GAINESVILLE -- Researchers at the University of Florida have successfully immunized laboratory mice against melanoma, one of the more aggressive forms of skin cancer.
So far, immunized mice have survived for as long as 150 days after exposure to active melanoma cells. Unprotected mice died in a matter of weeks, said Howard Johnson, a graduate research professor of microbiology and cell science with UF's Institute of Food and Agricultural Sciences who heads up the project.
"If we just vaccinate mice with inactivated tumor cells, we get very little protection," Johnson said. "But if we vaccinate the mice with inactivated tumor cells and then give them superantigens, we significantly extend the survival of the mice."
Superantigens are proteins that are strong stimulators of the immune system. The researchers use the superantigens to boost the response to a vaccine, in this case an injection of dead melanoma cancer cells, Johnson said.
The results of the UF research will be presented April 2 at the national conference of the American Association for Cancer Research in San Francisco.
The research is based on the same process doctors have been using for years to protect people against illnesses such as polio, whooping cough and the flu, Johnson said.
"The interesting thing about vaccination against infectious diseases is that it's not a miraculous event," Johnson said. "What you basically do is inject a part of the harmful organism into an individual under circumstances that will not allow it to grow or cause disease.
"What you've done is stimulate the immune system of the individual so that it is revved up and is able to kill the infectious agent before it can get a foothold," he said. "Theoretically, one could use a similar approach dealing with cancers."
The problem, according to another UF researcher, is that an individual's immune system doesn't immediately recognize a cancer as something it needs to fight.