Rafu Shimpo, News Report, Posted: Oct 10, 2012

The Nobel Assembly at Karolinska Institutet on Oct. 8 decided to award the Nobel Prize in Physiology or Medicine 2012 jointly to John B. Gurdon and Shinya Yamanaka.

The two scientists discovered that mature, specialized cells can be reprogrammed to become immature cells capable of developing into all tissues of the body. Their findings have revolutionized our understanding of how cells and organisms develop.

Gurdon discovered in 1962 that the specialization of cells is reversible. 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.

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.

These groundbreaking discoveries have completely changed our view of cellular development and specialization. We now understand that the mature cell does not have to be confined forever to its specialized state. Textbooks have been rewritten and new research fields have been established. By reprogramming human cells, scientists have created new opportunities to study diseases and develop methods for diagnosis and therapy. Read more here.