Researchers from the University of Utah and Columbia University medical schools found the XMRV (Xenotropic murine leukaemia virus-related virus) in 27% of the 200 cancerous prostates they looked at. Moreover it was associated with more aggressive tumours and found in only 6% of non-cancerous prostates. This becomes evan more suspicious considering that XMRV is known to cause leukaemia and other tumours in animals.
XMRV is a retrovirus and therefore inserts a copy of its own DNA into the chromosomes of a cell it infects. If this occurs next to a gene that regulates cell growth it can disrupt the normal development of the cell, possibly leading to unregulated cell growth and loss of cell Apoptosis resulting in a tumour. The virus has an androgen response element meaning its growth is stimulated by the presence of testosterone and possibly Oestrogen. If this can be proved then XMRV could have a role in causing other cancers.
If it turns out that XMRV does cause cancer, it may be possible to create a vaccine against the virus and thus greatly reduce the occurrence of certain cancers. However, this remains a theory in early stages of research, and the relationship between the presence of the virus and prostate cancer could just be a coincidental correlation.
We can only hope....