Publications by authors named "Dawn Duval"

A 7-year-old female spayed Bernese Mountain dog was presented for evaluation of hematuria. Incidentally, a right stifle sarcoma was diagnosed via cytology, which raised concern for histiocytic sarcoma (given the patient's signalment) versus another joint-associated sarcoma. Histopathology and immunohistochemistry revealed a CD18-negative, non-histiocytic origin cell population.

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Pet dogs develop spontaneous cancers at a rate estimated to be five times higher than that of humans, providing a unique opportunity to study disease biology and evaluate novel therapeutic strategies in a model system that possesses an intact immune system and mirrors key aspects of human cancer biology. Despite decades of interest, effective utilization of pet dog cancers has been hindered by a limited repertoire of necessary cellular and molecular reagents for both in vitro and in vivo studies, as well as a dearth of information regarding the genomic landscape of these cancers. Recently, many of these critical gaps have been addressed through the generation of a highly annotated canine reference genome, the creation of several tools necessary for multi-omic analysis of canine tumours, and the development of a centralized repository for key genomic and associated clinical information from canine cancer patients, the Integrated Canine Data Commons.

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Pharmacologic inhibition of autophagy can be achieved using lysosomotropic agents such as hydroxychloroquine (HCQ) that interfere with fusion of the autophagosome to the lysosome thus preventing completion of the recycling process. The goal of the present study is to determine the sensitivity of eight canine (cOSA) and four human (hOSA) osteosarcoma tumour cell lines to antiproliferative and cytotoxic effects of lysosomal autophagy inhibitors, and to compare these results to the autophagy-dependence measured using a CRISPR/Cas9 live-cell imaging assay in OSA and other tumour cell lines. Antiproliferative and cytotoxic response to HCQ and Lys05 was determined using live cell imaging and YOYO-1 staining.

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Soft tissue sarcomas (STS) are a heterogenous group of mesenchymal tumors representing over 50 distinct types with overlapping histological features and non-specific anatomical locations. Currently, localized sarcomas are treated with surgery + / -  radiation in both humans and dogs with few molecularly targeted therapeutic options. However, to improve precision-based cancer therapy through trials in pet dogs with naturally occurring STS tumors, knowledge of genomic profiling and molecular drivers in both species is essential.

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Canine soft tissue sarcomas (STS) are a heterogenous group of malignant tumors arising from mesenchymal cells of soft tissues. This simplified collective of tumors most commonly arise from subcutaneous tissues, are treated similar clinically, and conventionally exclude other sarcomas with more definitive anatomical, histological, or biological features. Histologically, canine STS sub-types are difficult to discern at the light microscopic level due to their overlapping features.

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Osteosarcoma affects about 2.8% of dogs with cancer, with a one-year survival rate of approximately 45%. The purpose of this study was to characterize mutation and expression profiles of osteosarcoma and its association with outcome in dogs.

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Background: This study is a prospective clinical trial in dogs with osteosarcoma testing a gene expression model (GEM) predicting the chemosensitivity of tumors to carboplatin (CARBO) or doxorubicin (DOX) developed using the COXEN method.

Patients And Methods: Sixty dogs with appendicular osteosarcoma were enrolled in this trial. RNA isolation and gene expression profiling were conducted with 2 biopsies for 54/63 screened tumors, and with a single biopsy for 9 tumors.

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Transitional cell carcinoma (TCC), also known as urothelial carcinoma, is the most common bladder cancer in humans and dogs. Approximately one-quarter of human TCCs are muscle-invasive and associated with a high risk of death from metastasis. Canine TCC (cTCC) tumours are typically high-grade and muscle-invasive.

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MicroRNAs (miRNA) are small non-coding RNA molecules involved in post-transcriptional gene regulation. Deregulation of miRNA expression occurs in cancer, and miRNA expression profiles have been associated with diagnosis and prognosis in many cancers. Osteosarcoma (OS), an aggressive primary tumor of bone, affects ~10,000 dogs each year.

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Periostin is a matricellular protein important in regulating bone, tooth, and cardiac development. In pathologic conditions, periostin drives allergic and fibrotic inflammatory diseases and is also overexpressed in certain cancers. Periostin signaling in tumors has been shown to promote angiogenesis, metastasis, and cancer stem cell survival in rodent models, and its overexpression is associated with poor prognosis in human glioblastoma.

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Background: The availability and generation of large amounts of genomic data has led to the development of a new paradigm in cancer treatment emphasizing a precision approach at the molecular and genomic level. Statistical modeling techniques aimed at leveraging broad scale in vitro, in vivo, and clinical data for precision drug treatment has become an active area of research. As a rapidly developing discipline at the crossroads of medicine, computer science, and mathematics, techniques ranging from accepted to those on the cutting edge of artificial intelligence have been utilized.

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Cancer cell culture has been a backbone in cancer research, in which analysis of human cell line mutational profiles often correlates with oncogene addiction and drug sensitivity. We have conducted whole-exome sequence analyses on 33 canine cancer cell lines from 10 cancer types to identify somatic variants that contribute to pathogenesis and therapeutic sensitivity. A total of 66,344 somatic variants were identified.

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Transitional cell carcinoma (TCC) of the bladder comprises 2% of diagnosed canine cancers. TCC tumors are generally inoperable and unresponsive to traditional chemotherapy, indicating a need for more effective therapies. BRAF, a kinase in the mitogen-activated protein kinase (MAPK) pathway, is mutated in 70% of canine TCCs.

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Background: "Readability" of consent forms is vital to the informed consent process. The average human hospital consent form is written at a 10th grade reading level, whereas the average American adult reads at an 8th grade level. Limited information currently exists regarding the readability of veterinary general medical or clinical research consent forms.

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Pet dogs are becoming increasingly recognized as a population with the potential to inform medical research through their treatment for a variety of maladies by veterinary health professionals. This is the basis of the One Health initiative, supporting the idea of collaboration between human and animal health researchers and clinicians to study spontaneous disease processes and treatment in animals to inform human health. Cancer is a major health burden in pet dogs, accounting for approximately 30% of deaths across breeds.

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Background: Genomics-based predictors of drug response have the potential to improve outcomes associated with cancer therapy. Osteosarcoma (OS), the most common primary bone cancer in dogs, is commonly treated with adjuvant doxorubicin or carboplatin following amputation of the affected limb. We evaluated the use of gene-expression based models built in an intra- or interspecies manner to predict chemosensitivity and treatment outcome in canine OS.

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Gastrointestinal stromal tumors (GISTs) and leiomyosarcomas are histologically similar primary neoplasms commonly occurring in the gastrointestinal tract of dogs and humans. Immunohistochemical staining (IHC) is needed to differentiate between these 2 entities and positive reactivity for KIT (cluster of differentiation [CD]117) is regarded as the gold standard for diagnosis of canine GIST. Studies estimate 5-10% of human GISTs stain negative or only weakly positive for KIT and have identified DOG1 (discovered on gastrointestinal stromal tumors protein 1) as a highly sensitive and specific marker for human GISTs.

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Background: Mast cell tumors (MCTs) are the most common skin tumors in dogs and exhibit variable biologic behavior. Mutations in the c-kit proto-oncogene are associated with the tumorigenesis of MCTs, resulting in growth factor-independent and constitutive phosphorylation of the KIT receptor tyrosine kinase (RTK). Toceranib (TOC) phosphate (Palladia®) is a KIT RTK inhibitor that has biological activity against MCTs.

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The purpose of this study was to explore the role of transcription factor Ets1 in estrogen receptor α (ERα)-positive breast cancer progression. We expressed human Ets1 or empty vector in four human ERα-positive breast cancer cell lines and observed increased colony formation. Further examination of cellular responses in stable Ets1-expressing MCF7 clones displayed increased proliferation, migration, and invasion.

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Background: Hairy and enhancer of split 1 (HES1), a basic helix-loop-helix transcriptional repressor, is a downstream target of Notch signaling. Notch signaling and HES1 expression have been linked to growth and survival in a variety of human cancer types and have been associated with increased metastasis and invasiveness in human osteosarcoma cell lines. Osteosarcoma (OSA) is an aggressive cancer demonstrating both high metastatic rate and chemotherapeutic resistance.

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Cell line cross-contamination as well as genetic drift during passaging have been acknowledged as widespread problems since the 1960s. Improper cell line identification can invalidate results and, if not discovered, pollute the scientific community's body of knowledge with regard to cancer cell lines, their gene expression, and their drug susceptibilities. Despite the obvious need, validation of cell line identity is not yet widely required, and the problem persists.

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Osteosarcoma (OS) is the most commonly diagnosed malignant bone tumor in humans and dogs, characterized in both species by extremely complex karyotypes exhibiting high frequencies of genomic imbalance. Evaluation of genomic signatures in human OS using array comparative genomic hybridization (aCGH) has assisted in uncovering genetic mechanisms that result in disease phenotype. Previous low-resolution (10-20 Mb) aCGH analysis of canine OS identified a wide range of recurrent DNA copy number aberrations, indicating extensive genomic instability.

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Background: Osteosarcoma (OSA) spontaneously arises in the appendicular skeleton of large breed dogs and shares many physiological and molecular biological characteristics with human OSA. The standard treatment for OSA in both species is amputation or limb-sparing surgery, followed by chemotherapy. Unfortunately, OSA is an aggressive cancer with a high metastatic rate.

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