"Hitch-hiking" cold virus may target, treat cancer
(CBS News) Can the common cold one day help cure cancer? That's what scientists are hoping after a study reported on a promising new treatment in which a "hitch-hiking" virus sneaks up on tumors undetected.
The virus, called a reovirus, causes respiratory infections such as the common cold and gastrointestinal infections like Rotavirus or diarrhea. But, after it's injected into cancer patients' bloodstreams - similar to standard chemotherapy agents - the virus targeted cancer cells, attacking them directly. It also went a step further to trigger an immune system response to help eliminate any remaining cancer cells.
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"Viral treatments like reovirus are showing real promise in patient trials," Study co-author Dr. Kevin Harrington, a reader in biological cancer therapies at The Institute of Cancer Research, said in a news release. "This study gives us the very good news that it should be possible to deliver these treatments with a simple injection into the bloodstream."
For the new study, published in the June 13 issue of Science Translational Medicine, researchers from the University of Leeds and The Institute of Cancer Research put the new treatment to the test with 10 patients with advanced bowel cancer who were due to have surgery because the tumors had spread to their livers. All patients were given five doses of the reovirus before surgery was set to take place.
The scientists discovered that the virus "hitched" a ride on blood cells to reach the tumors undetected. Not only did the virus stay active during its journey through the bloodstream, the researchers said, but it also homed in on tumor cells, ignoring nearby healthy tissue. This was evidenced during the patients' surgeries when scientists found active viruses inside the liver tumor cells but not in the surrounding normal liver tissue.
"It seems that reovirus is even cleverer than we had thought," study co-author Professor Alan Melcher, a clinical oncology and biotherapy researcher at the University of Leeds, said in the news release. "By piggybacking on blood cells, the virus is managing to hide from the body's natural immune response and reach its target intact," he said, adding this could be "hugely significant" for using viral therapies like this in doctors' offices.
Blood tests also showed the virus was eliminated from the patients' bloodstreams once it reached the tumor cells after hitching a ride. The study didn't however look at whether the virus could successfully destroy the tumors or could prolong patients' lives. Much more research will need to be conducted before such a therapy can be used in doctors' offices worldwide.
''This promising study shows that reovirus can trick the body's defenses to reach and kill cancer cells and suggests that it could be given to patients using a simple injection," Dr. Julie Sharp, from the charity Cancer Research UK which part-funded the research, said in a press release.
''We look forward to seeing how this research develops and if this could one day become part of standard cancer treatment.''
