Luteinizing Hormone Receptor Activation Induces Migration and Adhesion in Neoplastic Canine Lymphocytes

Luteinizing hormone (LH) is secreted from the brain (pituitary) in sexually intact dogs to stimulate synthesis of estrogen and testosterone in females and males, respectively. However, LH is secreted at concentrations up to 20 times higher following gonad removal with spaying or castration because hormonal negative feedback is lost. Although LH is considered to be a reproductive hormone, there are dozens of non-reproductive tissues in dogs that contain receptors for LH including immune system cells, specifically lymphocytes.

Lymphoma is a common malignant cancer of dogs involving lymphocytes, and spayed/castrated dogs are reportedly 3-4 times more likely to develop lymphoma. Conventional chemotherapy results in remission in approximately 60-90% of cases with a median survival time of 6-12 months. Preliminary work has identified LH receptors in canine lymphoma tissue and demonstrated LH- receptor-induced proliferation of neoplastic lymphocytes in vitro.

This study aims to determine if LH receptor activation induces adhesion and migration of neoplastic lymphocytes in vitro. Characterizing the role of LH receptor in neoplastic lymphocyte proliferation may help guide future lymphoma treatment options.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 2751

RESEARCHERS

Michelle Kutzler, DVM, PhD; Oregon State University
Amount: $3,000

Identifying Early Stage Ultra-rare Mutations as Predictive Biomarkers of Lymphoma in High-risk versus Low-risk Breeds Within the Dog Aging Project

The most common type of cancer in dogs is lymphoma, with ~80,000 cases diagnosed annually in the United States. Breeds vary in their risk of lymphoma, but it is unclear why there is variation despite considerable effort to identify the genetics of cancer risk and progression in dogs. Cancer typically arises from the accumulation of non-inherited (i.e. somatic) mutations. However, variation among breeds in cancer risk could be due to breed-specific variation in the types of mutations, the rate of accumulation of mutations, or the downstream effects of mutations in healthy dogs.

This study will use novel sequencing technology to test the hypothesis that breed-specific lymphoma risk is due to variation in the frequency and type of rare precancerous mutations. Normally, measuring these low-frequency mutations has been beyond the range of standard sequencing technology, which is limited to detecting mutations present in >1% of cells. The new technology applied here represents a >10,000-fold improvement in accuracy, enabling the investigators to accurately detect a precancerous mutation present at a single site at a frequency of just one out of every 10 million DNA base pairs. By determining if mutation frequency in blood of healthy high-risk and low-risk dogs can predict lymphoma risk, this work could lead to the development of novel tests for the early diagnosis and prognosis of canine lymphoma.

This work has the potential to shed light on the mechanisms that underlie breed-specific variation in lymphoma risk, and in the long term, could lead to the development of novel tests for the early diagnosis and prognosis of canine lymphoma.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 2772

RESEARCHERS

Daniel Promislow, PhD; University of Washington
Amount: $10,000

Reprogramming the Tumor Immune Niche in Canine Hemangiosarcoma

Hemangiosarcoma (HSA) is a common, devastating disease of dogs. The malignant tumor is seen frequently in older Golden Retrievers, German Shepherd Dogs, Portuguese Water Dogs, Labrador Retrievers, and Schnauzers, but it can occur in any dog of any breed at any age. Survival times of dogs with the tumor are short, even with surgical removal and standard of care treatment. Inflammation within the tumor tissue is common in canine HSA, and the immune response may contribute to tumor heterogeneity and prognosis for the dog. Yet, the immunological features in the context of the HSA niche are virtually unknown. The investigators have found that HSA cells have a strong capacity to promote proliferation and differentiation of hematopoietic stem and progenitor cells, with increased inflammatory cytokines, suggesting a niche regulatory function of HSA cells.

This study will focus on understanding the functional relationships between HSA cells and immune cells that contribute to the tumor niche to identify molecular mechanisms that regulate critical signaling pathways in canine HSA. This approach will improve our understanding of the tumor immunity and heterogeneity, as well as aid in patient selection for novel immunotherapies.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 2759

RESEARCHERS

Jong Hyuk Kim, DVM, PhD; University of Minnesota
Amount: $5,000

Optical Coherence Tomography for Margin Evaluation of Canine Skin and Subcutaneous Neoplasms

Skin cancer is common in older dogs and often requires surgery to treat. For these tumors, the best chance of cure is offered if the surgeon can fully remove both visible and microscopic traces of the tumor. Currently surgeons must rely on pathologist’s assessment of tissues after surgery and the success of the procedure will not be known until several days later. This result is important as residual cancer may need further surgery or other treatments like radiation therapy. Additional treatments such as these can result in further risk and discomfort for dogs as well as be an emotional and financial cost for owners. Optical coherence tomography is an emerging diagnostic imaging tool that uses light waves to generate real-time, high-resolution images of tissue at a microscopic level. These images can be used to evaluate for residual disease at the time of surgery giving immediate feedback to the surgeon.

This study will focus on validating this technology for the imaging of surgical margins of canine skin and subcutaneous tumors. If successful, this technology could be used to assess for residual cancer intra-operatively to benefit patients by guiding accurate treatment recommendations.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 2758

RESEARCHERS

Laura Selmic, BVetMed, MPH; Ohio State University Research Foundation
Amount: $5,000

Bladder Carcinogen Exposures in Pet Dogs

Bladder cancer is an aggressive cancer that affects ~ 20,000 dogs per year, and often leads to euthanasia. Certain breeds have a higher incidence of bladder cancer but genetic studies even in the highest risk breeds have been inconclusive and still indicate influence from environmental exposures. The investigators propose that specific household environmental chemical exposures contribute to the risk of bladder cancer in dogs.

In this study, they will measure urinary concentrations of five different chemicals that are known or suspected to be bladder carcinogens, in dogs with bladder cancer compared to unaffected dogs. The investigators will determine whether the presence of certain chemicals is associated with household exposures, based on owner questionnaires and household proximity to industrial sites. Finally, they will determine whether urinary chemical concentrations are linked to early DNA damage in the urinary cells of healthy dogs that do not have bladder cancer. The overall goal of this study is to provide veterinarians and dog owners with evidence-based bladder cancer prevention strategies.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 2780

RESEARCHERS

Lauren Trepanier, DVM, PhD; University of Wisconsin, Madison
Amount: $15,000

Transcriptional Profiling of Canine Soft Tissue Sarcoma

Soft tissue sarcomas account for 10-15% of all skin and subcutaneous cancers in dogs. Traditionally, biopsy and subsequent histology have been the primary means of diagnosing these cancers. The histology is assigned to one of three grades ranging from low (grade I), intermediate (grade II), and high (grade III). Histologic grade is currently the key criterion for guiding treatment and determining patient outcome. However, in human medicine and pathology, soft tissue sarcomas are diagnosed with a hybrid approach that involves both histologic features and genetic analysis of the tumor sample. This genetic analysis guides further treatment, aids in developing accurate follow-up information, and has been shown to have a positive effect on patient outcome and survival.

Despite how common soft tissue sarcomas are in the dog, current veterinary care still relies solely on the histologic grade, which is subjective at best, and does not incorporate genetic data into the diagnostic plan. This study will perform transcriptome analysis on 300 canine soft tissue sarcomas in order to establish the transcriptome profile of canine soft tissue sarcoma and correlate this transcriptome to patient follow-up. This will allow for the formation of a hybrid diagnostic approach that will provide more accurate information to inform the prognosis for dogs afflicted with soft tissue sarcoma.

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 2783

RESEARCHERS

Andrew Miller, DVM; Cornell University
Amount: $10,000

Examination of the Effects of Cannabidiol on Canine Neoplastic Cell Apoptosis/Autophagy and Potential for Chemotherapy Resistance or Sensitivity

Currently the use of cannabidiol (CBD) rich extracts for canine oncology patients is common, yet there is no data in canine oncology regarding the effects of CBD on canine cancer cells. Oncologists are wary of CBD use in their patients due to a lack of knowledge regarding the effects of CBD during chemotherapy.

Initial studies on cytotoxicity by the research team show that CBD has cytotoxic activity on a variety of canine cancer cell lines at modest concentrations in the laboratory. These effects cause apoptosis, or programmed cell death, within a very short time frame, suggesting a discrete mechanism.

The objective of this study is two-fold; 1) to determine if co-treatment of cancer cells with a common chemotherapeutic (doxorubicin) and CBD at varying concentrations affects chemotherapeutic cytotoxicity, and 2) to examine the molecular framework of the cell death response looking at the most commonly implicated pathways targeted in canine cancer treatment, including mechanisms of cell signaling and autophagy (removal of damaged cells).

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 02643-A

RESEARCHERS

Joesph J. Wakshlag, DVM, PhD; University of Florida
Amount: $2,500

Clinical Trial for Evaluation of Propranolol and Doxorubicin in the Treatment of Canine Hemangiosarcoma

Canine hemangiosarcoma is a largely incurable cancer in dogs, and treatment approaches to improve outcomes have remained relatively stagnant over the past few decades. Treatment remains a challenge partly because the cancer is frequently detected at an advanced stage and because these tumors are often resistant to chemotherapies. Recently published reports showed that propranolol, a drug used to treat heart disease in humans and dogs, substantially increased the survival time of human angiosarcoma patients when used in combination with standard of care treatments. Propranolol was also shown to sensitize hemangiosarcoma cells to doxorubicin, providing a more effective way to kill tumor cells. Because angiosarcoma is strikingly similar to canine hemangiosarcoma, this multi-institutional clinical trial has been designed to determine the efficacy of propranolol in dogs with hemangiosarcoma when used in combination with surgery and chemotherapy.

The main goal of the study is to establish whether propranolol in combination with doxorubicin following surgery improves outcomes for dogs when compared to the use of chemotherapy and surgery alone. The investigators will also evaluate the plasma concentrations of propranolol achieved during dosing to assess whether the levels of propranolol correlate to survival times. If successful, the findings from this approach will be rapidly conveyed to the veterinary community, and the guidelines provided to clinicians for the use of propranolol and doxorubicin for the treatment of canine hemangiosarcoma.

Co-investigators: David R. Brown, PhD, University of Minnesota; Michael O. Childress, DVM, MS, Purdue University; Jennifer Mahoney, DVM and Pascale Salah, DVM, University of Pennsylvania

Co-sponsored with the AKC Canine Health Foundation, Grant Number: 02534

RESEARCHERS

Erin Dickerson, PhD and Brian Husbands, DVM; University of Minnesota
Amount: $10,000

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

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