Scientists are improving gene editing with a process known as Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR). This technique cuts open deoxyribonucleic acid (DNA) molecules at specific locations, giving it the potential for curing genetic diseases. CRISPR gene editing has accelerated medical research over the last decade by allowing scientists to repair DNA in cells. A team of researchers at Case Western Reserve University is using chemical processes to further improve the location and timing of CRISPR. The results of this technique were first published in a 2022 issue of Nature Communications.
The precision of CRISPR directly affects its effectiveness and adverse side effects, making it essential to continue developing this research. Fu-Sen Liang, leader of the research team, stated the work is still preliminary, but it could lead to more effective treatment for some forms of cancer. The latest technique uses a chemical to target ribonucleic acid (RNA), allowing scientists to change the gene’s expression at a particular time. It also allows them to stop this process at a specific stage.
CRISPR is a transformative technology initially developed in 2012. It uses RNA to guide the action of a particular enzyme in targeting, cutting and repairing damaged DNA strands. It inserts new DNA material into the strands, thus changing the gene and the physical characteristics it produces. The scientists at Case Western Reserve have focused on manipulating RNA to achieve multiple functions such as regulating gene activity and translating genetic information. They can also modify RNA molecules with the same genetic sequences through various chemical means to obtain different properties.
CRISPR is the most versatile genetic manipulation currently available, providing it with a wide range of possible applications. Researchers primarily use it to perform short insertions or deletions at a specific site, but they also use CRISPR to make large DNA deletions around a targeted site. However, these types of deletions may have a lower editing efficiency. The primary limitation of traditional CRISPR is that it lacks the temporal control needed to understand the dynamic process of RNA modifications and their effects. The crux of Liang’s research has been to develop methods of improving this control to the point that CRISPR is a useful research technique.
In particular, Liang’s team used abscisic acid (ABA), a common plant hormone, to perform chemically induced proximity (CIP). This technique allowed the researchers to precisely time a host of biologic processes such as chromatin regulation, degradation, localization, protein folding, signaling cascades and transcription. They further increased the precision of the CRISPR gene editing process by using ultraviolet (UV) light to activate the ABA at the desired time.
These capabilities allowed Liang’s team to write and erase a feature called N6-methyladenosine (m6A) on a specific area of the RNA. This feature is significant because scientists believe it regulates fundamental RNA processes and properties, including RNA-protein interaction. While scientists have discovered other types of RNA modifications like N1-methyladenosine (m1A), 5-methylcytosine (m5C), N7-methylguanosine (m7G) and pseudouridine (Ψ), m6A is the most prevalent in eukaryotic cells. As a result, defects in m6A are the cause of many genetic diseases.
The combination of the chemical process with CRISPR provides scientists with precise control over the timing and location of changes to m6A. As a result, they can effectively switch between two versions of RNA. This capability is proving crucial for learning about the roles these RNA versions play in biological processes and diseases. Liang believes this research can be applied to other RNA modifications besides m6A, which opens the door for making a virtually unlimited number of genetic changes.