GUARDIAN (UK), NOBEL COMMITTEE (Sweden)
STOCKHOLM - The 2012 Nobel Prize for Medicine was awarded to British and Japanese researchers who, decades apart, helped show that mature cells can be pluripotent, the Nobel committee announced Monday.
"John B. Gurdon discovered in 1962 that the specialization of cells is reversible," noted the press release announcing the winners. "In a classic experiment, he replaced the immature cell nucleus in an egg cell of a frog with the nucleus from a mature intestinal cell. This modified egg cell developed into a normal tadpole. The DNA of the mature cell still had all the information needed to develop all cells in the frog.
"Shinya Yamanaka discovered more than 40 years later, in 2006, how intact mature cells in mice could be reprogrammed to become immature stem cells. Surprisingly, by introducing only a few genes, he could reprogram mature cells to become pluripotent stem cells, i.e. immature cells that are able to develop into all types of cells in the body."
The Guardian provided some background on Yamanaka's breakthrough: "In 2007, Shinya Yamanaka at Kyoto University in Japan demonstrated a way of producing ES-like cells without using eggs. He took a skin cell and, using a virus, inserted four specific bits of DNA into the skin cell's nucleus. The skin cell incorporated the genetic material and was regressed into an ES-like cell – it had been "reprogrammed" using a batch of chemicals in the lab. In a few short experiments, scientists had a near-limitless supply of stem cells that were, seemingly, as good as ES cells for their research..."