Dual direction CRISPR transcriptional regulation screening uncovers gene networks driving drug resistance

Area of Science:

• * CRISPR-Cas9 gene editing technologies
• * Cancer drug discovery and resistance mechanisms

Background:

• * Pooled CRISPR-Cas9 knockout (CRISPRko) screens are effective for drug target identification but can yield false positives from multiple DNA cleavages.
• * Nuclease-deficient Cas9 variants enable CRISPR interference (CRISPRi) for gene repression and CRISPR activation (CRISPRa) for gene overexpression.
• * Combining CRISPRko, CRISPRi, and CRISPRa offers a more comprehensive approach to functional genomics.

Purpose of the Study:

• * To directly combine CRISPRko, CRISPRi, and CRISPRa in genome-wide screens.
• * To identify genetic components influencing sensitivity and resistance to the BRAF inhibitor vemurafenib.
• * To reveal complex gene networks controlling drug response through integrated functional genomics.

Main Methods:

• * Genome-wide CRISPRko, CRISPRi, and CRISPRa screens were performed.
• * The screens were designed to identify genetic modifiers of vemurafenib response.
• * Loss-of-function (CRISPRko, CRISPRi) and gain-of-function (CRISPRa) datasets were integrated.

Main Results:

• * The combined application of CRISPRko, CRISPRi, and CRISPRa identified key regulators of vemurafenib response.
• * Integration of loss- and gain-of-function data revealed complex gene networks underlying drug sensitivity and resistance.
• * This multi-pronged CRISPR approach enhances confidence in novel drug target identification and validation.

Conclusions:

• * Directly combining CRISPRko, CRISPRi, and CRISPRa in genome-wide screens is feasible and powerful.
• * This integrated approach provides a more robust method for identifying drug targets and understanding drug resistance.
• * The study highlights the value of combining diverse CRISPR-based functional genomics strategies for drug discovery.