Stem cell scientists have pinpointed a molecule that confers the cells with amazing powers of self-renewal and maintains their ability to develop into any other type of cell in the body.
The discovery could help pave the way for stem cells derived from adult tissues, giving ethical debates over the use of embryos a side-swerve.
A University of Edinburgh team, writing in Nature, reports that the protein Nanog acts as a switch, turning on a host of genes which are responsible for stem cell's much-touted special properties of renewal and repair. It's hoped they will provide treatments for currently incurable conditions such as Parkinson's and spinal cord injury. The stem cells in adult tissues do not have the same breadth of potential as those found in embryos.
The researchers induced mouse cells to produce extra quantities of Nanog. They showed when the Nanog cells were joined with cells previously destined to become nerves they were pushed back in time, regaining the ability to become other tissues. Dr Jose Silva told Reuters: "The effect of Nanog is remarkable. All the hybrid cells became fully converted to embryonic stem cells."
Although not the only controller of stem cells, the team say the work on Nanog - named after the Celtic mythical forever-young land of Tir Nan Og - is an important step to understanding the mysteries of what stops them becoming differentiated tissues.
Harvard recently announced plans to use private cash to fund research into using human embryos as a source of stem cells. ®