Epstein‑Barr virus as a promoter of tumorigenesis in the tumor microenvironment of breast cancer (Review)

Epstein‑Barr virus (EBV) is an oncovirus associated with various neoplasms, including breast cancer (BC). EBV‑associated oncogenesis requires the action of several viral molecules, such as EBV nuclear antigen 3C, latent membrane protein 1, microRNAs and long non‑coding RNAs, which are able of manipulating the cellular machinery, inducing an evasion of the immune system, blocking apoptosis processes, promoting cell survival and metastasis. The risk of developing cancer is associated with epigenetic alterations and alterations in various signaling pathways. The activation of all these molecules can modify the expression of EBV proteins with oncogenic activity, influencing the oncogenic process. It is clear that BC, being multifactorial, presents a greater complexity; in numerous cases, the infection associated with EBV may be crucial for this neoplasia, if particular conditions for both the virus and host are present. In the present review, all these variables are analyzed in an aim to improve the understanding of the participation of EBV in BC.