Tag: immunotherapy

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Zapping Glioblastoma With Electric Fields Slows Tumour Growth

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Source: Pixabay

A new study led by Keck Medicine of USC researchers may have uncovered an effective combination therapy for glioblastoma, a brain tumour diagnosis with few available effective treatments. According to the National Brain Tumor Society, the average survival for patients diagnosed with glioblastoma is eight months.

The study, which was published in the journal Med, finds that using Tumour Treating Fields therapy (TTFields), which delivers targeted waves of electric fields directly into tumours to stop their growth and signal the body’s immune system to attack cancerous tumour cells, may extend survival among patients with glioblastoma, when combined with immunotherapy (pembrolizumab) and chemotherapy (temozolomide).

TTFields disrupt tumour growth using low-intensity, alternating electric fields that push and pull key structures inside tumour cells in continually shifting directions, making it difficult for the cells to multiply. Preventing tumour growth gives patients a better chance of successfully fighting the cancer. When used to treat glioblastoma, TTFields are delivered through a set of mesh electrodes that are strategically positioned on the scalp, generating fields at a precise frequency and intensity focused on the tumour. Patients wear the electrodes for approximately 18 hours a day.

Researchers observed that TTFields attract more tumour-fighting T cells, which are white blood cells that identify and attack cancer cells, into and around the glioblastoma. When followed by immunotherapy, these T cells stay active longer and are replaced by even stronger, more effective tumour-fighting T cells.

“By using TTFields with immunotherapy, we prime the body to mount an attack on the cancer, which enables the immunotherapy to have a meaningful effect in ways that it could not before,” said David Tran, MD, PhD, chief of neuro-oncology with Keck Medicine, co-director of the USC Brain Tumor Center and corresponding author of the study. “Our findings suggest that TTFields may be the key to unlocking the value of immunotherapy in treating glioblastoma.”

TTFields are often combined with chemotherapy in cancer treatment. However, even with aggressive treatment, the prognosis for glioblastoma remains poor. Immunotherapy, while successful in many other cancer types, has also not proved effective for glioblastoma when used on its own.

However, in this study, adding immunotherapy to TTFields and chemotherapy was associated with a 70% increase in overall survival. Notably, patients with larger, unresected (not surgically removed) tumours showed an even stronger immune response to TTFields and lived even longer. This suggests that, when it comes to kick-starting the body’s immune response against the cancer, having a larger tumour may provide more targets for the therapy to work against.

Using alternating electric fields to unlock immunotherapy

Pembrolizumab, the immunotherapy used in this study, is an immune checkpoint inhibitor (ICI), which enhances the body’s natural ability to fight cancers by improving T cells’ ability to identify and attack cancer cells.

However, there are typically few T cells in and around glioblastomas because these tumours originate in the brain and are shielded from the body’s natural immune response by the blood-brain barrier. This barrier safeguards the brain by tightly regulating which cells and substances enter from the bloodstream. Sometimes, this barrier even blocks T cells and other therapies that could help kill brain tumours.

This immunosuppressive environment inside and around the glioblastoma is what makes common cancer therapies like pembrolizumab and chemotherapy significantly less effective in treating it. Tran theorised the best way to get around this issue was to start an immune reaction directly inside the tumour itself, an approach known as in situ immunisation, using TTFields.

This study demonstrates that combining TTFields with immunotherapy triggers a potent immune response within the tumour – one that ICIs can then amplify to bolster the body’s own defence against cancer.

“Think of it like a team sport – immunotherapy sends players in to attack the tumour (the offence), while TTFields weaken the tumour’s ability to fight back (the defence). And just like in team sports, the best defence is a good offence,” said Tran, who is also a member of the USC Norris Comprehensive Cancer Center.

Study methodology and results

The study analysed data from 2-THE-TOP, a Phase 2 clinical trial, which enrolled 31 newly diagnosed glioblastoma patients who had completed chemoradiation therapy. Of those, 26 received TTFields combined with both chemotherapy and immunotherapy. Seven of these 26 patients had inoperable tumours due to their locations – an especially high-risk subgroup with the worst prognosis and few treatment options.

Patients in the trial were given six to 12 monthly treatments of chemotherapy alongside TTFields for up to 24 months. The number and duration of treatments were determined by patients’ response to treatment. The immunotherapy was given every three weeks, starting with the second dose of chemotherapy, for up to 24 months.

Patients who used the device alongside chemotherapy and immunotherapy lived approximately 10 months longer than patients who had used the device with chemotherapy alone in the past. Moreover, those with large, inoperable tumours lived approximately 13 months longer and showed much stronger immune activation compared to patients who underwent surgical removal of their tumours.

“Further studies are needed to determine the optimal role of surgery in this setting, but these findings may offer hope, particularly for glioblastoma patients who do not have surgery as an option,” said Tran.

The researchers are now moving ahead to a Phase 3 trial.

Source: University of Southern California – Health Sciences

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Immune System the Focus of PhD’s Research at UKZN

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Elated at graduating with a doctoral degree is Dr Aviwe Ntsethe. Credit: University of KwaZulu-Natal

Dr Aviwe Ntsethe’s curiosity in the Medical field deepened when he started exploring the complexities of human physiology and the crucial role of the immune system in cancer, leading to him graduating with a PhD.

Growing up in the small town of Bizana in the Eastern Cape, Ntsethe attended Ntabezulu High School, where his passion for Medical Science took root. Despite facing significant challenges, including limited funding opportunities for his studies, he remained determined to advance in the discipline.

Throughout his PhD journey at UKZN, Ntsethe had to juggle multiple jobs to support himself and his studies while conducting his research. He worked at Netcare Education and the KwaZulu-Natal College of Emergency Care, and later took up a position as a contractual laboratory technician in the Department of Physiology at UKZN. It was with the guidance of his PhD supervisor, Professor Bongani Nkambule, that he learned critical work ethics and advanced laboratory techniques. The co-supervision of Professor Phiwayinkosi Dludla further enriched his research experience and contributed to his academic growth.

Ntsethe’s thesis focused on investigating B cell function and immune checkpoint expression in patients with Chronic Lymphocytic Leukaemia (CLL). The study found that patients with CLL had higher levels of immune checkpoint proteins in their B cell subsets, which play a crucial role in regulating the immune system.

Furthermore, using monoclonal antibodies that target these immune checkpoints, he found these patients could potentially benefit from immunotherapy. Specifically, immunotherapy may improve the function of B cells, key players in fighting infections and cancers, thereby offering new hope for better outcomes in patients with CLL.

He has published three papers from this study. ‘I am excited and proud when I reflect on my achievement of completing this significant journey which was both challenging and rewarding, pushing me to expand my knowledge and skills in ways I never imagined.’

Now, a lecturer at Nelson Mandela University, Ntsethe is committed to mentoring the next generation of Medical scientists. He continues to use the invaluable knowledge and experience he gained during his PhD studies to inspire students and cultivate their passions in research and health sciences. Looking ahead, Ntsethe hopes to expand his research, focusing on immune system interactions in chronic diseases while also encouraging students from diverse backgrounds to pursue careers in Medical Science.

Outside academia, Ntsethe enjoys travelling, staying physically active through workouts, playing chess and indulging in coding or programming.

Source: University of KwaZulu-Natal

Categories : Cancer NeurologyTags :

CAR-T Cell Therapy Causes ‘Brain Fog,’ Study Shows

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Killer T cells about to destroy a cancer cell. Credit: NIH

After treatment with CAR-T cells, immune cells engineered to attack cancer, patients sometimes tell their doctors they feel like they have “brain fog,” or forgetfulness and difficulty concentrating.

A new Stanford Medicine-led study shows that CAR-T cell therapy causes mild cognitive impairments, independent of other cancer treatments, and that this happens via the same cellular mechanism as cognitive impairment from two other causes: chemotherapy and respiratory infections such as flu and COVID-19. The study, conducted mostly in mice, which was published in Cell, also identifies strategies for reversing the problem.

Medications that ameliorate brain fog will enable better recovery from cancer immunotherapies, the researchers said.

“CAR-T cell therapy is enormously promising,” said senior author, Michelle Monje, MD, PhD, professor in paediatric neuro-oncology. “We need to understand all its possible long-term effects, including this newly recognised syndrome of immunotherapy-related cognitive impairment, so we can develop therapeutic approaches to fix it.”

The study’s lead authors are Anna Geraghty, PhD, senior staff scientist in the Monje lab, and MD/PhD student Lehi Acosta-Alvarez.

Cognitive impairment after CAR-T cell therapy is typically mild; patients are not developing dementia, for instance. But it is frustrating and may not resolve on its own, Monje said. In mice, her team reversed the impairment using compounds similar to existing medications or medications in clinical development – meaning a treatment could be available relatively quickly, she said.

“We’re deeply interested in how cancer therapies affect cognition because it affects patients’ quality of life,” Monje said. “And this is especially important for kids because their brains are still developing.”

Investigating brain fog

CAR-T cell therapy was approved in the US for acute lymphoblastic leukaemia in 2017. The treatment involves removing some of the patient’s own immune cells, known as T cells, and engineering them to attack targets on cancer cells. The modified T cells are returned to the patient’s body, where they recognise and destroy cancer.

In addition to leukaemia, CAR-T cells are now used to treat other blood cancers, including multiple myeloma and some kinds of lymphoma, and they are being tested in clinical trials for various solid tumours. Monje and her colleagues have an ongoing trial of CAR-T cells for deadly brain stem and spinal cord tumours in children, which is beginning to show success.

Although patients report brain fog after CAR-T cell therapy, studies to measure how much cognitive impairment the therapy causes are only just emerging.

The research team wanted to get a comprehensive understanding of the situations in which CAR-T cell therapy might cause cognitive impairment. They studied mice that had tumours induced in the brain, blood, skin and bone. The researchers wanted to understand the influence on cognition of CAR-T cell treatment in combination with the tumours’ location (originating in, spreading to or staying outside the brain), as well as the degree to which the engineered cells evoked additional, accompanying immune responses. Before and after CAR-T cell treatment, the researchers used standard cognitive tests on the mice, measuring how mice responded to a novel object and navigated a simple maze.

CAR-T therapy caused mild cognitive impairment in mice with cancers originating in, metastasizing to and located completely outside the brain. The only mice tested that did not develop cognitive impairment after CAR-T treatment were those that had bone cancer that causes minimal additional inflammation beyond the cancer-fighting activity of the CAR-T cells.

“This is the first study to demonstrate that immunotherapy on its own is sufficient to cause lasting cognitive symptoms,” Monje said. “It’s also the first paper to uncover the mechanisms. We found the exact same pathophysiology we’ve seen in brain fog syndromes that occur after chemotherapy, radiation, and mild respiratory COVID-19 or influenza.”

The researchers demonstrated that the brain’s immune cells, called microglia, are key players in the problem. First, the microglia become activated by the body’s immune response. The activated, “annoyed” microglia produce inflammatory immune molecules known as cytokines and chemokines, which in turn have widespread effects throughout the brain. They are particularly harmful for oligodendrocytes, the brain cells responsible for making myelin, the fatty substance that insulates nerve fibres and helps nerves transmit signals more efficiently. Reduction in the nerves’ insulation translates into cognitive impairment.

Examining tissue samples

The scientists also analysed samples of brain tissue from human subjects who participated in the team’s ongoing clinical trial of CAR-T cells for spinal cord and brain stem tumours. Using post-mortem tissue samples, the researchers confirmed that microglia and oligodendrocytes appear dysregulated in the same way the team had observed in mice after CAR-T therapy.

In mice, the research team tested strategies to resolve the cognitive problems. They gave a compound that depleted microglia in the brains of the mice for a two-week period. After that transient depletion, the microglia  returned in the brain in a normal, non-reactive state. The mice were no longer cognitively impaired.

The researchers also gave the mice a medication that enters the brain and interferes with signals from damaging chemokines, blocking a specific receptor for these molecules.

“That alone rescued cognition,” Monje said, adding that the researchers are now exploring how to safely translate the two strategies – transiently depleting microglia or interrupting chemokine signals – in people who have had CAR-T cell therapy.

“This research further illustrates that there is a unifying principle underpinning brain fog syndromes,” said Monje, a member of the Stanford Cancer Institute. “And this particular study is so exciting because not only have we identified the cells central to this pathophysiology, we’ve found a molecular target we can investigate to treat it.”

Source: Stanford Medicine

Categories : CancerTags :

Case Reveals a Rare Side Effect of Cancer Immunotherapy

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The genetically modified CAR-T cells meant to treat the cancer themselves turned cancerous

Depiction of multiple myeloma. Credit: Scientific Animations

Some forms of blood cancer, such as multiple myeloma and lymphoma, are malignant diseases that originate from immune cells, specifically lymphocytes. In recent years, CAR-T cell therapies have become an essential part of the treatment of patients whose lymphoma or multiple myeloma has relapsed. This involves genetically modifying the patient’s own T lymphocytes (T cells) in order to specifically recognise and eliminate the cancer cells using a chimeric antigen receptor (CAR).

One special case is the subject of an article published in Nature Medicine. A 63-year-old patient with multiple myeloma developed T cell lymphoma in the blood, skin and intestine nine months after undergoing CAR-T cell therapy at the University Hospital of Cologne. The tumour developed from the genetically modified T cells that were used in the treatment.

The initiators of this collaborative project, Professor Marco Herling, managing senior physician at the University of Leipzig Medical Center and Dr Till Braun, research group leader at the University Hospital of Cologne, have world-renowned expertise in understanding the rare but difficult-to-treat T cell lymphomas. “This is one of the first documented cases of such lymphoma following CAR-T cell therapy. The findings of this study will help us to better understand the risks associated with the therapy and possibly prevent them in the future,” says Professor Maximilian Merz, who led the current study as corresponding author together with Professor Marco Herling from the University of Leipzig Medical Center. 

The researchers discovered that it was not just current genetic alterations of the T cells that caused the tumour. Pre-existing genetic changes in the patient’s haematopoietic cells also played a role. The researchers used cutting-edge technologies to study the tumour’s development in detail. Various methods of next-generation sequencing – an advanced, high-throughput technology for analysing DNA and RNA sequences – were used to study the phenomenon. Whole-genome sequencing was used to identify genetic alterations, while single-cell RNA sequencing analysed the transcriptome of the CAR-T cells to investigate genes and signalling pathways.  

These methods had previously been developed in close collaboration between the research groups of Professor Merz at the University of Leipzig Medical Center and Dr Kristin Reiche at the Fraunhofer IZI. The close collaboration between clinicians and basic scientists in the field of CAR-T cell therapy allowed for the case to be analysed in a very short time. The University of Leipzig Medical Center is one of the leading centres in Europe for the treatment of multiple myeloma with CAR-T cells and of T cell lymphoma. “This case provides valuable insights into the emergence and development of CAR-bearing T cell lymphoma following innovative immunotherapies and highlights the importance of genetic predispositions for potential side effects,” says Professor Merz, Senior Physician at the Department for Hematology, Cell Therapy and Hemostaseology at the University of Leipzig Medical Center. 

The researchers are planning further scientific studies to better understand similar cases and identify risk factors. The aim is to be able to predict and prevent such side effects after CAR-T cell therapies, which are currently being used more and more widely, in the future. The high relevance of the topic of secondary tumours after CAR-T cell therapy has now been highlighted in a second scientific paper. The same research team submitted a manuscript to the high-impact journal Leukemia that systematically summarises this patient case and the nine other recently published cases of T cell lymphoma from CAR-T cells worldwide. Normally, it takes several weeks to months for peer reviewers to accept a scientific paper for publication. In this case, the manuscript was accepted for publication within a day. “It is important to create a real, data-based awareness of the rarity of this complication, at far less than one per cent, and the mechanisms by which it occurs,” says Professor Herling.

Source: Universität Leipzig

Categories : AllergiesTags :

Immunotherapy Lets Children with High-threshold Allergy Safely Eat Peanut Butter

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Photo by Corleto on Unsplash

Children with high-threshold peanut allergy who ate gradually larger doses of store-bought peanut butter achieved significantly higher and long-lasting rates of desensitisation compared to those who avoided peanuts, according to a new study led by researchers at the Icahn School of Medicine at Mount Sinai.  

Results of the trial appear in NEJM Evidence. 

“Our study results suggest a safe, inexpensive and effective pathway for allergists to treat children with peanut allergy who can already tolerate the equivalent of at least half a peanut, considered a high-threshold peanut allergy,” said Scott Sicherer, MD, director of a food allergy institute at Mount Sinai and lead author of the paper. “Our findings open the gateway to personalised threshold-based treatments of food allergy and will encourage additional studies that delve deeper into peanut and other foods for this approach that might be a game-changer for the majority of people with food allergies.”   

The most common approach to a food allergy is to avoid the food, but in recent years peanut oral immunotherapy – medically supervised, very gradual daily feeding of increasing amounts of pharmaceutical-grade peanut protein – has become an option for individuals with peanut allergies.. However, studies that led to Food and Drug Administration approval of an injected biologic and oral peanut immunotherapy have specifically focused on people who react to very small amounts of food allergens, such as half a peanut or less (considered a low-threshold peanut allergy).

“Years ago, when people with milk and egg allergies were advised to undertake strict avoidance, our team initiated studies that found most people with milk and egg allergies could tolerate these foods in baked goods, which changed the global approach to these allergies,” said Julie Wang, MD, Professor of Pediatrics at the Icahn School of Medicine, clinical researcher at the Jaffe Food Allergy Institute, and co-senior author of the paper. “The research team recognised that more than half of people with peanut allergy can tolerate half a peanut or more, and thought that this group of people might be treatable if we took a different approach to peanut oral immunotherapy. We were thrilled to find that this treatment strategy was even more successful than we had anticipated.”  

To test this hypothesis, the study team recruited 73 children ages 4 to 14 years old. Study participants were assigned, at random, to either test the new treatment strategy or continue avoiding peanuts. The children in the peanut-ingestion group began with a minimum daily dose of 1/8 teaspoon of peanut butter and gradually increased their dose every eight weeks over the course of 18 months, ending at one tablespoon of peanut butter or an equivalent amount of a different peanut product. All dose increases took place under medical supervision. None of the study participants in the peanut-ingestion group had severe reactions or needed epinephrine during home dosing  and only one received epinephrine during a supervised dosing visit.  

Following the treatment regimen, children from the peanut-consuming cohort participated in a feeding test, carefully supervised by the study team, to evaluate how much peanut they could eat without an allergic reaction. All 32 children from the peanut-consuming group who participated in the feeding test could tolerate the maximum amount of 9 grams of peanut protein, or three tablespoons of peanut butter. By contrast, only three of the 30 children from the avoidance group who underwent the feeding test after avoiding peanuts for the duration of the study could tolerate this amount.  

Because the trial took place during the COVID-19 pandemic and some families preferred avoiding close encounters indoors, some did not return to the study site for the feeding test. Using a common statistical technique to account for the children who missed the feeding test, the team reported that 100 percent of the ingestion group and 21 percent of the avoidance group tolerated an oral food challenge that was at least two doses more than they could tolerate at the beginning of the study.  

To test if the response to treatment was durable, children in the peanut-ingestion group who could tolerate nine grams of protein during the feeding test went on to consume at least two tablespoons of peanut butter weekly for 16 weeks and then avoided peanuts entirely for eight weeks. Twenty-six of the 30 treated children who participated in a final feeding test after the eight-week abstinence period continued to tolerate nine grams of peanut protein, indicating that they had achieved sustained unresponsiveness to peanuts. The three participants from the avoidance group who could eat nine grams of peanut protein without reaction at the earlier food test were considered to have developed natural tolerance to peanuts. A comprehensive analysis of data collected from all 73 study participants revealed that 68.4 percent of the peanut-ingestion group achieved sustained unresponsiveness, while only 8.6 percent of the avoidance group developed a natural tolerance.   

“These study results are very exciting and a huge step forward in personalizing food allergy treatment,” concluded Dr. Sicherer, the Elliot and Roslyn Jaffe Professor in Pediatric Allergy and Immunology at Mount Sinai. “My hope is that this study will eventually change practice to help these children and encourage additional research that includes this approach for more foods.”  

In addition to expanding the work to more foods and validation studies of their approach, the Mount Sinai study team aims to determine a better way of identifying individuals with higher thresholds, because the best way to do so currently requires a feeding test that is bound to cause an allergic reaction.  

Source: The Mount Sinai Hospital / Mount Sinai School of Medicine

Categories : CancerTags :

New Combination Immunotherapy for Melanoma and Breast Cancer

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3D structure of a melanoma cell derived by ion abrasion scanning electron microscopy. Credit: Sriram Subramaniam/ National Cancer Institute

A research team at the Medical University of Vienna led by Maria Sibilia has investigated a new combination therapy against cancer. This therapy employs systemic administration of the tissue hormone interferon-I combined with local application of Imiquimod. Promising results were seen in topically accessible tumours like melanoma and breast cancer models: the therapy led to the death of tumour cells at the treated sites and simultaneously activated the adaptive immune system to fight even distant metastases. The findings, published in Nature Cancer, could improve the treatment of superficial tumours such as melanoma and breast cancer.

In recent years, immunotherapies have had significant success in the treatment and cure of a wide range of cancers. However, for some patients, these agents are still not sufficiently effective. As part of a preclinical study, Maria Sibilia, Head of the Center for Cancer Research at the Medical University of Vienna, therefore investigated the effects of a combination immunotherapy consisting of systemic administration of the tissue hormone interferon (IFN)-I and local imiquimod therapy. Imiquimod is an active substance that activates the innate receptors TLR7/8 and used to treat basal cell carcinomas. The researchers employed various preclinical mouse tumour models of melanoma and breast cancer. What both tumours have in common is that they are accessible to local therapy and often form distant metastases.

Effective for local tumours and distant metastases

Immunotherapies use the body’s own immune system to fight cancer cells. Plasmacytoid dendritic cells (pDCs), which are activated by Imiquimod via TLR7/8, play an important role in this process. The study showed that oral imiquimod stimulates pDCs to produce the tissue hormone IFN-I. This sensitised other dendritic cells and macrophages in the tumour environment to topical imiquimod therapy, which inhibited the formation of new blood vessels via the cytokine IL12 leading to the death of tumour cells.
The combination immunotherapy not only had an effect on the treated tumours, but also on distant metastases. It reduced the formation of new metastases thus preventing tumour relapses and increasing the sensitivity of melanomas to checkpoint inhibitors.

“These findings illustrate that the combination of systemic treatment with imiquimod or IFN-I and topical therapy with imiquimod has the potential to expand treatment options for patients and improve therapy outcomes in locally accessible tumors such as melanoma or breast cancer,” emphasizes Maria Sibilia.
“Topical treatment of the primary tumor with imiquimod is essential for this combination therapy with systemic IFN-I to be effective at the treated site and also to clear distant metastases,” adds Philipp Novoszel, MedUni Vienna, one of the first authors of the study.

The results suggest that this therapeutic strategy has the potential to improve treatment outcomes in superficial and thus locally accessible tumors such as melanoma and breast cancer – on the one hand through therapy-associated cancer cell death at the locally treated tumors, but also through the induction of a T cell-induced anti-tumor immune response at distant metastases, which is further enhanced by checkpoint inhibitors.

“Our aim is to continue developing immunotherapeutic strategies in order to improve the long-term prospects for patients who are not yet responding well to these agents,” says Maria Sibilia, who is also Deputy Head of the Comprehensive Cancer Center of MedUni Vienna and University Hospital Vienna.
“As systemic interferon is a well-known cancer therapy and dendritic cells are activated in a similar way to our preclinical models, we believe that the new combination therapy can show an effect in patients,” adds Martina Sanlorenzo, dermato-oncologist at MedUni Vienna and co-first author of the study.

Publication: Nature Cancer
Systemic IFN-I combined with topical TLR7/8 agonists promotes distant tumor-suppression by c-Jun-dependent IL-12 expression in dendritic cells
Sanlorenzo M, Novoszel P, Vujic I, Gastaldi T, Hammer M, Fari O, De Sa Fernandes C, Landau AD, Göcen-Oguz BV, Holcmann M, Monshi B, Rappersberger K, Agnes Csiszar A, Sibilia M
DOI: 10.1038/s43018-024-00889-9; https://www.nature.com/articles/s43018-024-00889-9

Source: Medical University of Vienna

Categories : Cancer Cardiovascular DiseaseTags :

How Checkpoint Immunotherapy also Increases the Risk of Cardiovascular Disease

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Source: Wikimedia CC0

Cancer immunotherapy is known to also make patients more vulnerable to heart attack and stroke. A new study led by researchers at NYU Langone Health points to a possible explanation for this side effect: the treatment interferes with immune regulation in the heart’s largest blood vessels.

This new work focused on immune checkpoint inhibitors, which work by blocking molecules embedded on the surface of cells – immune checkpoints – which normally serve as “brakes” that prevent excess immune activity, or inflammation. Some tumours are known to hijack these checkpoints to weaken the body’s defences, so by blocking the checkpoints, the treatments enable the immune system to kill tumour cells.

Unfortunately, this treatment type may also trigger damaging levels of inflammation in the heart, brain, stomach, and other organs, the researchers say. For example, past studies have shown that about 10% of those with atherosclerosis have a heart attack or stroke following cancer treatment. Until now, the specific mechanisms behind this issue had remained unclear.

To address this question, the research team explored at a cellular level how immune checkpoint inhibitors interact with immune cells within arterial plaques. A genetic analysis by the study authors showed that the same type of immune checkpoints targeted by cancer therapies also appear in arterial immune cells, establishing a link between checkpoint inhibitors and cardiovascular events.

“Our findings provide new insight into how a drug intended to target tumours can also prompt a heightened immune response in arteries and increase risk of heart disease,” said study co-senior author Chiara Giannarelli, MD, PhD. “Cancer patients and their physicians should be aware that they may need to monitor for new heart concerns following cancer treatment,” added Dr Giannarelli.

For the current study, published in Nature Cardiovascular Research, the researchers analysed the genetic activity of thousands of immune cells collected from the plaques of 50 men and women undergoing a surgical procedure to address atherosclerosis.

The investigators also explored how type 2 diabetes, a known risk factor for both cancer and heart disease, may make those with atherosclerosis even more vulnerable to the ill effects of checkpoint inhibitors, adds Dr Giannarelli, also an associate professor in the Department of Pathology at NYU Grossman School of Medicine. As part of the study, the team assessed immune checkpoint activity in arterial tissue collected from eight patients with diabetes and four healthy volunteers. Notably, none had a history of atherosclerosis. The results showed that the diabetes patients had less measurable communication between checkpoints, which in turn can prompt increased inflammation.

Other experiments further revealed that taking immune checkpoint inhibitors might make it harder to combat atherosclerosis. Under normal circumstances, physicians typically prescribe low-fat diets to reduce plaque buildup and inflammation. Indeed, the researchers’ experiments in rodents confirmed that such diets boost communication between immune checkpoints within arteries. However, cancer patients may be at a disadvantage because their therapy, by blocking these same checkpoints, may counteract the anti-inflammatory benefits of fat reduction.

“Our findings highlight how cancer, diabetes, and heart disease do not exist in a vacuum, and that it is critical to consider how targeting one of these conditions can affect the others,” said study co-senior author Kathryn J. Moore, PhD. “Now that experts have a better understanding of the interplay between these diseases, they can begin to explore new strategies to lower the risk of unintended health concerns caused by their treatment,” added Dr Moore. She cautions that the study did not directly assess immune checkpoint behaviour in cancer patients. The team plans to do so in future investigations, she adds.

Source: NYU Langone Health

Categories : Cancer NeurologyTags :

A Way to Make Glioblastoma Cells Visible to Immune Cells

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MRI scan showing brain cancer. Credit: Michelle Monje, MD, PhD, Stanford University

Patients with glioblastoma typically survive less than two years after diagnosis, even with cutting-edge therapies. The latest immunotherapies have been unsuccessful, likely because glioblastoma cells have few, if any, natural targets for the immune system to attack.

In a cell-based study, scientists at Washington University School of Medicine have forced glioblastoma cells to display immune system targets, potentially making them visible to immune cells and newly vulnerable to immunotherapies. The strategy involves a combination of two drugs, each already FDA-approved to treat different cancers.

The study is online in the journal Nature Genetics.

“For patients whose tumours do not naturally produce targets for immunotherapy, we showed there is a way to induce their generation,” said co-senior author Ting Wang, PhD, professor of medicine and Department of Genetics head at WashU Medicine. “In other words, when there is no target, we can create one. This is a very new way of designing targeted and precision therapies for cancer. We are hopeful that in the near future we will be able to move into clinical trials, where immunotherapy can be combined with this strategy to provide new therapeutic approaches for patients with very hard-to-treat cancers.”

To create immune targets on cancer cells, Wang has focused on stretches of DNA in the genome known as transposable elements. In recent years, transposable elements have emerged as a double-edged sword in cancer, according to Wang. His work has shown that transposable elements play a role in causing tumours to develop even as they present vulnerabilities that could be exploited to create new cancer treatment strategies.

For this study, Wang’s team took advantage of the fact that transposable elements naturally can cause a tumour to churn out random proteins that are unique to the tumour and not present in normal cells. Called tumour antigens or neoantigens, these unusual proteins could be the targets for immunotherapies, such as checkpoint inhibitors, antibodies, vaccines and genetically engineered T cell therapies.

Even so, some tumours, including glioblastoma, have few immune targets produced naturally by transposable elements. To address this, Wang and his colleagues, including co-senior author Albert H. Kim, MD, PhD, neurosurgery professor, have demonstrated how to purposely force transposable elements to produce immune system targets on glioblastoma cells that normally lack them.

The researchers used a combination of two drugs that influence the epigenome, which controls gene activation. When treated with the two epigenetic therapy drugs, the tightly packed DNA molecules of the glioblastoma cells unfurled, triggering transposable elements to begin making the unusual proteins that could be used to target the cancer cells. The two drugs were decitabine, which is approved to treat myelodysplastic syndromes, a group of blood cancers; and panobinostat, which is approved for multiple myeloma, a cancer of white blood cells.

Before investigating this strategy in people, the researchers are seeking ways to target the epigenetic therapy so that only the tumour cells are induced to make neoantigens. In the new study, the researchers cautioned that normal cells also produced targets when exposed to the two drugs. Even though normal cells didn’t produce as many neoantigens as the glioblastoma cells did, Wang and Kim said there is a risk of unwanted side effects if normal cells create these targets as well.

In ongoing work, Wang and Kim are investigating how to use CRISPR molecular editing technology to induce specific parts of the genome in cancer cells to produce the same neoantigens from transposable elements that are common across the human population. Such a strategy could give many patients’ tumours – even different cancer types – the same targets that could respond to the same immunotherapy, while sparing healthy cells. There are then multiple possible ways to go after such a shared target, including checkpoint inhibitors, vaccines, engineered antibodies and engineered T cells.

Source: Washington University School of Medicine

Categories : CancerTags :

Oestrogens are Implicated in More than Just Breast Cancers

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Photo by National Cancer Institute on Unsplash

Oestrogens are known to drive tumour growth in breast cancer cells that carry its receptors, but a new study by Duke Cancer Institute researchers unexpectedly finds that oestrogens play a role in fuelling the growth of breast cancers without the receptors, as well as numerous other cancers.

Writing in the journal Science Advances, the researchers describe how oestrogens not only decrease the ability of the immune system to attack tumours, but also reduce the effectiveness of immunotherapies that are used to treat many cancers, notably triple-negative breast cancers. Triple-negative breast cancers are an aggressive form of disease that are negative for oestrogen, progesterone, and the HER2 receptor proteins.

Informed by retrospective analysis of patient data and experiments in mice, the researchers found that anti-oestrogen drugs reversed the effects of oestrogens, restoring potency to immunotherapies.

“The treatment for triple-negative breast cancer has been greatly improved with the advent of immunotherapy,” said senior author Donald McDonnell, PhD, professor at Duke University School of Medicine.

“Developing ways to increase the anti-cancer activity of immunotherapies is a primary goal of our research,” McDonnell said. “Here we have found a simple way bolster the effectiveness of immunotherapy for this type of breast cancer and the benefit was even seen in other cancers, including melanoma and colon cancers.”

McDonnell and colleagues, including lead author Sandeep Artham, a postdoctoral associate in the McDonnell lab, focused on a type of white blood cell called eosinophils, which are typically activated during allergic reactions and inflammatory diseases.

Eosinophils have recently been identified as important in tumours, and a phenomenon called tumour associated tissue eosinophilia, or TATE, is associated with better outcomes among patients with multiple types of cancer, including colon, oesophageal, gastric, oral, melanoma and liver cancers.

In their studies, the Duke team described how oestrogens decrease the number of eosinophils and TATE in mice. The hormone contributes to increased tumour growth in oestrogen receptor-negative breast cancer tumours and in melanoma tumours, which do not rely on oestrogen receptors for tumour growth.

Conversely, anti-oestrogen therapies inhibited oestrogen receptor signalling and enhanced the efficacy of immunotherapies, slowing tumour growth.

“These findings highlight the importance of oestrogen-receptor signalling as a regulator of eosinophil biology and TATE and highlight the potential near-term clinical application of anti-oestrogen drugs to increase the benefits of immunotherapies in multiple tumour types,” McDonnell said.

He said clinical trials are being planned using an investigational anti-oestrogen drug called lasofoxifene among patients with triple-negative breast cancers.

Source: Duke University Medical Center

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Better Response to Lung Cancer Immunotherapy with Combination Treatment

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Lung cancer metastasis. Credit: National Cancer Institute

In research published in Nature Communications, scientists have tested a combination of treatments in mice with lung cancer and shown that these allow immunotherapies to target non-responsive tumours.

The study findings, from Francis Crick Institute, in collaboration with Revolution Medicines, show that targeting tumours in different ways simultaneously might increase response to treatments.

The scientists tested a combination of tool compounds in mice with lung cancer. These compounds were used to represent:

  • Targeted drugs which block a cancer-causing protein called KRAS G12C. These have been approved for use in lung cancer, but often fail to benefit patients in the long term because the tumours develop resistance to these medicines over time.
  • Immunotherapy drugs. These are designed to stimulate the immune system to fight the tumour, but only 20% of people with lung cancer respond, as tumours often block immune cells from entering.

The researchers combined a newly identified KRAS G12C inhibitor, with a compound that blocks a protein called SHP2, which inhibits cancer cells and can also activate tumor immunity.

These two inhibitors were combined with an immune checkpoint inhibitor, which blocks proteins that help the cancer cells hide from the immune system.

Source: Francis Crick Institute