineal leukemia (BLL, comprised of distinct myeloid and lymphoid leukemia cells), and rarely AML. Further, AML could only be serially propagated with maintained immunophenotype in secondary recipients when cells co-expressed KMT2A-MLLT3 and FLT3-N676K. Consistent with the idea that activated signaling would allow myeloid cells to engraft and maintain their self-renewal capacity, in a secondary recipient, a de novo KRAS-G13D was identified in myeloid cells previously expressing only KMT2A-MLLT3. Gene expression profiling revealed that KMT2A-MLLT3 DPL had a highly similar gene expression profile to ALL, with both expressing key lymphoid transcription factors and ALL cell surface markers, in line with the DPL cells being ALL cells with aberrant expression of CD33. Taken together, our results highlight the need for constitutive active signaling mutations for driving myeloid leukemia in a human xenograft model of KMT2A-R acute leukemia.
2019-04-05 | GSE127492 | GEO
Project description:Acute myeloid leukemia (AML) is a disease with poor outcome but patients harbouring certain chromosomal rearrangements or complex karyotypes have particularly adverse prognosis. For these patients, targeted therapies have not yet made a significant clinical impact. To understand the molecular landscape of poor risk AML we profiled 55 poor risk AML patients using a multiomics approach that included transcriptomics (n=39), proteomics (n=55), phosphoproteomics (n=55) and an ex vivo drug sensitivity screening (482 compounds tested in at least 30 patients). We identified a phosphoproteomics signature that define two biologically distinct groups of KMT2A rearranged leukaemia, which we term MLLGA and MLLGB. MLLGA presented increased DOT1L phosphorylation, HOXA gene expression, CDK1 activity and phosphorylation of proteins involved in RNA metabolism, replication and DNA damage when compared to MLLGB and no KMT2A rearranged samples. MLLGA was particularly sensitive to 15 compounds including genotoxic drugs and inhibitors of mitotic kinases and IMPDH relative to other cases. The expression of IMPDH2 and multiple nucleolar proteins was higher in MLLGA and correlated with the response to IMPDH inhibition in KMT2A rearranged leukaemia, suggesting a role of the nucleolar activity in sensitivity to IMPDH inhibition. In summary, our multilayer molecular profiling of poor risk AML matched to the response to hundreds of compounds identified a phosphoproteomics signature that define two biologically and phenotypically distinct groups of KMT2A rearranged leukaemia. These data provide a rationale for the development of specific therapies for KMT2A subgroups characterised by the MLLGA phosphoproteomics signature identified in this study.
2023-03-11 | PXD036669 | Pride
Project description:This study characterized the effect of WEE1 kinase inhibition using AZD1775 treatment on single-cell gene expression profile using the 10x Genomics protocol in the acute lymphoblastic leukemia cell lines RS4;11 (KMT2A-rearranged subtype) and Nalm6 (other subtype).
2023-05-14 | GSE218621 | GEO