AKC Canine Health Foundation - 37

Diffuse Large B Cell Lymphoma (DLBCL) of Golden
Retrievers Has a Unique DNA Methylation Signature That is
Highly Conserved
Jeff Bryan, DVM, MS, PhD, DACVIM(Oncology)
University of Missouri
BIOGRAPHY
Dr. Jeffrey Bryan earned his D.V.M. from the University of
California - Davis in 1993. He worked as an Associate
Veterinarian from 1993-1995 and served as Medical Director
from 1995-2002 of the Irving Street Veterinary Hospital in San
Francisco, CA. Bryan then completed a medical oncology residency, a Masters of Biomedical
Sciences, and a PhD in Pathobiology at the University of Missouri. He received certification by
the American College of Veterinary Internal Medicine in Oncology 2005. He is the Director of
the Tom and Betty Scott Endowed Program in Veterinary Oncology, the Director of PET Imaging
Center of the University of Missouri, Associate Department Chair for Research, and the
Associate Director of Comparative Oncology for Ellis Fischel Cancer Center. Dr. Bryan's
research focuses on comparative examination of cancers in companion animals to better
understand cancers in all species. His particular areas of interest are targeted imaging and
therapy, epigenetics, and immunotherapy of cancers. He directs the PET Imaging Center, which
seeks to develop novel PET imaging agents for cancer diagnosis, localization, and
prognostication. He studies DNA methylation of canine non-Hodgkin lymphoma. He studies
immunotherapy in companion dogs including investigating fetal microchimerism.
PRESENTATION ABSTRACT
Introduction: Recurrent DNA mutations have not well characterized high grade B cell
lymphomas (cBCL) in dogs. DNA methylation changes alter gene expression, offering other
potential cancer drivers. Unlike mutations, DNA hypermethylation changes may occur before
mutations and can be reversed, making them potential diagnostic markers of cancer that could
also be therapeutic targets. We used methylated island recovery seq (MIRA-seq) to define
genome-wide methylation profiles of cBCL in Golden Retrievers.
Methods: DNA was extracted from lymph node aspirates or biopsies from 23 Golden
Retrievers with naïve cBCL and from flow-sorted or bead-purified B cells (CD21+) and T cells
(CD4+ or CD8+) from 7 normal control dogs. Fragmented (~350 bp) DNA libraries were
enriched for methylated CG sequences using MIRA-seq on the Illumina HiSeq2500 as 1x100 bp
reads. The bioinformatic and pathway analysis is described in the published manuscript.
Results: Relative to normal lymphocytes, there were 13,982 hypermethylated and 4,467
hypomethylated differentially methylated regions (DMRs) in the cBCL samples. These
corresponded to protein-coding genes, lincRNAs, and miRNAs. DMRs were enriched in gene
control regions and not in intron or intergenic sequences, with nearly half in CpG islands. The
methylation signature of cBCL was distinct from normal lymphocytes. Hypermethylated
pathways included neurologic and cardiac as well as PI3k-Akt and Wnt/Hippo pathways. A 10
DMR signature reliably separated cBCL from normal lymphocytes. The hypermethylome of
cBCL shared characteristics with aggressive human DLBCL.
2023 National Parent Club Canine Health Conference
Presented by the AKC Canine Health Foundation and Nestlé Purina PetCare

AKC Canine Health Foundation

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