Protein that turns normal cells into cancer stem cells offers target to fight colon cancer

colon-cancer

Colon cancer: Photo courtesy WebMD

Colon cancer is a global killer. Each year more than one million people worldwide are diagnosed with it; more than half a million die from it. If diagnosed early enough the standard treatment involves surgery, chemotherapy, radiation or targeted drug therapy to destroy the tumors. In many cases this may work. But in some cases, while this approach helps put people in remission, eventually the cancer returns, spreads throughout the body, and ultimately proves fatal.

Now researchers may have identified a protein that causes normal cells to become cancerous, and turn into cancer stem cells (CSCs). This discovery could help provide a new target for anti-cancer therapies.

Cancer stem cells are devilishly tricky. While most cancer cells are killed by chemotherapy or other therapies, cancer stem cells are able to lie dormant and hide, then emerge later to grow and spread, causing the person to relapse and the cancer to return.

In a study published in Nature Research’s Scientific Reports, researchers at SU Health New Orleans School of Medicine and Stanley S. Scott Cancer Center identified a protein, called SATB2, that appears to act as an “on/off” switch for specific genes inside a cancer cell.

In normal, healthy colorectal tissue SATB2 is not active, but in colorectal cancer it is highly active, found in around 85 percent of tumors. So, working with mice, the researchers inserted extra copies of the SATB2 gene, which produced more SATB2 protein in normal colorectal tissue. They found that this produced profound changes in the cell, leading to uncontrolled cell growth. In effect it turned a normal cell into a cancer stem cell.

As the researchers state in their paper:

“These data suggest that SATB2 can transform normal colon epithelial cells to CSCs/progenitor-like cells which play significant roles in cancer initiation, promotion and metastasis.”

When the researchers took colorectal cancer cells and inhibited SATB2 they found that this not only suppressed the growth of the cancer and it’s ability to spread, it also prevented those cancer cells from becoming cancer stem cells.

In a news release about the study Dr. Rakesh Srivastava,  the senior author on the paper, said the findings are important:

“Since the SATB2 protein is highly expressed in the colorectal cell lines and tissues, it can be an attractive target for therapy, diagnosis and prognosis.”

Because SATB2 is found in other cancers too, such as breast cancer, these findings may hold significance for more than just colorectal cancer.

The next step is to repeat the study in mice that have been genetically modified to better reflect the way colon cancer shows up in people. The team hope this will not only confirm their findings, but also give them a deeper understanding of the role that SATB2 plays in cancer formation and spread.

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UCLA launches CIRM-funded clinical trial using engineered blood stem cells to treat skin cancer

It’s not uncommon for biomedical institutes as well as their funding partners to announce through press releases that a clinical trial they’re running has gotten off the ground and has started to enroll patients. For an outsider looking in, it may seem like they’re jumping the gun a bit. No patients have received the therapy. No cures have been declared. So why all the hubbub at the start?

The reality is this: the launch of a clinical trial isn’t a beginning. It represents many years of effort by many researchers and a lot of funding to take an idea and develop it into a tangible product that has been given clearance to be tested in people to potentially save their lives. That’s why this important milestone deserves to be recognized. So, we were excited to get the word out, in the form of a press release , that UCLA had announced this morning the launch of a CIRM-funded clinical trial testing a therapy for hard-to-treat cancers.

The UCLA clinical trial genetically alters a patient’s hematopoietic stem cells give rise to T cells that are efficient cancer killers.

It’s estimated that metastasis, or the spread of cancer to other parts of the body, is responsible for 90% of cancer deaths. Though radiation and chemotherapy treatments can stop a tumor in its tracks, a small population of cancer stem cells in the tumor lie dormant and can evade those anti-cancer approaches. Because of their unlimited potential to divide, the cancer stem cells regrow the tumor leading to its inevitable return and spread. Oncologists clearly need new approaches to help patients with this unmet medical need.

That’s where today’s clinical trial launch comes into the picture. Dr. Antonio Ribas, a member of the UCLA Broad Stem Cell Research Center, and his team have genetically engineered cancer-killing white blood cells called T cells and blood-forming stem cells collected from patients to produce a protein that, like a key in a lock, recognizes a protein found almost exclusively on the surface of many types of cancer. When the T cells are transfused back into the patient, they can more efficiently track down and eradicate hard-to-treat skin cancer stem cells. At the same, the transfused blood stem cells – which specialize into all the various immune system cells – provide a long-term supply of T cells for continued protection against reoccurrence of the tumor.

“Few options exist for the treatment of patients whose cancers have metastasized due to resistance to current therapies,” Ribas said in the UCLA press release. “This clinical trial will allow us to try a new approach that engineers the body’s immune system to fight metastasized tumors similar to how it fights germs and viruses.”

 

And as Dr. Maria Millan, CIRM’s President & CEO (interim), described in our accompanying press release, CIRM will be an ever-present partner to help Ribas’ team get the clinical trial smoothly out of the starting gate and provide the support needed to carry the therapy to its completion:

“This trial is the first step in developing a therapy that could alleviate the complications resulting from cancer metastases as well as potentially improving outcomes in cancer patients where there are currently no effective treatment options. We are confident that CIRM’s funding and partnership, in combination with the expertise provided by our Alpha Stem Cell Clinic network, will give provide critical support for the successful conduct of this important clinical trial.”

 

To learn more about this clinical trial, visit its page at clinicaltrials.gov. If you think you might be eligible to enroll, please contact Clinical Research Coordinator Justin Tran by email at justintran@mednet.ucla.edu or by phone at 310-206-2090.

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.”

 

Confusing cancer to kill it

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Thomas Kipps, MD, PhD: Photo courtesy UC San Diego

Confusion is not a state of mind that we usually seek out. Being bewildered is bad enough when it happens naturally, so why would anyone actively pursue it? But now some researchers are doing just that, using confusion to not just block a deadly blood cancer, but to kill it.

Today the CIRM Board approved an investment of $18.29 million to Dr. Thomas Kipps and his team at UC San Diego to use a one-two combination approach that we hope will kill Chronic Lymphocytic Leukemia (CLL).

This approach combines two therapies, cirmtuzumab (a monoclonal antibody developed with CIRM funding, hence the name) and Ibrutinib, a drug that has already been approved by the US Food and Drug Administration (FDA) for patients with CLL.

As Dr. Maria Millan, our interim President and CEO, said in a news release, the need for a new treatment is great.

“Every year around 20,000 Americans are diagnosed with CLL. For those who have run out of treatment options, the only alternative is a bone marrow transplant. Since CLL afflicts individuals in their 70’s who often have additional medical problems, bone marrow transplantation carries a higher risk of life threatening complications. The combination approach of  cirmtuzumab and Ibrutinib seeks to offer a less invasive and more effective alternative for these patients.”

Ibrutinib blocks signaling pathways that leukemia cells need to survive. Disrupting these pathways confuses the leukemia cell, leading to its death. But even with this approach there are cancer stem cells that are able to evade Ibrutinib. These lie dormant during the therapy but come to life later, creating more leukemia cells and causing the cancer to spread and the patient to relapse. That’s where cirmtuzumab comes in. It works by blocking a protein on the surface of the cancer stem cells that the cancer needs to spread.

It’s hoped this one-two punch combination will kill all the cancer cells, increasing the number of patients who go into complete remission and improve their long-term cancer control.

In an interview with OncLive, a website focused on cancer professionals, Tom Kipps said Ibrutinib has another advantage for patients:

“The patients are responding well to treatment. It doesn’t seem like you have to worry about stopping therapy, because you’re not accumulating a lot of toxicity as you would with chemotherapy. If you administered chemotherapy on and on for months and months and years and years, chances are the patient wouldn’t tolerate that very well.”

The CIRM Board also approved $5 million for Angiocrine Bioscience Inc. to carry out a Phase 1 clinical trial testing a new way of using cord blood to help people battling deadly blood disorders.

The standard approach for this kind of problem is a bone marrow transplant from a matched donor, usually a family member. But many patients don’t have a potential donor and so they often have to rely on a cord blood transplant as an alternative, to help rebuild and repair their blood and immune systems. However, too often a single cord blood donation does not have enough cells to treat an adult patient.

Angiocrine has developed a product that could help get around that problem. AB-110 is made up of cord blood-derived hematopoietic stem cells (these give rise to all the other types of blood cell) and genetically engineered endothelial cells – the kind of cell that lines the insides of blood vessels.

This combination enables the researchers to take cord blood cells and greatly expand them in number. Expanding the number of cells could also expand the number of patients who could get these potentially life-saving cord blood transplants.

These two new projects now bring the number of clinical trials funded by CIRM to 35. You can read about the other 33 here.

 

 

 

New research suggests taking a daily dose of vitamin C could prevent leukemia

Did you take your vitamins today? It’s not always easy to remember with such busy lives, but after you read this blog, you’ll be sure to make vitamins part of your daily routine if you haven’t already!

Two recent studies, published in the journals Nature and Cell, reported that vitamin C has a direct impact on the function of blood forming, or hematopoietic stem cells, and can be used to protect mice from getting a blood cancer called leukemia.

Science reporter Bradley Fikes compared the findings of the two studies yesterday in the San Diego Union Tribune. According to Fikes, the Nature study, which was conducted by scientists at UT Southwestern, “found that human and mouse hematopoietic stem cells absorb unusually large amounts of vitamin C. When the cells were depleted of vitamin C, they were more likely to turn into leukemia cells.”

As for the Cell study, scientists from NYU Langone Health “found that high doses of vitamin C can cause leukemic cells to die, potentially making it a useful and safe chemotherapy agent.” For more details on this particular study, see our blog from last week and the video below.

Dr. Benjamin Neel, director of NYU Langone’s Perlmutter Cancer Center, discusses how vitamin C may “tell” faulty stem cells in the bone marrow to mature and die normally, instead of multiplying to cause blood cancers.

Vitamin C levels are crucial for preventing leukemia

The common factor between the two studies is a gene called Tet2, which is turned on in blood stem cells and protects them from over-proliferating and acquiring genetic mutations that transform them into leukemia cells. If one copy of the Tet2 gene is genetically mutated, treating blood stem cells with vitamin C can make up for this partial loss in Tet2 function. However, if both copies of Tet2 are mutated, its protective functions are completely lost and blood stem cells can turn cancerous.

Fikes reached out to Sean Morrison, senior author on the Nature study, for an explanation about the relationship between vitamin C and Tet2, and how it can be leveraged to prevent or treat leukemia:

Sean Morrison

“The Cell study showed that high doses of vitamin C can compensate for Tet2 mutations, restoring normal function, Morrison said. Usually, transformation of normal cells into leukemic cells is irreversible, but the study demonstrated that’s not true when the leukemia is driven by Tet2 mutations.”

“The Nature study demonstrated that vitamin C is a limiting factor in the proper function of Tet2, Morrison said. People have two copies of the gene, one from each parent. When one of the genes is disabled, it’s important to take the full recommended dose of vitamin C so the remaining gene can exert its full tumor-suppressing effect.”

Before you place your bulk order of vitamin C on amazon, you should be aware that Morrison and his colleagues found that giving mice super doses of the supplement failed to further reduce their risk of getting leukemia. Thus, it seems that having the right levels of vitamin C in blood stem cells and healthy copies of the Tet2 gene are vital for preventing leukemia.

Vitamin C, a panacea for cancer?

These two studies raise important questions. Do vitamin C levels play a role in the development of other cancer cells and could this supplement be used as a treatment for other types of cancers?

Since the 1970’s, scientists (including the famous American scientist Linus Pauling) and doctors have pursued vitamin C as a potential cancer treatment. Early stage research revealed that vitamin C plays a role in slowing the growth of various types of cancer cells including prostate, colon and brain cancer cells. More recently, some of this research has progressed to clinical trials that are testing high-doses of vitamin C either by itself or in combination with chemotherapy drugs in cancer patients. Some of these trials have reported an improved quality of life and increased average survival time in patients, but more research and trials are necessary to determine whether vitamin C is a truly effective anti-cancer therapy.

Now that Morrison and his team have a better understanding of how vitamin C levels affect cancer risk, they plan to address some of these outstanding questions in future studies.

“Our data also suggest that probably not all cancers are increased by vitamin C depletion. We particularly would predict that certain leukemias would be increased in the absence of vitamin C. We’re collaborating with the Centers for Disease Control right now to look more carefully at the epidemiological data that have been collected over decades, to understand more precisely which cancers are at increased risk in people that have lower levels of vitamin C.”

CIRM weekly stem cell roundup: stomach bacteria & cancer; vitamin C may block leukemia; stem cells bring down a 6’2″ 246lb football player

gastric

This is what your stomach glands looks like from the inside:  Credit: MPI for Infection Biology”

Stomach bacteria crank up stem cell renewal, may be link to gastric cancer (Todd Dubnicoff)

The Centers for Disease Control and Prevention estimate that two-thirds of the world’s population is infected with H. pylori, a type of bacteria that thrives in the harsh acidic conditions of the stomach. Data accumulated over the past few decades shows strong evidence that H. pylori infection increases the risk of stomach cancers. The underlying mechanisms of this link have remained unclear. But research published this week in Nature suggests that the bacteria cause stem cells located in the stomach lining to divide more frequently leading to an increased potential for cancerous growth.

Tumors need to make an initial foothold in a tissue in order to grow and spread. But the cells of our stomach lining are replaced every four days. So, how would H. pylori bacterial infection have time to induce a cancer? The research team – a collaboration between scientists at the Max Planck Institute in Berlin and Stanford University – asked that question and found that the bacteria are also able to penetrate down into the stomach glands and infect stem cells whose job it is to continually replenish the stomach lining.

Further analysis in mice revealed that two groups of stem cells exist in the stomach glands – one slowly dividing and one rapidly dividing population. Both stem cell populations respond similarly to an important signaling protein, called Wnt, that sustains stem cell renewal. But the team also discovered a second key stem cell signaling protein called R-spondin that is released by connective tissue underneath the stomach glands. H. pylori infection of these cells causes an increase in R-spondin which shuts down the slowly dividing stem cell population but cranks up the cell division of the rapidly dividing stem cells. First author, Dr. Michal Sigal, summed up in a press release how these results may point to stem cells as the link between bacterial infection and increased risk of stomach cancer:

“Since H. pylori causes life-long infections, the constant increase in stem cell divisions may be enough to explain the increased risk of carcinogenesis observed.”

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Vitamin C may have anti-blood cancer properties

Vitamin C is known to have a number of health benefits, from preventing scurvy to limiting the buildup of fatty plaque in your arteries. Now a new study says we might soon be able to add another benefit: it may be able to block the progression of leukemia and other blood cancers.

Researchers at the NYU School of Medicine focused their work on an enzyme called TET2. This is found in hematopoietic stem cells (HSCs), the kind of stem cell typically found in bone marrow. The absence of TET2 is known to keep these HSCs in a pre-leukemic state; in effect priming the body to develop leukemia. The researchers showed that high doses of vitamin C can prevent, or even reverse that, by increasing the activity level of TET2.

In the study, in the journal Cell, they showed how they developed mice that could have their levels of TET2 increased or decreased. They then transplanted bone marrow with low levels of TET2 from those mice into healthy, normal mice. The healthy mice started to develop leukemia-like symptoms. However, when the researchers used high doses of vitamin C to restore the activity levels of TET2, they were able to halt the progression of the leukemia.

Now this doesn’t mean you should run out and get as much vitamin C as you can to help protect you against leukemia. In an article in The Scientist, Benjamin Neel, senior author of the study, says while vitamin C does have health benefits,  consuming large doses won’t do you much good:

“They’re unlikely to be a general anti-cancer therapy, and they really should be understood based on the molecular understanding of the many actions vitamin C has in cells.”

However, Neel says these findings do give scientists a new tool to help them target cells before they become leukemic.

Jordan reed

Bad toe forces Jordan Reed to take a knee: Photo courtesy FanRag Sports

Toeing the line: how unapproved stem cell treatment made matters worse for an NFL player  

American football players are tough. They have to be to withstand pounding tackles by 300lb men wearing pads and a helmet. But it wasn’t a crunching hit that took Washington Redskins player Jordan Reed out of the game; all it took to put the 6’2” 246 lb player on the PUP (Physically Unable to Perform) list was a little stem cell injection.

Reed has had a lingering injury problem with the big toe on his left foot. So, during the off-season, he thought he would take care of the issue, and got a stem cell injection in the toe. It didn’t quite work the way he hoped.

In an interview with the Richmond Times Dispatch he said:

“That kind of flared it up a bit on me. Now I’m just letting it calm down before I get out there. I’ve just gotta take my time, let it heal and strengthen up, then get back out there.”

It’s not clear what kind of stem cells Reed got, if they were his own or from a donor. What is clear is that he is just the latest in a long line of athletes who have turned to stem cells to help repair or speed up recovery from an injury. These are treatments that have not been approved by the Food and Drug Administration (FDA) and that have not been tested in a clinical trial to make sure they are both safe and effective.

In Reed’s case the problem seems to be a relatively minor one; his toe is expected to heal and he should be back in action before too long.

Stem cell researcher and avid blogger Dr. Paul Knoepfler wrote he is lucky, others who take a similar approach may not be:

“Fortunately, it sounds like Reed will be fine, but some people have much worse reactions to unproven stem cells than a sore toe, including blindness and tumors. Be careful out there!”

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.

Treatments, cures and clinical trials: an in-person update on CIRM’s progress

Patients and Patient Advocates are at the heart of everything we do at CIRM. That’s why we are holding three free public events in the next few months focused on updating you on the stem cell research we are funding, and our plans for the future.

Right now we have 33 projects that we have funded in clinical trials. Those range from heart disease and stroke, to cancer, diabetes, ALS (Lou Gehrig’s disease), two different forms of vision loss, spinal cord injury and HIV/AIDS. We have also helped cure dozens of children battling deadly immune disorders. But as far as we are concerned we are only just getting started.

Over the course of the next few years, we have a goal of adding dozens more clinical trials to that list, and creating a pipeline of promising therapies for a wide range of diseases and disorders.

That’s why we are holding these free public events – something we try and do every year. We want to let you know what we are doing, what we are funding, how that research is progressing, and to get your thoughts on how we can improve, what else we can do to help meet the needs of the Patient Advocate community. Your voice is important in helping shape everything we do.

The first event is at the Gladstone Institutes in San Francisco on Wednesday, September 6th from noon till 1pm. The doors open at 11am for registration and a light lunch.

Gladstone Institutes

Here’s a link to an Eventbrite page that has all the information about the event, including how you can RSVP to let us know you are coming.

We are fortunate to be joined by two great scientists, and speakers – as well as being CIRM grantees-  from the Gladstone Institutes, Dr. Deepak Srivastava and Dr. Steve Finkbeiner.

Dr. Srivastava is working on regenerating heart muscle after it has been damaged. This research could not only help people recover from a heart attack, but the same principles might also enable us to regenerate other organs damaged by disease. Dr. Finkbeiner is a pioneer in diseases of the brain and has done ground breaking work in both Alzheimer’s and Huntington’s disease.

We have two other free public events coming up in October. The first is at UC Davis in Sacramento on October 10th (noon till 1pm) and the second at Cedars-Sinai in Los Angeles on October 30th (noon till 1pm). We will have more details on these events in the coming weeks.

We look forward to seeing you at one of these events and please feel free to share this information with anyone you think might be interested in attending.

UC Irvine scientists engineer stem cells to “feel” cancer and destroy it

By blocking cell division, chemotherapy drugs take advantage of the fact that cancer cells multiply rapidly in the body. Though this treatment can extend and even save the lives of cancer patients, it’s somewhat like destroying an ant hill with an atomic bomb: there’s a lot of collateral damage. The treatment is infused through the blood so healthy cells that also divide frequently – like those in hair follicles, the intestines and bone marrow – succumb to the chemotherapy. To add insult to injury, cancers often become resistant to these drugs and metastasize, or invade, other parts of the body. Sadly, this spreading of a cancer is responsible for 90% of cancer deaths.

uci-stem-cell-therapy-attacks-cancer-by-targeting-unique-tissue-stiffness

UCI doctoral students Shirley Zhang, left, and Linan Liu are co-leading authors of the study. Photo: UC Irvine

Developing more specific, effective anti-cancer therapies is the focus of many research institutes and companies. While some new strategies target cell surface proteins that are unique to cancer cells, a UC Irvine (UCI) team has devised a stem cell-based technique that can seek out and destroy breast cancer cells that have metastasized in the lungs of mice by sensing the stiffness of the surrounding tissue. The CIRM-funded study was published this week in Science Translational Medicine.

While cells make up the tissues and organs of our bodies, they also secrete proteins and molecules that form a scaffold between cells called the extracellular matrix. This cell scaffolding is not just structural, it also plays a key role in regulating cell growth and other functions. And previous studies have shown that at sites of tumors, accumulation of collagen and other proteins in the matrix increases tissue stiffness and promotes metastasis.

Based on this knowledge, the UCI team aimed to create a cell system that would release chemotherapy drugs in response to increased stiffness. It turns out that mesenchymal stem cells – which give rise to bone, muscle, cartilage and fat – not only migrate to tumors in the body but also activate particular genes in response to the stiffness of their local cellular environment.  The researchers engineered mesenchymal stem cells to carry a gene that codes for a protein involved in the activation of a chemotherapy drug which is given by mouth. They also designed the gene to turn on only when it encounters stiff, cancerous tissue. They called the method a mechanoresponsive cell system (MRCS).

To test the MRCS, mice were infused with human breast cancer cells, which metastasized or spread to the lung. The MRCS-engineered mesenchymal stem cells were infused through the blood and homed to the lungs where they activated the chemotherapy drug which caused localized killing of the tumor cells with minimal damage to lung tissue. When the MRSC stem cells were given to mice without tumors, no increase in tissue damage was seen, proving that the MRSC-induced chemotherapy drug is only activated in the presence of cancerous tissue and has few side effects.

In a press release, team leader Weian Zhao, explained that these promising results could have wide application:

Weian-Zhao2-757x1024

Weian Zhao
Photo: UC Irvine

“This published work is focused on breast cancer metastases in the lungs. However, the technology will be applicable to other metastases as well, because many solid tumors have the hallmark of being stiffer than normal tissue. This is why our system is innovative and powerful, as we don’t have to spend the time to identify and develop a new genetic or protein marker for every kind of cancer.”

 

The team envisions even more applications. The MRCS could be engineered to carry genes that would enable detection with imaging technologies like PET scans. In this scenario, the MRCS could act as a highly sensitive detection system for finding areas of very early metastases when current techniques would miss them. They could also design the MRCS to activate genes that code for proteins that can break down and soften the stiff cancerous tissues which may inhibit the ability for a tumor to spread.

Stories that caught our eye: Spinal cord injury trial milestone, iPS for early cancer diagnosis, and storing videos in DNA

Spinal cord injury clinical trial hits another milestone (Kevin McCormack)
We began the week with good news about our CIRM-funded clinical trial with Asterias for spinal cord injury, and so it’s nice to end the week with more good news from that same trial. On Wednesday, Asterias announced it had completed enrolling and dosing patients in their AIS-B 10 million cell group.

asterias

People with AIS-B spinal cord injuries have some level of sensation and feeling but very little, if any, movement below the site of injury site. So for example, spinal cord injuries at the neck, would lead to very limited movement in their arms and hands. As a result, they face a challenging life and may be dependent on help in performing most daily functions, from getting out of bed to eating.astopc1

In another branch of the Asterias trial, people with even more serious AIS-A injuries – in which no feeling or movement remains below the site of spinal cord injury – experienced improvements after being treated with Asterias’ AST-OPC1 stem cell therapy. In some cases the improvements were quite dramatic. We blogged about those here.

In a news release Dr. Ed Wirth, Asterias’ Chief Medical Officer, said they hope that the five people treated in the AIS-B portion of the trial will experience similar improvements as the AIS-A group.

“Completing enrollment and dosing of the first cohort of AIS-B patients marks another important milestone for our AST-OPC1 program. We have already reported meaningful improvements in arm, hand and finger function for AIS-A patients dosed with 10 million AST-OPC1 cells and we are looking forward to reporting initial efficacy and safety data for this cohort early in 2018.”

Asterias is already treating some AIS-A patients with 20 million cells and hopes to start enrolling AIS-B patients for the 20 million cell therapy later this summer.

Earlier diagnosis of pancreatic cancer using induced pluripotent stem cells Reprogramming adult cells to an embryonic stem cell-like state is as common in research laboratories as hammers and nails are on a construction site. But a research article in this week’s edition of Science Translational Medicine used this induced pluripotent stem cell (iPSC) toolbox in a way I had never read about before. And the results of the study may lead to earlier detection of pancreatic cancer, the fourth leading cause of cancer death in the U.S.

Zaret STM pancreatic cancer tissue July 17

A pancreatic ductal adenocarcinoma
Credit: The lab of Ken Zaret, Perelman School of Medicine, University of Pennsylvania

We’ve summarized countless iPSCs studies over the years. For example, skin or blood samples from people with Parkinson’s disease can be converted to iPSCs and then specialized into brain cells to provide a means to examine the disease in a lab dish. The starting material – the skin or blood sample – typically has no connection to the disease so for all intents and purposes, it’s a healthy cell. It’s only after specializing it into a nerve cell that the disease reveals itself.

But the current study by researchers at the University of Pennsylvania used late stage pancreatic cancer cells as their iPSC cell source. One of the reasons pancreatic cancer is thought to be so deadly is because it’s usually diagnosed very late when standard treatments are less effective. So, this team aimed to reprogram the cancer cells back into an earlier stage of the cancer to hopefully find proteins or molecules that could act as early warning signals, or biomarkers, of pancreatic cancer.

Their “early-stage-cancer-in-a-dish” model strategy was a success. The team identified a protein called thrombospodin-2 (THBS2) as a new candidate biomarker. As team lead, Dr. Ken Zaret, described in a press release, measuring blood levels of THBS2 along with a late-stage cancer biomarker called CA19-9 beat out current detection tests:

“Positive results for THBS2 or CA19-9 concentrations in the blood consistently and correctly identified all stages of the cancer. Notably, THBS2 concentrations combined with CA19-9 identified early stages better than any other known method.”

DNA: the ultimate film archive device?
This last story for the week isn’t directly related to stem cells but is too cool to ignore. For the first time ever, researchers at Harvard report in Nature that they have converted a video into a DNA sequence which was then inserted into bacteria. As Gina Kolata states in her New York Times article about the research, the study represents the ultimate data archive system which can “be retrieved at will and multiplied indefinitely as the host [bacteria] divides and grows.”

A video file is nothing but a collection of “1s” and “0s” of binary code which describe the makeup of each pixel in each frame of a movie. The researchers used the genetic code within DNA to describe each pixel in a short clip of one of the world’s first motion pictures: a galloping horse captured by Eadward Muybridge in 1878.

Horse_1080.gif

The resulting DNA sequence was then inserted into the chromosome of E.Coli., a common bacteria that lives in your intestines, using the CRISPR gene editing method. The video code was still retrievable after the bacteria was allowed to multiply.

The Harvard team envisions applications well beyond a mere biological hard drive. Dr. Seth Shipman, an author of the study, told Paul Rincon of BBC news that he thinks this cell system could be placed in various parts of the body to analyze cell function and “encode information about what’s going on in the cell and what’s going on in the cell environment by writing that information into their own genome”.

Perhaps then it could be used to monitor the real-time activity of stem cell therapies inside the body. For now, I’ll wait to hear about that in some upcoming science fiction film.