Scientists have created a new way of editing DNA, which seems to facilitate accurate and safe gene transcription.
A new technique called basic editing is intended to overcome some of the limitations of CRISPR. This technique, often described as a type of molecular scissor for genes, is revolutionizing research by allowing scientists to modify DNA.
"It has been proven difficult to use these molecular scissors to make exact DNA changes in most cell types," says David Liu, a biologist at Harvard, MIT and the Greater Cambridge Institute, Massachusetts.
Liu runs the lab where created the new basic editing technique in research led by Andrew Anzalone. The advance is described in the journal Nature in an article published on Monday.
One advantage of the new editing technique is that, unlike CRISPR, basic editing does not rely on the cell's ability to divide to help make the desired changes to DNA. This means that it can be used to correct genetic mutations in cells that often do not divide, such as cells in the nervous system. Many diseases are caused by mutations in genes in these cells, such as Parkinson's and Huntington's.
In addition, the new method does not cut off both strands of the DNA double helix, minimizing the chances of making unwanted changes that could be
DNA sequences and exactly replace them with edited DNA strands, "says Liu.
Liu says his team has already used the new approach to perform more than 175 human-cell edits in laboratory vessels, including fixation of genetic mutations that cause sickle cell disease and Tay-Sachs disease. Doctors are already trying to use CRISPR to treat sickle cell patients.
"Basic editing is indeed a step – and a potentially significant step – towards this long-term pursuit of an area in which we try to make just about any type of DNA change that everyone wants on almost every site in the human genome,"
The technique involves the fusion of two enzymes – one used in CRISPR known as CAS9 and another called reverse transcriptase – the combined enzymes are combined with a molecule involved in the decoding of DNA, known as RNA. An RNA called pegRNA is designed to direct pe
Other researchers agree that the new approach holds great promise.
"Basic editing can be a game changer," says Maria Jasin, a molecular biologist at Sloan-Kettering Memorial Institute for Cancer.
"It's a time to get up and cheer," agrees Fyodor Urnov, a geneticist at the University of California, Berkeley.
"For gene editors, it's a bit like a new Avenger joining our team. Someone who brings the super power that is needed in the field. He'll be excited to underestimate," Urnov says.
Urnov hopes that premiere editing will enable scientists to correct mutations that cause diseases that CRISPR cannot, such as mutations that occur in nerve cells
"If you think of CRISPR as a flight – like an airplane – then this new invention is something like a helicopter, "says Urnov. "It also flies and takes you from point A to point B. But there are specific settings – such as an accurate landing at the top of the Salesforce tower here in San Francisco – where you can imagine a helicopter would be better than
But Liu, Jasin, and Urnov emphasize that much more research will be needed to know how well the major edition works. And like any powerful new technology, it could potentially be misused.
"Gene editing, like many technologies, can, in principle, be used for insidious purposes. First editing in this regard does not pose a serious threat to the planet," says Urnov. "That said, now is not the time to feel false security, but rather added vigilance. "