Posted on 03/31/2010 9:24:28 PM PDT by neverdem
Key difference between reprogrammed adult mouse cells and embryonic stem cells discovered.
Stem-cell researchers have puzzled over why reprogrammed cells taken from adult tissues are often slower to divide and much less robust than their embryo-derived counterparts.
Now, a team has discovered the key genetic difference between embryonic and adult-derived stem cells in mice. If confirmed in humans, the finding could help clinicians to select only the heartiest stem cells for therapeutic applications and disease modelling.
Induced pluripotent stem (iPS) cells are created by reprogramming adult cells, and outwardly seem indistinguishable from embryonic stem (ES) cells. Both cell types are pluripotent — they can form any tissue in the body.
Yet subtle distinctions abound. Last month, for example, Su-Chun Zhang and his colleagues at the University of Wisconsin–Madison compared the ability of both types of pluripotent cell to form human neurons in a laboratory setting, and found that iPS cells did so with markedly lower efficiency than ES cells (B.-Y. Hu et al. Proc. Natl Acad. Sci. USA 107, 4335–4340; 2010).
Last year, researchers also reported consistent differences in gene expression between the two cell types (M. H. Chin et al. Cell Stem Cell 5, 111 - 123; 2009). However, because scientists have always obtained iPS and ES cells from different sources — in general, iPS cells are derived from skin samples taken during biopsies and ES cells from excess embryos from fertility clinics — it was impossible to tell whether the discrepancies could be chalked up to the unique biology of the cells or the genetics of the underlying tissue.
A team led by Konrad Hochedlinger at Massachusetts General Hospital in Boston has now derived iPS and ES cells with identical DNA. The iPS cells were less efficient than the ES...
(Excerpt) Read more at nature.com ...
stem cell ping
This is not good news for our side.
Means nothing. These guys have yet to use ESCs in a successful therapeutic setting.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.