Two Scientists from Britain and Japan shared the Nobel Prize last Monday for the discovery that adult cells can be transformed back into embryo-like stem cells that may one day regrow tissue in damaged brains, hearts or other organs.
Sir John Gurdon, 79yrs (Gurdon Institute in Cambridge,Britain) and Shinya Yamanaka, 50yrs (Kyoto University in Japan), managed to discover ways to create tissue that would act like embryonic cells, without the need to collect these cells from embryos.
They will be sharing the $1.2 million Nobel Prize for Medicine, for work that Gurdon began 50 years ago and then Yamanaka capped with a 2006 experiment that transformed the field of “regenerative medicine” – the search for ways to cure disease by growing healthy tissue.
“These groundbreaking discoveries have completely changed our view of the development and specialization of cells,” the Nobel Assembly at Stockholm’s Karolinska Institute said.
Every part in the body starts off as stem cells, before transforming into organs and tissues like skin, blood, nerves, muscle and bone. The main idea is that stem cells can grow to replace damaged tissue in cases from spinal cord injuries to Parkinson’s disease as well as have application in other parts of medicine.
Scientists once thought it was impossible to turn adult tissue back into stem cells, since in the development to a “mature” cell, many hormones, growth factors etc. have an impact, something that can not be easily controlled or manipulated. That meant new stem cells could only be created by taking them from embryos, which raised ethical objections that led to research bans in some countries.
As far back as 1962, Gurdon became the first scientist to clone an animal, making a healthy tadpole from the egg of a frog with DNA from another tadpole’s intestinal cell. Through that he showed that developed cells carry the information to make every cell in the body – decades before other scientists made world headlines by cloning the first mammal from adult DNA, Dolly the sheep.
More than 40 years later, Yamanaka produced mouse stem cells from adult mouse skin cells by inserting a small number of genes. His breakthrough effectively showed that the development that takes place in adult tissue could be reversed, turning adult tissue back into cells that behave like embryos.
These “stem cells” created from adult tissue are known as “induced pluripotency stem cells”, or “iPS” cells. Due to this, that actually patients may one day be treated with stem cells from their own tissue, their bodies might be less likely to reject them.
“The eventual aim is to provide replacement cells of all kinds,” Gurdon’s institute explains on its website. “We would like to be able to find a way of obtaining spare heart or brain cells from skin or blood cells. The important point is that the replacement cells need to be from the same individual, to avoid problems of rejection and hence of the need for immunosuppression.”
For now, both men said their scientific work continues.