Combined inhibition of ribonucleotide reductase and WEE1 induces synergistic anticancer activity in Ewing's sarcoma cells.

Background: Ewing's sarcoma is a childhood bone and soft tissue cancer with poor prognosis. Treatment outcomes for Ewing's sarcoma patients have improved only modestly over the past decades, making the development of new treatment strategies paramount. In this study, the combined targeting of ribonucleotide reductase (RNR) and WEE1 was explored for its effectiveness against Ewing's sarcoma cells.

Pediatric spinal high-grade glioma in the pediatric precision oncology registry INFORM: Identification of potential therapeutic targets.

Background: High-grade glioma (HGG) of the spinal cord constitutes rare tumors in the pediatric population. Knowledge of the molecular profile of this pediatric HGG (pedHGG) subgroup is limited and the clinical outcome is poor. Therefore, the aim of this study is to provide more profound investigations of molecular characteristics and clinical features of these tumors.

Biglycan-driven risk stratification in ZFTA-RELA fusion supratentorial ependymomas through transcriptome profiling.

Recent genomic studies have allowed the subdivision of intracranial ependymomas into molecularly distinct groups with highly specific clinical features and outcomes. The majority of supratentorial ependymomas (ST-EPN) harbor ZFTA-RELA fusions which were designated, in general, as an intermediate risk tumor variant. However, molecular prognosticators within ST-EPN ZFTA-RELA have not been determined yet.

Decoding pediatric spinal tumors: a single-center retrospective case series on etiology, presentation, therapeutic strategies, and outcomes.

Introduction: Spinal tumors (ST) often result in dire prognosis, carrying risks such as permanent paralysis, sensory loss, and sphincter dysfunction. Data on their incidence and etiology in pediatric populations are markedly scant. Our study investigates the etiology, clinical manifestation, treatment, and outcomes of pediatric ST.

Synergy of retinoic acid and BH3 mimetics in MYC(N)-driven embryonal nervous system tumours.

Background: Certain paediatric nervous system malignancies have dismal prognoses. Retinoic acid (RA) is used in neuroblastoma treatment, and preclinical data indicate potential benefit in selected paediatric brain tumour entities. However, limited single-agent efficacy necessitates combination treatment approaches.

Radiotherapy for Recurrent Medulloblastoma in Children and Adolescents: Survival after Re-Irradiation and First-Time Irradiation.

Background: Radiotherapy (RT) involving craniospinal irradiation (CSI) is important in the initial treatment of medulloblastoma. At recurrence, the re-irradiation options are limited and associated with severe side-effects.

Methods: For pre-irradiated patients, patients with re-irradiation (RT2) were matched by sex, histology, time to recurrence, disease status and treatment at recurrence to patients without RT2.

Clinically unfavorable transcriptome subtypes of non-WNT/non-SHH medulloblastomas are associated with a predominance in proliferating and progenitor-like cell subpopulations.

The non-WNT/non-SHH (Grp3/Grp4) medulloblastomas (MBs) include eight second-generation subgroups (SGS; I-VIII) each with distinct molecular and clinical characteristics. Recently, we also identified two prognostically relevant transcriptome subtypes within each SGS MB, which are associated with unique gene expression signatures and signaling pathways. These prognostic subsets may be in connection to the intra-tumoral cell landscape that underlies SGS MB clinical-molecular diversity.

MOST wanted: navigating the MAPK-OIS-SASP-tumor microenvironment axis in primary pediatric low-grade glioma and preclinical models.

Understanding the molecular and cellular mechanisms driving pediatric low-grade glioma (pLGG)-the most prevalent brain tumor in children-is essential for the identification and evaluation of novel effective treatments. This review explores the intricate relationship between the mitogen-activated protein kinase (MAPK) pathway, oncogene-induced senescence (OIS), the senescence-associated secretory phenotype (SASP), and the tumor microenvironment (TME), integrating these elements into a unified framework termed the MAPK/OIS/SASP/TME (MOST) axis. This integrated approach seeks to deepen our understanding of pLGG and improve therapeutic interventions by examining the MOST axis' critical influence on tumor biology and response to treatment.

Resistance, rebound, and recurrence regrowth patterns in pediatric low-grade glioma treated by MAPK inhibition: A modified Delphi approach to build international consensus-based definitions-International Pediatric Low-Grade Glioma Coalition.

Pediatric low-grade glioma (pLGG) is the most common childhood brain tumor group. The natural history, when curative resection is not possible, is one of a chronic disease with periods of tumor stability and episodes of tumor progression. While there is a high overall survival rate, many patients experience significant and potentially lifelong morbidities.

Germline biallelic BRCA2 pathogenic variants and medulloblastoma: an international cohort study.

Constitutional heterozygous pathogenic variants in genes coding for some components of the Fanconi anemia-BRCA signaling pathway, which repairs DNA interstrand crosslinks, represent risk factors for common cancers, including breast, ovarian, pancreatic and prostate cancer. A high cancer risk is also a main clinical feature in patients with Fanconi anemia (FA), a rare condition characterized by bone marrow failure, endocrine and physical abnormalities. The mainly recessive condition is caused by germline pathogenic variants in one of 21 FA-BRCA pathway genes.

Rebound growth of BRAF mutant pediatric glioma cells after MAPKi withdrawal is associated with MAPK reactivation and secretion of microglia-recruiting cytokines.

Introduction: Patients with pediatric low-grade gliomas (pLGGs), the most common primary brain tumors in children, can often benefit from MAPK inhibitor (MAPKi) treatment. However, rapid tumor regrowth, also referred to as rebound growth, may occur once treatment is stopped, constituting a significant clinical challenge.

Methods: Four patient-derived pediatric glioma models were investigated to model rebound growth in vitro based on viable cell counts in response to MAPKi treatment and withdrawal.

Combination drug screen identifies synergistic drug interaction of BCL-XL and class I histone deacetylase inhibitors in MYC-amplified medulloblastoma cells.

Purpose: Patients with MYC-amplified Group 3 medulloblastoma (MB) (subtype II) show poor progression-free survival rates. Class I histone deacetylase inhibitors (HDACi) are highly effective for the treatment of MYC-amplified MB in vitro and in vivo. Drug combination regimens including class I HDACi may represent an urgently needed novel treatment approach for this high risk disease.

Long-term use of everolimus for refractory arrhythmia in a child with tuberous sclerosis complex.

Tuberous sclerosis complex is associated with the occurrence of cardiac rhabdomyomas that may result in life-threatening arrhythmia unresponsive to standard antiarrhythmic therapy. We report the case of an infant with multiple cardiac rhabdomyomas who developed severe refractory supraventricular tachycardia (SVT) that was successfully treated with everolimus. Pharmacological mTOR inhibition rapidly improved arrhythmia within few weeks after treatment initiation and correlated with a reduction in tumor size.

Generation of patient-derived pediatric pilocytic astrocytoma in-vitro models using SV40 large T: evaluation of a modeling workflow.

Purpose: Although pediatric low-grade gliomas (pLGG) are the most common pediatric brain tumors, patient-derived cell lines reflecting pLGG biology in culture are scarce. This also applies to the most common pLGG subtype pilocytic astrocytoma (PA). Conventional cell culture approaches adapted from higher-grade tumors fail in PA due to oncogene-induced senescence (OIS) driving tumor cells into arrest.

Class I HDAC inhibition reduces DNA damage repair capacity of MYC-amplified medulloblastoma cells.

Purpose: MYC-driven Group 3 medulloblastoma (MB) (subtype II) is a highly aggressive childhood brain tumor. Sensitivity of MYC-driven MB to class I histone deacetylase inhibitors (HDACi) has been previously demonstrated in vitro and in vivo. In this study we characterize the transcriptional effects of class I HDACi in MYC-driven MB and explore beneficial drug combinations.

Optimizing preclinical pediatric low-grade glioma models for meaningful clinical translation.

Pediatric low-grade gliomas (pLGGs) are the most common brain tumor in young children. While they are typically associated with good overall survival, children with these central nervous system tumors often experience chronic tumor- and therapy-related morbidities. Moreover, individuals with unresectable tumors frequently have multiple recurrences and persistent neurological symptoms.

Integrative multi-omics reveals two biologically distinct groups of pilocytic astrocytoma.

Pilocytic astrocytoma (PA), the most common pediatric brain tumor, is driven by aberrant mitogen-activated protein kinase signaling most commonly caused by BRAF gene fusions or activating mutations. While 5-year overall survival rates exceed 95%, tumor recurrence or progression constitutes a major clinical challenge in incompletely resected tumors. Here, we used similarity network fusion (SNF) analysis in an integrative multi-omics approach employing RNA transcriptomic and mass spectrometry-based proteomic profiling to molecularly characterize PA tissue samples from 62 patients.

Mitochondrial DNA mutations in Medulloblastoma.

To date, several studies on genomic events underlying medulloblastoma (MB) biology have expanded our understanding of this tumour entity and led to its division into four groups-WNT, SHH, group 3 (G3) and group 4 (G4). However, there is little information about the relevance of pathogenic mitochondrial DNA (mtDNA) mutations and their consequences across these. In this report, we describe the case of a female patient with MB and a mitochondriopathy, followed by a study of mtDNA variants in MB groups.

MAPK inhibitor sensitivity scores predict sensitivity driven by the immune infiltration in pediatric low-grade gliomas.

Pediatric low-grade gliomas (pLGG) show heterogeneous responses to MAPK inhibitors (MAPKi) in clinical trials. Thus, more complex stratification biomarkers are needed to identify patients likely to benefit from MAPKi therapy. Here, we identify MAPK-related genes enriched in MAPKi-sensitive cell lines using the GDSC dataset and apply them to calculate class-specific MAPKi sensitivity scores (MSSs) via single-sample gene set enrichment analysis.

Key Pharmacokinetic Parameters of 74 Pediatric Anticancer Drugs Providing Assistance in Preclinical Studies.

Novel drug treatments for pediatric patients with cancer are urgently needed. Success of drug development in pediatric oncology has been promising, but many drugs still fail in translation from preclinical to clinical phases. To increase the translational potential, several improvements have been implemented, including the use of clinically achievable concentrations in the drug testing phase.