Lab’s Door
Expanded targeting space of genome editing
Osamu Nureki, Professor, Dept. of Biological Sciences
"Abstract of our research"
 
CRISPR-Cas9 is an enzyme that is induced by RNA, binds to a specific DNA, cleaves double-stranded DNA targets.
It can not cleaves target DNA without PAM.
PAM is lined with guanines, but it is hardly appear in the genome.
As a result, places where genome editing was possible were limited.
In this research, we made Cas9 which makes it easy to target various places.
"Significance of our research"
 
"Off-target" is a major problem in genome editing.
In other words, this is to cut off unwanted parts, which also causes cancer.
One of the first research results of this time is that freely designing guide RNA can reduce the frequency of off-target occurrence.
Next, as a recent problem, even if cutting the correct position, there are cases where large mutation occurs in some cases.
However, it has been found that such problems do not occur if the design of the guide RNA is proper.
It is possible that we design to avoid such dangers with our tools.
In addition, treatment that does not perform cleaves in genome editing is also in the limelight.
This is a method in which Cas9 carries out base substitution of the genome and treats the mutation.
Also in this case there are parts that can not be base substitution due to strict limitations of PAM.
If the PAM sequence is free, more diseases can be treated.
In brief, our research has these three advantages.
1. Not cut unnecessary parts
2. Be able to design Guide RNA avoiding danger
3. It is possible to cure diseases without cutting DNA3
"Future prospects"
 
We aim to apply genomic editing to medical treatment.
I would like to focus on treating genetic diseases and other diseases.
For that purpose, I would like to take advantage of Cas9, which can avoid various risks.
Currently, the mainstream of treatment methods is a method of taking blood cells outside of the body and treating them.
In the future, I would also like to use methods of genome treatment in the body.
For that, "super cas9" which is smaller in size and is free to genome edit is necessary.
This is near completion.
We want to challenge treatment of various diseases.
Expanded targeting space of genome editing
For more details, check UTokyo science's website.
