A new gene editing technique called prime editing, tested in human and mouse cells, rewrites DNA by only cutting a single strand to add, remove, or replace base pairs. The method may allow researchers to edit more types of genetic mutations than existing genome-editing approaches such as CRISPR-Cas9, researchers report today (October 21) in Nature.
Emma Haapaniemi, a group leader at the Center for Molecular Medicine Norway who studies gene editing to treat rare diseases and wasn’t part of the work to develop prime editing, tells The Scientist that the approach is “innovative and novel,” though of course, the technique is “still a prototype” and will need to be refined.
The discovery that CRISPR-Cas9 could be harnessed and used to edit animal and human genes ushered in a new era of genetic research over the past several years. The technique has become an indispensable tool in many research laboratories, allowing scientists to more easily create animal models of genetic diseases. While CRISPR-Cas9 has been making its way toward the clinic, its practical use in curing human disease has been limited by ethical considerations, challenges with delivery, and precision—in particular, so-called off-target effects that alter DNA at unintended loci in the genome.
The CRISPR-Cas9 gene editing system has been known to produce extra cuts in wrong sections of DNA, which can interrupt cell function. Another type of gene editing that doesn’t rely on DNA breaks and was thought to minimize inaccuracy is base editing, in which an enzyme can trade one DNA nuclease for another, but this strategy offers limited options as it can only make four of the 12 possible base pair changes, and some recent work has suggested it’s not as precise as scientists first thought.
When postdoc and lead author of the study Andrew Anzalone joined David Liu’s lab at the Broad Institute, which previously developed the technique for base editing, he was especially excited by the possibility of editing genes without using DNA breaks…
