DNA Replaced Intact Without Cutting It... New Path Opens for Treating Rare Genetic Diseases

[Financial News] A next-generation biotechnology has been developed to treat intractable diseases caused by genetic abnormalities. Instead of dangerously cutting DNA with gene-editing scissors, the technology replaces an entire defective section with a normal gene. Because it can replace a block of normal genetic material at once, rather than correcting each patient's unique mutation individually, it is expected to mark a major turning point in developing treatments for rare genetic diseases.
A joint research team led by Gue-Ho Hwang, a professor in the Department of Chemistry at Hanyang University, and Daniel E. Bauer of Harvard Medical School announced on the 18th that it had developed Prime Assembly, a technology that accurately inserts large genes of up to 12,100 bases into desired locations without cutting DNA. The findings were published in Nature, one of the world's most prestigious international scientific journals.
The widely used CRISPR gene-editing tools work by cutting through both strands of DNA. As cells repair the resulting damage on their own, unintended mutations can occur. In addition, normal genes could be inserted only when cells were actively dividing, making the technology difficult to apply to nondividing, resting cells such as stem cells and immune cells, which are essential for actual treatments.
The researchers brought a laboratory assembly technique, in which multiple DNA fragments are fitted together like puzzle pieces, into living cells. Rather than cutting through a DNA strand, the method makes a slight nick in just one strand and sequentially inserts normal DNA fragments designed to fit precisely into the opening. The cell's own repair enzymes then naturally fill the gap, joining the long genetic sequence into a single unit.
In experiments, the team successfully inserted DNA as long as 12,100 bases into the target location with high precision. The technology was more accurate than existing methods, substantially reducing mutations at the junctions. Gene editing also proceeded normally in resting immune cells that had stopped dividing, further increasing the prospects for commercializing treatments.
The researchers also developed CRISPRlungo, dedicated analysis software for checking whether genetic surgery was completed safely. The program reads long genetic sequences at once and accurately detects errors, such as inverted genes or genes cut away at unintended locations. It can be used immediately by anyone through a web browser without installing separate software, greatly expanding its usefulness to bioresearchers worldwide. This achievement was published in Nature Biomedical Engineering, an international journal in the field of biomedical engineering.
Gue-Ho Hwang said, "As we can now replace an entire gene without cutting it, a path has opened to address rare genetic diseases, whose mutations vary from patient to patient, with a single technology." He added, "Because new genetic surgery techniques can lead to actual treatments only when their results are read precisely and verified to be free of side effects, we will combine the two technologies to accelerate the development of treatments."

[email protected] Kim Man-gi Reporter