U A B C O M P R E H E N S I V E C A N C E R C E N T E R 11
COMMON GROUND Three years ago, Dr. Chambers began
the process of turning that insight into a full- fledged research program. Now, thanks to a grant from the UAB Comprehensive Cancer Center, she and her colleagues have ana- lyzed more than 50 naturally occurring brain tumors in pet dogs as part of the Alabama Comparative Oncology Network.
Previous research has shown that canine brain tumors known as gliomas spring from chromosomal mutations that may also be the source of glioblastoma multiforme, a malig- nant human brain tumor with a low survival rate. The canine and human tumors also occur at similar rates in both populations, and they share common patterns of progres- sion and response to treatment.
Using genotyping, Dr. Chambers s group analyzed gene deletions and amplifications, looking for similarities between the dog tumors and comparable human tumors. We have identified genes involved in several cancer- related signaling pathways, Dr. Chambers says. It s a very exciting time for cancer researchers and a very promising time for cancer patients.
Dr. Chambers s group is now collecting information from tumors found in pet dogs to determine the reliability of certain breeds of canines as animal models for human dis- eases, she says. Brachycephalic (short-nosed) breeds such as boxers tend to develop benign tumors, while dolichocephalic (long-nosed) breeds such as golden retrievers develop malignant tumors, Dr. Chambers explains.
L ABOR OF LOVE The project represents a homecoming
of sorts for Dr. Chambers, who worked as a veterinarian for five years in Birmingham before deciding to enroll in UAB s School of
Medicine in the early 1990s. Her husband, Jimmy Milton, D.V.M., is a veterinary sur- geon in Birmingham. The most interesting cases to me as a veterinarian were the neuro- surgical cases I saw, Dr. Chambers recalls. When I was still working as a veterinar- ian, Dr. Garber Galbraith and Dr. Richard
Morawetz, then head of neurosurgery at UAB, invited me to come by and join rounds with their doctors, and I continued to do that while I was in medical school.
The combination of veterinary and human medicine makes Dr. Chambers a rare breed. There s probably one person every few years who pursues both M.D. and D.V.M. degrees in the United States, she says. I ve only met two myself.
During medical school, Dr. Chambers worked as a research assistant studying (human) brain tumors with Yancey Gillespie, Ph.D., and James Markert, M.D., M.P.H., now director of neurosurgery at UAB. One of my first publications that came from that work addressed viral therapy of brain tumors, Dr. Chambers says. That s what initially sparked my interest, and it was a natural connection to look back at dogs.
MUTUAL BENEFIT S Although Dr. Chambers s group is
called the Alabama Comparative Oncology Network, it already has expanded to include
participants from Mississippi, Georgia, Florida, and Tennessee; her goal is to build a national and even international catalog of outcomes data. Canine and human tumors are so similar that it would be ideal to cor- relate results from both species for the data- base, she says. Collecting extensive clinical
data from companion dogs with naturally occurring brain tumors may allow us to cata- log tumor signatures more quickly, expand- ing the knowledge base for human cancer and identifying potential targets for new drugs, Dr. Chambers says. My goal is to establish and confirm the genomic similarities among humans and pet dogs so that they might share treatments that come out of this and other research the sooner, the better.
Research candidates are currently drawn from pets who have been brought to veteri- nary hospitals including those at Auburn University and Mississippi State University for treatment. After the dogs tumors have been surgically removed, owners can elect to have clinicians treat the dogs using can- cer therapies that have already been tested in humans. The owners pay for the costs of treatment. Including pets with naturally occurring brain tumors in novel treatments being used in humans will increase the amount of outcomes data while offering these misfortunate animals compassionate treat- ment, Dr. Chambers says.
My goal is to establish and confirm the genomic similarities among humans and pet dogs so that they might share treatments that come out of this and other research. Renee Chambers, D.V.M., M.D.