Next Generation Sequencing Quantitative Analysis of Wild Type and NONO Knock Down Glioblastoma Cell Line (GSC P3) Transcriptomes

We identified non-POU domain-containing octamer-binding protein (NONO), a Drosophila behavior human splicing (DBHS) protein, among the most upregulated mRNA splicing factors in glioblastoma multiforme (GBM). NONO was associated with poor prognosis in GBM patients, and overexpression of NONO promoted GBM cell proliferation, invasion and tumorigenesis in a GBM orthotopic xenograft model. Through RNA sequencing based transcriptomic profiling, we found that knockdown of NONO resulted in global changes in alternative splicing-intron retention, and identified GPX1 and CCN1 as two pre-mRNAs targeted by NONO. NONO directly bound to the intron of GPX1 pre-mRNA through the RNA-recognition motifs 2 (RRM2) domain and required interaction with another DBHS protein family member, PSPC1. Knockdown of NONO interfered with redox homeostasis in cells, at least partially, through abnormal splicing of GPX1. Finally, Auranofin, a small-molecule inhibitor targeting NONO, inhibited GBM growth in an orthotopic xenograft model in mice. Taken together, our data revealed that NONO was a key regulator of mRNA splicing in GBM, and that targeting NONO represents a novel and effective therapeutic strategy for the treatment of GBM. Glioblastoma cell line P3 mRNA profiles of wild type (siNC) and NONO Knock Down (siNONO) cell line