Most of the time, when people talk about the cutting edge gene editing technology CRISPR, they are actually talking about CRISPR-Cas9. CRISPR, you see, is just one half of the genome editing tool, the programming that instructs where a DNA edit will actually be made. The other part consists of proteins that actually do the cutting. And one particular protein, called Cas9, has long been the snipping tool of choice. But now, there's a new protein on the block — and it may open the door to curing a devastating genetic disease.
Cardiomyocytes from patients with Duchenne muscular dystrophy corrected by CRISPR-Cpf1. Image: Science Advances
Scientists have long suspected that another protein, Cpf1, might actually be superior to Cas9 because it is a smaller, simpler enzyme. And now, for the first time, scientists have successfully used it to edit human cells.
In a new paper out Wednesday in Science Advances, researchers from the University of Texas detail using CRISPR-Cpf1 to correct mutations associated with Duchenne muscular dystrophy, a disease that results in muscular degeneration. In human heart muscle cells, the researchers were able to correct key mutations and prevent disease progression. And in mice with the disease, they were able to reverse symptoms like inflammation.
The authors note that CRISPR-Cpf1 may actually be more successful at targeting Duchenne muscular dystrophy, by accessing mutation sites the more unwieldy Cas9 can't access. Cpf1, they said, could be a powerful new tool in the CRISPR arsenal. There are many different mutations associated with human disease, and not every mutation is compatible with Cas9. But some of those, as in the case of Duchenne, might be compatible with Cpf1.
In the midst of an ongoing legal battle over who owns the rights to CRISPR-Cas9, the new study highlights the fact that pace at which science moves may make today's legal skirmishes far less relevant before they are ever settled. In 2015, the Broad Institute first suggested that CRISPR-Cpf1 might be a superior system. There are also a slew of other CRISPR alternatives in the works. In May, Chinese researchers published a controversial paper on NgAgo, an entirely new system that they said can also be used to edit mammalian DNA. In June, researchers from several universities announced the discovery of C2c2, a CRISPR enzyme that targets RNA, rather than DNA. And just before Christmas, researchers at Berkeley announced the discovery of two new CRISPR/Cas systems, CRISPR-CasX and CRISPR-CasY.
Most importantly, though, the study paves the way for more research into how Cpf1 might be used to cure diseases and conditions that even CRISPR-Cas9 has so far not yet been able to tackle.