Question about Demethylating drugs - (Nov/16/2008 )

Dear all,

I've been extensively using demethylating drugs during cell culture like 5-aza-2-deoxycytidine. The method of treatment is established a long time ago in our lab, we add the drug solution into the culturing medium and incubate for days. Can anyone share there ways in treating these drugs in cell culture?

Secondly, it is well known that 5-aza-2-oxycytidine is a more potent demethylating agent. However, when i am treating it to my cells, it got really low toxicity to the cells. I was told that the drug need to have toxicity effect to the cell that indicate it got demethylating effect on it, is it true??

I dunno if it is due to the problem that my 5-aza-2C is purchased for a long time, already more than 2 years. However, it is kept in 4C once it is delivered. Can anyone tell me the approximate stability of this drug?

Thanks in advance.

one other thing to check is to see if your model system is resistant to the drugs, they require a phosporhylation step to become active and incorporate into replicated DNA (essential for demethylation) if they don't have this activity then the drug is useless.

We treat with nM-uM quantities over three days and supplementing/refreshing the media with fresh drug each day (the half life of the drug is not long anyway-I think from memory it's hours-days)

good luck

Nick