CHAPEL HILL - Scientists at the University of North Carolina at Chapel Hill, working with colleagues in Japan, have proven that a protein called latent membrane protein 1 in Epstein-Barr virus causes a form of cancer known as B cell lymphoma in mice.
The work is important, the scientists say, because it shows the protein's central role in Epstein-Barr virus' ability to change normal cells into cancerous ones. That virus already is known to cause infectious mononucleosis in humans and has been associated with such malignancies as Burkett's lymphoma, Hodgkin's lymphoma and nose and throat cancer. It is especially hazardous to AIDS patients and other patients whose immune systems have weakened.
"We have shown for the first time that Epstein-Barr virus clearly can cause cancer," said Dr. Nancy Raab-Traub, professor of microbiology at the UNC-CH School of Medicine and a member of the UNC Lineberger Comprehensive Cancer Center. "Now we can go after the specific protein that is responsible and perhaps one day stop that protein function and prevent the cancer from growing."
The first report on the continuing research appeared in the Proceedings of the National Academy of Sciences last year, and a second describing additional findings is being published in Friday's (Oct. 8) issue of the journal Science.
In the Proceedings paper, Raab-Traub and her colleagues described breeding three different lines of laboratory mice into which the latent membrane protein 1 (LMP1) from Epstein-Barr virus was genetically incorporated. Lymphoma developed in all three strains of mice, which are known as transgenic mice, and had affected 42 percent of the animals within 18 months.
Investigators detected the protein in high concentrations in cancerous tissue, but only in trace amounts in normal lymph system tissues.
"This work demonstrated that LMP1 alone -- without expression of other
Epstein-Barr virus genes -- causes
Contact: David Williamson
University of North Carolina at Chapel Hill