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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Friday, October 1, 2010

Stem Cell Research Update: New Route To Use Adult v. Embryo Cells

 
Stem cells again.  More evidence that cells from skin can work as effectively as stem cells from embryos...in some cases.

Readers can review my previous posts on this issue here and here.  I don't consider the question settled as to whether we can use adult stem cells (from skin and other tissues) in all cases where stem cells may be effective as the basis for new treatments of disease.  Nor is it settled that we must have stem cells from embryos for at least some research purposes.

I wrote previously that there is a theoretical problem with adult stem cells:  they may be more prone to revert to the cell-type from which they came.   But there's no evidence that they will do so when used clinically...like I said, theoretical problem.

Why do we care where the stem cells come from?  The political controversy over embryonic stem cells began with concern over the indiscriminate production and destruction of human embryos for the purpose of harvesting stem cells.  Subsequent regulations limited the circumstances under which embryonic stem cells could be produced and harvested.  Although there's been a lot of acrimonious debate, the real differences between the political parties are not that big.  The Bush administration, widely accused of halting embryonic use actually allowed already established cell lines to continue.  By contrast, the Obama administration has approved several dozen more cell lines, but still upholds the ban on producing embryos for the purpose of getting stem cells.

Beyond the political hoopla, adult stem cells have made great advances, since their use has never been restricted.  Who cares whether we scrape off some skin cells of a consenting adult?

However, adult stem cell research has a couple of stumbling blocks to overcome.  One, it's harder to get a large amount of them, and two, you have to modify the cell's DNA to get it to convert to a stem cell.

Now comes a study, from the journal Cell Stem Cell (Sep 30),that outlines a method of making adult stem cells more efficiently and being able to direct them into the type of stem cell you want to make...without having to jinky with the DNA.  Making changes to the genes themselves, the DNA, risks causing other changes that could lead to the cells becoming more prone to cancer, for instance.

This new method creates induced pluripotent stem cells (iPSC).  The process changes the protein coded by the DNA (messenger RNA, or mRNA) which is responsible for directing the synthesis of the cell's functional machinery.  The changed machinery then operates as a stem cell.  The DNA (or genes) remain unchanged.

This opens a new avenue for the use of adult cells, and avoids the moral opprobrium (felt by some) with the use of embryos.

This won't be the last word on the issue, just an update.  We may find that there are certain diseases for which we can't make stem cells work from only one source--adult or embryo. 

My guess is the answer is not a political one, but comes from the science of what we can develop and what can cure disease.

Doc D
 
 

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