nos-trum. pronunciation: \nos'-trum\. noun. Etymology: Latin, neuter of noster our, ours.
1. a medicine of secret composition recommended by its preparer but usually without scientific proof of its effectiveness.
2. a usually questionable remedy or scheme.
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Wednesday, July 28, 2010

Stem Cells Phone Home

 
Recent studies in the journal Nature suggest that stem cells produced from adult tissue may tend to revert to their cell of origin.

If true, it means the cells would be less useful for stem cell research.

The Washington Times reports (July 19) on the research, and the signal study is here in Nature (19July 2010).  Stem cells produced from adult tissue have some advantages:  there's a lot more of it around, you can convert them to partially differentiated cells of different types, and there's no need for embryo's to harvest the cells.  Unfortunately, in practice, they retain the genetic code to revert to the original tissue from which they came.
"Called "induced pluripotent stem cells" (or iPS), the altered adult cells "forget" they were once cells naturally "programmed" to become liver cells, lung cells, skin cells, etc. This would make them, theoretically, as useful as embryonic cells for a variety of miracle cures, especially for degenerative diseases such as Alzheimer's.

It turns out, the studies say, that they don't forget." (From Wash Times)
This study is observational, meaning the researchers haven't delved into why or how often this occurs, so these findings have to be considered preliminary.

The news report creates its headline from the speculation that this undermines the credibility of arguing that embryonic stem cells are not needed--that we can obtain just as much benefit from adult cells without engaging the moral repugnance some have for using embryo's.  This is a giant leap ahead of the science.

The news articled failed to report that the researchers also said that
"Such an ‘epigenetic memory’ of the donor tissue could be reset by differentiation and serial reprogramming, or by treatment of iPSCs with chromatin-modifying drugs."
In everyday English, you could treat those adult-origin cells to "reset" their stem cell capability.  This would restore their usefulness.

By contrast, while the researchers thought embryonic stem cells would be more stable, it's clear that stem cells from any source--adults or embryo's-- exist for the purpose of differentiating into specific tissue cells.

And embryonic cells are not immune to that process.

Bottom line, we need to wait and watch.  This research is still preliminary and it's too soon to be making claims about political and moral implications.

Doc D
 
 

2 comments:

Anonymous said...

Why isn't money pouring into all stem cell research? See which work and then make a decision..let this guy do his thing


Stem Cell Rock Star

UC Irvine’s Hans Keirstead is a charismatic, tradition-bending, action-figure of a researcher who not only wants to heal the sick, but change the way academic scientists do business. Is the world ready for him?
By Patrick J. Kiger


The UC Irvine stem cell researcher who startled the world by enabling paralyzed rats to walk—and aims someday soon to do the same for humans—is in his second-floor office at the Gillespie Neuroscience Research Facility, where the afternoon sun streaming through the window accentuates his tanned, finely chiseled features and the highlights of his lush mane.

http://www.orangecoastmagazine.com/article2.aspx?id=23896

Doc D said...

Sorry it took so long to reply. Thanks for commenting. I looked up this man's journal work. He seems a solid researcher, but the referenced article is what journalists call a "puff piece." Maybe you've heard the term; it's an uncritical rave, with superlatives ("charismatic," "finely chiseled"). A journalist did one on me once. It was embarrassing.

Anyway, he's doing some good work. Not as startling as this article sounds, but promising stuff.

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