5-Aza-2'-deoxycytidine - (Sep/29/2004 )

Hi,

I've been thinking of how 5-Aza-2'-deoxycytidine really works. It demethylates methylated cytosines, but how? And if every promotorregion gets unmethylated and the genes are turned on, how do the cells survive? And what about the regions covering the coding part of genes, that are normally methylated, I guess these get unmethylated as well...
Can anyone explain this for me?!

Hi,
as far as I know 5-Aza-C is quite toxic to cells and they can't survive very long with it. It depends on the concentration of course. But it's not a "nice" chemical

Thanks for your reply,

does anyone know more about how it works molecularly? Does 5-AZA get incorporated in DNA or how does it demethylate?

It is incorporated into DNA or RNA and then covalently link with DNMT. DNMT will be depleted by being bound to zaz-cytindine and is thereby unavailable for methylation.

OK,
5-AZA gets incorporated into newly synthesised DNA strands. DNMTs get bound to this "modified" cytosine, which make DNMTs unable to methylate the new strands. Do I understand it correctly? That means that every gene that is supposed to be turned off is turned on. The cells can't be felling that great...
Is it really possible to make accurate expression studies in the chaos?

Thanks again!