Beyond Base Camp: Promise and Pitfalls of PI3K/mTOR Inhibition in Pediatric High- Grade Gliomas.

Background: High-grade gliomas (HGGs), including diffuse midline glioma (DMG), represent the most aggressive and deadly pediatric brain cancers. Despite recent advances in understanding their molecular underpinnings, these tumors remain universally fatal. A hallmark feature of pediatric HGGs is the frequent presence of mutations and amplifications in components of the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) signaling pathway.

Establishing a living biobank of pediatric high-grade glioma and ependymoma suitable for cancer pharmacology.

Background: Brain tumors are the deadliest solid tumors in children and adolescents. Most of these tumors are glial in origin and exhibit strong heterogeneity, hampering the development of effective therapeutic strategies. In the past decades, patient-derived tumor organoids (PDT-O) have emerged as powerful tools for modeling tumoral cell diversity and dynamics, and they could then help define new therapeutic options for pediatric brain tumors.

Fusion-negative rhabdomyosarcoma 3D organoids to predict effective drug combinations: A proof-of-concept on cell death inducers.

Rhabdomyosarcoma (RMS) is the main form of pediatric soft-tissue sarcoma. Its cure rate has not notably improved in the last 20 years following relapse, and the lack of reliable preclinical models has hampered the design of new therapies. This is particularly true for highly heterogeneous fusion-negative RMS (FNRMS).

SMAD2/3 mediate oncogenic effects of TGF-β in the absence of SMAD4.

TGF-β signaling is involved in pancreatic ductal adenocarcinoma (PDAC) tumorigenesis, representing one of the four major pathways genetically altered in 100% of PDAC cases. TGF-β exerts complex and pleiotropic effects in cancers, notably via the activation of SMAD pathways, predominantly SMAD2/3/4. Though SMAD2 and 3 are rarely mutated in cancers, SMAD4 is lost in about 50% of PDAC, and the role of SMAD2/3 in a SMAD4-null context remains understudied.

Complex Elucidation of Cells-of-Origin in Pediatric Soft Tissue Sarcoma: From Concepts to Real Life, Hide-and-Seek through Epigenetic and Transcriptional Reprogramming.

Soft tissue sarcoma (STS) comprise a large group of mesenchymal malignant tumors with heterogeneous cellular morphology, proliferative index, genetic lesions and, more importantly, clinical features. Full elucidation of this wide diversity remains a central question to improve their therapeutic management and the identity of cell(s)-of-origin from which these tumors arise is part of this enigma. Cellular reprogramming allows transitions of a mature cell between phenotypes, or identities, and represents one key driver of tumoral heterogeneity.

H3.3K27M Mutation Controls Cell Growth and Resistance to Therapies in Pediatric Glioma Cell Lines.

High-grade gliomas represent the most lethal class of pediatric tumors, and their resistance to both radio- and chemotherapy is associated with a poor prognosis. Recurrent mutations affecting histone genes drive the tumorigenesis of some pediatric high-grade gliomas, and H3K27M mutations are notably characteristic of a subtype of gliomas called DMG (Diffuse Midline Gliomas). This dominant negative mutation impairs H3K27 trimethylation, leading to profound epigenetic modifications of genes expression.

Depicting the genetic architecture of pediatric cancers through an integrative gene network approach.

The genetic etiology of childhood cancers still remains largely unknown. It is therefore essential to develop novel strategies to unravel the spectrum of pediatric cancer genes. Statistical network modeling techniques have emerged as powerful methodologies for enabling the inference of gene-disease relationship and have been performed on adult but not pediatric cancers.

Tc-A1 as a Novel Imaging Agent Targeting Mesothelin-Expressing Pancreatic Ductal Adenocarcinoma.

Unlabelled: Mesothelin is a membrane-associated protein overexpressed in pancreatic ductal adenocarcinoma (PDAC). Some mesothelin-targeted therapies are in clinical development but the identification of patients eligible for such therapies is still challenging. The objective of this study was to perform the imaging of mesothelin in mice models of PDAC with a technetium-labeled anti-mesothelin single-domain antibody (Tc-A1).