The possible involvement of virus in breast cancer

Abstract

It is well known that the etiology of human breast cancer is significantly affected by environmental factors. Virus-associated cancer refers to a cancer where viral infection results in the malignant transformation of the host's infected cells. Human papillomaviruses (HPV), mouse mammary tumor virus (MMTV) and Epstein-Barr (EBV) virus are prime candidate viruses as agents of human breast cancer. The precise role that viruses play in tumorigenesis is not clear, but it seems that they are responsible for causing only one in a series of steps required for cancer development. The idea that a virus could cause breast cancer has been investigated for quite some time, even though breast cancer could be a hereditary disease; however, hereditary breast cancer is estimated to account for a small percentage of all breast cancer cases. Based on current research, this review present at moment, substantial, but not conclusive, evidence that HPV, EBV and MMTV may be involved in breast cancer.

The Signal Peptide of Mouse Mammary Tumor Virus-Env: A Phosphoprotein Tumor Modulator

“…5; and references therein), a number of reports from different groups do suggest an association between MMTV (or HMTV-human mammary tumor virus) sequences and breast cancer in up to 74% of women with the disease (related to geographical distribution; refs. [6][7][8]. Indeed, it has recently been reported (9) that inflammatory breast cancers from American women show a higher incidence of HMTV-related viral sequences (71%) than sporadic breast cancers, and that the presence of MMTV-env-like exogenous sequences is strictly related to tumor progression (10).…”

Investigation of human papillomaviruses (HPV), mouse mammary tumour virus (MMTV), Epstein–Barr virus (EBV), and human polyomavirus entities in canine mammary tumours

“…Many studies have evaluated viruses in human tumours and BC as a potential aetiological factor (1,4,9,16). In virus-associated cancer, the viral infection causes a malignant transformation of the host's infected cells.…”

“…In virus-associated cancer, the viral infection causes a malignant transformation of the host's infected cells. Human papillomaviruses (HPV), MMTV, and Epstein-Barr (EBV) viruses are prime candidates as agents of human BC (1). In a previous study, MMTV was detected in BC, but not in normal breast tissue, and the study also reported that the virus spread rapidly in human BC cell cultures (1).…”

“…Although the exact role of viruses in tumour development is not clear, it is known that viruses may contribute to the development of human tumours by different mechanisms: indirectly by inducing immunosuppression or by modifying the host cell genome without persistence of viral DNA; and directly by inducing oncoproteins or by altering the expression of host cell proteins at the site of viral DNA integration (1). Due to these effects, Lawson and Heng (13) believed that the scientific issue has evolved from "are viruses present in BC?"…”

Lack of Detection of the Mouse Mammary Tumor-like Virus (MMTV) Env Gene in Iranian Women Breast Cancer using Real Time PCR

“…Mouse mammary tumor virus (MMTV) is the major cause of mammary tumors in mice (Bittner, 1936), which could be transmitted as an endogenous provirus or like an exogenous infectious agent (Amarante et al, 2009). A virus called MMTV-like virus has about 95% sequence homology to MMTV (Lawson et al, 2006).…”