All Grants

This grant enables the purchase a Beckman-Coulter Optima MAX-XP Tabletop Ultracentrifuge. It is required for the optimized protocol for ribosome profiling for DIPG samples.

Most DIPGs are triggered by a specific genetic event that impacts the way brain cells regulate DNA activity. In effect, DIPG cells begin to awaken parts of the genome that are generally kept quiescent. Some of these genomic regions may produce retroviral elements. Under normal circumstances, these retroviral elements can be toxic when highly active, but DIPG cells appear to utilize, or at least tolerate, the presence of retroviral elements. Understanding which of these genomic elements are specifically activated in DIPG, and which produce proteins, may provide unique insights into how DIPG cells function, leading to opportunities for novel therapeutic approaches in this deadly childhood brain cancer.

Provide additional resource to ensure CBTN can advance data analyses of DMG tumors at a quicker pace and disseminate this information to researchers around the globe who are committed to this area of impact. Core Goals include:
1) Move quickly to process, analyze and code DMG data and release to researchers
2) Drive investigation and data use to identify and targets, potential use of existing therapeutics, and other opportunities to inform and develop clinical trials
3) Development of presentations, grants, and manuscripts

With ChadTough Defeat DIPG support, we have created the first Neuro-Immuno-Oncology (NIO) fellowship program. Neuro-immuno-oncology is an emerging subspecialty representing a promising therapeutic avenue for treating patients with cancers of the central nervous system (CNS). The goal of the one-year clinical NIO fellowship is to gain expertise in using immunotherapy to treat pediatric patients with brain and spinal cord tumors and to better understand and manage the neurological complications of immunotherapies such as CAR T cell therapies. Fellows round on admitted patients receiving CAR-T therapy for CNS tumors and participate in outpatient clinic visits as well, learning the neuro-critical care and neuro-immuno-oncology skillsets that are needed to manage robust immunotherapy-induced inflammation in delicate CNS structures such as the pons. At the completion of the program, each fellow will have developed the necessary clinical, research, scholarly, and teaching skills to become an academic leader in the field of neuro-immuno-oncology.

DIPGs bear a dismal prognosis due to their unique location in the pons and unusual epigenetic mutations (histone mutations) that make them the most challenging cancer to treat. As a result we have no effective therapies leading to invariable fatality of children diagnosed with DIPGs. In order to tackle this major obstacle, multiple investigators at the University of Michigan have launched DIPG research programs from basic science experiments, animal model experiments and clinical trials in DIPG patients. Since the launch of the Chad Carr Pediatric Brain tumor center, we have made many exciting discoveries that challenge our understanding of DIPGs and force us to think out of the box to understand their unique biology and leverage this information to develop effective therapies. One such discovery is related to metabolic addiction of DIPG cancer cells to sugars and nutrients to enable them to uncontrollably grow. Interruption of these addictive pathways as a major strategy to combat cancer has created a lot of excitement in the field. Research programs led by five laboratory heads at the University of Michigan have discovered metabolic addiction in DIPGs ranging from ongoing clinical trials to preclinical work in DIPG cells and animal models.

A major obstacle to this research is the lack of proper equipment, specifically a mass spectroscopy instrument, that enables measurement of metabolic pathways in DIPG cells. This has created a major issue for DIPG researchers and has significantly slowed down the pace of our research.

We propose to purchase and house this instrument jointly in the Koschmann and Venneti laboratory space, where multiple DIPG investigators can easily access the it. Rapidly running DIPG samples will facilitate a faster and more effective pace of DIPG research, spanning clinical trials and preclinical testing with metabolic inhibitors at U of M.

In 2018, Oncoceutics (now Chimerix) launched an Expanded Access Program (EAP) for a drug called ONC201, which showed promise for treating children with DIPG. The ChadTough Foundation and Michael Mosier Defeat DIPG Foundation (now joined as the ChadTough Defeat DIPG Foundation) supported this effort to make the drug available to patients who had no other treatment options, as standard therapies had little success in managing DIPG. ONC201 is a small molecule that works by targeting specific pathways involved in cancer cell growth and survival. In preclinical studies and early trials, it demonstrated anti-tumor effects, particularly against tumors with the H3K27M mutation, which is present in most DIPG cases. This mutation drives the growth of DIPG, making it especially difficult to treat with conventional methods. Through the Expanded Access Program, patients with no remaining treatment alternatives were able to receive ONC201 under a compassionate use framework while clinical trials were ongoing. This program provided early access to ONC201 for children with DIPG who were not eligible for clinical trials, offering a potential lifeline and advancing knowledge of the drug’s safety and efficacy. The support from both foundations for the EAP reflected their joint mission to accelerate research and treatment options for children with DIPG. Their backing helped ensure that more children could benefit from innovative therapies like ONC201, contributing to the broader effort to develop effective treatments for this devastating disease.

Our foundation is deeply committed to advancing research that brings new hope to children battling DIPG / DMG. One of the most significant ways we've done this is by supporting the pioneering work of Dr. Mark Souweidane at Weill Cornell Medical College, one of the world’s foremost experts in DIPG research and treatment. Dr. Souweidane’s research focuses on developing innovative, targeted therapies to directly deliver treatment to the brainstem, where DIPG tumors are located.

This partnership holds special significance for our foundation. Chad Carr, from one of our founding families, bravely participated in Dr. Souweidane’s clinical trial during his fight against DIPG. Chad’s participation was part of a larger effort to bring forward new treatment approaches for this devastating disease, including Dr. Souweidane’s groundbreaking work on convection-enhanced delivery (CED), a method that allows drugs to bypass the blood-brain barrier and reach the tumor directly.

The impact of supporting Dr. Souweidane’s research is profound. His innovative techniques have opened new avenues of hope for families facing DIPG, providing more effective, targeted treatment options that are desperately needed. By funding his lab, we are accelerating the development of therapies that could significantly improve outcomes for children with DIPG.

Our foundation proudly provided financial support to Dr. Cynthia Hawkins' lab at SickKids in Toronto—one of the world’s leading pediatric brain tumor research centers. Dr. Hawkins is a globally recognized expert in pediatric brain cancer, with a particular focus on DIPG, one of the most aggressive and challenging childhood cancers.

Our funding helped fuel critical discoveries that advanced the understanding of DIPG, especially its genetic drivers, such as the H3K27M mutation. This mutation is key to DIPG's growth and resistance to traditional treatments, and Dr. Hawkins’ work has been instrumental in identifying new biomarkers and uncovering potential therapeutic targets. These discoveries are vital steps toward developing innovative, more effective treatments for children diagnosed with this devastating disease.

By funding Dr. Hawkins’ research, we were not just supporting lab work—we were contributing to a global effort to find answers and solutions for DIPG. Our donors made it possible for this research team to move science forward in a meaningful way, accelerating the path toward better treatment options and giving hope to families around the world.

The breakthroughs made during the years of our support serve as a powerful reminder of the importance of sustained, focused investment in cutting-edge research. By continuing to support labs like Dr. Hawkins’, we are helping to pave the way for future clinical trials and innovative therapies that could one day change the course of DIPG.

DIPG are fatal tumors without effective treatments and 90% of patients die within 1.5 years of diagnosis. Most regimens used in adults or other types of childhood cancers either produce no effect or only marginally improve survival for DIPG patients. Therefore, research is urgently needed to develop effective therapies for children with DIPG. Cancer cells exhibit aberrant and accelerated metabolism that can be leveraged to kill tumor cells. We have discovered that DIPG cells are addicted to glucose in order to provide energy to support their uncontrolled proliferation. Surprisingly, DIPG tumor cells also use glucose to modify a canonical mutation found in more than 80% of DIPGs. Targeting this pathway constitutes a potential therapy that simultaneously tackles two dysfunctional pathways in DIPGs, thus improving chances of therapeutic success by overcoming the ability of cancer cells to resist treatment via redundant biological pathways. We propose a research program to define the role of and dependence on glucose in DIPG. Our work will (a) help uncover a critical but yet characterized central pathway in DIPG tumor cells and (b) provide the groundwork for innovative therapies that simultaneously interrupt two critical and interrelated pathways in DIPGs.

Diffuse intrinsic pontine glioma (DIPG) is an aggressive pediatric tumor occurring in the pons accounting for ~80% of brainstem gliomas. Each year, DIPG affects over 300 children in the U.S., with a median survival of only 11 months. Due to the tumor location, surgical resection is impossible, while resistance to current treatments makes the prognosis dismal. Chimeric antigen receptor (CAR) T cells are a new, targeted immunotherapy that has had remarkable success in curing children with hematological malignancies. This technology must now be translated to children with DIPG. B7-H3 is a protein expressed on nearly all DIPG but not on normal brain, enabling CAR T cells to selectively target tumor cells. Our Seattle Children’s team just completed BrainChild-03 (NCT04185038), a first-in-human phase 1 clinical trial for children with DIPG and found the planned highest dose, 100 million cells, to be safe. Some patients have also had remarkable clinical benefit, including two patients still on trial 2.5 years from their diagnosis without progression. Unfortunately, these encouraging results have not been universal, but a new era of combinatorial clinical trials is now possible.

ONC206 is a small molecule derived from ONC201, an allosteric agonist of the protease ClpP, that has shown even greater benefit in initial laboratory studies. ONC201 has had promising clinical efficacy against DIPG, but - as with CAR T cells - the positive outcome is not universal. While there is hope that ONC206 is more effective for children than ONC201, these agents will need to be combined with other therapies to reach a cure. Based on clinical success of B7-H3 CAR T cells, along with the advancement of ONC206 to clinical trials, in this project we will evaluate the combinatorial benefit of these agents together, determining their best time sequence for a future clinical trial for children with DIPG.

Current treatment options for DMG, such as radiation therapy, only extend survival by a few months. In a recent clinical trial, our group treated pediatric DMG patients with Delta-24-RGD (DNX-2401), a modified virus with tumor-selective and destroying ability which improved survival in the majority of our patients. To further enhance the anti-tumor effects of DNX-2401, we generated Delta-24-RGDOX (DNX-2440), that now incorporates a protein (OX40L) to activate the patient's resident immune T cells towards killing cancer cells. Recent work from another clinical trial has reported the role of engineering a separate protein (chimeric antigen receptor (CAR) on immune T cells in enhanced killing of the DMG cells. In this project, we will combine DNX-2440 with engineered CAR T cells and assess the role of this combination therapy in improving survival outcomes for DMG patients. The proposed study will potentially open new horizons for novel combination therapies for children with DMG.

It is hard to imagine a worse tumor than diffuse intrinsic pontine gliomas (DIPGs). These are aggressive brain tumors that grow in the most sensitive part of children’s brains, and are always fatal–usually within
months of diagnosis. One major reason that DIPGs are difficult to treat is that they vary from patient to patient, and even from cell to cell within a tumor. To effectively treat DIPG or any other tumor, the goal is to get rid of all the cancer cells inside it. One strategy that scientists are exploring is to focus on genetic changes that are common across all DIPG tumors. These are like the “early events” that happen in cancer development and are found in all the tumor cells. If we can target these changes, we will have a chance at removing the tumor completely. However, with DIPGs it has been hard to find these early events that could be targeted with drugs.

In DIPGs, one of the early events is changes in the number of chromosomes they harbor. Normally, healthy cells have 23 pairs of chromosomes, each with a short and long arm. But DIPGs, like most aggressive tumors, lose or gain entire chromosome arms. These changes help the tumor grow. Each of these chromosome arms can contain hundreds to over a thousand genes, and it is extremely difficult to understand the overall effects of changing them all simultaneously. We have a hypothesis: these whole-arm changes in chromosomes may create unique vulnerabilities in the tumor cells that can be targeted with new and unconventional treatments. By focusing on these shared changes, our hope is to find novel therapies that are effective against DIPGs and offer new hope to children and families affected by this devastating disease.

Brain function involves the firing of neurons to deliver information. Unfortunately, neuronal activity also promotes diffuse intrinsic pontine glioma (DIPG) growth and disease progression. We have found that like normal glial cell types, DIPG cells can become integrated into neural circuits. Some DIPG cells form synapses with neurons, similar to a normal glial precursor cell that receives synaptic inputs from neurons. This synaptic communication between neurons and DIPG cells results in electrical currents that promote DIPG growth. Membrane depolarization alone is sufficient to drive DIPG proliferation1, but we don’t yet know
which voltage-sensitive mechanisms promote tumor progression. I used CRISPR/Cas9-based genetic screening to identify key genes for DIPG cells to interact with neurons and grow in the tumor microenvironment. My screening results suggest that voltage-gated calcium channels may play crucial roles in converting electrical activity to promote DIPG growth. Therefore, I propose to study voltage-sensitive calcium channel signaling in DIPG, and compare it with neural stem and progenitor cells in the developing brain. The proposed research on voltage-dependent regulation of DIPG may elucidate novel therapeutic targets for DIPG.

Pediatric brain cancers affect nearly 4,000 children each year. Recent research emphasizes the vital role of neuron-cancer communication in their development. Neurons stimulate cancer growth, and cancer cells, in turn, boost neuron activity, creating a harmful cycle that leads to seizures and fast tumor growth. However, many aspects of this communication remain unclear due to the diverse nature of brain cancers. Studying these cancers is challenging due to the brain's functional and biochemical diversity. Understanding them requires an in-depth analysis spanning various components and levels, from protein chemistry to tumor spread. Holistic characterization of the biochemical interplay between neurons and cancer cells is critical to understanding brain cancer pathophysiology and represents a promising direction for therapy development. While basic neuron-cancer interactions are well-described, key components and mechanisms of communication and cancer pathogenesis remain unexplored.

In Michelle Monje's lab, my research aims to uncover the molecular aspects of key cell surface signaling in pediatric gliomas, mainly Diffusive Intrinsic Pontine Glioma and Diffusive Midline Glioma (DIPG/DMG). Initially, I will identify crucial proteins involved in neuron-glioma interactions using advanced mapping techniques, providing a detailed blueprint of the cell surface in DIPG/DMG and other pediatric gliomas. Subsequently, I will delve into the roles of these proteins using molecular and cellular approaches. Finally, I will develop and assess new therapies in mouse models. These findings have the potential to revolutionize our understanding of glioma cell surface signaling and inspire innovative treatment strategies.

H3K27M Diffuse Midline Gliomas (DMGs) including Diffuse intrinsic pontine gliomas (DIPGs) are lethal brain tumors with a universally poor prognosis1,2. Current treatments are not effective, leading to emergence of resistance and uniform lethality. Hence, there is an immediate and unmet need to develop effective therapies. Our previous research has shown that H3K27M-DIPGs profoundly rewire their metabolic needs to sustain growth and survival5. Our current proposal aims to investigate one such important metabolic pathway that is hijacked by the H3K27M DIPGs to maintain a favorable epigenetic state and mediate radiation
resistance. Our proposed research will a) unravel key tumor promoting roles of this pathway and, crucially, b) facilitate the development of targeted therapies in the future.

Our study aim is to develop a novel therapeutic strategy for DIPG patients by targeting a molecule called CD155. We have discovered CD155 on the surface of both human and murine DIPG cells, and our preliminary data show that inhibiting this molecule not only enhances tumour cell killing by the immune system, but also directly inhibits growth of DIPG cells. To understand the former, we will analyse proteins secreted by those immune cells and study how they change in response to antibodies that block CD155. To understand the latter, we will study the genes that change in tumour cells after treatment with antibodies targeting CD155. That will help us understand how this two-pronged approach works and how best to use it to advance therapies for DIPG patients.

To test whether treatment with anti-CD155 antibodies is an effective therapy for DIPG, we will treat tumour-bearing mice with these antibodies and study their tumour growth and survival. Notably, it is unclear if anti-CD155 antibodies can cross the blood-brain barrier and enter the tumour. Therefore, we will compare the efficacy of administering the antibody via three different routes: 1. Systemic injection into the abdomen of the mouse, 2. Injection into the cerebrospinal fluid and 3. Injection into the tumour itself. These studies will not only increase our understanding of DIPG biology but will also pave the way for improved immunotherapies for patients with this devastating disease.

Recent studies show that DIPG tumors are made up of different types of cells, including stem-like cells that drive tumor growth and a smaller number of more mature, differentiated cells. The research focuses on how n3-polyunsaturated fatty acids (n3-PUFAs), a type of fat, might help push the tumor cells to become more differentiated, making them less aggressive and less likely to form tumors.

Aim 1 will study how the n3-PUFA metabolic pathway influences the differentiation of DIPG cells. Early findings suggest that n3-PUFAs are key for this process, and blocking their action prevents the cells from maturing. The researcher will use genetic techniques to modify enzymes responsible for n3-PUFA metabolism and examine how these changes impact cell growth, survival, and differentiation. They will also explore how n3-PUFAs affect the activity of certain proteins that control cell identity, aiming to understand how these lipids influence the tumor’s behavior.
Aim 2 will test whether increasing n3-PUFA levels in DIPG cells can reduce tumor formation in animal models. The researcher will manipulate the n3-PUFA pathway to see if it can shift the tumor cells to a more mature state that is less likely to grow into tumors.

This study could provide insights into using n3-PUFAs as a novel treatment strategy for DIPG by encouraging the tumor cells to become less malignant through differentiation.

DIPG is characterized by a mutation in proteins that structurally support the DNA named histones. A direct consequence of this mutation is the increase of a chemical modification on non-mutant histones deposited by an enzyme named EP300. The histone mutation also prevents glioma cells from differentiating into mature and non-proliferative brain glia cells. I hypothesize that interfering with the activity of EP300 can revert the oncogenic function of the histone mutation, allow tumor cell differentiation and, consequently, prevent tumor progression. Indeed, our initial experiments suggest that these glioma cells require EP300 for survival. Now, this project aims to validate EP300 as a promising target for DIPG therapy. To do so, I will test a vast panel of drugs able to disrupt the activity of EP300 in DIPG cells to assess their capacity to reduce tumor cell viability. Promising drugs will be evaluated for their ability to reach the brain at therapeutic concentrations and then tested in mouse models for their efficacy in preventing tumor growth and improving survival. As single agent therapy is unlikely to result in complete tumor regression, I will test EP300 targeting agents in combination with drugs commonly used in the context of cancer treatment to identify drug combinations that potentiate the effect of EP300 inhibition. Finally, using genetic silencing technology, I will remove EP300 from glioma cells and evaluate for changes in gene expression, tumor cell proliferation and differentiation. I will also test whether EP300-depleted tumor cells can still form tumors in mice to evaluate the potential of EP300 as a therapeutic target. In conclusion, this work seeks to change the treatment paradigm of these pediatric malignancies by exploring EP300 as a new actionable therapeutic target. Importantly, preclinical testing of EP300 pharmacological agents and drug combinations will inform future clinical trials for these universally fatal tumors.

ONC201 has emerged as one of the most promising therapies for DIPGs. Yet, the precise mechanisms by which ONC201 kills DIPG tumor cells remains to be elucidated. Our research project will investigate how ONC201 simultaneously interrupts energy producing pathways and DNA-associated modifications (called epigenetic modifications) in DIPG tumor cells. We will first carefully dissect out how ONC201 changes metabolism in DIPG tumor mitochondria to alter epigenetic pathways in tumor cells. Then we will try to understand how DIPG tumor cells change their metabolic and epigenetic profiles to escape ONC201 treatment and use this knowledge to provide therapies to overcome ONC201 resistance.

We face many major challenges in the development of treatment approaches that increase the survival of DIPG/DMG patients. Two of the most vexing of these are i) therapies that penetrate the brain’s highly protective blood-brain barrier (BBB) in sufficient quantitates to show an anti-DIPG effect in vivo, and ii) therapies that are selective for DIPG cells without causing systemic toxicities. Given traditional cytotoxic chemotherapies do not pass through the BBB, our best hope of achieving long-term survival is if we can develop treatment modalities that combine and amplify the benefits of standard-of-care radiotherapy (RT), and then exploit the unique biology of DIPG as a consolidation strategy.

Seeking to address these key areas of unmet need, my research has focused on optimizing the BBB penetrant therapy ‘paxalisib’, for the treatment of DIPG. Over the last four years, we have discovered that the cellular targets of paxalisib, i.e., the PI3K-pathway (PIK3CA, mTOR) are critical for DIPG cell survival. However, clinically, it has proven difficult to elucidate the full benefit of paxalisib due to numerous systemic and cellular responses that combine to reduce its efficacy. But thanks to the work of our laboratory, we now know what these rescue mechanisms are, and how to target them to drive a potent and sustained anti-DIPG response.

This Fellowship will enable the preclinical optimization of strategies using paxalisib as a backbone to inform the established adaptive clinical trial PNOC022 (NCT05009992), currently testing radiotherapy in combination with paxalisib and ONC201. Our team is responsible for the preclinical and case study results that underpins this international clinical trial. Specifically, this Fellowship will optimize the use of paxalisib in combination with RT by taking into consideration the effects of corticosteroids, optimize therapies that modulate insulin feedback driven by systemic PI3K-inhbition, and develop consolidation strategies that simultaneously target DIPG-specific escape mechanisms following partial PI3K-
pathway inhibition.

Many previous studies of DIPG focused on studying growth pathways within the tumor cells themselves. However, DIPG tumors receive powerful signals from surrounding neurons that cause the tumors to grow. We will take an innovative approach by searching for new pathways through which neurons signal to DIPG cells. To do this, we designed an experiment in which neurons and DIPG cells are grown together in a dish and found that DIPG growth increases tenfold when neurons are present. Next, we obtained a library of small molecule drugs that block a variety of neuronal signaling pathways. Many of these drugs are known to be brain-penetrant and are FDA-approved for epilepsy, depression, and other neuropsychiatric conditions. Our preliminary studies identified several promising lead compounds that slow glioma growth, including potassium channel blockers, calcium channel blockers, and dopamine modulators. In this fellowship project, we will extend these experiments to additional cell lines and perform further experiments to identify the receptors and characterize how the compounds are affecting glioma growth. Then we will test the lead compounds in mouse models of DIPG. We anticipate that our studies will identify new pathways of neuron-to-glioma communication as well as multiple lead compounds with different mechanisms of action that can be rapidly advanced to clinical trials for DIPG patients.

Currently, the spotlight in treatment of cancer is on immunotherapy, an encouraging strategy that has brought hope to many patients. However, DIPGs are “cold” tumors, which means they are barely noticeable to the patient’s own immune system. Consequently, the lack of a basal anti-tumor immune response is being a major drawback for immunotherapeutic-based treatments for DIPG. Thus, it is mandatory to “warm” these tumors in order to implement a successful immunotherapy for DIPGs.

Delta24-RGD is an oncolytic adenovirus currently being tested in clinical studies for the treatment of brain tumors, including DIPGs. Delta24-RGD selectively replicates in tumor cells, killing the host cell while spreading more viral particles. Nevertheless, Delta24-RGD triggers an inflammatory environment that “warms” and unmasks the tumor to the immune system. As a result, Delta24-RGD mediates the establishment of an anti-cancer immune response that could eventually be potentiated by immunostimulatory molecules. In this regard, Delta24-RGD can also act as delivery vector to express immunostimulatory molecules in the tumor site enhancing an anti-DIPG immune response while avoiding the risk of systemic toxicity.

Here we propose to develop a Delta24-RGD virus encoding immunostimulatory genes as a comprehensive approach against DIPG, invigorating innate and adaptive arms of the anti-tumor immune response in a single treatment. The dual anti-tumor effect of this virus (oncolysis and immunostimulation) will be assessed in relevant DIPG models. If successful at the end of this project, we will be in the position to propel a phase I/II clinical trial with this new oncolytic virus.

Pediatric high-grade gliomas such as diffuse intrinsic pontine glioma (DIPG) are the leading cause of brain cancer-related death in children. While enormous progress has been made in recent years for many forms of cancer, DIPG remains seemingly intractable, indicating that fundamental aspects of glioma growth are not yet well understood. A lack of effective treatment for DIPG can be partially attributed to the diffusely infiltrating characteristics of the tumor. Rather than creating a dense and circumscribed tumor cell mass, DIPG diffusely invades the normal brain tissue, making resection impossible and providing the opportunity for glioma cells to interact with other cells in their environment, including neurons. Recent work from our group has demonstrated that neuronal activity powerfully drives DIPG progression. We aim to gain further insight into the active communication between neurons and glioma cells in order to shift our view of DIPG from an isolated disease to an active and integrative system and leverage these findings for more effective therapeutic strategies. Medications that decrease neuronal activity are commonly given to children with DIPG to treat anxiety and nausea. Some of these medications increase signaling of GABA, which has an inhibitory effect on neurons and could thereby inhibit DIPG growth. On the other hand, it is possible that DIPG cancer cells may directly respond to GABA, which could either increase or decrease DIPG growth. We aim to determine the role of neuron-to-glioma GABA signaling in DIPG and its effect on DIPG growth to inform whether commonly-used drugs that affect GABA signaling may be beneficial or detrimental to give to children with DIPG.

DIPG tumor cells feed on vast quantities of glucose to support their uncontrolled growth. Increase reliance on glucose leads to the increase production of a metabolite called lactate. Although long considered as a waste product, it has been discovered in recent years that lactate is used by the cancer cells to aid their growth and division. Yet, the precise mechanisms by which DIPG tumor cells utilize lactate for abnormal cell growth remains to be elucidated. Our research project is impactful, because it will investigate the dual functions of lactate serving as both (1) a fuel for energy producing pathways and (2) a substrate for a recently discovered DNA-associated modification. Our goal is to target this critical dependency on lactate, thereby, killing DIPG cells using an integrated epigenetic and metabolic approach.

The immune system plays a crucial role in the anti-tumor response. Despite the encouraging clinical results obtained in other types of tumors, the particular immunological environment of the diffuse intrinsic pontine glioma (DIPG) has hindered the use of this approach as an efficacious alternative to the current treatment of DIPG. Even so, our group has demonstrated the feasibility of using oncolytic viruses, a type of bioimmunotherapy, at different levels of this disease.

As we have shown, the preclinical administration of the oncolytic adenovirus Delta-24-ACT (with the capacity to awake the patients’ immune system) in DIPG is safe, but its efficacy can be further enhanced. Incorporating additional transgenes to Delta-24-ACT can be a feasible strategy to achieve a sustained in situ delivery of additional molecules, potentiating the effect of oncolytic virotherapy while overcoming the risk of exacerbating systemic toxicity. On the other hand, preliminary data from our lab indicates that the expression of TIM-3 in the tumor microenvironment (TME), specifically in the myeloid compartment, could pose a resistant mechanism to anti-DIPG therapies. Moreover, we have demonstrated that TIM-3 is a potential therapeutic target in DIPG and that its blockade mediates potent anti-tumor responses in DIPG mouse models.

Here we propose to develop the Delta-24-ACT virus encoding a TIM-3 inhibitory molecule as a comprehensive approach against DIPG, invigorating innate and adaptive arms of the anti-tumor immune response in a single treatment. The dual anti-tumor effect of this virus (oncolysis and immunostimulation) will be assessed in relevant murine and humanized DIPG models. If successful at the end of this project, we will be in the position to propel a phase I/II clinical trial with this new oncolytic virus: Delta-24-DMG-ACT.

After decades of intense research it has become clear that DIPGs are highly treatment resistant tumors that unlikely will be cured by monotherapy. To effectively eliminate DIPG cells, a combination of different treatment modalities, such as radio-, chemo- and immunotherapy, is likely needed to reach clinical effect. In this project we propose to study a combination therapy in which we incorporate both radiotherapy and two drugs, Paxalisib and Givinostat, which are currently in clinical trials for DIPG (Paxalisib) or for children with Duchenne muscle dystrophy (Givinostat). We recently identified that very low doses of Givinostat can kill DIPG cells growing in a dish and that this drug can enhance the tumor-killing effect of radiotherapy and Paxalisib. Furthermore, preliminary data suggest that Givinostat treatment results in local inflammation in DIPG-bearing mice, a sign that the immune system is fighting the tumor cells, and reprogramming of immune cells that support DIPG growth. However, although promising, Givinostat by itself was insufficiently potent to cure mice from DIPG, suggesting that it should be used in combination with other treatment modalities. It is the aim of this project to test different treatment regimens incorporating Givinostat, Paxalisib and radiotherapy in DIPG mouse models to identify the most optimal combination therapy and dosing scheme. Besides looking at survival benefit of these treatments, we will study the impact on the immune cells within the tumor and its surrounding healthy brain tissue. By obtaining a better understanding of the biological effect of this drug combination we can prepare for the inclusion of Givinostat on a backbone of Paxalisib in future clinical trials, either as a radio/chemotherapy combination or as a backbone for immunotherapy. As such, the results from this study open the door for therapeutic combinations that ultimately may lead to an increased progression free- and overall survival of DIPG patients.

It is widely recognized that the tumor cells’ (“the seed”) surrounding ecosystem, known as the tumor microenvironment (“the soil”), plays an active role in supporting tumor survival and promotion, immune evasion, and chemoresistance. The tumor microenvironment (TME) is comprised of tumor cells, a myriad of normal and immune cells, extracellular matrix, blood vessels and many other factors, which are all constantly cross-talking and influencing each other. Within the TME, tumor cells secrete an array of chemical signals that hijack normal tissue support systems and avoid destruction from the immune system.

Within the DMG-H3K27a (formerly known as DIPG) tumor mass, the dominant non-tumor cell population are glioma-associated microglia and macrophages. In healthy brain and spinal cord tissue, specialized immune cells known as microglia and macrophages play a key role in innate immunity by fighting infections, clearing cellular debris, and eliminating tumor cells. However, in the DMG-H3K27a TME, tumor cells co-opt microglia and macrophages into secreting growth factors that promote tumor growth and progression instead. The identity of the microglial-derived growth factors and their effect on tumor biology is not well characterized. In our preliminary studies, we have discovered and identified microglial-derived growth factors that DMG-H3K27a tumor cells are dependent on, which represents new avenues for developing targeted therapies.

The primary objectives of this research are to 1) investigate the biological consequences of microglial secretion of growth factors and its effect on DMG-H3K27a tumor growth and progression in vitro and 2) evaluate the therapeutic potential of targeting the cell-cell communication between microglial cells and tumor cells by using blood brain barrier penetrant, clinically relevant drugs, and a neutralizing antibody we have developed in vivo. Ultimately, these findings provide further insights on DMG-H3K27a biology and inform future therapy paradigms.

Diffuse Intrinsic Pontine Glioma (DIPG) is a lethal pediatric brain tumour with no therapeutic options currently available. Although ongoing research continues to develop our understanding of this disease, we have had limited success developing treatments. As we have come to learn more about DIPG, several studies report increased activity in the RAS/MAPK axis, a pathway that regulates cell survival. Therefore, if we could target these cancer cells and prevent the activation of this pathway, we may kill tumour cells and prevent tumour cell survival. In collaboration with Dr. Roman Melnyk’s group, my project will investigate a targeted toxin that can specifically kill tumour cells by stopping this pathway. By identifying a cell surface receptor specific to tumour cells Dr. Melnyk’s group can construct a molecule that binds to the surface and cleaves RAS to kill these cells thus reducing tumour size. I will be testing these molecules in cells from patient samples as well as in mouse models to support its efficacy and safety. As these molecules are large and potent, they must be delivered directly into the tumour. This means it will require a direct delivery technique such as Convection Enhance Delivery, which is currently used in patients. To test this molecule and technique in a mouse model I will be using an osmotic pump. Using the pump, a catheter can directly deliver the molecule into the brain to the tumour therefore killing tumour cells. By having a treatment that uses both a targeted molecule and a direct delivery technique I believe that this therapy will prolong the lives of DIPG patients, so that it may no longer be lethal.

ONC201 is an investigational drug that has shown promising effects in preclinical models of DIPG and is currently undergoing clinical trials in patients. Despite promising early results, these tumors eventually return. Understanding how ONC201 is working in DIPG and how DIPGs develop resistance is critical to develop methods to combat tumor recurrence. My preliminary data from ONC201-treated DIPG models suggest that ONC201 disrupts how DIPGs extract energy from sugar molecules. Further, this data shows that once these processes are broken, ONC201-treated DIPG cells begin to use other sources of energy, such as the amino acid glutamine. I therefore hypothesize that resistance to ONC201 develops when DIPGs develop alternative strategies to meet their energy demands. Understanding the exact mechanism by which resistance may occur will highlight potential combination treatment strategies to increase ONC201’s effectiveness and improve patient outcomes. In this research proposal, I will seek to understand 1) how ONC201 slows DIPG cell growth by interfering with sugar metabolism and 2) to learn if blocking other fuel sources, such as glutamine, can overcome resistance to ONC201. In this proposal, I outline three aims: 1) I will determine changes in the cellular energy production machinery before and after ONC201 treatment, 2) I will determine how sugar and amino acid metabolism change following ONC201 in recurrent DIPG tumors in mice, and 3) I will use combination treatment strategies to overcome ONC201 by targeting the compensatory metabolic pathways used by DIPG cells to evade the inhibitory mechanism of action of ONC201.