Stem cell stories that caught our eye: healing diabetic ulcers, new spinal cord injury insights & an expanding CRISPR toolbox

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.

Stem cells heal diabetic foot ulcers in pilot study
Foot ulcers are one of the many long-term complications that diabetics face. About 15 percent of patients develop these open sores which typically appear at the bottom of the foot. In a quarter of these cases, the ulcers lead to serious infection requiring amputation.


Diabetic foot ulcers are open sores that don’t heal and in many cases leads to amputation. Image source: Izunpharma

But help may be on the horizon in the form of stem cells. Researchers at Mansoura University in Egypt recently presented results of a small study in which 10 patients with diabetic foot ulcers received standard care and another 10 patients received standard care plus injections of mesenchymal stem cells that had been collected from each patient’s own bone marrow. After just six weeks, the stem cell treated group showed a 50% reduction in the foot ulcers while the group with only standard care had a mere 7% reduction.

These superior results with the stem cells were observed even though the group receiving the stem cells had larger foot ulcers to begin with compared to the untreated patients. There are many examples of mesenchymal stem cells’ healing power which make them an extremely popular cell source for hundreds of on-going clinical trials. Mesenchymal stem cells are known to reduce inflammation and increase blood vessel formation, two properties that may be at work to give diabetic foot ulcers the chance to get better.

Medscape Medical News reported on these results which were presented at the 2016 annual meeting of the European Association for the Study of Diabetes (EASD) 2016 Annual Meeting

Suppressing nerve signals to help spinal cord injury victims
Losing the use of one’s limbs is a profound life-altering change for spinal cord injury victims. But their quality of life also suffers tremendously from the loss of bladder control and chronic pain sensations. So much so, victims often say that just improving these secondary symptoms would make a huge improvement in their lives.

While current stem cell-based clinical trials, like the CIRM-funded Asterias study, aim to reverse paralysis by restoring loss nerve signals, recent CIRM-funded animal data published in Cell Stem Cell from UC San Francisco suggest that nerve cells that naturally suppress nerve signals may be helpful for these other symptoms of spinal cord injury.


Mature inhibitory neuron derived from human embryonic stem cells is shown after successfully migrated and integrated into the injured mouse spinal cord.
Photo by Jiadong Chen, UCSF

It turns out that the bladder control loss and chronic pain may be due to overactive nerve signals. So the lab of Arnold Kriegstein transplanted inhibitory nerve cells – derived from human embryonic stem cells – into mice with spinal cord injuries. The scientists observed that these human inhibitory nerve cells, or interneurons, successfully made working connections in the damaged mouse spinal cords. The rewiring introduced by these interneurons also led to reduced pain behaviors in the mice as well as improvements in bladder control.



In a Yahoo Finance interview, Kreigstein told reporters he’s eager to push forward with these intriguing results:


Arnold Kriegstein, UCSF

“As a clinician, I’m very aware of the urgency that’s felt among patients who are often very desperate for treatment. As a result, we’re very interested in accelerating this work toward clinical trials as soon as possible, but there are many steps along the way. We have to demonstrate that this is safe, as well as replicating it in other animals. This involves scaling up the production of these human interneurons in a way that would be compatible with a clinical product.”


Expanding the CRISPR toolbox
If science had a fashion week, the relatively new gene editing technology called CRISPR/Cas9 would be sure to dominate the runway. You can think of CRISPR/Cas9 as a protein and RNA complex that acts as a molecular scissor which directly targets and cuts specific sequences of DNA in the human genome. Scientists are using CRISPR/Cas9 to develop innovative biomedical techniques such as removing disease-causing mutations in stem cells in hopes of developing potential treatments for patients suffering from diseases that have no cures.

What’s particularly interesting about the CRISPR/Cas9 system is that the Cas9 protein responsible for cutting DNA is part of a family of CRISPR associated proteins (Cas) that have similar but slightly different functions. Scientists are currently expanding the CRISPR toolbox by exploring the functions of other CRISPR associated proteins for gene editing applications.

A CIRM-funded team at UC Berkeley is particularly interested in a CRISPR protein called C2c2, which is different from Cas9 in that it targets and cuts RNA rather than DNA. Led by Berkeley professor Jennifer Doudna, the team discovered that the CRISPR/C2c2 complex has not just one, but two, distinct ways that it cuts RNA. Their findings were published this week in the journal Nature.

The first way involves creation: C2c2 helps make the guide RNAs that are used to find the RNA molecules that it wants to cut. The second way involves destruction: after the CRISPR/C2c2 complex finds it’s RNAs of choice, C2c2 can then cut and destroy the RNAs.

Doudna commented on the potential applications for this newly added CRISPR tool in a Berkeley News release:


Jennifer Doudna: Photo courtesy of

“This study expands our molecular understanding of C2c2 to guide RNA processing and provides the first application of this novel RNase. C2c2 is essentially a self-arming sentinel that attacks all RNAs upon detecting its target. This activity can be harnessed as an auto-amplifying detector that may be useful as a low-cost diagnostic.”


Gene required for sperm stem cells linked to male infertility, UCSD study suggests

Even in this day and age, when a couple is having trouble conceiving a child, it’s often the woman who is initially suspected of having infertility problems and is likely the first to seek out the advice of doctor. But according to Miles Wilkinson, professor of reproductive medicine at UC San Diego School of Medicine, infertility issues can just as likely be due to problems with sperm production in the male. In fact, about 4 million men of reproductive age in the U.S. are confronted with infertility challenges and in 30% percent of those cases, the cause of the infertility is not well understood.

Through some scientific detective work, Wilkinson and his research team have zeroed in on a gene called RhoX10 that plays an essential role in the development of adult stem cells which give rise to sperm production. The study results, funded in part by CIRM and published yesterday in Cell Reports, may help provide a path toward new treatment options for male infertility.


The process of sperm formation (spermatogenesis). Image: Wikipedia

To get at a cellular and molecular understanding of infertility, the team focused on the function of spermatogonial stem cells (SSCs). Through a multistep process within the male reproductive system, SSCs form into mature sperm cells capable of fertilizing an egg.  The SSC itself forms from primordial germ cells. The key genetic switches that help these germ cells give rise to SSCs was not well understood.  Earlier studies had shown that a group of adjacent genes, called the Rhox cluster, on the X-chromosome are expressed in the testes, suggesting a role in sperm production.

Using genetic engineering techniques, Wilkinson’s team bred mice lacking the 33 genes of the Rhox cluster. The resulting male mice showed a reduction in the number SSCs leading to low sperm number. Through a process of elimination, the team found that deleting just one of those genes, Rhox10, produced nearly the same flaw.

Rhox10 bus_HW, 9-26-16.jpg.jpg

Rhox 10: a genetic “bus” that “drives” sperm stem cells toward sperm production. Illustration by Hye-Won Song.

Further analysis, indicated Rhox10 was key to driving the development of germ cells into SSCs. So when the gene is deleted, not enough SSCs develop in the testis, leading to low sperm counts.  The researchers also found the Rhox10 is a master regulator of genes that control the germ cells’ movement from one part of the testis to another that, due to a different chemical environment, helps the germ cells transform into SSCs.

In addition to this mouse data, the team also co-authored a recent Human Molecular Genetics report with scientists at the University of Münster in Germany that connects Rhox genes and human male infertility. In the study, three RHOX genes were sequenced in 250 men with extremely low sperm counts and revealed six genetic mutations. Together, these results present solid evidence that mutations in Rhox are the culprit in at least some forms of male infertility. First author Hye-Won Song discussed this point in a university press release:

“Spermatogonial stem cells allow men — even in their 70s — to generate sperm and father children. Our finding that Rhox10 is critical for spermatogonial stem cells, coupled with the finding that human RHOX genes are mutated in infertile men, suggests that mutations in these genes cause human male infertility.”

Stem Cell Experts Discuss the Ethical Implications of Translating iPSCs to the Clinic

Part of The Stem Cellar blog series on 10 years of iPSCs.

This year, scientists are celebrating the 10-year anniversary of Shinya Yamanaka’s Nobel Prize winning discovery of induced pluripotent stem cells (iPSCs). These are cells that are very similar biologically to embryonic stem cells and can develop into any cell in the body. iPSCs are very useful in scientific research for disease modeling, drug screening, and for potential cell therapy applications.

However, with any therapy that involves testing in human patients, there are ethical questions that scientists, companies, and policy makers must consider. Yesterday, a panel of stem cell and bioethics experts at the Cell Symposium 10 Years of iPSCs conference in Berkeley discussed the ethical issues surrounding the translation of iPSC research from the lab bench to clinical trials in patients.

The panel included Shinya Yamanaka (Gladstone Institutes), George Daley (Harvard University), Christine Mummery (Leiden University Medical Centre), Lorenz Studer (Memorial Sloan Kettering Cancer Center), Deepak Srivastava (Gladstone Institutes), and Bioethicist Hank Greely (Stanford University).

iPSC Ethics Panel

iPSC Ethics Panel at the 10 Years of iPSCs Conference

Below is a summary of what these experts had to say about questions ranging from the ethics of patient and donor consent, genetic modification of iPSCs, designer organs, and whether patients should pay to participate in clinical trials.

How should we address patient or donor consent regarding iPSC banking?

Multiple institutes including CIRM are developing iPSC banks that store thousands of patient-derived iPSC lines, which scientists can use to study disease and develop new therapies. These important cell lines wouldn’t exist without patients who consent to donate their cells or tissue. The first question posed to the panel was how to regulate the consent process.

Christine Mummery began by emphasizing that it’s essential that companies are able to license patient-derived iPSC lines so they don’t have to go back to the patient and inconvenience them by asking for additional samples to make new cell lines.

George Daley and Hank Greely discussed different options for improving the informed consent process. Daley mentioned that the International Society for Stem Cell Research (ISSCR) recently updated their informed consent guidelines and now provide adaptable informed consent templates that can be used for obtaining many type of materials for human stem cell research.  Daley also mentioned the move towards standardizing the informed consent process through a single video shared by multiple institutions.

Greely agreed that video could be a powerful way to connect with patients by using talented “explainers” to educate patients. But both Daley and Greely cautioned that it’s essential to make sure that patients understand what they are getting involved in when they donate their tissue.

Greely rounded up the conversation by reminding the audience that patients are giving the research field invaluable information so we should consider giving back in return. While we can’t and shouldn’t promise a cure, we can give back in other ways like recognizing the contributions of specific patients or disease communities.

Greely mentioned the resolution with Henrietta Lack’s family as a good example. For more than 60 years, scientists have used a cancer cell line called HeLa cells that were derived from the cervical cancer cells of a woman named Henrietta Lacks. Henrietta never gave consent for her cells to be used and her family had no clue that pieces of Henrietta were being studied around the world until years later.

In 2013, the NIH finally rectified this issue by requiring that researchers ask for permission to access Henrietta’s genomic data and to include the Lacks family in their publication acknowledgements.

Hank Greely, Stanford University

Hank Greely, Stanford University

“The Lacks family are quite proud and pleased that their mother, grandmother and great grandmother is being remembered, that they are consulted on various things,” said Hank Greely. “They aren’t making any direct money out of it but they are taking a great deal of pride in the recognition that their family is getting. I think that returning something to patients is a nice thing, and a human thing.”

What are the ethical issues surrounding genome editing of iPSCs?

The conversation quickly focused on the ongoing CRISPR patent battle between the Broad Institute, MIT and UC Berkeley. For those unfamiliar with the technique, CRISPR is a gene editing technology that allows you to cut and paste DNA at precise locations in the genome. CRISPR has many uses in research, but in the context of iPSCs, scientists are using CRISPR to remove disease-causing mutations in patient iPSCs.

George Daley expressed his worry about a potential fallout if the CRISPR battle goes a certain way. He commented, “It’s deeply concerning when such a fundamentally enabling platform technology could be restricted for future gene editing applications.”

The CRISPR patent battle began in 2012 and millions of dollars in legal fees have been spent since then. Hank Greely said that he can’t understand why the Institutes haven’t settled this case already as the costs will only continue to rise, but that it might not matter how the case turns out in the end:

“My guess is that this isn’t ultimately going to be important because people will quickly figure out ways to invent around the CRISPR/Cas9 technology. People have already done it around the Cas9 part and there will probably be ways to do the same thing for the CRISPR part.”

 Christine Mummery finished off with a final point about the potential risk of trying to correct disease causing mutations in patient iPSCs using CRISPR technology. She noted that it’s possible the correction may not lead to an improvement because of other disease-causing genetic mutations in the cells that the patient and their family are unaware of.

 Should patients or donors be paid for their cells and tissue?

Lorenz Studer said he would support patients being paid for donating samples as long as the payment is reasonable, the consent form is clear, and patients aren’t trying to make money off of the process.

Hank Greely said the big issue is with inducement and whether you are paying enough money to convince people to do something they shouldn’t or wouldn’t want to do. He said this issue comes up mainly around reproductive egg donation but not with obtaining simpler tissue samples like skin biopsies. Egg donors are given money because it’s an invasive procedure, but also because a political decision was made to compensate egg donors. Greely predicts the same thing is unlikely to happen with other cell and tissue types.

Christine Mummery’s opinion was that if a patient’s iPSCs are used by a drug company to produce new successful drugs, the patient should receive some form of compensation. But she said it’s hard to know how much to pay patients, and this question was left unanswered by the panel.

Should patients pay to participate in clinical trials?

George Daley said it’s hard to justify charging patients to participate in a Phase 1 clinical trial where the focus is on testing the safety of a therapy without any guarantee that there will be beneficial outcome to the patient. In this case, charging a patient money could raise their expectations and mislead them into thinking they will benefit from the treatment. It would also be unfair because only patients who can afford to pay would have access to trials. Ultimately, he concluded that making patients pay for an early stage trial would corrupt the informed consent process. However, he did say that there are certain, rare contexts that would be highly regulated where patients could pay to participate in trials in an ethical way.

Lorenz Studer said the issue is very challenging. He knows of patients who want to pay to be in trials for treatments they hope will work, but he also doesn’t think that patients should have to pay to be in early stage trials where their participation helps the progress of the therapy. He said the focus should be on enrolling the right patient groups in clinical trials and making sure patients are properly educated about the trial they are participating.

Thoughts on the ethics behind making designer organs from iPSCs?

Deepak Srivastava said that he thinks about this question all the time in reference to the heart:

Deepak Srivastava, Gladstone Institutes

Deepak Srivastava, Gladstone Institutes

“The heart is basically a pump. When we traditionally thought about whether we could make a human heart, we asked if we could make the same thing with the same shape and design. But in fact, that’s not necessarily the best design – it’s what evolution gave us. What we really need is a pump that’s electrically active. I think going forward, we should remove the constraint of the current design and just think about what would be the best functional structure to do it. But it is definitely messing with nature and what evolution has given us.”

Deepak also said that because every organ is different, different strategies should be used. In the case of the heart, it might be beneficial to convert existing heart tissue into beating heart cells using drugs rather than transplant iPSC-derived heart cells or tissue. For other organs like the pancreas, it is beneficial to transplant stem cell-derived cells. For diabetes, scientists have shown that injecting insulin secreting cells in multiple areas of the body is beneficial to Diabetes patients.

Hank Greely concluded that the big ethical issue of creating stem cell-derived organs is safety. “Biology isn’t the same as design,” Greely said. “It’s really, really complicated. When you put something into a biological organism, the chances that something odd will happen are extremely high. We have to be very careful to avoid making matters worse.”

For more on the 10 years of iPSCs conference, check out the #CSStemCell16 hashtag on twitter.

Full Steam Ahead: First Patient is Dosed in Expanded CIRM Spinal Cord Injury Trial

Today we bring you more good news about a CIRM-funded clinical trial for spinal cord injury that’s received a lot of attention lately in the news. Asterias Biotherapeutics has treated its first patient in an expanded patient population of spinal cord injury patients who suffer from cervical, or neck, injuries.

In late August, Asterias reported that they had passed the first hurdle in their Phase 1/2a trial and showed that their stem cell therapy is safe to use in patients with a more serious form of cervical spinal cord injuries.

Earlier this month, we received more exciting updates from Asterias – this time reporting that the their embryonic stem cell-based therapy, called AST-OPC1, appeared to benefit treated patients. Five patients with severe spinal cord injuries to their neck were dosed, or transplanted, with 10 million cells. These patients are classified as AIS-A on the ASIA impairment scale – meaning they have complete injuries in which the spinal cord tissue is severed and patients lose all feeling and use of their limbs below the injury site. Amazingly, after three months, all five of the AIS-A patients have seen improvements in their movement.

Today, Asterias announced that it has treated its first patient with an AIS-B grade cervical spinal cord injury with a dose of 10 million cells at the Sheperd Center in Atlanta. AIS-B patients have incomplete neck injuries, meaning that they still have some spinal cord tissue at the injury site, some feeling in their arms and legs, but no movement. This type of spinal cord injury is still severe, but these patients have a better chance at gaining back some of their function and movement after treatment.

In a press release by Asterias, Chief Medical Officer Dr. Edward Wirth said:

“We have been very encouraged by the first look at the early efficacy data, as well as the safety profile, for AST-OPC1 in AIS-A patients, and now look forward to also evaluating efficacy and safety in AIS-B patients. AIS-B patients also have severe spinal cord injuries, but compared to AIS-A patients they have more spared tissue in their spinal cords.  This may allow these patients to have a greater chance of meaningful functional improvement after being treated with AST-OPC1 cells.”

Dr. Donald Peck Leslie, who directs the Sheperd Center and is the lead investigator at the Atlanta clinical trial site, expressed his excitement about the trials’ progress.

“As someone who regularly treats patients who have sustained paralyzing spinal cord injuries, I am encouraged by the progress we’ve seen in evaluations of AST-OPC1 in people with AIS-A injuries, particularly the improvements in hand, finger and arm function. Now, I am looking forward to continuing the evaluation of this promising new treatment in AIS-B patients, as well.”

Asterias has plans to enroll a total of five to eight AIS-B patients who will receive a dose of 10 million cells. They will continue to monitor all patients in this trial (both AIS-A and B) and will conduct long-term follow up studies to make sure that the AST-OPC1 treatment remains safe.

We hope that the brave patients who have participated in the Asterias trial continue to show improvements following treatment. Inspiring stories like that of Kris Boesen, who was the first AIS-A patient to get 10 million cells in the Asterias trial and now has regained the use of his arms and hands (and regaining some sensation in his legs), are the reason why CIRM exists and why we are working so hard to fund promising clinical trials. If we can develop even one stem cell therapy that gives patients back their life, then our efforts here at CIRM will be worthwhile.

Kris Boesen, CIRM spinal cord injury clinical trial patient.

Kris Boesen, CIRM spinal cord injury clinical trial patient.

Related Links:

Funding stem cell research targeting a rare and life-threatening disease in children


Photo courtesy Cystinosis Research Network

If you have never heard of cystinosis you should consider yourself fortunate. It’s a rare condition caused by an inherited genetic mutation. It hits early and it hits hard. Children with cystinosis are usually diagnosed before age 2 and are in end-stage kidney failure by the time they are 9. If that’s not bad enough they also experience damage to their eyes, liver, muscles, pancreas and brain.

The genetic mutation behind the condition results in an amino acid, cystine, accumulating at toxic levels in the body. There’s no cure. There is one approved treatment but it only delays progression of the disease, has some serious side effects of its own, and doesn’t prevent the need for a  kidney transplant.

Researchers at UC San Diego, led by Stephanie Cherqui, think they might have a better approach, one that could offer a single, life-long treatment for the problem. Yesterday the CIRM Board agreed and approved more than $5.2 million for Cherqui and her team to do the pre-clinical testing and work needed to get this potential treatment ready for a clinical trial.

Their goal is to take blood stem cells from people with cystinosis, genetically-modify them and return them to the patient, effectively delivering a healthy, functional gene to the body. The hope is that these genetically-modified blood stem cells will integrate with various body organs and not only replace diseased cells but also rescue them from the disease, making them healthy once again.

In a news release Randy Mills, CIRM’s President and CEO, said orphan diseases like cystinosis may not affect large numbers of people but are no less deserving of research in finding an effective therapy:

“Current treatments are expensive and limited. We want to push beyond and help find a life-long treatment, one that could prevent kidney failure and the need for kidney transplant. In this case, both the need and the science were compelling.”

The beauty of work like this is that, if successful, a one-time treatment could last a lifetime, eliminating or reducing kidney disease and the need for kidney transplantation. But it doesn’t stop there. The lessons learned through research like this might also apply to other inherited multi-organ degenerative disorders.

Asterias’ stem cell clinical trial shows encouraging results for spinal cord injury patients

jake and family

Jake Javier; Asterias spinal cord injury clinical trial participant

When researchers are carrying out a clinical trial they have two goals: first, show that it is safe (the old “do no harm” maxim) and second, show it works. One without the other doesn’t do anyone any good in the long run.

A few weeks ago Asterias Biotherapeutics showed that their CIRM-funded stem cell therapy for spinal cord injuries appeared to be safe. Now their data suggests it’s working. And that is a pretty exciting combination.

Asterias announced the news at the annual scientific meeting of the International Spinal Cord Society in Vienna, Austria. These results cover five people who got a transplant of 10 million cells. While the language is muted, the implications are very encouraging:

“While early in the study, with only 4 of the 5 patients in the cohort having reached 90 days after dosing, all patients have shown at least one motor level of improvement so far and the efficacy target of 2 of 5 patients in the cohort achieving two motor levels of improvement on at least one side of their body has already been achieved.”

What does that mean for the people treated? A lot. Remember these are people who qualified for this clinical trial because of an injury that left them pretty much paralyzed from the chest down. Seeing an improvement of two motor levels means they are regaining some use of their arms, hands and fingers, and that means they are regaining the ability to do things like feeding, dressing and bathing themselves. In effect, it is not only improving their quality of life but it is also giving them a chance to lead an independent life.


Kris Boesen, Asterias clinical trial participant

One of those patients is Kris Boesen who regained the use of his arms and hands after becoming the first patient in this trial to get a transplant of 10 million cells. We blogged about Kris here

Asterias says of the 5 patients who got 10 million cells, 4 are now 90 days out from their transplant. Of those:

  • All four have improved one motor level on at least one side
  • 2 patients have improved two motor levels on one side
  • One has improved two motor levels on both sides

What’s also encouraging is that none of the people treated experienced any serious side effects or adverse events from the transplant or the temporary use of immunosuppressive drugs.

Steve Cartt, CEO of Asterias, was understandably happy with the news and that it allows them to move to the next phase:

“We are quite encouraged by this first look at efficacy results and look forward to reporting six-month efficacy data as planned in January 2017.  We have also just recently been cleared to begin enrolling a new cohort and administering to these new patients a much higher dose of 20 million cells.  We look forward to begin evaluating efficacy results in this higher-dose cohort in the coming months as well.”

People with spinal cord injuries can regain some function spontaneously so no one is yet leaping to the conclusion that all the progress in this trial is due to the stem cells. But to see all of the patients in the 10 million stem cell group do well is at the very least a positive sign. Now the hope is that these folks will continue to do well, and that the next group of people who get a 20 million cell transplant will also see improvements.


Roman Reed, spinal cord injury patient advocate

While the team at Asterias were being cautiously optimistic, Roman Reed, whose foundation helped fund the early research that led to this clinical trial, was much less subdued in his response. He was positively giddy:

“If one patient only improves out of the five, it can be an outlier, but with everyone improving out of the five this is legit, this is real. Cures are happening!”


CIRM’s Randy Mills: New FDA rules for stem cells won’t fix the problem

For the last two days the Food and Drug Administration (FDA) has been holding a hearing in Bethesda, Maryland on new regulations that would tighten control over stem cell treatments. The FDA invited public testimony during the hearing on the regulations that would impact many of the clinics that currently offer unproven therapies

The testimony has been impassioned to say the least. Supporters of the clinics say they offer a valuable service and that patients should be allowed to decide for themselves how they want their own cells to be used. Opponents say the clinics are little more than snake oil sales people, offering bogus, unproven treatments.

One of those presenting was Randy Mills, CIRM’s President and CEO. Randy has been very vocal in the past about the need for the FDA to change the way it regulates stem cell therapies.

In California Healthline Randy explained why he thinks the rules the FDA is proposing will not fix the problem, and may even make it worse:

FDA Must Find A Middle Ground For Sake Of Patients


Randy Mills

We aren’t happy, as a lot of people aren’t happy, with the proliferation of these stem cell clinics — some of which are probably doing good work. But some are clearly making rather outlandish claims for which there’s no real data. 

There are a couple of conditions coming together to create this storm.

One is that the need is very real. These patients are really struggling. They don’t have alternatives. They’re desperate and they need help. It’s not in the realm of possibility to talk to somebody who is suffering as badly as these patients are and to say, ‘You have to wait a few more decades for the science to catch up.’

On the other hand, we have a regulatory paradigm that only provides two pathways to put a cell therapy onto the market. One pathway is the most intense regulatory requirement anywhere in the world for any product — the biologics license application through the FDA, which takes 10 to 20 years and costs over $1 billion.

The other is through the exemptions the FDA has made, which require absolutely no pre-market approval whatsoever. You can be on the market in days, with no data.

The regulatory burden associated with one is massive and the other is almost nonexistent.

So it’s not at all surprising that we’re seeing a proliferation of these stem cell clinics popping up that are operating under the assumption that they fall under the exemption.

What the FDA is doing now is saying, ‘We’re not happy with this. We’re going to define some terms more narrowly than in the past … and make it more difficult to legally be on the market under the less burdensome regulatory pathway.’

That’s what this meeting is about.

The problem with their strategy is twofold. It doesn’t address the patients, or the need side of the equation. And I don’t think it has a chance of actually working because the FDA will acknowledge that they do not have the resources to enforce these types of regulations at the clinic level.

They would have to be essentially regulating the practice of physicians, which is well beyond their capabilities. Even if they were able to enforce it, it would just drive these patients somewhere else.

We’re advocating for the creation of some middle pathway that would bring essentially unregulated therapies into the regulatory fold, but in a manner which could be complied with.

I would rather know these clinics are being regulated and collecting data than have them operating under the radar screen of the FDA. I would like there to be a formal pre-market review of these therapies before they’re put on the market. I would like there to be safety and efficacy data.

I’m going to try hard to get the FDA to see that just plugging this hole won’t make the problem go away.

Thinking that they’re going to strengthen the regulation and that patients are going to be satisfied that there’s absolutely no chance for help is naive.

There isn’t a lot of evidence to suggest these types of procedures are overly risky. It’s not that they don’t have risk, but everything in medicine does. If you’re a patient who has absolutely no alternative, you’re probably willing to take the chance.

Salk scientists explain why brain cells are genetically diverse


I’ve always wondered why some sets of genetically identical twins become not so identical later in life. Sometimes they differ in appearance. Other times, one twin is healthy while the other is plagued with a serious disease. These differences can be explained by exposure to different environmental factors over time, but there could also be a genetic explanation involving our brains.

The brain is composed of approximately 100 billion cells called neurons, each with a DNA blueprint that contains instructions that determine the function of these neurons in the brain. Originally it was thought that all cells, including neurons, have the same DNA. But more recently, scientists discovered that the brain is genetically diverse and that neurons within the same brain can have slightly different DNA blueprints, which could give them slightly different functions.

Jumping genes and genetic diversity


Fred “Rusty” Gage: Photo courtesy Salk Institute

Why and how neurons have differences in their DNA are questions that Salk Institute professor Fred Gage has pursued for more than a decade. In 2005, his lab discovered a mechanism during neural development that causes differences in the DNA of neurons. As a brain stem cell develops into a neuron, long interspersed nuclear elements (L1s), which are small pieces of DNA, copy and paste themselves, seemingly at random, throughout a neuron’s genome.

These elements were originally dubbed “jumping genes” because of their ability to hop around and insert themselves into DNA. It turns out that L1s do more than copy and paste themselves to create changes in DNA, they also can delete chunks of DNA. In a CIRM-funded study published this week in the journal Nature Neuroscience, Gage and colleagues at the Salk Institute reported new insights into L1 activity and how it creates genetic diversity in the brain.

Copy, paste, delete

Gage and his team had clues that L1s can cause DNA deletions in neurons back in 2013. They used a technique called single-cell sequencing to record the sequence of individual neuronal genomes and saw that some of their genomes had large sections of DNA added or missing.

They thought that L1s could be the reason for these insertions and deletions, but didn’t have proof until their current study, which used an improved method to identify areas of the neuronal genome modified by L1s. This method, combined with a computer algorithm that can easily tell the difference between various types of L1 modifications, revealed that areas of the genome with L1s were susceptible to DNA cutting caused by enzymes that home in on the L1 sequences. These breaks in the DNA then cause the observed deletions.

Gage explained their findings in a news release:

“In 2013, we discovered that different neurons within the same brain have various complements of DNA, suggesting that they function slightly differently from each other even within the same person. This recent study reveals a new and surprising form of variation that will help us understand the role of L1s, not only in healthy brains but in those affected by schizophrenia and autism.”

Jennifer Erwin, first author on the study, further elaborated:

“The surprising part was that we thought all L1s could do was insert into new places. But the fact that they’re causing deletions means that they’re affecting the genome in a more significant way,” says Erwin, a staff scientist in Gage’s group.”

Insights into brain disorders

It’s now known that L1s are important for the brain’s genetic diversity, but Gage also believes that L1s could play a role in causing brain disorders like schizophrenia and autism where there is heightened L1 activity in the neurons of these patients. In future work, Gage and his team will study how L1s can cause changes in genes associated with schizophrenia and autism and how these changes can effect brain function and cause disease.

Making a deposit in the Bank: using stem cells from children with rare diseases to find new treatments

Part of The Stem Cellar series on ten years of iPS cells


For Chris Waters, the motivation behind her move from big pharmaceutical companies and biotech to starting a non-profit organization focused on rare diseases in children is simple: “What’s most important is empowering patient families and helping them accelerate research to the clinical solutions they so urgently need for their child ,” she says.

Chris is the founder of Rare Science. Their mission statement – Accelerating Cures for RARE Kids – bears a striking resemblance to ours here at CIRM, so creating a partnership between us just seemed to make sense. At least it did to Chris. And one thing you need to know about Chris, is that when she has an idea you should just get out of the way, because she is going to make it happen.

“The biggest gap in drug development is that we are not addressing the specific needs of children, especially those with rare diseases.  We need to focus on kids. They are our future. If it takes 14 years and $2 billion to get FDA approval for a new drug, how is that going to help the 35% of the 200 million children across the world that are dying before 5 years of age because they have a rare disease? That’s why we created Rare Science. How do we help kids right now, how do we help the families? How do we make change?”

Banking on CIRM for help

One of the changes she wanted to make was to add the blood and tissue samples from one of the rare disease patient communities she works with to the CIRM Induced Pluripotent Stem Cell Bank. This program is collecting samples from up to 3,000 Californians – some of them healthy, some suffering from diseases such as autism, Alzheimer’s, heart, lung and liver disease and blindness. The samples will be turned into iPS cells – pluripotent stem cells that have the ability to be turned into any other type of cell in the body – enabling researchers to study how the diseases progress, and hopefully leading to the development of new therapies.



Lilly Grossman: photo courtesy LA Times

Chris says many kids with rare diseases can struggle for years to get an accurate diagnosis and even when they do get one there is often nothing available to help them. She says one San Diego teenager, Lilly Grossman, was originally diagnosed with Cerebral Palsy and it took years to identify that the real cause of her problems was a mutation in a gene called ADCY5, leading to abnormal involuntary movement. At first Lily’s family felt they were the only ones facing this problem. They have since started a patient family organization ( that supports others with this condition.

“Even though we know that the affected individuals have the gene mutation, we have no idea how the gene causes the observable traits that are widely variable across the individuals we know.  We need research tools to help us understand the biology of ADCY5 and other rare disease – it is not enough to just know the gene mutation. We always wanted to do a stem cell line that would help us get at these biological questions.”

Getting creative

But with little money to spend Chris faced what, for an ordinary person, might have been a series of daunting obstacles. She needed consent forms so that everyone donating tissue, particularly the children, knew exactly what was involved in giving samples and how those samples would be used in research.  She also needed materials to collect the samples. In addition she needed to find doctors and sites around the world where the families were located to help with the sample collection.  All of this was going to cost money, which for any non-profit is always in short supply.

So she went to work herself, creating a Research Participant’s Bill of Rights – a list of the rights that anyone taking part in medical research has. She developed forms explaining to children, teenagers and parents what happens if they give skin or blood samples as part of medical research, telling them how an individual’s personal medical health history may be used in research studies. And then she turned to medical supply companies and got them to donate the tubes and other materials that would be needed to collect and preserve the tissue and blood samples.

Even though ADCY5 is a very rare condition, Chris has collected samples from 42 individuals representing 13 different families, some affected with the condition as well as their unaffected siblings and parents. These samples come from families all around the world, from the US and Europe, to Canada and Australia.

“With CIRM we can build stem cell lines. We can lower the barrier of access for researchers who want to utilize these valuable stem cell lines that they may not have the resources to generate themselves.  The cell lines, in the hands of researchers, can potentially accelerate understanding of the biology. They can help us identify targets to focus on for therapies. They can help us screen currently approved medications or drugs, so we have something now that could help these kids now, not 14 years from now.”

The samples Chris collects will be made available to researchers not just here in the US, but around the world. Chris hopes this program will serve as a model for other rare diseases, creating stem cell lines from them to help close the gap between discovery research and clinical impact.

Rare bears for rare disease

But in everything she does, in the end it always comes down to the patient families. Chris says so many children and families battling a rare disease feel they are alone. So she created with her team, the RARE Bear program to let them know they aren’t alone, that they are part of a worldwide community of support. She says each bear is handmade by the RARE Bear Army which spans 9 countries including 45 states in the US.  Each RARE Bear is different, because “they are all one of a kind bears for one of a kind kids. And that’s why we are here, to help rare kids one bear at a time.”  The RARE Bear program, also helps with rare disease awareness, patient outreach and rare disease community building which is key for RARE Science Research Programs.

It’s working. Chris recently got this series of photos and notes from the parents of a young girl in England, after they got their bear.

“I wanted to say a huge heartfelt thank you for my daughters Rare bear. It arrived today to Essex, England & as you can see from my pictures Isabella loves her already! We have named her Faith as a reminder to never give up!”

Stem cell stories that caught our eye: improving heart care, fixing sickle cell disease, stem cells & sugar

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.

Using “disease in a dish” model to improve heart care
Medications we take to improve our quality of life might actually be putting our lives in danger. For example, some studies have shown that high doses of pain killers like ibuprofen can increase our risk of heart problems or stroke. Now a new study has found a way of using a person’s own cells, to make sure the drugs they are given help, and don’t hinder their recovery.


Cardiac muscle cells from boy with inherited heart arrhythmia.
Image: Emory University

Researchers at Emory University in Atlanta took skin cells from a teenage boy with an inherited heart arrhythmia, and turned them into induced pluripotent stem (iPS) cells – a kind of cell that can then be turned into any other cell in the body. They then turned the iPS cells into heart muscle cells and used those cells to test different medications to see which were most effective at treating the arrhythmia, without causing any toxic or dangerous side effects.

The study was published in Disease Models & Mechanisms. In a news release co-author Peter Fischbach, said the work enables them to study the impact on a heart cell, without taking any heart cells from patients:

“We were able to recapitulate in a petri dish what we had seen in the patient. The hope is that in the future, we will be able to do that in reverse order.”

Switching a gene “off” to ease sickle cell disease pain:
Sickle cell disease (SCD) is a nasty, inherited condition that not only leaves people in debilitating pain, but also shortens their lives. Now researchers at Dana-Farber and Boston Children’s Cancer and Blood Disorders Center have found a way that could help ease that pain in some patients.

SCD is caused by a mutation in hemoglobin, which helps carry oxygen around in our blood. The mutation causes normally soft, round blood cells to become stiff and sickle-shaped. These often stick together, blocking blood flow, causing intense pain, organ damage and even strokes.

In this study, published in the Journal of Clinical Investigation, researchers took advantage of the fact that SCD is milder in people whose red blood cells have a fetal form of hemoglobin, something which for most of us tails off after we are born. They found that by “switching off” a gene called BCL11A they could restart that fetal form of hemoglobin.

They did this in mice successfully. Senior author David Williams, in a story picked up by Health Medicine Network, says they now hope to try this in people:

“BCL11A represses fetal hemoglobin, which does not lead to sickling, and also activates beta hemoglobin, which is affected by the sickle-cell mutation. So when you knock BCL11A down, you simultaneously increase fetal hemoglobin and repress sickling hemoglobin, which is why we think this is the best approach to gene therapy in sickle cell disease.”

CIRM already has a similar approach in clinical trials. UCLA’s Don Kohn is using a genetic editing technique to add a novel therapeutic hemoglobin gene that blocks sickling of the red blood cells and hopefully cure the patient altogether. This fun video gives a quick summary of the clinical trial:

How a stem cell’s sugar metabolism controls its transformation potential
While CIRM makes its push to fund 50 more stem cell-based clinical trials by 2020, we also continue to fund research that helps us better understand stem cells. Case in point, this week a UCLA research team funded in part by CIRM reported that an embryonic stem cell’s sugar metabolism changes as its develops and that this difference has big implications on cell fate.



The study, published in Cell Stem Cell, compared so-called “naïve” and “primed” human embryonic stem cells (ESCs). The naïve cells represent a very early stage of embryo development and the primed cells represent a slightly later stage. All cells use the sugar, glucose, to provide energy, though the researchers discovered that the naive stem cells “ate up” glucose four times faster than the primed stem cells (A fascinating side note is they also found the exact opposite behavior in mice: naïve mouse ESCs metabolize glucose slower than primed mouse ESCs. This is a nice example of why it’s important to study human cells to understand human biology). It turns out this difference effects each cells ability to differentiate, or specialize, into a mature cell type. When the researchers added a drug that inhibits glucose metabolism to the naïve cells and stimulated them down a brain cell fate, three times more of the cells specialized into nerve cells.

Their next steps are to understand exactly how the change in glucose metabolism affects differentiation. As Heather Christofk mentioned in a university press release, these findings could ultimately help researchers who are manipulating stem cells to develop cell therapy products:

“Our study proves that if you carefully alter the sugar metabolism of pluripotent stem cells, you can affect their fate. This could be very useful for regenerative medicine.”