Tag Archives: tumours in dogs

Treating canine cancer with nanotechnology

An 11-year-old Labradoodle named Grayton  is the first patient at the Virginia-Maryland College of Veterinary Medicine in a new clinical trial that is testing the use of gold nanoparticles and a targeted laser treatment for solid tumors in dogs and cats.

Grayton is suffering from a return of nasal adenocarcinoma, a cancer of the nasal passages that typically has a short life expectancy.  (Grayton’s tumor was originally treated with high dose radiation which extended his life by three years.)

Dr. Shawna Klahn, assistant professor of oncology in the Department of Small Animal Clinical Sciences, performs a checkup on Grayton four weeks after his experimental cancer treatment involving gold nanoparticles and a targeted laser therapy. (photo courtesy of Virginia Tech News)

Dr. Shawna Klahn, assistant professor of oncology in the Department of Small Animal Clinical Sciences, performs a checkup on Grayton four weeks after his experimental cancer treatment involving gold nanoparticles and a targeted laser therapy. (photo courtesy of Virginia Tech News)

“This (nanotechnology) treatment involves two phases,” Dr. Nick Dervisis, assistant professor of oncology in the Department of Small Animal Clinical Sciences, said. “First, we infuse the patient with the gold nanoparticles. Although the nanoparticles distribute throughout the body, they tend to concentrate around blood vessels associated with tumors. Within 36 hours, they have cleared the bloodstream except for tumors. The gold nanoparticles are small enough to circulate freely in the bloodstream and become temporarily captured within the incomplete blood vessel walls common in solid tumors. Then, we use a non-ablative laser on the patient.”

Dervisis explained that a non-ablative laser is not strong enough to harm the skin or normal tissue, but “it does cause the remaining nanoparticles to absorb the laser energy and convert it into heat so that they damage the tumor cells.”

Like all clinical trials, the study involves many unknowns, including the treatment’s usefulness and effectiveness. One month after the AuroLase treatment, the nosebleeds that initially brought Grayton back to the Veterinary Teaching Hospital had stopped and Grayton has no other side effects.

Grayton’s owners report that he recently enjoyed the family’s summer vacation at the beach.

Grayton may be the first companion animal in the study at the veterinary college, but he certainly won’t be the last. Dervisis is continuing to enroll patients in the study and is seeking dogs and cats of a certain size with solid tumors who have not recently received radiation therapy or chemotherapy. For more information about the trial and eligibility requirements, owners should visit the Veterinary Clinical Research Office website.

Source:  Media release, Virginia Tech News

A dog cancer that is 11,000 years old

Scientists have sequenced the genome of the world’s oldest continuously surviving cancer, a transmissible genital cancer that affects dogs.

Credit: © Melinda Nagy / Fotolia

Credit: © Melinda Nagy / Fotolia

The cancer, which causes grotesque genital tumours in dogs around the world, first arose in a single dog that lived about 11,000 years ago. The cancer survived after the death of this dog by the transfer of its cancer cells to other dogs during mating.

Analysis of the genetic variants in the genome revealed that the dog may have resembled an Alaskan Malamute or Husky. It probably had a short, straight coat that was coloured either grey/brown or black. Its genetic sequence could not determine if this dog was a male or a female, but did indicate that it was a relatively inbred individual.

The genome has over 2 million mutations; the research team used one type of mutation, known to accumulate steadily over time, as a ‘molecular clock.’  This led to the estimate that the cancer first arose 11,000 years ago.

“The genome of this remarkable long-lived cancer has demonstrated that, given the right conditions, cancers can continue to survive for more than 10,000 years despite the accumulation of millions of mutations”, says Dr Elizabeth Murchison, first author from the Wellcome Trust Sanger Institute and the University of Cambridge.

Transmissible cancers are very rare in nature.  Apart from the dog transmissible cancer, the only other known naturally occurring transmissible cancer is an aggressive transmissible facial cancer in Tasmanian devils that is spread by biting.

Source:  Wellcome Trust media statement