MONDAY, July 18, 2005 (HealthDay News) -- Among all the various cancer treatments currently under research, one of the hottest involves a genetically engineered version of the common cold virus.
The theory is this: the germs that cause the sniffles could wipe out tumor cells, too. And there's a twist: heat might help the virus become an even more powerful killing machine.
In a new study, researchers report that raising the temperature of cancer cells to the level of a high fever makes it easier for the germs to kill them.
The heat-based research is preliminary, and treatment with the common cold virus isn't ready for primetime. Still, researchers hope they may be on to something.
This heat-and-virus combo treatment "has a lot of potential," said study co-author Clodagh O'Shea, a research specialist at the University of California, San Francisco. His team published their latest findings in the July issue of Cancer Cell.
The idea of treating cancer with a virus has been around for a few years. Viruses are extremely simple organisms that use machinery inside host cells to replicate.
In this research -- involving a cold germ called ONYX-015 -- researchers worked on the premise that the virus will infect cancer cells and then kill them as ONYX-015 hijacks cellular machinery to replicate itself.
By contrast, many existing cancer drugs only prevent tumor cells from reproducing, leaving existing cells alive to potentially create havoc later on.
Researchers have been testing the virus therapy on patients with head, neck and liver cancer, O'Shea said. Some cancer patients failed to respond during early tests of treatment with the common cold virus. According to O'Shea, researchers thought heat levels in their bodies had something to do with their response, so they tested their theory in tumor cells in the laboratory.
O'Shea and colleagues found that the tumor cells became more susceptible to the killing powers of the virus when they were heated to 102.9 degrees Fahrenheit, equivalent to a high fever.
Enduring a fever, of course, isn't pleasant. But if it makes cancer cells more vulnerable, "that's probably a reasonable tradeoff," O'Shea said. It's also possible that drugs could do the job of heating cancer cells to the appropriate point, she said.
Dr. Gennadi V. Glinsky, a senior scientist at the Ordway Cancer Center in Albany, N.Y. who's familiar with the study findings, said they're promising and build on previous research into the use of heat to boost other cancer treatments. The heat idea "has been around a while, but it didn't really gain the value to be put into the approach of standard therapy," he said. "But maybe in this case there will be a good combination."
However, he noted that the researchers didn't try out the heat theory on animals, the next step before moving to tests in humans. And he said there's another potential problem: if the main treatment with the cold virus doesn't work -- researchers haven't completed the final stage of testing in humans -- the heat issue will probably be moot.
Learn more about cancer treatment from the American Cancer Society.