Two scientists from different generations won the Nobel Prize in medicine on October 8 for the groundbreaking discovery that cells in the body can be reprogrammed to become completely different kinds, potentially opening the door to growing customized tissues for treatments.
The work of British researcher John Gurdon and Japanese scientist Shinya Yamanaka who was born the year Mr. Gurdon made his discovery has raised hopes of developing transplant tissue to treat diseases like Parkinson’s and Sir John Bertrand Gurdon (JBG), Fellow of Royal Society (born 2 October 1933) is a British developmental biologist. He is best known for his pioneering research in nuclear transplantation and cloning.
Prof Gurdon used a gut sample to clone frogs and Prof Yamanaka altered genes to reprogramme cells. The Nobel committee said they had "revolutionised" science. When a sperm fertilises an egg there is just one type of cell. It multiplies and some of the resulting cells become specialised to create all the tissues of the body including nerve and bone and skin. It had been though to be a one-way process - once a cell had become specialised it could not change its fate. In 1962, John Gurdon showed that the genetic information inside a cell taken from the intestines of a frog contained all the information need to create a whole new frog. He took the genetic information and placed it inside a frog egg. The resulting clone developed into a normal tadpole. The technique would eventually give rise to Dolly the sheep, the first cloned mammal.
Shinya Yamanaka, born September 4, 1962 in Higashiosaka) is a Japanese physician and adult stem cell researcher. He serves as the director of Center for iPS Cell Research and Application and a professor at the Institute for Frontier Medical Sciences at Kyoto University, as a senior investigator at the UCSF-affiliated J. David Gladstone Institutes in San Francisco, California, and as a professor of anatomy at University of California, San Francisco (UCSF). Dr. Yamanaka is also the current President of the International Society for Stem Cell Research (ISSCR).
Shinya Yamanaka used a different approach on stem cell research. Rather than transferring the genetic information into an egg, he reset it. He added four genes to skin cells which transformed them into stem cells, which in turn could become specialised cells. The Nobel committee said the discovery had "revolutionized our understanding of how cells and organisms develop. "The discoveries of Gurdon and Yamanaka have shown that specialized cells can turn back the developmental clock under certain circumstances.
Stem cells
Most adult cells in the body have a particular purpose which cannot be changed. For instance, a liver cell is developed to perform specific functions, and cannot be transformed to suddenly take on the role of a heart cell. Stem cells are different. They are still at an early stage of development, and retain the potential to turn into many different types of cell.
When a stem cell divides, each new cell has the potential to either remain a stem cell or become another type of cell with a more specialised function. Scientists believe it should be possible to harness this ability to turn stem cells into a super "repair kit" for the body. Theoretically, it should be possible to use stem cells to generate healthy tissue to replace that either damaged by trauma, or compromised by disease.
Among the
Scientists believe the most useful stem cells come from the tissue of embyros. This is because they are pluripotent - they have the ability to become virtually any type of cell within the body. Stem cells are also found within adult organs. They have not taken on a final role, and have the potential to become any of the major specialised cell types within that organ. Their role is to maintain the organ in a healthy state by repairing any damage it suffers. It is thought their potential to become other types of cell is more limited than that of embryonic stem cells. But there is evidence that they are still relatively "plastic".
Controversy
Campaigners are vehemently opposed to the use of embryonic stem cells. These cells are typically taken from lab-created embryos that are just four or five days old, and are little more than a microscopic ball of cells. However, opponents argue that all embryos, whether created in the lab or not, have the potential to go on to become a fully fledged human, and as such it is morally wrong to experiment on them. They strongly advocate the use of stem cells from adult tissue.
Some researchers fear that it is possible that stem cell therapy could unwittingly pass viruses and other disease causing agents to people who receive cell transplants. Some research has also raised the possibility that stem cells may turn cancerous. Work also still needs to be done to refine the new technique.
Recent winners of Nobel Prize in Medicine
2012- Briton’s John Gurdon and Japan’s Shinya Yamanaka for their discovery that mature cells can be reprogrammed into immature cells that can be turned into all tissues of the body, a finding that revolutionised understanding of how cells and organisms develop.
2011- American Bruce Beutler and French researcher Jules Hoffmann for their discoveries concerning the activation of innate immunity, sharing it with Canadian-born Ralph Steinman for his discovery of the dendritic cell and its role in adaptive immunity.
2010 - British researcher Robert Edwards for the development of in vitro fertilization.
2009 - Americans Elizabeth Blackburn, Carol Greider and Jack Szostak for their discovery of how chromosomes are protected by telomeres and the enzyme telomerase, research that has implications for cancer and aging research.
2008 - Harald zur Hausen and Francoise Barre-Sinoussi and Luc Montagnier for discoveries of human papilloma viruses causing cervical cancer and the discovery of human immunodeficiency virus.
2007- Mario R. Capecchi and Oliver Smithies of the United States and Martin J. Evans of the United Kingdom, for their discoveries leading to a powerful technique for manipulating mouse genes.
2006 - Andrew Z. Fire and Craig C. Mello of the United States for their work in controlling the flow of genetic information.
2005 - Barry J. Marshall and Robin Warren of Australia for their work in how the bacterium Helicobacter pylori plays a role in gastritis and peptic ulcer disease.
2004 - Richard Axel and Linda B. Buck, both of the United States, for their work in studying odorant receptors and the organisation of the olfactory system in human beings.
2003 - Paul C. Lauterbur, United States, and Sir Peter Mansfield, Britain , for discoveries in magnetic resonance imaging, a technique that reveals the brain and inner organs in breathtaking detail.
2002- Sydney Brenner and John E. Sulston, Britain, and H. Robert Horvitz, United States, for discoveries concerning how genes regulate organ development and a process of programmed cell death.
2001- Leland H. Hartwell, United States, R. Timothy Hunt and Sir Paul M. Nurse, Britain, for the discovery of key regulators of the process that lets cells divide, which is expected to lead to new cancer treatments.
2000 - Arvid Carlsson, Sweden, Paul Greengard and Eric R. Kandel, United States, for research on how brain cells transmit signals to each other, thus increasing understanding on how the brain functions and how neurological and psychiatric disorders may be treated better.
1999 - Guenter Blobel, United States, for protein research that shed new light on diseases, including cystic fibrosis and early development of kidney stones.
1998 - Robert F. Furchgott, Louis J. Ignarro and Ferid Murad, United States, for the discovery of properties of nitric oxide, a common air pollutant but also a lifesaver because of its capacity to dilate blood vessels
