Virus Infection Battles Brain Cancer

March 10, 2008 -- Curing a disease by causing another one seems counter-intuitive, but that's just what scientists at Yale University have done.

Specifically, they have modified a virus and injected it into mice with several kinds of inoperable brain cancer. Three days later, the tumors were gone.

The research, which builds on previous attempts to use viruses to treat cancer, could eventually treat otherwise fatal brain tumors in people, as well as other forms of cancer. While a human treatment is still years away and subject to federal approval, a tumor-killing virus could be a last-resort try at saving lives.

"The brain cancers we look at are very nasty," said Anthony Van den Pol, a scientist at Yale University and a study author. "This virus is pretty good at killing all of the tumor cells."

While surgery or other treatments can be used for some brains cancers, many tumors are inoperable. And even in the case of treatable tumors, it takes just a few surviving cells to cause the re-growth of new tumors, years later.

For the new treatment, the researchers used a virus related to rabies called vesicular stomatitis virus (VSV). Endemic to Central America, the virus causes mild, cold-like symptoms in humans and is based on single-stranded RNA instead of the doubled-up DNA.

The virus causes an active infection, rather than a harmless immune reaction as a typical vaccine would. Its infectiousness will likely limit its use as a therapy, the researchers admit.