New CRISPR tool could enable gene editing over time, study shows

Researchers have discovered a new CRISPR gene-editing technique that allows for the programming of sequential cuts over time. The study was conducted at the University of Illinois Chicago (UIC), US. 

“A drawback of currently available CRISPR-based editing systems is that all the edits or cuts are made all at once. There is no way to guide them so that they take place in a sequential fashion, one after the other,” said UIC’s Associate Professor Bradley Merrill, lead author of the paper.

The researcher’s new process involves the use of special molecules called guide RNA that ferry the Cas9 enzyme within the cell and determine the precise DNA sequence at which Cas9 will cut. They call their specially engineered guide RNA molecules “proGuides”. According to the team, these molecules allow for the programmed sequential editing of DNA using Cas9.

While proGuide is still in the prototype phase, Merrill and colleagues plan to further develop their concept and hope that researchers will be able to use the technique soon.

“The ability to preprogramme the sequential activation of Cas9 at multiple sites introduces a new tool for biological research and genetic engineering,” Merrill said. “The time factor is a critical component of human development and also disease progression, but current methods to genetically investigate these processes do not work effectively with the time element. Our system allows for gene editing in a pre-programmed fashion, enabling researchers to better investigate time-sensitive processes like how cancer develops from a few gene mutations and how the order in which those mutations occur may affect the disease.”

The findings on CRISPR are published in the journal Molecular Cell.