title: Mouse mammary tumor like virus sequences in breast milk from healthy lactating women.
abstract: Mouse mammary tumor virus (MMTV) has been a long standing candidate as a potential cause of some human breast cancers. Forty years ago, electron microscopic images of MMTV-like particles were identified in milk from 5% of healthy lactating women. These observations, however, have not been confirmed by modern methods. The purpose of this study was to confirm the presence of MMTV-like DNA sequences in human milk from normal lactating women. Standard and in situ PCR analyses were conducted on DNA extracted from fresh breast milk samples collected from a group of 91 healthy lactating women volunteers. The MMTV-like viral positive PCR products were sequenced and a phylogenetic tree was constructed to compare these sequences. Immunohistochemistry analyses were performed on breast milk cells using polyclonal rabbit antibodies against affinity-purified MMTV envelope glycoproteins 52/36. MMTV-like envelope gene sequences were identified by PCR in 5% (4/91) of breast milk samples from healthy lactating women volunteers. These observations were confirmed by in situ PCR and immunohistochemistry using MMTV gp52/36 antibodies. These findings confirm the presence of MMTV-like gene sequences in human milk. As MMTV is transmitted via milk from mouse mothers to their newborn pups to cause mammary tumors when they become adults, this indicates a means of transmission of this virus in humans.
authors.affiliation: Prince of Wales Hospital, Randwick, NSW, Australia.
authors.forename: Harpreet
authors.initials: H
authors.lastname: Johal
authors.forename: Caroline
authors.initials: C
authors.lastname: Ford
authors.forename: Wendy
authors.initials: W
authors.lastname: Glenn
authors.forename: Joy
authors.initials: J
authors.lastname: Heads
authors.forename: James
authors.initials: J
authors.lastname: Lawson
authors.forename: William
authors.initials: W
authors.lastname: Rawlinson
mesh_terms: D000818:Animals; D001483:Base Sequence; D020077:Endogenous Retroviruses / Q000235:genetics; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D006801:Humans; D007774:Lactation; D008324:Mammary Tumor Virus, Mouse / Q000235:genetics / Q000302:isolation & purification*; D051379:Mice; D008895:Milk, Human / Q000821:virology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D015995:Prevalence; D016415:Sequence Alignment; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D014759:Viral Envelope Proteins