GSE184934
A Novel Mouse Model of Diffuse Midline Glioma Initiated in Neonatal Oligodendrocyte Progenitor Cells Highlights Cell- of-origin Dependent Effects of H3K27M I
Diffuse midline glioma (DMG) is a type of lethal brain tumor that develops mainly in children. The majority of DMG harbor the K27M mutation in histone H3. Oligodendrocyte progenitor cells (OPCs) in the brainstem are candidate cells-of-origin for DMG, yet there is no genetically engineered mouse model of DMG initiated in OPCs. Here, we used the RCAS/Tv-a avian retroviral system to generate DMG in Olig2-expressing progenitors and Nestin-expressing progenitors in the neonatal mouse brainstem. PDGF-A or PDGF-B overexpression, along with p53 deletion, resulted in gliomas in both models. Exogenous overexpression of H3.3K27M had a significant effect on tumor latency and tumor cell proliferation when compared with H3.3WT in Nestin+ cells but not in Olig2+ cells. Further, the fraction of H3.3K27M-positive cells was significantly lower in DMGs initiated in Olig2+ cells relative to Nestin+ cells, both in PDGF-A and PDGF-B-driven models, suggesting that the requirement for H3.3K27M is increased when tumorigenesis is initiated in Nestin+ cells.  Therefore, we need to find how the tumorigenic effects of H3.3K27M are more oncogenic in Nestin+ cells than Olig2+ cells. Overall design: Five independent tumors with H3.3K27M (PaKC) and three independent tumors without H3.3K27M (PaHC) were snap frozen, RNA extracted, and RNAseq analysis was performed (PDGF-A; H3.3K27M; p53 loss vs. PDGF-A; H3.3WT; p53 loss)