Thread: un-differentiation

can a cell that has been differentiated into its specific type possibly be un-differentiated? and if it was, wouldn't this give rise to a stem cell? i'm wondering what the mechanism would be...because ultimately how a cell develops is genetic, so would it be possible to switch some stuff on and off and get a cell to just become a "plain" cell?

Correct me if I am wrong, but I believe that some of the non stem cell's genes are 'turned off' or 'deactivated'. I am sure noone has come to a conclusion about where this disablement takes place during the creation of a specific type of cell. However, there is a moment and a device somewhere within the cell that does this. We just don't know what it is and when it takes place.

So, I am sure that a specifity cell could be reverted back into a stem cell. But, it will take some more research to figure it all out.

Most genes in any one cell at anytime are turned off! Yes, differenciated celld have been reverted back to stem cells (its been done mostly with blood cells) but it the result is not as good as it would be using embryonic stem cells as only som tissues can be produced from these reversed blood cells. It's still becoming a massive area of research as there are no ethical issuues with doing this compared to using embronic stem cells.

The book I red about the matter is kind of outdated, so I was not sure if anything has come about from research. But, it's good to know that the possibility is there. Yay

Originally Posted by Robbie

(its been done mostly with blood cells)

i'm guessing that's white blood cells? because red blood cells don't have nuclei... but anyways, yeah, that's interesting. definitely an area they need to keep working in.

Yeah, must be, Im actually having difficulty finding public information on it in detail, but this shows it is being done!
http://newsbusters.org/node/11702

The first I heard this a few years ago a dutch couple of scientists were reversing the differenciation of blood cells; this may have been white cells (but there are many subclasses of white blood cell so they may have used developing red cells/ megakaryocytes which would still have nuclei.)
Hopefully in a few years there wont be any need for embryonic stem cells!

Lots of cancers will contain stem cells.
The cells divide so quickly that the cells cannot differentiate, and telomerase will be activated. Voila! You have a stem cell!

that's actually one o the theoretical fears of stem cells; that they may become oncogenic and cause cancer. I doubt cancer cells are considered stem cells.
Is telomerase activation involved in stem cells or what do you mean (I know the role of telomerase in cancer etc but what do yoou mean regarding stem cells)?

I read a nature paper a few years back about how some tumours actual will contain stem cells.

And the reason I mentioned telomerase is because i just read a paper about that particular enzyme about 2 days ago, so it was still fresh in my mind.

Artandi, et al. Conditional telomerse induction causes proliferation of hair follicle stem cells. (2005) Nature.

I don't know how much you know about telomerase .. but it is a riboprotein (with the RNA providing a template for the telomere repeats), and when TERT (the protein compent) is active, it causes stem cells to proliferate ... without TERC (the RNA component). SO that means it has some sort of double function.

But that is off topic

I recently picked up somewhere that someone named Catherine Verfaillie is doing research on these adult stem cells. But there's been a lot of controversy here in Belgium, due to the fact that she might have messed up, and that her experiments aren't repeatable etc., don't really know everything.

And maybe the differentiation of stem cells has something to do with DNA methylation and/or acetylation?