Two discoveries over the course of more than 40 years are now getting credit for revolutionizing the way scientists look at saving and creating life.
The Nobel Prize committee Monday awarded the Nobel Prize in Medicine to Britain's John Gurdon and Japan's Shinya Yamanaka for those discoveries in their work with cells, often called the building blocks of life.
First Gurdon and then Yamanaka showed that mature, specialized cells could be reprogrammed, causing them to revert to an immature, embryonic state and then turned into a different type of specialized cell.
The implications are enormous, allowing researchers to work on technology that could one day allow doctors to fight disease by regrowing tissue in damaged brains, hearts or other organs.
"This year's Nobel Prize awards a discovery that has changed the way we understand how cells in the body become specialized," said Thomas Perlmann, Professor of Molecular Development Biology of the Karolinska Institute in Sweden. "It has provided entirely new tools for effective development of drugs and new therapies."
Until recently, many scientists thought the only viable way to do this was to use embryonic human stem cells, which involved the destruction of a human embryo. The discoveries also set the stage for work on advanced cloning techniques and other technologies involved in creating life itself.
"This brings me great joy, but at the same time I feel a great sense of responsibility," said Yamanaka, now at Japan's Kyoto University. "Stem cell research is still a very new field.''
Gurdon's work in 1962 was the first, critical step in demonstrating the process of cell specialization was not set in stone, as long thought.
Using frogs, Gurdon took the immature nucleus out of an egg cell and replaced it with the nucleus from a cell taken from a frog's intestine. Despite the switch, the modified egg cell still developed into a normal tadpole.
The discovery showed that even mature, specialized cells had all the information required to change, first into stem cells and then into numerous different types of cells.
At the time, not even Gurdon, now at the Gurdon Institute in Cambridge in Britain, realized how important the discovery would be.
"This work I was involved in had no obvious therapeutic benefit at all," he said. "It was kind of purely a scientific question: Do all our cells have the same genes? There was no prospect of that being useful to people."
It was a theoretical breakthrough, but just what exactly allowed specialized cells to transform remained a mystery.
Unlocking the key
The question lingered for more than 40 years. Then, in 2006, Shinya Yamanaka uncovered the mechanism, tracing the transformation to four specific genes.
Yamanaka took skin cells from adult mice and found by simply introducing a combination of four genes, he and his colleagues could essentially turn back time, transforming a mature, adult skin cell into a stem cell like state.
"The reality is that both medicine and drug research has such great potential," he said. "We have not even really begun to explore all the possibilities in medical and pharmaceutical development."