Helping patient’s fight back against deadliest form of skin cancer

Caladrius Biosciences has been funded by CIRM to conduct a Phase 3 clinical trial to treat the most severe form of skin cancer: metastatic melanoma. Metastatic melanoma is a disease with no effective treatment, only around 15 percent of people with it survive five years, and every year it claims an estimated 10,000 lives in the U.S.

The CIRM/Caladrius Clinical Advisory Panel meets to chart future of clinical trial

The CIRM/Caladrius Clinical Advisory Panel meets to chart future of clinical trial

The Caladrius team has developed an innovative cancer treatment that is designed to target the cells responsible for tumor growth and spread. These are called cancer stem cells or tumor-initiating cells. Cancer stem cells can spread in the body because they have the ability to evade the body’s immune defense and survive standard anti-cancer treatments such as chemotherapy. The aim of the Caladrius treatment is to train the body’s immune system to recognize the cancer stem cells and attack them.

Attacking the cancer

The treatment process involves taking a sample of a patient’s own tumor and, in a laboratory, isolating specific cells responsible for tumor growth . Cells from the patient’s blood, called “peripheral blood monocytes,” are also collected. The mononucleocytes are responsible for helping the body’s immune system fight disease. The tumor and blood cells (after maturation into dendritic cells) are then combined and incubated so that the patient’s immune cells become trained to recognize the cancer cells.

After the incubation period, the patient’s immune cells are injected back into their body where they generate an immune response to the cancer cells. The treatment is like a vaccine because it trains the body’s immune system to recognize and rapidly attack the source of disease.

Recruiting the patients

Caladrius has already dosed the first patient in the trial (which is double blinded so no one knows if the patient got the therapy or a placebo) and hopes to recruit 250 patients altogether.

This is the first Phase 3 trial that CIRM has funded so we’re obviously excited about its potential to help people battling this deadly disease.  In a recent news release David J. Mazzo, the CEO of Caladrius echoed this excitement, with a sense of cautious optimism:

“The dosing of the first patient in this Phase 3 trial is an important milestone for our Company and the timing underscores our focus on this program and our commitment to impeccable trial execution. We are delighted by the enthusiasm and productivity of the team at Jefferson University (where the patient was dosed) and other trial sites around the country and look forward to translating that into optimized patient enrollment and a rapid completion of the Phase 3 trial.”

And that’s the key now. They have the science. They have the funding. Now they need the patients. That’s why we are all working together to help Caladrius recruit patients as quickly as possible. Because their work perfectly reflects our mission of accelerating the development of stem cell therapies for patients with unmet medical needs.

You can learn more about what the study involves and who is eligible by clicking here.

Breast Cancer Tumors Recruit Immune Cells to the Dark Side

We rely on our immune system to stave off all classes of disease—but what happens when the very system responsible for keeping us healthy turns to the dark side? In new research published today, scientists uncover new evidence that reveals how breast cancer tumors can actually recruit immune cells to spur the spread of disease.

Some forms of breast cancer tumors can actually turn the body's own immune system against itself.

Some forms of breast cancer tumors can actually turn the body’s own immune system against itself.

Breast cancer is one of the most common cancers, and if caught early, is highly treatable. In fact, the majority of deaths from breast cancer occur because the disease has been caught too late, having already spread to other parts of the body, a process called ‘metastasis.’ Recently, scientists discovered that women who have a heightened number of a particular type of immune cells, called ‘neutrophils,’ in their blood stream have a higher chance of their breast cancer metastasizing to other tissues. But they couldn’t figure out why.

Enter Karin de Visser, and her team at the Netherlands Cancer Institute, who announce today in the journal Nature the precise link between neutrophil immune cells and breast cancer metastasis.

They found that some types of breast tumors are particularly nefarious, sending out signals to the person’s immune system to speed up their production of neutrophils. And then they instruct these newly activated neutrophils to go rogue.

Rather than attack the tumor, these neutrophils turn on the immune system. They especially focus their efforts at blocking T cells—the type of immune cells whose job is normally to target and attack cancer cells. Further examination in mouse models of breast cancer revealed a particular protein, called interleukin 17 (or IL17) played a key role in this process. As Visser explained in today’s news release:

“We saw in our experiments that IL17 is crucial for the increased production of neutrophils. And not only that, it turns out that this is also the molecule that changes the behavior of the neutrophils, causing them to become T cell inhibitory.”

The solution then, was clear: block the connection, or pathway, between IL17 and neutrophils, and you can thwart the tumor’s efforts. And when Visser and her team, including first author and postdoctoral researcher Seth Coffelt, did this they saw a significant improvement. When the IL17-neutrophil pathway was blocked in the mouse models, the tumors failed to spread at the same rate.

“What’s notable is that blocking the IL17-neutrophil route prevented the development of metastases, but did not affect the primary tumor,” Visser added. “So this could be a promising strategy to prevent the tumor from spreading.”

The researchers are cautious about focusing their efforts on blocking neutrophils, however, as these cells are in and of themselves important to stave off infections. A breast cancer patient with neutrophil levels that were too low would be at risk for developing a whole host of infections from dangerous pathogens. As such, the research team argues that focusing on ways to block IL17 is the best option.

Just last month, the FDA approved an anti-IL17 based therapy to treat psoriasis. This therapy, or others like it, could be harnessed to treat aggressive breast cancers. Says Visser:

“It would be very interesting to investigate whether these already existing drugs are beneficial for breast cancer patients. It may be possible to turn these traitors of the immune system back towards the good side and prevent their ability to promote breast cancer metastasis.”

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.


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.”

Stem Cell Stories that Caught our Eye: Skin Cells to Brain Cells in One Fell Swoop, #WeAreResearch Goes Viral, and Genes Helps Stem Cells Fight Disease

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.

Building a Better Brain Cell. Thanks to advances in stem cell biology, scientists have found ways to turn adult cells, such as skin cells, back into cells that closely resemble embryonic stem cells. They can then coax them into becoming virtually any cell in the body.

But scientists have more recently begun to devise ways to change cells from one type into another without first having to go back to a stem cell-like state. And now, a team from Washington University in St. Louis has done exactly that.

As reported this week in New Scientist, researcher Andrew Yoo and his team used microRNAs—a type of ‘signaling molecule’—to reprogram adult human skin cells into medium spiny neurons(MSNs), the type of brain cell involved in the deadly neurodegenerative condition, Huntington’s disease.

“Within four weeks the skin cells had changed into MSNs. When put into the brains of mice, the cells survived for at least six months and made connections with the native tissue,” explained New Scientist’s Clare Wilson.

This process, called ‘transdifferentiation,’ has the potential to serve as a faster, potentially safer alternative to creating stem cells.

#WeAreResearch Puts a Face on Science. The latest research breakthroughs often focus on the science itself, and deservedly so. But exactly who performed that research, the close-knit team who spent many hours at the lab bench and together worked to solve a key scientific problem, can sometimes get lost in the shuffle.

#WeAreResearch submission from The Thomson Lab at the University of California, San Francisco. This lab uses optogenetics, and RNAseq to probe cell fate decisions.

#WeAreResearch submission from The Thomson Lab at the University of California, San Francisco. This lab uses optogenetics, and RNAseq to probe cell fate decisions.

Enter #WeAreResearch, a new campaign led by the American Society for Cell Biology (ASCB) that seeks to show off science’s more ‘human side.’

Many California-based stem cell teams have participated—including CIRM grantee Larry Goldstein and his lab!

Check out the entire collection of submissions and, if you’re a member of a lab, submit your own. Prizes await the best submissions—so now’s your chance to get creative.

New Genes Help Stem Cells Fight Infection. Finally, UCLA scientists have discovered how stem cells ‘team up’ with a newly discovered set of genes in order to stave off infection.

Reporting in the latest issue of the journal Current Biology, and summarized in a UCLA news release, Julian Martinez-Agosto and his team describe how two genes—adorably named Yorkie and Scalloped—set in motion a series of events, a molecular Rube Goldberg device, that transforms stem cells into a type of immune system cell.

Importantly, the team found that without these genes, the wrong kind of cell gets made—meaning that these genes play a central role in the body’s healthy immune response.

Mapping out the complex signaling patterns that exist between genes and cells is crucial as researchers try and find ways to, in this case, improve the body’s immune response by manipulating them.

Harder, Better, Faster, Stronger: Scientists Work to Create Improved Immune System One Cell at a Time

The human immune system is the body’s best defense against invaders. But even our hardy immune systems can sometimes be outpaced by particularly dangerous bacteria, viruses or other pathogens, or even by cancer.

Salk Institute scientists have developed a new cellular reprogramming technique that could one day boost a weakened immune system.

Salk Institute scientists have developed a new cellular reprogramming technique that could one day boost a weakened immune system.

But what if we could give our immune system a boost when it needs it most? Last week scientists at the Salk Institute for Biological Sciences devised a new method of doing just that.

Reporting in the latest issue of the journal Stem Cells, Dr. Juan Carlos Izpisua Belmonte and his team announce a new method of creating—and then transplanting—white blood cells into laboratory mice. This new and improved method could have significant ramifications for how doctors attack the most relentless disease.

The authors achieved this transformation through the reprogramming of skin cells into white blood cells. This process builds on induced pluripotent stem cell, or iPS cell, technology, in which the introduction of a set of genes can effectively turn one cell type into another.

This Nobel prize-winning approach, while revolutionary, is still a many months’ long process. In this study, the Salk team found a way to shorten the cellular ‘reprogramming’ process from several months to just a few weeks.

“The process is quick and safe in mice,” said Izpisua Belmonte in a news release. “It circumvents long-standing obstacles that have plagued the reprogramming of human cells for therapeutic and regenerative purposes.”

Traditional reprogramming methods change one cell type, such as a skin cell, into a different cell type by first taking them back into a stem cell-like, or ‘pluripotent’ state. But here, the research team didn’t take the cells all the way back to pluripotency. Instead, they simply wiped the cell’s memory—and gave it a new one. As first author Dr. Ignacio Sancho-Martinez explained:

“We tell skin cells to forget what they are and become what we tell them to be—in this case, white blood cells. Only two biological molecules are needed to induce such cellular memory loss and to direct a new cell fate.”

This technique, which they dubbed ‘indirect lineage conversion,’ uses the molecule SOX2 to wipe the skin cell’s memory. They then use another molecule called miRNA 125b to reprogram the cell into a white blood cell.

These newly generated cells appear to engraft far better than cells derived from traditional iPS cell technology, opening the door to therapies that more effectively introduce these immune cells into the human body. As Sanchi-Martinez so eloquently stated:

“It is fair to say that the promise of stem cell transplantation is now closer to realization.”

Creaky Cell Machinery Affects the Aging Immune System, CIRM-Funded Study Finds

Why do our immune systems weaken over time? Why are people over the age of 60 more susceptible to life-threatening infections and many forms of cancer? There’s no one answer to these questions—but scientists at the University of California, San Francisco (UCSF), have uncovered an important mechanism behind this phenomenon.

Reporting in the latest issue of the journal Nature, UCSF’s Dr. Emmanuelle Passegué and her team describe how blood and immune cells must be continually replenished over the lifetime of an organism. As that organism ages the complex cellular machinery that churns out new cells begins to falter. And when that happens, the body can become more susceptible to deadly infections, such as pneumonia.

As Passegué so definitively put it in a UCSF news release:

“We have found the cellular mechanism responsible for the inability of blood-forming cells to maintain blood production over time in an old organism, and have identified molecular defects that could be restored for rejuvenation therapies.”

The research team, which examined this mechanism in old mice, focused their efforts on hematopoetic stem cells—a type of stem cell that is responsible for producing new blood and immune cells. These stem cells are present throughout an organism’s lifetime, regularly dividing to preserve their own numbers.

Molecular tags of DNA damage are highlighted in green in blood-forming stem cells. [Credit: UCSF]

Molecular tags of DNA damage are highlighted in green in blood-forming stem cells. [Credit: UCSF]

But in an aging organism, these cells’ ability to generate new copies is not as good as it used to be. When the research team dug deeper they found a key bit of cellular machinery, called the mini-chromosome maintenance helicase, breaks down. When that happens, the DNA inside the cell can’t replicate itself properly—and the newly generated cell is not running on all cylinders.

One of the first things that these old stem cells lose as a result is their ability to make B cells. B cells, a key component of the immune system, normally make antibodies that fight infection. As B cell numbers dwindle in an aging organism, so too does their ability to fight infection. As a result the organism’s risk for contracting dangerous illnesses skyrockets.

This research, which was funded in part by CIRM, not only informs what goes wrong in an aging organism at the molecular level, but also points to new targets that could keep these stem cells functioning at full capacity, helping promote so-called ‘healthy aging.’ As Passegué added:

“Everybody talks about healthier aging. The decline of stem-cell function is a big part of age-related problems. Achieving longer lives relies in part on achieving a better understanding of why stem cells are not able to maintain optimal functioning.”

Out with the Old and in with the New: Starvation Sparks Stem Cells to Replenish Immune System

New research from California scientists has revealed a startling side effect to prolonged starvation, or fasting.

In the latest issue of the journal Cell Stem Cell, scientists from the University of Southern California describe how fasting triggers the human immune system to flush out old, damaged cells and replace them with new ones. This marks the first time that this phenomenon has been directly observed, and has major implications for diseases associated with a declining immune system, including a variety of age-related conditions and cancer chemotherapy.

Scientists have discovered how cycles of prolonged fasting can help flush out damaged immune system cells.

Scientists have discovered how cycles of prolonged fasting can help flush out damaged immune system cells.

In lab experiments first in animal models, and then followed by a Phase 1 human clinical trial, the research team found that regular cycles of fasting, each lasting two to four days, triggered the immune system to flush out immune cells. Much to the team’s surprise, however, they also found that these fasting cycles also triggered stem cells—which had been dormant—to spring into action and produce a fresh supply.

While initially unexpected, these findings made sense to the team. As corresponding author Dr. Valter Longo explained in today’s news release:

“When you starve, the system tries to save energy, and one of the things it can do to save energy is to recycle a lot of the immune cells that are not needed, especially those that may be damaged. What we started noticing in both our human work and animal work is that the white blood cell count goes down with prolonged fasting. Then when you re-feed, the blood cells come back. So we started thinking, well, where does it come from?”

Scientists have long known that when fasting, your body turns to its reserves for nutrients, using up stores of glucose and fat. At the same time, your body also breaks down white blood cells—the major component of the immune system.

So, Longo and his team mapped precisely how this change takes place. They observed that prolonged fasting also reduced levels of an enzyme called PKA. In a previous study, the team had found a link between reduced PKA levels and increased longevity in simple organisms. Research by other groups also found a connection between PKA and the ability of stem cells to self-renew. In this study, the team further defined that relationship. As Longo continued:

“PKA is the key gene that needs to shut down in order for these stem cells to switch into regenerative mode. And the good news is that the body got rid of the parts of the system that might be damaged or old…during fasting. Now if you start with a system heavily damaged, fasting cycles can generate, literally, a new immune system.”

These findings are particularly encouraging with regards to chemotherapy, which has the unfortunate side effect of often damaging the body’s immune system. But if the patient also participates in cycles of fasting, Longo and his team hypothesize that this could help repair their immune system at a much faster pace, improving their quality of life during treatment.

In order to test this hypothesis, the team then turned to the Phase 1 human clinical trial. They instructed patients currently undergoing chemotherapy to fast for a period of 72 hours. The team found that this fasting did protect against at least some of the toxic effects of chemotherapy treatment.

The next steps, says Longo, are to conduct additional experiments in both animal models and clinical trials. But the team is optimistic that these results could apply beyond chemotherapy.

“We are investigating the possibility that these effects are applicable to many different systems and organs, not just the immune system.”