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. Examination of sgRNA abundance in sorted fractions on the basis of GFP-MEIS1 expression in the U937 AML cell line.