Posts tagged ‘nobel prize’
McGill alumnus John O’Keefe was named co-winner of the 2014 Nobel Prize in medicine, for his contribution to the discovery of cells that constitute the brain’s ‘inner GPS,’ which makes it possible to orient ourselves in space.
O’Keefe, who received his doctorate in physiological psychology from McGill in 1967, is director of the Sainsbury Wellcome Centre in Neural Circuits and Behaviour at University College London. His co-winners of the Nobel Prize in Physiology or Medicine are May-Britt Moser and Edvard I. Moser, both based in scientific institutes in the Norwegian town of Trondheim.
“The discovery of the brain’s positioning system represents a paradigm shift in our understanding of how ensembles of specialized cells work together to execute higher cognitive functions. It has opened new avenues for understanding other cognitive processes, such as memory, thinking and planning,” the Nobel Prize organization said.
Fred Sanger, the only scientist to win the Nobel Prize for Chemistry twice, died yesterday at the age of 95. Dr. Sanger is perhaps best known by molecular biologists for the discovery of the Sanger method for sequencing DNA. Although modern day sequencing has seen many advances in the past decade, Sanger’s”dideoxy” chain-termination method for sequencing DNA was the method of choice used by scientists involved in sequencing the human genome.
We have embedded the video below as a tribute to Dr. Sanger. The video is an interview of Dr. Sanger conducted several years ago in which he discusses his personal background and his life’s work.
There’s the Nobel Prize and then there’s the Gairdner Awards. For Canada, the Gairdner Award is on par with the Nobel Prize in terms of it’s prestige among the scientific community. In fact, many Gairdner Award winners have gone on to win the Nobel Prize later on in thier career. That is why one Canadian scientist’s recent refusal to accept the Gairdner Award has been so controversial and so…Canadian.
Dr. Michael Houghton, a virologist at the Univerity of Alberta, was recently awarded the prestigious Gairdner Award for his work in identifying and cloning the hepatitis C virus. The discovery has proven extremely important for the world of medicine as it has reduced the risk of acquiring HCV through blood transfusion from one in three to about one in two million. In classic Canadian style, Dr. Houghton politely declined to accept the award since two of his colleagues were not similarly recognized.
To me, this is a gesture that all Canadians should be proud of. Wouldn’t you agree?
The Nobel Assembly at Karolinska Institutet has today decided to award The Nobel Prize in Physiology or Medicine 2012 jointly to John B. Gurdon and Shinya Yamanaka for the discovery that mature cells can be reprogrammed to become pluripotent
The Nobel Prize recognizes two scientists who discovered that mature, specialised cells can be reprogrammed to become immature cells capable of developing into all tissues of the body. Their findings have revolutionised our understanding of how cells and organisms develop.
John B. Gurdon discovered in 1962 that the specialisation 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.
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.
These groundbreaking discoveries have completely changed our view of the development and cellular specialisation. We now understand that the mature cell does not have to be confined forever to its specialised 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.
Life – a journey towards increasing specialisation
All of us developed from fertilized egg cells. During the first days after conception, the embryo consists of immature cells, each of which is capable of developing into all the cell types that form the adult organism. Such cells are called pluripotent stem cells. With further development of the embryo, these cells give rise to nerve cells, muscle cells, liver cells and all other cell types – each of them specialised to carry out a specific task in the adult body. This journey from immature to specialised cell was previously considered to be unidirectional. It was thought that the cell changes in such a way during maturation that it would no longer be possible for it to return to an immature, pluripotent stage.
Frogs jump backwards in development
John B. Gurdon challenged the dogma that the specialised cell is irreversibly committed to its fate. He hypothesised that its genome might still contain all the information needed to drive its development into all the different cell types of an organism. In 1962, he tested this hypothesis by replacing the cell nucleus of a frog’s egg cell with a nucleus from a mature, specialised cell derived from the intestine of a tadpole. The egg developed into a fully functional, cloned tadpole and subsequent repeats of the experiment yielded adult frogs. The nucleus of the mature cell had not lost its capacity to drive development to a fully functional organism.
Gurdon’s landmark discovery was initially met with scepticism but became accepted when it had been confirmed by other scientists. It initiated intense research and the technique was further developed, leading eventually to the cloning of mammals. Gurdon’s research taught us that the nucleus of a mature, specialized cell can be returned to an immature, pluripotent state. But his experiment involved the removal of cell nuclei with pipettes followed by their introduction into other cells. Would it ever be possible to turn an intact cell back into a pluripotent stem cell?
A roundtrip journey – mature cells return to a stem cell state
Shinya Yamanaka was able to answer this question in a scientific breakthrough more than 40 years after Gurdon´s discovery. His research concerned embryonal stem cells, i.e. pluripotent stem cells that are isolated from the embryo and cultured in the laboratory. Such stem cells were initially isolated from mice by Martin Evans (Nobel Prize 2007) and Yamanaka tried to find the genes that kept them immature. When several of these genes had been identified, he tested whether any of them could reprogram mature cells to become pluripotent stem cells.
Yamanaka and his co-workers introduced these genes, in different combinations, into mature cells from connective tissue, fibroblasts, and examined the results under the microscope. They finally found a combination that worked, and the recipe was surprisingly simple. By introducing four genes together, they could reprogram their fibroblasts into immature stem cells!
The resulting induced pluripotent stem cells (iPS cells) could develop into mature cell types such as fibroblasts, nerve cells and gut cells. The discovery that intact, mature cells could be reprogrammed into pluripotent stem cells was published in 2006 and was immediately considered a major breakthrough.
From surprising discovery to medical use
The discoveries of Gurdon and Yamanaka have shown that specialised cells can turn back the developmental clock under certain circumstances. Although their genome undergoes modifications during development, these modifications are not irreversible. We have obtained a new view of the development of cells and organisms.
Research during recent years has shown that iPS cells can give rise to all the different cell types of the body. These discoveries have also provided new tools for scientists around the world and led to remarkable progress in many areas of medicine. iPS cells can also be prepared from human cells.
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.
Sir John B. Gurdon was born in 1933 in Dippenhall, UK. He received his Doctorate from the University of Oxford in 1960 and was a postdoctoral fellow at California Institute of Technology. He joined Cambridge University, UK, in 1972 and has served as Professor of Cell Biology and Master of Magdalene College. Gurdon is currently at the Gurdon Institute in Cambridge.
Shinya Yamanaka was born in Osaka, Japan in 1962. He obtained his MD in 1987 at Kobe University and trained as an orthopaedic surgeon before switching to basic research. Yamanaka received his PhD at Osaka City University in 1993, after which he worked at the Gladstone Institutes in San Francisco, USA and Nara Institute of Science and Technology in Japan. Yamanaka is currently Professor at Kyoto University, where he directs its Center for iPS Research and Application. He is also a senior investigator at the Gladstone Institutes.
Gurdon, J.B. (1962). The developmental capacity of nuclei taken from intestinal epithelium cells of feeding tadpoles. Journal of Embryology and Experimental Morphology 10:622-640.
Takahashi, K., Yamanaka, S. (2006). Induction of pluripotent stem cells from mouse embryonic and adult fibroblast cultures by defined factors. Cell 126:663-676.
August 19, 2012 marked the 13 anniversary of the death of two time Nobel Prize recipient Linus Pauling. Pauling was one of the fathers of protein structure (he correctly proposed the alpha helix and beta sheet as the primary structural motifs in protein secondary structure) and antibody-antigen binding theory.
Below is a short video in his memory.
Happy 144th Birthday Marie Curie!
For scientists, the Nobel prize represents the greatest achievement of one’s lifetime. Most of us can only dream of becoming a Nobel prize winner and would be thrilled to even find ourselves in the presence of such aristocracy. Yet for one Canadian scientist, this year’s Nobel prize winner in physiology or medicine, the thrill of winning the Nobel prize will always be wrapped in tragedy.
On 3 October 2011, the Nobel Committee for Physiology or Medicine announced that Ralph M. Steinman had won the Nobel prize for his discovery of the dendritic cell and its role in adaptive immunity”. A prize which he was to share with colleagues Bruce Beutler and Jules A. Hoffmann. Unfortunately, Steinman was unable to claim his prize or even learn about the achievement of his lifetime as he had died three days earlier on September 30, 2011.
Below is an interview with Dr. Steinman after he won the The Royal Netherlands Academy of Arts and Sciences 2010 Dr A.H. Heineken Prize for Medicine.
May he rest in peace.