COLUMBUS, Ohio Cancer-killing viruses are a promising therapy for incurable brain tumors, but their effectiveness has been limited in part because immune cells rapidly move in and eliminate them.
That immune response might be slowed, and the virus given more time to kill cancer cells, by blocking the growth of blood vessels in the tumor, new research here suggests.
The animal study indicates that pretreatment with an antiangiogenic agent a drug that blocks blood-vessel growth might improve the effectiveness of cancer-killing viruses.
The study, led by researchers at the Ohio State University Comprehensive Cancer Center, is published online in the Journal of the National Cancer Institute with an accompanying editorial.
Our work suggest that antiangiogenic agents can reduce virus-induced inflammation in brain-tumor tissue and improve the antitumor efficacy of oncolytic virus therapy by lengthening the time it takes the immune system to clear the virus, says principal investigator Balveen Kaur, assistant professor of neurological surgery.
Much additional work is needed to validate these findings in other tumor models, but we hope that our findings will eventually be translated into clinical trials and one day help patients.
Kaur and her colleagues set out to learn how a cancer-killing, or oncolytic, virus affected the blood vessels in a brain-tumor model.
Kazuhiko Kurozumi, a visiting research scholar from Japan in Kaurs laboratory, first implanted rat glioma cells into the brains of several groups of rats. Seven days later, he injected a cancer-killing virus, called hrR3, into the growing tumors. This virus is a modified form of herpes simplex virus type 1 that reproduces and kills only tumor cells.
The virus caused the tumor blood vessels to become significantly more leaky compared with tumor blood vessels from control animals, and high numbers of white blood cells immune cells entered the tumor tissue.
|Contact: Darrell E. Ward|
Ohio State University