Grants

Aggressive brain tumors contain cancer stem cells that drive tumor aggressiveness and recurrence but remain elusive to detect. We have found that they acquire an abnormal sugar coating when they transition from a less aggressive to a more aggressive type. At Johns Hopkins, we have recently developed a specialized magnetic resonance imaging (MRI) technique that can detect these sugars which we hope to use as an imaging biomarker for the presence of glioma cancer stem cells in diffuse midline glioma (DMG).  Since this stem cell detection method does not require any injection of contrast agents it is easy and safe to implement with currently used MRI techniques. Building upon this innovation our ultimate goal is to develop and implement, from pre-clinical orthotopic mouse models to DMG patients, our new MRI technique to visualize high mannose levels in DMG stem cells. If succesful, this new imaging technique may then serve as a molecular imaging biomarker for predicting tumor aggressiveness and more importantly to diagnose tumor recurrence following surgery for further radiotherapy planning. Our first two scanned patients showed that mannose imaging is clinically feasible, with a never observed contrast that is distinct from that obtained with conventional MRI techniques currently.

Children diagnosed with diffuse midline glioma (DMG), a devastating brain cancer, face heartbreaking odds. Radiation, the only current treatment, provides limited benefit and causes serious, lifelong side effects. Our mission is to create safer, more effective therapies that give children a real chance to survive and thrive.

This project develops a new therapy using engineered immune cells, CAR T cells, designed to attack tumor cells while sparing normal cells. We are advancing a groundbreaking two-part strategy:

• Dual-target CAR therapy – We engineer a child’s immune cells to target two key molecules on tumor cells, reducing the chance of cancer escape and improving long-term effectiveness.
• Focused ultrasound – This non-invasive technology temporarily opens the brain’s protective barrier, enabling CAR T cells to reach tumors more efficiently and boosting their therapeutic activity.

Unlike current CAR T cells being tested in clinical trials, our preclinical studies use models that faithfully replicate both DMG tumor biology and the brain’s immune barriers. This enables rigorous evaluation of safety, delivery, and tumor-killing activity, generating critical data to accelerate the translation of a well-validated CAR therapy to first-in-child trials.

Diffuse midline gliomas (DMGs) are some of the worst childhood cancers, typically marked by an H3K27M mutation, which is an excellent target as it is expressed by nearly all the tumor cells. 

We have designed a way to repetitively layer H3K27M attack ‘orders’ in an “onion-like” nanoparticle, which intensely and rapidly stimulates the immune system. This approach cured a large percentage of mice harboring DMGs and, in dogs and adults, has generated remarkable immune responses. In addition, as an off-the-shelf treatment, this vaccine is rapidly available and much easier to give than treatments which require prolonged times for generation. Rapidly retraining the immune system against H3K27M has great potential to improve outcomes for a desperate group of children and their families.

We are hoping to try this in a clinical trial for children with H3K27M+ DMG after standard local radiation treatment. This funding request encompasses the first arm who will receive a year of vaccine therapy. In addition, blood will be drawn so that scientists can examine how the patient’s immune system is responding to the H3K27M nanoparticle vaccine. With a successful trial, we anticipate rapid translation into a Phase 2 combination trial.

Diffuse midline glioma (DMG) is an aggressive, incurable pediatric brain tumor requiring new therapies. CAR T cells are a targeted immunotherapy in which some of a patient’s white blood cells are removed, engineered to fight a specific cancer target, and then returned to seek out the tumor. Seattle Children’s and St. Jude have each opened Phase 1 clinical trials of B7-H3 CAR T cells delivered intracranially to children with DMG. While St. Jude’s trial is ongoing, Seattle Children’s completed their trial and found a median survival of over 19 months (compared to the historical 11.2 months) with 3 patients now alive 51, 52, and 59 months from diagnosis. While these results are encouraging, not all children have benefited – likely due to the tumor’s immune microenvironment that opposes the activity of CAR T cells. Here, two leading cellular therapy programs will come together to define the best treatment that can be given prior to CAR T cells, with the aim of disrupting the tumor’s local immune environment to pave a path for CAR T cells to be most effective. Ultimately, this work will define the best treatment regimen prior to CAR T cells and define future clinical trials.

Diffuse midline glioma (DMG) is a uniformly fatal brainstem tumor of childhood with no effective therapies. Given the failure of chemotherapy and radiation against DMG, we are pursuing strategies to enable effective immunotherapy for this disease. A major roadblock to immunotherapy is that DMG cells effectively ‘hide’ from the body’s immune system. We now understand that DMG cells rely on “epigenetic” modifications, or chemical marks that regulate whether genes are turned on or off. This presents a selective vulnerability in DMG cells that makes them sensitive to epigenetic drugs. We have shown that use of existing, FDA-approved drugs to target epigenetic regulators can activate immune signaling in DMG cells and cause expression of new targets that can be recognized by the immune system, creating an avenue for converting this immunologically ‘cold’ tumor into a ‘hot’ one that can be effectively targeted. In order to validate this strategy for translation to patients, it is necessary to use a mouse model with an intact immune system, unlike the immunodeficient mouse models that are typically used to model human brain tumors.  We will employ a powerful DMG mouse model in collaboration with Dr. Oren Becher in order to test the effect of epigenetic therapy on immune signaling in DMG, with the goal of rapid translation of these therapies to patients who urgently need better treatments.

Diffuse midline glioma (DMG) is a devastating brain and spinal cord tumor that occurs in children and is universally fatal, killing most patients within one year. New approaches using the body’s immune system to attack DMG have started to show promise for patients. Chimeric antigen receptor or “CAR” T cells are an immune based cancer treatment that involves taking white blood cells from a patient, reprogramming them to seek out and attack tumor cells, then reintroducing these cells back into the patient where they destroy the cancer. One type of CAR T cell seeks out a target called GD2, a sugar molecule that sits on the outside of DMG tumor cells. Using GD2-seeking CAR T cells in mouse models, we observed that they work best when the first dose is given directly into the tumor, followed by doses into the fluid that coats the brain and spinal cord. The CAR T cells in the tumor seem to be sending a signal to the subsequent CAR T cells in the fluid, recruiting them to come fight the tumor as well. The goal of this proposal is to better understand the immune signals coming from DMG tumors and active T cells to help design the best CAR T cell trial for patients.

First, we will evaluate the blood and cerebral spinal fluid from 10 patients with DMG specifically looking at proteins related to the immune system. We will then use patient tumor cells and CAR T cells in the lab to identify what immune proteins are released when CAR T cells encounter and kill DMG tumor cells. Thus, this proposal aims to understand the baseline immune system of DMG patients, and how the signals from the immune system change after tumor cells encounter CAR T cells. Our goal is to create optimal dosing strategies of GD2-seeking CAR T cells and design better CAR T cells for clinical trials to help cure these awful tumors in children.

Diffuse intrinsic pontine glioma (DIPG) is a rare, fatal brain cancer for which there are no good treatments.  Part of the problem is that, doing business as business is currently done, there are no financial incentives for discovering medicines for DIPG. Traditional companies see that potential for return on investment is low due to the high failure rate of medicines in the clinic, the low patient population, and the added difficulties of treating children.  Financial incentives should not be the barrier that stops the identification of life saving medicines: the need for effective treatments for these children is paramount. Since current business models do not support DIPG drug discovery, new business models are clearly needed, and this is a key to our approach. We are part of a global team, working under the umbrella of M4K pharma, using open science and collaboration to revolutionize the way affordable new medicines are discovered and developed. Kinases are important and attractive drug targets, and over 80 kinase inhibitors have been approved by the FDA for clinical use. Evidence suggests that the kinase ALK2 is an excellent target for DIPG drug discovery. Our goal is to advance an ALK2 inhibitor into clinical trials.

Our M4K team has identified a selection of high quality ALK2 inhibitors and are triaging them to determine whether we have a suitable clinical candidate that meets our high standards. These include excellent ALK2 inhibitory potency in cells, high selectivity over other kinases, and chemical properties that will allow for oral dosing, safety, and delivery of high concentration to the region of the brain where the tumor is located.  In parallel to our ongoing analysis of current compounds, we are designing and making new inhibitors of ALK2 in case no current compound meets our high standards, and to provide a backup compound if we determine that we already have a compound that is suitable for advancement. This application, “Leveraging open science and collaboration to identify clinical quality ALK2 inhibitors for DIPG” seeks funding to help us with our goal of discovering effective, safe, and affordable medicines for DIPG patients. The Drewry lab seeks funding for two specific aims. In aim 1 we will screen ALK2 inhibitors from all M4K partners in our state-of-the-art NanoBRET cellular assays, for both our primary target ALK2, and off target kinases that we need to have selectivity over. The data generated in this assay is critical to our overall mission. In aim 2 we will design, synthesize, and evaluate new compounds designed to be address issues and potential issues in our current compounds.

Transcription factors can be considered as “molecular switches” that can turn ON or OFF specific sets of genes. The overall objective of this project is to understand how the gene networks up- and downstream of the transcription factor DLX2, and how changes to DLX2 itself, affect brain and DMG development. This will be accomplished in two scientific aims: In Aim 1, we will use advanced genomics and gene-editing technologies to investigate the developing mouse brain (collected from developing mouse embryos). We will determine what other proteins and genes change the behaviour (or function) of DLX2, as well as what proteins and genes are impacted by DLX2. This will help us understand the networks that regulate DLX2, and how normal and abnormal brain development in this region of the brain occurs. In Aim 2, we will manipulate DLX2 in cells that are derived from the DMG tumors of patients, to determine how the cell growth is impacted by changes in DLX2. These manipulated DMG cells will be observed in cell-culture (in vitro) and in live mice where these modified DMG cells have been surgically implanted into newborn mouse brainstem (in vivo).

Despite significant efforts, there has been no improvement in the treatment and outcomes for DIPG (diffuse intrinsic pontine glioma)/DMG (diffuse midline glioma) in the past 50 years. In 2012, the co-discovery that the majority of DMG, including DIPG, have specific mutations of variant histones (known as H3.3 and H3.1) fundamentally changed what we know about these tumors, and as a result, many researchers have redirected their efforts to systemically unravel the underlying biology and to apply these learnings towards the development of new therapies.

Histones help to “wrap” our DNA so that it fits inside the nucleus of the cell. Changes to histones, known as histone modifications, further assist to “unwrap” or “wrap” specific regions of the DNA within the nucleus of the cell so that specific genes or sets of genes can either be expressed or are blocked from being expressed. The more recent application of single cell genomics platforms using DMG samples, including RNA sequencing, support that there is a specific cell of origin for DMGs, an oligodendroglial progenitor cell (OPC). In the adult brain, OPCs eventually become oligodendrocytes that make myelin, a substance that insulates the projections of other brain cells called neurons and coordinates brain function. However, current and proposed therapies for DMG do not target this cell of origin. Our novel work in the emerging field of Cancer Neuroscience addresses the developmental neurobiology of these tumors and through sophisticated and comprehensive analysis of genetic and epigenetic networks and structures, as well as new models (using cell culture and mouse models), we will unlock the underlying biological basis of these tumors towards approaches to novel therapies for DMG.

The Eisenstat laboratory is one of three labs in the world that are expert in understanding the role of the distalless (DLX) class of transcription factors in brain development and the only one focused on applying this knowledge to help solve DMG. The Neuro-oncology laboratory based at the Murdoch Children’s Research Institute (MCRI) and the Brain Cancer Research laboratory based at the Walter and Eliza Hall Institute (WEHI), both affiliated with the University of Melbourne, Australia, have the specialised skillsets and laboratory platforms to perform this work. The MCRI has established and maintained the genetically engineered mouse models lacking Dlx gene function, and has the expertise required for the genetic manipulation of DMG cell lines, including advanced gene editing techniques known as CRISPR. The MCRI also has access to multiple cell-lines derived from patients with DMG which will be used for the these experiments. The WEHI has the specialised equipment required for performing the newborn mouse implantation experiments, as well as the required imaging technology to visualise the tumor development in live mice.

Ultimately, Aim 1 will provide a comprehensive understanding of the role DLX2 plays in normal brain development (and how it interacts with other transcription factors), while Aim 2 will apply this knowledge to how varying levels of DLX2 impacts DMG development. These findings will inform future experiments at the MCRI, including more complex cell culture experiments and sophisticated characterisation of the DLX2 protein itself towards making this transcription factor “druggable”. Our longer-term translational goal is to alter the level of DLX2 in patients with DMG as a novel form of differentiation therapy, so that we may take advantage of the underlying developmental neurobiology of the tumor to change outcomes for DMG patients.

Diffuse Intrinsic Pontine Glioma (DIPG) is a devastating brain cancer that primarily affects children between the ages of 5 and 10. With a poor prognosis, most children diagnosed with DIPG survive only about 9 to 12 months. Current treatments like radiation therapy offer only temporary relief, leaving families and doctors in desperate need of better options.

Our Innovative Approach

Our research is exploring a novel approach to treat DIPG by combining two promising strategies: copper chelation and gene silencing.

1. Copper Chelation: Cancer cells, especially in brain tumors, often contain high levels of copper, which they utilize to grow and resist treatments. We use a drug called TETA to strip the excess copper from the cancer cells, making them weaker and more susceptible to treatment.
2. Gene Silencing: The MYC gene is a major player in tumor growth and aggressiveness. By using small molecules called siRNA, we aim to turn off this gene, thereby slowing down or stopping the tumor growth.

The Delivery System

To get these treatments directly to the tumor cells, we use structures made from red blood cells, known as extracellular vesicles (EVs). These EVs act like delivery trucks, carrying our treatments safely through the body to the brain tumor, ensuring they reach their target effectively.

What We Expect

Combining these two approaches, we hope to:

• More effectively stop tumor growth.
• Increase the death of cancer cells.
• Reduce the tumor cells’ ability to survive.
• Prevent the cancer cells from developing resistance to treatment.

Progress So Far

We have made exciting progress from the start of our study in March 2024.

1. Producing EVs: We successfully created EVs loaded with anti-MYC siRNA.
2. Delivery to Cancer Cells: These EVs effectively delivered the siRNA to DIPG cells in the lab, significantly reducing MYC gene activity.
3. Reducing Tumor Growth: This led to a 50% reduction in cancer cell growth. Combining TETA with MYC silencing showed an even greater effect, making the treatment more powerful.
4. Developing Tools: We designed a high-throughput device to improve the efficiency of loading red blood cells with our therapeutic molecules, aiming to increase production and reduce costs. This plug-and-play device is capable of collecting blood, loading red blood cells with therapeutics, and releasing extracellular vesicles (EVs) into the patients' veins, embodying a circular personalized medicine approach

The Potential Impact

If successful, our approach could revolutionize DIPG treatment, offering a new, targeted therapy that minimizes damage to healthy cells and reduces side effects. This method could also be adapted to treat other types of cancer by changing the drug and RNA content inside the EVs.

Our vision is to provide more effective and personalized cancer treatments, offering new hope to patients who currently have few options. This research holds the promise of improving outcomes for children with DIPG.

High-grade gliomas (HGGs) make up 8-10% of children's brain tumors and are often fatal within two years. These tumors can develop in the cerebral cortex or infratentorial regions like the brainstem. About half of pediatric HGGs occur in midline locations such as the pons, known as diffuse midline gliomas (DMGs), including DIPGs. High-grade gliomas show distinct patterns, with DIPGs typically developing in mid-childhood. DIPGs are highly invasive, making understanding what drives this process to create effective treatments essential.

Our research has shown that, unlike cortical HGGs, DIPGs grow and spread more when implanted into brainstem tissue compared to cortical tissue. Additionally, brainstem microglia (support cells in the brain) enhance the growth and spread of brainstem tumors more than cortical microglia do. This indicates that specific factors in the brainstem environment support DIPGs.

We have identified several genes that are differently expressed between the brainstem and cortical microglia, including CXCL5. This gene is part of the CXCL-ELR+ family, which interacts with the CXCR1/2 receptors and is known to influence cell movement and cancer cell invasion, including in gliomas. Our initial findings suggest that the CXCR1/2 pathway may play a role in DIPG invasion.

With this grant, we aim to test how the CXCR1/2 pathway and related factors contribute to DIPG growth and spread. We will also evaluate whether the key players in this pathway could be potential targets for new DIPG treatments.

Our ultimate goal is to translate these findings into clinical trials, offering new hope to children and families affected by this devastating disease. By supporting our research, you are contributing to the development of targeted therapies that could revolutionize the treatment landscape for DIPG.

Diffuse midline glioma (DMG) is a deadly pediatric brain cancer. Despite radiation treatment, nearly all children diagnosed with the disease succumb to it with a median survival of 12 months. There have been few advancements in treatment, and current treatment has no curative intent. Therefore, there is a significant need to develop new therapeutic strategies to improve the terrible outcomes for these children and improve quality of life for patients and their families. Looking at genes that are turned on or off in a particular type of cancer can be helpful to figure out what is causing the cancer to grow. One such gene which we found to be turned on in DMG is FOXR2. Interestingly, FOXR2 is normally turned off in normal brain. We have previously studied how FOXR2 is turned on and off. When it is turned off, DMG cancer cells die. In this project, we will study how to turn FOXR2 off using small interfering RNA (siRNA) that can be delivered to the brain tumor. We will use patient DMG cell models as well as mouse models of DMG. Ultimately, our goal is to determine whether we can target FOXR2 in DMGs to improve outcomes for children and their families impacted by this terrible disease.

Diffuse Midline Gliomas (DMGs), including Diffuse Intrinsic Pontine Gliomas (DIPGs), are among the most aggressive pediatric brain tumors and the leading source of mortality in pediatric oncology. The median life expectancy of these children remains below 14 months after diagnosis, and nearly none survive beyond the second year. All therapeutic approaches have failed, leaving radiation therapy as the sole palliative treatment that transiently ameliorates the disease. Therefore, finding a curative and feasible alternative for these children is of the utmost importance.  Delta-24-RGD is an oncolytic adenovirus genetically modified to replicate and kill tumor cells selectively while remaining harmless in normal tissues. This biotherapeutic agent has been recently tested in a small number of DIPG patients, validating its safety and showing clues of efficacy. In addition, analysis of patient samples demonstrated the effect of Delta-24-RGD in activating the patient’s immune response against the tumor. Unfortunately, the effect was only transitory, and all patients recurred. Additional genetic modifications of Delta-24-RGD have been explored to potentiate its anti-tumor effect, such as incorporating immunostimulatory transgenes. Despite these upgraded viruses being more efficient in promoting anti-tumor responses, the effect cannot be curative in all subjects. Here, we propose to refine the design of modified oncolytic viruses by considering the intrinsic peculiarities of DMGs. We will arm this virus with molecules that have the capability to trigger effective antitumor immune responses while maintaining a safe profile.  At the end of the project, we expect that the results yielded by this project will show a new, innovative, and efficient therapeutic approach based on oncolytic viruses for DMGs while maintaining a safe profile. These data should place us in a strong position to translate to the clinical scenario a new therapy for children with DMGs, and we expect to find that it offers these children a curative, safe, and feasible alternative.

Diffuse midline glioma (DMG) is a malignant brain tumour arising in children representing a major unmet clinical need, with a 2-year survival rate close to zero. We and others have found that some DMGs have alterations in the MAPK pathway which drives cell growth – drugs targeting this pathway may be initially effective, but eventually the cancer cells escape therapy. We have used DMG cell models to show that this drug resistance can occur in a new way, in which cells slow down and ‘hide’ from drug treatment by temporarily changing their make up in a way that makes the drug ineffective. Having shown that this can occur, we now wish to learn more about DMG cells pull of this trick, by growing them in the lab and determining the precise mechanism that allows them to tolerate exposure to drug. Having done so, we hope to find ways of overcoming it that might be a useful and much-needed therapeutic strategy for children with these tumours. 

Cancer cells secrete lactic acid, creating an inhospitable glucose-poor and lactate-rich tumor environment that would otherwise be lethal to most cells. Recent advances trying to understand DIPG development demonstrated that lactic acid was three times higher in DIPG cells. Furthermore, our laboratory found that the enzyme which makes the lactic acid is higher in tumor tissues analyzed from children with DIPG compared to other lower grade brain tumors. We have identified two non-toxic drugs which reduce lactic acid in DIPG cells. We found that blocking the over-production of lactic acid with these novel chemotherapies, significantly decreased the growth of DIPG cells, with one therapy even curing mice with DIPG.

Our work suggests that DIPG tumors are addicted to high secretions of lactic acid.

With this grant we will test novel, non-toxic drugs that block lactic acid over-production in animals with DIPG tumors. We will also characterize how lactic acid enables DIPG cells to be more aggressive by changes to DIPG DNA structure.

Although lactic acid is greatly over-produced by DIPG cells, it’s unclear what advantage the lactic acid gives to the DIPG tumor cells, because its yet to be investigated. We do have clues from experiments performed in adult cancers. Importantly, in other cancers high lactic acid in tumors promoted the immune escape of tumors and radiation resistance. Lactic acid even decreases the effectiveness of emerging therapies such as CAR-T cells in glioblastoma.

Lactic acid is likely an underlying general resistance mechanism in DIPG which is easily targeted with existing drugs. Giving hope that by reducing lactic acid in DIPG, children would respond better to currently trialed and emerging DIPG therapies, such as radiation or CAR-T.  

Our strategy targets a well reported DIPG characteristic that scientists have not investigated yet. We believe that targeting lactic acid over-production in DIPG is a feasible and novel treatment against DIPG, with the drugs already available and protocols for their use in children already available.

So why are we interested in lactic acid production? We discovered that H3K27M mutated DIPG cells are more sensitive to a copper depletion drug (copper chelator) compared to non-mutated DIPG. Amazingly we found that copper depletion cured 25% of mice bearing the common H3K27M mutated DIPG, as well as increased mouse survival. We demonstrated for the first time that copper depletion has an anti-DIPG cancer effect, which crosses the blood brain barrier and is non-toxic. We performed follow-up work trying to understand why the copper chelation was working against the DIPG cells. These experiments showed that the copper chelator was changing the metabolism in the cells. Specifically, copper chelation was blocking lactic acid production and changing downstream lactic acid effects on DNA structure. We realized there are no studies yet investigating lactic acid effects in DIPG, especially looking for any changes to DNA structure, which is known to be uniquely important in DIPG. Thus, our proposed work could help explain why these mutations lead to DIPG. Normal tissue in the brain is not dependent on copper and lactate over-production at the levels observed in DIPG tumors. Thus, our investigations could provide a novel therapeutic target that would only target cancer tissues and not the surrounding healthy tissue in the brain.

Copper chelation and lactate production drugs are used against other diseases already. The glycolysis pathway has a plethora of drugs available that are active in humans, and in other cancers such drugs are already being utilized in clinical trials. Copper chelation is already given orally to kids with genetic diseases and FDA approved. Thus, our treatment strategies could be easily incorporated into clinicals trials, because we already have information regarding what amounts are safe and effective for use in children. Note that the equivalent same amounts safely given to children with genetic diseases, we have shown to cure some mice with DIPG.