Gene-editing technology has made a big step forward thanks to scientists at the Broad Institute of MIT and Harvard. This opens the door for possible therapeutic uses to treat various genetic conditions.
This exciting progress, led by David Liu's lab, includes a new way to add or change whole genes in human cells effectively.
Revolutionary Gene-Editing Technique: eePASSIGE
The new method, eePASSIGE, uses prime editing and powerful recombinase enzymes. Prime editing lets you precisely change up to 100 or 200 base pairs of DNA, and modified recombinase enzymes can add long pieces of DNA, up to thousands of base pairs long, to specific spots in the genome. This method is much more efficient than previous ones, making it possible to make changes to genes several times better than before. The work was published in the respected journal Nature Biomedical Engineering.
David Liu, the study's main author and a well-known expert in gene editing, stressed how this discovery could be used in medicine. Liu says that if the great results seen in growing human cells can be repeated in real life, this discovery could help or cure many genetic diseases where genes don't work right.
As co-first authors of the study, graduate student Smriti Pandey and fellow researcher Daniel Gao discussed how flexible eePASSIGE is. Pandey talked about the useful uses of cell therapies, where genes can be carefully added to cells outside the body before they are given to patients.
Gao was excited about how well and in how many ways eePASSIGE could be used. He said it could open the door to a new type of genomic medicine and be a valuable tool for scientists investigating basic biology questions.
Improvements to Prime Editing and Hopes for the Future
In the past, prime editing was used to fix harmful DNA, quickly changing up to dozens of base pairs long. However, putting whole, healthy genes where they normally belong in the genome was still hard. Liu's lab had already created a method called twinPE, which paved the way for this new method by adding recombinase "landing sites" to the genome and using natural recombinase enzymes like Bxb1 to speed up the addition of new DNA.
Even though it initially worked, the original PASSIGE method wasn't very good at editing. It was enough to treat some genetic diseases caused by gene loss, but not all of them. Liu's group used phage-assisted continuous evolution (PACE) to make better forms of the Bxb1 recombinase enzyme.
The engineered variant, eeBxb1, improved the eePASSIGE method significantly. It could insert gene-sized cargo into about 30% of mouse and human cells, four times better than the original method and sixteen times better than a more modern method called PASTE.
Liu emphasized the importance of this progress by saying that eePASSIGE gives us an excellent way to place healthy copies of genes exactly in cell and animal models of genetic diseases. The group thinks this method will be critical for patients to benefit from the healing benefits of precise gene integration.
In the future, Liu's team will work on mixing eePASSIGE with more advanced ways to deliver drugs, such as engineered virus-like particles (eVLPs). These systems might overcome the problems that have prevented gene editors from entering the body, bringing us closer to finding valuable treatments for many genetic diseases.
eePASSIGE is a huge step forward in the method used to change genes. It could change how genetic diseases are handled and give millions of people worldwide hope.
Read also: In Vivo Gene Editing: Scientists Use CRISPR Technology to Modify DNA Inside a Person's Body
Check out more news and information on gene editing in Science Times.
