H3.3 G34R-engineered murine glioma reproduces diffuse perineuronal infiltration of diffuse hemispheric glioma, H3 G34-mutant.

Abstract

BACKGROUND: Diffuse hemispheric glioma, H3 G34-mutant (DHG-H3G34), is an aggressive pediatric brain tumor characterized by a distinctive neurotropic invasion pattern, including prominent perineuronal satellitosis (PS). The molecular mechanisms underlying this phenotype remain unclear owing to the scarcity of faithful preclinical models. METHODS: A murine glioma model was generated by introducing the H3.3 G34R mutation into SV40-immortalized glial cells (IG34). Transcriptomic profiling was used for molecular characterization, and in vivo behavior was assessed following orthotopic implantation into immunodeficient mice. RESULTS: IG34&#x202f;cells exhibited stable expression of the H3.3 G34R oncohistone. Transcriptomic analysis revealed upregulation of interferon-response genes and positive normalized enrichment scores across multiple oncogenic signatures, with a subset reaching statistical significance (FDR <0.25). In vivo, IG34&#x202f;cells formed diffusely infiltrative tumors. PS was significantly increased compared with controls, whereas perivascular satellitosis did not differ significantly, thus recapitulating the selective neurotropic invasion characteristic of DHG-H3G34. CONCLUSIONS: Our H3.3 G34R-engineered murine model successfully reproduces the defining neurotropic features of human DHG-H3G34, particularly PS. This pathologically relevant model provides a valuable platform for investigating the molecular basis of glioma invasion and for guiding the development of therapeutic strategies.