Genetically engineered poliovirus fights br...( What do you get when you cross a pol...)

What do you get when you cross a poliovirus with the virus that causes the common cold? An efficient mechanism for killing brain tumors, say scientists at Duke University, who have successfully used the genetically modified poliovirus to cure brain tumors in mice. They report their results at the 101st General Meeting of the American Society for Microbiology.

"Malignant glioma (the most common type of brain tumor) is almost always fatal, due to very poor response to surgery, radiation and chemotherapy," says Matthias Gromeier, in whose laboratory the research was conducted. "We have developed a new form of therapy against malignant glioma based on viruses that can cause brain infections in humans."

The creation of this new therapy began when Gromeier and his colleagues discovered that the molecule that the poliovirus binds to on human cells, CD155, is abnormally expressed on malignant gliomas. This meant that the poliovirus would naturally target brain tumors. Unfortunately, the use of the virus as a treatment was severely limited by its ability to cause polio in humans.

"We genetically engineered a poliovirus variant that lost its ability to cause disease in humans. We accomplished this task by inserting a piece of genetic information of rhinovirus (the virus that causes the common cold) into the poliovirus genome," says Gromeier. "The mixed polio/rhinovirus construct had very surprising properties: it had lost its ability to cause poliomyelitis in humans, but retained excellent killing potential for malignant glioma cells."

They tested the abilities of this new hybrid virus using mice with experimental brain tumors. The animals recovered after a single dose of the virus. "Pathological analysis of their brains revealed tumors to be eliminated by replicating virus within days," says Gromeier.

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Contact: Jim Sliwa
jsliwa@asmusa.org
202-942-9297
American Society for Microbiology
20-May-2001