CRISPR Phenotypic enrichment screen for epigenetic regulators of MEIS1 expression in acute myeloid leukemia (AML) [CRISPRScreens]

We perfomed CRISPR screens to investigate the upstream epigenetic regulators of MEIS1 expression, using a pooled CRISPR library targeting chromatin modifiers (~600 genes). We constructed the pooled library and used it to transduce U937 cells modified with a GFP knock-in in the MEIS1 locus. The cells were sampled at "Day 0" and kept in culture for 5 days, then sorted to harvest the top- and bottom- 20% fractions by GFP signal. Genomic DNA was then prepared from each fraction, as well as the Day 0 sample. We then performed library preparation and next generation sequencing to compare the relative abundance of sgRNA sequences in the fractions of interest. Overall design: Examination of sgRNA abundance in sorted fractions on the basis of GFP-MEIS1 expression in the U937 AML cell line.