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Biology subjects

Ries, R. E.

Publications and source records attributed to Ries, R. E..

7 recordsLinked to original sources

TP53 Inactivation Confers Resistance to the Menin Inhibitor Revumenib in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a heterogeneous cancer that is associated with poor outcomes. Revumenib and other menin inhibitors have shown promising activity against AMLs with KMT2A-rearrangements or NPM1 mutations. However, mechanisms of de novo resistance have not yet been elucidated. We analyzed a panel of cell lines and generated an isogenic model to assess the impact of TP53 mutations on the response of AML cells to revumenib. TP53 mutations are associated with de novo resistance to revumenib, impaired induction of TP53 transcriptional targets, and deregulated expression of the BH3 proteins BCL-2 and MCL-1. The MCL-1 inhibitor MIK665, but not venetoclax, preferentially sensitized TP53-mutant AML cells to revumenib. These data identify mutant TP53 as a potential biomarker for de novo resistance to revumenib, and provide a rationale to evaluate MCL-1 and menin inhibitor combinations in patients KMT2A-rearranged leukemias with TP53 mutations.

cancer biology↗

Ontogeny Dictates Oncogenic Potential, Lineage Hierarchy, and Therapy Response in Pediatric Leukemia

Accumulating evidence links pediatric cancers to prenatal transformation events, yet the influence of the developmental stage on oncogenesis remains elusive. We investigated how hematopoietic stem cell developmental stages affect leukemic transformation, disease progression, and therapy response using a novel, humanized model of NUP98::NSD1-driven pediatric acute myeloid leukemia, that is particularly aggressive with WT1 co-mutations. Fetal-derived hematopoietic stem cells readily transform into leukemia, and WT1 mutations further enhance stemness and alter lineage hierarchy. In contrast, stem cells from later developmental stages become progressively resistant to transformation. Single-cell analyses revealed that fetal-origin leukemia stem cells exhibit greater quiescence and reliance on oxidative phosphorylation than their postnatal counterparts. These differences drive distinct therapeutic responses, despite identical oncogenic mutations. In patients, onco-fetal transcriptional programs correlate with worse outcomes. By targeting key vulnerabilities of fetal-origin leukemia cells, we identified combination therapies that significantly reduce aggressiveness, highlighting the critical role of ontogeny in pediatric cancer treatment.

cancer biology↗

Targeting DLK1 improves survival in patient-derived xenograft models of myeloid leukemia associated with Down syndrome

Children with Down syndrome have a markedly increased risk of developing myeloid leukemia (ML-DS). Although having an excellent prognosis, 10-20% develop relapsed or refractory disease with poor survival, highlighting the need for new targeted approaches. The pathogenesis of ML-DS is tightly linked to fetal hematopoiesis and mutations in GATA1, generating the truncated GATA1short(s) isoform. We identified Delta-like non-canonical Notch ligand 1 (DLK1) as a direct GATA1s target. DLK1, a paternally imprinted transmembrane protein, is highly expressed in fetal liver CD34 cells but absent in adult hematopoiesis, making it an attractive immunotherapeutic target. Chromatin profiling revealed GATA1s occupancy at a distal enhancer within the DLK1-DIO3 locus, driving aberrant DLK1 upregulation in ML-DS. Functional studies demonstrated that DLK1 is a leukemia dependency, as its genetic ablation impaired proliferation and engraftment, induced apoptosis, and altered Notch and {beta}-catenin signaling. Therapeutically, a DLK1-directed antibody-drug conjugate (DLK1-ADC) induced selective cytotoxicity, abrogated colony formation, and significantly prolonged survival in refractory ML-DS PDX models, achieving durable remissions at higher doses. These findings establish DLK1 as a leukemia-specific vulnerability and provide preclinical proof-of-concept for DLK1-targeted therapies in ML-DS and other leukemias with fetal-like expression programs. Key PointsO_LIDLK1 is a GATA1s-driven leukemia dependency in ML-DS, linking fetal hematopoietic programs to leukemic stemness and refractory disease. C_LIO_LITherapeutic targeting of DLK1 with an antibody-drug conjugate selectively eradicates leukemia cells and prolongs survival in ML-DS PDX models C_LI

cancer biology↗

EZH2-driven immune evasion defines high-risk pediatric AML with t(16;21) FUS::ERG gene fusion.

The past 25 years of clinical trials have produced few improvements in pediatric AML (pAML) outcomes. This is acutely evident in patients with t(16;21)(p11;q22), yielding FUS::ERG. Patients with FUS::ERG-positive AML relapse quickly and do not respond to transplantation. Major histocompatibility complex (MHC) class I & II receptors and costimulatory molecules are absent at diagnosis in FUS::ERG-positive AML, mirroring the phenotype and outcomes of post-transplant relapse. We show that this is driven by overexpression of EZH2, in vitro and in multiple clinical cohorts. While FUS::ERG AML is the most extreme example, this phenotype is shared by lethal CBFA2T3::GLIS2-driven AML, and patients with RUNX1::RUNX1T1 have significantly worse outcomes when EZH2 overexpression co-occurs. The FDA-approved EZH2 inhibitor tazemetostat reverses this phenotype, re-establishes MHC presentation, and elicits immune effector cell-mediated elimination. EZH2 inhibitors may provide the first targeted therapeutic frontline option for AML patients with FUS::ERG, with the potential for broader frontline immunostimulatory benefits. STATEMENT OF SIGNIFICANCEHere we show an immune-evasive phenotype, present at diagnosis and characterized by elevated EZH2 levels and loss of MHC class I and II, defines a high-risk subtype of acute leukemia. Treatment with the EZH2 inhibitor tazemetostat and IFN-{gamma} reverses this phenotype and results in immune cell engagement and blast elimination.

cancer biology↗

Myeloid Lineage Enhancers Drive Oncogene Synergy in CEBPA/CSF3R Mutant Acute Myeloid Leukemia

Acute Myeloid Leukemia (AML) develops due to the acquisition of mutations from multiple functional classes. Here, we demonstrate that activating mutations in the granulocyte colony stimulating factor receptor (CSF3R), cooperate with loss of function mutations in the transcription factor CEBPA to promote acute leukemia development. This finding of mutation-synergy is broadly applicable other mutations that activate the JAK/STAT pathway or disrupt CEBPA function (i.e. activating mutations in JAK3 and Core Binding Factor translocations). The interaction between these distinct classes of mutations occurs at the level of myeloid lineage enhancers where mutant CEBPA prevents activation of subset of differentiation associated enhancers. To confirm this enhancer-dependent mechanism, we demonstrate that CEBPA mutations must occur as the initial event in AML initiation, confirming predictions from clinical sequencing data. This improved mechanistic understanding will facilitate therapeutic development targeting the intersection of oncogene cooperativity.

cancer biology↗

RNAIndel: a machine-learning framework for discovery of somatic coding indels using tumor RNA-Seq data

Reliable identification of expressed somatic insertion/deletion (indels) is an unmet demand due to artifacts generated in PCR-based RNA-Seq library preparation and the lack of normal RNA-Seq data, presenting analytical challenges for discovery of somatic indels in tumor trasncriptome.\n\nBy implementing features characterized by PCR-free whole-genome and whole-exome sequencing into a machine-learning framework, we present RNAIndel, a tool for predicting somatic, germline and artifact indels from tumor RNA-Seq data alone. RNAIndel robustly predicts 87{square}93% of somatic indels from 235 samples with heterogeneous conditions, even recovering subclonal (VAF range 0.01-0.15) driver indels missed by targeted deep-sequencing, outperforming the current best-practice for RNA-Seq variant calling which had 57% sensitivity but with 12 times more false positives.\n\nRNAIndel is freely available at https://github.com/stjude/RNAIndel\n\nContactjinghui.zhang@stjude.org

bioinformatics↗

Comprehensive characterization of pediatric acute myeloid leukemia reveals novel molecular features and age-specific interactions

We present the molecular landscape of pediatric acute myeloid leukemia (AML), characterizing nearly 1,000 participants in Childrens Oncology Group (COG) AML trials. The COG/NCI TARGET AML initiative assessed cases by whole-genome, targeted DNA, mRNA, miRNA sequencing and CpG methylation profiling. Validated DNA variants revealed diverse, infrequent mutations with fewer than 40 genes mutated in >2% of cases. In contrast, somatic structural variants, including novel gene fusions and focal MBNL1, ZEB2, and ELF1 deletions, were disproportionately prevalent in young as compared to adult patients. Conversely, DNMT3A and TP53 mutations, common in adults, are conspicuously absent from virtually all pediatric cases. Novel GATA2, FLT3, and CBL mutations, recurrent MYC-ITD, NRAS, KRAS, and WT1 mutations are frequent in pediatric AML. Deletions, mutations, and promoter DNA hypermethylation convergently impact Wnt signaling, Polycomb repression, innate immune cell interactions, and a cluster of zinc finger genes associated with KMT2A rearrangements. These results highlight the need for, and facilitate the development of age-tailored targeted therapies for the treatment of pediatric AML.

cancer biology↗