AUG 05, 2019 7:46 PM PDT

A Canine Cancer That Began to Spread From One Dog About 6,000 Years Ago

WRITTEN BY: Carmen Leitch

Dogs can get different kinds of cancers, including one that is transmitted by live cancer cells, which spreads through sexual contact, called canine transmissible venereal tumor (CTVT). Researchers have now traced this cancer back to a single dog, a founder that lived sometime between 4,000 and 8,500 years ago. The findings have been reported in Science.

Artist's impression of the 'founder dog' that first gave rise to CTVT. This dog's phenotypic traits were interpreted from the genetic variation found in the DNA of the cancer that it spawned. / Credit: Emma Werner

In this work, scientist Adrien Baez-Ortega of the University of Cambridge and colleagues sequenced tumors from 546 dogs around the world, including two dogs of different breeds from Brazil and Australia that both had CTVT. Their tumor cell genomes had almost two million mutations in common, which aren’t found in normal canine DNA. The scientists found that the CTVT genome has remained very stable over time, and contains variations in its sequence that aren’t in normal canine DNA. This showed that CTVT doesn’t develop in dogs sometimes; it arose one time and has spread ever since, from one dog to another.

The work also suggests that CTVT doesn’t progress much over time. Tumors seem to grow to an optimum state and then stabilize, whichi is unusual because cancerous tumors often pick up new mutations as the cells proliferate. Some of those mutations might not have any impact, while others could be harmful to the tumor. But some mutations can increase growth and resistance to drug treatments.

This work could help researchers learn more about human cancers that grow slowly, and how to limit tumor growth when it doesn’t pose a serious health threat.

"Cancers evolve, and our strategies for managing cancer need to take that into account," commented Carlo Maley, who wrote about this research with Darryl Shibata in Science. In the future, we hope to maintain long-term control over these evolving tumors. CTVT is fascinating because it shows us how cancers might evolve over the long term."

"Most cancers can only evolve for a few decades before they die with their host," Maley added. "CTVT is an incredible natural experiment, which showed us that it doesn't take much for a cancer to reach an optimal state. It is amazing that it did not discover additional adaptations over thousands of years, even as it infected all different breeds of dogs in all different environments around the world."

Learn more about CTVT from the video above.

In other research on unrelated canine cancers, researchers are testing a new vaccine in a trial. Learn more from the video below.

 

Source: AAAS/Eurekalert! via Arizona State University, Science

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
MAY 07, 2021
Space & Astronomy
Did Scientists Just Find Mushrooms on Mars?
MAY 07, 2021
Did Scientists Just Find Mushrooms on Mars?
While experts agree that most life on Earth would not be able to survive on Mars, NASA researchers have previously sugge ...
MAY 14, 2021
Coronavirus
How COVID-19 Patients Lose Their Sense of Smell
MAY 14, 2021
How COVID-19 Patients Lose Their Sense of Smell
The loss of the sense of smell is a well-known symptom of COVID-19, and was common even in people that did not have many ...
JUN 01, 2021
Microbiology
A Closer Look at a Potential Bioweapon
JUN 01, 2021
A Closer Look at a Potential Bioweapon
Francisella tularensis is a naturally occurring bacterium found throughout the Northern Hemisphere that is extremely vir ...
JUN 04, 2021
Cell & Molecular Biology
Even When They're Outside the Brain, Infections Worsen Alzheimer's
JUN 04, 2021
Even When They're Outside the Brain, Infections Worsen Alzheimer's
It's thought that inflammation is closely connected to cognitive decline, and neuroinflammation plays a role role in the ...
JUN 14, 2021
Microbiology
Researchers Identify a Novel, Beneficial Bacterium
JUN 14, 2021
Researchers Identify a Novel, Beneficial Bacterium
Since researchers were able to use genetic technologies to reveal how important the gut microbiome is to human health, t ...
JUN 16, 2021
Microbiology
DNA - It's What's for Dinner (For Some Bacteria)
JUN 16, 2021
DNA - It's What's for Dinner (For Some Bacteria)
There may be a trillion species of microbes on the planet, so clearly there's still a lot we don't know about these micr ...
Loading Comments...