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DURHAM, N.C. -- A common human virus may prove useful in
attacking the deadliest form of brain tumors, according to
study conducted by researchers at Duke's Preston Robert Tisch Brain
Tumor Center. The researchers said the finding is an
important step in developing a vaccine that can attack the
tumors by enlisting the help of the body's immune system.

Human cytomegalovirus (HCMV), which infects 50 percent to 90
percent of people at some point during their lives, is active
in more than 90 percent of patients diagnosed with glioblastoma
multiforme, the most deadly type of malignant brain tumor, said
Duane Mitchell, M.D., Ph.D., a brain cancer researcher and lead
investigator on the study.

"We don't know if the virus plays a part in the growth of
the brain tumors or whether the presence of the brain tumors
leads to a reactivation of the virus," Mitchell said. "But we
do know that the virus has the potential to affect the growth
and invasiveness of cancer cells. So if we can target it, we
may be able to empower the body's immune system to fight
infected tumor cells and destroy the cancer."

According to the researchers, a vaccine targeting HCMV
likely would be administered to patients following conventional
chemotherapy. The immune system's recovery from chemotherapy is
marked by a regenerative burst of new immune cells, and the
vaccine would take advantage of this reaction to effect an even
stronger immune response to the virus, Mitchell said.

The researchers will publish their findings in the February
2008 print issue of the journal Neuro-Oncology. The study was
published early online on October 19, 2007. The research was
funded by the National Institutes of Health, The Brain Tumor
Society and Accelerate Brain Cancer Cure, a not-for-profit
organization that supports research to hasten a cure for brain
cancer.

In healthy people with fully functional immune systems, the
initial HCMV infection can be symptom-free or it can be
associated with mild flulike symptoms. After infection, the
virus becomes dormant and stays that way for the life of the
infected person. But in people with weakened immune systems --
such as AIDS patients or those undergoing bone marrow
transplant -- HCMV can become reactivated and cause more severe
illnesses, such as pneumonia.

HCMV's association with brain tumors was first demonstrated
in 2002 by researchers at the University of Alabama -
Birmingham, but their results had not been repeated despite
several attempts.

"We not only confirmed the virus' association with the
tumors but also saw that patients with glioblastoma multiforme
had detectable virus in their bloodstreams, where the
comparative group did not," Mitchell said. "This association
may help us assess the success of vaccine treatment, since we
will be better able to monitor response in patients, even after
their tumors have been removed."

Based on the results of this study, Duke researchers have
developed a vaccine that targets HCMV and are conducting a
clinical trial to assess the vaccine's safety and its
effectiveness at building immunity to HCMV in patients with
brain tumors. In the trial, which will complete enrollment this
year, the vaccine is given monthly to cancer patients in
conjunction with chemotherapy for as long as their tumors
remain stable.

"We're encouraged by the early results we're seeing in the
clinical trial and we're pleased that the initial study enabled
us to proceed with testing this vaccine in patients," Mitchell
said. "Because HCMV is present in such a large number of
glioblastoma multiforme patients, the development of an
effective treatment that targets the virus could have
significant implications for this deadly disease."

Other researchers involved in this study were Weihua Xie,
Robert Schmittling, Chris Learn, Allan Friedman, Roger McLendon
and John Sampson.