Nobel Prize goes to pioneers of induced stem cell research
LOS ANGELES (MCT) — John Gurdon and Shinya Yamanaka were jointly awarded the Nobel Prize in Physiology or Medicine on Monday for their research on resetting cells to their earliest developmental stages. The work has yet to yield a clear breakthrough in medical treatment, but it has revolutionized scientists’ ability to study both normal and diseased development.
Gurdon, 79, performed his seminal work in the late 1950s and early 1960s – a good deal of it before Yamanaka was born. In his most famous study, Gurdon showed that replacing the nucleus of an adult cell with the nucleus of an embryonic cell reset the adult cell to an embryonic state: Many of the cells became tadpoles. This strongly suggested that embryonic-state DNA and the molecules that controlled gene expression in the nucleus were sufficient to make a cell “pluripotent” again – or capable of turning into any type of tissue in the body.
Some 40 years later, Yamanaka took this further by showing that adult mouse skin cells could be reset to their embryonic state just by adding a set of genes into the cells’ nuclei, and he later reduced this number to just four genes. The cells are now referred to as induced pluripotent stem cells, or iPS cells, and are a common tool in the study of development and disease.
With Yamanaka’s discovery, researchers suddenly had a way of studying pluripotent stem cells without destroying embryos – a limitation that had caused countless headaches at the time of Yamanaka’s breakthrough, as President George W. Bush had instituted severe limitations on such research.
Since Yamanaka’s seminal finding, researchers have used the approach to demonstrate some stunning feats: They have turned the skin cells of people who have Parkinson’s disease into “disease in a dish” models that allow them to watch the development of the disease over time and to observe what genes go wrong when and why, and, just last week, a team of scientists published research that used the approach to turn mouse skin cells back into mouse eggs, which then produced baby mice.
The technique has not been without complications: Because one of the four genes is also highly implicated in cancer, the iPS cells are more likely to become cancerous than true embryonic stem cells. The issue has slowed research in the field.
Today, Gurdon works at the Gurdon Institute in Cambridge, England, which he founded, and Yamanaka has appointments at UC San Francisco’s Gladstone Institute and at Kyoto University.