title: Prevalence of human xenotropic murine leukemia virus-related gammaretrovirus (XMRV) in Dutch prostate cancer patients.
abstract: BACKGROUND
  The occurrence of the retrovirus xenotropic murine leukemia virus (MLV)-related virus (XMRV) has been reported in prostate tissue of patients with prostate cancer (PrCa). Considering the potential great medical and social relevance of this discovery, we investigated whether this finding could be confirmed in an independent group of Dutch sporadic PrCa cases.
  
  
  METHODS
  We investigated the occurrence of XMRV in fresh-frozen PrCa specimens of 74 PrCa patients from The Netherlands. Total RNA and DNA were isolated, subjected to cDNA synthesis, and analyzed by real-time PCR targeting conserved XMRV sequences.
  
  
  RESULTS
  Spiking experiments showed that we were able to detect at least 10 copies of XMRV sequences in 100,000 cells by real-time PCR, demonstrating high sensitivity of the assay. XMRV sequences were detected in 3 out of 74 (i.e., 4%) PrCa specimens. The number of XMRV containing cells was extremely low (1 in 600-7,000 cells). This was corroborated by the fact that XMRV could not be detected in consecutive tissue sections of the initial XMRV-positive cases.
  
  
  CONCLUSIONS
  XMRV was rarely detected, and at extremely low levels, in sporadic PrCa samples from Dutch patients. When XMRV would play a causal role in prostate carcinogenesis, integration of the provirus could be expected to be present in, at least, a proportion of tumor cells. Therefore, our data do not support the claim that there is an association between XMRV infection and PrCa in Dutch PrCa patients.
authors.affiliation: Department of Urology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: Gerald W
authors.initials: GW
authors.lastname: Verhaegh
authors.forename: Arjan S
authors.initials: AS
authors.lastname: de Jong
authors.forename: Frank P
authors.initials: FP
authors.lastname: Smit
authors.forename: Sander A
authors.initials: SA
authors.lastname: Jannink
authors.forename: Willem J G
authors.initials: WJ
authors.lastname: Melchers
authors.forename: Jack A
authors.initials: JA
authors.lastname: Schalken
mesh_terms: D006801:Humans; D008297:Male; D009426:Netherlands; D016133:Polymerase Chain Reaction; D011471:Prostatic Neoplasms / Q000821:virology*; D012367:RNA, Viral / Q000032:analysis; D058008:Xenotropic murine leukemia virus-related virus / Q000302:isolation & purification*
chemical_list: D012367:RNA, Viral