The Nobel Prize in physiology or medicine this year has been awarded to a British researcher named John Gurdon and a Japanese stem cell pioneer named Shinya Yamanaka. Both researchers showed that adult cells in our bodies have all the genes necessary to be reprogrammed into a more developmentally primitive state. Their discoveries, scientist hope, may be the basis for new treatments for diseases like Parkinson’s, diabetes and for studying the roots of diseases in the laboratory.
The Nobel prize committee at Stockholm’s Karolinska Institute said the discovery has “revolutionized our understanding of how cells and organisms develop.”
In 1962, John Gurdon showed that DNA from mature cells such an intestinal cells or skin cells could be used to generate new tadpoles. This revolutionary experiment definitely demonstrated that the genome of adult cells still possessed all the genes necessary to drive the formation of all cells of the body.
Ian Wilmut’s work at the Roslin Institute in Scotland that culminated in the cloning of Dolly the sheep utilized the same process that Gurdon had designed in frogs and showed that it could work in mammals.
Gurdon did his landmark experiment in 1962, the year the other Nobel prize winner, Shinya Yamanaka, was born. More than 40 years after Gurdon’s discovery (2006), Yamanaka used an incredibly simple yet elegant recipe to convert mature cells into primitive cells that could be differentiated into different kinds of mature cells.
These primitive cells, induced pluripotent stem cells or iPSCs were equivalent to embryonic stem cells. Embryonic stem cells, however, were embroiled in controversy, since derivation of embryonic stem cell lines required the destruction of human embryos. However, Yamanaka’s method provided a way to get such primitive cells without destroying embryos.
In the words of the Nobel committee: “The discoveries of Gurdon and Yamanaka have shown that specialized cells can turn back the developmental clock under certain circumstances. These discoveries have also provided new tools for scientists around the world and led to remarkable progress in many areas of medicine.”
As previously mentioned on this blog, Japanese scientists reported using Yamanaka’s approach to convert skin cells from mice into eggs that produced baby mice.
The 79-year-old Gurdon has served as a professor of cell biology at Cambridge University’s Magdalene College. Currently, he works at the Gurdon Institute in Cambridge, which he founded.
Yamanaka is 50 years old and previously worked at the Gladstone Institute in San Francisco and Nara Institute of Science and Technology in Japan. Currently, Yamanaka is at Kyoto University but retains his affiliation with the Gladstone Institute. Yamanaka is the first Japanese scientist to win the Nobel medicine award since 1987.
The work of Gurdon and Yamanaka earned them a Lasker award for basic research in 2009. Reprogramming cells has also been used in basic research in order to model certain genetic diseases in a culture dish. Cellular reprogramming allows scientists to create particular kinds of tissues with the exact abnormality they want to study. For example, scientists can make lung tissue afflicted with the mutations that cause cystic fibrosis, or brain tissue with Huntington’s disease. By reprogramming cells from patients that have a genetic disease, they can create new tissue with the same genetic flaws, and study it in the lab. Such a strategy can provide new insights into the roots of the problem.
In addition, that approach allows them to screen drugs in the lab for possible new medicines.
It is worth mentioning that Yamanaka’s motivation for developing iPSCs was a moral one. You see, he loved stem cell research, but did not want to destroy embryos. As told in a story published in the New York Times:
Inspiration can appear in unexpected places. Dr. Shinya Yamanaka found it while looking through a microscope at a friend’s fertility clinic. … [H]e looked down the microscope at one of the human embryos stored at the clinic. The glimpse changed his scientific career. “When I saw the embryo, I suddenly realized there was such a small difference between it and my daughters,” said Dr. Yamanaka. … “I thought, we can’t keep destroying embryos for our research. There must be another way.”
Dr. Yamanaka’s training taught him that there is no essential difference between a human embryo and a human adult. Differences in size, location, degree of dependence, and extent of development are not morally significant when it comes to the essential nature of an entity. The embryo is smaller than an adult, but so what? Are smaller people less human? Are the less developed less human? Or course not; they are less adult, but not less human. Does the degree of dependence determine your humanity? Then children and the aged are less human as are people after surgery. Surely this is absurd. Location? Now that’s even more ridiculous. There are the only differences between a human embryo and a human adult and they are purely accidental rather than essential differences.
It is amazing what a moral conviction can do. And note that Yamanaka is not a Christian. Therefore, you cannot say that he is a Christian fundamentalist pro-lifer. His is a purely scientific conclusion.
However, if I may opine on this – Why is human life valuable in the first place? It seems to me that people are valuable because they are a unique creation of God who loves them and values them. Therefore, they are inherently valuable and we should treat each life as precious. The conclusion that the embryo is not essentially different from a human adult is a scientific conclusion, but the conclusion that human life is valuable in the first place, is a religious conclusion.