Dedifferentiation
Stem cells are hoped to become the next “killer app” in medical therapeutics–creating new organs and tissues that have been destroyed from disease or cancer, for example; they’re already the basis for today’s bone marrow transplants. But the subject is plagued with issues both technological and ethical . In the former case, it’s proven difficult to use (or even find) an adult’s own stem cells. They’ve recently been found in heart muscle , and can be used in rats to reconstitute damaged heart tissue, and they’re known to be present in bone marrow, but stem cells still haven’t been found in most other tissues.
Ethical issues abound as well. While embryos contain a great number of stem cells (known as embryonic stem cells), there are numerous conflicts surrounding life and death, and the very hair abortion issue. President Bush ruled 2 years ago that researchers could continue working with the embryonic stem cell lines that had already been developed, but that no new lines would be allowed. Cells from fetuses aren’t allowed either, although they are now correctly defined as omnipotent (able to give rise to multiple cell types), as opposed to totipotent (able to give rise to every cell type necessary for life.)
But according to some Scripps researchers , we may be able to avoid most of the problems associated with embryonic and adult stem cells. In the Journal of the American Chemical Society, they claim to have been able to dedifferentiate cells –that is, reverse their clocks, turning them back into their precursor cells. It’s based on the ability of some amphibians to regrow their tails and other tissues; at the site of injury, cells gather, are exposed to a certain chemical, which then allows the cells to go back to their immature state and become the multiple types of tissues needed to regrow the tail. The researchers took muscle cells (myotubes), added 50,000 different chemicals to them, and found that one they named reversine was able to turn adult muscle cells back into precursor cells, myoblasts. It’s still initial research, and needs to be reproduced and studied more, but the possibilities are profound–not only for therapeutics, but for redefining the human developmental dogma about cell maturation.