Path-09. subtype-associated rna splicing controlled by glioma driver mutations regulates gliomagenesis

Abstract Dysregulated RNA alternative splicing (AS) is a hallmark of cancer and has been studied in cancers including glioma. However, whether the dysregulated AS and the regulating RNA-binding proteins (RBPs) drive gliomagenesis and the role of glioma driver mutations in shaping the RBP/AS landscape have not been studied. Here we describe two AS-defined glioma subtypes that correlate with IDH1 mutation, tumor grade, and patient prognosis. Oncogenic AS isoforms are exclusively associated with AS subtype 2, IDH1 wild-type gliomas. Modulation of representative AS isoforms or subtype-associated RBPs regulate glioma stem-like cell (GSC) tumorgenicity. With a human induced pluripotent stem cell-derived glioma model system, we demonstrate that specific glioma driver mutations are involved in shaping the subtype-associated AS. Lastly, we target a sub2-associated RBP with anti-sense oligonucleotides to inhibit GSC tumorigenicity. Our data establish relationships between glioma driver mutations and AS programs and identify dysregulated RBP/AS network as a therapeutic vulnerability.