Experts discuss stem cell treatments for cancer, neurosurgery, orthopedics, pediatrics
The use of stem cells in medical treatments already is yielding exciting results and may yield greater medical advances in the future. At a recent event hosted by Rush University Medical Center, experts at Rush discussed the role of stem cells in neurosurgery, orthopedics, pediatrics and oncology and how their breakthrough research may dramatically improve the lives of people afflicted by disease and severe injury. An edited transcript of that discussion appears below.
Larry Goodman, MD, CEO of Rush University Medical Center and the Rush system, moderated the conversation. The panelists included Brian Cole, MD, MBA, professor in the Department of Orthopedic Surgery and section head of the Center for Cartilage Restoration at Rush; Richard G. Fessler, MD, PhD, professor in the Department of Neurological Surgery; Timothy M. Kuzel, MD, chief of the Division of Hematology, Oncology and Cell Therapy; and Anna Spagnoli, MD, the Woman’s Board Chair of the Department of Pediatrics.
Larry Goodman: First let me spend one minute or so on stem cells. They’re a big part of regenerative medicine with a lot of potential. They’re cells that can literally divide into other types of cells in the body. The idea to have a cell that possibly divides into either a liver cell, or a pancreas cell, or a spinal cord cell when you most need it is pretty exciting.
That said, I’ve asked each of the panelists to spend a few minutes summarizing either their research or the way they use stem cells in regenerative medicine in their area.
Timothy Kuzel: We’ve been basically using stem cells for 40 years, and when we first started, we actually didn’t know those were stem cells. We harvested bone marrow from a donor, re-infused it in the recipient, and the idea was to regenerate the bone marrow and protect the patient from the lethal effects of high doses of chemotherapy and radiation for their cancer.
We naively assumed that it was the chemo and the radiation that were actually curing patients with a bone marrow transplant for acute leukemia. It took us about 20 years to begin to understand what a stem cell was. We began to collect stem cells without even bone marrow harvest, which was good.
But we learned something even more important. We learned that it was regenerating the immune system of the patient that actually allowed the cancer to be treated. That’s permitted us to greatly reduce the chemotherapy and the radiation doses we give to patients. Now we give just enough to allow those stem cells to move into the host, grow and flourish and develop and attack the immune system.
Now, that’s all well and good. We treat leukemia and lymphoma patients that way even today. But the field has embraced the whole idea of immunotherapy now. Nowadays we talk about regenerating the immune system in patients to recognize cancers as really foreign tissue and to attack them.
We can do that without stem cells. We can do that just recruiting and regenerating the patient’s own immune system. So a lot of the fundamental advances in stem cell, bone marrow transplant, stem cell transplant, have really led to us being able to really treat all kinds of cancers now.
Brian Cole: I’m an orthopedic surgeon, but the reality is probably 80 to 90 percent of my day is spent doing non-surgical things. The things that I’m mostly interested in are dealing with problems with tendons, ligaments, cartilage, and things of that matter. Inherently all of us actually have stem cells in our bodies that we can recruit.
In fact, some of the treatments we use in the area of repairing cartilage utilize cells that we can recruit. For example, in the knee, by just poking small holes in the bone we recruit those stem cells, some of the bone marrow stem cells that Dr. Kuzel just was talking about.
Our interests are now in the area of osteoarthritis. Osteoarthritis is obviously a very common disease. The way that we use stem cells for it are to sort of take advantage of them as almost like little pharmacies that have growth factors and very important proteins that can either act independently or recruit your own body’s stem cells into the area to treat the symptoms of arthritis.
These are ways to reduce symptoms. We’re not to the point where we can regenerate an entire joint or take an individual who is slated to have a joint replacement and prevent them from needing that replacement. But what we can do are treat symptoms in an office setting that are otherwise untreatable. Mostly what I do is to reduce pain and improve function, and do that long enough that it makes sense.
The other area of interest is in helping rotator cuff repairs to stay healed, and much of our existing efforts are in what’s known as biologic surgery. We aim to optimize the outcomes of surgeries by helping the body to heal more predictably.
Anna Spagnoli: I am a pediatrician, and I have been taking care for many years of children with genetic bone diseases like osteogenesis imperfecta that cause the bones to be brittle. These are children that can have many fractures in their lives, and we still don’t have a treatment for them.
The exciting thing that is happening with my research program is that we have discovered that stem cells can actively regenerate fractured bones. Our findings can help those children, as well patients that fail bone fracture healing. Twenty percent of the patients that fracture do not heal. So that’s 600,000 people in the U.S. that do not heal.
We discovered ways to make stem cells to become “smart stem cells” and improve fracture repair. Stem cells are present in many places of the body. Our research has led to the discovery of ways to direct those cells to the place where they are needed, and to repair the part of the body that is damaged, in the case of our patients with a fractured bone. What we discovered is that, yes the bones have stem cells, but they need special factors to actually be used be recruited within a fracture and to become bone cells.
One of these factors is called AMD3100. It’s a drug already in clinical practice and used to treat patients that receive bone marrow transplant. We found that if we combine stem cells with this drug, the cells are directed toward the fracture where they regenerate the bone. We are now looking at clinical trials to combine a patient’s own stem cells, so called autologous stem cells, with AMD3100 to treat patients that fail fracture repair.
Our lab has also discovered that joints have stem cells. This is an important discovery. The observation that joints are not able to heal had led scientists to wrongly believe that joints did not have stem cells.
What we found was that the stem cells are not only present in the joints, but they actually make anti-inflammatory factors. Therefore, in patients with osteoarthritis stem cells can be useful not only to repair the joints but also to decrease the inflammation and to control the pain.
Richard Fessler: I have been treating patients with spinal cord injury for 30 years, and I’ve done research in this area of spinal cord injury for about 20 years. We have known about spinal cord injuries since 5000 years ago. The treatment at that time was to not treat them, to let them die. In the succeeding 5000 years, we have made essentially no progress.
So about a year and a half ago, the FDA approved us to do transplantation into patients who are paralyzed in the neck. Now that’s a big deal. These cells only have to grow a centimeter or two, and we can return one level of function.
In our study we just recently released the 12-month results of patients who receive 10 million cells injected into their spinal cord. Of these patients, 100 percent got one level back. 60 percent got two levels back, and one patient got three levels back.
For the first time in recorded history, we have made progress in reversing spinal cord injury. We haven’t cured it. It’s like cancer. Fifty years ago, cancer was a death sentence. Now, many are curable. There was a period in between there where they weren’t quite curable but they were partially treatable.
I think we’ve made that step in spinal cord injury. It’s not curable, it’s now partially treatable.
Goodman: I obviously have a lot more questions for these panelists, but I thought we would do is open this up to all of you.
Audience member: Do younger people respond better than older people for this kind of stuff, regeneration?
Fessler: Our next study will be a randomized study, and we hope to be able to do them in younger patients. Kids get better, adults not so much. Spinal cord injury happens to young people. It’s young male injuries it happens to most. If I could do 14-year-olds, 16-year-olds, those are the people that really have a chance to do better. So I hope we can go that way.
Goodman: Osteogenesis imperfecta is a younger person’s problem, isn’t it?
Spagnoli: Yes, osteogenesis imperfecta affects children. The reason why osteogenesis imperfecta is treatable with stem cells is that even if stem cells would make a partial replacement of the bad protein that the bones of those patients make, it would be enough to prevent them from fracturing.
Osteogenesis imperfecta was one of the first diseases in which stem cells were tried. In patients treated with stem cells, we proved that they were able to make the correct protein and patients showed some promising improvements. What we need to learn is actually how to modify the stem cells so that they stay within the bones and they last for the life of the patients.
Audience member: In light of the past controversy regarding the use of stem cells, what is the current political status of using stem cells in research?
Fessler: We can only do stem cell lines that were approved in 1996. There were eight stem cell lines. It turns out, the one we’re using is a good one. But we would like to create other stem cell lines.
Socially it will become less of an issue, because we’re learning the techniques to take cells and regress them to a primitive state and then regrow them into what we want. Once that’s done, our access to stem cells will be much easier.
Audience member: There are some small clinics offering treatment with stem cells, especially for knee injuries. In your opinion, how credible are those people?
Cole: It’s an area of concern, and it’s one of the things that we take very seriously, because the barrier to entry is very low when it comes to the use of something called a stem cell in orthopedics. The United States has the largest stem cell tourism industry in the world right now. It’s not particularly regulated, although over the next year that may change.
The FDA is clearly cracking down, because every one of these technologies has no label for the use of arthritis, no clinical proof that it can do formal regeneration or stave off the knee for knee replacement and regenerate the joint. I always tell people, it’s really buyer beware.
Spagnoli: It’s a very important question because for the investigators that are doing stem cell research. We are very worried that patients receiving stem cells in uncontrolled and unregulated places can be harmed, and this will not only have an effect on the patient but may stop the research on stem cells. This is the reason that we are seeking regulations for stem cell research and to have controlled clinical trials.
Fessler: General rule of thumb, if they’re asking for cash, be very wary.
Audience member: What is the impact on stem cell research on longevity? Are people being treated living longer than normal?
Kuzel: I think there’s no doubt that the longevity of the individual patient who gets a bone marrow transplant or who gets cellular therapy, for example a child with refractory ALL treated with some of our new cell therapies, find their longevity is greatly improved because they’re cured of a horrible malignancy.
But for the healthy person, probably stem cells aren’t the issue for a healthy person. You’ve got other programmed pathways in your body. Learning how to turn them off is probably more important than giving stem cells.
Goodman: Let me take this opportunity to thank our panel. We really appreciate the great job they did tonight. As you think about what we’ve talked about tonight, there are a couple of other areas to just remember about.
Right now, there are not enough transplants for the people who need them. If you can figure out a way to make islet cells of the pancreas work and be reenergized to make insulin, suddenly diabetes could go away without a pancreatic transplant or without insulin. Liver transplants, all those things could be a target for this kind of therapy.
Parkinson’s disease is a neurological disease that is a problem in a very small part of the brain. They just are not making dopamine anymore. If you can figure out a way to reactivate whatever stem cells might be there, get that going again, suddenly not only don’t you need L-dopa, but the problem with most of the anti-Parkinson’s disease drugs is they kind of wear out after about a decade or so. Then you’re on second line and third line drugs.
None of that might be needed if stem cell research actually works the way the promise is. Tonight you heard about examples of it already working, and our hope is we’re back again in five or ten years with some patients that have really been remarkably changed by this research.