This year’s Nobel Prize for Physiology or Medicine went to two stem cell pioneers: Shinya Yamanaka and John Gurdon. The two scientists showed that mature cells such as those of the skin or intestine can be coaxed back to an embryonic-like state and can then form all tissues of the body.
According to the Nobel Prize announcement:
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.
Shinya Yamanaka has a co-appointment at the CIRM-funded Gladstone Institutes in San Francisco (here’s a list of all CIRM awards to Gladstone scientists). Their press release discusses the importance of Yamanaka’s work in the development of new therapies:
Six years ago, Dr. Yamanaka discovered that by adding just four genes into adult skin cells in mice, he could induce the cells to become like embryonic stem cells. He called them induced pluripotent stem cells, or iPS cells. In 2007, he announced that he had done the same with human adult skin cells.
Embryonic stem cells—which are “pluripotent” because they can develop into any type of cell—hold tremendous promise for regenerative medicine, in which damaged organs and tissues can be replaced or repaired. Many in the science community consider the use of stem cells to be key to the future treatment and eradication of a number of diseases, such as diabetes, blindness and Parkinson’s disease.
Gurdon, who shared the award, carried out classic experiments in the 1960s showing that the nucleus from an adult intestinal cell could be placed into an egg, which then formed a normal tadpole. Together, the two sets of experiments overturned conventional wisdom, which held that once a cell matured into an adult type such as skin or intestine it lost the ability to form any other tissues.
CIRM president Alan Trounson said:
“There are few moments in science that are undisputed as genuine elegant creativity and simplicity. Shinya Yamanaka is responsible for one of those. The induced pluripotent stem cells he created will allow us to interrogate and understand the full extent and variation of human disease, will enable us to develop new medicines and will forever change the way science and medicine will be conducted for the benefit of mankind. An extraordinary accomplishment by a genuinely modest and brilliant scientist. He absolutely deserves a Nobel award.”
Before Yamanaka’s 2007 announcement that he had reprogrammed adult skin cells to an embryonic state most stem cell research focused on embryonic stem cells or tissue-specific stem cells. Just five years later, CIRM alone is funding almost $190 million in awards developing better ways of creating iPS cells and using those cells to develop new therapies (the full list of iPS grants is on our website).
One CIRM disease team is attempting to use iPS cells to develop a therapy for the devastating childhood skin condition epidermolysis bullosa (here’s a link to that award). Those scientists hope to be in clinical trials in the next few years.
Since Yamanaka’s discovery there has been public debate about whether the reprogrammed iPS cells rendered embryonic stem cells unnecessary. The idea was that both cells had the potential to form all cells in the body and could therefore be used in similar ways to develop therapies.
In fact, many experiments have shown some differences between the two cell types. CIRM funds research with all types of stem cells – adult, iPS and embryonic – because until it’s clear which cell type is best suited for each type of therapy we don’t want to limit the options for getting those therapies to patients.
You can read more about iPS cells in previous blog entries:
- The confusing (and ongoing) story of iPS vs. embryonic stem cells
- The right tool for the job: is it iPS, ES or adult? Answer: It depends