Studying the similarities and differences between canine and human cancer gives veterinarian Jaime Modiano insights to help fight the disease.
Cause for paws
By Mary Hoff
February 28, 2008
Jaime Modiano has learned a lot of things from dogs: what sheer, unadulterated exuberance looks like; how much fun is wrapped up in a simple tennis ball; why it's a bad idea to leave the room when there's food on the table.
The one thing he'd really like to learn from them? How to conquer cancer.
Modiano joined the University last July as director of the Veterinary Medical Center's Animal Cancer Center and Alvin S. and June Perlman Endowed Chair in Animal Oncology. He studies naturally occurring cancer in dogs in hopes of improving cancer prevention, treatment, and cures for pets and people alike. Modiano's research focuses on cancer at the cellular level, learning how good cells go bad-and what can be done about it.
One out of three dogs will get cancer, and cancer kills more dogs than any other disease-so reducing the toll of the disease is important to veterinarians. But what we learn about canine cancer is valuable for learning about human cancers, too, Modiano says. For one thing, dogs are more similar to humans than most experimental animals. And they live in our homes and play in our yards, "so there's a certain sense of a sentinel--if they get something, maybe we will, too."
A lifetime zips by faster for dogs than people, so canine cancer progresses more quickly in dogs than people. Thus development of the disease can be studied in years rather than decades, and therapies can often be evaluated in a matter of months.
Perhaps most important from Modiano's perspective is the genetic angle. Centuries of trait selection and superbly documented pedigrees provide a treasure trove of information that can be used to delve for links between genes and both susceptibility to cancer and response to treatment.
"Breeds give us information we couldn't get in humans," Modiano says. That genetic connection is providing Modiano with valuable insights into canine cancers. He has shown that different kinds of dogs tend to develop different kinds of lymphoma. He's developing a blood test to diagnose cancer of the blood vessels and melanoma before it can be detected clinically.
He is evaluating an experimental gene therapy for bone cancer in dogs that not only kills tumor cells, but also activates the immune system so it can also search and destroy any remnants lurking in the body. The results are promising, and he anticipates eventual clinical trials in humans.
This just in...
U vet Jaime Modiano and Matthew Breen of North Carolina State University's Center for Comparative Medicine and Translational Research, have recently found that humans and dogs share the same genetic basis for certain types of cancer.
According to the researchers, the genetic changes that occur in dogs diagnosed with certain cancers of the blood and bone marrow, including chronic myelogenous leukemia, Burkitt's lymphoma, and chronic lymphocytic leukemia, are virtually identical to genetic abnormalities in humans diagnosed with the same cancers. (The human genome has 46 chromosomes and the dog genome contains 78 chromosomes.)
"The implication of this finding is that cancer may be the consequence of generations of genetic evolution that has occurred similarly in dogs and humans," says Modiano. "This means that to some degree, cancer may be inevitable in some humans and dogs just because of the way our genomes have developed since the separation from a common ancestor."
Modiano and Breen will now use grants from the National Cancer Institute to start pinpointing risk factors for cancer in various breeds of dogs. The findings are published in the current, special edition of the journal Chromosome Research.
Although his appointment is in the College of Veterinary Medicine in St. Paul, Modiano's lab is in the Cancer Center Research Building in Minneapolis. The interdisciplinary center puts him shoulder to shoulder with colleagues in the Medical School, College of Pharmacy, and School of Public Health-fertile ground for innovation. He recently began working with Carole Lange in the Medical School Departments of Medicine and Pharmacology, exploring how progesterone influences mammary cancer in cats--with potential application to breast cancer in humans. And he's eager for other collaborations with human-cancer colleagues in areas such as genetics of cancer and targeted drug therapies. Modiano makes no bones about doing cancer research for dogs' sake. But he appreciates that it can inform human cancer research. "A big part of our mission as veterinarians is to improve the health and well-being of companion animals," he says, "so we're taking advantage of this wealth of resources at the Cancer Center to try and do that. At the same time, by learning from animals, we learn stuff that hopefully will translate to people as well."
And, he adds, he and his veterinary colleagues gain much from human cancer research that helps them help dogs, too.
"It's not just what we bring to the table, but also what we gain in terms of coming up with information that allows us to treat and work with our patients," he says. "It's a bridge of collaboration."