Mysteries Of Stem Cells Explained
Tuesday, March 2, 2010
Where do stem cells come from? And, what can they be used for? We speak to the co-author of the new book, Stem Cells For Dummies.
MAUREEN CAVANAUGH (Host): I'm Maureen Cavanaugh. You're listening to These Days on KPBS. By now, you probably know if you are for or against stem cell research. Very few other medical research questions have become so public or so political. But, even if you know how you'd vote on the issue, do you really know what stem cells are, where they come from or how they work? The director of UC San Diego’s Stem Cell Initiative has just co-written a book that can answer just about anybody's stem cell questions. It’s called "Stem Cells For Dummies," part of that great ‘For Dummies’ line of easy-to-read instruction books. I’d like to welcome Dr. Larry Goldstein, Professor of Cellular and Molecular Medicine at UC San Diego School of Medicine, Director of UC San Diego Stem Cell program, as well as Investigator at the Howard Hughes Medical Institute. Dr. Goldstein, thanks for coming in.
DR. LARRY GOLDSTEIN (Author “Stem Cells for Dummies): Well, thank you for inviting me.
CAVANAUGH: And we’d like to invite our listeners to join the conversation. In all the talk about stem cells, is there something you just don’t understand? Do you have questions about when we can expect big medical breakthroughs from stem cell research? Call us with your questions and comments, 1-888-895-5727, that’s 1-888-895-KPBS. Dr. Goldstein, how can something as complex as stem cells become, as I say, one of these easy-to-read instruction books?
DR. GOLDSTEIN: Well, so, ultimately, the concepts and the ideas are not that hard if they’re explained in plain English. I think where sometimes scientists fail in communicating with the public is we’re very susceptible to using jargon and the jargon is, ultimately is as though we’re speaking in a different language, Spanish or French. So if I tried to explain a complicated idea to you in Spanish, you’d have – well, maybe you speak Spanish, I don’t know.
CAVANAUGH: I do not.
DR. GOLDSTEIN: Okay, so you’d have a hard time. But if I translate it into English and use terms and words that people understand, the concepts and the ideas, which of course are the most important thing, really, I think, can be gotten across, and that’s what Meg Schneider and I set out to do in this book.
CAVANAUGH: Who is your co-author, Meg Schneider. I wonder, Doctor, did you have to be sort of convinced to do this book?
DR. GOLDSTEIN: Well, I had mixed feelings at first…
DR. GOLDSTEIN: …when a literary agent approached me about this project and so I consulted a couple of my scientific friends and some folks who worry about things like image and reputation and stuff like that and they all said, do it, it’d be…
DR. GOLDSTEIN: …a great thing to do. And so, you know, with that advice and my general belief that making scientific information accessible to people who are not scientists is a really important part of what we, as scientists, must do. Then it was a no-brainer.
CAVANAUGH: What kind of information is in “Stem Cells for Dummies?”
DR. GOLDSTEIN: Wow. Well, we tried to include a little bit of everything so we included both basic concepts in cell biology, what cells are, how they work, how they talk to each other. We included some of the history of stem cell science, which I actually didn’t know much about until we wrote this book, so I went and read about it. There’s some very interesting ideas and concepts that go back a long way. And then, of course, we touched upon the different types of stem cells, how they might be used, where are we now. And then we also wrote sections on the ethics, the policy, the law, as well as myths you should not believe.
CAVANAUGH: That sounds fascinating, though, the history of stem cell science. Were people speculating on the possibility of these cells before they were even discovered?
DR. GOLDSTEIN: Well, that’s right. So in the 1800s, there were ideas floating around about the existence of such cells and there were debates and some scientific attempts to understand whether they really existed or not. But, in fact, the notion of regeneration, which is really what stem cells are all about, is regenerating pieces of tissue or organs, in a sense that goes back to the Greeks. So if you think about the myth of Prometheus, Prometheus got in trouble with Zeus and his fate was to be chained to a rock where an eagle ate his liver every day and then overnight it would regenerate and then the – it suggests that in some way the Greeks had some ideas about the capacity of organs or tissues to regenerate under some circumstances. And, of course, you see that yourself. When you’re cut, your skin grows back. And so those kinds of examples are all around us and they permeate the science of this – sorry, the history of the science of this area.
CAVANAUGH: I’m wondering, what are some of the basic biological things that people might want to brush up on in this book that might help them better understand stem cells?
DR. GOLDSTEIN: Yeah, so there’s a couple of key ideas, I think. One is, our bodies are built out of cells. That’s the basic unit of construction of our tissues. Second, there are many different kinds of cells in our body. They’re different and specialized in the way that small businesses are different and specialized. Pancreatic cells have special products. Nerve cells have a special service; they transmit information while the pancreatic cells make insulin or things like that. And then when those cells die or malfunction, that’s when we have disease. And so the idea is, ultimately, that stem cells give us a way of understanding how those cells work or fail, perhaps give us a way to replace them, and the study of how to do that is built upon decades of what you might call basic research in understanding how cells talk to each other, how they decide who’s going to do what. Am I going to be a hair cell and are you going to be a pancreatic cell or vice versa.
DR. GOLDSTEIN: And so those ideas ultimately are important in understanding how we try to take advantage of this new technology to understand and eventually treat disease.
CAVANAUGH: I’m speaking with Dr. Larry Goldstein and he is the co-author of a new book, “Stem Cells for Dummies.” And we’re taking your calls at 1-888-895-5727. Let’s take a call from Gayle in Alpine. Good morning, Gayle, and welcome to These Days.
GAYLE (Caller, Alpine): Good morning. Thank you. Great program, as usual. Dr. Goldstein, I’ve got a quick question for you. I saw recently on a news program where a dog which was crippled with arthritis, a little eleven-year-old dog, and I believe it was a veterinarian up in North County that’s doing stem cell work, and it showed the dog bouncing around like a three-year-old afterwards. I’m wondering how valid this is and when that’s going to be available for people.
DR. GOLDSTEIN: So that’s a great question, Gayle. So what you’re describing is a kind of therapy or experimental therapy at this point that uses a type of stem cell called a Mesenchymal stem cell. Oh, my God, that’s just a mouthful, isn’t it? But that kind of stem cell, its normal job is to make connective tissue and cartilage and to participate in inflammation sometimes. And so there are experiments being done in animals and just beginning to be discussed in people to try to use these kinds of stem cells to treat arthritis in animals and people. Now my understanding of the data in this area is that it’s pretty early in the game. There’s not a lot of information and so there still needs to be a lot of carefully controlled, what we call double blind where neither the observer nor the patient knows they’ve been treated. I guess in the case of a dog that would be the owner.
DR. GOLDSTEIN: And to really see whether it makes a big difference when you treat in this way. And that’s ultimately what’s needed to say it’s proven, we know it really works as opposed to, well, that dog happened to get better for other reasons. But it’s a very interesting area and I hope more work will be done on it and we’ll see how the data comes out.
CAVANAUGH: Now, Dr. Goldstein, you were telling us – you were giving us some basic biology about where – you know, that we’re made up of different cells and these cells have different jobs to do so where do stem cells come from?
DR. GOLDSTEIN: Wow. Okay, so, first of all, there are many different types of stem cells so all of the cells in you, Maureen, of course, come from that very first cell in development, the zygote, when the sperm cell and the egg cell fused, then that’s the origin of all cells in your body. Now you have, as a adult, and you had as a fetus, stem cells in many of your types of tissues and, of course, there are stem cells in cord blood. And collectively those are referred to as adult stem cells, a bit of a misnomer actually, and they all reside, for the most part, in different tissues such as skin, bone marrow, brain, liver, what have you. And their job throughout life is to replenish cells lost by wear and tear or in some cases in disease. They tend to be relatively restricted in their abilities and are sometimes very hard to find…
DR. GOLDSTEIN: …although we know they’re in there.
DR. GOLDSTEIN: And then there’s another class of stem cells that come from the early embryo. This is where the ethical issues become problematic for some people. And these are stem cells that come from frozen human blastocysts or embryos that were made during in vitro fertilization treatments and that are not destined to start pregnancies, where the couple’s decided to stop having children. And stem cells from those embryos are remarkable in that they can grow for very long periods of time in the lab and they will, when you send them the appropriate signals, make any of the cell types that we find in the adult body, and that makes them very useful in a practical sense for trying to regenerate organs, understand disease and what have you.
CAVANAUGH: So if I’m understanding what you’re saying, the adult stem cells, which is a bit of a misnomer, if you have a stem cells – a skin stem cell in an adult, it can possibly be persuaded to make more skin but it’s never going to be part of a brain. And an embryonic stem cell can basically become, in theory, anything you want it to be.
DR. GOLDSTEIN: Yeah, that’s generally correct with the usual caveats that scientists like…
DR. GOLDSTEIN: …I am always make.
DR. GOLDSTEIN: So in the normal course of event, skin stem cells will not make brain cells.
DR. GOLDSTEIN: And there are people who claim they will and that’s not true. Embryonic stem cells do a wonderful job of making brain cells. We do it on a daily basis in my lab. What’s a little tricky is there’s another method that recently was developed called reprogramming where, by some genetic trickery, we can take certain kinds of skin stem cells called fibroblasts – or they’re not really stem cells, sorry. Skin cells called fibroblasts, treat them with viruses carrying genetic elements that turn them back into stem cells that have properties similar to embryonic stem cells. They’re not identical, they’re not really ready for prime time in terms of treatment. They’re probably unsafe and, of course, in human clinical trials and experiments you want safety first. We don’t want to hurt anybody. But they are remarkable for studying certain aspects of human biology. For example, if I took fibroblasts from you, Maureen…
DR. GOLDSTEIN: …and make a stem cell line using this method, what I would’ve done is taken all of your genetic – unique pattern of genetic variation and locked it up in that stem cell line, and then when I made brain cells, well, I’d have Maureen’s brain cells in a dish in front of me that I could study to see why you might or might not respond to different drugs differently or be susceptible to certain kinds of diseases and what have you, so an enormously powerful tool but not yet ready for the kinds of cell therapy that embryonic stem cells are just beginning to reach the first stages of testing for.
CAVANAUGH: I’m speaking with Dr. Larry Goldstein. He’s Professor of Cellular and Molecular Medicine at UC San Diego School of Medicine, and also the co-author of the new book “Stem Cells for Dummies.” We’re taking your phone calls at 1-888-895-5727. Right now Madeleine is calling us from Vista. Good morning Madeleine. Welcome to These Days.
MADELEINE (Caller, Vista): Hi. Thanks for taking my question. As a consumer, a lot of patients, a lot of pregnant women are getting bombarded with cord blood collection from companies who are sprouting out to collect these stem cells and save them in case you need them. I was wondering how you felt about that and when you answer, I just wanted to make sure you don’t have money invested in these companies and if you do, just to disclose that. But how you feel about women donating the cord blood stem cells and saving them? I mean, they’re paying some money for this and what is – what’s available out there with…
DR. GOLDSTEIN: Great. Thank you for your question, Madeleine. That’s really a terrific question. So first of all, I own no stock in cord blood companies. I have not started any cord blood companies, and to my knowledge I have no financial interest in any cord blood companies. In fact, my wife handles all of our money. I have no idea what she does with it. So cord blood banks are a really interesting issue and the issues vary from country to country around the world but I’ll concentrate on the United States. So in the United States there’s two separate systems of cord blood banking, remarkably. There’s a private system where an individual such as yourself would pay to have cord blood from your baby’s cord frozen and stored and you would pay on an on-going basis for storage of that cord blood in case someday your child needed what is effectively a bone marrow transplant because that’s really cord blood’s primary uses at the moment, is for diseases like leukemias and certain kinds of other blood disorders, and it’s very useful in those situations. There are two – So that’s the private bank – banking system. There’s also a publicly funded banking system where you don’t pay to have the cord blood stored; the government pays and – but the cord blood you store is not held in reserve for your child, it’s available to anybody who might need a cord blood transplant and then the recipient pays back the costs of testing and everything else. Now the catch is that when I looked into this with Meg when we were writing this book, the data thus far are that most children are unlikely, you know, somewhere on the order of 1 to 501 to a 1000 or less, likely to need their own cord blood for a transplant because of a disease they developed in childhood. And once people are adults, one cord blood’s worth of stem cells is not enough to treat an adult in general. You need multiple cords. And so it turns out that in this country, although the bulk of the cord blood is stored at the moment in private banks, the bulk of the transplants are done out of the public banks and so what you choose to do, I think, depends upon, you know, your spirit of altruism perhaps and whether you want to protect your child against an unlikely chance of needing a transplant versus contributing perhaps to the common good where you’re likely to have an impact.
CAVANAUGH: That’s fascinating, how many areas that this actually covers.
DR. GOLDSTEIN: It’s remarkable.
CAVANAUGH: Let me ask you, what – since you’ve been doing this book and you’ve been breaking down not only all your knowledge about stem cells but also researching it, what do you think are some of the biggest misconceptions people have about this kind of research?
DR. GOLDSTEIN: Well, there’s a lot of them. One misconception is that embryonic stem cells are taken from aborted fetuses. That’s one that floats around out there and folks like Rush Limbaugh like to say that. It’s just not true. The embryos that are used as the source of embryonic stem cells have never been in a woman’s body; they were generated in a dish in the lab and then they’ve been frozen away to try to start pregnancies when couples can’t have kids the old fashioned way. But sometimes there are extra embryos left over after couples are done having kids and then those can under appropriate circumstances be donated for research and that’s where those stem cells come from. Some people are against that. There are ethical issues on both sides but that’s the cold, hard fact. So that’s one myth. The other myth is perhaps the sense that, well, if we just work on it for a day or two we’re going to have, you know, solved every problem overnight, and that’s also not true. I mean, the fact is that problems in human disease are really hard and so we need to have our smartest scientists and smartest young people going into these fields, we need to be sure that they have adequate support to do their work, and then we need to hang in there while the discoveries are made that will turn this into more than a good idea on a blackboard but will realize the potential and begin delivering. Now, there are many different diseases in areas where this technology can contribute and so, you know, as you look across the board at a lot of different potential applications, some of them are beginning to pick up speed and go more quickly. Some of them are hitting unexpected problems. That’s the nature of scientific research. We don’t know what we’re going to find until we do the experiments. I think the third thing folks need to watch out for is that there are a number of clinics, so-called clinics around the world, that are capitalizing on the press and the notion that there’s a lot of potential in this area of medical research and offering for sometimes substantial amounts of money so-called therapies for which there’s no rigorous scientific evidence that they work. And so you can go to another country and for $50,000 or $100,000 you can be shot up with who knows what kind of cell. I mean, you don’t even always know what’s in the vial. They claim something but since there’s no regulation, that may or may not be true, and they’ll claim to cure every disease known to mankind. And, you know, I think this is something people really need to watch out for because when you hit Google, for example, these sites just pop up right on top of any search for stem cells. And so it’s an area where very substantial caution needs to be exercised.
CAVANAUGH: Let’s take a phone call from Shirley in La Mesa. Good morning, Shirley, and welcome to These Days.
SHIRLEY (Caller, La Mesa): Good morning. I happen to have macular degeneration, the wet kind, and, by the way, when you get to be 65 you have, if you’re male, you’ve got out of four chances, if you’re female it’s one out of three, and it’s a pandemic. Recently, I read an article in the Association for Macular Degeneration (sic) that reported early findings, preliminary findings, on the use of it with macular degeneration. They had 12 subjects, and apparently the treatment was able to stop the progression of it. Whether it would cure it or not, we ascertain it’s too early to know that but I would just like to remind people of that.
CAVANAUGH: Well, thank you for the call, Shirley, and are you aware of stem cell research in macular degeneration, Doctor?
DR. GOLDSTEIN: Oh, absolutely. So there’s a great deal of stem cell research in all the different organs in the body including the eye. There’s a great deal of interest at UCSD as well in trying to understand how stem cells might be used to understand or treat diseases of the eye such as macular degeneration, glaucoma and what have you. It’s in its early stages, as Shirley noted, and so we have to be careful not to extend what happens in a small group of people, 12 people, to what may happen in thousands when you really get it out there. That’s one of the problems, always, in so-called clin – you know, experimental therapies, is that what’s sometimes true in two or three patients does not turn out to be true when you have thousands, for statistical reasons, because disease varies, and, of course, when trials are not double blind, people want to get better and there are placebo effects. But I think, you know, there’s a great deal of really wonderful research to be done. It all looks very promising and, you know, full speed ahead.
CAVANAUGH: I’m going to be kind of like jumping on one of the misconceptions that you were talking about earlier but I wonder, we’ve heard so much about the promise of stem cells and you just finished telling us that disease is a complicated issue. But I wonder, are there some things that stem cells are being used for in human beings right now to treat disease?
DR. GOLDSTEIN: Absolutely. So one of the best current treatments for leukemia when drug treatments fail is a bone marrow transplant and that is effectively a stem cell transplant. Now the history of bone marrow transplant gives you an idea of the kinds of problems we’re going to need to solve for some of the other organs and diseases. So blood-forming stem cells were first found in the fifties and sixties and then it took 10 or 20 years to do the experiments to figure out how to turn that into a safe and effective therapy. It still has risks as all therapies do. It’s a pretty rough treatment but it’s one where the risk benefit analysis is, by and large, that this is really worth doing. There are many treatments being tested for sickle cell, multiple sclerosis, type I diabetes, what have you, using different kinds of stem cells and using so-called blood forming stem cells as possible treatments for some of these disorders. They’re experimental. And it takes time to go from, as I said, something that works in a small number of people to something where we have enough confidence as a society that if we treat large numbers of people that there aren’t going to be any unexpected problems and that the therapies really are worthwhile. It’s a hard kind of thing because, of course, we’re surrounded by friends and family members who have terrible diseases in many cases that we want to treat today, not tomorrow and not the day after tomorrow. And yet, from a social perspective or even from an individual perspective, we don’t want to make people worse by treating them with something that we’re not quite sure about yet. And that’s why we have clinical trials, that’s why we have stringent regulation. There’s always a tug of war between let’s go faster and take more risks versus we want to be sure that nobody is harmed and that’s a very hard problem, of course, but it’s one that we have to traverse.
CAVANAUGH: I’m wondering, you mentioned the ethical and political objections that people have raised to the use of embryonic stem cells. Has, with the new administration, has the political climate changed for stem cell research?
DR. GOLDSTEIN: In part. It’s still complicated, unfortunately. And partly there was a misconception about the Bush administration policy, and I think the Bush administration got a little bit of a bad rap on this. So when President Bush first generated a policy that said that federal funding could be used for embryonic stem cell research, that was a great day. I mean, that was a big step forward and for the first time you could do this research with stem cell lines that had been taken from embryos prior to the date on which he announced his policy. So it was a really good policy on that day but then over time, as more lines were generated with better methods that were not eligible under the Bush policy, the policy showed its age. Now the Obama policy does not have, in a sense, a date certain before which cell lines must have been generated, so that’s a real improvement. What’s a little tricky about it is that the ethical guidelines in the Bush administration policy for how embryos would be donated or must have been donated to research were actually rather lax, and the Obama administration policies are actually quite a bit more stringent. And so we’re going through a transition period where, so far, some of the lines that were eligible under the Bush policy are not eligible under the Obama policy but at least there’s no limit on the dates and so future derivations or future generation of cell lines can be done with the highest possible ethical standards for being sure that donors are appropriately informed, that there’s no coercion, pressure, what have you.
CAVANAUGH: Well, I can certainly see why you were chosen to make complex issues easy for people to understand.
DR. GOLDSTEIN: Thank you.
CAVANAUGH: Thank you so much for speaking with us today. I want…
DR. GOLDSTEIN: Thank you for having me.
CAVANAUGH: Dr. Larry Goldstein is Professor of Cellular and Molecular Medicine at UC San Diego School of Medicine. He’s the Director of UC San Diego Stem Cell Program, and he is also the co-author of the new book, “Stem Cells for Dummies.” And Dr. Goldstein will be discussing and signing copies of “Stem Cells for Dummies” tonight at seven at The Book Works in Del Mar. If you’d like to comment, please go online, KPBS.org/thesedays. And stay with us for hour two of These Days right here on KPBS.