Enzyme Inhibitor Combined with Chemotherapy Delays Glioblastoma Growth

 In animal experiments, a human-derived glioblastoma significantly regressed when treated with the combination of an experimental enzyme inhibitor and the standard glioblastoma chemotherapy drug, temozolomide.

The regression seen in this combination therapy of temozolomide and the inhibitor SLC-0111 — which targets the enzyme carbonic anhydrase 9, or CA9 — was greater than that seen with either SLC-0111 or temozolomide alone, says research leader Anita Hjelmeland, Ph.D., assistant professor in the Department of Cell, Developmental and Integrative Biology at the University of Alabama at Birmingham.

“Our experiments strongly suggest that a strategy to target a carbonic anhydrase that is increased in glioblastoma, CA9, will improve temozolomide efficacy,” Hjelmeland said. “We believe the drug combination could improve patient outcomes in glioblastomas sensitive to chemotherapy.”

Glioblastoma is the most common primary brain tumor seen in adults. Half of the tumors recur less than seven months after undergoing the standard treatment of surgery, temozolomide and radiation. The median survival after diagnosis of this deadly cancer is 12 to 14 months. Thus, new approaches to therapy are urgently needed.

Solid tumors like glioblastoma create microenvironments within and around themselves. A common condition is hypoxia, a shortage of oxygen as the tumor outgrows its blood supply. Tumor cells shift to making their energy through glycolysis, a method of metabolism that does not require oxygen. Glycolysis, in turn, changes the acid-base balance at the tumor — the extracellular space becomes more acidic and the tumor cell interiors become more alkaline, adapting to this change.

In the face of this hypoxia and acid stress, tumor cells over-produce CA9, a membrane enzyme that converts carbon dioxide and water to bicarbonate and protons. This reaction aids maintenance of the altered acid-base balance in the tumor microenvironment.

Thus, CA9 is a possible therapeutic target, and the inhibitor SLC-0111 shows more than 100-fold specificity against CA9, versus two other forms of human carbonic anhydrases, CA1 or CA2. Furthermore, collaborators on this project have previously shown that SLC-0111 exhibits effectiveness against breast cancer xenografts in animals. SLC-0111 has been tested in Phase I clinical safety trials sponsored by Welichem Biotech Inc. in Canada for patients with advanced solid tumors.

The research team led by Hjelmeland and co-first authors Nathaniel Boyd, Ph.D., and Kiera Walker, both working in Hjelmeland’s UAB lab, studied glioma cells in cell-culture that were derived from an aggressive pediatric primary glioblastoma and from an adult recurrent tumor. The researchers also studied the tumor in mice, using the adult recurrent glioblastoma.

One reason for recurrence of glioblastoma is a therapeutically resistant sub-population of glioma cells known as brain tumor initiating cells. Part of the focus of the Hjelmeland team was to look at the effect of the combination therapy on that subset of glioblastoma cells.

The researchers found that the combined treatment with temozolomide and SLC-0111 in cell culture experiments: 1) reduced glioblastoma cell growth, 2) induced arrest of the cell-division cell cycle by creating breaks in DNA, 3) shifted the tumor metabolism and intracellular acid-base balance by decreasing metabolic intermediates, and 4) inhibited enrichment of brain tumor initiating cells.

In experiments with mice, the combined treatment with temozolomide and SLC-0111: 1) delayed tumor growth of a patient-derived, recurrent glioblastoma xenograft implanted beneath the skin of immunocompromised mice, as compared to temozolomide alone, and 2) improved survival of the mice when the xenograft was implanted in the brain, a placement that more closely models glioblastoma in patients.

“Clinical trials in glioblastoma often initiate with patients that have a tumor recurrence, and we have demonstrated in vivo efficacy for SLC-0111 with temozolomide in a recurrent glioblastoma,” the researchers wrote in their study, published in JCI Insight. “Therefore, our data strongly suggest the translational potential of SLC-0111 for glioblastoma therapy.”

“With funds from the Southeastern Brain Tumor Foundation,” Hjelmeland said, “we continue to determine whether there are subtypes of glioblastomas that are most likely to respond to combinatorial therapy.

Bioengineered Soft Microfibers Improve T-Cell Production

Columbia engineers bioengineer soft microfibers to improve T-cell production.

T cells play a key role in the body’s immune response against pathogens. As a new class of therapeutic approaches, T cells are being harnessed to fight cancer, promising more precise, longer-lasting mitigation than traditional, chemical-based approaches. These “living drugs” are poised to transform medicine, with a growing number of cellular therapies receiving FDA-approval.

A current bottleneck in these approaches and other Adoptive T-cell Therapies (ACTs) is the production of sufficient numbers of high quality T cells. As a starting material, cells are isolated from the patient and then modified and grown outside the body in a bioreactor. This is still a new manufacturing challenge in medicine, and lack of a therapeutic number of cells is a frequent point of failure in ACT. In addition to technical challenges faced in consistent production of cells, T cells from patients undergoing treatment for cancer often show reduced function due to the disease, and are particularly difficult to grow.

A Columbia Engineering team has developed a new method for improving T-cell manufacture by focusing on the materials involved in this process. The team is a collaboration between Biomedical Engineering faculty Lance C. Kam and Helen H. Lu, whose research programs include immune engineering and smart biomaterial design. Their study, which is published today in Advanced Biosystems, uses a polymer mesh to activate the T cells, a critical step for their production. This approach simplifies processing compared to systems in use today. In addition, making the fibers out of a mechanically soft material improved T-cell growth, outperforming the current gold standard on several fronts.

“Our report shows that this soft mesh material increases the number of functional cells that can be produced in a single step,” Kam says. “In fact, our system provided nearly an order of magnitude more cells in a single process. What’s especially exciting is that we’ve been able to expand cells isolated from patients undergoing treatment for leukemia. These cells are often very difficult to activate and expand, and this has been a barrier to using cellular immunotherapy for the people who need it.”

In testing the effect of a softer material on T-cell production, the team was inspired by the field of mechanobiology. Researchers have known that other cell types can sense the mechanical stiffness of a material. For example, the rigidity of a material used to culture stem cells can direct differentiation, with a softer material promoting production of neuron while a stiffer substrate encourages bone cell differentiation. This effect can be as strong as the chemicals normally used to direct differentiation. However, a similar effect was unexpected in T cells for activation.

“This makes sense for cells normally involved in force-related activities, like muscle cells or fibroblasts that are involved in wound closure and healing. Our group was one of the first to explore this possibility for T cells, which are not associated with such functions,” Kam notes. These early experiments, involving his Microscale Biocomplexity Laboratory group, discovered that T-cells can sense the mechanical rigidity of the materials commonly used in the laboratory. To turn this into a clinically useful system, his group partnered with Lu’s Biomaterials and Interface Tissue Engineering Laboratory to create a microfiber-based platform.

Beyond simplifying the process of cell expansion and improving T-cells expansion, Kam and Lu envision that the mesh platform will have applications beyond immunotherapy. They are refining their platform and exploring how T cells from cancer patients respond to their materials. Says Lu, “It is truly exciting to see how these bioinspired matrices can direct cell function and be successfully used for T-cell therapy.”

Two New Breast Cancer Genes Emerge from Lynch Syndrome Gene Study

The findings suggest that genetic screening for breast cancer should be expanded to include MSH6 and PMS2

Researchers at Columbia University Irving Medical Center and NewYork-Presbyterian have identified two new breast cancer genes. Having one of the genes—MSH6 and PMS2—approximately doubles a woman’s risk of developing breast cancer by age 60.

The study, in collaboration with GeneDx, a genetic testing company, was published online today in Genetics in Medicine.

The two genes were previously known to cause Lynch syndrome, an inherited condition that raises the risk of colorectal, ovarian, stomach, and endometrial cancer. Lynch syndrome is the most common inherited cause of colorectal cancer, accounting for about 3 percent of newly diagnosed cases. One in 440 Americans has a gene variant that causes Lynch syndrome.

Researchers had suspected that Lynch syndrome genes may also cause breast cancer. Some studies had found a link, whereas others had not.

“People with Lynch syndrome aren’t thinking they may also be at risk for breast cancer,” said Wendy Chung, MD, PhD, the Kennedy Family professor of pediatrics (in medicine) at Columbia University Irving Medical Center, clinical geneticist at NewYork-Presbyterian/Columbia, and the study’s senior author. “Given the fact that genomic analysis is becoming more common in patients with a personal or family history of cancer, we have an opportunity to do more targeted breast cancer screening in women who carry any of the genes associated with risk for this disease.”

The researchers analyzed a database of more than 50,000 women who had undergone multi-gene hereditary cancer testing between 2013 and 2015. Of these, 423 women had a mutation in one of the four genes that cause Lynch syndrome: MLH1, MSH2, MSH6, and PMS2.

Additional analyses revealed that women with a mutation in two specific Lynch syndrome genes—MSH6 and PMS2—had a two-fold higher risk of breast cancer compared to women in the general population.

Based on the incidence of cancer in the study population, the researchers calculated that about 31 to 38 percent of women with cancer-causing MSH6 and PMS2 variants will develop breast cancer, compared to around 15 percent of women in the general population.

“The new study suggests MSH6 and PMS2 should be added to the list of genes to screen for when there is a history of breast cancer,” said Dr. Chung, who is also director of the clinical genetics program at NewYork-Presbyterian/Columbia. “Screening for these genes also would give these families potentially life-saving information to prevent colon cancer by encouraging individuals with the genes to increase the frequency of their colonoscopies.”

Currently, testing for Lynch syndrome genes is generally only done when someone has a personal or family history of colon or uterine cancer.

Dr. Chung added, “Given that Lynch syndrome is not rare in the general population, this finding has the potential to impact tens of thousands of people in the U.S. and could change standard practice related to one of the most common cancer predisposition syndromes.”

The study is titled, ‘MSH6 and PMS2 Germline Pathogenic Variants Implicated in Lynch Syndrome are Associated with Breast Cancer.’

Genetic discovery may help better identify children at risk for type 1 diabetes

Six novel chromosomal regions identified by scientists leading a large, prospective study of children at risk for type 1 diabetes will enable the discovery of more genes that cause the disease and more targets for treating or even preventing it.

The TEDDY study’s international research team has identified the new gene regions in young people who have already developed type 1 diabetes or who have started making antibodies against their insulin-producing cells, often a precursor state to the full-blown disease that leads to a lifetime of insulin therapy.

Their analysis of 5,806 individuals published in the Journal of Autoimmunity also confirmed three regions already associated with one of those related conditions.

“We want to build a more precise profile of who will get this disease and when,” says Dr. Jin-Xiong She, director of the Center for Biotechnology and Genomic Medicine at the Medical College of Georgia at Augusta University, principal investigator of TEDDY’s Georgia/Florida site and the study’s corresponding author.

In keeping with their theory that two subtypes of type 1 diabetes will become clear from longitudinal studies of those at risk, the international TEDDY team also found different chromosomal regions were associated with which autoantibody shows up first in a patient, a sign his immune system is turning on his pancreas.

They looked at two top autoantibodies: one directly against insulin, called IAA, and one called GADA, against the enzyme glutamate decarboxylase, which regulates the insulin-producing beta cells in the pancreas. About 90 percent of patients with type 1 diabetes have one or the other autoantibody first and many eventually end up with both, She says. The second autoantibody may surface in a few days or even years later.

“There is mounting evidence that we have at least two major subtypes of type 1 diabetes, based on the autoantibodies children have. Now we have found a genetic basis that supports that,” says She, Georgia Research Alliance Eminent Scholar in Genomic Medicine.

TEDDY – The Environmental Determinants of Diabetes in the Young – is an international initiative following almost 9,000 children for 15 years in a strategic and rare opportunity to watch how genetics and environmental factors collide to cause disease, She says. An original goal of TEDDY was to better determine which genetic variations correlate with progression or lack of progression to type 1 diabetes.

For this particular pursuit, they focused on the 5,806 Caucasian TEDDY participants, because of genetic differences in different ethnic groups. They also focused on non-HLA genes, says Dr. Ashok Sharma, MCG bioinformatics expert and the study’s first author.

Most genes known to be associated with type 1 diabetes – including those currently considered the top two high-risk genes, which are the ones TEDDY screens for – are classified as human leukocyte antigen, or HLA genes. It’s a logical association since HLA genes regulate our immune system, says Sharma.

But in their comprehensive effort to better identify children at highest risk of disease – and ideally one day intervene – this particular search focused on non-HLA genes. “By study design we were looking for them,” Sharma says.

“With HLA genes you can achieve a certain level of accuracy in identifying high-risk individuals,” says She. “But if we can add additional genes into the screening, we can refine the prediction of the disease, we can increase the accuracy, we can probably even identify higher percentages of at-risk individuals.”

“It’s not monogenic, there are many genes involved,” Sharma says of type 1 diabetes, a condition that affects 1 in 300 people in the United States by age 18, according to the National Institutes of Health.

Which of those genes are involved also varies by individual. Sharma and She note the reality that not all patients with the high-risk genes even get the disease, although they still don’t know why.

One of the many points they hope TEDDY clarifies is if or how these genetics along with environmental factors – like childhood infections or even what children eat – conspire to cause actual disease. Genetic factors are comparatively easier to identify, and should also help identify environmental factors, they say.

For this study, the scientists also started with 176,586 SNPs, or single nucleotide polymorphisms. A nucleotide is a basic building block of our genetic information. In the case of DNA, those are A, C, T and G, chemical bases that can be arranged in seemingly endless potential orders. SNPs are genetic variations – one letter replaced by another – that scientists are using increasingly to figure out which occur more or less often in people with a certain condition or disease.

The SNPs examined by TEDDY scientists were already associated with other autoimmune diseases like rheumatoid arthritis or celiac disease, but not type 1 diabetes, Sharma says. They determined which of these SNPs are different in TEDDY participants who had developed type 1 diabetes versus those who had Islet cell autoantibodies versus those who still had neither.

Previous research has shown that the same genes are not always associated with IA and actual type 1 diabetes.

In fact, while Islet cell autoantibodies, or IA, are considered a red flag for type 1 diabetes, not every child with IA will progress to full-blown disease, She says, although multiple autoantibodies definitely increase that risk. In fact, different genes may play a role in IA development while others play a role in disease progression, the TEDDY scientists write.

While the SNPs themselves may or may not have a direct functional consequence, they are in close proximity to a gene that does, says She. “It’s a marker,” he says, that will enable the scientists to more efficiently and effectively identify causative genes.

“We are using SNPs but not as an endpoint,” Sharma notes. “We want to find out the genes which are there,” a focal point for the work now underway.

Key to the work already complete, is how closely and long TEDDY participants are followed. Normally gene identification starts with what is called a case-control design, in which genetic variations are compared between patients with a condition and healthy individuals, to look for differences that may contribute to the disease.

While standard cross-sectional, or case-control studies haven’t shown a huge impact from non-HLA genes, they only provide a “snapshot’ of what is happening with both patients and controls alike, the scientists say. With the prospective and longitudinal TEDDY, the scientists are literally watching the disease occur – or not – in high-risk young people.

In fact, this is the first major study regarding gene identification for any disease that uses this sort of longitudinal information, She says.

As with many things, timing is everything, and the TEDDY perspective sharpens the search, particularly for important non-HLA genes by adding the “time to disease” perspective, She says.

Photographed: Drs. Jin-Xiong She (left) and Ashok Sharma

Study advances gene therapy for glaucoma

While testing genes to treat glaucoma by reducing pressure inside the eye, University of Wisconsin-Madison scientists stumbled onto a problem: They had trouble getting efficient gene delivery to the cells that act like drains to control fluid pressure in the eye.

Genes can’t work until they enter a cell.

Glaucoma, one of the most common blinding diseases, is caused by excess pressure inside the eye, usually due to a clog in the fluid drain. “Most glaucoma can be treated with daily drug treatment,” says Paul Kaufman, professor of ophthalmology and visual sciences at the University of Wisconsin-Madison. “Replacement genes could, theoretically, restore normal fluid flow for years on end, without requiring daily self-administration of eye drops that is inconvenient and may have local or even systemic side effects.”

In a study published today in the scientific journal Investigative Ophthalmology and Visual Science, Kaufman and Curtis Brandt, a fellow professor of ophthalmology and visual sciences at UW-Madison, showed an improved tactic for delivering new genes into the drain, called the trabecular meshwork.

The colleagues have been testing a vector based on feline immunodeficiency virus (FIV) to deliver the genes. Like the related c, FIV can insert genes into the host’s DNA. The eye’s innate defenses against FIV, however, interfered with the delivery.

Virus particles contain genes wrapped in a protein coat and then a lipid membrane. After the virus enters the cell and sheds its membrane, defensive molecules from the host can “drag the virus particle to the cell’s garbage disposal, called the proteasome, where it is degraded,” Brandt says. “We wanted to know if temporarily blocking the proteasome could prevent the destruction of the gene delivery vector and enhance delivery.”

In the current study, FIV virus carrying a marker protein was placed on cells of the trabecular meshwork, with or without a chemical that blocks proteasomes.

Above a dosage threshold, the treatment roughly doubled the transfer of genes entering the target cells, Brandt says. The new genes also spread more uniformly across the meshwork tissue. Delivering more copies of the gene should give a greater therapeutic effect, opening the meshwork drain and reducing pressure inside the eye.

The present study concerns the tools for transferring genes, not the genes themselves, Brandt says. But even before the current study, he says he and Kaufman “have already identified at least two genes that could unplug the drain.”

In the long struggle to replace genes and cure disease, “eyes have been one of the big success stories,” Brandt says. A blinding eye disease called Leber’s congenital amaurosis damages the function of cells that keep the light-sensitive cells healthy; replacing the mutated genes has preserved and even improved vision in young patients. Approval for this gene therapy is now pending at the Food and Drug Administration.

To forestall danger from injecting a virus, “We take out pretty much all of the virus’ genes, so it has no chance to replicate and spread from where it’s initially injected,” says Brandt.

Although the technique does interfere with the anti-viral defense in the eye, the effect is temporary. “You encounter the drug once, then it is metabolized, and the innate inhibition is lost,” Brandt says.

“We have shown that this strategy does work in eye organ culture,” Brandt says. “Once we do further work on efficiency and identify which gene to deliver, then we are probably ready to move toward clinical trials.”

Merek’s KEYTRUDA Improved Overall Survival in Patients with Non-small Cell Lung Cancer

Merck announced that the pivotal Phase 3 KEYNOTE-189 trial investigating KEYTRUDA (pembrolizumab), Merck’s anti-PD-1 therapy, in combination with pemetrexed (Alimta) and cisplatin or carboplatin, for the first-line treatment of patients with metastatic non-squamous non-small cell lung cancer (NSCLC), met its dual primary endpoints of overall survival (OS) and progression-free survival (PFS). Based on an interim analysis conducted by the independent Data Monitoring Committee, treatment with KEYTRUDA in combination with pemetrexed plus platinum chemotherapy resulted in significantly longer OS and PFS than pemetrexed plus platinum chemotherapy alone. The safety profile of KEYTRUDA in this combination was consistent with that previously observed.

Results from KEYNOTE-189 will be presented at an upcoming medical meeting and submitted to regulatory authorities.

“KEYNOTE-189 showed significant improvement in overall survival and progression-free survival for patients receiving KEYTRUDA in the first-line setting in combination with traditional chemotherapy, compared with those receiving chemotherapy alone,” said Dr. Roger M. Perlmutter, president, Merck Research Laboratories. “We are deeply grateful to the KEYNOTE-189 patients and investigators for their important contributions to this landmark study, and we look forward to presenting the data in the near future.”

KEYNOTE-189 is a randomized, double blind, placebo controlled, Phase 3 study (ClinicalTrials.gov, NCT02578680) investigating KEYTRUDA (pembrolizumab) in combination with pemetrexed and cisplatin or carboplatin compared with pemetrexed and cisplatin or carboplatin alone in patients with advanced or metastatic nonsquamous non-small cell lung cancer, regardless of PD-L1 expression. Patients had no EGFR or ALK genomic tumor aberrations, and had not previously received systemic therapy for advanced disease. The KEYNOTE-189 study was done in collaboration with Eli Lilly and Company, the makers of pemetrexed. The dual primary endpoints are OS and PFS; secondary endpoints include overall response rate (ORR) and duration of response (DOR). The study enrolled 614 patients randomized 2:1 to receive either KEYTRUDA (200 mg fixed dose every three weeks) plus pemetrexed (500 mg/m) (with vitamin supplementation) plus cisplatin (75 mg/m2) or carboplatin AUC 5 on day 1 every 3 weeks (Q3W) for 4 cycles followed by KEYTRUDA 200 mg plus pemetrexed (500 mg/m) Q3W or KEYTRUDA placebo 200 mg plus pemetrexed (500 mg/m2) (with vitamin supplementation) plus cisplatin (75 mg/m2) or carboplatin AUC 5 on day 1 every 3 weeks (Q3W) for 4 cycles followed by KEYTRUDA placebo 200 mg plus pemetrexed (500 mg/m2) Q3W until disease progression, unacceptable toxicity, physician decision or consent withdrawal. Patients on the control arm who experienced disease progression, verified by central independent review, were permitted to undergo treatment assignment unblinding and crossover to receive open-label KEYTRUDA.

More Evidence of Link Between Severe Gum Disease and Cancer Risk

Data collected during a long-term health study provides additional evidence for a link between increased risk of cancer in individuals with advanced gum disease, according to a new collaborative study led by epidemiologists Dominique Michaud at Tufts University School of Medicine and Elizabeth Platz of the Johns Hopkins Bloomberg School of Public Health and Kimmel Cancer Center.

The study, published in the Journal of the National Cancer Institute, used data from comprehensive dental exams performed on 7,466 participants from Maryland, Minnesota, Mississippi, and North Carolina, as part of their participation in the Atherosclerosis Risk in Communities (ARIC) study who were then followed from the late 1990s until 2012. During the follow-up period, 1,648 new cancer cases were diagnosed.

The research team found a 24 percent increase in the risk of developing cancer among participants with severe periodontitis, compared to those with mild to no periodontitis at baseline. Among patients who had no teeth—which can be a sign of severe periodontitis—the increase in risk was 28 percent. The highest risk was observed in cases of lung cancer, followed by colorectal cancer.

When the researchers did sub-group analyses, they found that participants with severe periodontal disease had more than double the risk of developing lung cancer, compared with no/mild periodontitis. An 80 percent increase in risk of colon cancer observed for participants who were edentulous at baseline, which is consistent with prior findings, and among never smokers, a two-fold higher risk was noted for participants with severe periodontitis, compared to those who had no/mild periodontitis.

“This is the largest study addressing the association of gum disease and cancer risk using dental examinations to measure gum disease prior to cancer diagnosis,” said first and corresponding author Dominique Michaud, Sc.D., professor of public health and community medicine at Tufts University School of Medicine. “Additional research is needed to evaluate if periodontal disease prevention and treatment could help alleviate the incidence of cancer and reduce the number of deaths due to certain types of cancer.”

Michaud noted that the findings were particularly interesting in light of research, including a recent study in Science, which determined that colorectal cancer tissues contain bacteria that are present in the mouth, including bacteria that have been associated with periodontal disease.

The researchers also uncovered a small increase in the risk of pancreatic cancer in patients with severe periodontitis. Although not significant statistically, the association has been seen in other similar studies, including a number of studies led by Michaud of Tufts.

The research team accounted for the impact of smoking among the participants, since people who smoke are more likely to get periodontal disease, and smoking raises the risk of lung and colon cancers.

“When we looked at data for the people who had never smoked, we also found evidence that having severe periodontal disease was related to an increased risk of lung cancer and colorectal cancer,” said Elizabeth Platz, Sc.D., deputy chair of the department of epidemiology at the Johns Hopkins Bloomberg School of Public Health and co-leader of the Cancer Prevention and Control Program at the Johns Hopkins Kimmel Cancer Center.

The ARIC data were especially useful to study because unlike most previous research linking gum disease and cancer risk, periodontitis cases were determined from dental examinations performed as part of the ARIC study rather than participants’ self-reports of the disease. The dental exams provided detailed measurements of the depth of the pocket between the gum and tooth in several locations in the mouth. The ARIC data include both Caucasian and African-American participants.

The researchers found no links between increased risk of breast, prostate or blood/lymphatic cancer and periodontitis. The link between periodontitis and increased cancer risk was weaker or not apparent in African-American participants from the ARIC study, except in cases of lung and colorectal cancer. “Additional research is needed to understand cancer-site specific and racial differences in findings,” wrote the authors. The researchers caution that the study was limited in size for subgroup analyses, and less common cancers. The findings, however, suggest the need for further study.

Michaud and Platz said the study also points to the importance of expanding dental insurance to more individuals. “Knowing more about the risks that come about with periodontal disease might give more support to having dental insurance in the way that we should be offering health insurance to everyone,” Platz said.

Advanced gum disease, also called periodontitis, is caused by bacterial infection that damages the soft tissue and bone that support the teeth. Previous research has shown a link between periodontitis and increased cancer risk, although the mechanism connecting the two diseases is still uncertain.

Flipping the Switch: Dietary Fat, Changes in Fat Metabolism May Promote Prostate Cancer Metastasis

Prostate tumors tend to be what scientists call “indolent” – so slow-growing and self-contained that many affected men die with prostate cancer, not of it. But for the percentage of men whose prostate tumors metastasize, the disease is invariably fatal. In a set of papers out today in the journals Nature Genetics and Nature Communications, researchers at the Cancer Center at Beth Israel Deaconess Medical Center (BIDMC) shed new light on the genetic mechanisms that promote metastasis in the mouse model and also implicated the typical Western high-fat diet as a key environmental factor driving metastasis.

“Although it is widely postulated that a Western diet can promote prostate cancer progression, direct evidence supporting a strong association between dietary lipids and prostate cancer has been lacking,” said first author Ming Chen, PhD, a research fellow in the laboratory of Pier Paolo Pandolfi, MD, PhD, Director of the Cancer Center and Cancer Research Institute at BIDMC.

Epidemiological data links dietary fats (and obesity) to many types of cancer, and rates of cancer deaths from metastatic cancers including prostate cancer are much higher in the United States than in nations where lower fat diets are more common. While prostate cancer affects about ten percent of men in Asian nations, that rate climbs to about 40 percent when they immigrate to the U.S., mirroring the rates among the native born U.S. population. That points to an environmental culprit that may work in concert with genetic factors to drive this aggressive, fatal disease.

“The progression of cancer to the metastatic stage represents a pivotal event that influences patient outcomes and the therapeutic options available to patients,” said senior author Pandolfi. “Our data provide a strong genetic foundation for the mechanisms underlying metastatic progression, and we also demonstrated how environmental factors can boost these mechanisms to promote progression from primary to advanced metastatic cancer.”

The tumor suppressor gene PTEN is known to play a major role in prostate cancer; its partial loss occurs in up to 70 percent of primary prostate tumors. Its complete loss is linked to metastatic prostate disease, but animal studies suggest the loss of PTEN alone is not enough to trigger progression. Pandolfi and colleagues sought to identify an additional tumor suppressing gene or pathway that may work in concert with PTEN to drive metastasis.

Looking at recent genomic data, Pandolfi and colleagues noticed that another tumor suppressor gene, called PML, tended to be present in localized (non-metastatic) prostate tumors, but was absent in about a third of metastatic prostate tumors. Moreover, about 20 percent of metastatic prostate tumors lack both PML and PTEN.

When they compared the two types of tumor – the localized ones lacking only the PTEN gene versus the metastatic tumors lacking both genes – the researchers found that the metastatic tumors produced huge amounts of lipids, or fats. In tumors that lacked both PTEN and PML tumor suppressing genes, the cells’ fat-production machinery was running amok.

“It was as though we’d found the tumors’ lipogenic, or fat production, switch,” said Pandolfi. “The implication is, if there’s a switch, maybe there’s a drug with which we can block this switch and maybe we can prevent metastasis or even cure metastatic prostate cancer,” he added.

Such a drug already exists. Discovered in 2009, a molecule named “fatostatin” is currently being investigated for the treatment of obesity. Pandolfi and colleagues tested the molecule in lab mice. “The obesity drug blocked the lipogenesis fantastically and the tumors regressed and didn’t metastasize.”

In addition to opening the door to new treatment for metastatic prostate cancer, these findings also helped solve a long-standing scientific puzzle. For years, researchers had difficulty modeling metastatic prostate cancer in mice, making it hard to study the disease in the lab. Some speculated that mice simply weren’t a good model for this particular disease. But the lipid production finding raised a question in Pandolfi’s mind.

“I asked, ‘What do our mice eat?’” Pandolfi recalled.

It turned out, the mice ate a vegetable-based chow – essentially a low-fat vegan diet that bore little resemblance to that of the average American male. When Pandolfi and colleagues increased the levels of saturated fats – the kind found in fast food cheeseburgers and fries – in the animals’ diet, the mice developed aggressive, metastatic tumors.

The findings could result in more accurate and predictive mouse models for metastatic prostate cancer, which in turn could accelerate discovery of better therapies for the disease. Additionally, physicians could soon be able to screen their early-stage prostate cancer patients for those whose tumors lack both PTEN and PML tumor suppressing genes, putting them at increased risk for progressing to metastatic disease. These patients may be helped by starving these tumors of fat either with the fat-blocking drug or through diet.

“The data are tremendously actionable, and they surely will convince you to change your lifestyle,” Pandolfi said.

Photographed: Pier Paolo Pandolfi, MD, PhD, Director of the Cancer Center and Cancer Research Institute at BIDMC

Placental Cells Significantly Inhibit Cancer Cell Growth in Newly Published Study

According to the peer-reviewed article in the journal Scientific Reports, placenta-derived cells called PLX cells, exhibit a strong inhibitory effect on various lines of breast, colorectal, kidney, liver, lung, muscle and skin cancers. The research was conducted over more than two years by Pluristem Therapeutics, Inc., a Haifa-based biotechnology company.

The article titled “Human Placental-Derived Adherent Stromal Cells Co-Induced with TNF‑a and IFN‑g Inhibit Triple-Negative Breast Cancer in Nude Mouse Xenograft Models” is based on studies which examined the effect of Pluristem Therapeutic‘s PLX cells that had been induced with tumor necrosis factor alpha (TNF-a) and interferon-gamma (IFN-g), on the proliferation of over 50 lines of human cancerous cells. The induction of the cells was carried out by adjusting their manufacturing process in order to transiently alter their secretion profile.

Data from the first study showed that the modified PLX cells exhibited an anti-proliferative effect on 45% of the tested cancer cell lines, with a strong inhibitory effect on various lines of breast, colorectal, kidney, liver, lung, muscle and skin cancers. Comprehensive bioinformatics analysis identified common characteristics of the cancer cell lines inhibited by PLX cells. This knowledge could potentially be used in the future for screening patients’ tumors to identify those patients most likely to show a positive response to treatment with PLX cells.

Based on these promising results, Pluristem conducted a pre-clinical study of female mice harboring human triple negative breast cancer (TNBC). TNBC is an aggressive form of breast cancer that does not respond to standard hormonal therapy due to a lack of estrogen and progesterone receptors. Current treatment for TNBC consists of a combination of surgery, radiation therapy, and chemotherapy, and yet the prognosis remains poor for patients with this type of breast cancer. In this study, weekly intramuscular (IM) injections of the induced PLX cells produced a statistically significant reduction (p= 0.025) in mean tumor size in the treated group compared with the untreated group, with 30% of the treated mice exhibiting complete tumor remission. In addition, a statistically significant reduction (p=0.003) was seen in the percentage of proliferating tumor cells as well as in the level of blood vessels within the tumors.

“The findings of this study published in a peer-reviewed journal are the outcome of over two years of research as well as the vast knowledge of PLX cell properties we have developed over the last 10 years. We believe the findings show promise for the utilization of our induced PLX cells in slowing and reversing the growth of cancer cells, particularly for some cancers that don’t have viable treatment options,” stated Zami Aberman, Chairman and Co-CEO of Pluristem. “The findings also confirm the effectiveness of IM administration and support a mechanism of action involving immunomodulation and inhibition of angiogenesis and cell proliferation in cancerous conditions. Our unique patented manufacturing platform allows us to alter our cells’ secretion profile in correlation with the targeted cancer cells, which may open new possibilities in the field of oncology to treat solid tumors and may also offer new paths to help millions of patients around the world. As in immunotherapy technology, PLX cells potentially have the ability to communicate with the body and to secrete biological components that enhance regeneration processes and support the body in fighting cancer cells.”

Pluristem has filed patent applications relating to the technology for the induction of PLX cells and the use of these cells for the treatment of cancer.

Rare Melanoma Type Highly Responsive to Immunotherapy

Desmoplastic melanoma is a rare subtype of melanoma that is commonly found on sun-exposed areas, such as the head and neck, and usually seen in older patients. Treatment is difficult because these tumors are often resistant to chemotherapy and lack actionable mutations commonly found in other types of melanoma that are targeted by specific drugs. However, Moffitt Cancer Center researchers report in the Jan. 10 issue of Nature that patients with desmoplastic melanoma are more responsive to immune-activating antiPD-1/PD-L1 therapies than previously assumed.

Drugs that reactivate a patient’s own immune system to target cancer cells are rapidly changing the face of cancer therapy. Pembrolizumab and nivolumab have been approved to treat melanoma, and others are in development. These drugs block the interaction between the proteins PD-1 and PD-L1. During cancer development, PD-1 and PD-L1 inhibit the immune system and allow tumor cells to escape detection and continue to grow. By blocking their interaction, immune-activating drugs restimulate the immune system to detect and destroy cancer cells.

Scientists previously believed that the tissue architecture of desmoplastic melanomas would reduce the ability of immune cells to infiltrate the tumor area and limit the effectiveness of immune-activating drugs. However, based on anecdotal reports of favorable responses, a group of researchers including Moffitt’s Zeynep Eroglu, M.D., Jane Messina, M.D., and Dae Won Kim, M.D., hypothesized that patients with desmoplastic melanoma may be more responsive to antiPD-1/PD-L1 therapies than previously assumed, and explored this in the largest group of immunotherapy-treated desmoplastic melanoma patients studied to date.

To test their hypothesis, the researchers analyzed 60 patients with advanced/metastatic desmoplastic melanoma who were previously treated with a drug that targets either PD-1 or PD-L1. They discovered that 42 patients had a significant response to treatment.  Approximately half of these patients had a complete response in which their tumors entirely disappeared, and the remainder had a partial response, with significant reduction of their tumors.  Seventy-four percent of patients were still alive more than two years after beginning treatment. This 70 percent response rate is one of the highest reported for antiPD-1/PD-L1 therapies to date, and is even higher than response rates commonly observed in patients with other subtypes of melanoma, which are approximately 35 to 40 percent.

In a collaborative effort involving 10 United States and international cancer centers including Moffitt and University of California Los Angeles, researchers wanted to determine the biological reasons why patients with desmoplastic melanoma may benefit from drugs that target PD-1 or PD-L1. They first confirmed that desmoplastic melanomas have high levels of DNA mutations, as they are highly associated with ultraviolet light DNA damage caused by sun exposure. NF-1 mutations were found as the most common driving genetic event.  They also demonstrated that desmoplastic melanomas have the pre-existing immune cells and proteins necessary to mount an immune response against cancer cells. They compared tissue biopsies from patients with desmoplastic melanoma and non-desmoplastic melanoma. They discovered that desmoplastic melanomas have more cells with high levels of the PD-L1 protein within both the tumor and the invading edges of the tumor. Desmoplastic melanomas also have high levels of immune cells called CD8 T cells that are critical for immune-activating drugs to be effective.

“Our findings challenge the previous school of thought that immunotherapy would offer little benefit to patients with desmoplastic melanoma due to the dense tissue architecture of these tumors. These tumors in fact have the necessary biological ingredients to be very effective targets for anti-PD-1 drugs,” said Eroglu, assistant member of the Cutaneous Oncology Department at Moffitt. “Often, combinations of two immunotherapy drugs are used to treat patients with melanoma to try to improve tumor response rates and survival above current reported rates.  However, these combinations can lead to significantly higher rate of severe side-effects than treatment with anti-PD-1 therapy alone.  Our data suggest that single-agent anti-PD-1 therapy may well be sufficient for patients with desmoplastic melanoma, potentially sparing them the increased toxicities generally observed with combinations of immunotherapies.”

New Polygenic Hazard Score Predicts When Men Develop Prostate Cancer

An international team, led by researchers at the University of California San Diego School of Medicine, has developed and validated a genetic tool for predicting age of onset of aggressive prostate cancer, a disease that kills more than 26,000 American men annually.

The tool, described in the January 11 online issue of the BMJ (formerly the British Medical Journal), may potentially be used to help guide decisions about who to screen for prostate cancer and at what age.

Currently, detection of prostate cancer relies primarily upon the prostate-specific antigen (PSA) screening blood test. But PSA testing is not very good as a screening tool. While it reduces deaths from prostate cancer, indiscriminate PSA screening also produces false positive results and encourages over-detection of non-aggressive, slow-growing tumors.

“The existing PSA test is useful, but it is not precise enough to be used indiscriminately on all men,” said the study’s first author, Tyler M. Seibert, MD, PhD, chief resident physician in the Department of Radiation Medicine and Applied Sciences at UC San Diego School of Medicine. “As a result, it may prompt medical interventions like biopsy, surgery or radiotherapy that might not be necessary.”

Seibert, senior author Anders Dale, PhD, professor and co-director of the Center for Translational Imaging and Precision Medicine at UC San Diego School of Medicine, and colleagues in Europe, Australia and the United States, used genome-wide association studies (GWAS) to determine whether a man’s genetic predisposition to developing prostate cancer could be used to predict his risk of developing the aggressive and lethal form of the disease.

GWAS search individual genomes for small variations, called single-nucleotide polymorphisms (SNPs), that occur more frequently in people with a particular disease than in people without the disease. Hundreds or thousands of SNPs can be evaluated at the same time in large groups of people. In this case, researchers used data from over 200,000 SNPs from 31,747 men of European ancestry participating in the ongoing international PRACTICAL consortium project.

Using a method developed at UC San Diego, the researchers combined information from GWAS and epidemiological surveys to assess quantification for genetic risk at age of disease onset. “Polygenic Hazard Score methodology is specialized in finding age-dependent genetic risks and has already been proven to be very useful in predicting age of onset for Alzheimer’s disease”, said study co-author Chun Chieh Fan, MD, PhD, in the Department of Cognitive Science at UC San Diego.

“The polygenic hazard score is very versatile and can be applied to many age-related diseases,” said Fan. “In this case, the polygenic hazard score of prostate cancer captures the age variations of aggressive prostate cancer.”

Genotype, prostate cancer status and age were analyzed to select SNPs associated with prostate cancer diagnosis. Then the data was incorporated into the polygenic hazard score, which involves survival analysis to estimate SNPs’ effects on age at diagnosis of aggressive prostate cancer. The results led to a polygenic hazard score for prostate cancer that can estimate individual genetic risk. This score was then tested against an independent dataset, from the recent UK ProtecT trial, for validation.

“The polygenic hazard score was calculated from 54 SNPs and proved to be a highly significant predictor of age at diagnosis of aggressive prostate cancer,” said Seibert. “When men in the ProtecT dataset with a high polygenic hazard score were compared to those with average PHS, their risk of aggressive prostate cancer was at least 2.9 times greater.”

“And when we account statistically for the effect of the GWAS having disproportionately high numbers of men with disease compared to the general population, we estimate that the risk defined by the polygenic hazard score is 4.6 times greater.”

The study authors note that an individual’s genotype does not change with age, so the polygenic hazard score can be calculated at any time and used as a tool for men deciding whether and when to undergo screening for prostate cancer. This is especially critical for men at risk of developing prostate cancer at a very young age, before standard guidelines recommend consideration of screening.

“This kind of genetic risk stratification is a step toward individualized medicine,” said Dale, who also noted that PSA tests are much more predictive of aggressive prostate cancer in men with high polygenic hazard score than in those with low polygenic hazard score. This suggests that polygenic hazard score can help physicians determine whether to order a PSA test for a given patient, in the context of the patient’s general health and other risk factors.

Investigators caution that further study of the clinical benefits are needed before the polygenic hazard score is ready for routine use.

Texas A&M Research Shows Biological Clocks Could Improve Brain Cancer Treatment

Biological clocks throughout the body play a major role in human health and performance, from sleep and energy use to how food is metabolized and even stroke severity. Now, Texas A&M University researchers found that circadian rhythms could hold the key to novel therapies for glioblastoma, the most prevalent type of brain cancer in adults—and one with a grim prognosis.

Scientists in the Texas A&M Center for Biological Clocks Research (CBCR) determined that the timed production of a particular protein, associated with tumor proliferation and growth, is disrupted in glioblastoma cells, and they believe that this may lead to a more effective technique to treat the cancerous cells without damaging the healthy surrounding tissue. These findings, which were supported in part by the National Institutes of Health, were published today (Jan. 10) in the international journal BMC Cancer.

Texas A&M biologist Deborah Bell-Pedersen, PhD, a co-corresponding author on the study, found in her previous research that the biological clock in the model fungal system Neurospora crassa controls daily rhythms in the activity of a signaling molecule, called p38 mitogen activated protein kinase (MAPK). This signaling protein plays a role in glioblastoma’s highly invasive and aggressive properties.

In the new research, David J. Earnest, PhD, a mammalian biological clocks expert at the Texas A&M College of Medicine and co-corresponding author on the study, collaborated with Bell-Pedersen to show that the clock controls daily rhythms in p38 MAPK activity in a variety of mammalian cells as well, including normal glial cells, the supporting “helper” cells surrounding neurons.

Furthermore, their work found that such regulation is absent in glioblastoma cells. “We tested to see if inhibition of this cancer-promoting protein in glioblastoma cells would alter their invasive properties,” said Bell-Pedersen, an internationally recognized leader in the fields of circadian and fungal biology. “Indeed, we found that inhibition of p38 MAPK at specific times of the day—times when the activity is low in normal glial cells under control of the circadian clock—significantly reduced glioblastoma cell invasiveness to the level of noninvasive glioma cells.”

These findings indicate that glioblastoma might be a good candidate for chronochemotherapy, meaning treating cancer at specific times of day to get the most impact.

“Chronotherapeutic strategies have had a significant positive impact on the treatment of many types of cancer by optimizing the specific timing of drug administration to improve the efficacy and reduce the toxicity of chemotherapy,” Bell-Pedersen said. “However, circadian biology has not been applied to the development of chronotherapeutic strategies for the treatment of glioblastoma, and clinical outcomes for this common primary brain tumor have shown limited improvement over the past 30 years.”

Glioblastomas gained some attention this summer when Senator John McCain was diagnosed with the condition. “A big reason for poor prognosis for patients with this aggressive type of tumor is that the glioblastoma cells rapidly and unabatedly invade and disrupt the surrounding brain cells,” said Gerard Toussaint, MD, a clinician and assistant professor at the Texas A&M College of Medicine who specializes in glioblastoma. Current treatments—including chemotherapy, surgical resection, immunotherapy and radiation—are largely ineffective in prolonging life expectancy beyond 18 months.

“We found that an inhibitor of p38 MAPK activity would make the cells behave less invasively, and if you can control the invasive properties, you can improve prognosis,” Earnest said. In addition, the team’s data indicate such treatment may be more effective and less toxic if administered at the appropriate time of the day.

This reduced toxicity is important, because a drug to inhibit the cancer-promoting activity of this protein was tested but found to be too harmful, with too many side effects. “If treatment with the drug can be timed to when the normal glial cells naturally have low activity of p38 MAPK, the addition of the drug might not be as toxic for these cells, and yet would still be very effective on the cancerous cells,” Earnest said.

Although promising, the current studies were done using cell cultures. The team’s next step is to test p38 inhibitor chronochemotherapy in an animal model for glioblastoma. If successful, they would then move on to clinical trials.

“We work on a model system, and the reason to do that is that we can make progress quickly, and we always hope that what we’re working on will lead to something useful, and I think this is a prime example of how putting effort into basic research can pay off,” Bell-Pedersen said. “We’re very hopeful and encouraged by our data that we’ll find a treatment.”

‘Decorated’ Stem Cells Could Offer Targeted Heart Repair

Although cardiac stem cell therapy is a promising treatment for heart attack patients, directing the cells to the site of an injury – and getting them to stay there – remains challenging. In a new pilot study using an animal model, North Carolina State University researcher Ke Cheng and his team show that “decorating” cardiac stem cells with platelet nanovesicles can increase the stem cells’ ability to find and remain at the site of heart attack injury and enhance their effectiveness in treatment.

“Platelets can home in on an injury site and stay there, and even in some cases recruit a body’s own naturally occurring stem cells to the site, but they are a double-edged sword,” says Cheng, associate professor of veterinary medicine and associate professor in the NC State/UNC Joint Department of Biomedical Engineering. “That’s because once the platelets arrive at the site of injury, they trigger the coagulation processes that cause clotting. In a heart-attack injury, blood clots are the last thing that you want.”

Cheng and his associates wondered if it would be possible to co-opt a platelet’s ability to locate and stick to an injury site without inducing clotting. They found that adhesion molecules (a group of glycoproteins) located on the platelet’s surface were responsible for its ability to find and bind to an injury. So the team created platelet nanovesicles from these molecules, and then decorated the surface of cardiac stem cells with the nanovesicles,

“The nanovesicle is like the platelet’s coat,” Cheng says. “There isn’t any internal cellular machinery that could activate clotting. When you place the nanovesicle on the stem cell, it’s like giving the stem cell a tiny GPS that helps it locate the injury so it can do its repair work without any of the side effects associated with live platelets.”

In a proof-of-concept study involving a rat model of myocardial infarction, twice as many platelet nanovesicle decorated cardiac stem cells, or PNV-CSCs, were retained in the heart than non-decorated cardiac stem cells. The rodents were monitored for four weeks. Overall, the rats in the PNV-CSC group showed nearly 20 percent or higher cardiac function than the control CSC group.

A small pilot study in a pig model also demonstrated higher rates of stem cell retention with PNV-CSCs, though the team did not perform functional studies. A future follow-up study is planned.

“Platelet nanovesicles do not affect the performance of the cardiac stem cells, and are free from any negative side effects,” Cheng says. “Hopefully we will be able to use this approach to improve cardiac stem cell therapy in clinical trials in the future.”

Researchers Seek Blood Test for Early Lung Cancer Detection

Researchers at Rush University Medical Center are trying to answer that question by working to develop a blood test for early detection of lung cancer. National Institutes of Health awarded this endeavor a two-year $275,000 grant on Jan. 1.

The availability of a simple and cost-effective blood test could change early detection of lung cancer, which is often undiagnosed until symptoms become apparent in a more serious, advanced stage of the disease.

“Our goal is to improve the way lung cancer is diagnosed using a simple blood test to detect the disease earlier and reduce the number of late-stage diagnoses,” said biochemist Jeffrey A. Borgia, PhD. “We are aiming to identify those who are at a higher risk by looking for a specific ‘signature’ of cancer-specific molecules (or biomarkers) in the blood.

“Currently there are screening guidelines for those who are at risk — people who have a history of smoking and are 55 to 80 years old — but what about a nonsmoking young person who gets lung cancer?”

According to the American Cancer Society, as many as 20 percent of the people who die from lung cancer in the United States every year have never smoked or used any other form of tobacco. This translates to about 30,000 Americans in 2017.

Blood test would improve on and complement CT screenings

Currently, people at risk for lung cancer are advised to receive a low-dose computed tomography (CT) scan of their lungs to detect early-stage cancers.

“It is an effective screening tool, but most of the nodules we identify with CT scanning will turn out to be benign,” said Dr. Christopher Seder, a thoracic surgeon at Rush. “We are trying to develop a better way to determine whether the nodule is malignant or not.”

Also, while low-dose CT scanning currently is the best method for catching lung cancer early, the established guidelines for screening exclude many people who may still be diagnosed with the disease.

“The blood test ideally could be used as a detection method that will complement current CT imaging technology,” Borgia said.

Biomarkers are key to cancer test

Cancer cells release a series of proteins and other biomolecules into the bloodstream that are unique to the type of cancer, known as biomarkers.

Using one of the world’s largest institutional repositories of blood and tissue samples from patients with benign and malignant thoracic tumors at Rush, Borgia’s team has identified several biomarkers in the blood that may be able to identify non-small cell lung cancer with about 90 percent accuracy.

Thanks to the cell samples from patients — about 10 percent of whom fall outside current CT screening criteria — the team also is searching for biomarkers that could lead to a “prescreening” blood test designed to detect additional populations that might benefit from CT screening but do not meet current criteria, outlined above.

Rush University Medical Center has been on the leading edge of the lung cancer CT screening and lung cancer treatment. Rush is an American College of Radiology-designated screening center as well as a Lung Cancer Alliance Screening Center of Excellence.

Rush’s preventive low-dose screening program, created in 2015, resulted in more than 3 percent cancer diagnoses found at earlier stages than when lung cancers are typically found. For these early-stage cancers, Dr. Michael Liptay and his thoracic surgical colleagues at Rush were able to perform minimally invasive procedures that gave these patients a better chance at survival.

Beta Blockers May Boost Immunotherapy, Help Melanoma Patients Live Longer

A common, inexpensive drug that is used to prevent heart attacks and lower blood pressure may also help melanoma patients live longer.

Researchers at Penn State found that melanoma patients who received immunotherapy while taking a specific type of beta blocker lived longer than patients who received immunotherapy alone. In a follow-up experiment with mice, the researchers saw the same results.

Todd Schell, professor of microbiology and immunology at Penn State College of Medicine, said that because beta blockers are already widely available, the findings – published in the journal OncoImmunology – could indicate a simple way for physicians to better treat their patients.

“The type of beta blocker we found to be effective against melanoma – pan beta blockers – was actually the least prescribed,” Schell said. “Most patients are either prescribed beta 1 selective blockers or are not taking beta blockers at all. This means there’s a large population of patients who may be eligible to take pan beta blockers while being treated with immunotherapy. And because beta blockers are already FDA approved, it’s something we know is safe and can be very quickly implemented in patient care.”

Patients with metastatic melanoma, or melanoma that has spread to other parts of the body, often have a poor prognosis, and while some forms of immunotherapy – treatments that boost the body’s immune system to fight disease – are promising, response rates are less than 35 percent.

Previous research has shown that physiological stress prevents the immune system from fighting tumors effectively, while lower stress boosts the benefits of anti-cancer treatments. The researchers were curious about whether lowering stress with beta blockers would improve outcomes in patients treated with immunotherapies.

“Beta blockers slow your heart rhythm, but they can also affect immune cells and improve immune function,” Schell said. “We wanted to see if there would be a correlation between the beta blockers patients were taking for another condition and their response to immunotherapy. For metastatic melanoma, there are currently three different types of immunotherapy approved for use, and we specifically looked at that population of people.”

In studies developed by Dr. Kathleen Kokolus, a postdoctoral fellow, the researchers analyzed data from 195 metastatic melanoma patients who were treated with immunotherapy between 2000 and 2015, 62 of which were also taking beta blockers. They compared survival between the patients taking beta one-selective blockers, pan beta blockers and no beta blockers.

While there was little difference in how long patients taking beta one-selective blockers or no beta blockers lived, the results indicate that patients taking pan beta blockers lived significantly longer than the others. Five years after immunotherapy, about 70 percent of patients receiving pan beta blockers were still alive, versus about 25 percent of those taking beta one-selective blockers or no beta blockers at all.

To help explain the results, the team performed a parallel experiment in mice with melanoma. They treated the mice with immunotherapy and with or without the pan beta blocker propranolol. The researchers found that the propranolol significantly delayed tumor growth and increased survival when combined with immunotherapy.

Dr. Joseph Drabick, professor of medicine, said the results suggest that reducing physiological stress with beta blockers can help improve the effectiveness of immunotherapy and survival for melanoma patients.

“These new immunotherapies are great, but they don’t work for everyone,” Drabick said. “So how can we make these treatments better? We saw that for patients taking pan beta blockers, there was a dramatic improvement in survival, and we were able to duplicate these findings in mice and see the exact same phenomenon.”

Drabick also said the study was a good example of the benefits of finding new uses for drugs that have been around awhile.

“The benefit of this is that beta blockers already have a long history of safety in people, and they’re cheap and generic,” Drabick said. “And now they have the potential to augment some of these newer immunotherapy drugs to help people with cancer.”

Schell said that in the future, they’ll be working on a clinical trial to further explore and understand the role of beta blockers in treating cancer.

BriaCell Provides Clinical Update on its Lead Immunotherapy Drug in Advanced Breast Cancer

BriaCell, an immuno-oncology focused biotechnology company with a proprietary targeted immunotherapy technology, has provided a clinical update regarding its ongoing clinical trials of Bria-IMT™ (formerly referred to as SV-BR-1-GM).

BriaCell currently is enrolling patients in two separate but related clinical trials. Trial WRI-GEV-007 (listed in ClinicalTrials.gov as NCT03066947) is a Phase I/IIa clinical study designed to evaluate the safety and efficacy of Bria-IMT™ in metastatic or locally recurrent breast cancer patients.  In this study, Bria-IMT™ is given in a regimen including low-dose pre-dose cyclophosphamide (to reduce suppression of the immune response) and post-dose interferon-alpha (to boost the immune response).  The second clinical trial, BRI-ROL-001 (listed in ClinicalTrials.gov as NCT03328026), is a rollover study of Bria-IMT™ in combination with Keytruda® [pembrolizumab] or Yervoy® [ipilimumab].

Patient recruitment is on schedule despite interruption due to temporary shutdown of some clinical sites, affected by wildfires and hurricanes. Seven patients have enrolled in the WRI-GEV-007 clinical trial with 6 treated to date (1 patient dropped out after cyclophosphamide pre-treatment and did not receive Bria-IMT™). Based on results to-date, Bria-IMT™ has been very well tolerated and the majority of adverse events were limited to expected minor local irritation at the injection sites.  No serious adverse events related to Bria-IMT™ have been reported and no new or unexpected safety issues related to Bria-IMT™ have been observed.  The Phase I portion of the study has been successfully completed, and the Phase IIa portion is currently enrolling.

One patient is worth discussing in detail. This 73-year-old woman had breast cancer diagnosed in 1995.  She developed liver metastases in 2010, and then lung metastases in 2017. Prior treatments included surgery, radiation therapy, hormonal therapy and seven rounds of chemotherapy with 8 different chemotherapy agents. She received 5 cycles of Bria-IMT™ over the first 3 months of treatment, then 3 additional cycles over the following 3 months (6 months total).  Evaluation was performed after 3 months and 6 months. After 3 months, despite the extensive prior therapy, her scans noted that, “there has been a clear response in the multiple bilateral pulmonary nodules” indicating that several lung tumors had disappeared or decreased in size.  This response was maintained after 6 months of treatment with Bria-IMT™.  The liver tumors were stable to slightly increased at 3 months, and then progressed after 6 months.

Like the patient reported previously by Dr. Wiseman, BriaCell’s Scientific Founder, in a proof-of-concept clinical study, this patient is a double match with Bria-IMT™ at two specific biomarkers (HLA-A and HLA-DRB3).  This is highly significant, as it supports our BriaDX™ hypothesis that these biomarkers can be used to select the patients most likely to respond to Bria-IMT™ therapy.  We also noted in this patient that, while circulating tumor-associated cells decreased following the initial treatment, the expression of PD-L1, a molecule that suppresses the immune response, increased during treatment. This suggests that treating this patient (and other similar patients) with Bria-IMT™ in combination with a potent PD-1 inhibitor such as Keytruda® [pembrolizumab] may be a highly effective method to improve the efficacy of the treatment and patient outcomes.

A third clinical site was recently added to the study and several patients are being evaluated for the WRI-GEV-007 study. Discussions are ongoing with two additional clinical sites which are expected to be added in the near future. The combination rollover study, BRI-ROL-001, is available to enroll patients.

Other activities remain on track.  The companion diagnostic, BriaDX™, has been bolstered by the important supporting data for the HLA biomarker matching hypothesis noted above.  BriaCell is also developing an off-the-shelf, personalized immunotherapy (Bria-OTS™) to treat a much wider patient population (with ~90% of the population being a double-match with Bria-OTS™).  In collaboration with University of Zurich, Switzerland, BriaCell is testing other drugs/product candidates that are expected to boost the effectiveness of Bria-IMT™ and Bria-OTS™.

Ongoing work in the small molecule program to select protein kinase C delta inhibitors for cancer and fibrotic diseases is also progressing according to our timelines. The medicinal chemistry work is being performed at Colorado State University where the current library of compounds available is being augmented.

BriaCell is an immuno-oncology focused biotechnology company developing a targeted and safe approach to the management of cancer. Immunotherapy has come to the forefront of the fight against cancer, harnessing the body’s own immune system in recognizing and selectively destroying cancer cells while sparing normal ones. Immunotherapy, in addition to generally being more targeted and less toxic than commonly used types of chemotherapy, is also thought to be a potent approach with the potential to prevent cancer recurrence.

Bria-IMT™ (SV-BR-1-GM), the Company’s lead product candidate, is derived from a breast cancer cell line genetically engineered to release granulocyte-macrophage colony-stimulating factor (GM-CSF), a substance that activates the immune system by allowing the body to recognize and eliminate cancerous cells by inducing tumor-directed T cell and potentially antibody responses.

The results of two previous proof-of-concept clinical trials (one with the precursor cell line not genetically engineered to produce GM-CSF and one with Bria-IMT™) produced encouraging results in patients with advanced breast cancer. Most notably, one patient with metastatic breast cancer responded to Bria-IMT™ with substantial reduction in tumor burden including breast, lung, soft tissue and brain metastases. The company is currently conducting a Phase I/IIa clinical trial for Bria-IMT™ in patients with advanced breast cancer.  This trial is listed in ClinicalTrials.gov as NCT03066947.  The trial is being conducted along with the co-development of BriaDX™, the Company’s companion diagnostic test. The interim data for the first 10 patients is expected by the first quarter of 2018. Additionally, the FDA recently approved the roll-over combination study of Bria-IMT™ with pembrolizumab [Keytruda; manufactured by Merck & Co., Inc.] or ipilimumab [Yervoy; manufactured by Bristol-Myers Squibb Company] for patients previously treated with Bria-IMT™ in the Company’s ongoing Phase I/IIa clinical trial in advanced breast cancer. The roll-over trial is listed in ClinicalTrials.gov as NCT03328026.

BriaCell is also developing Bria-OTS™, an off-the-shelf personalized Immunotherapy.  Bria-OTS™ consists of 14 individually pre-manufactured genetic alleles. BriaCell’s BriaDX™ companion diagnostic reveals a patient’s specific HLA-types and the 2 best matching alleles are administered to the patient. BriaCell’s 14 alleles (8 Class I and 6 Class II) cover approximately 90% of the Breast Cancer population while eliminating the complex manufacturing logistics required for other personalized immunotherapies. Bria-OTS™ is a personalized therapy without the need for personalized manufacturing.

BriaCell is also developing novel, selective protein kinase C delta (PKCδ) inhibitors. PKCδ inhibitors have shown activity in a number of pre-clinical models of RAS genes’ transformed cancers including breast, pancreatic, non-small cell lung cancer and neuroendocrine tumors (such as carcinoid tumors).

For additional information on BriaCell, please visit our website: http://briacell.com.

Researchers Detect a Loophole in Chronic Lymphocytic Leukemia Treatment

A team of researchers in Italy and Austria has determined that a drug approved to treat chronic lymphocytic leukemia (CLL) may be less effective in a particular subset of patients. The study, which will be published January 4 in the Journal of Experimental Medicine, reveals that ibrutinib has a diminished capacity to delocalize and kill tumor cells expressing an adhesive protein called CD49d, but combining ibrutinib treatment with drugs that block CD49d activation could prevent the tumor cells from sheltering in lymphoid organs.

CLL is the most common leukemia in adults, and it is characterized by the presence of cancerous B cells that accumulate in the lymph nodes, spleen, and liver. Ibrutinib reallocates CLL cells from lymph nodes into the blood by inhibiting Bruton’s tyrosine kinase (BTK), a key enzyme in the B cell receptor (BCR) signaling pathway.

BCR signaling promotes the survival and differentiation of normal, healthy B cells in several ways, including by activating the adhesion receptor VLA-4, which attaches B cells to other, supportive cells within lymph nodes. One of the subunits of VLA-4, CD49d, is highly expressed in about 40% of CLL patients. These patients tend to have poorer outcomes than patients that do not express CD49d, but the role of VLA-4 in CLL is unclear.

A team of researchers led by Antonella Zucchetto and Valter Gattei of the CRO Aviano National Cancer Institute in Italy and Tanja Nicole Hartmann of the Paracelsus Medical University in Salzburg, Austria, found that BCR signaling can activate VLA-4 in CD49d-expressing CLL cells, thereby enhancing the cells’ adhesiveness. Even though ibrutinib treatment impaired BCR signaling in these cells, it was unable to fully hinder the pathway from activating VLA-4 and enhancing cell adhesion.

The researchers analyzed three different cohorts of CLL patients from Italy and the United States. In all three groups, patients expressing higher levels of CD49d showed reduced responses to ibrutinib treatment: the drug appeared to be less able to displace tumor cells from lymph nodes into the blood, resulting in decreased lymph node shrinkage and shorter progression-free survival times.

“Our results suggest that VLA-4–expressing CLL cells residing in the secondary lymphoid organs can receive BCR-mediated stimuli that can activate VLA-4 even in the presence of ibrutinib,” says Zucchetto. “This activation leads to enhanced retention of VLA-4–positive CLL cells in tissue sites, thereby affecting patient outcome.”

In addition to the ibrutinib target BTK, BCR signaling can proceed through an alternative enzyme called phosphatidylinositide 3-kinase. The researchers found that simultaneously inhibiting both BTK and phosphatidylinositide 3-kinase completely blocked VLA-4 activation in CLL cells.

“Our data suggest that evaluation of CD49d expression in patients initiating ibrutinib therapy may identify those cases that would benefit from combination therapy approaches designed to completely block VLA-4 activation and VLA-4–mediated retention of leukemic cells in protective tissue compartments,” says Gattei.

Immune Cells Play Key Role in Early Breast Cancer Metastasis Even Before a Tumor Develops

Mount Sinai researchers have discovered that normal immune cells called macrophages, which reside in healthy breast tissue surrounding milk ducts, play a major role in helping early breast cancer cells leave the breast for other parts of the body, potentially creating metastasis before a tumor has even developed, according to a study published in Nature Communications.

The macrophages play a role in mammary gland development by regulating how milk ducts branch out through breast tissue. Many studies have also proven the importance of macrophages in metastasis, but until now, only in models of advanced large tumors. By studying human samples, mouse tissues, and breast organoids, which are miniaturized and simplified versions of breast tissue produced in the lab, the new research found that in very early cancer lesions, macrophages are attracted to enter the breast ducts where they trigger a chain reaction that brings early cancer cells out of the breast, said lead researcher Julio Aguirre-Ghiso, PhD, Professor of Oncological Sciences, Otolaryngology, Medicine, Hematology and Medical Oncology at The Tisch Cancer Institute at the Icahn School of Medicine at Mount Sinai.

This research shows that macrophages’ relationship with normal breast cells is co-opted by early cancer cells that activate the cancer-causing HER2 gene, helping in this newly-discovered role of these immune cells. The findings from this study could eventually help pinpoint biomarkers to identify cancer patients who may be at risk of carrying potential metastatic cells due to these macrophages and potentially lead to the development of novel therapies that prevent early cancer metastasis.

Early treatment of high-risk patients may prevent the formation of deadly metastasis better than the current standard of treating metastatic disease only once it has occurred, said key researcher Miriam Merad, MD, PhD, Director of the Precision Immunology Institute and the Human Immune Monitoring Center and co-leader of the Cancer Immunology program at The Tisch Cancer Institute at the Icahn School of Medicine at Mount Sinai.

“Our study challenges the dogma that early diagnosis and treatment means sure cure,” Dr. Aguirre-Ghiso said. “In this study and in our previous studies, we present mechanisms governing early dissemination.  This work further sheds light onto the mysterious process of early dissemination and cancer of an unknown primary tumor.”

Researchers hope to build on this study by identifying which macrophages specifically control early dissemination. They also hope to further detail how early disseminated cancer cells interact with macrophages in the lungs where metastases eventually form and how this interaction can be targeted to prevent metastasis.

“Here, we have identified how macrophages and early cancer cells form a ‘microenvironment of early dissemination’ and show that by disrupting this interaction we can prevent early dissemination and ultimately deadly metastasis,” said Dr. Merad. “This sheds light onto the mysterious process of early dissemination and for patients who have metastasis cancer that came from an unknown source.”

NIH Discovery Brings Stem Cell Therapy for Eye Disease Closer to the Clinic

Scientists at the National Eye Institute (NEI), part of the National Institutes of Health, report that tiny tube-like protrusions called primary cilia on cells of the retinal pigment epithelium (RPE)—a layer of cells in the back of the eye—are essential for the survival of the retina’s light-sensing photoreceptors. The discovery has advanced efforts to make stem cell-derived RPE for transplantation into patients with geographic atrophy, otherwise known as dry age-related macular degeneration (AMD), a leading cause of blindness in the U.S.  The study appears in the January 2 Cell Reports.

“We now have a better idea about how to generate and replace RPE cells, which appear to be among the first type of cells to stop working properly in AMD,” said the study’s lead investigator, Kapil Bharti, Ph.D., Stadtman Investigator at the NEI. Bharti is leading the development of patient stem cell-derived RPE for an AMD clinical trial set to launch in 2018.

In a healthy eye, RPE cells nourish and support photoreceptors, the cells that convert light into electrical signals that travel to the brain via the optic nerve. RPE cells form a layer just behind the photoreceptors. In geographic atrophy, RPE cells die, which causes photoreceptors to degenerate, leading to vision loss.

Bharti and his colleagues are hoping to halt and reverse the progression of geographic atrophy by replacing diseased RPE with lab-made RPE. The approach involves using a patient’s blood cells to generate induced-pluripotent stem cells (iPSCs), cells capable of becoming any type of cell in the body. iPSCs are grown in the laboratory and then coaxed into becoming RPE for surgical implantation.

Attempts to create functional RPE implants, however, have hit a recurring obstacle: iPSCs programmed to become RPE cells have a tendency to get developmentally stuck, said Bharti. “The cells frequently fail to mature into functional RPE capable of supporting photoreceptors. In cases where they do mature, however, RPE maturation coincides with the emergence of primary cilia on the iPSC-RPE cells.”

The researchers tested three drugs known to modulate the growth of primary cilia on iPSC-derived RPE. As predicted, the two drugs known to enhance cilia growth significantly improved the structural and functional maturation of the iPSC-derived RPE. One important characteristic of maturity observed was that the RPE cells all oriented properly, correctly forming a single, functional monolayer. The iPSC-derived RPE cell gene expression profile also resembled that of adult RPE cells. And importantly, the cells performed a crucial function of mature RPE cells: they engulfed the tips of photoreceptor outer segments, a pruning process that keeps photoreceptors working properly.

By contrast, iPSC-derived RPE cells exposed to the third drug, an inhibitor of cilia growth, demonstrated severely disrupted structure and functionality.

As further confirmation of their observations, when the researchers genetically knocked down expression of cilia protein IFT88, the iPSC-derived RPE showed severe maturation and functional defects, as confirmed by gene expression analysis. Tissue staining showed that knocking down IFT88 led to reduced iPSC-derived RPE cell density and functional polarity, i.e., cells within the RPE tissue pointed in the wrong direction.

Bharti and his group found similar results in iPSC-derived lung cells, another type of epithelial cell with primary cilia. When iPSC-derived lung cells were exposed to drugs that enhance cilia growth, immunostaining confirmed that the cells looked structurally mature.

The report suggests that primary cilia regulate the suppression of the canonical WNT pathway, a cell signaling pathway involved in embryonic development. Suppression of the WNT pathway during RPE development instructs the cells to stop dividing and to begin differentiating into adult RPE, according to the researchers.

The researchers also generated iPSC-derived RPE from a patient with ciliopathy, a disorder that causes severe vision loss due to photoreceptor degeneration. The patient’s ciliopathy was associated with mutations of cilia gene CEP290. Compared to a healthy donor, iPSC-derived RPE from the ciliopathy patient had cilia that were smaller. The patient’s iPSC-derived RPE also had maturation and functional defects similar to those with IFT88 knockdown.

Further studies in a mouse model of ciliopathy confirmed an important temporal relationship: Looking across several early development stages, the RPE defects preceded the photoreceptor degeneration, which provides additional insights into ciliopathy-induced retinal degeneration.

The study’s findings have been incorporated into the group’s protocol for making clinical-grade iPSC-derived RPE. They will also inform the development of disease models for research of AMD and other degenerative retinal diseases, Bharti said.

This work was supported by the NEI intramural research program and the NIH Common Fund’s Regenerative Medicine Program.

How Defeating THOR Could Bring a Hammer Down on Cancer

It turns out Thor, the Norse god of thunder and the Marvel superhero, has special powers when it comes to cancer too.

Researchers at the University of Michigan Comprehensive Cancer Center uncovered a novel gene they named THOR while investigating previously unexplored regions of the human genome – the dark matter of the human genome.

They characterized a long non-coding RNA (lncRNA) that is expressed in humans, mice and zebrafish. It’s unusual for this type of RNA to be conserved throughout species like this. The team’s thinking was that if the RNA plays a role in other animals and species besides humans, it must be important.

“Genes that are evolutionarily conserved are likely important for biological processes. The fact that we found THOR to be a highly conserved lncRNA was exciting. We chose to focus on it with the thought that it has been selected by evolution for having important functions,” says Arul Chinnaiyan, M.D., Ph.D., director of the Michigan Center for Translational Pathology and S.P. Hicks Professor of Pathology at Michigan Medicine.

In fact, the researchers found this particular lncRNA plays a role in cancer development. And that knocking it out can halt the growth of tumors.

This is the first group to identify and characterize THOR, which stands for Testis-associated Highly-conserved Oncogenic long non-coding RNA. They published their results in Cell.

It’s an early example of how this previously unexplored portion of the genome could lead to a potential new way of attacking cancer.

In 2015, Chinnaiyan’s team published a paper analyzing the global landscape of lncRNAs, which had been considered dark matter because so little was known about it. They identified thousands of potential lncRNAs that might warrant future study.

THOR rose to the top of the list because it was evolutionarily highly conserved. It was also highly expressed, specifically in testes cells. It had little to no expression in other types of adult normal tissue.

Because THOR is highly conserved, researchers were able to study it in mice and zebrafish, as well as in human cells.

“That is one of the challenges of studying lncRNAs that are not conserved. If they’re not conserved in model systems, they are difficult to characterize. Here, because THOR is so highly conserved, we were able to look at its expression and function in zebrafish models,” Chinnaiyan says.

In addition to finding THOR expression in normal testis tissue, the researchers found it was highly expressed in some subsets of cancers, particularly lung cancer and melanoma. As they investigated THOR, they found its expression had a direct impact on cancer development. If they knocked down THOR in cell lines expressing it, tumor growth slowed. If they overexpressed THOR, cells grew faster. And when they eliminated THOR from normal cells, the cells continued to develop normally, suggesting it only impacts cancer cells.

“We’ve gone through a lot of lncRNAs to get to that. Most of the ones we test don’t have a clear function like this,” Chinnaiyan says.

Researchers also found that THOR impacted proteins called IGFBPs, which are thought to be involved in stabilizing RNAs. Knocking down THOR inhibited IGFBP activity.

“If we perturb THOR function, we disturb the ability to stabilize RNA. This inhibits cell proliferation,” Chinnaiyan says. Conversely, when researchers overexpressed THOR, cells grew faster.

Chinnaiyan suggests THOR could be a good target for drug development because blocking it does not impact normal cells. That would likely mean fewer toxic side effects. In future studies, the researchers will look at how to create a compound that binds with THOR in a complimentary sequence designed to knock it down. This approach, known as antisense oligonucleotides, has been used successfully in other contexts.