[Note: See also a commentary on these findings published April
1, by Scientific American. See also a Salt Lake news video clip
of lead investigator Dr. Ila Singh.] Background: Xenotropic
murine leukemia-related retrovirus (XMRV) is a recently
discovered retrovirus that has been linked to human prostate
cancer and chronic fatigue syndrome (CFS). Both diseases affect
a large fraction of the world population, with prostate cancer
affecting one in six men, and CFS affecting an estimated 0.4 to
1% of the population. Principal Findings: Forty-five compounds,
including twenty-eight drugs approved for use in humans, were
evaluated against XMRV replication in vitro. • We found that the
retroviral integrase inhibitor, raltegravir, was potent and
selective against XMRV at submicromolar concentrations, in MCF-7
and LNCaP cells, a breast cancer and prostate cancer cell line,
respectively. • Another integrase inhibitor, L-000870812, and
two nucleoside reverse transcriptase inhibitors, zidovudine
(ZDV), and tenofovir disopr