EGFRvIII overexpression and loss of mouse-specific CDKN2A in glial cells leads to spontaneous gliomagenesis in a novel mouse model

Background Glioblastoma is the most common primary brain cancer in adults, with a poor prognosis and median survival of 15 months after treatment. Few in vivo transgenic models exist for testing new therapeutics. Methods A novel mouse model for the classical subtype of human glioblastoma (GBM) has been bred using Cre-mediated EGFRvIII overexpression and homozygous p19-ARF deletion, the mouse homolog of human p14ARF/CDKN2A, in GFAP-expressing cells. Results Transgenic mice developed intraparenchymal and/or leptomeningeal brain lesions as early as 1 month old and 95% of mice succumb to endpoint symptoms of hydrocephalus and/or paralysis by 6 months. Immunohistochemical analysis confirms EGFRvIII overexpression and p19-ARF loss in Cre-expressing cells, along with patchy positive GFAP and high proliferation by Ki67 as well as loss of H3K27me3. Bulk and single cell RNA sequencing revealed tumors cluster closely with classical GBM and have significant upregulation of downstream markers in the JAK/STAT and P13K/AKT pathways as well as intratumoral heterogeneity. Dissociated tumors generated xenograft tumors by 3 weeks post intracranial injections into NOD-SCID mice and were characteristic of the primary lesion. Conclusion We developed a spontaneous, immune-competent murine glioma model that enables characterization of tumor development within an intact immune microenvironment and provides a resource for future mechanistic studies.