Stem Cell Scientists Win Nobel Prize in Medicine
October 8, 2012
Biologists John Gurdon of the Gurdon Institute in the United Kingdom and Shinya Yamanaka of Kyoto University in Japan won the 2012 Nobel Prize in physiology or medicine for their experimental findings on how adult animal cells can be transformed into stem cells. A stem cell is a cell that has the ability to develop into any of the different cell types that make up the tissues and organs of the body. This development process is called differentiation. Stem cells have the ability to divide endlessly, producing more stem cells or other types of cells.
In experiments with frogs conducted in the 1960’s, Gurdon demonstrated that the genetic material from a single cell of an adult frog contained all the information necessary to create a whole frog. He took the genetic material from the intestines of an adult frog and placed it inside an unfertilized frog egg. The resulting cell began to divide and developed into a tadpole as if it were a stem cell. Working independently in Japan, Shinya Yamanaka used a different approach to turn adult cells into stem cells. He altered individual genes in mouse skin cells to transform the cells into stem cells. These stem cells later differentiated into several different kinds of cells.
Being able to transform adult cells into stem cells could eliminate the need for controversial therapies that rely on embryonic stem cells. Scientists first succeeded in isolating (separating) and growing stem cells from a human embryo (developing human) in a laboratory in 1998. Such stem cells are called embryonic stem cells. These cells can differentiate into nerve, liver, muscle, blood, and all other cells that make up an organism.
This discovery led to a debate over whether it is morally acceptable to use cells taken from human embryos for research. The embryos are destroyed in the process of isolating the stem cells. Some people consider embryos as human beings with legal rights and believe it is wrong to destroy them. Other people believe that the potential medical benefits of embryonic stem cells justify their use. Learning how to control the creation and differentiation of stem cells will help scientists develop new treatments for many diseases, including Alzheimer’s disease, diabetes, and heart disease.
Additional World Book articles:
- Bone marrow transplant
- Genetic engineering
- Stem Cells: Seeds of Hope (a Special Report)
- Medicine (2007) (a Back in Time article)