From The New York Times:
A team of scientists in Cleveland and San Francisco said yesterday that they had discovered a new virus in patients who had a rare form of prostate cancer. The patients all had a particular genetic mutation. The virus, called XMRV, could prove to be harmless. Other viruses cause certain cancers of the liver and the cervix. Prostate cancer causes 30,000 deaths a year in this country, making it the second-leading cause of cancer deaths in men, behind lung cancer.
The discovery came from a collaboration between scientists in different fields: genetics in Cleveland and virology in San Francisco. About 10 years ago, in Cleveland, Dr. Robert H. Silverman discovered a gene called RNAsel that is present in all people and that helps fight viruses. But men with the mutation are at greater risk for prostate cancer. Two years ago, in San Francisco, Dr. Don Ganem and Dr. Joe DeRisi created a virus chip with the goal of discovering unknown viruses that might cause human disease. The scientists began their collaboration after Dr. Silverman read about the virus chip. Using the chip, the researchers in California tested tissue removed at surgery from 86 prostate cancer patients. Among the 20 prostate tumor samples from men with mutations in both copies of the RNAsel viral defense gene, eight — or 40 percent — had the virus. This compared with only 1 of 66 (1.5 percent) tumors from men with at least one normal copy of the gene. Tests showed that the viruses in the patients were the same, even though there was no relationship between any of the patients.