Functional Identification of Critical Bmi1 target genes in Neural Progenitor and Malignant Glioma cells

In this study, we combined a genome-wide analysis of the Polycomb protein Bmi1 and an in vivo RNAi screening to identify critical targets whose repression in neural progenitor and Malignant Glioma cells enables normal and aberrant self-renewal. Overall design: Bmi1 ChIP-sequencing generated in 2 primary adult mouse Neural Progenitor cell lines, 1 mouse astrocytic cell line, 1 mouse Glioma initiating cell line, and 1 mouse Glioma cell line. In human cell lines, Bmi1 ChIP-seq was performed for foetal Neural Progenitor Cells, and 2 Glioblastoma Stem-like cells. ChIP-seq for AP-1 in one Glioblastoma stem-like cell line. ChIP-sequencing were generated using either Illumina GxII or HiSeq. We have further performed RNA-seq of adult Ink4a/Arf -/-;BMI1or GFP dox-inducible shRNA mNPC with a doxycycline inducible shRNA targeting BMI1 or GFP (as control). These cells were either treated with doxyclyine for 48h to ablate BMI1 and GFP expression or further subjected to short-term differentiation using either BMP4 (10ng/ml or 50ng/ml for 3 or 6hrs), or FBS (1 or 10% for 3 or 6hrs). Additional mouse RNA-seq were performed in two biological replica of adult mouse brains (littermate) with either wild-type FVB background or BMI1 -/-. Finally, we performed RNA-seq in human Glioblastoma stem-like cells (most likely belonging to the mesenchymal GBM subtype) treated with BMP7, Arvanil and doxycycline or EtOH treated as ctrl.