Friday, February 24, 2006
We're gonna spray for prostate cancer so unzip—You read it here first!
Here's an intriguing one: researchers have discovered a virus in some cancerous prostates. They make it clear they have established no link between the virus and the disease, but it's enough to make other scientists go "hmmm." The work, done at the University of California, San Francisco, and the Cleveland Clinic, found a virus in cancerous prostates of men with a certain genetic defect. Until now, that virus, XMRV, was found only in mice. The form of prostate cancer involved is familial, which accounts for only about 9% of all prostate cancers.
The idea that some cancers have a viral cause, or that viruses at least play a part in cancer, is well-established. Some liver and cervical cancers are caused by viruses and there may be a viral component—along with environment and genetics—in breast, stomach and other forms of cancer. That latter may be the case here. And, the idea that a virus may play a part in prostate cancer, isn’t new. In 2004, researchers at the University of Michigan found DNA from the BK virus in prostate cancer cells. No one knows what that means either.
The virus, related to retroviruses known as xenotropic murine leukemia, is somehow transmitted by the genes and has been passed on for thousands of years. Xeotropic means it can pass from species to species, but while there are examples of it passing from mice to other animals, there is no record of it doing so to humans. Testing prostate cells of 20 patients who had two copies of the mutated genes turned up 8 of them with the virus. Since the gene is part of the immune system, men with the mutated gene make less of an enzyme that helps kill viruses. This virus got through. It's not likely the virus came from mice. And, since it was found in just one of 66 other patients, presumably without the genetic mutation, there might be a link between the virus and genetics in causing cancer.
Another puzzle is that the virus is not found in the cancer cells, but in the stroma, the surrounding, non-cancerous tissue. Nor is every cell involved.
The research was reported Thursday at a meeting of the American Society of Clinical Oncology in San Francisco.
Oh, and while we're at it, earlier this month the folks at UCSF released a study showing that the folk remedy saw palmetto had absolutely no effect on enlarged prostates. As the owner of one, I am displeased.