Current Landscape of Preclinical Models for Pediatric Gliomas: Clinical Implications and Future Directions

Abstract

Pediatric high-grade gliomas (pHGGs), particularly diffuse midline gliomas (DMGs), are among the most lethal brain tumors due to poor survival and resistance to therapies. DMGs possess a distinct genetic profile, primarily driven by hallmark mutations such as H3K27M, ACVR1, and PDGFRA mutations/amplifications and TP53 inactivation, all of which contribute to tumor biology and therapeutic resistance. Developing physiologically relevant preclinical models that replicate both tumor biology and the tumor microenvironment (TME) is critical for advancing effective treatments. This review highlights recent progress in in vitro, ex vivo, and in vivo models, including patient-derived brain organoids, genetically engineered mouse models (GEMMs), and region-specific midline organoids incorporating SHH, BMP, and FGF2/8/19 signaling to model pontine gliomas. Key genetic alterations can now be introduced using lipofectamine-mediated transfection, PiggyBac plasmid systems, and CRISPR-Cas9, allowing the precise study of tumor initiation, progression, and therapy resistance. These models enable the investigation of TME interactions, including immune responses, neuronal infiltration, and therapeutic vulnerabilities. Future advancements involve developing immune-competent organoids, integrating vascularized networks, and applying multi-omics platforms like single-cell RNA sequencing and spatial transcriptomics to dissect tumor heterogeneity and lineage-specific vulnerabilities. These innovative approaches aim to enhance drug screening, identify new therapeutic targets, and accelerate personalized treatments for pediatric gliomas.

Keywords: GEMMs; diffuse midline gliomas; immunocompetent mouse model of DMGs; in utero electroporation; pHGGs.

Figure 1

In vivo pediatric brain tumor modeling strategies. Multiple in vivo approaches have been developed to model pediatric high-grade gliomas (pHGGs), including diffuse midline gliomas (DMGs), to better understand tumor biology and therapeutic responses. Among these, in utero electroporation (IUE)-based GEMMs have emerged as a powerful system, enabling precise delivery of glioma-driving genetic alterations into neural progenitors during embryonic development, resulting in tumors that closely mimic the molecular and histopathological features of human disease. Additional models include Sleeping Beauty (SB) transposon-based approaches and RCAS-Tv-a and Cre-loxP transgenic systems, as well as orthotopic transplantation of murine-derived or patient-derived glioma cells into immunocompetent or immunocompromised mouse brains. Zebrafish models utilize xenograft (a) and syngeneic (b) strategies, including ZFN (zinc finger nuclease) or TALEN (transcription activator-like effector nuclease) mRNA injection into 1-cell embryos or the re-implantation of zebrafish brain tumor cells into adult Casper fish for tumor progression studies (created with BioRender.com).

Figure 2

In vitro pediatric glioma modeling strategies. Advanced in vitro platforms, including cerebral organoids, tumor-derived organoids, neurospheres, and 3D spheroids, are used to model pediatric high-grade gliomas (pHGGs) and their tumor microenvironment (TME). Glioma–brain organoids, microfluidic devices, and 3D bioprinting further enable dynamic modeling of tumor–immune–brain interactions and therapeutic responses. These models also facilitate the study of region-specific gliomas with distinct genetic mutations, such as H3K27M or H3G34R (created with BioRender.com).