Dissecting the impact of regional identity and the oncogenic role of human-specific NOTCH2NL in an hESC model of H3.3G34R-mutant glioma

• Published in: Cell stem cell 2021-05, Vol.28 (5), p.894-905.e7
• Main Authors: Funato, Kosuke, Smith, Ryan C., Saito, Yuhki, Tabar, Viviane
• Format: Article
• Language: English
• Subjects: ATRX; Brain Neoplasms - genetics; cancer models; Glioma - genetics; H3.3G34R; high-grade glioma; hindbrain progenitors; histone-mutant glioma; Histones - genetics; Human Embryonic Stem Cells; Humans; interneuron progenitors; Mutation - genetics; NOTCH2NL; Oncogenes; Pluripotent stem cells; TP53; ventral forebrain
• ISSN: 1934-5909; 1875-9777
• DOI: 10.1016/j.stem.2021.02.003

H3.3G34R-mutant gliomas are lethal tumors of the cerebral hemispheres with unknown mechanisms of regional specificity and tumorigenicity. We developed a human embryonic stem cell (hESC)-based model of H3.3G34R-mutant glioma that recapitulates the key features of the tumors with cell-type specificity to forebrain interneuronal progenitors but not hindbrain precursors. We show that H3.3G34R, ATRX, and TP53 mutations cooperatively impact alternative RNA splicing events, particularly suppression of intron retention. This leads to increased expression of components of the Notch pathway, notably NOTCH2NL, a human-specific gene family. We also uncover a parallel mechanism of enhanced NOTCH2NL expression via genomic amplification of its locus in some H3.3G34R-mutant tumors. These findings demonstrate a novel mechanism whereby evolutionary pathways that lead to larger brain size in humans are co-opted to drive tumor growth. [Display omitted] •H3.3G34R, ATRX, and TP53 mutations transform forebrain but not hindbrain precursors•Triple-mutant hESC-derived ventral forebrain progenitors show alternative mRNA splicing patterns•Increased expression of human-specific NOTCH2NL in triple-mutant ventral forebrain progenitors•The NOTCH2NL locus is amplified in H3.3G34R-mutant high-grade glioma A human embryonic stem cell model of H3.3G34R-mutant gliomas was developed by Tabar and colleagues. The model identifies ventral forebrain interneuron progenitors as putative cells of origin and reveals a role for alternative mRNA splicing and NOTCH2NL in tumorigenesis.