The Epstein-Barr virus, the most common culprit of mono, infects most people and is linked to cancer later in life. Researchers at the UW-Madison McArdle Laboratory for Cancer Research and the German National Research Center for Environmental Health have discovered information about the virus's lifecycle which could lead to virus-specific, targeted treatments for certain cancers.
The study was completed by UW-Madison professor of oncology Bill Sugden and his colleague, professor Wolfgang Hammerschimdt of Munich, Germany. Hammerschmidt came to Madison in 1986 to work with Sugden as a postdoctoral fellow. Hammerschmidt now works in Munich and has been collaborating with Sugden on EBV research since then.
EBV, is a member of the herpesvirus family and can contribute to the development of different forms of cancer, including Burkitt's lymphoma and nasopharyngeal carcinoma, according to the Center for Disease Control and Prevention.
Sugden and his students had previously found that the viral protein EBNA-1 supports the survival of tumors related to EBV. This finding is important because EBNA-1 is present in all diseases caused by EBV.
Now Hammerschmidt, Sugden and their students have taken steps towards understanding more about the relationship between EBV and the tumors.
Sugden, who has studied EBV for 33 years, explained, ""The viral protein which is essential to keep EBV-positive tumors alive regulates transcription."" Transcription, or RNA synthesis, is the process of reading DNA into RNA, which is then translated into proteins.
Viruses, including EBV, can introduce new genetic information into cells and take over the cells' functions. This new information from the viruses can promote the formation of cancers.
The researchers hypothesize that a cellular protein binds a 25-amino acid segment of EBNA-1, allowing transcription of genes that EBNA-1 regulates. This cellular protein still needs to be identified.
If the cellular protein is identified, then the researchers hope to develop drugs to inhibit EBNA-1's interaction with it and prevent the survival of EBV-positive tumors. Such drugs would be used to treat EBV-positive tumors therapeutically.
The ultimate goal of the research is to create a virus-specific tumor therapy. A targeted therapy aims to destroy only cancer cells, with minimal harm on the other healthy cells, according to the National Foundation for Cancer Research.
Current therapies for cancer are broad-acting and may result in negative side effects for normal cells, which consequently are damaged in the process of treating the cancer cells.
If a virus-specific treatment was found, then it could be used to treat cancers caused by EBV without the harmful side effects patients experience with current therapies.
""Our goal is to understand enough about how EBV supports the growth and survival of EBV-positive tumors so we can target that contribution specifically and have no side effects on other cells,"" Sudgen said.
There are currently no antiviral drugs or vaccines available for tumors related to EBV. Varicella zoster virus, which causes shingles or chicken pox, is the only human herpesvirus for which there is a vaccine.
