This morning the Nobel committee announced that Drs. John B. Gurdon and Shinya Yamanaka have jointly won the Nobel Prize in Physiology or Medicine for their work on induced pluripotent stem (iPS) cells. Surprisingly, the seminal work for which these two researchers received the award was done over 40 years apart!
In 1962, Dr. John B. Gurdon published a study showing that the nucleus of a frog's egg could be replaced with the nucleus from a mature intestine cell, and the egg would still develop into a fully functional normal tadpole. Later work, showed the tadpoles grew to fully functioning frogs. The cell's nucleus contains the majority of the DNA, so the experiment proved that all the genetic information to program development of a whole organism is contained in each cell. This was the first example of cloning and similar to the technique used to clone the first mammal, a sheep named Dolly, over 30 years later.
In 2006, almost 45 years after Dr. Gurdon's frog cloning, Dr. Shinya Yamanaka pushed the idea that each cell had the genetic capability to become any type of cell one step further. He figured out how to actually reprogram a body cell into an embryo-like stem cell. Yamanaka's group found that just 3-4 genes are required to de-differentiate mouse skin cells into stem cells, and that these reprogrammed cells could then transform into other types of body cells. Essentially, they reversed differentiation and made stem cells from body cells. These are iPS cells.
Two new studies just a couple months ago have brought the research full circle to fully bridge Dr. Yamanaka's work with Dr. Gurdon's. Research groups at the Institute of Zoology in Beijing and Fanyi Zeng of Shanghai Jiao Tong University found that they could substitute iPS cells made using the Yamanaka protocol for early stage embryonic stem cells to create baby mice derived entirely from the reprogrammed iPS cells.
In granting the award, the Nobel Assembly noted that, "Research during recent years has shown that iPS cells can give rise to all the different cell types of the body....and led to remarkable progress in many areas of medicine. 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."
For more background on Stem cells, take a look at, The Range of Stem Cell Technology, and Stem Cell Therapies. Also, check out the overview of a discussion with leading stem cell researchers, including Shinya Yamanaka, in Experts Assess the Current Status of Stem Cell Research.