The development of anti-viral therapies to block cancer development and growth is a new and novel strategy to stop cancer. Approximately 15% of the cancers worldwide are associated with an infectious agent. Both bacteria and viruses can contribute to the oncogenic processes that lead to malignant transformation. Epstein-Barr virus (EBV) was the first virus to be associated with human cancer more than 40 years ago and continues to be an important health concern worldwide. EBV is a herpesvirus that has infected most of the world’s population. Infection during adolescence or early adulthood can lead to infectious mononucleosis, the primary disease associated with EBV. The virus remains in a mostly dormant state in some of the cells of the infected person for the rest of their life. However, under certain contexts or in the presence of other malfunctions of the normal cells the virus can contribute to cancer development. Certain types of cancer contain EBV and EBV proteins are expressed in the tumor cells. The presence of the virus and the expression of viral proteins in the tumor cells suggest that the virus contributes to cancer development. EBV is present in nearly all Burkitt’s lymphomas and in the majority of Hodgkin’s lymphomas. Nearly all lymphomas arising in the presence of immunodeficiencies, such as AIDS or after organ transplantation, contain EBV. A significant number of gastric carcinomas, nearly 90,000/year worldwide, and nearly all nasopharyngeal carcinomas are also associated with EBV. The viral oncogene, latent membrane protein 1 (LMP1), is expressed in most of the cancers associated with EBV. Previous studies suggest that LMP1 contributes to cancer by stimulating the growth and ensuring the survival of the tumor cells. The research of our laboratory is contributing new insights as to how LMP1 induces the growth and ensures the survival of cancer cells. The rationale is that these new insights will lead to new and novel therapeutic strategies to treat EBV-associated cancers. Such strategies would block the growth of tumors or induce the killing of the tumor cells. Furthermore, viral proteins often impinge on critical cellular pathways. Understanding how LMP1 influences normal cellular pathways to induce cancer may lead to strategies to inhibit the growth of other cancers whose growth is regulated in similar ways. Importantly the presence of the virus in these cancers offers a unique opportunity to kill the cancer cells by targeting the virus. In this way targeted therapies would have fewer side effects than traditional chemotherapeutic approaches. Long-term, our studies are expected to help identify new targets of therapeutic intervention for treatment of EBV-associated lymphomas and carcinomas, and possibly other cancers.
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Ansari M.A., Singh V.V., Dutta S., Veettil M.V., Dutta D., Chikoti L., Lu J., Everly D., Chandran B., “Constitutive Interferon-Inducible Protein 16-Inflammasome Activation during Epstein-Barr Virus Latency I, II, and III in B and Epithelial Cells.” J. Virology, 87: 8606-8623, 2013.
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Mainou B.A., Everly, D.N., Jr., and Raab-Traub N., Unique Signaling Properties of CTAR1 in LMP1-Mediated Transformation,” J. Virology 81: 9680-9692, 2007.
Feng, P., Everly, D.N., Jr., and Read, G.S., “mRNA Decay During Herpes Simplex Virus (HSV) Infections: Protein-Protein Interactions Involving the HSV Virion Host Shutoff Protein and Translation Factors eIF4H and eIF4A.,” J. Virology, 79: 9651-9664, 2005.
Mainou, B.A., Everly, D.N., Jr., and Raab-Traub, N., “Epstein-Barr Virus Latent Membrane Protein 1 CTAR1 Mediates Rodent and Human Fibroblast Transformation Through Activation of PI3K,” Oncogene, 24:6917-24, 2005.