Table 2. The role of different EBV-encoded latent genes during latency and tumorigenesis [102].
| Latent genes | Role of genes |
|---|---|
| EBNA-1 | Transactivator of viral latent genes and host genes; responsible for episome replication, segregation and persistence of viral genome; involved in p53 degradation and oncogenesis. |
| EBNA-LP | Transcriptional co-activator of EBNA-2-dependent viral and cellular gene transcription; It is essential for EBV-mediated B-cell transformation. |
| EBNA-2 | Activates viral and cellular gene transcription for transformation. It is critical for EBV-mediated B-cell transformation. |
| EBNA-3A | A co-activator of EBNA-2, downregulate cMyc transcription and block EBNA-2 activation effects; and induce CDKN2 and chemokines. It is essential for EBV-mediated B-cell transformation. |
| EBNA-3B | A co-activator of EBNA-2; dispensable for B-cell transformation; viral tumor suppressor; and up regulates CXCL10. EBNA-3B-knockout induces DLBCL-like tumors. |
| EBNA-3C | ates with EBNA-2 host CXCR4 and CXCL12 genes; overcomes EBV-infection-mediated DNA damage response; promotes cell proliferation; induces G1 arrests; It is essential for EBV-mediated B-cell transformation. |
| LMP-1 | Mimics the constitutively active form of CD40, activates NF-κB, JNK and p38 pathways; is critical for EBV-mediated B-cell transformation. |
| LMP-2A | Responsible for constitutive activation of the ERK/MAPK pathway224; blocks antigen-dependent BCR signaling; induces B-cell lymphoma in transgenic condition. It is important but not essential for in vitro primary B-lymphocyte growth transformation. |
| EBER | Augments colony formation and induces growth; confers cells resistance to PKR-dependent apoptosis; induces cytokines and modulates innate immune response; contributes to EBV oncogenesis. |
| miRNAs | Has a role in sustaining latently infected cells. BHRF1 miRNA and BART miRNAs interfere with apoptosis. |
BART, BamHI-A region rightward transcript; BHRF1, BamHI fragment H rightward open reading frame 1; EBV, Epstein-Barr virus; EBER, EBV-encoded nuclear antigen; EBNA, EBV nuclear antigen; LMP, Latent membrane protein, BHRF1, BamHI fragment H rightward open reading frame 1; MAPK, mitogen-activated protein kinase; NF-κB, nuclear factor-κB; BCR, B cell receptor; PKR, RNA-dependent protein kinase; JNK, c-Jun N-terminal kinase.