Optimizing in utero electroporation of the developing mouse pons to model diffuse midline glioma

The leading cause of brain cancer-related death in children is diffuse midline glioma (DMG). A particularly aggressive DMG subtype is pediatric diffuse intrinsic pontine glioma (DIPG), which is caused by the histone mutation H3.3K27M. Because of its diffuse growth and location in a critical brainstem structure, therapeutic options are limited and DIPG is considered universally fatal. Lack of appropriate animal models has hindered our understanding of the developmental origins and progression of DIPG, which in turn has limited development of effective therapeutics. To address this barrier, we optimized an in utero electroporation method to model DIPG in vivo in the developing mouse pons. In this protocol, we use in utero electroporation to express canonical DIPG mutant oncogenes in neural progenitors lining the 4th ventricle, which give rise to cells in the pons. As the embryos continue to develop in utero and then postnatally, they develop large diffuse brainstem tumors with molecular characteristics of pediatric DIPG, allowing us to model the formation and progression of this deadly pediatric brain cancer.