title: No evidence for the involvement of XMRV or MCV in the pathogenesis of breast cancer.
abstract: BACKGROUND
  The aetiology of breast cancer remains elusive. A viral aetiology has been proposed, but to date no virus has been conclusively demonstrated to be involved. Recently, two new viruses, namely Merkel cell polyomavirus (MCV) and xenotropic murine leukaemia virus-related virus (XMRV) have been identified and implicated in the pathogenesis of Merkel cell carcinoma (MCC) and familial form of prostate cancer, respectively.
  
  
  METHODS
  We examined 204 samples from 58 different cases of breast cancer for presence of MCV or XMRV by PCR. Samples consisted of both malignant and non-malignant tissues. Additionally, we included 6 cases of MCC and 12 cases of prostate cancer as potential controls for MCV and XMRV, respectively.
  
  
  RESULTS
  All of the breast cancer samples examined were negative for both MCV and XMRV. However, 4/6 MCC and 2/12 prostate cancer samples were found to be positive for MCV and XMRV, respectively. Sequence analysis of the amplified products confirmed that these sequences belonged to MCV and XMRV.
  
  
  CONCLUSIONS
  We conclude that there is no evidence for the involvement of MCV or XMRV in the pathogenesis of breast cancer. What role these viruses have in the pathogenesis of MCC and prostate carcinomas remains to be demonstrated.
authors.affiliation: Department of Microbiology, Faculty of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates. g_khan@uaeu.ac.ae
authors.forename: G
authors.initials: G
authors.lastname: Khan
authors.forename: P S
authors.initials: PS
authors.lastname: Philip
authors.forename: M
authors.initials: M
authors.lastname: Naase
authors.forename: K M I
authors.initials: KM
authors.lastname: Al Zarouni
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001483:Base Sequence; D001943:Breast Neoplasms / Q000821:virology*; D015266:Carcinoma, Merkel Cell / Q000821:virology*; D005260:Female; D006801:Humans; D008297:Male; D059965:Merkel cell polyomavirus / Q000235:genetics; D008875:Middle Aged; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000592:standards; D027601:Polyomavirus Infections / Q000150:complications / Q000821:virology*; D011471:Prostatic Neoplasms / Q000821:virology*; D012015:Reference Standards; D012192:Retroviridae Infections / Q000150:complications / Q000821:virology*; D017422:Sequence Analysis, DNA; D014412:Tumor Virus Infections / Q000150:complications / Q000821:virology*; D058008:Xenotropic murine leukemia virus-related virus / Q000235:genetics; D055815:Young Adult