Published Oct 1, 2007 8:00 AM
Religion and science collide on the subject of stem cell research. But what if we could avoid the politics? What if normal tissue cells could be made to do what stem cells do? In mice, at least, they can.
In June, UCLA researchers, working closely with stem cell scientists at Harvard, discovered that a simple technique can prod mouse cells to return to their embryonic state, in effect "reprogramming" normal cells into cells with the same unlimited properties as embryonic stem cells. If the technique proves successful with humans, it could be a lifesaving breakthrough, a cheap and easy way to generate a limitless supply of cells to replace those damaged by injury or disease.
Because of their ability to give rise to every cell and tissue type in the body, embryonic stem cells are invaluable as research tools and for their potential use in treating numerous ills, from heart disease and diabetes to Parkinson's and spinal cord injury. But the technique for obtaining human stem cells — extracting them from a destructed embryo — is controversial, which has limited federal funding. Moreover, the only previously known method for reprogramming adult cells into embryonic ones has been through somatic cell nuclear transfer (SCNT), sometimes referred to as "therapeutic cloning." In addition to raising ethical concerns, SCNT — in which the unfertilized egg is used to reprogram the nucleus of a cell back to its embryonic form — is technically difficult and has never been successfully done in humans.
The technique used by the team from the UCLA Institute for Stem Cell Biology and Medicine, Harvard and MIT is far less complicated. The scientists added four transcription factors — proteins that control when genes are turned on and off — to skin cells in mice. Remarkably, the reprogrammed cells were indistinguishable from embryonic cells.
For now, the impact is limited to the laboratory, but the implications obviously are staggering. So the UCLA team and many others around the world are hard at work trying to re-create the cell reprogramming in human cells.
"Nuclear transfer takes a lot of training to do and is inefficient," says the institute's Kathrin Plath, assistant professor of biological chemistry and co-lead author of the study. "Our method is so easy that potentially any lab in the world can do it, and much more efficiently."