New research results show a naturally-occurring virus destroys brain cancer cells growing in culture and in mice. The virus is reovirus, Respiratory Enteric Orphan, commonly found in the respiratory and gastrointestinal tract of people.
Dr. Peter Forsyth, a cancer researcher and physician with the Faculty of Medicine and the Alberta Cancer Board (ACB), and colleagues at the U of C, publish their research findings in today's issue of the Journal of the National Cancer Institute.
"It is extremely rewarding for me that some real hope for people with brain cancer is visible on the horizon," says Forsyth. "The average survival rate for patients with brain tumors is only one year. Only two percent of people with this disease live longer than three years. This discovery is a first step towards using reovirus to treat brain cancer."
Forsyth's co-authors on the research study include Elizabeth Wilcox, a U of C medical student, U of C researcher Patrick Lee, PhD, ACB scientist Wen Qing Yang, PhD, and colleagues from the U of C Cancer Biology Research Group.
Malignant gliomas, the most common form of brain tumor, are aggressive, invasive and resistant to existing treatments. The reovirus, Respiratory Enteric Orphan, is a virus commonly found in the respiratory and gastrointestinal tract of people.
It has previously been shown by Forsyth's colleague, Patrick Lee, PhD, that reovirus infects and destroys cancer cells, leaving normal cells untouched. Forsyth's study shows that when tested in cell cultures, reovirus killed 20 of 24 brain tumor cell lines. The research team also establishd that reovirus killed all nine primary cell cultures from brain tumors (gliomas) removed from patients.
The study finds that reovirus also attacked human tumors that were implanted into the brains of mice. After a single injection of live reovirus into these tumors, nine of 11 of these mice were alive after 90 days. None of the mice treated with dead virus survived that long.
Overall, the research results show that mice with brain tumors treated with live reovirus not only lived significantly longer, but also were healthier.
"Our findings in the lab tell us that reovirus is potentially a potent tool against specific kinds of brain tumors. But I want to emphasize that we have several years of research ahead of us before it can potentially be used as a treatment for brain cancer," says Forsyth.
Planning is underway for a clinical trial involving patients with brain tumors, sponsored by Oncolytics Biotech Inc., that is anticipated to start within the next six months.
Forsyth's research is supported by the National Cancer Institute of Canada (with funds from the Canadian Cancer Society), Alberta Cancer Board, Partners in Health, the Brain Tumor Foundation of Canada, the Dr. Michael Longinotto Molecular Neuro-Oncology Fellowship Fund and Mr. Clark Smith.
[Contact: Karen Thomas]