Researchers in Champaign, Illinois have discovered an altered myxoma virus that afflicts rabbits, infects and kills dog cancer cells but not healthy cells.  The virus doesn’t infect dogs or humans.  They also discovered that the deletion of a single gene improved the effectiveness of the myxoma virus anti-cancer therapy.

The study focused on spontaneously occurring cancers in dogs and was published in the American Journal of Veterinary Research. It’s part of broader research into treating cancers with viruses which offers several advantages over traditional treatment, according to University of Illinois veterinarian and pathobiology professor, Amy MacNeill, who led the new study.  Treatment using modified oncolytic viruses exploits cancer’s weakness – impaired anti-viral defenses.  This allows the virus to attack cancerous cells and produce an anti-cancer immune response without harming healthy cells.  Chemotherapy and radiation kills both cancerous and healthy cells, with the latter causing inflammation and pain in the patient.

“There was a study in cats where they removed the tumor surgically and then they put a viral therapy in the area where the tumor had been removed,” MacNeill said. The animals that received the viral therapy had significantly less regrowth of the cancer than those that weren’t exposed to the virus after surgery.

“Other studies have shown that once you’ve eliminated a cancer with an oncolytic virus, if you re-challenge that animal with the same cancer cells, they don’t develop tumors,” MacNeill said. Viral infection of the cancer cells appears to train the immune system to better recognize the cancer, she said.

While additional research could take several years, the team is enthusiastic about the possibility of helping both dogs and humans.

“We wanted to make sure that the dog cells were like the human cells because we want to use these viruses not only to cure dogs of cancer but also to use the dogs as better models for humans with cancer,” MacNeill said. “People are beginning to see the logic of this approach. These dogs have spontaneous tumors just like humans, they’re living in the same environment as humans, they’re exposed to the same carcinogens in the water if there are any and they sometimes even share our food.  This way we can test the therapy in dogs while at the same time treating them,” she said. “Other researchers can take our results and use them to develop therapies for human patients.”

We’re excited about the possibility of using naturally-occurring modified viruses to replace harsh cancer treatments for both dogs and humans.  We’ll keep you posted as science develops this amazing therapy.

More information

Oncolysis of Canine Tumor Cells by Myxoma Virus Lacking the Serp2 Gene, University of Illinois News Bureau.

Contact:  Diana Yates diya@illinois.edu 217-333-5802 or Amy MacNeill almac@illinois.edu 217-244-3950.  University of Illinois at Urbana-Champaign

Source: EurekAlert