Bovine Leukemia Virus Gene Segment Detected in Human Breast Tissue

Abstract

Background: Bovine Leukemia Virus (BLV) is known by infections in bovine cattle and produce, in 30% of infected animals, persistent lymphocytosis significantly impacts the beef industry. It has been proposed that this virus could be transmitted to humans and be present in cases of breast cancer. Aim: to determine the presence of 380 bp of gag gene segment of BLV in paraffin-embedded breast tissue. Study Design: Control-case study. Methodology: 106 tissue samples were collected. 53 were cancer positive samples and 53 were negative samples for this pathology. After dewaxing tissues, DNA was extracted, amplified and sequenced. Phylogenetic analysis was done in order to verify BLV gene segment, presence and origin. Results: 43 samples were positive (40.5%) for BLV segment. In the case group this segment was found in 35.8% of the samples and in the control group, BLV presented in 45.2% of the samples. Phylogenetic analysis confirmed BLV presence and had shown a high homology between amplified gene sequences obtained from human breast tissues and those coming from bovine cattle with leukosis reported by GenBank. Conclusion: The presence of BLV genes in humans and its location in breast tissue can be confirmed, however, it should be clarified as a possible promoter of malignancy processes on this tissue.

Bovine leukemia virus presence in breast tissue of Argentinian women. Its association with cell proliferation and prognosis markers.

“…The current study results showed that BLV could be detected by in situ PCR in 22.36% of the females that the malignant breast tissue specimens originated in them. In similar studies performed in other countries, BLV DNA was present in a higher percentage of malignant tested tissues [6,13,33]. This difference could be due to the fact that samples were not processed from the beginning by the same operator, or, instead, since the number of samples was not large enough.…”

“…Other areas of the BLV genome transcribing microRNAs and other RNAs that regulate microRNAs, are recently associated with maintaining the transformed state of BLV-infected cells [29,30]. Retrotranscribed BLV DNA is detected in human breast tissue by standard solution PCR [13] and in situ PCR [6]. BLV structural proteins gp51 and p24 are also detected in human breast tissue [31].…”

“…In bovines, there is reported evidence of BLV transmission to calves through milk and blood [11]. In humans, presence of serum antibodies against BLV [12], and retrotranscribed DNA in breast tissue sections [6,13] and lung tumors [14] are reported. These findings, plus the close relationship of BLV with HTLV-1 and -2, led researchers to hypothesize that BLV could behave as a zoonotic agent, and its association with human breast cancer is postulated [7].…”

Effect of Cattle Leukosis on Milk and Dairy Products Safety and Quality

“…Ряд публикаций указывают на обнаружение провирусной ДНК вируса бычьего лейкоза в эпителиальных клетках молочных желез женщин, в том числе больным раком молочной железы, с выдвижением концепции, что вирус бычьего лейкоза влияет на дестабилизацию генома хозяина и приводит к развитию ракового перерождения клетки [15][16][17][18][19].…”

Near-Field Radar Microwave Imaging as an Add-on Modality to Mammography

“…Environmental factors such as exposure to ionizing radiation, inheriting certain genes such as BRCA1 and BRCA2, and, most importantly, lifestyle have been associated with an increase in the risk of breast cancer. For instance, the link between breast carcinogenesis and naturally occurring substances such as heterocyclic amines (HCAs), insulin-like growth hormone (IGF-I), animal estrogen (E2), and bovine leukaemia virus (BLV), which are ubiquitous in western and modern diets, have been substantiated with a vast body of evidence [4][5][6][7][8][9][10][11]. Nonetheless, not much has been done in updating the dietary guidelines and food policies to address the role of these substances, and similar ones, in cancer epidemic.…”