title: Human Mammary Tumor Virus (HMTV) sequences in human milk.
abstract: BACKGROUND
  Retroviral sequences 90-95% homologous to the mouse mammary tumor virus (MMTV) were present in 38% of the breast cancers studied from American women and were not detectable in non-tumor breast tissue from the same patient. The entire proviral structure was described and viral particles were isolated from primary cultures of human breast cancer. This virus was designated as human mammary tumor virus (HMTV). Hormone response elements present in the HMTV Long-Terminal-Repeat (LTR) suggest a mechanism for association of HMTV with hormonally responding tissues. In fact, the incidence of HMTV sequences is higher in gestational breast cancers, which are associated with hormonal changes. Milk epithelial cells are also under hormonal regulation and therefore are excellent specimens for HMTV sequence detection.
  
  
  METHODS
  The HMTV sequence was studied in milk samples from lactating women recruited with increased risk of breast cancer because they had undergone breast biopsies (Biopsy-Group) and lactating women without breast biopsies (Reference-Group).
  
  
  RESULTS
  HMTV-env sequences were detected by PCR in milk of 7.61% of 92 women of the Reference-Group and in 20.55% of 73 women of the Biopsy-Group (p: 0.015). The sequences were 94-98% homologous to MMTV. HMTV-env and HMTV-env/LTR junction sequences were detected in high-speed pellet RNA, implying the presence of HMTV viral particles. PCR assays to detect the murine mitochondrial cytochrome oxidase gene and intracisternal-A-type particle sequences were performed to rule out mouse mitochondrial or genomic DNA contamination. Eight women of the 73 Biopsy-Group participants had breast cancer and the milk of only one of these eight women had HMTV-env sequences. In the remaining 65 women of the Biopsy-Group, under enough clinical suspicion to lead to biopsy, HMTV was detected in 14, nearly three times the number of milks as compared to the Reference-Group (21.54% versus 7.61%; p: 0.016).
  
  
  CONCLUSIONS
  The significance of HMTV in milk from the Reference-Group, the greater frequency in the milk of women who had undergone a breast biopsy and its possible infectivity for infants are important questions under study. The similarity of HMTV to MMTV is striking and suggests one possible avenue for viral transmission in humans.
authors.affiliation: The Tisch Cancer Institute and Department of Medicine, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Place, New York, NY 10029, USA.
authors.forename: Teiko
authors.initials: T
authors.lastname: Nartey
authors.affiliation: The Tisch Cancer Institute and Department of Medicine, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Place, New York, NY 10029, USA.
authors.forename: Heberth
authors.initials: H
authors.lastname: Moran
authors.affiliation: The Tisch Cancer Institute and Department of Medicine, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Place, New York, NY 10029, USA.
authors.forename: Tania
authors.initials: T
authors.lastname: Marin
authors.affiliation: Department of Veterinary and Animal Sciences, University of Massachusetts at Amherst, 240 Thatcher Road, Amherst, MA 01003, USA.
authors.forename: Kathleen F
authors.initials: KF
authors.lastname: Arcaro
authors.affiliation: Department of Sociology, Sloan College, University of South Carolina, Rm 321. 911 Pickens St., Columbia, SC 29208, USA.
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Anderton
authors.affiliation: The Tisch Cancer Institute and Department of Medicine, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Place, New York, NY 10029, USA.
authors.forename: Polly
authors.initials: P
authors.lastname: Etkind
authors.affiliation: The Tisch Cancer Institute and Department of Medicine, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Place, New York, NY 10029, USA.
authors.forename: James F
authors.initials: JF
authors.lastname: Holland
authors.affiliation: The Tisch Cancer Institute and Department of Medicine, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Place, New York, NY 10029, USA.
authors.forename: Stella M
authors.initials: SM
authors.lastname: Melana
authors.affiliation: The Tisch Cancer Institute and Department of Medicine, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Place, New York, NY 10029, USA ; Department of Microbiology, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Place, New York, NY 10029, USA.
authors.forename: Beatriz G-T
authors.initials: BG
authors.lastname: Pogo
keywords: Breast biopsies; Breast cancer; HMTV; Milk; Retrovirus