Vol.9, March 2017
Erika Sasaki Ph.D.
Central Institute for Experimental Animals
Department of Applied Developmental Biology
Advanced Research Center, Keio University
Background to research
Before humans can take new drugs or medical treatments, we first check their safety with animal experiments.
These tests are usually done with mice but when we do not know the safety with mice then we use primate experiments. Amongst these we use small monkeys called common marmosets.
In particular, we are developing the world’s first transgenic and gene knockout marmoset sets.
Internationally acclaimed findings
In 2009 we reported in Nature the development of technology to produce transgenic marmosets where the genes from a transgenic marmoset were passed onto its children's generation.
I thought that these were important and impressive results the moment I learned that they could be used to develop drugs and therapies by making diseases models of people using primates.
Applications of the research
I think it would be great to not only produce models to cure diseases such as Parkinson's and Alzheimer's, but also to apply our research to delay their onset.
Actually, many mice models have been made for Parkinson’s disease by genetic modification. But mice have not been produced in which the progress and symptoms of diseases can be reproduced.
Other groups have tried to produce monkeys as models for Parkinson's disease but they were only able to reproduce one part of the disease in humans. Producing transgenic Parkinson's model enabling modeling from onset and other stages in its progression. I think it may be possible to produce drugs to control the progression.
Sources of ideas for research
Since my time as a student I had conducted research on producing transgenic chickens to solve problems of food shortage. But consumers did not want to eat genetically modified food and this area of research shrank considerably.
I think that transgenic technology is very important for fundamental research on embryology. Technology for mice is well established but it was used more for gene analysis than basic research. It was when I was thinking about other possible research directions, when I came across the idea for the marmoset.
The main reason that this research has been successful here at the Central Institute for Experimental Animals is that the marmoset breeding technology is the best in the world and we can use as many as required without excess or deficiency. Also, at that time, the members of the research team worked very hard with great enthusiasm.
Contribution to society
We can make wide ranging disease models to test the effectiveness and safety of drugs for humans with minimal side effects. But producing animal models consists of routine work for which I assembled a transgenic marmoset business team last October.
I think that this team can work with many kinds of pharmaceutical companies.
For me, as a researcher, I want to resolve the bottleneck:
Although they have high reproductive power, the marmoset's growth is slow. So even though they are good models, many people cannot use them.
I want to resolve the bottleneck of the marmoset with long life cycle,
How to breakthrough the bottleneck
One solution is to make germ cells from ES and iPS cells and produce the next generation by in vitro insemination.
For example, if a transgenic marmoset is born, then the next day, we can take some of its blood or skin, make iPS cells, and sperm and eggs, then the days after Its birth, we can start the job of breeding the next generation of marmoset.
Another solution is slightly more technical, in mice, ES cells can be transplanted into fertilized eggs of other bodies to create chimeric mice. But because this can only be done with mice and rats, and hepatocytes researchers are trying to explain why. I want to resolve this, and make cells to produce chimeric cells from ES and iPS cells.
Another approach is somatic cell nuclear transfer. By doing this, as well as speeding up alternations of generations, we could also produce animals with the uniform genetic backgrounds. In the future I want to pursue these aspects of my research.
What to expect to KING SKYFRONT
The close proximity of Haneda Airport enables easy access for people from both Japan and overseas.
We conduct research using monkeys. In reality, it is very difficult to import or export even as single drop of blood sample. So, instead, it is much faster if people fly in and we do the experiments here. This would make Central Institute for Experimental Animals and KINGSKYFRONT the global center for marmoset research.
Also, KINGSKYFRONT has research institutes with expertise in many different areas. I think that we should put more effort into medical engineering collaboration.