Column

Column

How the important people view?

Promotion of research from a broad perspective to take a next step forward (2) -All 3 episodes-

Prof. Makoto Asashima

image Prof. Makoto Asashima

Interviewer :
In Japan, are there not many research projects on ES cells and other stem cells any more?

Asashima :
Unfortunately, there are only two research projects authorized for the generation of human ES cells : one is led by Prof. Nakatsuji (Institute for Integrated Cell-Material Sciences, Kyoto University) and the other is led by Prof. Umezawa (Department of Reproductive Biology and Pathology, National Research Institute for Child Health and Development). On the other hand, the conditions were made less strict last year for the use of human ES cells, and there are now many institutions where human ES cells are used. At our university (The University of Tokyo) also, there are research projects using these cells. In Japan, there have been many research projects using mesenchymal stem cells for studying undifferentiated and dedifferentiated states of cells. And there have been many projects using hematopoetic stem cells mainly for studying their transplantation. In recent years, however, it is difficult to obtain research funding if your research subject is not on iPS cells, and some researchers do not even bother to apply.
iPS cells are indeed a great achievement.And it is important to go with researchers in neighboring areas including research on other stem cells, development and differentiation, if we think about the future development of iPS cell research, especially of Japan.

In USA, while George Bush, Former President of the United States, imposed a ban on federal funding for human ES cell research, Harvard University, the Massachusetts Institute of Technology (MIT), and the University of California worked together to obtain private funds and invite a wide variety of competent researchers to the field of ES cell research, to accumulate research findings.On these grounds the pace of iPS cell research has been accelerating since its advent. This is a good example to illustrate that scientific research institutions are required to develop their plans based on a flexible long-term vision. Japan should have built grounds for iPS cell research earlier.

Interviewer :
We can see, even from the website of the University of Wisconsin, that they have layers of basic research built on the basis of ES cell research.This is a situation different from that in Japan where only iPS cell research is prominent.

Asashima :
Young Japanese researchers understand what are iPS cells, but do not have knowledge accumulated in ES cell research.
There are many ES cell lines, among which different cell lines give different cell reactivity and pluripotency.Young researchers have to understand these differences.It is important to obtain basic data that allow them to understand differences in cell characteristics between different cell lines.And the reproducibility of the data is important.In order that iPS cell research takes a next step, it is essential that they have basic understanding of what the cell is.Understanding iPS cells without knowledge of ES and other stem cells is not realistic.

For iPS cells, while we do not have to care about the problem of immune rejection and ethical issues, we do not have yet understood the mechanisms of dedifferentiation of differentiated fibroblasts, and have many things to be solved, for example, the maintenance of reprogrammed cells and the control of differentiation into desired cells in a safe manner.
Also in Japan, somatic stem cells, including adipose and bone marrow stem cells, have been studied. If we want to use these stem cells for treatment of patients with certain diseases, we collect these stem cells (undifferentiated cells) from the same patients, and in this case we have neither risk of immune rejection nor ethical problems. And we can obtain a large number of adipose stem cells.
The question is how to differentiate them. Scientists in other countries have also noted the importance of this question and are trying to answer it. In USA, they have already launched research projects for regenerating spinal cord and retina from ES cells, and other projects for other tissues.

Dynamic nature of life

Prof. Makoto Asashima

Interviewer :
There are many things to be explained. Do you have any comment on this point from the viewpoint of developmental biology?

Asashima :
The fertilized egg has a fixed program of development according to which it differentiates into different tissues.The iPS cell is a cell reprogrammed from a differentiated state.

When we cut off a forefoot of a newt, the animal dedifferentiates its blood vessels, bones, and muscles to regenerate them. Lizards and planarian do the same thing.
Humans have lost much of their regenerative function. However, if two thirds of the liver is lost, the remaining one third will dedifferentiates to regenerate; the liver turns from red to white during this process of dedifferentiation.This is also the case of the bone marrow. Eighty million blood cells are destroyed and regenerated every second. A cut on the skin is a good example. Transparent pus from the wound contains undifferentiated stem cells. Owing to such a regenerative ability, humans can maintain homeostasis.

We have good mechanisms.
We do not have a regenerative ability as high as that of the newt, and it is important to learn from such an animal.We have stem cells in our brain, eyes, hepatocytes, heart, and muscles, and they help each organ maintain homeostasis. Activation of the function of stem cells that are present in the human body may also be considered as a form of regenerative medicine.
It is said that the number of brain cells will not increase any more, if a person turns twenty. However, recent studies have revealed that the hippocampus contains a lot of stem cells. The activation and subsequent differentiation of these stem cells may lead to treatments of Alzheimer's and other diseases.

The system of the human body is very complex, and sometimes there are more than one path to obtain a certain result.
iPS cells are not "almighty", and to find a way to use them in harmony with the natural laws is important.We have to consider the whole of the necessary studies here as a life science. What is a normal cell? What will happen if its homeostasis is disequilibrated? We have to make comprehensive studies to answer all these questions.


Interviewed by Miwako Honma (supervisor of iPS Trend website), Katsuaki Sato,Yuki Konagaya(Japan Science Technology Agency)
Published on 5 February, 2010

  1. 1
  2. 2
  3. 3

Prof. Makoto Asashima

Professor Emeritus, Former Vice President, member of the Board of Directors, and Research Professor of the University of Tokyo
Senior Research Fellow of the Center for Research and Development Strategy, Japan Science and Technology Agency
Chief of Organ Development Research Laboratory, the National Institute of Advanced Industrial Science and Technology

1972 : Graduated from the Doctoral Course of the School of Science, the University of Tokyo (Received a doctorate in science)
Researcher at Institut fur Chemie und Biochemie, Freie Universitat Berlin Associate Professor and Professor at the Faculty of Liberal Arts, Yokohama City University
1993 : Professor at the Graduate School of Arts and Sciences, the University of Tokyo
1996 : Professor at the Department of Language and Information Sciences, the Graduate School of Arts and Sciences, the University of Tokyo
2003 : Director of the Department of Language and Information Sciences/Director of the Graduate School of Arts and Sciences, the University of Tokyo
2005 : Vice President of the Science Council of Japan
From 2007 to March 2008 : President and Vice Principal of the University of Tokyo

President of the Japanese Society of Developmental Biologists
President of the Zoological Society of Japan
President of the Molecular Biology Society of Japan
President of the Japanese Society for Biological Sciences in Space
Steering Committee and Council Member of the Japan Society for Cell Biology
Steering Committee Member of the International Society of Developmental Biologists
Board Member of the Japanese Society for Tissue Engineering
Board Member of the Japanese Society for Regenerative Medicine
Board Member of the Japanese Society of Inflammation and Regeneration
Member of the New York Academy of Sciences
Editorial Board Member of journals : "Development, Growth & Differentiation", "Zoological Science", and "Cell Structure and Function"
Vice Editorial Chief of the "International Journal of Developmental Biology"

He specializes in developmental biology, and has been and is working on organogenesis (from an egg to larva), cell growth and differentiation. He identified activin, a mesoderm-inducing factor, in 1988 for the first time in the world, and contributed to establishing a system of inducing organs.

Awards :
1990 : The Prize of the Zoological Society of Japan
1990 : Inoue Prize for Science
1990 : Man of the Year (USA, ABI)
1994 : Kihara Memorial Yokohama Foundation for the Advancement of Life Sciences
1994 : Philipp Franz von Siebold-Preis (German Government)
1999 : Toray Science and Technology Prize
2000 : Academic Award for Medical and Pharmaceutical Research of the Mochida Memorial Foundation
2000 : The Naito Foundation Merit Award for Advancement of Science
2000 : Professor Kei Arima Memorial Award of the Japan Bioindustry Association
2001 : Uehara Prize
2001 : The Medal with Purple Ribbon
2001 : Imperial Award of the Japan Academy
2002 : The Medal of the Prince Hitachi Prize for Comparative Oncology
2008 : Erwin-Stein-Preis
2008 : Person of Cultural Merit

Movie

See more

Page top

Movie

Movie

  • MEXT
  • Japan Science and Technology Agency
Page top