Summary: Biologists Make Skin Cells Work Like Stem CellsJune 12th, 2007
Dr. Bernstein summarizes a New York Times article on stem cell research:
A major advance in regenerative medicine has recently been announced. A new technique, which can convert adult skin cells into embryonic form, has been successfully performed on interbred mice by Dr. Shinya Yamanaka of Kyoto University. The technique, if adaptable to human cells could allow new heart, liver, or kidney cells to be regenerated from simple skin cells. This tissue could potentially replace organ tissue that has been damaged due to disease. As this tissue would be formed from the patient’s own skin cells, it would not be subject to rejection by the patient’s immune system.
Prior to this discovery, the conversion of an adult cells into embryonic cells was done only through nuclear transfer; the implantation of the nucleus of an adult cell into an egg. The egg then reprogrammed the adult genetic material into an embryonic form.
This new technique involves the insertion of four genes into a skin cell. These genes would then complete the reprogramming of the nucleus of the skin cell into embryonic form, just as the egg had in nuclear transfer.
If adaptable to human cells, this could provide a simple, inexpensive and politically uncontroversial technique for regenerating stem cells. It should eliminate the ethical debates regarding stem cell research.
But this discovery does not mean that cloning will be available anytime soon. There are many obstacles which must be overcome prior to its implementation. The most immediate problem is discovering if this technique, which has been performed only in mice, can be used successfully with human cells. Another problem is that the mice that were used in the experiment were interbred, something obviously not acceptable for humans. In addition, the cells must be infected with a gene-carrying virus, a process that may not be safe for humans. Finally, two of the four genes which are needed to begin this regenerative process are carcinogenic (potentially cancer forming). In fact, 20% of Dr. Yamanaka’s mice died of cancer.
Although scientists cannot begin to predict when these considerable problems might be overcome, they are still confident in this advancing breakthrough and that these obstacles will someday be overcome.
Reference: Biologists Make Skin Cells Work Like Stem Cells by Nicholas Wade, NYT, June 7, 2007