Buildup of random mutations in adult stem cells doesn’t explain varying frequency of cancers

To divide or not to divide?

 It’s a question every cell in your body must constantly ask itself. Cells in your small intestine, for instance, replace themselves about every three days so the cells in that tissue must divide frequently to replenish the tissue. Liver cell are less active and turn over about once a year. And on the other extreme, the cells in the lens of the eye are kept over a life time.

The cell cycle, an exquisitely controlled process.

The cell cycle, an exquisitely controlled process. (Source wikipedia)

It’s no wonder that the process of cell division, also called the cell cycle, is exquisitely controlled by many different proteins and signaling molecules. It also makes sense that mutations in genes that produce the cell cycle proteins, could cause the regulation of cell division to go awry.

Mutations pave a path to cancer

Accumulation of enough mutations over a lifetime can lead to uncontrolled cell growth and eventually cancer. Adult stem cells are thought to be especially vulnerable to cell cycle mutations since these cells already have the capacity to self-renew and can pass mutations to their daughter cells.

Now, gene mutations can be inherited from one’s parents or caused by environmental factors like UV rays from the sun or acquired by random mistakes that occur as DNA replicates itself during cells division. Studying how the accumulation of these different mutation types impact cell division is important for understanding the formation of cancers. Results from a study in early 2015 indicated that mutations caused by random mistakes in DNA replication had a bigger impact on many cancers than mutations arising from lifestyle and environmental factors.

“Bad luck” mutations may not be the most harmful

But a new research publication in Nature suggests that, while these “bad luck” mutations can drive the development of cancer, they probably are not the main contributors. To reach this conclusion, the research team – which hails from the University Medical Center Utrecht in the Netherlands – directly measured mutation rates in human adult stem cells collected from donors as young as three years and as old as 87. In particular, stem cells from the liver, small intestine and colon were obtained. Individual stem cells were grown in the lab into mini-organs, or organoids, that resemble the structures of the source tissue. After studying these organoids, they determined that the frequency of cancer is very different in these organs, with the incidence cancer in the colon being much higher than in the other two organs.

Mutation rate the same, despite age, despite organ type

Through a various genetic analyses, the team found that an interesting pattern: the mutation rate was the same – about 40 mutations per year – for all organ types and all ages despite the higher incidence of colon cancer and older age-related cancers. Dr. Ruben van Boxtel, the team leader, expressed his reaction to these results in an interview with Medical News Today:

“We were surprised to find roughly the same mutation rate in stem cells from organs with different cancer incidence. This suggests that simply the gradual accumulation of more and more ‘bad luck’ DNA errors over time cannot explain the difference we see in cancer incidence – at least for some cancers.”

Still, the team did observe that different types of random mutations were specific to one organ over the other. These differences may help explain why the colon, for example, has a higher cancer incidence than the liver or small intestine. Van Boxtel and his team are interested in examining this result further:

“It seems ‘bad luck’ is definitely part of the story but we need much more evidence to find out how, and to what extent. This is what we want to focus on next.”

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

cystinosis

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.

Seeing is believing: how some scientists – including two funded by CIRM – are working to help the blind see

retinitis pigmentosas_1

How retinitis pigmentosa destroys vision – new stem cell research may help reverse that

“A pale hue”. For most of us that is a simple description, an observation about color. For Kristin Macdonald it’s a glimpse of the future. In some ways it’s a miracle. Kristin lost her sight to retinitis pigmentosa (RP). For many years she was virtually blind. But now, thanks to a clinical trial funded by CIRM she is starting to see again.

Kristin’s story is one of several examples of restoring sight in an article entitled “Why There’s New Hope About Ending Blindness” in the latest issue of National Geographic.  The article explores different approaches to treating people who were either born without vision or lost their vision due to disease or injury.

Two of those stories feature research that CIRM has funded. One is the work that is helping Kristin. Retinitis pigmentosa is a relatively rare condition that destroys the photoreceptors at the back of the eye, the cells that actually allow us to sense light. The National Geographic piece highlights how a research team at the University of California, Irvine, led by Dr. Henry Klassen, has been working on a way to use stem cells to replace and repair the cells damaged by RP.

“Klassen has spent 30 years studying how to coax progenitor cells—former stem cells that have begun to move toward being specific cell types—into replacing or rehabilitating failed retinal cells. Having successfully used retinal progenitor cells to improve vision in mice, rats, cats, dogs, and pigs, he’s testing a similar treatment in people with advanced retinitis pigmentosa.”

We recently blogged about this work and the fact that this team just passed it’s first major milestone – – showing that in the first nine patients treated none experienced any serious side effects. A Phase 1 clinical trial like this is designed to test for safety, so it usually involves the use of relatively small numbers of cells. The fact that some of those treated, like Kristin, are showing signs of improvement in their vision is quite encouraging. We will be following this work very closely and reporting new results as soon as they are available.

The other CIRM-supported research featured in the article is led by what the writer calls “an eyeball dream team” featuring University of Southern California’s Dr. Mark Humayun, described as “a courteous, efficient, impeccably besuited man.” And it’s true, he is.

The team is developing a stem cell device to help treat age-related macular degeneration, the leading cause of vision loss in the US.

“He and his fellow principal investigator, University of California, Santa Barbara stem cell biologist Dennis Clegg, call it simply a patch. That patch’s chassis, made of the same stuff used to coat wiring for pacemakers and neural implants, is wafer thin, bottle shaped, and the size of a fat grain of rice. Onto this speck Clegg distributes 120,000 cells derived from embryonic stem cells.”

Humayun and Clegg have just started their clinical trial with this work so it is likely going to be some time before we have any results.

These are just two of the many different approaches, using several different methods, to address vision loss. The article is a fascinating read, giving you a sense of how science is transforming people’s lives. It’s also wonderfully written by David Dobbs, including observations like this:

“Neuroscientists love the eye because “it’s the only place you see the brain without drilling a hole,” as one put it to me.”

For a vision of the future, a future that could mean restoring vision to those who have lost it, it’s a terrific read.

 

Unlocking the secrets of how stem cells decide what kind of cell they’re going to be

Laszlo Nagy, Ph.D., M.D.

Laszlo Nagy, Ph.D., M.D.: Sanford Burnham Prebys Medical Discovery Institute

Before joining CIRM I thought OCT4 was a date on the calendar. But a new study says it may be a lot closer to a date with destiny, because this study says OCT4 helps determine what kinds of cell a stem cell will become.

Now, before we go any further I should explain for people who have as strong a science background as I do – namely none – that OCT4 is a transcription factor, this is a protein that helps regulate gene activity by turning certain genes on at certain points, and off at others.

The new study, by researches at Sanford Burnham Prebys Medical Discovery Institute (SBP), found that OCT4 plays a critical role in priming genes that cause stem cells to differentiate or change into other kinds of cells.

Why is this important? Well, as we search for new ways of treating a wide variety of different diseases we need to find the most efficient and effective way of turning stem cells into the kind of cells we need to regenerate or replace damaged tissue. By understanding the mechanisms that determine how a stem cell differentiates, we can better understand what we need to do in the lab to generate the specific kinds of cells needed to replace those damaged by, say, heart disease or cancer.

The study, published in the journal Molecular Cell, shows how OCT4 works with other transcription factors, sometimes directing a cell to go in one direction, sometimes in another. For example, it collaborates with a vitamin A (aka retinoic acid) receptor (RAR) to convert a stem cell into a neuronal precursor, a kind of early stage brain cell. However, if OCT4 interacts with another transcription factor called beta-catenin then the stem cell goes in another regulatory direction altogether.

In an interview with PhysOrg News, senior author Laszlo Nagy said this finding could help develop more effective methods for producing specific cell types to be used in therapies:

“Our findings suggest a general principle for how the same differentiation signal induces distinct transitions in various types of cells. Whereas in stem cells, OCT4 recruits the RAR to neuronal genes, in bone marrow cells, another transcription factor would recruit RAR to genes for the granulocyte program. Which factors determine the effects of differentiation signals in bone marrow cells – and other cell types – remains to be determined.”

In a way it’s like programming all the different devices that are attached to your TV at home. If you hit a certain combination of buttons you get to one set of stations, hit another combination and you get to Netflix. Same basic set up, but completely different destinations.

“In a sense, we’ve found the code for stem cells that links the input—signals like vitamin A and Wnt—to the output—cell type. Now we plan to explore whether other transcription factors behave similarly to OCT4—that is, to find the code in more mature cell types.”

 

 

Out of the mouths, or in this case hearts, of babes comes a hopeful therapy for heart attack patients

Pediatric-Congenital-Heart-Disease-patient-300x200

Lessons learned from babies with heart failure could now help adults

Inspiration can sometimes come from the most unexpected of places. For English researcher Stephen Westaby it came from seeing babies who had heart attacks bounce back and recover. It led Westaby to a new line of research that could offer hope to people who have had a heart attack.

Westaby, a researcher at the John Radcliffe hospital in Oxford, England, found that implanting a novel kind of stem cell in the hearts of people undergoing surgery following a heart attack had a surprisingly significant impact on their recovery.

Westaby got his inspiration from studies showing babies who had a heart attack and experienced scarring on their heart, were able to bounce back and, by the time they reached adolescence, had no scarring. He wondered if it was because the babies’ own heart stem cells were able to repair the damage.

Scarring is a common side effect of a heart attack and affects the ability of the heart to be able to pump blood efficiently around the body. As a result of that diminished pumping ability people have less energy, and are at increased risk of further heart problems. For years it was believed this scarring was irreversible. This study, published in the Journal of Cardiovascular Translational Research, suggests it may not be.

Westaby and his team implanted what they describe as a “novel mesenchymal precursor (iMP)” type of stem cell in the hearts of patients who were undergoing heart bypass surgery following a heart attack. The cells were placed in parts of the heart that showed sizeable scarring and poor blood flow.

Two years later the patients showed a 30 percent improvement in heart function, a 40 percent reduction in scar size, and a 70 percent improvement in quality of life.

In an interview with the UK Guardian newspaper, Westaby admitted he was not expecting such a clear cut benefit:

“Quite frankly it was a big surprise to find the area of scar in the damaged heart got smaller,”

Of course it has to be noted that the trial was small, only involving 11 patients. Nonetheless the findings are important and impressive. Westaby and his team now hope to do a much larger study.

CIRM is funding a clinical trial with Capricor that is taking a similar approach, using stem cells to rejuvenate the hearts of patients who have had heart attacks.

Fred Lesikar, one of the patient’s in the first phase of that trial, experienced a similar benefit to those in the English trial and told us about it in our Stories of Hope.

Stem cell stories that caught our eye: turning on T cells; fixing our brains; progress and trends in stem cells; and one young man’s journey to recover from a devastating injury

Healthy_Human_T_Cell

A healthy T cell

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.

Directing the creation of T cells. To paraphrase the GOP Presidential nominee, any sane person LOVES, LOVES LOVES their T cells, in a HUGE way, so HUGE. They scamper around the body getting rid of viruses and the tiny cancers we all have in us all the time. A CIRM-funded team at CalTech has worked out the steps our genetic machinery must take to make more of them, a first step in letting physicians turn up the action of our immune systems.

We have known for some time the identity of the genetic switch that is the last, critical step in turning blood stem cells into T cells, but nothing in our body is as simple as a single on-off event. The Caltech team isolated four genetic factors in the path leading to that main switch and, somewhat unsuspected, they found out those four steps had to be activated sequentially, not all at the same time. They discovered the path by engineering mouse cells so that the main T cell switch, Bcl11b, glows under a microscope when it is turned on.

“We identify the contributions of four regulators of Bcl11b, which are all needed for its activation but carry out surprisingly different functions in enabling the gene to be turned on,” said Ellen Rothenberg, the senior author in a university press release picked up by Innovations Report. “It’s interesting–the gene still needs the full quorum of transcription factors, but we now find that it also needs them to work in the right order.”

Video primer on stem cells in the brain.  In conjunction with an article in its August issue, Scientific American posted a video from the Brain Forum in Switzerland of Elena Cattaneo of the University of Milan explaining the basics of adult versus pluripotent stem cells, and in particular how we are thinking about using them to repair diseases in the brain.

The 20-minute talk gives a brief review of pioneers who “stood alone in unmarked territory.” She asks how can stem cells be so powerful; and answers by saying they have lots of secrets and those secrets are what stem cell scientist like her are working to unravel.  She notes stem cells have never seen a brain, but if you show them a few factors they can become specialized nerves. After discussing collaborations in Europe to grow replacement dopamine neurons for Parkinson’s disease, she went on to describe her own effort to do the same thing in Huntington’s disease, but in this case create the striatal nerves lost in that disease.

The video closes with a discussion of how basic stem cell research can answer evolutionary questions, in particular how genetic changes allowed higher organisms to develop more complex nervous systems.

kelley and kent

CIRM Science Officers Kelly Shepard and Kent Fitzgerald

A stem cell review that hits close to home.  IEEE Pulse, a publication for scientists who mix engineering and medicine and biology, had one of their reporters interview two of our colleagues on CIRM’s science team. They asked senior science officers Kelly Shepard and Kent Fitzgerald to reflect on how the stem cell field has progressed based on their experience working to attract top researchers to apply for our grants and watching our panel of outside reviewers select the top 20 to 30 percent of each set of applicants.

One of the biggest changes has been a move from animal stem cell models to work with human stem cells, and because of CIRM’s dedicated and sustained funding through the voter initiative Proposition 71, California scientists have led the way in this change. Kelly described examples of how mouse and human systems are different and having data on human cells has been critical to moving toward therapies.

Kelly and Kent address several technology trends. They note how quickly stem cell scientists have wrapped their arms around the new trendy gene editing technology CRISPR and discuss ways it is being used in the field. They also discuss the important role of our recently developed ability to perform single cell analysis and other technologies like using vessels called exosomes that carry some of the same factors as stem cells without having to go through all the issues around transplanting whole cells.

“We’re really looking to move things from discovery to the clinic. CIRM has laid the foundation by establishing a good understanding of mechanistic biology and how stem cells work and is now taking the knowledge and applying it for the benefit of patients,” Kent said toward the end of the interview.

jake and family

Jake Javier and his family

Jake’s story: one young man’s journey to and through a stem cell transplant; As a former TV writer and producer I tend to be quite critical about the way TV news typically covers medical stories. But a recent story on KTVU, the Fox News affiliate here in the San Francisco Bay Area, showed how these stories can be done in a way that balances hope, and accuracy.

Reporter Julie Haener followed the story of Jake Javier – we have blogged about Jake before – a young man who broke his spine and was then given a stem cell transplant as part of the Asterias Biotherapeutics clinical trial that CIRM is funding.

It’s a touching story that highlights the difficulty treating these injuries, but also the hope that stem cell therapies holds out for people like Jake, and of course for his family too.

If you want to see how a TV story can be done well, this is a great example.

CIRM Board targets diabetes and kidney disease with big stem cell research awards

diabetes2

A recent study  estimated there may be more than 500 million people worldwide who have diabetes. That’s an astounding figure and makes diabetes one of the largest chronic disease epidemics in human history.

One of the most serious consequences of untreated or uncontrolled diabetes is kidney damage. That can lead to fatigue, weakness, confusion, kidney failure and even death. So two decisions taken by the CIRM Board today were good news for anyone already suffering from either diabetes or kidney disease. Or both.

The Board awarded almost $10 million to Humacyte to run a Phase 3 clinical trial of an artificial vein needed by people undergoing hemodialysis – that’s the most common form of dialysis for people with kidney damage. Hemodialysis helps clean out impurities and toxins from the blood. Without it waste will build up in the kidneys with devastating consequences.

The artificial vein is a kind of bioengineered blood vessel. It is implanted in the individual’s arm and, during dialysis, is connected to a machine to move the blood out of the body, through a filter, and then back into the body. The current synthetic version of the vein is effective but is prone to clotting and infections, and has to be removed regularly. All this puts the patient at risk.

Humacyte’s version – called a human acellular vessel or HAV – uses human cells from donated aortas that are then seeded onto a biodegradable scaffold and grown in the lab to form the artificial vein. When fully developed the structure is then “washed” to remove all the cellular tissue, leaving just a collagen tube. That is then implanted in the patient, and their own stem cells grow onto it, essentially turning it into their own tissue.

In earlier studies Humacyte’s HAV was shown to be safer and last longer than current versions. As our President and CEO, Randy Mills, said in a news release, that’s clearly good news for patients:

“This approach has the potential to dramatically improve our ability to care for people with kidney disease. Being able to reduce infections and clotting, and increase the quality of care the hemodialysis patients get could have a significant impact on not just the quality of their life but also the length of it.”

There are currently almost half a million Americans with kidney disease who are on dialysis. Having something that makes life easier, and hopefully safer, for them is a big plus.

The Humacyte trial is looking to enroll around 350 patients at three sites in California; Sacramento, Long Beach and Irvine.

While not all people with diabetes are on dialysis, they all need help maintaining healthy blood sugar levels, particularly people with type 1 diabetes. That’s where the $3.9 million awarded to ViaCyte comes in.

We’re already funding a clinical trial with ViaCyte  using an implantable delivery system containing stem cell-derived cells that is designed to measure blood flow, detect when blood sugar is low, then secrete insulin to restore it to a healthy level.

This new program uses a similar device, called a PEC-Direct. Unlike the current clinical trial version, the PEC-Direct allows the patient’s blood vessels to directly connect, or vasularize, with the cells inside it. ViaCyte believes this will allow for a more robust engraftment of the stem cell-derived cells inside it and that those cells will be better able to produce the insulin the body needs.

Because it allows direct vascularization it means that people who get the delivery system  will also need to get chronic immune suppression to stop their body’s immune system attacking it. For that reason it will be used to treat patients with type 1 diabetes that are at high risk for acute complications such as severe hypoglycemic (low blood sugar) events associated with hypoglycemia unawareness syndrome.

In a news release Paul Laikind, Ph.D., President and CEO of ViaCyte, said this approach could help patients most at risk.

“This high-risk patient population is the same population that would be eligible for cadaver islet transplants, a procedure that can be highly effective but suffers from a severe lack of donor material. We believe PEC-Direct could overcome the limitations of islet transplant by providing an unlimited supply of cells, manufactured under cGMP conditions, and a safer, more optimal route of administration.”

The Board also approved more than $13.6 million in awards under our Discovery program. You can see the winners here.

 

Stem cell transplant offers Jake a glimpse of hope

Jake

Jake Javier surrounded by friends; Photo courtesy Julie Haener KTVU

On Thursday, July 7th, Jake Javier became the latest member of a very select group. Jake underwent a stem cell transplant for a spinal cord injury at Santa Clara Valley Medical Center here in the San Francisco Bay Area.

The therapy is part of the CIRM-funded clinical trial run by Asterias Biotherapeutics. For Asterias it meant it had hit a significant milestone (more on that later). But for Jake, it was something far more important. It was the start of a whole new phase in his life.

Jake seriously injured his spinal cord in a freak accident after diving into a swimming pool just one day before he was due to graduate from San Ramon Valley high school. Thanks, in part, to the efforts of the tireless patient advocate and stem cell champion Roman Reed, Jake was able to enroll in the Asterias trial.

astopc1The goal of the trial is to test the safety of transplanting three escalating doses of AST-OPC1 cells. These are a form of cell called oligodendrocyte progenitors, which are capable of becoming several different kinds of brain cells, some of which play a supporting role and help protect nerve cells in the central nervous system – the area damaged in spinal cord injury.

To be eligible, individuals have to have experienced a severe neck injury in the last 30 days, one that has left them with no sensation or movement below the level of their injury, and that means they have typically lost all lower limb function and most hand and arm function.

The first group of three patients was completed in August of last year. This group was primarily to test for safety, to make sure this approach was not going to cause any harm to patients. That’s why the individuals enrolled were given the relatively small dose of 2 million cells. So far none of the patients have experienced any serious side effects, and some have even shown some small improvements.

In contrast, the group Jake is in were given 10 million cells each. Jake was the fifth person treated in this group. That means Asterias can now start assessing the safety data from this group and, if there are no problems, can plan on enrolling people for group 3 in about two months. That group of patients will get 20 million cells.

It’s these two groups, Jakes and group 3, that are getting enough cells that it’s hoped they will see some therapeutic benefits.

In a news release, Steve Cartt, President and CEO of Asterias, said they are encouraged by the progress of the trial so far:

“Successful completion of enrollment and dosing of our first efficacy cohort receiving 10 million cells in our ongoing Phase 1/2a clinical study represents a critically important milestone in our AST-OPC1 clinical program for patients with complete cervical spinal cord injuries. In addition, while it is still very early in the development process and the patient numbers are quite small, we are encouraged by the upper extremity motor function improvements we have observed so far in patients previously enrolled and dosed in the very low dose two million cell cohort that had been designed purely to evaluate safety.”

 

jake and familyJake and his family are well aware that this treatment is not going to be a cure, that he won’t suddenly get up and walk again. But it could help him in other, important ways, such as possibly getting back some ability to move his hands.

The latest news is that Jake is doing well, that he experienced some minor problems after the surgery but is bouncing back and is in good spirits.

Jake’s mother Isabelle said this has been an overwhelming experience for the family, but they are getting through it thanks to the love and support of everyone who hears Jake’s story. She told CIRM:

 “We are all beyond thrilled to have an opportunity of this magnitude. Just the thought of Jake potentially getting the use of his hands back gives him massive hope. Jake has a strong desire to recover to the highest possible level. He is focused and dedicated to this process. You have done well to choose him for your research. He will make you proud.”

He already has.

Jake and Brady gear

New England Patriots star quarterback Tom Brady signed a ball and jersey for Jake after hearing about the accident


Related Links:

Helping stem cells sleep can boost their power to heal

Mouse muscle

Mighty mouse muscle cells

We are often told that sleep is one of the most important elements of a healthy lifestyle, that it helps in the healing and repair of our heart and blood vessels – among other things.

It turns out that sleep, or something very similar, is equally important for stem cells, helping them retain their power or potency, which is a measure of their effectiveness and efficiency in generating the mature adult cells that are needed to repair damage. Now researchers from Stanford, with a little help from CIRM, have found a way to help stem cells get the necessary rest before kicking in to action. This could pave the way for a whole new approach to treating a variety of genetic disorders such as muscular dystrophy.

Inside out

One problem that has slowed down the development of stem cell therapies has been the inability to manipulate stem cells outside of the body, without reducing their potency. In the body these cells can remain quiescent or dormant for years until called in to action to repair an injury. That’s because they are found in a specialized environment or niche, one that has very particular physical, chemical and biological properties. However, once the stem cells are removed from that niche and placed in a dish in the lab they become active and start proliferating and changing into other kinds of cells.

You might think that’s good, because we want those stem cells to change and mature, but in this case we don’t, at least not yet. We want them to wait till we return them to the body to do their magic. Changing too soon means they have less power to do that.

Researchers at Stanford may have found a way to stop that happening, by creating an environment in the lab that more closely resembles that in the body, so the stem cells remain dormant longer.

As senior author, Thomas Rando, said in a Stanford news release, they have found a way to keep the stem cells dormant longer:

Dr. Thomas Rando, Stanford

Dr. Thomas Rando, Stanford

“Normally these stem cells like to cuddle right up against their native muscle fibers. When we disrupt that interaction, the cells are activated and begin to divide and become less stemlike. But now we’ve designed an artificial substrate that, to the cells, looks, smells and feels like a real muscle fiber. When we also bathe these fibers in the appropriate factors, we find that the stem cells maintain high-potency and regenerative capacity.”

Creating an artificial home

When mouse muscle stem cells (MuSCs) are removed from the mouse they lose their potency after just two days. So the Stanford team set out to identify what elements in the mouse niche helped the cells remain dormant. They identified the molecular signature of the quiescent MuSCs and used that to help screen different compounds to see which ones could help keep those cells dormant, even after they were removed from the mouse and collected in a lab dish.

They whittled down the number of potential compounds involved in this process from 50 to 10, and then tested these in different combinations until they found a formulation that kept the stem cells quiescent for at least 2 days outside of the mouse.

But that was just the start. Next they experimented with different kinds of engineered muscle fibers, to simulate the physical environment inside the mouse niche. After testing various materials, they found that the one with the greatest elasticity was the most effective and used that to create a kind of scaffold for the stem cells.

The big test

The artificial niche they created clearly worked in helping keep the MuSCs in a dormant state outside of the mouse. But would they work when transplanted back into the mouse? To answer this question they tested these stem cells to see if they retained their ability to self-renew and to change into other kinds of cells in the mouse. The good news is they did, and were far more effective at both than MuSCs that had not been stored in the artificial niche.

So, great news for mice but what about people, would this same approach work with human muscle stem cells (hMuSCs)? They next tested this approach using hMuSCs and found that the hMuSCs cultured on the artificial niche were more effective at both self-renewal and retaining their potency than hMuSCs kept in more conventional conditions, at least in the lab.

In the study, published in the journal Nature Biotechnology, the researchers say this finding could help overcome some of the challenges that have slowed down the development of effective therapies:

“Research on MuSCs, hematopoietic stem cells and neural stem cells has shown that very small numbers of quiescent stem cells, even single cells, can replace vast amounts of tissue; culture systems that that maintain stem cell quiescence may allow these findings to be translated to clinical practice. In addition, the possibility of culturing hMuSCs for longer time periods without loss of potency in order to correct mutations associated with genetic disorders, such as muscular dystrophy, followed by transplantation of the corrected cells to replace the pathogenic tissue may enable improved stem cell therapeutics for muscle disorders.”

What’s the big idea? Or in this case, what’s the 19 big ideas?

supermarket magazineHave you ever stood in line in a supermarket checkout line and browsed through the magazines stacked conveniently at eye level? (of course you have, we all have). They are always filled with attention-grabbing headlines like “5 Ways to a Slimmer You by Christmas” or “Ten Tips for Rock Hard Abs” (that one doesn’t work by the way).

So with those headlines in mind I was tempted to headline our latest Board meeting as: “19 Big Stem Cell Ideas That Could Change Your Life!”. And in truth, some of them might.

The Board voted to invest more than $4 million in funding for 19 big ideas as part of CIRM’s Discovery Inception program. The goal of Inception is to provide seed funding for great, early-stage ideas that may impact the field of human stem cell research but need a little support to test if they work. If they do work out, the money will also enable the researchers to gather the data they’ll need to apply for larger funding opportunities, from CIRM and other institutions, in the future

The applicants were told they didn’t have to have any data to support their belief that the idea would work, but they did have to have a strong scientific rational for why it might

As our President and CEO Randy Mills said in a news release, this is a program that encourages innovative ideas.

Randy Mills, Stem Cell Agency President & CEO

Randy Mills, CIRM President & CEO

“This is a program supporting early stage ideas that have the potential to be ground breaking. We asked scientists to pitch us their best new ideas, things they want to test but that are hard to get funding for. We know not all of these will pan out, but those that do succeed have the potential to advance our understanding of stem cells and hopefully lead to treatments in the future.”

So what are some of these “big” ideas? (Here’s where you can find the full list of those approved for funding and descriptions of what they involve). But here are some highlights.

Alysson Muotri at UC San Diego has identified some anti-retroviral drugs – already approved by the Food and Drug Administration (FDA) – that could help stop inflammation in the brain. This kind of inflammation is an important component in several diseases such as Alzheimer’s, autism, Parkinson’s, Lupus and Multiple Sclerosis. Alysson wants to find out why and how these drugs helps reduce inflammation and how it works. If he is successful it is possible that patients suffering from brain inflammation could immediately benefit from some already available anti-retroviral drugs.

Stanley Carmichael at UC Los Angeles wants to use induced pluripotent stem (iPS) cells – these are adult cells that have been genetically re-programmed so they are capable of becoming any cell in the body – to see if they can help repair the damage caused by a stroke. With stroke the leading cause of adult disability in the US, there is clearly a big need for this kind of big idea.

Holger Willenbring at UC San Francisco wants to use stem cells to create a kind of mini liver, one that can help patients whose own liver is being destroyed by disease. The mini livers could, theoretically, help stabilize a person’s own liver function until a transplant donor becomes available or even help them avoid the need for liver transplantation in the first place. Considering that every year, one in five patients on the US transplant waiting list will die or become too sick for transplantation, this kind of research could have enormous life-saving implications.

We know not all of these ideas will work out. But all of them will help deepen our understanding of how stem cells work and what they can, and can’t, do. Even the best ideas start out small. Our funding gives them a chance to become something truly big.


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