Posted on 08/10/2006 3:30:24 PM PDT by blam
Riddle of infectious dog cancer solved
15:39 10 August 2006
NewScientist.com news service
Andy Coghlan
A mysterious contagious cancer which plagues dogs throughout the world may be the first truly transmittable cancer known, a new study suggests.
The cancer cells themselves move directly from dog to dog, acting “parasitically” on each infected animal, the researchers say.
Canine transmissible venereal tumour (CTVT) spreads between dogs through sex or other forms of contact, such as licking and biting, they believe.
The same cancer appears to infect dogs throughout the world and probably originated from a cancer in a single wolf, or a dog closely related to a wolf, which lived between 250 and 1000 years ago, the researchers say.
Direct descendents
Previously, viruses were suspected of spreading CTVT in the same way that the human papilloma virus – found in genital warts – spreads cervical cancer to women through sex.
But a new genetic analysis shows that the dog cancer cells are direct descendents of tumour cells from the long-dead animal in which the disease originated.
“The cancer escaped its original body and became a parasite transmitted from dog to bitch and bitch to dog until it had colonised all over the world,” says lead researcher Robin Weiss at University College London in the UK.
“The idea that this is caused by transfer of the cancer cells themselves, not a cancer-causing virus, has been around for 30 years,” says Weiss. “Now we’ve proved it through forensic DNA analysis.”
Weiss said that the discovery makes the cancer, otherwise known as Sticker’s sarcoma, “the oldest cancer known to science”, and possibly the world’s longest-lived colony of cloned mammalian cells.
Mangy strays
Weiss and his colleagues made the discovery after analysing samples of blood from 16 unrelated dogs from five different continents...
(Excerpt) Read more at newscientist.com ...
Great. How long before this spreads to humans - and you know who you are.
pong
This would be the fifth known type of infectious agent after parasites, bacteria, viruses and prions. Individual cells from another animal and cancerous at that? weird.
Maybe not. A transmittable form of cancer had already been reported in the past couple of years in Tasmanian devils.
Thanks so much for posting this.
dog aids?
They're supposed to ping you if you are referenced in a post. :-)
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