Project description:We present a CRISPR-based multi-gene knockout screening system and new toolkits for extensible assembly of barcoded high-order combinatorial guide RNA libraries en masse. We apply this system for systematically identifying not only pairwise but also three-way synergistic therapeutic target combinations, and successfully validated double and triple combination regimens for suppression on cancer cell growth and protection against Parkinson’s disease-associated toxicity. This system overcomes the practical challenges to experiment on a large number of high-order genetic and drug combinations, and is applicable for uncovering the rare synergistic interactions between druggable targets.
Project description:This is data for the evaluation of a new way of counting sgRNAs in CRISPR screens using padlock probes and UMIs. It is compared to the typical PCR-based approach. In particular, a dropout screen was performed in MiaPaCa-2 cells using the Human Kinome CRISPR pooled library (Addgene #75314)
Project description:Current protein engineering methods are inadequate to explore the combinatorial potential offered by nature’s vast repertoire of protein domains – limiting our ability to create optimal synthetic tools. To overcome this barrier, we develop an approach to create and test thousands of chimeric proteins and employ it to probe an expansive combinatorial landscape of over 15,000 multi-domain CRISPR activators. Our findings indicate that many activators produce substantial cellular toxicity, often unrelated to their capacity to regulate gene expression. We also explore the biochemical features of activation domains and determine how their combinatorial interactions shape activator behavior. Finally, we identify two potent CRISPR activators, MHV and MMH, and demonstrate their enhanced activity across diverse targets and cell types compared to the gold-standard MCP activator, synergistic activation mediator (SAM)
Project description:Chromatin regulators are frequently mutated in human cancer and are attractive drug targets. They include diverse proteins that share functional domains and assemble into related multi-subunit complexes. To investigate functional relationships among these regulators, here we apply combinatorial CRISPR knockouts (KOs) to test over 35,000 gene-gene pairings in leukemia cells, using a library of over 300,000 constructs. Top pairs that demonstrate either compensatory non-lethal interactions or synergistic lethality enrich for paralogs and targets that occupy the same protein complex. The screen highlights protein complex dependencies not apparent in single KO screens, for example MCM histone exchange, the nucleosome remodeling and deacetylase (NuRD) complex, and HBO1 (KAT7) complex. We explore two approaches to NuRD complex inactivation. Paralog and non-paralog combinations of the KAT7 complex emerge as synergistic lethal and specifically nominate the ING5 PHD domain as a potential therapeutic target when paired with other KAT7 complex member losses. These findings highlight the power of combinatorial screening to provide mechanistic insight and identify therapeutic targets within redundant networks.
