Unmet Need
The CRISPR/Cas9 system is a revolutionary genome editing tool that has opened up new opportunities in biological research and disease treatments. However, prolonged activity of Cas9 endonuclease inside the cell could undermine the efficacy of this system as it increases the risk of deleterious side-effects, such as off-target editing, genotoxicity, and chromosomal translocations. Although approaches have been developed to deactivate Cas9 activity, these approaches require delivery of extrinsic molecules such as small molecule inhibitors, and researchers don’t have control over the duration and location of the deactivation. Precise spatiotemporal modulation over Cas9 deactivation is essential for enabling more precise genome editing with fewer unintended perturbations.
Technology Overview
Johns Hopkins researchers have developed a CRISPR/Cas9 system with a built-in off-switch such that Cas9 can be rapidly and irreversibly deactivated with high spatiotemporal precision. Their system significantly enhanced targeting specificity and exhibited uncompromised on-target activity in cells compared to the conventional system. Of note, their system deactivated Cas9 activity within seconds and with millimeter precision. Furthermore, the inventors demonstrated that their platform displayed similar efficacy to single nucleotide base editors, another system that utilizes the Cas9 endonuclease.
Stage of Development
This technology is fully developed and validated for in vitro research applications. Further validation will be needed before use in therapeutic applications.
Publications
Zou RS, Marin-Gonzalez A, Liu Y, Liu HB, Shen L, Dveirin RK, Luo JXJ, Kalhor R, Ha T. Massively parallel genomic perturbations with multi-target CRISPR interrogates Cas9 activity and DNA repair at endogenous sites. Nat Cell Biol. 2022 Sep;24(9):1433-1444.
