A PNA-based gene editing technique can improve gene detection

In an article published in the journal Nature, The National Institutes of Health, Somatic Cell Gene Editing Consortium provided detailed information on the progress of their efforts across the country to develop safer and more efficient methods for editing somatic cell genomes relevant to disease and reducing the burden of disease caused by genetic changes.

Gene editing allows scientists to modify parts of an organism’s DNA and is considered a promising treatment for a number of genetic diseases. Numerous laboratory advances have been made in recent decades, but there are still many challenges that need to be overcome before gene editing can be widely used in the patient population.

Launched in 2018, the Somatic Cell Gene Editing Consortium (SCGE) brought together some of the leading researchers in the field to advance the discovery and accelerate the transition of somatic gene editing in the laboratory to the clinical setting.

In six years, the NIH will allocate approximately $ 190 million to SCGE to realize the potential for gene editing. The end result will be a freely available tool, which will provide the biomedical research community with rigorously assessed information on genome editors and methods for delivering and monitoring gene editing molecules.

The NIH has realized that it is important for all of us who research gene editing to work together on a common goal. We design molecules that can enter a cell and catalog all of them individually. What we will end up with is a very valuable, rigorously assessed resource for those who want to bring gene editing to patients. “

Danith Ly, Professor, Chemistry, Carnegie Mellon University

Ly joined the 2019 consortium. Although most of the consortium’s work focuses on CRISPER-Cas-related systems, SCGE emphasizes the importance of continuing to develop other systems. They particularly single out a peptide nucleic acid-based gene editing technique developed by Carnegie Mellon of Ly and Peter Glazer of Yale University.

“Although within SCGE there is a significant focus on CRISPR-Cas-related systems, it is crucial to continue to explore alternative systems, in part because they may differ both in delivery potential and in biological or immune responses,” the consortium wrote in Nature.

While CRISPR-Cas regulates genes in cells removed from the body, the Ly and Glazer peptide nucleic acid (PNA) system is administered intravenously and regulates cells in vivo. Using nanoparticles, a PNA molecule paired with a donor DNA strand is delivered directly to the defective gene.

Ly, a leading researcher in synthetic nucleic acid technology, has programmed PNA molecules to open double-stranded DNA at the site of a targeted mutation. The donor DNA from the complex binds to the defective cell DNA and triggers an innate DNA repair mechanism to regulate the gene. The team used a technique to treat beta thalassemia in adult mice and in fetal mice in utero.

The PNA gene editing system does not have the high yield of the CRISPER-Cas system, but has the advantage that it is less likely to make modifications outside the target. According to Lyu, this means that their technique could be better for genetic diseases that require only a small percentage of cells corrected to achieve a therapeutic difference.

For example, in studies of beta thalassemia, Ly and Glazer found that editing only six to seven percent of cells is curative.

Ly and Glazer plan to further refine and improve their technique through their participation in SCGE, and look forward to sharing their results with the consortium and the larger biomedical community.


Carnegie Mellon University

Journal reference:

Saha, K., and others. (2021) NIH somatic cell genome editing program. Nature. doi.org/10.1038/s41586-021-03191-1.