I’m most familiar with gene therapy issues causing cancer, but that might be an availability bias—in those studies where gene therapy simply kills the relevant cells, I’m sure very little is published.
The traditional way of inserting a gene into the genome is to use a retrovirus with its DNA replaced. Most such viruses (at least, that have been used) incorporate randomly, meaning that there is a small but nonzero chance every time a new cell is modified that it will knock out a gene that is important for controlling cancer. On a cellular level, the most likely cause of this is cell death, as the rest of the cell’s anticancer mechanisms shut down the cell. But of course, this doesn’t work every time.
There are specific viruses (i.e. that always integrate at the same, safe genomic location) currently being developed, and it’s hoped that these will solve the problem.
However, there’s actually another related problem. If you want to make major changes to the cell (like reprogramming it into a stem cell), the cell’s anticancer mechanisms will detect that as well, so in order to make those changes you have to at least temporarily shut off some of those mechanisms. So there is a risk for cancer in that as well.
About the topic of this thread—generally, the ability to survive specific extreme environments (especially one that affects everything in the cell such as changes in water content or temperature) is a specialized adaptation. I would not be surprised if there are global differences in the genomes of these species, e.g. most proteins are much more hydrophilic, or there is a system of specialized chaperones (=proteins that refold other proteins or help prevent them from misfolding) plus the adaptations in proteins that allow the chaperones to act on them, and further systems to repair damage the chaperones don’t prevent. It is unlikely that only a few genes would be involved, and unless a case can be made for evolutionary conservation of the adapted genes to humans, we wouldn’t have most of them (in fact, any genome-wide changes would mean that we would have to adapt our own proteins in new ways, just because we don’t share all of them with the species in question). Cold temperature is actually a special case here, because it slows down everything and thus reduces the amount of “equivalent normal-temperature time” that has passed. It’s still difficult (and of course none of these are impossible), but I don’t think it’s likely that small-scale gene therapy would be sufficient.
Why is global cancer the primary risk rather than not being viable at all?
I’m most familiar with gene therapy issues causing cancer, but that might be an availability bias—in those studies where gene therapy simply kills the relevant cells, I’m sure very little is published.
The traditional way of inserting a gene into the genome is to use a retrovirus with its DNA replaced. Most such viruses (at least, that have been used) incorporate randomly, meaning that there is a small but nonzero chance every time a new cell is modified that it will knock out a gene that is important for controlling cancer. On a cellular level, the most likely cause of this is cell death, as the rest of the cell’s anticancer mechanisms shut down the cell. But of course, this doesn’t work every time.
There are specific viruses (i.e. that always integrate at the same, safe genomic location) currently being developed, and it’s hoped that these will solve the problem.
However, there’s actually another related problem. If you want to make major changes to the cell (like reprogramming it into a stem cell), the cell’s anticancer mechanisms will detect that as well, so in order to make those changes you have to at least temporarily shut off some of those mechanisms. So there is a risk for cancer in that as well.
About the topic of this thread—generally, the ability to survive specific extreme environments (especially one that affects everything in the cell such as changes in water content or temperature) is a specialized adaptation. I would not be surprised if there are global differences in the genomes of these species, e.g. most proteins are much more hydrophilic, or there is a system of specialized chaperones (=proteins that refold other proteins or help prevent them from misfolding) plus the adaptations in proteins that allow the chaperones to act on them, and further systems to repair damage the chaperones don’t prevent. It is unlikely that only a few genes would be involved, and unless a case can be made for evolutionary conservation of the adapted genes to humans, we wouldn’t have most of them (in fact, any genome-wide changes would mean that we would have to adapt our own proteins in new ways, just because we don’t share all of them with the species in question). Cold temperature is actually a special case here, because it slows down everything and thus reduces the amount of “equivalent normal-temperature time” that has passed. It’s still difficult (and of course none of these are impossible), but I don’t think it’s likely that small-scale gene therapy would be sufficient.
Cancer sounds like not-viable to me :P
I meant not even being viable enough to get cancer.