Targeting the Cancer Epigenome: The Effect of Specific Histone Lysine Methyltransferase Inhibition in Canine B-Cell Lymphoma

Canine lymphoma is one of the most common cancers in dogs. While some breeds appear more at risk than others, all can be affected. Although it is often treatable, canine lymphoma can rarely be cured. A continued understanding of the mechanisms causing lymphoma in dogs and identification of novel therapies are needed to improve survival in dogs with lymphoma.

One area of research that has been actively explored and provided exciting breakthroughs for human lymphoma is epigenetics, or alterations in how genes are turned on and off independent of the DNA sequence. One way in which this occurs is due to modifications of the proteins that interact with DNA called histones. Various modifications to these histones can result in genes being turned on or off, leading to the development of cancer. One particular enzyme that modifies histones, EZH2, has been found to play a role in some human lymphomas. However, this has been unexplored in canine lymphoma. Given the striking similarities between human and canine lymphoma, the objective of this work is to characterize the function and role of EZH2 in canine lymphoma.

The investigators will utilize an EZH2 inhibitor to study EZH2 in canine lymphoma cells. The information obtained from this study will help guide the future development of this targeted inhibitor for use as a novel therapy to treat canine lymphoma.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 02309

RESEARCHERS

Angela McCleary-Wheeler, DVM, PhD; University of Missouri, Columbia
Amount: $5,000

Efficacy of Cannabidiol (CBD) for the Treatment of Canine Epilepsy

Epilepsy is the most common neurologic condition in dogs. Approximately 20-30% of dogs receiving standard therapy remain uncontrolled for their seizures. Additionally, the side effects of the antiepileptic drugs (AED) are often unacceptable. Thus, there is a need for an AED that is efficacious with minimal side effects. Cannabidiol (CBD), a prominent non-psychotropic component of the Cannabis sativa plant, has been shown to have anti-convulsant properties. While CBD offers promise as a treatment for canine epilepsy, controlled studies are needed to prove its effectiveness.

In this randomized, double-blinded, placebo-controlled, crossover clinical trial, client-owned dogs with uncontrolled epilepsy will be enrolled following a full seizure evaluation, including bloodwork and magnetic resonance imaging. The canine patients will first receive either a placebo or CBD in addition to their standard AED protocol and then the opposite drug in this crossover designed study. Seizure frequency and medication side effects will be monitored by owners using a seizure log and questionnaire. Regular CBD plasma concentrations, routine bloodwork and serial physical examinations will be monitored by the investigator.

The primary goal of the study is to determine the efficacy of CBD in the treatment of canine epilepsy. If CBD is effective in decreasing seizure frequency, it has the potential to improve the quality and length of life for dogs with uncontrolled epilepsy, and add a much-needed tool for veterinarians in the treatment of canine epilepsy.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 02323

RESEARCHERS

Stephanie McGrath, DVM, MS; Colorado State University
Amount: $10,000

Precision Medicine for Canine Lymphoma

The clinical response of dogs with lymphoma to multi-agent chemotherapy is highly variable. Although up to 85% of dogs respond initially, some relapse within weeks, while others enjoy remission times of two years. This heterogeneity in clinical response is in part explained by the recognition that “lymphoma” is not a single disease entity, but consists of different subtypes that can be characterized on a molecular level by mutations in specific genes.

As in human medicine, it follows that different lymphoma subtypes, driven by different molecular mechanisms, may respond better to therapies that are specifically selected to inhibit the driver mechanisms within that patient’s tumor. Recent work using sophisticated genetic sequencing tools (next-generation sequencing (NGS)) has begun to shed light on the different molecular subtypes of canine B cell lymphoma, and specific therapies aimed at targeting patient-specific driver genes and pathways are being developed.

To enable targeted therapies to move into the clinic, a personalized diagnostic tool must be developed that can rapidly and cost-effectively determine the mutational profile of a patient’s cancer allowing selection of the most effective drug for that patient. The investigators aim to develop a NGS diagnostic test that can be employed on standard biopsy samples to identify molecular drivers of a patient’s lymphoma (personalized diagnostics), enabling the most appropriate targeted therapy to be selected for that patient. In addition, they aim to determine whether specific mutational profiles within canine lymphoma identified by their NGS panel, are predictive of clinical outcome.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 02441

RESEARCHERS

Nicola Mason, BVetMed, PhD
Trustees of the University of Pennsylvania
Amount: $5,000

Tumor-permissive Collagen Signatures in Canine Mammary Gland Tumors: Development of Prognostic Markers and Targeted Therapies for Improved Outcomes

Mammary gland tumors (MGT) are the most common malignancies in intact female dogs, and the resulting premature death and morbidity in this sub-population of dogs represents a significant health problem. While genetic alterations within tumor cells can promote their uncontrolled growth and ability to spread to distant sites, recent work indicates that normal, non-malignant cells and extracellular matrix (ECM) within the surrounding tumor stroma also regulate the growth and spread of cancer.

The investigators have identified cancer-associated stromal (collagen) signatures in canine MGT biopsy samples that predict clinical outcome better than commonly used markers. These predictive markers may improve the veterinary oncologist’s ability to accurately predict which dogs truly need aggressive treatment from those that do not. Notably, their laboratories have shown that inhibition of a collagen-degrading enzyme (Fibroblast Activation Protein (FAP)) and increasing a tumor suppressive collagen (type III collagen (Col3)) prevent the formation of these tumor-inciting signatures in other species (mouse and human). This work suggests that if these novel targets can suppress tumor-permissive collagen signatures in the dog, we can treat canine MGT more effectively.

The goals of this project are 1) to identify additional collagen signatures which predict clinical outcome in dogs, 2) determine how they direct tumor cell behavior and 3) develop therapies that prevent formation of tumor-inciting collagen signatures in canine MGT. Based on the investigators’ published and preliminary data, they predict that identifying and targeting tumor-inciting collagen signatures will lead to improvements in both diagnosis and treatment of dogs with malignant MGT.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 02489

RESEARCHERS

Susan Volk, VMD PhD
University of Pennsylvania
Amount: $5,000

Prevalence of Bartonella spp. Infection in Dogs with Cardiac and Splenic Hemangiosarcomas within and between Geographic Locations

Splenic masses comprise ~50% of all canine splenic disease. Despite advances in imaging and pathologic definition, the etiology and medical relevance of splenic lesions in dogs are often ambiguous. While some splenic tumors are benign, approximately two-thirds are highly malignant and carry a poor prognosis. Hemangiosarcoma (HSA) accounts for the majority of canine malignant splenic tumors and occurs in many large dog breeds, including mixed breeds.A less common site of HSA localization is the heart (cardiac HSA). Risk factors for both cardiac and splenic HSA remain unclear, confounding development of preventative strategies.

The investigators recently reported a high prevalence of species of the bacterial genus Bartonella in dogs with HSA from North Carolina, suggesting a potential role in the initiation and/or progression of this cancer. Bartonella species exist worldwide and are transmitted by blood-sucking arthropods (e.g. ticks, fleas) and their presence in splenic tissue could potentially be explained by the fact that the spleen is primarily responsible for removal of blood-borne parasites from the systemic circulation.

The investigators will perform a comprehensive examination of the potential association between Bartonella infection and HSA by comparing the prevalence of Bartonella DNA in tumor and blood samples from both splenic and cardiac HSA cases, and also within and between distant geographical locations in the US. Ultimately, demonstration of a robust association between Bartonella infection and the development of HSA may lead to new opportunities for improved diagnosis, treatment and prevention of this devastating cancer.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 02519

RESEARCHERS

Edward Breitschwerdt, DVM
North Carolina State University Office of Sponsored Programs
Amount: $10,000 in 2018, $10,000 in 2019

Evaluation of a New Vaccine for Canine Brucellosis

Canine infection by Brucella spp. constitutes a serious problem for dog breeders and pet owners, leading to the economic burden associated with reproductive loss and veterinary care. Canine brucellosis is also considered a public health concern because of its potential to be transmitted to humans.

Within the US, the disease has reemerged due to the chronic persistence of the organism, low dose for infection, low sensitivity and specificity of the current diagnostic tests, and most importantly, the lack of a protective vaccine for dogs. Historically in the US, brucellosis control efforts for cattle, sheep, goats and domestic pigs have been successful mainly due to the availability of protective and efficacious vaccines.

The goal of the proposed research is to develop a brucellosis vaccine that is safe, stable, free of side effects and efficacious for dogs. Previous CHF funding (Grant #2275-A) has permitted the investigators to successfully engineer a promising live attenuated vaccine candidate, denominated B. canis RM666ΔvjbR.

This study will further investigate the ability of the vaccine candidate to induce appropriate immunity and will also develop a diagnostic assay capable of differentiating naturally infected vs vaccinated animals, necessary for mass vaccination. The development of a safe and highly protective brucellosis vaccine for dogs will significantly impact owners, breeders and human health by limiting the spread of the disease.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 02441

RESEARCHERS

Angela Arenas, DVM
Texas A&M AgriLife Research
Amount: $3,000

Identifying the Disease‐Defining Autoantibodies in Canine Addison’s Disease

Addison’s disease is a common and life‐threatening disorder in dogs in which the body’s immune system destroys the outer layer of the adrenal glands. The adrenal glands produce hormones that are critical for energy metabolism, immune system function, intestinal health, and kidney function. Symptoms of Addison’s disease can mimic other conditions, and as a result, many dogs remain undiagnosed for years.

About one‐third of dogs with Addison’s disease are diagnosed only after suffering an acute adrenal crisis, which can cause a wide range of complications that require emergency stabilization and hospitalization. Today, there is no way to predict which dogs will develop Addison’s disease before they become sick. If such a test were available, veterinarians would be able to evaluate high‐risk dogs before they show signs, helping to prevent disease‐related complications and potentially enabling earlier treatment.

In this study, the investigators will use a novel approach combining gene and protein sequencing to identify the antibodies that target the adrenal glands in Standard Poodles, Portuguese Water Dogs, and English Cocker Spaniels with Addison’s disease. These antibodies are produced by the immune system before the onset of clinical signs. The ability to identify these antibodies would therefore provide a test for early diagnosis.

This research will contribute to progress in developing an important clinical test for Addison’s disease that can help improve the lives of the many dogs at high risk of developing this life‐threatening condition.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 02428

For details and logistics of this project, to include eligibility criteria and how to enroll, please visit Dr. Friedenberg’s page for the Addison’s Disease – Autoantibody Study.

RESEARCHERS

Steven Friedenberg, DVM, PhD
University of Minnesota
Amount: $30,000

Identifying Cellular Mechanisms of Inflammation During Canine Tick-Borne Diseases

Tick-borne diseases are found in all 50 states of the United States and are the most common vector-borne disease diagnosed in people in the US. The predominant disease is Lyme disease, caused by Borrelia burgdorferi and related species (sensu lato). Other important canine tick-borne diseases include those caused by Anaplasma platys, Anaplasma phagocytophilum (Anaplasmosis), Babesia canis, Babesia conradea and Babesia gibsonii (Babesiosis), and Ehrlichia canis, Ehrlichia chaffiensis and Ehrlichia ewingii (Ehrlichiosis).

Many of these diseases also affect people. Dogs can serve as sentinel species for human disease and there are many areas where the immune responses and disease outcomes are very similar in people and dogs, meaning that important lessons can be learned by sharing information between human and animal health (One Health).

The researchers will further investigate the dog’s immune system to determine which immune cells are responsible for the cure or creation of canine tick-borne disease. Through understanding which cells are responsible for causing disease, the goal is to then specifically target the molecules they produce using immunotherapy or immune modulation to improve treatment of tick-borne diseases in all dogs.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 02383

RESEARCHERS

Christine A Petersen DVM PhD
University of Iowa
Amount: $5,000

Genome sequencing and antimicrobial susceptibilities of Escherichia coli isolated from clinical cases of canine pyometra

Pyometra is a potentially life-threatening infection of the canine uterus by bacteria, most commonly Escherichia coli (E. coli). In humans with recurrent infections, E. coli produces biofilm, a layer of polysaccharide that protects the organism from the host immune system as well as antibiotic agents, decreasing treatment efficacy. Current treatments for pyometra are costly, time-consuming, and not without risk to the bitch.

The investigators postulate that biofilm production by E.coli within the uterine lining may be responsible for perpetuating the disease and making treatment difficult. In previous CHF-funded study, the investigators were able to prove that E. coli from clinical cases of canine pyometra is capable of producing biofilm both in the uterus and in laboratory settings.

The purpose of this study is to characterize the presence of ten different genes associated with biofilm production and disease-contributing factors of E. coli organisms to determine if there is an association with those strains of E. coli that produce biofilm and certain disease factors found in other strains of E. coli. Disease factor genes and resistance patterns will be identified, and may serve as targets for new therapeutics directed at the disruption of biofilm in an effort to shorten the duration of treatment of pyometra.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 02512-A

RESEARCHERS

Erin E Runcan, DVM
Ohio State University
Amount: $2,000

Harnessing a Dog’s Own Immune System to Kill Lymphoma Tumor Cells

Lymphoma is the most common malignancy of dogs representing up to 25% of diagnosed cancers. Dogs often develop an aggressive form of lymphoma that is rarely curable, with most unfortunately succumbing to disease within 12 months of diagnosis despite best available chemotherapies.

Dr. Wilson will develop a new treatment to re-train the dog’s own immune system to attack the most common type of canine lymphoma, B-cell lymphoma. In order to accomplish this they will obtain a small number of circulating white blood cells, called T cells, from the blood of affected dogs and insert a gene that will cause the T cell to express a receptor which recognizes the tumor “fingerprint”. After docking with the lymphoma, the T cell will be triggered to mount an immune response against the tumor cells with the specific fingerprint.

This therapy could be used alone or in combination with chemotherapy. Their preliminary data demonstrate that it is possible to genetically modify T cells. Further, they have been able to successfully harvest and grow T cells in the laboratory and return them safely to the dog. These infused cells can be found in the blood and tumor weeks after infusion, showing that it is possible for these cells to survive in the dog. If successful this study will be the first to develop an “in-dog” T-cell therapy targeting a tumor that has historically thought to be untreatable.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 01418

RESEARCHERS

Heather M Wilson-Robles DVM
Texas A&M Research Foundation
Amount: $2,000