A revolutionary new strategy strengthens CRISPR editing, minimizing large deletions and improving the safety and precision of genetic modifications. Credit: 2024 KAUST
KAUST researchers have improved the safety of CRISPR gene editing by reducing harmful DNA deletions and improving repair mechanisms, advancing safer genetic treatments.
A simple, robust strategy developed by KAUST scientists could help improve safety and precision of CRISPR gene editing, a tool already approved for clinical use to treat inherited blood disorders.
This approach solves a critical problem with CRISPR technology: cutting the genome at specific points and splicing it back together, which inherently poses the risk of genome damage. DNA in a way that could cause major and unpredictable disruptions.
Hoping to alleviate this problem, a team led by Mo Li, a stem cell biologist at KAUST, studied the DNA repair pathways that lead to large genomic deletions after CRISPR editing in human strains.
Their analysis led them to a process known as microhomology-mediated end-joining (MMEJ), an error-prone mechanism that, while it can repair DNA breaks, often leaves significant deletions behind.
Major genetic discoveries
The researchers investigated the various genes involved in this MMEJ process and found two that played a central—but opposite—role in these unwanted repression events.
Gene, the so-called POLQ, has been shown to increase the risk of large deletions after CRISPR editing. The second, the so-called APRemerged as a genomic gatekeeper with protective effects.
By manipulating these genes, either with drugs that inhibit them POLQ or through genetic techniques that stimulate expression APRthe KAUST team was then able to reduce the occurrence of deleterious large deletions without compromising the efficiency of genome editing and, in doing so, preserve the genomic integrity of the edited stem cells.
“This easy-to-use approach could reduce the risks of large, harmful DNA deletions,” says Baolei Yuan, a former Ph.D. student in Lee’s lab and one of the architects of the study, along with Chongwei Bi and Yeteng Tian of Lee’s lab.
Improve repair mechanisms
In addition, these same interventions have been shown to improve the efficiency of homology-directed repair, a mechanism known for its ability to enable precise genome editing without adding unwanted mutations.
This was evident in experiments involving stem cells carrying mutations in two genes associated with sickle cell anemia and Wiskott-Aldrich syndrome, two inherited blood disorders. By modulating POLQ Or APRthe researchers carried out very precise and reliable gene editing in these cells.
The results mark a significant step forward in refining CRISPR technology, Li says. “That’s really exciting, because it means we’re getting closer to safer and more effective treatments for genetic diseases,” he says.
With a provisional patent application filed for this innovative strategy, the team continues to investigate the mechanisms behind a wider range of unwanted mutations and refine their techniques to make CRISPR safer and more effective.
“Achieving high efficiency and safety remains a challenge that requires further development,” says Li, “and our laboratory remains at the forefront, seeking innovative solutions. »