The Nobel Assembly at Karolinska Institutet on Monday decided to award the Nobel Prize in Physiology or Medicine 2012 to British researcher John B. Gurdon and Shinya Yamanaka of Japan for discovering that mature, specialised cells can be reprogrammed to become immature cells capable of developing into all tissues of the body.
"The Nobel Prize recognizes two scientists who discovered that mature, specialised cells can be reprogrammed to become immature cells capable of developing into all tissues of the body. Their findings have revolutionised our understanding of how cells and organisms develop," the Nobel Assembly at Karolinska Institutet said in a statement.
"These groundbreaking discoveries have completely changed our view of the development and cellular specialisation," it said.
"We now understand that the mature cell does not have to be confined forever to its specialised state. Textbooks have been rewritten and new research fields have been established.
"By reprogramming human cells, scientists have created new opportunities to study diseases and develop methods for diagnosis and therapy," read the statement.
"The discoveries of Gurdon and Yamanaka have shown that specialised cells can turn back the developmental clock under certain circumstances. Although their genome undergoes modifications during development, these modifications are not irreversible. We have obtained a new view of the development of cells and organisms," it said.
"Research during recent years has shown that iPS cells can give rise to all the different cell types of the body. These discoveries have also provided new tools for scientists around the world and led to remarkable progress in many areas of medicine. iPS cells can also be prepared from human cells," the statement said.
"For instance, skin cells can be obtained from patients with various diseases, reprogrammed, and examined in the laboratory to determine how they differ from cells of healthy individuals. Such cells constitute invaluable tools for understanding disease mechanisms and so provide new opportunities to develop medical therapies," it said.
Gurdon discovered in 1962 that the specialisation of cells is reversible.
In a classic experiment, he replaced the immature cell nucleus in an egg cell of a frog with the nucleus from a mature intestinal cell.
This modified egg cell developed into a normal tadpole. The DNA of the mature cell still had all the information needed to develop all cells in the frog.
Shinya Yamanaka discovered more than 40 years later, in 2006, how intact mature cells in mice could be reprogrammed to become immature stem cells.
"Surprisingly, by introducing only a few genes, he could reprogram mature cells to become pluripotent stem cells, i.e. immature cells that are able to develop into all types of cells in the body," read the Nobel statement.
Gurdon was born in 1933 in Dippenhall, UK. He received his Doctorate from the University of Oxford in 1960 and was a postdoctoral fellow at California Institute of Technology.
He joined Cambridge University, UK, in 1972 and has served as Professor of Cell Biology and Master of Magdalene College.
Gurdon is currently at the Gurdon Institute in Cambridge.
Yamanaka was born in Osaka, Japan in 1962. He obtained his MD in 1987 at Kobe University and trained as an orthopaedic surgeon before switching to basic research.
He received his PhD at Osaka City University in 1993, after which he worked at the Gladstone Institute in San Francisco and Nara Institute of Science and Technology in Japan.
Yamanaka is currently Professor at Kyoto University and also affiliated with the Gladstone Institute.