Multi-Talented Stem Cells: The Many Ways to Use Them in the Clinic

CIRM kicked off the 2016 International Society for Stem Cell Research (ISSCR) Conference in San Francisco with a public stem cell event yesterday that brought scientists, patients, patient advocates and members of the general public together to discuss the many ways stem cells are being used in the clinic to develop treatments for patients with unmet medical needs.

Bruce Conklin, Gladstone Institutes & UCSF

Bruce Conklin, Gladstone Institutes & UCSF

Bruce Conklin, an Investigator at the Gladstone Institutes and UCSF Professor, moderated the panel of four scientists and three patient advocates. He immediately captured the audience’s attention by showing a stunning video of human heart cells, beating in synchrony in a petri dish. Conklin explained that scientists now have the skills and technology to generate human stem cell models of cardiomyopathy (heart disease) and many other diseases in a dish.

Conklin went on to highlight four main ways that stem cells are contributing to human therapy. First is using stem cells to model diseases whose causes are still largely unknown (like with Parkinson’s disease). Second, genome editing of stem cells is a new technology that has the potential to offer cures to patients with genetic disorders like sickle cell anemia. Third, stem cells are known to secrete healing factors, and transplanting them into humans could be beneficial. Lastly, stem cells can be engineered to attack cancer cells and overcome cancer’s normal way of evading the immune system.

Before introducing the other panelists, Conklin made the final point that stem cell models are powerful because scientists can use them to screen and develop new drugs for diseases that have no treatments or cures. His lab is already working on identifying new drugs for heart disease using human induced pluripotent stem cells derived from patients with cardiomyopathy.

Scientists and Patient Advocates Speak Out

Malin Parmar, Lund University

Malin Parmar, Lund University

The first scientist to speak was Malin Parmar, a Professor at Lund University. She discussed the history of stem cell development for clinical trials in Parkinson’s disease (PD). Her team is launching the first in-human trial for Parkinson’s using cells derived from human pluripotent stem cells in 2016. After Parmar’s talk, John Lipp, a PD patient advocate. He explained that while he might look normal standing in front of the crowd, his PD symptoms vary wildly throughout the day and make it hard for him to live a normal life. He believes in the work that scientists like Parmar are doing and confidently said, “In my lifetime, we will find a stem cell cure for Parkinson’s disease.”

Adrienne Shapiro, Patient Advocate

Adrienne Shapiro, Patient Advocate

The next scientist to speak was UCLA Professor Donald Kohn. He discussed his lab’s latest efforts to develop stem cell treatments for different blood disorder diseases. His team is using gene therapy to modify blood stem cells in bone marrow to treat and cure babies with SCID, also known as “bubble-boy disease”. Kohn also mentioned their work in sickle cell disease (SCD) and in chronic granulomatous disease, both of which are now in CIRM-funded clinical trials. He was followed by Adrienne Shapiro, a patient advocate and mother of a child with SCD. Adrienne gave a passionate and moving speech about her family history of SCD and her battle to help find a cure for her daughter. She said “nobody plans to be a patient advocate. It is a calling born of necessity and pain. I just wanted my daughter to outlive me.”

Henry Klassen (UC Irvine)

Henry Klassen, UC Irvine

Henry Klassen, a professor at UC Irvine, next spoke about blinding eye diseases, specifically retinitis pigmentosa (RP). This disease damages the photo receptors in the back of the eye and eventually causes blindness. There is no cure for RP, but Klassen and his team are testing the safety of transplanting human retinal progenitor cells in to the eyes of RP patients in a CIRM-funded Phase 1/2 clinical trial.

Kristen MacDonald, RP patient

Kristen MacDonald, RP patient

RP patient, Kristen MacDonald, was the trial’s first patient to be treated. She bravely spoke about her experience with losing her vision. She didn’t realize she was going blind until she had a series of accidents that left her with two broken arms. She had to reinvent herself both physically and emotionally, but now has hope that she might see again after participating in this clinical trial. She said that after the transplant she can now finally see light in her bad eye and her hope is that in her lifetime she can say, “One day, people used to go blind.”

Lastly, Catriona Jamieson, a professor and Alpha Stem Cell Clinic director at UCSD, discussed how she is trying to develop new treatments for blood cancers by eradicating cancer stem cells. Her team is conducting a Phase 1 CIRM-funded clinical trial that’s testing the safety of an antibody drug called Cirmtuzumab in patients with chronic lymphocytic leukemia (CLL).

Scientists and Patients need to work together

Don Kohn, Catriona Jamieson, Malin Parmar

Don Kohn, Catriona Jamieson, Malin Parmar

At the end of the night, the scientists and patient advocates took the stage to answer questions from the audience. A patient advocate in the audience asked, “How can we help scientists develop treatments for patients more quickly?”

The scientists responded that stem cell research needs more funding and that agencies like CIRM are making this possible. However, we need to keep the momentum going and to do that both the physicians, scientists and patient advocates need to work together to advocate for more support. The patient advocates in the panel couldn’t have agreed more and voiced their enthusiasm for working together with scientists and clinicians to make their hopes for cures a reality.

The CIRM public event was a huge success and brought in more than 150 people, many of whom stayed after the event to ask the panelists more questions. It was a great kick off for the ISSCR conference, which starts today. For coverage, you can follow the Stem Cellar Blog for updates on interesting stem cell stories that catch our eye.

CIRM Public Stem Cell Event

CIRM Public Stem Cell Event

Stem cell stories that caught our eye: a surprising benefit of fasting, faster way to make iPSCs, unlocking the secret of leukemia cancer 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.

Fasting

Is fasting the fountain of youth?

Among the many insults our bodies endure in old age is a weakened immune system which leaves the elderly more susceptible to infection. Chemotherapy patients also face the same predicament due to the immune suppressing effects of their toxic anticancer treatments. While many researchers aim to develop drugs or cell therapies to protect the immune system, a University of Southern California research report this week suggests an effective alternative intervention that’s startlingly straightforward: fasting for 72 hours.

The study published in Cell Stem Cell showed that cycles of prolonged fasting in older mice led to a decrease in white blood cells which in turn set off a regenerative burst of blood stem cells. This restart of the blood stem cells replenished the immune system with new white blood cells. In a pilot Phase 1 clinical trial, cancer patients who fasted 72 hours before receiving chemotherapy maintained normal levels of white blood cells.

A look at the molecular level of the process pointed to a decrease in the levels of a protein called PKA in stem cells during the fasting period. In a university press release carried by Science Daily, the study leader, Valter Longo, explained the significance of this finding:

“PKA is the key gene that needs to shut down in order for these stem cells to switch into regenerative mode. It gives the ‘okay’ for stem cells to go ahead and begin proliferating and rebuild the entire system. And the good news is that the body got rid of the parts of the system that might be damaged or old, the inefficient parts, during the fasting. Now, if you start with a system heavily damaged by chemotherapy or aging, fasting cycles can generate, literally, a new immune system.”

In additional to necessary follow up studies, the team is looking into whether fasting could benefit other organ systems besides the immune system. If the data holds up, it could be that regular fasting or direct targeting of PKA could put us on the road to a much more graceful and healthier aging process.

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Faster, cheaper, safer way to use iPS cells

Science, like traffic in any major city, never moves quite as quickly as you would like, but now Japanese researchers are teaming up to develop a faster, and cheaper way of using iPSC’s , pluripotent stem cells that are reprogrammed from adult cells, for transplants.

Part of the beauty of iPSCs is that because those cells came from the patient themselves, there is less risk of rejection. But there are problems with this method. Taking adult cells and turning them into enough cells to treat someone can take a long time. It’s expensive too.

But now researchers at Kyoto University and three other institutions in Japan have announced they are teaming up to change that. They want to create a stockpile of iPSCs that are resistant to immunological rejection, and are ready to be shipped out to researchers.

Having a stockpile of ready-to-use iPSCs on hand means researchers won’t have to wait months to develop their own, so they can speed up their work.

Shinya Yamanaka, who developed the technique to create iPSCs and won the Nobel prize for his efforts, say there’s another advantage with this collaboration. In a news article on Nikkei’s Asian Review he said these cells will have been screened to make sure they don’t carry any potentially cancer-causing mutations.

“We will take all possible measures to look into the safety in each case, and we’ll give the green light once we’ve determined they are sound scientifically. If there is any concern at all, we will put a stop to it.”

CIRM is already working towards a similar goal with our iPSC Initiative.

Unlocking the secrets of leukemia stem cells

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Zombies: courtesy “The Walking Dead”

Any article that has an opening sentence that says “Cancer stem cells are like zombies” has to be worth reading. And a report in ScienceMag  that explains how pre-leukemia white blood cell precursors become leukemia cancer stem cells is definitely worth reading.

The article is about a study in the journal Cell Stem Cell by researchers at UC San Diego. The senior author is Catriona Jamieson:

“In this study, we showed that cancer stem cells co-opt an RNA editing system to clone themselves. What’s more, we found a method to dial it down.”

An enzyme called ADAR1 is known to spur cancer growth by manipulating small pieces of genetic material known as microRNA. Jamieson and her team wanted to track how that was done. They discovered it is a cascade of events, and that once the first step is taken a series of others quickly followed on.

They found that when white blood cells have a genetic mutation that is linked to leukemia, they are prone to inflammation. That inflammation then activates ADAR1, which in turn slows down a segment of microRNA called let-7 resulting in increased cell growth. The end result is that the white blood cells that began this cascade become leukemia stem cells and spread an aggressive and frequently treatment-resistant form of the blood cancer.

Having uncovered how ADAR1 works Jamieson and her team then tried to find a way to stop it. They discovered that by blocking the white blood cells susceptibility to inflammation, they could prevent the cascade from even starting. They also found that by using a compound called 8-Aza they could impede ADAR1’s ability to stimulate cell growth by around 40 percent.

Jamieson

Catriona Jamieson – definitely not a zombie

Jamieson says the findings open up all sorts of possibilities:

“Based on this research, we believe that detecting ADAR1 activity will be important for predicting cancer progression. In addition, inhibiting this enzyme represents a unique therapeutic vulnerability in cancer stem cells with active inflammatory signaling that may respond to pharmacologic inhibitors of inflammation sensitivity or selective ADAR1 inhibitors that are currently being developed.”

This wasn’t a CIRM-funded study but we have supported other projects by Dr. Jamieson that have led to clinical trials.

 

 

 

 

New stem cell approach targeting deadly blood cancers

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Every four minutes someone in the US is diagnosed with a blood cancer. It might be lymphoma or leukemia, myeloma or myelodysplastic syndromes (MDS). While we have made great strides in treating some of these over the years, we still have a long way to go. Need proof? Well, every nine minutes someone in the US dies from a blood cancer.

Because of that need, the CIRM Board last week approved $3.5 million to help fund the search for a more effective, more efficient way to treat people suffering from blood cancer.

The Board funded a program by Angiocrine Biosciences, a San Diego-based company that is developing a new method for transplanting cord blood into patients.

Now cord blood transplants have been around for decades and they can be very effective. But they can also cause serious, even life-threatening complications. And they have limitations. For example some cord blood units are small and don’t have as many stem cells as the doctors would like. As a result, patients may need to spend longer in the hospital recovering from the procedure, putting them at increased risk of viral infections or pneumonia. Alternatively, doctors could use more than one cord blood unit for each transplant and while that seems to be an effective alternative, some studies suggest it can also carry an increased risk for serious complications such as Graft-versus-host disease (GVHD) where the newly transplanted cells attack the patient’s body.

To get around these issues, Angiocrine is developing a product called AB-110. This takes stem cells from cord blood, uses a specialized manufacturing facility to expand their numbers and then mixes them with genetically modified endothelial cells, the kind of cell that forms the lining of blood vessels.

It’s hoped that AB-110 will reduce the complications and increase the chances the transplanted cells will successfully engraft, meaning they start growing and creating new, healthy, blood cells.

In a news release CIRM’s President and CEO, C. Randal Mills, PhD, says this program fits in perfectly with our mission of accelerating stem cell treatments to patients with unmet medical needs:

“This project aims to do precisely that, speeding up the body’s ability to create new white blood cells and platelets – both essential qualities when treating deadly diseases like leukemia and lymphoma. Under CIRM 2.0, we are trying to create a pipeline of products that move out of the lab and into clinical trials in people, and we’re hopeful this program will demonstrate it’s potential and get approval from the Food and Drug Administration (FDA) to begin a clinical trial.”

Everyone at Angiocrine and CIRM will work as hard as we can to move this research toward a clinical trial as fast as we can. But in the meantime there are tens of thousands of critically ill people in desperate need of a life-saving transplant.

One way of helping those in need is for new parents to donate their child’s umbilical cord blood to the state’s umbilical cord blood collection program. This is a safe procedure that doesn’t harm the baby but could save someone’s life.

The cord blood program is housed at the UC Davis Institute for Regenerative Cures – a facility CIRM helped build and where we fund many great projects. This program is particularly important because it collects and stores cord blood units that reflect the state’s diverse communities, and that are available to all those in need of a transplant.

The bank also is a rich source of cord blood units for research, particularly for stem cell research, which will hopefully lead to even more effective therapies in the future.

Smoking out Leukemia Cells to Prevent Cancer Relapse

Ninety-five percent of all patients with chronic myeloid leukemia (CML), carry a Frankenstein-like gene, called BCR-ABL, created from an abnormal fusion of two genes normally found on two separate chromosomes. Like a water faucet without a shutoff valve, the resulting mutant protein is stuck in an “on” position and leads to uncontrolled cell division and eventually to CML as well as other blood cancers.

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An oversized bone marrow cell, typical of chronic myeloid leukemia. Credit:  Difu Wu

Gleevec, a revolutionary, targeted cancer drug that specifically blocks the BCR-ABL protein was approved by the FDA in 2001 and doubled 5-year survival rates for CML patients (31 to 59%) over that decade. Still, some patients who are responsive to the Gleevec class of drugs, become resistant to the treatment and suffer a relapse. Up until now, research studies pointed to an accumulation of additional DNA mutations as the driving force behind a rebound of the cancer cells.

But on Monday, a CIRM-funded UC San Diego team reported in PNAS that a reduction in just one protein, called MBNL3, in CML cancer cells activates a cascade of genes normally responsible for the unlimited self-renewing capacity of embryonic stem cells. Much like a researcher can reprogram a skin cell back into an embryonic like state via the induced pluripotent stem cell (iPSC) technique, this finding suggests that CML enhances its ability to spread by exploiting the same cellular reprogramming machinery.

CML is a slowly progressing cancer that initially begins with a chronic phase. At this stage, the cancerous cells, called blast cells, make up less than five percent of cells in the bone marrow. The phase usually lasts several years and is well controlled by drug treatment. A blast crisis phase follows when the blast cells make up 20 to 30% of the blood or bone marrow. At this stage, the patient’s condition deteriorates as symptoms like anemia and frequent infections worsen.

The UCSD team, led by Catriona Jamieson, director of Stem Cell Research at Moores Cancer Center, did a comparative analysis of CML patient samples and found that a reduction of MBNL3, a RNA binding protein, corresponded with CML progression from the chronic to blast phase. If you took intro biology in high school or college, you may recall that RNA acts as a messenger molecule critical to the translation of DNA’s genetic code into proteins. Some splicing and trimming of the RNA molecule occurs to prep it for this translation process. It turns out the decrease in MBNL3 in blast phase cells frees up stretches of RNA that leads to alternate splicing and, in turn, alternate forms of a given protein.

The study showed that in response to the decrease of MBNL3, an alternate form of the protein CD44, aptly named CD44 variant 3 (CD44v3), is increased in CML blast phase cells compared with chronic phase cells. Artificially over producing CD44v3 increased the activity of SOX2 and OCT4, two genes that are critical for maintaining the properties of embryonic stem cells. Genes involved with homing blood cells to the bone marrow were also upregulated.

Put together, these data suggest that this alternate RNA splicing not only helps CML blast phase cells preserve stem cell-like qualities, but it also helps sequester them in the bone marrow. Other studies have shown that the BCR-ABL protein inhibitor drugs are not effective in eradicating blast phase cells in the bone marrow, perhaps the reason behind relapse in some CML patients.

To try to smoke out these hiding blast phase cells in mouse CML studies, the team tested a combination treatment of a CD44 inhibitor along with the BCR-ABL inhibitor. While either treatment alone effectively removed the CML blast phase cells from the spleen and blood, only the combination significantly reduced survival of the cells in the bone marrow.

This tantalizing result has motivated the Jamieson team to pursue the clinical development of a CD44 blocking antibody with combination with the existing BCR-ABL inhibitors. As reported by Bradley Fikes in a San Diego Union Tribune story, the CD44 blocking antibody was not stable so more work is still needed to generate a new antibody.

But the goal remains the same as Jamieson mentions in a UCSD press release:

“If we target embryonic versions of proteins that are re-expressed by cancer, like CD44 variant 3, with specific antibodies together with tyrosine kinase [for example, BCR-ABL] inhibitors, we may be able to circumvent cancer relapse – a leading cause of cancer-related mortality.”

 

 

 

 

 

Holy Guacamole! Nutrient in Avocado Kills Cancer Stem Cells

Over four billion avocados were sold last year in the U.S. and for good reason – they’re so darn delicious and good for you too (wish you could say the same for doughnuts). Often called the world’s perfect food, avocados are high in fiber and packed with vitamins. Even the fat they contain is the healthy kind that’s associated with lower cholesterol levels and healthier hearts. As if the news couldn’t get any better, research published this week now suggests that a nutrient found in avocado can kill cancer stem cells – a cell type thought to be the source of a cancer’s unlimited growth and spread.

avocado, the world's perfect food

avocado, the world’s perfect food

The study, reported in Cancer Research by a Canadian research team at the University of Waterloo, focuses on a particularly deadly form of blood cancer called acute myeloid leukemia (AML). Often striking adults over 65, AML has a poor prognosis with only 10% survival after five years for this age group.

The cancer is caused by rapid, abnormal growth of white blood cells in the bone marrow that eventually crowds out normal blood cells leading to a deterioration of vital functions of the blood like carrying oxygen to the body. Chemotherapy or bone marrow transplants are standard treatments but unfortunately, even when successful, a majority of AML patients will relapse.

Though they make up a tiny portion of the leukemia, cancer stem cells are thought to be the main culprits behind AML relapse due to their stem cell-like ability for unlimited growth. The research team identified a nutrient in avocados called avocatin B with the ability to kill AML cancer stem cells. The killing mechanism of avocatin B was pinpointed to its disruption of the mitochondria, the cell’s energy “factory”, in leukemia cells, which led to cell death. As senior author Professor Paul Spagnuolo points out in a university press release, this cancer killing property of avocatin B promises to have limited side effects:

“We’ve performed many rounds of testing to determine how this new drug works at a molecular level and confirmed that it targets [cancer] stem cells selectively, leaving healthy cells unharmed.”

Now, before you rush out to the grocery store and stock up on nothing but avocados, keep in mind this is a preliminary study in petri dishes. Extensive follow up studies will be required before testing in humans can begin. Also, it’s not clear if eating avocado or an avocado extract would be a sufficient method of delivering avocatin B to keep cancer stem cells at bay. It’s more likely that avocatin B would be purified and provided as a food nutrient drug or a so-called nutraceutical:

“Extracts are less refined. The contents of an extract can vary from plant to plant and year to year, depending on lots of factors – on the soil, the location, the amount of sunlight, the rain,” explains Spagnuolo. “Evaluating a nutraceutical as a potential clinical drug requires in-depth evaluation at the molecular level. This approach provides a clearer understanding of how the nutraceutical works, and it means we can reproduce the effects more accurately and consistently. This is critical to safely translating our lab work into a reliable drug that could be used in oncology clinics.”

I look forward to following this story in the months and years to come with the hope that families devastated by an AML diagnosis will have more treatment options.

Goodnight, Stem Cells: How Well Rested Cells Keep Us Healthy

Plenty of studies show that a lack of sleep is nothing but bad news and can contribute to a whole host of health problems like heart disease, poor memory, high blood pressure and obesity.

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Even stem cells need rest to stay healthy

In a sense, the same holds true for the stem cells in our body. In response to injury, adult stem cells go to work by dividing and specializing into the cells needed to heal specific tissues and organs. But they also need to rest for long-lasting health. Each cell division carries a risk of introducing DNA mutations—and with it, a risk for cancer. Too much cell division can also deplete the stem cell supply, crippling the healing process. So it’s just as important for the stem cells to assume an inactive, or quiescent, state to maintain their ability to mend the body. Blood stem cells for instance are mostly quiescent and only divide about every two months to renew their reserves.

Even though the importance of this balance is well documented, exactly how it’s achieved is not well understood; that is, until now. Earlier this week, a CIRM-funded research team from The Scripps Research Institute (TSRI) reported on the identification of an enzyme that’s key in controlling the work-rest balance in blood stem cells, also called hematopoietic stem cells (HSCs). Their study, published in the journal Blood, could point the way to drugs that treat anemias, blood cancers, and other blood disorders.

Previous studies in other cell types suggested that this key enzyme, called ItpkB, might play a role in promoting a rested state in HSCs. Senior author Karsten Sauer explained their reasoning for focusing on the enzyme in a press release:

“What made ItpkB an attractive protein to study is that it can dampen activating signaling in other cells. We hypothesized that ItpkB might do the same in HSCs to keep them at rest. Moreover, ItpkB is an enzyme whose function can be controlled by small molecules. This might facilitate drug development if our hypothesis were true.”

Senior author Karsten Sauer is an associate professor at The Scripps Research Institute.

Senior author Karsten Sauer is an associate professor at The Scripps Research Institute.

To test their hypothesis, the team studied HSCs in mice that completely lacked ItpkB. Sure enough, without ItpkB the HSCs got stuck in the “on” position and continually multiplied until the supply of HSCs stores in the bone marrow were exhausted. Without these stem cells, the mice could no longer produce red blood cells, which deliver oxygen to the body or white blood cells, which fight off infection. As a result the animals died due to severe anemia and bone marrow failure. Sauer used a great analogy to describe the result:

“It’s like a car—you need to hit the gas pedal to get some activity, but if you hit it too hard, you can crash into a wall. ItpkB is that spring that prevents you from pushing the pedal all the way through.”

With this new understanding of how balancing stem cell activation and deactivation works, Sauer and his team have their sights set on human therapies:

“If we can show that ItpkB also keeps human HSCs healthy, this could open avenues to target ItpkB to improve HSC function in bone marrow failure syndromes and immunodeficiencies or to increase the success rates of HSC transplantation therapies for leukemias and lymphomas.”

10 Years/10 Therapies: 10 Years after its Founding CIRM will have 10 Therapies Approved for Clinical Trials

In 2004, when 59 percent of California voters approved the creation of CIRM, our state embarked on an unprecedented experiment: providing concentrated funding to a new, promising area of research. The goal: accelerate the process of getting therapies to patients, especially those with unmet medical needs.

Having 10 potential treatments expected to be approved for clinical trials by the end of this year is no small feat. Indeed, it is viewed by many in the industry as a clear acceleration of the normal pace of discovery. Here are our first 10 treatments to be approved for testing in patients.

HIV/AIDS. The company Calimmune is genetically modifying patients’ own blood-forming stem cells so that they can produce immune cells—the ones normally destroyed by the virus—that cannot be infected by the virus. It is hoped this will allow the patients to clear their systems of the virus, effectively curing the disease.

Spinal cord injury patient advocate Katie Sharify is optimistic about the latest clinical trial led by Asterias Biotherapeutics.

Spinal cord injury patient advocate Katie Sharify is optimistic about the clinical trial led by Asterias Biotherapeutics.

Spinal Cord Injury. The company Asterias Biotherapeutics uses cells derived from embryonic stem cells to heal the spinal cord at the site of injury. They mature the stem cells into cells called oligodendrocyte precursor cells that are injected at the site of injury where it is hoped they can repair the insulating layer, called myelin, that normally protects the nerves in the spinal cord.

Heart Disease. The company Capricor is using donor cells derived from heart stem cells to treat patients developing heart failure after a heart attack. In early studies the cells appear to reduce scar tissue, promote blood vessel growth and improve heart function.

Solid Tumors. A team at the University of California, Los Angeles, has developed a drug that seeks out and destroys cancer stem cells, which are considered by many to be the reason cancers resist treatment and recur. It is believed that eliminating the cancer stem cells may lead to long-term cures.

Leukemia. A team at the University of California, San Diego, is using a protein called an antibody to target cancer stem cells. The antibody senses and attaches to a protein on the surface of cancer stem cells. That disables the protein, which slows the growth of the leukemia and makes it more vulnerable to other anti-cancer drugs.

Sickle Cell Anemia. A team at the University of California, Los Angeles, is genetically modifying a patient’s own blood stem cells so they will produce a correct version of hemoglobin, the oxygen carrying protein that is mutated in these patients, which causes an abnormal sickle-like shape to the red blood cells. These misshapen cells lead to dangerous blood clots and debilitating pain The genetically modified stem cells will be given back to the patient to create a new sickle cell-free blood supply.

Solid Tumors. A team at Stanford University is using a molecule known as an antibody to target cancer stem cells. This antibody can recognize a protein the cancer stem cells carry on their cell surface. The cancer cells use that protein to evade the component of our immune system that routinely destroys tumors. By disabling this protein the team hopes to empower the body’s own immune system to attack and destroy the cancer stem cells.

Diabetes. The company Viacyte is growing cells in a permeable pouch that when implanted under the skin can sense blood sugar and produce the levels of insulin needed to eliminate the symptoms of diabetes. They start with embryonic stem cells, mature them part way to becoming pancreas tissues and insert them into the permeable pouch. When transplanted in the patient, the cells fully develop into the cells needed for proper metabolism of sugar and restore it to a healthy level.

HIV/AIDS. A team at The City of Hope is genetically modifying patients’ own blood-forming stem cells so that they can produce immune cells—the ones normally destroyed by the virus—that cannot be infected by the virus. It is hoped this will allow the patients to clear their systems of the virus, effectively curing the disease

Blindness. A team at the University of Southern California is using cells derived from embryonic stem cell and a scaffold to replace cells damaged in Age-related Macular Degeneration (AMD), the leading cause of blindness in the elderly. The therapy starts with embryonic stem cells that have been matured into a type of cell lost in AMD and places them on a single layer synthetic scaffold. This sheet of cells is inserted surgically into the back of the eye to replace the damaged cells that are needed to maintain healthy photoreceptors in the retina.

Stories of Hope: Leukemia

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.

Stem cells create life. But if things go wrong, they can also threaten it. Theresa Blanda found that out the hard way. Fortunately for her, CIRM-funded research helped her fight this threat, and get her life back.

Theresa's battle with leukemia took a happier turn after entering into a stem cell-based clinical trial.

Theresa’s battle with leukemia took a happier turn after entering into a stem cell-based clinical trial.

In the first few days of human development embryonic stem cells are a blank slate; they don’t yet have a special, defined role, but have potential. The potential to turn into the cells that make up our kidneys, heart, brain, every other organ and every tissue in our body. Because of this flexibility, stem cells have shown great promise as a way to regenerate dead, diseased or injured tissue to treat many life-threatening or chronic conditions.

But some studies have suggested a secret, darker side to stem cells—so-called cancer stem cells. Like their embryonic cousins, these cells have the ability to both self-renew— to divide and make more copies of themselves – and specialize into other cell types. Many researchers believe they can serve as a reservoir for cancer, constantly reinvigorating tumors, helping them spread throughout the body. To complicate matters, these slow-growing cells are often impervious to cancer therapies, enabling them to survive chemotherapy.

For Theresa Blanda, cancer stem cells were dragging her down a slippery slope towards disease and possibly death. In 2003, she was diagnosed with polycythemia vera (CV), which causes the body to produce too many red blood cells. As sometimes happens with CV patients, her body began producing too many white blood cells as well. Eventually, she developed an even more serious condition, myelofibrosis, a form of bone marrow scarring that results in an enlarged spleen, bone pain, knee swelling and other debilitating symptoms.

“You couldn’t even breathe my way or I’d bruise,” says Theresa. “I didn’t think I was going to make it.”

Her doctors wanted to do a bone marrow transplant, but were having difficulty finding the right donor. “Finally, I just asked if there was some kind of clinical trial that could help me,” says Theresa.

Fortunately, there was.

The Root Cause
At UC San Diego’s Moores Cancer Center, Catriona Jamieson, M.D., Ph.D., had made a discovery that would have a big impact on Theresa’s health. In research funded in part by CIRM, Jamieson found a key mutation in blood-forming stem cells. Specifically, a mutation in a gene called JAK2 was being passed on to Theresa’s entire blood system, causing CV and myelofibrosis. Without effective treatment, her condition could have progressed into acute myeloid leukemia, a blood cancer with a very poor survival rate.

“These malignant stem cells create an inhospitable environment for regular stem cells, suppressing normal blood formation,” says Jamieson. “We needed to get rid of these mutated stem cells so the normal ones could breathe a sigh of relief.”

The answer was a JAK2 inhibitor being developed by San Diego-based TargeGen. Though the trial had already started, they made room for Theresa and the results were amazing. Within weeks, her discomfort had faded, her spleen had returned to normal and she was back at work.

“In a month or two I was feeling pretty good,” says Theresa. “I could climb stairs and the swelling in my knee had gone down.”

She continued on the drug for five years but safety issues forced the trial to be suspended. But the work continues. With continued support from CIRM, Jamieson and others are investigating new JAK2 inhibitors, and other alternatives, to help myelofibrosis patients.

“Because of CIRM funding, we’ve managed to develop a number of agents that have gone into clinical trials,” says Jamieson. “That means patients have lived to hold their grandchildren, attend their mom’s hundredth birthday party and live fruitful lives.”

For more information about CIRM-funded leukemia research, visit our Leukemia Fact Sheet. You can read more about Theresa’s Story of Hope on our website.

Revealing the Invisible: Scientists Uncover the Secret Ingredient to Making Blood-Forming Stem Cells

They are among the most versatile types of stem cell types in the body. They live inside bone marrow and in the blood of the umbilical cord. They can be used to treat deadly cancers such as leukemia (Leukemia Fact Sheet) as well as many blood disorders. But no one really understood the details of how they were made.

How are blood stem cells made? Australian scientists have uncovered a missing ingredient.

How are blood stem cells made? Australian scientists have uncovered a missing ingredient.

That is, until scientists at the Australian Regenerative Medicine Institute devised an ingenious way to view the formation of these hematopoetic stem cells (HSC’s) in unprecedented detail. And in so doing, found the missing ingredient that may make it possible to grow fully functioning versions of these cells in the lab—opening the door to treating a wide range of blood and immune disorders. Attempts to grow these in the past have resulted in immature versions more like those found in a fetus than those in an adult.

One of the study’s senior authors, Dr. Peter Currie, even goes so far as to say this discovery represents a ‘Holy Grail’ for the field. As he explained in today’s news release:

“HSCs are one of the best therapeutic tools at our disposal because they can make any blood cell in the body. Potentially we could use these cells in may more ways than current transplantation strategies to treat serious blood disorders and diseases, but only if we can figure out how they are generated in the first place.”

Fortunately, this new study—published today in the journal Nature—brings researchers closer to that goal.

Using high-resolution microscopic imaging techniques, Currie and his team filmed the development of a zebra fish embryo—with a particular focus on HSCs. When they played back the video, the team saw something that no one had noticed before. In order for HSCs to develop properly, they needed a little support from another cell type known as endotomes. As Currie explained:

“Endotome cells act like a comfy sofa for pre-HSCs to snuggle into, helping them progress to become fully fledged [HSCs]. Not only did we identify some of the cells and signals required for HSC formation, we also pinpointed the genes required for endotome formation in the first place.”

It appears that this unique relationship between endotomes and HSCs is key to HSC formation, a process that had for so long evaded researchers. But armed with this newfound knowledge, the team could one day produce different types of blood cells ‘on demand’—and potentially treat many types of blood disorders. This has been such a tough nut to crack with such great potential CIRM convened an international panel of experts to produce a whitepaper on the issue.

The team’s immediate next steps, according to Currie, are to pinpoint the molecular switches themselves (within endotomes and HSCs) that trigger the production of these stem cells. And while these results are preliminary, he is cautiously optimistic about the potential power to treat a variety of illnesses:

“Potentially, it’s imaginable that you could even correct genetic defects in cells and then transplant them back into the body.”

Clever Stem Cells Withstand Chemo Drug’s Harmful Side Effects

For some conditions, it seem that the treatment can cause almost as many problems as than the disease itself. That’s often the case with some forms of cancer, such as acute lymphoblastic leukemia.

The most common type of cancer to affect children, treatment usually involves chemotherapy with the drug methotrexate (MTX). And, while effective at destroying the deadly cancer cells circulating in the patients’ blood, it also does significant damage to another part of the body: the bone.

Scientists have long sought a method that helps patients recover more quickly from the harmful effects of chemotherapy.

Scientists have long sought a method that helps patients recover more quickly from the harmful effects of chemotherapy.

But new research from Brown University’s Dr. Eric Darling and his team has found that not all types of bone cells are equally at risk of being damaged by MTX. In fact, one type may actually be impervious to the drug’s negative effects. These findings, published last week in the journal Experimental Cell Research, are especially important as doctors look to ways that help the youngest, most vulnerable cancer patients heal faster after treatment—regaining bone strength that can take them into a healthy adulthood.

As Olivia Beane, a graduate student in the Darling Lab and the lead author of this paper, explained in a news release:

“Kids undergo chemotherapy at such an important time when they should be growing, but instead they are introduced to this very harsh environment where bone cells are damaged with these drugs. If we found a stem cell that was resistant to the chemotherapeutic agent and could promote bone growth by becoming bone itself, then maybe they wouldn’t have these issues.”

The cell type Beane is referring to are called adipose-derived stem cells, or ASCs, which normally mature from this early, stem cell state into several types of mature cells, including bone tissue. Initially, Beane had been researching the basic properties of ASCs. But during her experiments she discovered that ASCs, unlike other stem cell types that mature into bone, appear to survive MTX. Now they just needed to understand why.

Further experiments revealed the underlying strengths of ASCs in resisting MTX’s effects. Normally, MTX works by binding to and shutting down a protein in the cell called dihydrofolate reductase, which is normally involved in synthesizing DNA. With DNA production shut down, cells can’t divide and multiply—which is great for killing harmful cancer cells, but potentially harmful as it can also destroy cells it shouldn’t.

However, ASCs are a little bit different. When coming into contact with MTX, these cells ramp up the DNA-promoting dihydrofolate reductase, producing more than enough to overcome a normal dose of MTX.

This discovery has raised some intriguing possibilities for treating MTX’s side effects. As Darling explained:

“Chemotherapies do a great job of killing cells and killing the cancer, and that’s what you want. But then there is a stage after that where you need to do recovery and regeneration.”

And while the results of this study are preliminary, the researchers are cautiously optimistic that the MTX-resistant properties of ASCs could be the key to fast tracking recovery times.

The first step, Darling adds, is to save a life. And MTX has done that for countless children afflicted by cancer. But the cost of saving that life should also be taken into account—so that these children who have already been through so much may one day not need to worry about long, healthy lives as they mature into adults.

Want to learn more about how CIRM-funded researchers are developing new tools to fight all types of leukemia? Check out our Leukemia Fact Sheet.

Anne Holden