Gene therapy requires "gene precise editing" that accurately modifies only the desired genes. Domestic researchers have improved the efficiency of gene precise editing, which had low success rates, by inducing autophagy within cells for the first time in the world.
Nam Hye-jin, a principal researcher at the Korea Research Institute of Chemical Technology, noted on the 25th that her team, in collaboration with professors Cho Dong-hyun and Bae Sang-soo from Seoul National University College of Medicine, significantly increased gene correction efficiency through various autophagy induction methods. This research was published in the international journal "Nucleic Acids Research" in April.
Gene scissors (CRISPR–Cas9) are an innovative technology that uses the "Cas9" enzyme to cut DNA for gene correction. However, the process of repairing DNA at the cut sites is mostly inaccurate, resulting in very low efficiency of "precise correction (HR)" for accurately modifying genes as desired. While various methods have emerged to improve this, there were limitations due to issues such as toxicity, side effects, and restrictions in application scope.
The research team focused on the point that the process of "autophagy," which removes and recycles damaged components in cells, could affect precise correction. Starved cells secrete proteins that influence DNA damage repair during the autophagy process, and appropriately inducing this increased the efficiency of precise correction.
First, they induced autophagy by providing only saline with no nutrients to the cells or by administering growth signal inhibitors. As a result, various key co-factors acting on DNA damage repair gathered significantly around the gene scissors enzyme, "Cas9." The analysis found that in cells where autophagy was induced, the efficiency of precise correction increased by 1.4 to 3.1 times, and consistently improved performance regardless of the size of the DNA to be inserted or the expression level of the target gene.
Meaningful results were also obtained in disease model experiments. When the technology was applied to cells derived from patients with a mutation in the hearing impairment gene "MPZL2," the expression levels of the introduced normal ribonucleic acid (RNA) increased.
To verify whether this technology is effective beyond the cellular level, experiments were conducted using mice's retinal pigment epithelium tissues. When DNA containing the Cas9 gene scissors and the fluorescent protein gene was injected into the subretinal layer of the mice, and autophagy inducers were simultaneously administered into the eye, gene correction was successfully carried out. This confirmed for the first time that autophagy induction promotes precise correction even in a living environment.
Moreover, the same effect was observed in modified versions of conventional gene scissors, such as nickase Cas9 (nCas9) and inactive Cas9 (dCas9), demonstrating that this technology can be applied to various gene editing platforms.
The research team said, "The increase in efficiency of precise correction using autophagy is a revolutionary method that can overcome the limitations of various existing gene correction technologies" and added, "We plan to enhance the technology through follow-up research to utilize this technology for correcting various disease-related genes."
References
Nucleic Acids Research (2025), DOI: https://doi.org/10.1093/nar/gkaf258