Kat - And another story that we saw this week was published in the journal Cell from Jeannie Lee and her team in Boston, finding potentially a use for another RNA called Xist in blood cancers. Now, youíve heard of Xist haven't you, Nell? What does it do?
Nell - So, this is interesting. I like this because itís going back to that nice idea of, youíve got your 2 X-chromosomes in a female and for that to work in a functional organism, you want to deactivate one of those because otherwise youíve got two copies of every gene, everything will get a bit out of control. So, Xist is there that helps to switch off one of those X-chromosomes. Itís a little piece of RNA thatís doing that job.
Kat - Itís the only gene thatís actually made by your switched off X-chromosome, I think.
Nell - This is looking at what happens when you knock that out. So, could having two switched on copies of the X-chromosome be causing specific problems and can we find out by using this little piece of RNA to switch it off?
Kat - So, they did some really nice experiments where they actually got rid of this Xist RNA and they completely knocked out the gene that made it in mice. Then it caused problems with their blood. And actually, if you look at patients who have certain types of blood cancers, you do see problems with some of their X-chromosome genes and actually, other genes as well. So maybe they think that Ďexistí might be playing a much wider role in cells. Itís a really fascinating, intriguing paper.
Nell - Yeah and I like the Ė there was an interesting point they made at the end that some forms of leukaemia-type precursor disorders are more common in women and you can see immediately there that could be something going on there with the fact that you have got those two X-chromosomes. And if something is going wrong, meaning that perhaps parts of one are active and they shouldnít be. Perhaps thatís the link there, so thatís quite an interesting little trend they can see in this data.