Study: Adult stem cells NOT (yet) = to embryonic stem cells

[bryce]

New studies are showing that reprogrammed, or "induced", adult stem cells have more genetic damage than embryonic stem cells - and are not yet an equivalent replacement for them:

From Science Friday: http://www.sciencefriday.com/program/archives/201103046

And...

Discover: Worrying genetic changes in reprogrammed stem cells

Mutations found in human induced pluripotent stem cells (UCSD press release)

The original paper (I believe)
Nature: Stem cells: The dark side of induced pluripotency (subscription required)

 

[farmkid]

Adult stem cells aren't the same thing as induced pluripotent stem cells (iPSCs). Adult stem cells are stem cells that are isolated from differentiated tissue (bone marrow, liver, blood, etc.) whereas embryonic stem cells come from the inner cell mass of a blastocyst (a very early stage of development at which the embryo is a hollow ball of cells). iPSCs are differentiated cells that have been de-differentiated by artificially causing them to express a few certain genes. They seem to function exactly like (or pretty damn close, anyway) embryonic stem cells.

iPSCs caused a lot of excitement when the technique was first reported a few years ago because (1) they provide a way to get embryonic stem cells(ESCs) easier and without the ethical issues of ESCs and (2) perhaps more importantly, the method provides a way to essentially produce ESCs from other cell types. This is especially important for therapeutic applications, because they could be derived from a person's own cells and therefore not require immune suppression as ESCs would.

This news is rather troubling. The fact that these genetic problems were found in both ESCs and iPSCs may prevent the use of either one for medical therapies. Yes that's right, either kind of cell. Even though iPSCs have more genetic abnormalities than ESCs, the fact that they're seen in ESCs as well is a problem for their use.

I know a number of people doing research in this field, and I've been considering jumping into it myself, and if this turns out to be an insolvable problem it will be disappointing, to say the least, to many of my colleagues. The leaders in the field are just now figuring out how to produce iPSCs without any viral vectors--meaning that they can be made without leaving anything behind in the genome from the experimental manipulation. In other words, the technology is just getting to the point where these cells could have potentially replaced ESCs in any medical therapy (assuming there were any non-experimental therapies utilizing ESCs). This news is a serious setback.

 

[SG-17]

Well they still work great for healing severe burns in days with no scarring.

 

[farmkid]

^If that's the technique I'm thinking of, they use a patients own stem cells derived from the blood. They aren't embryonic stem cells or induced pluripotent stem cells. They shouldn't have any of the issues mentioned here because they are simply removed from the patient, isolated away from other cells and then applied--they aren't even cultured.

 

[KJbushway]

I don't think stem cells are that good. Could they treat cancer-yes, without the risk of destroying your liver from radiation treatment.
The Japanese for years now have been expirementing with trying to get stem cells from adults by using different types of cells. The last article I read was about them taking cells from the adult hand.

 

[farmkid]

Actually, cancer is one disease where stem cells likely wouldn't be very useful. If anything, causing cancer is one of the potential risks of any stem cell treatment. Any stem cell that doesn't differentiate could easily become cancerous. In fact, embryonic stem cells have created teratomas (cancerous tumors with many miscellaneous differentiated tissues in them) just about any time they've been used as a potential treatment. The ability to create teratomas is one of characteristics used to define embryonic stem cells.

Stem cells are potentially useful in treatments where tissue needs to be repaired or replaced, such as wound healing, type I diabetes, Parkinson's disease, spinal cord injury, etc. There aren't many such treatments yet, and none using embryonic stem cells to my knowledge, but there are plenty of scientists working on it.

 

[KJbushway]

There was actually a test done down here in Georgia, where different people with spinal injuries where given stem cells. I haven't heard any news on the results yet.