Stories of Hope: Spinal Cord Injury

This week on The Stem Cellar we feature some of our most inspiring patients and patient advocates as they share, in their own words, their Stories of Hope.

Katie Sharify had six days to decide: would she let her broken body become experimental territory for a revolutionary new approach—even if it was unlikely to do her any good? The question was barely fathomable. She had only just regained consciousness. A week earlier, she had been in a car crash that damaged her spine, leaving her with no sensation from the chest down. In the confusion and emotion of those first few days, the family thought that the treatment would fix Katie’s mangled spinal cord. But that was never the goal. The objective, in fact, was simply to test the safety of the treatment. The misunderstanding – a cure, and then no cure — plunged the 23-year-old from hope to despair. And yet she couldn’t let the idea of this experimental approach go.

Katie never gave up hope that stem cell-based therapies could help her or others like her living with spinal cord injury.

Katie never gave up hope that stem cell-based therapies could help her or others like her living with spinal cord injury.

Just days after learning that she would never walk again, that she would never know when her bladder was full, that she would not feel it if she broke her ankle, she was thinking about the next girl who might lie in this bed with a spinal injury. If Katie walked away from this experimental approach—what would happen to others that came after her?

Her medical team provided a crash course in stem cell therapy to help Katie think things through. In this case the team had taken stem cells obtained from a five-day old embryo and converted them into cells that support communication between the brain and body. Those cells would be transplanted into the injured spines. Earlier experiments in animal models suggested that, once in place, these cells might help regenerate a patient’s own nerve tissue. But before scientists could do the experiment, they needed to make sure the technique they were using was safe by using a small number of cells, too few to likely have any benefit. And that’s why they wanted Katie’s help in this CIRM-funded trial. They explained the risks. They explained that she was unlikely to derive any benefit. They explained that she was just a step along the way. Even so, Katie agreed. She became the fifth patient in what’s called a Phase I trial: part of the long, arduous process required to bring new therapies to patients. Shortly after she was treated the trial stopped enrolling patients for financial reasons.

That was nearly three years ago. Since then, she has been through an intensive physical therapy program to increase her strength. She went back to college. She tried skiing and surfing. She learned how to make life work in this new body. But as she rebuilt her life she wondered if taking part in the clinical trial had truly made a difference.

“I was frustrated at first. I felt hopeless. Why did I even do this? Why did I even bother?” But soon she began to see how small advances were moving the science forward. She learned the steep challenges that await new therapies. Then this year, she discovered that the research she participated in was deemed to be safe and is about to enter its next phase, thanks to a $14.3 million grant from CIRM to Asterias Biotherapeutics. “This has been my wish from day one,” Katie says.

“It gives me so much hope to know there is an organization that cares and wants to push these therapies forward, that wants to find a cure or a treatment,” she says. “I don’t know what I would do if I thought nobody cared, nobody wanted to take any risks, nobody wanted to put any funding into spinal cord injuries.

“I really have to have some ray of hope to hold onto, and for me, CIRM is that ray of hope.”

For more information about CIRM-funded spinal cord injury research, visit our Spinal Cord Injury Fact Sheet. You can read more about Katie’s Story of Hope on our website.

CIRM-Funded Scientists Test Recipe for Building New Muscles

When muscles get damaged due to disease or injury, the body activates its reserves—muscle stem cells that head to the injury site and mature into fully functioning muscle cells. But when the reserves are all used up, things get tricky.

Scientists at Sanford-Burnham may have uncovered the key to muscle repair.

Scientists at Sanford-Burnham may have uncovered the key to muscle repair.

This is especially the case for people living with muscle diseases, such as muscular dystrophy, in which the muscle degrades at a far faster rate than average and the body’s reserve stem cell supply becomes exhausted. With no more supply from which to draw new muscle cells, the muscles degrade further, resulting in the disease’s debilitating symptoms, such as progressive difficulty walking, running or speaking.

So, scientists have long tried to find a way to replenish the dwindling supply of muscle stem cells (called ‘satellite cells’), thus slowing—or even halting—muscle decay.

And now, researchers at the Sanford-Burnham Medical Research Institute have found a way to tweak the normal cycle, and boost the production of muscle cells even when supplies appear to be diminished. These findings, reported in the latest issue of Nature Medicine, offer an alternative treatment for the millions of people suffering not only from muscular dystrophy, but also other diseases that result in muscle decay—such as some forms of cancer and age-related diseases.

In this study, Sanford-Burnham researchers found that introducing a particular protein, called a STAT3 inhibitor, into the cycle of muscle-cell regeneration could boost the production of muscle cells—even after multiple rounds of repair that would otherwise render regeneration virtually impossible.

The STAT3 inhibitor, as its name suggests, works by ‘inhibiting,’ or effectively neutralizing, another protein called STAT3. Normally, STAT3 gets switched on in response to muscle injury, setting in motion a series of steps that replenishes muscle cells.

In experiments first in animal models of muscular dystrophy—and next in human cells in a petri dish—the team decided to modify how STAT3 functions. Instead of keeping STAT3 active, as would normally occur, the team introduced the STAT3 inhibitor at specific times during the muscle regeneration process. And in so doing, noticed a significant boost in muscle cell production. As Dr. Alessandra Sacco, the study’s senior author, stated in a news release:

“We’ve discovered that by timing the inhibition of STAT3—like an ‘on/off’ light switch—we can transiently expand the satellite cell population followed by their differentiation into mature cells.”

This approach to spurring muscle regeneration, which was funded in part by a CIRM training grant, is not only innovative, but offers new hope to a disease for which treatments have offered little. As Dr. Vittorio Sartorelli, deputy scientific director of the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), stated:

“Currently, there is no cure to stop or reverse any form of muscle-wasting disorders—only medication and therapy that can slow the process. A treatment approach consisting of cyclic bursts of STAT3 inhibitors could potentially restore muscle mass and function in patients, and this would be a very significant breakthrough.”

Sacco and her colleagues are encouraged by these results, and plan to explore their findings in greater detail—hopefully moving towards clinical trials:

“Our next step is to see how long we can extend the cycling pattern, and test some of the STAT3 inhibitors currently in clinical trials for other indications such as cancer, as this could accelerate testing in humans.”

FDA gives Asterias green light to start CIRM-funded clinical trial in spinal cord injury

This morning Asterias Biotherapeutics announced that they have been cleared by the Food and Drug Administration (FDA) to start a clinical trial using stem cells to treat spinal cord injury. It’s great news, doubly so as we are funding that trial.

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You can read more about the trial in a news release we just sent out.

This trial is a follow-on to the Geron trial that we funded back in 2010 that was halted after 5 patients, not because of any safety concerns but because of a change in Geron’s business strategy.

Katie Sharify was the fifth and final patient enrolled in that trial and treated with the stem cells. Like all of us she was disappointed when the trial was halted. And like all of us she is delighted that Asterias is now taking that work and building on it.

Here’s what Katie had to say when she heard the news:

“Of course, I’m very happy that the trial has been revived. Knowing that the FDA approved the continuation based on the safety data I was a part of is great news. As you know, the trial was halted 2 days before I received the stem cells. A big part of why I ended up participating was because I figured that once the study is revived a bigger sample size (even if just by 1 person) was more valuable than a smaller one. I never regretted my choice to participate but I have doubted whether my contribution actually meant anything. I think now I finally feel a sense of accomplishment because the trial is not only being continued but also progressing in the right direction as a higher dose is going to be used. A lot remains unknown about human embryonic stem cells and that’s exactly why this research is so important. The scientific community is going to have a much greater understanding of these stem cells from the data that will be collected throughout the study and I’m glad to have been a part of this advancement.”

Stem Cell Stories that Caught our Eye: “Let it Grow” Goes Viral, Stroke Pilot Study, The Bowels of Human Stem Cells, Tumor ‘Safety Lock.’

Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.

“Let it Grow” Goes Viral (and National!): Last week on The Stem Cellar we shared one of our favorite student videos from our annual Creativity Program. The video, a parody of the hit song from the movie Frozen, highlighted the outstanding creativity of a group of high school students from City of Hope in Los Angeles. And now, the song has made a splash nationwide—with coverage from ABC 7 Bay Area and even NBC New York!

Students from the City of Hope practice their routine for the group video

Students from the City of Hope practice their routine for the group video

Watch the full video on our YouTube page.

Stroke Pilot Study Shows Promise. Researchers at Imperial College London are currently testing whether stem cells extracted from a patient’s bone marrow can reverse the after effects of a stroke.

Reporting in this week’s Stem Cells Translational Medicine the team, lead by Dr. Soma Banjeree, describe their pilot study in which they collect a type of bone marrow stem cells called CD34+ cells. These cells can give rise to cells that make up the blood and the blood vessel lining. Earlier research suggested that treating stroke victims with these cells can improve recovery after a stroke—not because they replace the brain cells lost during a stroke, but because they release a chemical that triggers brain cells to grow. So the team decided to take the next step with a pilot study of five individuals.

As reported in a recent news release, this initial pilot study was only designed to test the safety of the procedure. But in a surprising twist, all patients in the study also showed significant improvement over a period of six months post-treatment. Even more astonishing, three of the patients (who had suffered one of the most severe forms of stroke) were living assistance-free. But since the first six months after injury is a time when many patients see improved function, these results need to be tested in a controlled trial where not all patients receive the cells

Immediate next steps include using advancing imaging techniques to more closely monitor what exactly happens in the brain after the patients are treated.

Want to learn more about using stem cells to treat stroke? Check out our Stroke Fact Sheet.

Deep in the Bowels of Stem Cell Behavior. Another research advance from UK scientists—this time at Queen Mary University of London researchers—announces important new insight into the behavior of adult stem cells that reside in the human gastro-intestinal tract (which includes the stomach and intestines). As described in a news release, this study, which examined the stem cells in the bowels of healthy individuals, as well as cells from early-stage tumors, points to key differences in their behaviors. The results, published this week in the journal Cell Reports, point to a potential link between stem cell behavior and the development of some forms of cancer.

By measuring the timing and frequency of mutations as they occur over time in aging stem cells, the research team, led by senior author Dr. Trevor Graham, found a key difference in stem cell behaviors between healthy individuals, and those with tumors.

In the healthy bowel, there is a relative stasis in the number of stem cells at any given time. But in cancer, that delicate balance—called a ‘stem cell niche’—appears to get thrown out of whack. There appears to be an increased number of cells, paired with more intense competition. And while these results are preliminary, they mark the first time this complex stem cell behavior has been studied in humans. According to Graham:

“Unearthing how stem cells behave within the human bowel is a big step forward for stem cell research. We now want to use the methods developed in this study to understand how stem cells behave inside bowel cancer, so we can increase our understanding of how bowel cancer grows. This will hopefully shed more light on how we can prevent bowel cancer—the fourth most common cancer in the UK.”

Finding the ‘Safety Lock’ Against Tumor Growth. It’s one of the greatest risks when transplanting stem cells: the possibility that the transplanted cells will grow out of control and form tumors.

But now, scientists from Keio University School of Medicine in Japan have devised an ingenious method that could negate this risk.

Reporting in the latest issue of Cell Transplantation and summarized in a news release, Dr. Masaya Nakamura and his team describe how they transplanted stem cells into the spinal columns of laboratory mice.

And here’s where they switched things up. During the transplantation itself, all mice were receiving immunosuppressant drugs. But then they halted the immunosuppressants in half the mice post-transplantation.

Withdrawing the drugs post-transplantation, according to the team’s findings, had the interesting effect of eliminating the tumor risk, as compared to the group who remained on the drugs. Confirmed with bioluminescent imaging that tracked the implanted cells in both sets of mice, these findings suggest that it in fact may be possible to finely tweak the body’s immune response after stem-cell transplantation.

Want to learn more about stem cells and tumor risk? Check out this recent video from CIRM Grantee Dr. Paul Knoepfler: Paul Knoepfler Talks About the Tendency of Embryonic Stem Cells to Form Tumors.

Grafted Stem Cells Snake through Spinal Cord, CIRM-Funded Study Finds

New research lends increasing support to the notion that paralysis may not be so permanent after all.

Scientists at the University of California, San Diego have generated stem cells that, when grafted onto the injured spines of rats—traverse through the injury sites, coupling with nerve cells hidden beneath the damaged tissue. These results, published today in the journal Neuron, are a critical next step towards using stem cell-technology to reverse spinal cord injury—a condition that has long been considered irreversible.

The extension of human axons into host adult rat white matter and gray matter three months after spinal cord injury. [Credit: UCSD School of Medicine

The extension of human axons into host adult rat white matter and gray matter three months after spinal cord injury. [Credit: UCSD School of Medicine]

This research team, led by CIRM grantee Dr. Mark Tuszynski, generated stem cells from the skin cells of an adult human male. These so-called induced pluripotent stem cells, or iPS cells, then had the ability to transform into virtually any cell type. With a bit of coaxing, the team transformed them one more time—into early-stage neurons—and grafted them onto the injured rats. After monitoring the animals over a period of three months, what they began to see astonished them.

The most amazing changes came from the cells’ axons—long, spindly projections that connect neurons to each other, allowing them to communicate through transmission of electrical signals. Much to their surprise, the team saw these iPS cell-derived axons began to grow—some extending across the animals’ entire central nervous system.

But it wasn’t just the fact that the axons grew that excited researchers—it’s where they went. They began to pierce through the spinal injury sites, penetrating scar tissue and grey matter and forming connections with existing rat neurons that had been entombed inside. Even more incredibly, the native rat axons began to do the same—growing and piercing through the iPS cell grafts to form connections of their own.

As Tuszynski explained in a news release:

“These findings indicate that intrinsic neuron mechanisms readily overcome the barriers created by a spinal cord injury to extend many axons over very long distances, and that these capabilities persist even in neurons that have been reprogrammed.”

The results of this study are encouraging, say the research team, though they do raise a few questions about the underlying signaling mechanisms that are guiding these axons to grow and become intertwined. Tuszynski elaborated:

“The enormous outgrowth of axons to many regions of the spinal cord and even deeply into the brain raises questions of possible side effects if axons are mis-targeted. We also need to learn if the new connections formed by axons are stable over time, and if implanted human neural stem cells are maturing on a human time frame—months to years—or more rapidly.”

The researchers are now exploring whether using different types of stem cells, such as embryonic stem cells, would yield similar results. Once they hone in on the best method, they hope to take their findings further down the path towards clinical trials.

“Ninety-five percent of human clinical trials fail,” explained Tuszynski. “We want to determine as best we can the optimal cell type and best method for human translation so that we can move ahead rationally and, with some luck, successfully.”

Stem cell stories that caught our eye: better cell reprogramming, heart failure and false claims for stem cells

Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.

Improving the efficiency of creating stem cell lines.
Ever since researchers first learned to reprogram adult cells to behave like embryonic stem cells in 2007 teams have tried to do it better. The earliest reprogramming resulted in less than one percent of cells converting to the stem cell state. Many years and many reprogramming recipes later some teams have got that up to a few percent, but usually still in the single digits. CIRM-funded researchers at the University of California, San Francisco, have uncovered a path that could yield dramatic increases in efficiency in creating these stem cells. They stepped back to look at what genetic factors were acting as brakes on the reprogramming and have now mapped out multiple brake points that could be inhibited to improve the production of stem cells. HealthCanal ran the university’s press release based on the journal publication in Cell.

Does source of adult cells matter for iPS-type stem cells. When researchers turn adult tissue into embryonic-like iPS cells, they know that the reprogrammed stem cells retain some memory of the type of adult tissue they were, whether it was skin, brain or heart. So, a CIRM-funded team at Stanford set out to do a series of experiments to see if that mattered. They created iPS cells from heart tissue and from skin cells. And initially, there was a difference. The stem cells made from heart more readily matured into heart muscle than those from skin, but over time, as the cells grew in the lab the difference abated. Both types of cells began to function like normal heart muscle. Stanford’s Scope blog wrote about this and a companion paper that were published this week in the Journal of the American College of Cardiology.

Heart progenitor cells, the middlemen between stem cells and adult heart muscle, shown here in green and infected with coxsackie vurus.

Heart progenitor cells, the middlemen between stem cells and adult heart muscle, shown here in green and infected with coxsackie vurus.


Viral heart failure link may be via stem cells
. Our hearts are one of our poorest performing organs when it comes to repairing themselves. The liver does it well. The lining of our guts does it well—the heart not so much. Scientists generally attribute this to the very small number of stem cells we retain in our hearts. If you lose those few, you are in deep trouble. While there are many reasons for heart failure, we have known that a high percent of those who develop this weakening of the heart’s ability to pump blood have signs of having been infected with the coxsackie virus. Researchers at San Diego State University have found out a possible reason why. The virus appears to selectively seek out and destroy the heart stem cells and middlemen progenitor cells. HealthCanal ran the university’s press release based on work published this week in PLOS Pathogens.

Review talks about reality of stem cells in sports.
Over the past year, there has been a parade of headlines about athletes getting their sports injuries treated with stem cells. The EuroStemCell collaborative has published online a great review of the reasons why stem cells might work for some of those conditions, and might not. The piece dutifully starts by noting that none of these treatments have been approved for general use because none have had sufficient testing. Taking muscle, cartilage, tendon and bone repair individually the authors discuss what research has been done and what it shows. In general, the results have not been great, in large part because we haven’t yet figured out what is the best type of cell for each injury and the best way to deliver it.

False claims in stem cell for plastic surgery. CIRM-grantee Michael Longaker at Stanford has called out his fellow plastic surgeons to lead the charge in evaluating the uses of stem cells in cosmetic procedures. In an article in the journal Plastic and Reconstructive Surgery he describes research he did into 50 clinics that showed up in a google search offering stem cell face lifts. While they were claiming to inject age-reversing stem cells, he suggests they were doing no more than the established practice of injecting fat to smooth out wrinkles. While fat does have a few stem cells in it, he could find no evidence that the clinics had the necessary equipment to isolate those cells, and even if they did, there is scant research into whether those stem cells could have any impact. Popular Science and ScienceNewsline both ran stories about the journal article this week.

Don Gibbons

A Second Chance for a Spinal Cord Injury Trial, and a Powerful Reminder from Patient Advocates

Yesterday’s meeting of our governing Board was important for a number of reasons. First, the Board voted to invest some $32 million to try and get two promising projects into clinical trials – more on that in a minute – and also to try and attract some world-class researchers to California through our Research Leadership awards. It was also the first Board meeting for our new President, C. Randal Mills, Ph.D.

However, for me one of the most important parts of it was that it offered patient advocates a chance to come and talk to the Board directly, to share with them their hopes for stem cell research, and their needs in battling disabling conditions.

Yesterday a mother, Silvia Michelazzi, who suffered preeclampsia during her pregnancy and almost lost her child talked about the need for research to find better ways of preventing this deadly condition. Silvia’s daughter was born at 29 weeks and spent the first couple of months of life in a hospital neonatal intensive care unit.

One of the researchers we are funding, Dr. Mana Parast of UC San Diego, is doing some fascinating work in using iPS cells to better understand how preeclampsia works, and hopefully to find better ways of preventing it or treating it when it’s detected. We’ll be posting video of both talks in the next few weeks.

Earlier a group of individuals who have Parkinson’s disease talked to the Board about what it is like to live with that disease, to slowly lose control over their bodies and know that it was only going to get worse. They made a strong plea for more funding for stem cell research into this area.

To hear people like this speak is a powerful reminder of why we do this work; it puts a human face on the need for more research into so many areas, and why we need to do all that we can to accelerate that research, to find new treatments and cures.

Too often patients are left out of the discussion when it comes to funding research. At the stem cell agency we invite them into the room and welcome hearing from them. It’s not always easy to listen to what they have to say, particularly as we know some research is at an early stage of development and we won’t always be able to do what they want us to. But those voices are an important part of what this agency is all about. We were created by the people of California, so it’s important that the people feel they can come and talk to us any time they want.

From a business perspective yesterday’s meeting was very productive. The Board voted to invest $14.3 million in Asterias Biotherapeutics to move a stem cell therapy for spinal cord injury into clinical trials. This is the second time this approach will have been tried. The first was with Geron in 2010 and that trial, even though it ended earlier than expected because of financial reasons, showed the approach appears to be safe. Asterias is going to take it to the next level.

The other big award was $5.6 million to John Zaia at the City of Hope near Los Angeles to move his work in finding a treatment for HIV/AIDS into clinical trials.

Both are part of our Strategic Partnership program that requires them to provide matching funds for this work.

You can read all about those awards and the Research Leadership ones too in a news release we issued after the meeting.

kevin mccormack

Stem Cell Stories that Caught our Eye: Safety of First Embryonic Cell Trial, Engineered Organs, New Hips

Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.

Update on status of bioengineered organs. Kevin Mayer, writing for Genetic Engineering & Biotechnology News, this week produced the best lay overview I have read on bioengineered organs. Under the heading “bioficial organs” he covers the many ways to create scaffolds that can hold stem cells to create organs. He recounts the successes to date crafting simple organs like the trachea, bladder, vagina or nostril. He talks about the possibilities and limitations of using 3D printing to scale up production of those organs, and delves into recent reports of creating organ-like tissue on chips to be used for disease modeling and drug screening. CIRM covered many of these same topics in our workshop on Opportunities and Challenges for Tissue Repair and Regeneration.

First embryonic stem cell trial called safe. Data from the first-in-human clinical trial of cells derived from embryonic stem cells suggest the stem cell infusions were safe. The data provide welcome news to the field as a whole and hope for the million-plus Americans living with spinal cord injury, the focus of the trial. The biotech company Asterias reported the data at the American Society for Gene and Cell Therapy Thursday. The firm had bought the stem cell assets of Geron, the company that had begun the trial in 2010. In the five patients, all followed for two to three years, the team found no evidence of any ill effects from the stem cell infusion. Also, even though the researchers stopped all immune suppressants 60 days after transplant, they saw no sign of an immune response to the donor cells. TMCnews carried the company’s press release.

CIRM had provided funding for the initial Geron trial, but the company returned the award when they decided to discontinue the trial due to financial considerations. We continue to fund work in the field, which you can read about on our spinal cord injury fact sheet.

Creating mature nerve cells better mimics disease. Many teams have reported creating disease-specific nerves in the lab by creating iPS type stem cells from the skin of patients with neural diseases like Alzheimer’s, but they are less than perfect models of the disease. While they mimic the disease better than any animal model, the nerves resemble those of a newborn, not an older person likely to get the disease. Now a team at the University of Cambridge in the U.K. has developed a process that tricks the maturing iPS stem cells into continuing down the maturation pathway. The result is nerves in a dish that behave more like those in the patient. The website PhysOrg ran a story about the work that is to be published in the May 27th journal Development.

3D printing combined with stem cells for new hip. Deterioration around the site of the hip joint often results in less than optimal results when an artificial hip replaces the bad joint. Another problem is that off-the-shelf sized joints, just like shoes, don’t always fit perfectly. So, a team at the University of Southampton in the UK has developed a one-two-punch to create a better hip. First they used a 3D printer to create a hip and socket that exactly match the patient’s and then they created a bone graft with stem cells to create stronger and better fitting bone behind the socket. The web portal HealthCanal ran the university’s press release.

Ground beef made in the lab. There was a lot of silliness on the web this week about using stem cells to grow hamburgers in the lab. But Popular Science did a good old-fashioned explainer about the actual science behind the concept.

Don Gibbons

Scientists Successfully Test Stem Cell Therapy in Monkeys; Generate New Bone

Last week, researchers came that much closer to one day regrowing human bone lost to disease or injury.

In the latest issue of the journal Cell Reports, scientists from the National Institutes of Health announced that they have transformed skin cells from rhesus macaque monkeys into new bone—marking the first time such a procedure has been done in a primate. These findings are an important step towards regenerating bone in humans.

Scientists at the NIH are one step closer to using stem cell technology to regrow bone.

Scientists at the NIH are one step closer to using stem cell technology to regrow bone.

The research team, led by the National Heart, Lung and Blood Institute’s Dr. Cynthia Dunbar, used induced pluripotent stem cell (iPS cell) technology to transform the extracted cells from skin into bone. One of the main concerns of iPS cell technology, which transforms adult skin cells into embryonic-like stem cells, is the risk that those stem cells will spur tumor growth. But unlike studies in other animal models, such as mice, the team did not observe any tumor growth in the monkeys.

In this study, the research team first used standard iPS cell technology to transform adult rhesus macaque skin cells into iPS cells, which closely resembled embryonic stem cells. They then coaxed these cells into becoming early-stage bone cells, called ‘bone progenitor cells.’

At this point, the team engrafted these progenitor cells onto a type of implanted ceramic scaffold normally used by reconstructive surgeons. After a short period of time, the team noticed new bone growth.

But what was even more interesting was what they didn’t see growing on the scaffold: tumors. In fact, the only time they did observe tumor growth was in a separate set of experiments involving incredibly high doses of iPS cells. As Dunbar elaborated in last week’s news release:

“We have 
used this model to demonstrate that tumor formation of a type called a ‘teratoma’ from…iPSCs does occur; however, tumor formation is very slow and requires large numbers of iPSCs given under very hospitable conditions. We have also shown that new bone can be produced from… iPSCs, as a model for their possible clinical application.”

And even though some tumor growth occurred, stem cells such as these iPS cells would never be directly injected into humans – they would always be matured into a specific cell type first like the main set of bone progenitor cell experiments in this study.

The results presented in this study present the strong possibility that therapies based on this approach—engrafting these iPS cell-derived bone progenitor cells—could offer a solution to patients suffering from congenital bone defects or even traumatic injuries resulting in significant bone loss. While there are many potential hurdles to overcome before testing this approach in humans, the results from this primate model are far superior to similar experiments in a dish, or even in other models, such as mice. As Dunbar explained, this so-called large animal preclinical model is essential to move potential treatments from the lab bench into the clinic:

“The testing of human-derived cells in vitro or in profoundly immunodeficient mice simply cannot model these crucial preclinical safety and efficiency issues.”

Want to learn more about how stem cells can be used to rebuild bone? Check out CIRM’s recent video series: Spotlight on Bone Repair.

On stem cells, sports injuries and aging

A headline today grabbed my attention: Can your own stem cells heal your running injuries?

The answer, in a word: Duh.

That’s the whole point of tissue-specific stem cells like the ones lurking in muscles. These are the body’s reservoir for repairing and rebuilding tissues. In fact, several CIRM grantees are studying what makes muscle stem cells tick, and what make them tick less effectively as we age. A bit of shameless self-promotion, but here’s a story by yours truly from the Stanford School of Medicine magazine about work by Tom Rando, who was studying signals that direct muscle stem cells to heal injuries. His post-doctoral student Irina Conboy went on to found her own lab at the University of California, Berkeley, where she got a New Faculty Award to continue the work (we’ve blogged about her work here).

I suppose what’s implied in the headline isn’t whether stem cells normally heal injuries, which they do, but whether they can be used medically to heal injuries more effectively as in the case of the baseball pitcher Bartolo Colon.

To date, CIRM isn’t funding work relating directly to, say, shin splints or plantar fasciatis. But a number of grantees are studying not only muscle stem cells but also another type of stem cell called a mesenchymal stem cell that seems to be able to repair bone and cartilage. (Here’s a list of all CIRM awards targeting bone, muscle or cartilage.) What’s exciting about a lot of the basic stem science going on today is that it could lead to new ways of treating a wide range of different injuries, either by injecting a person’s own stem cells or by helping the native stem cells heal more effectively.

As a runner who is inevitably aging, I think it’s good news that research into chronic, debilitating conditions such as osteoarthritis could also provide some benefit down the road to my own damaged joints.

A.A.