John B. Gurdon transferred DNA between a tadpole and a frog to clone the first animal. Shinya Yamanaka used Gurdon’s concept to turn ordinary skin into potent stem cells. Both won the Nobel Prize for medicine today.
Gurdon, 79, a researcher at the University of Cambridge in the U.K., and Yamanaka, 50, a professor at Kyoto University in Japan, will share the 8 million-kronor ($1.2 million) prize, the Nobel Assembly said today in Stockholm. The pair’s findings have “created new opportunities to study diseases and develop methods for diagnosis and therapy,” the assembly said in a statement.
Gurdon’s feat, in 1962, paved the way in 1996 for the cloning of Dolly the sheep and, 10 years later, for Yamanaka, who turned mouse skin cells into stem cells with the potential to become any cell in the body. That achievement was lauded by some politicians and religious figures as a more ethical way to make stem cells because it doesn’t destroy human life.
“This field has had a long history, starting with John Gurdon,” Yamanaka, who was born the same year Gurdon published his achievement, said in an interview on the Nobel Assembly’s website. “I was able to initiate my project because of his experiments 50 years ago.”
Stem cells are found in human embryos and in some tissues and organs of adults, and have the potential to develop into different types of cells. That’s spurred scientists to look at ways of harnessing their power to treat diseases such as Alzheimer’s, stroke, diabetes and rheumatoid arthritis, according to the U.S. National Institutes of Health.
Gurdon showed that mature cells from specific parts of an animal’s body retain all the genetic information they had as immature stem cells. He took a cell from a tadpole’s gut, extracted the nucleus, and inserted it into the egg cell of an adult frog whose own nucleus had been removed. That reprogrammed egg cell developed into a tadpole with the genetic characteristics of the original tadpole, and subsequent trials yielded adult frogs.
Gurdon overturned the prevailing view that as cells differentiate, they lose genes and their ability to generate other cells of any kind, said Alan Colman, the executive director of the Singapore Stem Cell Consortium, who gained his doctorate under Gurdon at Cambridge.
“He’s amazingly passionate,” Colman said in an interview before the award was announced. “He was the sort of supervisor who you found it difficult to get appointments with, not because he was flying around the world, but because he was doing experiments all the time.”
Gurdon was answering e-mails in his laboratory when he received the call from Sweden today about the prize, he said in an interview on the Nobel Assembly’s website. His first reaction was, “It’s amazing if it’s really true,” he said. “Could it be that someone’s pulling your leg? That has happened before.”
Gurdon will celebrate at a reception that his institute is hosting today, and then he’ll be back to work early tomorrow, he said at a London news conference today.
Yamanaka’s breakthrough, first announced at a meeting in Toronto in 2006, stunned the scientific world by showing that even as cells of the body age, they retain in latent form the unlimited potential they had as embryonic cells. His feat was finding the genetic formula that reawakened that potential.
By adding four genes to a mouse skin cell, Yamanaka returned it to its immature state as a stem cell with the potential to become any cell in the body. He dubbed them induced pluripotent stem cells.
“When I first saw his results I was gobsmacked,” Colman said. “We all knew what he was doing but no one gave him the slightest chance of succeeding. It was remarkable and remains remarkable.”
Yamanaka’s achievement also sidestepped the ethical controversy surrounding human embryonic stem cell research, in which the cells are extracted from an embryo, which is destroyed in the process. A father of two daughters, Yamanaka began hunting for an alternative technique after a friend working at a fertility clinic showed him an embryo through a microscope.
“As I looked, I thought the differences are very small between these small cells, embryos, and my daughters,” he said in a 2009 interview. “I saw that if we could make pluripotent stem cells without using human embryos, that would be ideal. That’s the moment I thought about this project.”
Yamanaka, who said he was doing housework when the call from Stockholm came, started his career as an orthopedic surgeon and said he retains his desire to help patients.
“It turned out I’m not talented as a surgeon, so I decided to change my career from the clinic to the laboratory,” he said. “But I still feel I am a doctor. My goal, all my life, is to bring this stem-cell technology to bedsides, to patients, to clinics.”
Last year’s Nobel prize went to Jules A. Hoffmann, Bruce A. Beutler and Ralph M. Steinman for research illuminating how the body’s immune system recognizes infection and marshals an attack against it. Steinman died three days before the award was announced, without knowing he’d won it.
Annual prizes for achievements in physics, chemistry, medicine, peace and literature were established in the will of Alfred Nobel, the Swedish inventor of dynamite, who died in 1896. The Nobel Foundation was established in 1900 and the prizes were first handed out the following year.
An economics prize was created almost seven decades later in memory of Nobel by the Swedish central bank. Only the peace prize is awarded outside Sweden, by the five-member Norwegian Nobel Committee in Oslo.
The Nobel Prize in Physics will be announced tomorrow.