I saw Ron Reagan Jr. at the Democratic Convention this evening touting stem cell research, and IMO this is a worthy endeavor. I’ve read a little bit about the subject and it seems quite promising, but kind of far off. In his speech he made it sound as if stem cell therapies were just a few years away, instead of 10-20 years distant.
What’s the straight dope on how close or far way useful stem cell therapies are?
I dunno about it being a “magic bullet:”
“Combi-chem” (combinatorial chemistry) was touted as being the wave of the future for drug and material science research. It wasn’t.
Once we unravelled the human genome, many pundits claimed, disease would be a thing of the past. The human genome has been decoded. Big whoop.
“Proteomics” was supposed to make everything clear. You don’t hear much about it these days.
Basically all of these disciplines have provided all sorts of new information, and have supplied lots of missing information, but I have found that the biggest boosters of any given techology tend to have some vested interest in seeing it succeed.
It does seem promising, but not nearly as Ron Reagan Jr. made it sound. For one thing, you can’t just whip up a batch of dopaminergic neurons and inject them into your brain and expect that to cure Parkinson’s disease. Using stem cell-derived neurons to treat Parkinson’s would require selectively replacing damaged neurons, and may halt or even substantially reverse the progress of the disease, but it would not ‘cure’ it instantly. Other conditions that he mentioned might have been a better example. Paralysis or diabetes involve cells that may be easier to target. While there might be some scientific merit in the use of stem cells to treat various conditions, it is not the magic bullet that Reagan’s speech made it seem. Still, there is a chance that some knowledge that would be of great benefit to humanity might not be discovered if research on the subject is suppressed.
Also, this research is very unlikely to produce results in 10 years. Even if someone discovered a way to effectively treat a major disease using stem cells today, the therapy would barely be tested in 10 years. 20 years is possible. I’ve heard of all kinds of promising therapies for cancer, and I’m sure that an equally passionate case could be made for many of them, but even the most promising of them is at least 10 years off, and none are magic bullets.
bizzwire: Such ‘hot’ subjects in science tend to come up fairly often, and I even felt that I might be foolish in pursuing a subject that wasn’t ‘hot’. But studying proteonomics or combinatorial chemistry isn’t like getting a certification in whatever the hottest IT field is. It takes a lot of work and a lot of time, and it’s very difficult to switch to another discipline when you’re completing a postdoc and discover that the market for jobs in your field is saturated with people who thought it would make them rich.
I apologize that my post is perhaps excessively opinion-based. Maybe this thread should be moved – it seems to be mostly a matter of opinion since little purely factual information on the possible benefits of stem cell research exists.
Like most science, there are significant hurdles to overcome. Namely, there is still a lot of fundamental work in actually getting real totipotent (having the potential to become any tissue) cells to grow in culture at all, let alone forever.
Certainly, inroads are made every week. We have had the ability for years to take banked cord blood or bone marrow and use it for total cures of some kinds of leukemia. But getting bone marrow or even “true” stem cells (from the inner cell mass of an embryo) to differentiate into other tissues is riddled with problems. Namely, we would have to replicate the exact milleu of growth factors and cellular contacts, and that is a lot of research down the road.
Saying my opinion could boot this over to GD and I don’t want to do that. Let’s just leave it at this: stem cells have enormous potential, coupled with fewer inherent limitations than other technologies like gene therapy.
I’m a little more optimistic than Roches. It is certainly not a magic bullet now, nor will it be in 5 years. If the money and the incentive is there (without governmental roadblocks), we all will move it as fast as we can. Many biotech innovations have had relatively short turn-arounds from lab breakthrough to clinical application: monoclonal antibody drugs for late stage cancer, oligopeptide engineering for protease inhibitors and antivirals, and recombinant cloned proteins for vaccines and drugs like human growth hormone and insulin. Within 10 to 20 years of discovery, these technologies were in wide-spread use in the clinics. This is what we hope of stem cells.
bizzwire:
I don’t know about the Human Genome Project being touted as the end of disease, but certainly it is an enormously useful tool for geneticists and biologists alike. With completion of other projects like the HapMap project, we are getting huge insights as to the cause of many complex diseases. Proteomics is still a budding field with a lot of room to mature. But none of these have the direct clinical application as stem cells.
There is no way to know yet. It seems to have a promising future, but until it produces, no one can really say.
Well, I’m not entirely pessimistic either. I certainly think it has potential, provided that we don’t expect results too soon. Practically speaking, I think it may have more potential than the Human Genome Project. As celebrated as that achievement may be (and it is significant, from a basic research point of view), relatively few diseases that affect large numbers of people are wholly genetic. Stem cell research can offer hope to people who suffer from diseases that are far more prevalent than any genetic syndrome, such as diabetes and possibly even heart disease.
This is somewhat tangential, but it’s related, and it’s factual. I don’t think Ron Reagan, Jr. stressed the source of embryonic stem cells enough. (The full text of his speech can be found at the New York Times, though it requires registration.) His reference to “undifferentiated cells multiplying in a tissue culture” is scientifically accurate but politically volatile among pro-lifers. It’s important to understand that the source of stem cells for research is likely to be from embryos left over from in vitro fertilization (IVF) attempts. A woman seeking to have a child by IVF may donate, say, 15 eggs to be fertilized in vitro. One viable embryo from this process may be implanted in her uterus and become a fetus, then an infant; the others will be kept in liquid nitrogen. (The first attempt isn’t always successful, but I imagine that some embryos are always left behind.) Several years later, the surplus embryos will be discarded. The embryos that are not implanted are theoretically capable of developing into infants, but they will not. Rather than discarding them, they can be used for basic research. The stem cells that will be used in research are not harvested directly from an embryo, but are cultured in a flask. A similar technique is used with other human tissues – researchers often use cultured cells that are many generations removed from cells that once formed part of a human being. At any rate, it is crucial to emphasize that stem cell research has nothing to do with abortion. The cells being used do not come from aborted embryos, but rather from the leftover fertilized ova of a woman who has chosen to have a child by IVF.
I don’t think there are any magic bullets.
Having said that, it seems hard for me to believe that stem cells will not have some future role to play in medicine.
What we can do now (I’ve done some of this myself) is grow them, manipulate them genetically, differentiate them into various types (neurons, cardiac myocytes, hepatocytes, and all kinds of other things), and implant them.
Getting stem cells, or the progeny of stem cells, to go right where we want, stay alive, and do just what we want has proven to be an enormously difficult task. The initial hopes that one could simply introduce totipotent or pleuripotent cells into sites of injury and regenerate healthy tissue without much manipulation have been dashed almost completely. We know now that approach can yield all kinds of unwanted results, like a taratoma (in the case of ES cells); and often the grafted cells simply die because they fail to integrate properly, and hence self-destruct. Some of the most troubling disappointments recently have been in the area of cardiovascular research; most notably relating to the research of Piero Anversa’s group, which claimed to see functional regeneration of myocardium following infarct using autologous hematopoietic stem-cell grafts in animal models. Several other well-respected groups have not been able to replicate such results (two articles and a rather stinging editorial were just published on the subject in the journal Nature), and have questioned the finding that stem cells derived from bone marrow can differentiate into cardiac muscle. Rather, it appears some of the grafted stem cells may fuse with remaining muscle cells in the myocardium. This may still provide some functional improvement, but the phenomena falls far short of the promise of rebuilding lost tissue good as new by replacing lost cells with new ones of the desired type. We’re just not there yet.
But again, with more time and research, I think a combined approach of stem cells, plus some genetic manipulation of those cells to make it somehow easier for them to incorporate post-grafting, will be the way of the future. We’ll also develop better techniques to differentiate stem cells in vitro, and to provide them with various kinds of scaffolding, to perhaps engineer replacement organs, or parts of organs, which can then be grafted to treat conditions like diabetes or liver disease.
As is true of all tissue grafts, if the cells are not derived somehow from the patient, they will almost certainly lead to graft-versus-host disease and graft failure. So, for instance, ES cells hold the promise of being more versitile than, say, mesenchymal stem cells, but rejection is still an issue. Some exciting new research in cloning has shown us that it may be possible to derive ES cells from adult somatic cells by injecting nuclei from those cells into denucleated oocytes, in much the same manner as was used to generate Dolly the sheep. If this proves to be a viable source of stem cells in humans, that could revolutionize the field.
So, there’s lots to look forward too, but many hurdles to get over in the mean time. There will probably be other issues that we haven’t even thought of yet, and we always have to be ready for disappointment. I think, based on what I’ve seen and read, though, that some modest strides in stem cell therapies will probably lead to new clinically-approved treatments in a decade or so, twenty years at the latest. I’m not sure we’re going to be growing new hearts or brains any time in the forseeable future; and we can’t forget our friends in the cybernetics field who are taking a different, perhaps more practical approach to building spare parts.
It’s an interesting future in store, there’s no question. But, like I said, don’t expect many, if any, magic bullets. Such discoveries are few and far between, and never seem as wonderful in retrospect (thinking specifically of antibiotics and drug-resistance) as they do at first blush.