Massey vet probes cat cancer link

A Massey researcher is a step closer to developing a vaccine for a common form of skin cancer in cats.

Dr John Munday, a veterinary pathologist at the Institute of Veterinary, Animal and Biomedical Sciences, is researching a possible link between papillomaviruses and cancer in cats.

Papillomaviruses are thought to cause around 5 per cent of cancers in people, including cervical cancer in women and a proportion of cancers of the mouth. In people, vaccines have recently been introduced to prevent papillomaviral infection and reduce the rate of cancer development.

“We’re looking at a skin cancer that is common in cats, called squamous cell carcinoma,” Dr Munday says. “It is the most common skin cancer in cats, and is a frequent reason that a cat may be put down.”

Dr Munday is undertaking a survey to see if a link exists between squamous cell carcinomas in cats and papillomavirus infection. “At this stage we’re surveying diagnostic samples that have been taken from cats with this type of cancer. We then determine whether papillomavirus DNA is present within the cancer. Detecting a higher rate of infection in the cancers than in other non-cancer skin samples could help prove the link between papillomaviral infection and cancer development.”

In addition, Dr Munday is evaluating diagnostic samples of cancers for changes in protein expression. “In human oral cancers, researchers can look for a specific change in a protein which regulates whether or not a cell will multiply,” Dr Munday says. “When a papillomavirus infects a cell and turns it cancerous, it interferes with the way the body controls that cell. In essence, the cancer cell becomes independent of the body.

“The way the papillomavirus causes cancer also increases the expression of the p16 protein. This action of some papillomaviruses is so consistent that increased p16 expression is considered ’a fingerprint’ of papillomavirus infection in humans. So we’re looking to see if it’s the same in cats.”

Research carried out so far has been promising. “At this stage we have established that a papillomavirus is significantly associated with cancer, the next step is to definitively prove this papillomavirus causes the cancer,” Dr Munday says. If a causal link is proven, the development of a vaccine to protect against papillomavirus infection should be able to reduce the development of this common, often fatal, cancer of cats.