Bovine Leukemia Virus Presence in Breast Tissue of Argentinian Females and its Association With Cell Proliferation and Prognosis Markers

MARTINEZ CUESTA, LUCIA; DOLCINI, GUILLERMINA LAURA; NIETO FARIAS, MARIA VICTORIA; BUEHRING, GC; LENDEZ, PAMELA ANAHI; SHEN H; CERIANI, MARIA CAROLINA

Lims

Congreso; 19th International Congress HTLV 2019; 2019

International Retrovirology Association

Introduction: Bovine leukemia virus (BLV) causes enzootic bovine leukemia and is closely related to human T-lymphotropic virus type 1. It expresses microRNAs of unknown function and codes Tax, the protein that mediates malignant transformation. BLV is capable of infecting B- and T-lymphocytes, endothelial cells, and mammary epithelial cells of cattle. Several studies demonstrated the presence of BLV DNA in human tissue, and it is significantly associated with breast cancer in case-control studies using in situ PCR, a highly sensitive and specific technique.Objective: 1) To determine the presence of BLV DNA in breast malignant tissue, from females in Argentina. 2) To associate the presence of BLV DNA with the most common prognosis factors determinations recommended for cancer treatment design.Material and methods: Archived formalin-fixed paraffin-embedded (FFPE) human breast cancer samples (n=85) were randomly selected disregard of age or diagnosis from the biorepository of a private laboratory, from a city with 140,000 inhabitants, located in the Central area of Argentina. The patient´s age range fluctuated from 29 to 84 years. In situ PCR methodology was employed to amplify a 114-bp DNA segment from the tax gene region. Immunohistochemical techniques were used to determine the presence of hormonal receptors (Estrogen and Progesterone), and levels of expression of proliferation marker Ki67 and oncogene HER-2. The association between the presence of BLV DNA, the hormonal receptors, expression of HER-2 and the proliferative index marker Ki67, was estimated with the Chi-square test (P