The researchers from the University of Utah and Columbia University medical schools found the virus in 27% of the 200 cancerous prostates they looked at. They say it was associated with more aggressive tumours and found in only 6% of non - cancerous prostates. The finding raises the prospect of one day producing a vaccine to protect against prostate cancer. This is the first report to link XMRV (Xenotropic murine leukaemia virus--related virus) to human cancers. XMRV is a retrovirus like HIV which works by inserting a copy of its own DNA into the chromosomes (染色体) of a cell they infect. When this occurs to a gene that regulates cell growth, it can disrupt the normal development of the cell. Dr Helen Rippon, Head of Research Management at The Prostate Cancer Charity, said the research was intriguing (吸引人的) but posed several key questions about the role the infection plays in prostate cancer. He said: " Around the world, extensive work is being undertaken to identify risk factors for prostate cancer which will enable treatments and tests for the disease to be refined. " "It is critically important to identify key triggers of prostate cancer to improve early detection of the disease in men with potentially life threatening prostate cancer. " XMRV is known to cause leukemia (白血病) and other tumours in animals. Dr Ila Singh, who led the study from the pathology department at the University of Utah, said: "We still don’t know that this virus causes cancer in people, but that is an important question we are going to investigate. " Dr Chris Parker, Cancer Research UK’ s prostate cancer expert at the Institute of Cancer Research said: "This exciting study raises the possibility that the virus might contribute to the development of some prostate cancers. " "In the future, if it turns out to he true, then we, could speculate about the possibility of vaccination to protect against prostate cancer, similar to the approach now used to prevent cervical cancer (子宫颈癌). \ What is XMRV
A．A kind of prostate cancer. B．A vaccine against prostate cancer. C．A kind of aggressive tumor. D．A virus found in some of cancerous prostates.