Genome-wide RNAi screens in human brain tumor isolates reveal a novel viability requirement for PHF5A

• DOI: 10.1101/gad.212548.112
• Publication Date: 2013-05-07T13:50:08Z
• Authors: Christopher G. Hu...; Robert K. Bradley; Yu Ding; Chad M. Toledo; Jacob Herman; Kyobi Skutt-Kakaria; Emily J. Girard; Jerry Davison; Jason Berndt; Philip Corrin; Justin Hardcastle; Ryan Basom; Jeffery J. Delrow; Thomas Webb; Steven M. Pollard; Jeongwu Lee; James M. Olson; Patrick J. Paddison
• Keywords: Viability assay; snRNP

To identify key regulators of human brain tumor maintenance and initiation, we performed multiple genome-wide RNAi screens in patient-derived glioblastoma multiforme (GBM) stem cells (GSCs). These identified the plant homeodomain (PHD)-finger domain protein PHF5A as differentially required for GSC expansion, compared with untransformed neural (NSCs) fibroblasts. Given PHF5A's known involvement facilitating interactions between U2 snRNP complex ATP-dependent helicases, examined cancer-specific roles RNA splicing. We found that GSCs, but not controls, facilitates recognition exons unusual C-rich 3' splice sites thousands essential genes. knockdown NSCs, astrocytes, or fibroblasts, inhibited splicing these genes, leading to cell cycle arrest loss viability. Notably, pharmacologic inhibition activity phenocopied GSCs also NSCs fibroblasts overexpressing MYC. Furthermore, compromised formation vivo growth established GBM xenograft tumors. Our results demonstrate a novel viability requirement maintain proper exon tumor-initiating may provide new inroads anti-GBM therapeutic strategies.