Project description:Pediatric cancers are increasingly linked to transformation events before birth, yet how ontogeny influences oncogenesis remains poorly understood. Using a humanized model of NUP98-NSD1-driven pediatric acute myeloid leukemia, particularly aggressive when accompanied by WT1 mutations, we investigated how the developmental stage of hematopoietic stem cells impacts leukemic transformation, disease progression and therapy response. Fetal-derived hematopoietic stem cells readily transform into leukemia, with WT1 mutations enhancing stemness and alter lineage hierarchy, while stem cells from later developmental stages progressively withstand transformation. Single-cell analyses revealed that fetal-origin versus postnatal leukemic stem cells exhibit greater quiescence and metabolic reliance on oxidative phosphorylation. Notably, therapeutic responses markedly differed between fetal- and postnatal-origin leukemias, even when driven by the same oncogenic mutations. In patients, onco-fetal transcriptional programs were associated with worse outcomes. We identified tailored combination therapies that specifically diminished aggressive fetal-origin leukemia, underscoring the need to consider ontogeny in treatment of pediatric cancers.
Project description:Pediatric cancers are increasingly linked to transformation events before birth, yet how ontogeny influences oncogenesis remains poorly understood. Using a humanized model of NUP98-NSD1-driven pediatric acute myeloid leukemia, particularly aggressive when accompanied by WT1 mutations, we investigated how the developmental stage of hematopoietic stem cells impacts leukemic transformation, disease progression and therapy response. Fetal-derived hematopoietic stem cells readily transform into leukemia, with WT1 mutations enhancing stemness and alter lineage hierarchy, while stem cells from later developmental stages progressively withstand transformation. Single-cell analyses revealed that fetal-origin versus postnatal leukemic stem cells exhibit greater quiescence and metabolic reliance on oxidative phosphorylation. Notably, therapeutic responses markedly differed between fetal- and postnatal-origin leukemias, even when driven by the same oncogenic mutations. In patients, onco-fetal transcriptional programs were associated with worse outcomes. We identified tailored combination therapies that specifically diminished aggressive fetal-origin leukemia, underscoring the need to consider ontogeny in treatment of pediatric cancers.
Project description:Pediatric cancers are increasingly linked to transformation events before birth, yet how ontogeny influences oncogenesis remains poorly understood. Using a humanized model of NUP98-NSD1-driven pediatric acute myeloid leukemia, particularly aggressive when accompanied by WT1 mutations, we investigated how the developmental stage of hematopoietic stem cells impacts leukemic transformation, disease progression and therapy response. Fetal-derived hematopoietic stem cells readily transform into leukemia, with WT1 mutations enhancing stemness and alter lineage hierarchy, while stem cells from later developmental stages progressively withstand transformation. Single-cell analyses revealed that fetal-origin versus postnatal leukemic stem cells exhibit greater quiescence and metabolic reliance on oxidative phosphorylation. Notably, therapeutic responses markedly differed between fetal- and postnatal-origin leukemias, even when driven by the same oncogenic mutations. In patients, onco-fetal transcriptional programs were associated with worse outcomes. We identified tailored combination therapies that specifically diminished aggressive fetal-origin leukemia, underscoring the need to consider ontogeny in treatment of pediatric cancers.
Project description:Pediatric cancers are increasingly linked to transformation events before birth, yet how ontogeny influences oncogenesis remains poorly understood. Using a humanized model of NUP98-NSD1-driven pediatric acute myeloid leukemia, particularly aggressive when accompanied by WT1 mutations, we investigated how the developmental stage of hematopoietic stem cells impacts leukemic transformation, disease progression and therapy response. Fetal-derived hematopoietic stem cells readily transform into leukemia, with WT1 mutations enhancing stemness and alter lineage hierarchy, while stem cells from later developmental stages progressively withstand transformation. Single-cell analyses revealed that fetal-origin versus postnatal leukemic stem cells exhibit greater quiescence and metabolic reliance on oxidative phosphorylation. Notably, therapeutic responses markedly differed between fetal- and postnatal-origin leukemias, even when driven by the same oncogenic mutations. In patients, onco-fetal transcriptional programs were associated with worse outcomes. We identified tailored combination therapies that specifically diminished aggressive fetal-origin leukemia, underscoring the need to consider ontogeny in treatment of pediatric cancers.
Project description:Drug dosing for children is frequently suboptimal when relying on the traditional approach of normalizing doses based on body weight or surface area. Thus, the ontogeny profiling of drug-metabolizing enzymes (DMEs) is important to help develop physiologically-based pharmacokinetic (PBPK) models for predicting safer pediatric dosing. In particular interest are hydrolases are one of the most diverse classes of DMEs and catalyze reactions containing esters, amides, phosphates, etc. in both drugs and prodrugs. Hydrolases such as carboxyl esterases, cathepsins, and arylacetamide deacetylase have been studied for their involvement in drug metabolism. However, a significant number of hydrolases have not yet been appropriately characterized, and as such their influence on drug metabolism remains unknown. Moreover, there is a lack of comprehensive data on the ontogeny and inter-individual variability in expression of these enzymes. Here a characterization of the age-dependent protein abundance of hydrolases in viable primary human hepatocytes isolated from pediatric (n=50) and adult (n=8) donors (Female=28; Male=30) using quantitative global proteomics-based total protein approach was performed.
Project description:The outcome for children with high-grade gliomas (HGG) remains dismal, with a two-year survival rate of only 10-30%. Approximately half of pediatric HGGs are diffuse intrinsic pontine glioma (DIPG), a brainstem tumor that arises almost exclusively in children. Genome-wide analyses of copy number imbalances previously showed that platelet derived growth factor receptor alpha (PDGFRA) is the most frequent target of focal amplification in pediatric HGGs. To determine whether the PDGFRA is also targeted by more subtle mutations not detected by copy number analysis, we sequenced all PDGFRA coding exons from a cohort of pediatric HGGs. Somatic activating mutations were identified in 14.4% (13/90) of non-brainstem pediatric HGGs and 4.7% (2/43) of DIPGs, including missense mutations and in-frame deletions and insertions not previously described. 40% of tumors with mutation showed concurrent amplification, while 60% carried heterozygous mutations. Six different mutations impacting different domains all resulted in ligand-independent receptor activation that was blocked by small molecule inhibitors of PDGFR. Expression of mutants in p53-null primary mouse astrocytes conferred a proliferative advantage in vitro, and generated HGGs in vivo with complete penetrance when implanted into brain. The gene expression signatures reflected the spectrum of human diffuse HGGs. PDGFRA intragenic deletion of exons 8 and 9 were previously shown in adult HGG, but were not detected in 83 non-brainstem pediatric HGG and 57 DIPGs. Thus, a distinct spectrum of mutations confers constitutive receptor activation and oncogenic activity to PDGFR in childhood HGG. To better understand the consequence of PDGFRα mutation in pediatric gliomagenesis, retroviral constructs expressing wild-type PDGFRα or six selected PDGFRα mutants that affect different regions of the receptor were generated for functional studies. p53-null primary mouse astrocyte (PMA) cultures were chosen as a relevant cellular background to assess PDGFRα function.