Now, I know what you're thinking: So suddenly scientists discover they can indeed reprogram adult skin cells back to a pluripotent state, the pro-life community goes wild with joy, the end of the stem-cell wars seems to be in sight, and Lydia gets cold feet about biting the bullet she said she would bite on exactly this sort of reprograming. (Mixed metaphor alert.)
Those of you who slogged through my earlier ANT-OAR post will remember that I said that making pluripotent stem cells like embryonic stem cells in the lab is wrong even if it doesn't involve making and destroying any live embryos, because it is analogous to making a "headless body," which is macabre and prima facie unethical. At that time I admitted that a counterintuitive consequence of this position is that it would be similarly unethical to make such cells by reprograming adult cells back to a pluripotent state, but that I was prepared for the nonce to bite that bullet.
So why am I rethinking?
Well, the cause of my second thoughts is only incidentally related to the recent explosive news of success in reprograming adult cells. In the course of reading about that research, I found out an empirical fact I never knew before: It seems that a small number of pluripotent cells are found free "in nature" in umbilical cord blood and in bone marrow. These cells are known as VSELs (very small embryonic-like cells). See also several abstracts here. They have not been fully tested for pluripotency, and scientists seem unsure as to whether they will pass the teratoma-formation test for full pluripotency (see here), but all the signs so far are that they are indeed exactly like the cells of the inner cell mass of a blastocyst.
What I'm still a bit mystified about is why that discovery didn't end the stem cell wars already, even before the reprograming breakthrough. Why bother reprograming to pluripotency if we all have a few pluripotent cells floating around in our bone marrow already? Just isolate them and culture the heck out of them, and there you go. My only conjecture in response to that so far is that VSELs are apparently very rare, so maybe it just isn't possible to get enough of them, even with culturing.
But if indeed cells just like those of the inner cell mass exist in the human body naturally, this seems to me to call seriously in question the thesis that such cells are like "the dead bodies of embryos" or that inducing them in the lab would be like making a faceless Frankenstein monster. Prima facie, cells that are a normal part of the adult body are not analogous to such an unnatural entity and are not unethical to make.
While normally I hate to have to change my mind publically as much as anyone else, in this case (as you can imagine), I'm not too sorry. After all, that means that I, too, can be pleased about the reprograming breakthrough along with the rest of the pro-lifers in the country.
As to what this means about ANT-OAR, I'm not sure. One of the reasons I'm not sure is that, as I noted in the comments thread to my earlier post, ANT-OAR has not been well-tested in animal studies yet, and there is a real ambiguity in its proponents' writings on how techniques involving gene knock-out differ from techniques involving the introduction of positive factors. This leaves open the possibility that a damaged embryo is created in ANT-OAR, a possibility that can't be ruled out until more testing is done. That point may be practically moot, however, as it seems to me that in view of the reprograming success, ANT-OAR--with its cloning-like aspects and its need for human eggs--is unnecessary.
But in the main earlier post, I was granting for the sake of the argument that ANT-OAR could indeed create ICM cells without making a live embryo, and I was arguing that this would still be wrong. If it is actually true that a small number of cells like ICM cells are a normal part of the adult body, it seems to me that that conclusion must be incorrect.
HT Life Ethics
Comments (5)
If it is actually true that a small number of cells like ICM cells are a normal part of the adult body, it seems to me that that conclusion must be incorrect.
I'm not following. I've never thought that being in possession of a cell or cells from the ICM was in itself wrong, but was only concerned with the means of procuring them. These cells that normally occur in the body are not part of an embryonic integrity. To capture and use them does not require violating that integrity. Even reprogramming them to a state of embryonic potency neither creates nor destroys an embryo (as far as I know, which may not be very far). Shouldn't our objection be to any act of conception, or any technique (like cloning) that imitates conception, which results in either a living, a defective, or a dead embryo, for the purpose of acquiring those cells?
In your earlier post you said: "To those who believe in the human sacrifice that is embryo-destroying research, nothing less than full freedom, with federal tax funding, to pursue that avenue is acceptable."
Even with this skin-cell breakthrough, I'm doubtful this will change, because I suspect that this particular avenue of scientific research is not all about what "works best," but about that freedom you mention, known under other auspices as Roe v. Wade.
Posted by William Luse | November 25, 2007 4:02 AM
Well, in my earlier post I had argued that ANT-OAR is wrong even if it succeeds as its proponents hope in making ICM cells without first making (and hence requiring the killing of) a living embryo. My argument in that post was that this is wrong because the ICM cells are analogous to a body without a head, since they are what would otherwise develop into the embryo (except for the placenta) and are in _ordinary_ embryo-destroying research obtained by stripping off the trophoblast layer from an embryo. So the idea was that you were doing something like making a dead embryonic body without its trophoblast.
Now if that were true, and if making a "body without a head" is in fact always wrong, then making a "body without a head" would be wrong even if it were done by reprograming adult skin cells. I mentioned that in the earlier post as the strongest objection to my argument there, because there just doesn't seem, intuitively, to be any problem with reprograming adult cells to a pluripotent state.
But at that time I was under the impression that pluripotent cells exist in nature only in the ICM. (What are usually referred to as "adult stem cells" are not pluripotent but multipotent.) I didn't know that there are apparently these VSELs which are naturally-occurring pluripotent cells in the adult body. If they really are just like ICM cells, then it looks like making ICM cells _isn't_ analogous to the macabre activity of "making a body without a head"--that is, making a dead embryonic body by just making ICM cells.
You're certainly right that it is the cloning-like nature of the ANT-OAR technique that has raised questions in the first place. And I think it is that technique that still keeps a question mark over ANT-OAR as to whether it produces an embryo or not. The truth is, they just don't seem to have tested it much yet. But my supposedly original contribution in the earlier post consisted in raising that question and then, for the sake of the argument, setting it aside. Suppose ANT-OAR doesn't make a live embryo? What then? That was where I was going there.
It wouldn't be the first time in my life that, in trying to be original, I simply ended up being wrong. In this case, however, it isn't so bad to be wrong.
Posted by Lydia | November 25, 2007 2:41 PM
I'm not yet convinced you were wrong. I guess we'll have to wait and see.
Posted by William Luse | November 26, 2007 2:22 AM
Unfortunately, if I was right, then as far as I can see they shouldn't be reprograming these adult cells back to a pluripotent state, because that way they are also making the analogue to headless bodies. Unless one argues (which I didn't) that only a cloning-like technique can have this result. But I'm not sure why that should be so, if it's the physical outcome--the "headless body"-analogue cells--that is the problem.
Posted by Lydia | November 26, 2007 8:46 AM
Unless one argues (which I didn't) that only a cloning-like technique can have this result.
Well, that's the big question, and the reason for my emphasis on means which either employ or imitate conception. I hadn't thought that a pluripotent cell from the ICM was itself capable of becoming an embryo, but that its status was more like that of an organ, say a kidney in a born human. (It would still be immoral to take it, even if it wouldn't kill the embryo.) In other words, I had assumed that if we could come by one of these cells without its source having been in, or having passed through, an embryonic stage, that it would be a good thing because the cell had never been, nor ever could be, a person. Prior to this recent breakthrough, the procedures employed (including ANT-OAR) relied on techniques that effect conception, the cytoplasm of the egg cell seemingly crucial to success. This is not the case with re-programmed adult cells. Unless you're saying that sending an adult cell back to pluripotency is in fact just another form of cloning, so that there attaches to the reprogrammed cell a dignity normally reserved for persons, whether defective or healthy, alive or dead. And that would mean it is an entity other than what I thought it was.
Which is why I need you to keep digging into this. :~)
And all the above is of course offered with any caveats that ought to accompany biological ignorance.
Posted by William Luse | November 27, 2007 1:32 AM