Mouse mammary tumor-like virus (MMTV) is present in human breast tissue before development of virally associated breast cancer

• Published in: Infectious agents and cancer Vol. 12; no. 1; p. 1
• Main Authors: Nartey, Teiko, Mazzanti, Chiara M, Melana, Stella, Glenn, Wendy K, Bevilacqua, Generoso, Holland, James F, Whitaker, Noel J, Lawson, James S, Pogo, Beatriz G T
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 04.01.2017; BioMed Central
• Subjects: Breast cancer; Identification and classification; Physiological aspects; Retroviruses; Tissues (Anatomy); Histological; Benign breast tissues; HMTV; MMTV; Morphology; Mouse mammary tumor-like virus; Human mammary tumour virus; Breast cancer; MMTV-like; Histotype; Mouse mammary tumor virus; Morphological
• ISSN: 1750-9378; 1750-9378
• DOI: 10.1186/s13027-016-0113-6

There is substantial evidence that a virus homologous to mouse mammary tumor virus (MMTV) may have a role in human breast cancer. The present study indicates that those who developed breast cancer associated with an MMTV-like virus had this virus in their non-cancerous breast tissues years before the cancer developed. Polymerase chain reaction (PCR) techniques and sequencing were used to identify MMTV-like envelope gene sequences (MMTV-like sequences) in Australian benign breast biopsy specimens from women who several years later developed breast cancer. Murine contamination was excluded by stringent laboratory procedures, and the absence of intracisternal A particle sequences and mitochondrial cyclooxygenase sequences. MMTV-like sequences (also called HMTV sequences to denote their source) were found in 9 of 25 breast cancer specimens (36%). Among 25 non-cancerous breast biopsies of these same patients taken 1 to 11 years earlier, six contained MMTV-like sequences (24%). Five of the six were among the nine virally-associated breast cancers. In two pairs of specimens, benign and malignant, sequences were 97% identical. The identification of MMTV (MMTV-like) sequences in breast tissues prior to the development of MMTV positive breast cancer fulfills a key criterion for a possible causal role for the MMTV-like virus in human breast cancer.