California gets first royalty check from Stem Cell Agency investments

COH image

CIRM recently shared in a little piece of history. The first royalty check, based on CIRM’s investment in stem cell research, was sent to the California State Treasurer’s office from City of Hope. It’s the first of what we hope will be many such checks, helping repay, not just the investment the state made in the field, but also the trust the voters of California showed when they created CIRM.

The check, for $190,345.87, was for a grant we gave City of Hope back in 2012 to develop a therapy for glioblastoma, one of the deadliest forms of brain cancer. That has led to two clinical trials and a number of offshoot inventions that were subsequently licensed to a company called Mustang Bio.

Christine Brown, who is now the principal investigator on the project, is quoted in a front page article in the San Francisco Chronicle, on the significance of the check for California:

“This is an initial payment for the recognition of the potential of this therapy. If it’s ultimately approved by the FDA as a commercial product, this could be a continued revenue source.”

In the same article, John Zaia, Director of the City of Hope Alpha Stem Cell Clinic, says this also reflects the unique nature of CIRM:

“I think this illustrates that a state agency can actually fund research in the private community and get a return on its investment. It’s something that’s not done in general by other funding agencies such as the National Institutes of Health, and this is a proof of concept that it can work.”

Maria Millan, CIRM’s President & CEO, says the amount of the payment is not the most significant part of this milestone – after all CIRM has invested more than $2.5 billion in stem cell research since 2004. She says the fact that we are starting to see a return on the investment is important and reflects some of the many benefits CIRM brings to the state.

“It’s a part of the entire picture of the return to California. In terms of what it means to the health of Californians, and access to these transformative treatments, as well as the fact that we are growing an industry.”

 

Novel approach to slowing deadly brain cancer stem cells may lead to new treatments

Glioblastoma, a form of brain cancer, is one of the most dreaded cancer diagnoses. Standard radiation and chemotherapy treatments for glioblastoma almost always prove ineffective because of the cancer’s ability to grow back. With their unlimited potential to self-renew, cancer stem cells within the brain tumor are thought to be responsible for its aggressive reoccurrence. Not surprisingly, researchers looking to develop more effective therapies are focused on trying to better understand the biology of these cancer stem cells in order to exploit their vulnerabilities.

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MRI image of high grade glioma brain tumor (white mass on left). Image: Wikipedia

This week, the Dartmouth-Hitchcock Medical Center reports that a research team led by Damian A. Almiron Bonnin has identified a cell signal that the brain cancer stem cells rely on to resist standard treatments and to regrow. They also showed that drugs which interrupt this signal reduced tumor growth in animal studies.

Because if its aggressive growth, the cells within the glioblastoma eventually become starved for oxygen or, in scientific lingo, they become hypoxic. The presence of hypoxia in brain tumors is actually predictive of a poor prognosis in affected patients. A protein called hypoxia-inducible factor (HIF) becomes activated in these low oxygen conditions and helps the cancer stem cells to survive and continue to grow. The research team found that HIF carries out this function by triggering a cascade of cell activity that leads to the secretion of a protein called VEGF out into the microenvironment of the tumor. As secreted VEGF spreads through the tumor, it stimulates new blood vessel growth which is key to the tumor’s survival by nourishing the tumor with oxygen and nutrients.

Adding drugs that block a cell’s ability to release proteins, led to a reduction in glioblastoma tumor growth both in petri dishes and in animal studies. With these results, published in Oncogene, Dr. Almiron Bonnin’s team is performing the necessary preclinical studies that could lead to testing this novel strategy in patients. He summed this effort in a press release:

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Damian Almiron Bonnin

“Being able to target the cancer stem cells within these tumors, like we did here, could potentially improve response to current chemotherapies and prevent recurrences, which would translate into an increase in patient survival rates.”

 

Stem Cell Stories That Caught Our Eye: Halting Brain Cancer, Parkinson’s disease and Stem Cell Awareness Day

Stopping brain cancer in its tracks.

Experiments by a team of NIH-funded scientists suggests a potential method for halting the expansion of certain brain tumors.Michelle Monje, M.D., Ph.D., Stanford University.

Scientists at Stanford Medicine discovered that you can halt aggressive brain cancers called high-grade gliomas by cutting off their supply of a signaling protein called neuroligin-3. Their research, which was funded by CIRM and the NIH, was published this week in the journal Nature. 

The Stanford team, led by senior author Michelle Monje, had previously discovered that neuroligin-3 dramatically spurred the growth of glioma cells in the brains of mice. In their new study, the team found that removing neuroligin-3 from the brains of mice that were transplanted with human glioma cells prevented the cancer cells from spreading.

Monje explained in a Stanford news release,

“We thought that when we put glioma cells into a mouse brain that was neuroligin-3 deficient, that might decrease tumor growth to some measurable extent. What we found was really startling to us: For several months, these brain tumors simply didn’t grow.”

The team is now exploring whether targeting neuroligin-3 will be an effective therapeutic treatment for gliomas. They tested two inhibitors of neuroligin-3 secretion and saw that both were effective in stunting glioma growth in mice.

Because blocking neuroligin-3 doesn’t kill glioma cells and gliomas eventually find ways to grow even in the absence of neuroligin-3, Monje is now hoping to develop a combination therapy with neuroligin-3 inhibitors that will cure patients of high-grade gliomas.

“We have a really clear path forward for therapy; we are in the process of working with the company that owns the clinically characterized compound in an effort to bring it to a clinical trial for brain tumor patients. We will have to attack these tumors from many different angles to cure them. Any measurable extension of life and improvement of quality of life is a real win for these patients.”

Parkinson’s Institute CIRM Research Featured on KTVU News.

The Bay Area Parkinson’s Institute and Clinical Center located in Sunnyvale, California, was recently featured on the local KTVU news station. The five-minute video below features patients who attend the clinic at the Parkinson’s Institute as well as scientists who are doing cutting edge research into Parkinson’s disease (PD).

Parkinson’s disease in a dish. Dopaminergic neurons made from PD induced pluripotent stem cells. (Image courtesy of Birgitt Schuele).

One of these scientists is Dr. Birgitt Schuele, who recently was awarded a discovery research grant from CIRM to study a new potential therapy for Parkinson’s using human induced pluripotent stem cells (iPSCs) derived from PD patients. Schuele explains that the goal of her team’s research is to “generate a model for Parkinson’s disease in a dish, or making a brain in a dish.”

It’s worth watching the video in its entirety to learn how this unique institute is attempting to find new ways to help the growing number of patients being diagnosed with this degenerative brain disease.

Click on photo to view video.

Mark your calendars for Stem Cell Awareness Day!

Every year on the second Wednesday of October is Stem Cell Awareness Day (SCAD). This is a day that our agency started back in 2009, with a proclamation by former California Mayor Gavin Newsom, to honor the important accomplishments made in the field of stem cell research by scientists, doctors and institutes around the world.

This year, SCAD is on October 11th. Our Agency will be celebrating this day with a special patient advocate event on Tuesday October 10th at the UC Davis MIND Institute in Sacramento California. CIRM grantees Dr. Jan Nolta, the Director of UC Davis Institute for Regenerative Cures, and Dr. Diana Farmer, Chair of the UC Davis Department of Surgery, will be talking about their CIRM-funded research developing stem cell models and potential therapies for Huntington’s disease and spina bifida (a birth defect where the spinal cord fails to fully develop). You’ll also hear an update on  CIRM’s progress from our President and CEO (Interim), Maria Millan, MD, and Chairman of the Board, Jonathan Thomas, PhD, JD. If you’re interested in attending this event, you can RSVP on our Eventbrite Page.

Be sure to check out a list of other Stem Cell Awareness Day events during the month of October on our website. You can also follow the hashtag #StemCellAwarenessDay on Twitter to join in on the celebration!

One last thing. October is an especially fun month because we also get to celebrate Pluripotency Day on October 4th. OCT4 is an important gene that maintains stem cell pluripotency – the ability of a stem cell to become any cell type in the body – in embryonic and induced pluripotent stem cells. Because not all stem cells are pluripotent (there are adult stem cells in your tissues and organs) it makes sense to celebrate these days separately. And who doesn’t love having more reasons to celebrate science?

Taming the Zika virus to kill cancer stem cells that drive lethal brain tumor

An out of control flame can be very dangerous, even life-threatening. But when harnessed, that same flame sustains life in the form of warm air, a source of light, and a means to cook.

A similar duality holds true for viruses. Once it infects the body, a virus can replicate like wildfire and cause serious illness and sometimes death. But in the lab, researchers can manipulate viruses to provide an efficient, harmless method to deliver genetic material into cells, as well as to prime the immune system to protect against future infections.

In a Journal of Experimental Medicine study published this week, researchers from the University of Washington, St. Louis and UC San Diego also show evidence that a virus, in this case the Zika virus, could even be a possible therapy for a hard-to-treat brain cancer called glioblastoma.

Brain cancer stem cells (left) are killed by Zika virus infection (image at right shows cells after Zika treatment). Image: Zhe Zhu, Washington U., St. Louis.

Recent outbreaks of the Zika virus have caused microcephaly during fetal development. Babies born with microcephaly have a much smaller than average head size due to a lack of proper brain development. Children born with this condition suffer a wide range of devastating symptoms like seizures, difficulty learning, and movement problems just to name a few. In the race to understand the outbreak, scientists have learned that the Zika virus induces microcephaly by infecting and killing brain stem cells, called neural progenitors, that are critical for the growth of the developing fetal brain.

Now, glioblastoma tumors contain a small population of cells called glioblastoma stem cells (GSCs) that, like neural progenitors, can lay dormant but also make unlimited copies of themselves.  It’s these properties of glioblastoma stem cells that are thought to allow the glioblastoma tumor to evade treatment and grow back. The research team in this study wondered if the Zika virus, which causes so much damage to neural progenitors in developing babies, could be used for good by infecting and killing cancer stem cells in glioblastoma tumors in adult patients.

To test this idea, the scientists infected glioblastoma brain tumor samples with Zika and showed that the virus spreads through the cells but primarily kills off the glioblastoma stem cells, leaving other cells in the tumor unscathed. Since radiation and chemotherapy are effective at killing most of the tumor but not the cancer stem cells, a combination of Zika and standard cancer therapies could provide a knockout punch to this aggressive brain cancer.

Even though Zika virus is much more destructive to the developing fetal brain than to adult brains, it’s hard to imagine the US Food and Drug Administration ever approving the injection of a dangerous virus into the site of a glioblastoma tumor. So, the scientists genetically modified the Zika virus to make it more sensitive to the immune system’s first line of defense called the innate immunity. With just the right balance of genetic alterations, it might be possible to retain the Zika virus’ ability to kill off cancer stem cells without causing a serious infection.

The results were encouraging though not a closed and shut case: when glioblastoma cancer stem cells were infected with these modified Zika virus strains, the virus’ cancer-killing abilities were weaker than the original Zika strains but still intact. Based on these results, co-senior author and WashU professor, Dr. Michael S. Diamond, plans to make more tweaks to the virus to harness it’s potential to treat the cancer without infecting the entire brain in the process.

“We’re going to introduce additional mutations to sensitize the virus even more to the innate immune response and prevent the infection from spreading,” said Diamond in a press release. “Once we add a few more changes, I think it’s going to be impossible for the virus to overcome them and cause disease.”

 

Brain stem cells unintentionally talk with brain tumors, allowing their spread

A stem cell’s capacity to lay quiet and, when needed, to self-renew plays a key role in restoring and maintaining the health of our organs. Unfortunately, cancer stem cells possess that same property allowing them to evade radiation and chemotherapy treatments which leads to tumor regrowth. And a CIRM-funded study published today in Cell shows the deviousness of these cancer cells goes even further. The Stanford research team behind the study found evidence that brain stem cells, which normally guide brain development and maintenance, unintentionally communicate with brain cancer cells in deadly tumors, called gliomas, providing them a means to invade other parts of the brain. But the silver lining to this scary insight is that it may lead to new treatment options for patients.

High grade gliomas do not end well
The most aggressive forms of glioma are called high grade gliomas and they carry devastating prognoses. For instance, the most common form of these tumors in children has a median survival of just 9 months with a 5-year survival of less than 1%. Surgery or anti-cancer therapies may help for a while but the tumor inevitably grows back.

MRI image of high grade glioma brain tumor (white mass on left). Image: Wikipedia

Researchers have observed that gliomas typically originate in the brain stem and very often invade a brain stem cell-rich area, called the subventrical zone (SVZ), that provides a space for the therapy-resistant cancer stem cells to hole up. This path of tumor spread is associated with a shorter time to relapse and poorer survival but the exact mechanism wasn’t known. The Stanford team hypothesized that SVZ brain stem cells release some factor that attracts the gliomas to preferentially invade that part of the brain.

To test this chemo-attraction idea, they mimicked cancer cell invasion in a specialized, dual compartment petri dish called a Boyden chamber. In the bottom compartment, they placed the liquid food, or media, that SVZ brain stem cells had been grown in. On the upper compartment, they placed the cancerous glioma cells. A porous, gelatin membrane between the two compartments acts as a barrier but allows the cells to receive signals from the lower compartment and migrate down into the media if a chemoattractant is present. And that’s what they saw: a significant glioma cell migration through the gelatin toward the brain stem cell media.

Boyden chamber assay. Image: Integr. Biol., 2009,1, 170-181

Pleiotrophin: an unintentional communicator with brain cancer cells
Something or somethings in the SVZ brain stem cell media had to be attracting the glioma cells. So, the Stanford team analyzed the composition of the media and identified four proteins that, when physically complexed together, had the same chemo-attraction ability as the media. They were pleased to find that one of the four proteins is pleiotrophin which is known to not only play a role in normal brain development and regeneration but also to increase glioma cell migration. And in this study, they showed that higher levels of pleiotrophin are present in the SVZ brain stem cell area compared to other regions of the brain. They went on to show that blocking the production of pleiotrophin in mice reduced the invasion of glioma cells into the SVZ region. This result suggests that blocking the release of pleiotrophin by brain stem cells in the SVZ could help prevent or slow down the spread of glioma in patients’ brains without the need of irradiating this important part of the brain.

The silver lining: hsp90 inhibitors have therapeutic promise

Michelle Monje, MD, PhD

To further explore this potential therapeutic approach, the team examined hsp90, one of the other three proteins complexed with pleiotrophin. Though it doesn’t have chemoattractant properties, it still is a necessary component and may act to stabilize pleiotrophin. It also turns out that inhibitors for hsp90 have already been developed in the clinic for treating various cancers. When the researchers in this study blocked hsp90 production in the SVZ region of mice, they observed a reduced invasion of glioma cells. Though clinical grade hsp90 inhibitors exist, team lead  Michelle Monje, MD, PhD – assistant professor of neurology, Stanford University – tells me that some tweaking of these drugs will be necessary to reach gliomas:

“Our challenge is to find an hsp90 inhibitor that penetrates the brain at effective concentrations.”

Once they find that inhibitor, it could provide new options, and hope, for people diagnosed with this dreadful cancer.

Genetically engineered immune cells melt away deadly brain tumors

MRI scan of patient with glioblastoma tumor. (wikicommons)

MRI scan of patient with glioblastoma. (wikicommons)

Cancers come in many different forms. Some are treatable if caught early and other aren’t. One of the most deadly types of cancers are glioblastomas – a particularly aggressive form of brain tumor.  Patients diagnosed with glioblastoma have an average life expectancy of 12-15 months and there is no cure or effective treatment that extends life.

While a glioblastoma diagnosis has pretty much been a death sentence, now there could be a silver lining to this deadly, fast-paced disease. Last week, scientists from the City of Hope in southern California reported in the New England Journal of Medicine, a new cell-based therapy that melted away brain tumors in a patient with an advanced stage of glioblastoma.

An Immunotherapy Approach to Glioblastoma

The patient is a 50-year-old man named Richard Grady who was participating in an investigational clinical trial run out of the City of Hope’s CIRM Alpha Stem Cell Clinic. A brain scan revealed a brightly lit tumor on the right side of Richard’s brain. Doctors surgically removed the tumor and treated him with radiation in an attempt to staunch further growth. But after six months, the tumors came back with a vengeance, spreading to other parts of his brain, lighting up his MRI scan like a Christmas tree.

With few treatment options and little time left, Richard was enrolled in the City of Hope trial that was testing a cell-based immunotherapy that recognizes and attacks cancer cells. It’s called CAR T-cell therapy – a term that you probably have heard in the news as a promising and cutting-edge treatment for cancer. Scientists extract immune cells, called T-cells, from a patient’s blood and reengineer them in the laboratory to recognize unique surface markers on cancer cells. These specialized CAR T-cells are then put back into the patient to attack and kill off cancer cells.

In Richard’s case, CAR-T cells were first infused into his brain through a tube in an area where a tumor was recently removed. No new tumors grew in that location of his brain, but tumors in other areas continued to grow and spread to his spinal cord. At this point, the scientists decided to place a second tube into a cavity of the brain called the ventricles, which contain a clear liquid called cerebrospinal fluid. Directly infusing into the spinal fluid allowed the cancer fighting cells to travel to different parts of the brain and spinal cord to attack the tumors.

Behnam Badie, senior author on the study and neurosurgery chief at the City of Hope, explained in a news release,

Benham Badie, City of Hope

Benham Badie, City of Hope

“By injecting the reengineered CAR-T cells directly into the tumor site and the ventricles, where the spinal fluid is made, the treatment could be delivered throughout the patient’s brain and also to the spinal cord, where this particular patient had a large metastatic tumor.”

 

Bye Bye Brain Tumors? Almost…

Three infusions of the CAR T-cell treatment shrunk Richard’s tumors noticeably, and a total of ten infusions was enough to melt away Richard’s tumors completely. Amazingly, Richard was able to reduce his medications and go back to work.

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CAR T-cell therapy reduces brain tumors when infused into the spinal fluid. (NEJM)

The effects of the immunotherapy lasted for seven-and-a-half months. Unfortunately, his glioblastoma did come back, and he is now undergoing radiation treatment. Instead of being discouraged by these results, we should be encouraged. Patients with advanced cases of glioblastoma like Richard often have only weeks left to live, and the prospect of another seven months of life with family and friends is a gift.

Following these promising results in a single patient, the City of Hope team has now treated a total of nine patients in their clinical trial. Their initial results indicate that the immunotherapy is relatively safe. Further studies will be done to determine whether this therapy will be effective at treating other types of cancers.

CIRM Alpha Clinics Advance Stem Cell Treatments

The findings in this study are particularly exciting to CIRM, not only because they offer a new treatment option for a deadly brain cancer, but also because the clinical trial testing this treatment is housed at one of our own Alpha Clinics. In 2014, CIRM funded three stem cell-focused clinics at the City of Hope, UC San Diego, and a joint clinic between UC Los Angeles and UC Irvine. These clinics are specialized to support high quality trials focused on stem cell treatments for various diseases. The CIRM team will be bringing a new Alpha Clinics concept plan to its governing Board for approval in February.

Geoff Lomax, Senior Officer of Strategic Infrastructure at CIRM who oversees the CIRM Alpha Clinics, commented on the importance of City of Hope’s glioblastoma trial,

“Treating this form of brain cancer is one of the most vexing challenges in medicine. With the support and expertise of the CIRM Alpha Stem Cell Clinic, City of Hope is harnessing the power of patients’ immune cells to treat this deadly disease.”

Neil Littman, CIRM Director of Business Development and Strategic Infrastructure added,

“This study provides important proof-of-concept that CAR-T cells can be used to target hard-to-treat solid tumors and is precisely the type of trial the CIRM Alpha Stem Cell Clinic Network is designed to support.”

For more details on this study, watch the video below from City of Hope:

Stem cell stories that caught our eye: Horse patients, Brain cancer stem cells, and a Bony Heart

Horsing around at the World Stem Cell Summit
The World Stem Cell Summit (WSCS) is coming up very shortly (December 6-9) in lovely downtown West Palm Beach, Florida. And this year it has an added attraction; horses.

For my money the WSCS is the most enjoyable of the many conferences held around the US focusing on stem cells. Most conferences have either scientists or patients and patient advocates. This brings them both together creating an event that highlights the science, the people doing it, and the people who hope to benefit from it.

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Eadweard Muybridge’s Galloping Horse
Image: Wikimedia Commons

And this year it’s not just about people, it’s also about horses. For the first time the event will feature the Equine World Stem Cell Summit. This makes sense on so many levels. Animals, large and small, have always been an important element in advancing scientific research, enabling us to test treatments and make sure they are safe before trying them out on people.

But horses are also athletes and sports has always been a powerful force in accelerating research. When you think about the “Sport of Kings” and how much money is involved in breeding and racing horses it’s not surprising that rich owners are always looking for new treatments that can help their thoroughbreds recover from injuries.

And if they help repair damaged bones and tendons in thoroughbreds, who’s to say those techniques and that research couldn’t help the rest of us.

Loss of gene allows cancer stem cells to invade the brain
A fundamental property of stem cells is their ability to self-renew and make unlimited copies of themselves. That ability is great for repairing the body but in the case of cancer stem cells, it is thought to be responsible for the uncontrolled, lethal growth of tumors.

Both stem cells and cancer stem cells rely on special cellular neighborhoods, or “niches”, to support their function. Outside of those niches, the cells don’t survive well. But cancer stem cells somehow overcome this barrier which allows them to spread and do damage to whole organs.

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Brain MRI showing glioblastoma tumor
Image: Wikimedia Commons

A study this week at The University of Texas MD Anderson Cancer Center zeroed in on the gene QK1 that, when deleted in mice, provides cancer stem cells in the brain the ability to thrive outside their niches.  They team also showed that the loss of the gene slowed a cell process called endocytosis, which normally acts to break down and recycle protein receptors on the cell surface. Those receptors are critical for the cancer stem cell’s self-renew function. So by blocking endocytosis, the gene deletion leads to an accumulation of receptors on the cell surface and in turn that boosts the cancer stem cells’ ability to divide and grow outside of its niche.

In a university press release picked up by Science Daily, team lead Jian Hu talked about exploiting this result to find new ways to defeat glioblastoma, the deadliest form of brain cancer:

“This study may lead to cancer therapeutic opportunities by targeting the mechanisms involved in maintaining cancer stem cells. Although loss of QKI allows glioma stem cells to thrive, it also renders certain vulnerabilities to the cancer cells. We hope to design new therapies to target these.”

CIRM-funded scientists uncover mystery of bone growth in the heart
Calcium helps keep our bones strong but a build-up of the mineral in our soft tissues, like the heart, is nothing but bad news for our health. The origins of this abnormal process called ectopic calcification have been a mystery to scientists because the cells responsible for forming bone and secreting calcium, called osteoblasts, are not found in the heart. So where is the calcium coming from?

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Bone-forming osteoblasts. They’re bad news when found in the heart.
Image: Amgen

This week, a CIRM-funded team at UCLA found the answer: cardiac fibroblasts. The researchers suspected that this most abundant cell in the heart was the culprit behind ectopic calcification. So, using some genetic engineering tricks, they were able to track cardiac fibroblasts with a red fluorescent tag inside mice after a heart injury.

Within a week or so after injury, the team observed that cardiac fibroblasts had clustered around the areas of calcium deposits in the heart. It turns out that those cardiac fibroblasts had taken on the properties of heart stem cells and then became bone-forming osteoblasts. To prove this finding, they took some of those cells and transplanted them into healthy mice. Sure enough, the injection sites where the cells were located began to accumulate calcium deposits.

A comparison of gene activity in these abnormal cells versus healthy cells identified a protein called EPPN1 whose levels were really elevated when these calcium deposits occurred. Blocking EPPN1 put a stop to the calcification in the heart. In a university press release, lead author Arjun Deb explained that this detective work may lead to long sought after therapies:

Everyone recognizes that calcification of the heart and blood vessels and kidneys is abnormal, but we haven’t had a single drug that can slow down or reverse calcification; our study points to some therapeutic targets.

Achilles’ Heel of Brain Cancer Identified in Tumor Stem Cells

Few words strike me with more dread than glioblastoma, the name for a very aggressive, incurable cancer of the brain. Although surgery and chemotherapy can help hold off or reverse a glioblastoma’s growth for a while, almost inevitably the tumor comes back along with a terrible prognosis: an average survival time of 12 to 15 months after diagnosis with a less than 5% survival rate beyond five years.

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MRI scans of glioblastoma in the brain of a 15 year-old boy.
Image: Wikipedia

Brain tumor stem cells (BTSCs) are thought to be the culprits behind the cancer’s reoccurrence because of their stem cell-like ability for limitless self-renewal. So the idea is that even a tiny number of BTSCs left behind after treatment will likely to lead to a tumor regrowth and treatment relapse. If researchers can better understand what makes the BTSCs tick, they could find ways to eliminate them and cure this dreadful disease.

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Brain tumor stem cells (BTSCs).
Image: Takrima Haque / Arezu Jahani-Asl Laboratory

This week researchers largely from The Ottawa Hospital Research Institute report on the identification of a key piece of BTSCs’ molecular machinery that provides a promising target for novel glioblastoma treatments. The study, published in Nature Neuroscience, focuses on the epidermal growth factor (EGF) cell signaling pathway. In normal cells, the EGF protein binds to the EGF receptor (EGFR) on a cell’s surface which triggers a cascade of protein interactions inside the cell that stimulate cell growth among other things.

EGFRvIII: a cancer stem cell gas pedal stuck to the floorboard
Eventually a given EGF signaling event subsides. But many BTSCs found in glioblastoma tissue samples have a mutant form of EGFR, called EGFRvIII, that permanently switches this signaling pathway into the “on position” even in the absence of EGF. It’s like the gas pedal of a car that gets stuck to the floorboard, causing the car to dangerously accelerate even though no one is pressing on the accelerator.

Previous studies had shown this always-on EGFRvIII growth signal causes abnormally high activation of a messenger protein, STAT3, which in turn hyper stimulates a network of genes that leads to cancerous growth of the tumor stem cells. But it wasn’t clear exactly how this protein carries out the uncontrolled cell division. Through a detailed genetic analysis of BTSCs from several glioblastoma patient samples, the team zeroed in on the oncostatin M receptor (OSMR) as a critical player. This analysis revealed that STAT3 was a natural activator of the OSMR gene and that high levels of both proteins in patient samples correlated to a poorer prognosis.

No OSMR = no tumors
To investigate further, human BTSCs genetically engineered to lack OSMR were injected under the skin of mice and showed an 80% reduction in tumor formation. Injection of similar cells directly into the brains of mice found no tumor formation when OSMR was absent. In an interview posted by Genetic Engineering News, senior author Michael Rudnicki recalled his team’s reaction to this finding:

“Being able to stop tumor formation entirely was a dramatic and stunning result. It means that this protein is a key piece of the puzzle, and could be a possible target for future treatments.”

Three proteins form a vicious cycle toward cancerous growth
Additional experiments testing the interactions between EGFRvIII, STAT3 and OSMR point out where those future treatments should act. Like the screeching audio feedback you hear when a microphone is held too close to a speaker, the team showed these three proteins create a self amplifying signal. In the tumor stem cells, EGFRvIII comes in direct physical contact with OSMR and together these two proteins act as co-receptors to activate STAT3 which, in turn, stimulates the production of OSMR which, in turn, stimulates even more STAT3 production. And so on and so on.

Co-senior author, Azad Bonni, explained how they intend to break up this vicious cycle while also acknowledging these are very early days for developing a treatment:

“The next step is to find small molecules or antibodies that can shut down the protein OSMR or stop it from interacting with EGFR. But any human treatment targeting this protein is years away.”

Watch this video to hear from the study’s first author, Arezu Jahani-Asl, now an assistant professor at McGill university:

 

Funding a clinical trial for deadly cancer is a no brainer

The beast of cancers
For a disease that is supposedly quite rare, glioblastoma seems to be awfully common. I have lost two friends to the deadly brain cancer in the last few years. Talking to colleagues and friends here at CIRM, it’s hard to find anyone who doesn’t know someone who has died of it.

Immunocellular

Imagery of glioblastoma, a deadly brain cancer,  from ImmunoCellular’s website

So when we got an application to fund a Phase 3 clinical trial to target the cancer stem cells that help fuel glioblastoma, it was really a no brainer to say yes. Of course it helped that the scientific reviewers – our Grants Working Group or GWG – who looked at the application voted unanimously to approve it. For them, it was great science for an important cause.

Today our Board agreed with the GWG and voted to award $19.9 million to LA-based ImmunoCellular Therapeutics to carry out a clinical trial that targets glioblastoma cancer stem cells. They’re hoping to begin the trial very soon, recruiting around 400 newly diagnosed patients at some 120 clinical sites around the US, Canada and Europe.

There’s a real urgency to this work. More than 50 percent of those diagnosed with glioblastoma die within 15 months, and more than 90 percent within three years. There are no cures and no effective long-term treatments.

As our President and CEO, Dr. Randy Mills, said in a news release:

 “This kind of deadly disease is precisely why we created CIRM 2.0, our new approval process to accelerate the development of therapies for patients with unmet medical needs. People battling glioblastoma cannot afford to wait years for us to agree to fund a treatment when their survival can often be measured in just months. We wanted a process that was more responsive to the needs of patients, and that could help companies like ImmunoCellular get their potentially life-saving therapies into clinical trials as quickly as possible.”

The science
The proposed treatment involves some rather cool science. Glioblastoma stem cells can evade standard treatments like chemotherapy and cause the recurrence and growth of the tumors. The ImmunoCellular therapy addresses this issue and targets six cell surface proteins that are found on glioblastoma cancer stem cells.

The researchers take immune cells from the patient’s own immune system and expose them to fragments of these cancer stem cell surface proteins in the lab. By re-engineering the immune cells in this way they are then able to recognize the cancer stem cells.

My colleague Todd Dubnicoff likened it to letting a bloodhound sniff a piece of clothing from a burglar so it’s able to recognize the scent and hunt the burglar down.  When the newly trained immune system cells are returned to the patient’s body, they can now help “sniff out” and hopefully kill the cancer stem cells responsible for the tumor’s recurrence and growth.

Like a bloodhound picking up the scent of a burglar, ImmunoCellular's therapy helps the immune system track down brain cancer stem cells (source: wikimedia commons)

Like a bloodhound picking up the scent of a burglar, ImmunoCellular’s therapy helps the immune system track down brain cancer stem cells (source: Wikimedia Commons)

Results from both ImmunoCellular’s Phase 1 and 2 trials using this approach were encouraging, showing that patients given the therapy lived longer than those who got standard treatment and experienced only minimal side effects.

Turning the corner against glioblastoma
There’s a moment immediately after the Board votes “yes” to fund a project like this. It’s almost like a buzz, where you feel that you have just witnessed something momentous, a moment where you may have turned the corner against a deadly disease.

We have a saying at the stem cell agency: “Come to work every day as if lives depend on it, because lives depend on it.” On days like this, you feel that we’ve done something that could ultimately help save some of those lives.

The Man Behind the Curtain: Protein Helps Keep Cancer Cells Alive and Kicking

Being diagnosed with brain cancer comes with a sobering sentence: even with the most aggressive treatments, life expectancy for the most common form of brain cancer—called glioblastoma—is less than two years.

One of the key culprits, many scientists now believe, are cancer stem cells. Cancer stem cells are a subset of cancer cells that have three very unique properties: they can self-renew, they can propagate (or multiply) the cancer, and they can transform into the many types of cells that are found in a tumor.

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Cancer stem cells are a relatively new concept, but they have generated a lot of excitement among cancer researchers because they could lead to the design of more effective therapies. And while whether or not they even existed has long been a source of debate among experts, a series of recent research findings have bolstered the notion not only that they exist, but also that they play a significant role in the recurrence of some forms of cancer—including glioblastoma.

Researchers have been identifying, step by step, the many proteins and chemical pathways that form the path from cancer stem cell to tumor. Previous research had found the CDK class of proteins to be present in large quantities in mature cancer cells in patients suffering from glioblastoma. But they suspected something else was at play, helping to keep the CDK proteins switched on in mature cancer cells.

So scientists at McGill University in Canada, led by neurologist Dr. Anita Bellail, dug deeper. In their report, published this week in the journal Nature Communications, the team has pinpointed a new class of proteins at play behind the scenes called SUMO.

Specifically, Bellail and her team observed that the SUMO1 protein in particular modifies a CDK protein called CDK6 in a process the team has dubbed ‘sumylation.’ As Bellail explained in this week’s news release:

“CDK6 sumylation inhibits its degradation and thus stabilizes the CDK6 protein in the cancer.”

In other words, the CDK6 protein does not by itself maintain a presence in the cancer cells. Instead, it requires a little help from SUMO1. As Bellail continued:

“We found that CDK6 sumylation is required for the renewal and growth of the cancer stem cells in glioblastoma.”

It stands to reason, therefore, that shutting off SUMO1 could do the reverse—thus destabilizing CDK6 and, potentially, block the progression of the cancer.

And in further experiments by Bellail and her team, they found exactly that.

These results hold significant promise for finding new ways to treat glioblastoma because now the team has a target: SUMO1. In fact, the research team is now screening for drugs that can target SUMO1 and block it, thus reducing CDK6 levels and, as a result, cancer cells—and one day offering a more optimistic outcome for those diagnosed with glioblastoma.

Want to learn more about cancer stem cells? Check out our 2009 “Spotlight on Cancer Stem Cells” video starring Dr. Michael Clarke, associate director of the Stanford Institute for Stem Cell and Regenerative Medicine.