CAMBRIDGE, Mass. (October 10, 2007) – The protein Oct4 plays a major role in embryonic stem cells, acting as a master regulator of the genes that keep the cells in an undifferentiated state. Unsurprisingly, researchers studying adult stem cells have long suspected that Oct4 also is critical in allowing these cells to remain undifferentiated. Indeed, more than 50 studies have reported finding Oct4 activity in adult stem cells.
But those findings are misleading, according to research in the lab of Whitehead Member Rudolf Jaenisch.
In a paper published online in Cell Stem Cells on October 10, postdoctoral fellow Christopher Lengner has shown that Oct4 is not required to maintain adult stem cells in their undifferentiated state in mice, and that adult tissues function normally in the absence of Oct4. Furthermore, using three independent detection methods in several tissue types in which Oct4-positive adult stem cells had been reported, Lengner found either no trace of Oct4, or so little Oct4 as to be indistinguishable from background readings.
This means that pluripotency, the ability of stem cells to change into any kind of cell, is regulated differently in adult and embryonic stem cells.
“This is the definitive survey of Oct4,” says Jaenisch, who is also an MIT professor of biology. “It puts all those claims of pluripotent adult stem cells into perspective.”
Why does this matter one whole heck of a lot? If we could turn adult stem cells into pluripotent stem cells (i.e. into stem cells that can then become all other types of cells in the body) then we might not need embryonic stem cells for that purpose. If we could reduce the need for embryonic stem cells then research into pluripotent stem cells would probably progress more rapidly.
Cellular differentiation is the process by which stem cells become specialized cell types such as muscle cells, nerve cells, skin cells, and liver cells. Research into genes that control differentiation is also generally useful for efforts to develop replacement organs and other replacement body parts. We need to know how all the genes that regulate differentiation interact with each other in complex signaling networks. We also drugs, gene therapies, techniques that can control the process of cellular differentiation. The ability to control cellular differentiation will give us replacement parts as our bodies wear out.
|Share |||Randall Parker, 2007 October 10 08:58 PM Biotech Stem Cells|