Anti-tumor activity of trastuzumab deruxtecan in pediatric solid tumors with variable HER2 expression.

Trastuzumab deruxtecan (T-DXd) is a HER2-targeting antibody-drug conjugate (ADC) with efficacy across adult cancers exhibiting variable HER2 expression. Prior studies demonstrating HER2 expression in osteosarcoma (OS) motivated a clinical trial of T-DXd in pediatric and adolescent/young adults with OS but was terminated early for inactivity. We evaluated the activity of T-DXd using OS patient-derived xenograft (PDX) models and found a 22% objective response rate despite no detectable HER2 expression across PDXs tested.

PAX3-FOXO1 Drives Targetable Cell State-Dependent Metabolic Vulnerabilities in Rhabdomyosarcoma.

PAX3-FOXO1, an oncogenic transcription factor, drives a particularly aggressive subtype of rhabdomyosarcoma (RMS) by enforcing gene expression programs that support malignant cell states. Here, we showed that PAX3-FOXO1+ RMS cells exhibit altered pyrimidine metabolism and increased dependence on enzymes involved in de novo pyrimidine synthesis, including dihydrofolate reductase (DHFR). Consequently, PAX3-FOXO1+ cells displayed increased sensitivity to inhibition of DHFR by the chemotherapeutic drug methotrexate, and this dependence was rescued by provision of pyrimidine nucleotides.

PAX3-FOXO1 drives targetable cell state-dependent metabolic vulnerabilities in rhabdomyosarcoma.

PAX3-FOXO1, an oncogenic transcription factor, drives a particularly aggressive subtype of rhabdomyosarcoma (RMS) by enforcing gene expression programs that support malignant cell states. Here we show that PAX3-FOXO1 RMS cells exhibit altered pyrimidine metabolism and increased dependence on enzymes involved in pyrimidine synthesis, including dihydrofolate reductase (DHFR). Consequently, PAX3-FOXO1 cells display increased sensitivity to inhibition of DHFR by the chemotherapeutic drug methotrexate, and this dependence is rescued by provision of pyrimidine nucleotides.

A Transcriptome-Based Precision Oncology Platform for Patient-Therapy Alignment in a Diverse Set of Treatment-Resistant Malignancies.

Unlabelled: Predicting in vivo response to antineoplastics remains an elusive challenge. We performed a first-of-kind evaluation of two transcriptome-based precision cancer medicine methodologies to predict tumor sensitivity to a comprehensive repertoire of clinically relevant oncology drugs, whose mechanism of action we experimentally assessed in cognate cell lines. We enrolled patients with histologically distinct, poor-prognosis malignancies who had progressed on multiple therapies, and developed low-passage, patient-derived xenograft models that were used to validate 35 patient-specific drug predictions.

Validation of a non-oncogene encoded vulnerability to exportin 1 inhibition in pediatric renal tumors.

Background: Malignant rhabdoid tumors (MRTs) and Wilms' tumors (WTs) are rare and aggressive renal tumors of infants and young children comprising ∼5% of all pediatric cancers. MRTs are among the most genomically stable cancers, and although WTs are genomically heterogeneous, both generally lack therapeutically targetable genetic mutations.

Methods: Comparative protein activity analysis of MRTs (n = 68) and WTs (n = 132) across TCGA and TARGET cohorts, using metaVIPER, revealed elevated exportin 1 (XPO1) inferred activity.

RRM2 enhances MYCN-driven neuroblastoma formation and acts as a synergistic target with CHK1 inhibition.

High-risk neuroblastoma, a pediatric tumor originating from the sympathetic nervous system, has a low mutation load but highly recurrent somatic DNA copy number variants. Previously, segmental gains and/or amplifications allowed identification of drivers for neuroblastoma development. Using this approach, combined with gene dosage impact on expression and survival, we identified ribonucleotide reductase subunit M2 (RRM2) as a candidate dependency factor further supported by growth inhibition upon in vitro knockdown and accelerated tumor formation in a neuroblastoma zebrafish model coexpressing human RRM2 with MYCN.

Bromodomain 4 inhibition leads to MYCN downregulation in Wilms tumor.

Background: Wilms tumor is the most common childhood kidney cancer. Two distinct histological subtypes of Wilms tumor have been described: tumors lacking anaplasia (the favorable subtype) and tumors displaying anaplastic features (the unfavorable subtype). Children with favorable disease generally have a very good prognosis, whereas those with anaplasia are oftentimes refractory to standard treatments and suffer poor outcomes, leading to an unmet clinical need.

Limonene-induced activation of A adenosine receptors reduces airway inflammation and reactivity in a mouse model of asthma.

Animal models of asthma have shown that limonene, a naturally occurring terpene in citrus fruits, can reduce inflammation and airway reactivity. However, the mechanism of these effects is unknown. We first performed computational and molecular docking analyses that showed limonene could bind to both A and A receptors.

Effect of omega-3 fatty acid supplementation on resolvin (RvE1)-mediated suppression of inflammation in a mouse model of asthma.

ResolvinE1 (RvE1), an endogenous lipid mediator derived from omega 3 fatty acids contributes to resolution of allergic inflammatory responses. We investigated effects of RvE1 (R) and omega 3 fatty acids (O) on airway reactivity and inflammation using allergic mice. Mice were divided into control (nonasthmatic; CON) and allergen sensitized-challenged (asthmatic; SEN) groups, and were sensitized i.