title: A mouse mammary tumor virus env-like exogenous sequence is strictly related to progression of human sporadic breast carcinoma.
abstract: A viral etiology of human breast cancer (HBC) has been postulated for decades since the identification of mouse mammary tumor virus (MMTV). The detection of MMTV env-like exogenous sequences (MMTVels) in 30% to 40% of invasive HBCs increased attention to this hypothesis. Looking for MMTVels during cancer progression may contribute to a better understanding of their role in HBC. Herein, we analyzed HBC preinvasive lesions for the presence of MMTVels. Samples were obtained by laser microdissection of FFPE tissues: 20 usual-type ductal hyperplasias, 22 atypical ductal hyperplasias (ADHs), 49 ductal carcinomas in situ (DCISs), 20 infiltrating ductal carcinomas (IDCs), and 26 normal epithelial cells collateral to a DCIS or an IDC. Controls included reductive mammoplastic tissue, thyroid and colon carcinoma, and blood samples from healthy donors. MMTVels were detected by fluorescence-nested PCR. DNA samples from the tissues of nine patients were analyzed by real-time quantitative PCR, revealing a different viral load correlated with stage of progression. Furthermore, as never previously described, the presence of MMTVels was investigated by chromogenic in situ hybridization. MMTVels were found in 19% of normal epithelial cells collateral to a DCIS or an IDC, 27% of ADHs, 82% of DCISs, and 35% of IDCs. No MMTVels were found in the control samples. Quantitative PCR and chromogenic in situ hybridization confirmed these results. These data could contribute to our understanding of the role of MMTVels in HBC.
authors.affiliation: Division of Surgical, Molecular, and Ultrastructural Pathology, University of Pisa and Pisa University Hospital, Pisa, Italy.
authors.forename: Chiara Maria
authors.initials: CM
authors.lastname: Mazzanti
authors.forename: Mohammad
authors.initials: M
authors.lastname: Al Hamad
authors.forename: Giovanni
authors.initials: G
authors.lastname: Fanelli
authors.forename: Cristian
authors.initials: C
authors.lastname: Scatena
authors.forename: Francesca
authors.initials: F
authors.lastname: Zammarchi
authors.forename: Katia
authors.initials: K
authors.lastname: Zavaglia
authors.forename: Francesca
authors.initials: F
authors.lastname: Lessi
authors.forename: Mauro
authors.initials: M
authors.lastname: Pistello
authors.forename: Antonio Giuseppe
authors.initials: AG
authors.lastname: Naccarato
authors.forename: Generoso
authors.initials: G
authors.lastname: Bevilacqua
mesh_terms: D001483:Base Sequence; D001943:Breast Neoplasms / Q000473:pathology* / Q000821:virology*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000473:pathology / Q000821:virology; D018450:Disease Progression; D004847:Epithelial Cells / Q000473:pathology; D005260:Female; D015752:Genes, env / Q000235:genetics*; D006801:Humans; D017403:In Situ Hybridization; D007834:Lasers; D008324:Mammary Tumor Virus, Mouse / Q000235:genetics*; D042282:Microdissection; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D019562:Viral Load