In the Oncology Laboratory
Center for Companion Animal Health, UC Davis,
The new oncology laboratory will foster collaborative
research studies, and also provide space for residents
and veterinary students to participate directly in bench
Medical oncologist Dr. Cheryl London, who specializes
in the molecular biology of cancer, is co-leader of the
Tumor Biology in Animals Program, part of the NCI Cancer
Center Support Grant. One of the purposes of this
program is to study the biologic behavior and treatment
of spontaneous tumors in dogs and cats, as these tumors
more closely mimic human cancer than do mouse tumors.
Dr. London has several clinical trials underway for a
variety of different cancers in dogs including mast cell
tumors and sarcomas. One research project in her lab
being conducted by Medical Oncology Resident Dr. Suzanne
Shelly is focused on identifying a potential new
treatment for canine melanoma.
Malignant melanoma in the dog is very resistant to
standard therapies says Dr. London. In dogs, it develops
in the oral cavity, spreads early on, and usually can’t
be cured. In humans, it develops in the skin (from sun
exposure). The cause is unknown, but the biology is the
same. Melanoma in the dog makes a good biological model
for the disease in humans.
Developing a Therapy for Canine Lymphoma
Dr. Steven Suter, lecturer in medical oncology and
researcher in Dr. London’s laboratory, is working on a
novel therapy for canine lymphoma.
Canine distemper virus has been shown to kill
lymphoma cells in vitro. Canine lymphoma cell cultures
are exposed to a canine distemper virus that carries a
fluorescent marker. When viewed with a fluorescence
microscope, infected cells glow green.
Dr. Suter is now working to demonstrate a similar result
in dogs with lymphoma by introducing the distemper virus
to the lymph nodes by internodal injection. The ultimate
objective is to develop a therapy administered
intravenously to lymphoma patients.
This CCAH research is being done in partnership with
the Mayo Clinic in Rochester, Minnesota.
Suter introduces canine distemper virus to a
canine lymphoma cell line, which kills the
lymphoma cells in culture.
(infected) canine lymphoma cells begin to
Dr. Suzanne Shelley, resident in medical oncology, is
looking for mutations in the cloned canine gene B-RAF,
which is also a good model for human melanoma. A private
company is working with the lab to develop inhibitors
that will target mutant B-RAF.
Dr. Michael Kent, who has just joined the UC Davis
faculty as a radiation oncologist, is working on the
molecular mechanisms of resistance to radiation in dogs
with melanoma and ways to overcome resistance. Malignant
melanoma is resistant to radiation therapy in both
humans and dogs.
"I am working to find the causes of radiation
resistance in canine melanomas by looking at gene
expression in cell lines made from some of our clinical
patients,” says Dr. Kent. “We are also looking at the
effects of irradiation on gene expression in the cell
lines, and ways to block gene expression in resistant
cells, so the melanoma cells will become more sensitive
|Right: Dr. Michael Kent
cultures cell lines from dogs with oral (mouth)
Above: (right) petri dish with cell colonies and
(left) close-up view showing stained “resistant”
cells that grew colonies after being irradiated.
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