Per conversation with Julien the cost per mouse is ~2K and one mouse yields 3-10 dissectible tumors and a few mets. The GFP system is up and running and in principle we can use it for the purposes of the project.
So for 100K we could get 50 mice and sacrifice them at 4 stages: early, middle, late, very late. Early is when the experience shows that the first lung tumors appear. Middle - around the time the first mets appear. Late - multiple mets. Very late - close to death.
This way we would get ~12 mice per time point and a fairly large number of tumors (50*~5=250 tumors and 200-400 mets).
We can then sequence deeply the late ones and do targeted resequencing of the intermediate stages focusing on all of the mutations that we found in the late stages. We can also do RNAseq on them.
Julien, any thoughts?
we could get different stages, although not all the tumors are synchronous, i.e. if you sac 2 mice 4 months after cancer induction, some mice will have a couple of advanced tumors and many intermediate tumors, while other mice will have only smaller or intermediate tumors... Also, it is sometimes hard to get single tumors and easier to just get tumor cells from an entire lung lobe - so, all of this is possible, but practically is not as simple as the way you described it.
ReplyDeleteAlso, another way to "age" the tumors is to harvest them from the mice, and then re-transplant them into other mice, and then re-harvest, etc... this way, tumors can be produced that are much more than 6 months.
Ok, so what would be agood exp design to start with?
ReplyDelete1. 50 mice sacrificed at what intervals?
2. I love the idea of retransplanting early tumors
3. Can we retransplant mets?
yes, we can retransplant mets, and they form mets again :-)
ReplyDeletemaybe 50 mice is to much, but intervals could be every other week - at first, pooling the few GFP cells from all the lobes of the lung, and then getting individual tumors...
Awesome. I think 50 mice is a minimum to get staging, no? Also, want to get a sense of the whole scale necessary.
ReplyDelete