Prime Editing, The future of Genetic Editing
Imagine a world without deadly genetic diseases, like cystic fibrosis, AIDS/HIV, and even cancer! That future is nearer than you think, in gene editing.
Genome Engineering (or just Gene Editing for short) is a new and disruptive technology with tremendous potential. Gene Editing works by modifying a person’s DNA.
DNA is sort of like the instructions about how to build a person. It contains everything about a person, from their eye colour, to how to replicate cells.
The problem is, DNA may also carry dangerous genetic diseases, such as down syndrome, Tourette’s, and (as mentioned before) cancer.
There are many tools and techniques for gene editing, all specializing in a particular field. Some tools rely on the body to make changes to the DNA and repair the tool’s damage, and others are more specific, inserting the changes into the DNA itself.
Prime Editing is a new gene-editing tool which so far has given promising results. Prime Editing is different from other gene-editing tools in a few ways.
As an example, let’s look at CRISPR-Cas9, one of the most popular gene-editing tools. CRISPR breaks the double helix in DNA, makes the modifications, and then relies on the body to heal the damage it caused. While this method works, it’s prone to fail due to a chance of the body’s healing process reverting changes done by CRISPR, causing unwanted side effects, which can be fatal in some cases.
This is where Prime Editing comes in. Instead of breaking open the double helix, Prime Editing can make small changes in the DNA without causing too much damage (See Figure A above). While this method is safer, Prime Editing can’t make the extensive changes CRISPR can make, limiting the possibilities that Prime Editing can do.
Just because Prime Editing can’t make the same substantial changes CRISPR-Cas9 can, doesn’t mean that it doesn’t have potential. There are still over 7,000 genetic diseases that prime editing can cure, including progeria and Tay-Sachs!
The main thing that sets Prime Editing apart from CRISPR and other tools is that it can change the DNA values.
DNA is scripted with four different types of nitrogenous bases (or just bases for short), adenine (A), cytosine (C), guanine (G) and thymine (T) (see Figure B above).
When these letters are strung together in a specific order, they define instructions to create different proteins, which can change almost anything about you from your hair colour to birthmarks to (of course) genetic diseases.
Prime Editing can pinpoint one base in the DNA and change it to another, compared to CRISPR-Cas9 replacing chunks of DNA. This method is safer and more effective.
Prime Editing is a massive step toward the future of genome editing, but there’s still so much more to come. Prime Editing is still undergoing extensive lab testing, but the results are promising and fascinating. As I mentioned before, prime editing will soon be used to treat diseases like progeria, Tay-Sachs, and other diseases that are caused by small genetic malfunctions.
