Stand Up For Science

In a post a couple of weeks back we highlighed the key contributions made
by animal research to the development of techniques to create induced
pluripotent stem cells by using genetic modification to reprogram human
skin cells.

http://www.pro-test.org.uk/b2evo/index.php?blog=7&title=miracle_in_a_test_tube_thanks_to_animal_&more=1&c=1&tb=1&pb=1

At the time we noted that a major problem identified during mouse studies
by Professor Shinya Yamanaka was that a significant proportion mice
produced from reprogrammed cells developed tumours. It was thought that
one of the four genes that Prof. Yamanake used to reprogram the cells, a
notorious oncogene called c-Myc, was responsible for the problem.

In a study published online in the journal Nature Biotechnology Prof.
Yamanaka has demonstrated a new protocol that does not involve c-myc.
With this new protocol he has been able to produce induced pluripotent
stem cells from both mouse and human skin cells. What is more these new
stem cells were not only of high quality, but mice derived from them did
not develop tumours.
http://www.nature.com/nbt/journal/vaop/ncurrent/full/nbt1374.html

In another study published online in Science this week Professor Rudolf Jaenisch and Professor Tim Townes have used reprogrammed cells to successfully treat sickle cell anemia in mice. They first produced induced pluripotent stem cells from the skin cells of mice with sickle cell anemia, next they replaced the defective hemoglobin gene in with a healthy gene and coaxed these mended stem cells to become blood stem cells. Finally they injected the blood stem cells into sickle cell mice whose own defective blood producing system had been partially destroyed by radiation. Subsequently the symptoms of sickle cell anemia were found to be much reduced in the treated mice, and their general health was much better than untreated sickle cell mice.

http://www.guardian.co.uk/science/2007/dec/07/stemcells
http://sciencenow.sciencemag.org/cgi/content/full/2007/1120/1

This is excellent news and provides further evidence that reprogramming cells may be a practical way to produce stem cells for therpeutic purposes.

Paul Browne