CRISPR, CRISPR, CRISPR. We've all heard about it's gene editing capability, but it has potential to do so much more - controlling genes and offering a precise delivery system.
More than an editing platform
The CRISPR-Cas9 system does a wonderful job, partly because it targets genes so specifically. It's not the only system that does this, but it's the cheapest and easiest to create so far. For those with imagination however, this targeting quality means it could do so much more than simply snip away at sequences. Targeting promoter sequences, delivering a payload to a specific region of DNA...the platform has enormous potential.
Blunting the scissors
The CRISPR-Cas9 system consists of the guiding element CRISPR, combined with the snipping enzyme Cas9. If you could blunt these scissors but keep the guiding system, then it could be modified for another use. That's exactly what scientists at Stanford University have now done.
By blunting Cas9, the system becomes an excellent delivery platform. You can attach molecules that affect gene expression - turning genes on and off, or even make markers for finding a gene. Essentially, you can deliver anything related to gene expression and control; silencing, activating and altering the way your DNA works.
Why is this so exciting?
Because genes are so much more than their sequence alone. Expression and control is a huge part of what makes you, you. If we discover some versions of genes are helpful or nasty for example, we could use the system to piggyback molecules that change its expression. Some mutations produce harmful variants of a gene, but by silencing it altogether you stop this happening. The potential also stretches to fighting disease, silencing cancer promoting genes or altering the composition of your immune system to clear away a pathogen.
“We immediately thought: Well, let’s just break the scissors”
The potential of this system was clear from the beginning, and research has kept pace with the excitement. Two systems have already been created called CRISPRi which interferes with gene activity and CRISPRa, which activates it. Gene expression is also more than silencing and activation; it can be specifically tuned within a range for optimum activity.
“I hope that the dead-Cas9 platform can one day partially replace the drugs that people have developed for treating cancers or other diseases. It’s equivalent to using a cocktail of drugs, but with much better specificity”
The system can also target and affect gene expression controlling cell fate - providing a potent method of creating new stem cells, or changing a cell into another.
Like any technology there are many hurdles to overcome before this is a reality. In order to affect gene expression, you need whatever is doing it to remain there for a while which could trigger an immune response. Delivering the CRISPR system is already a challenge, let alone if you wanted to deliver it multiple times. Nevertheless, if these challenges can be overcome the potential is only limited by imagination (and money).
“If we can get it to work, it’s fundamentally safer and better than cutting your DNA”
Read more at The Atlantic