Researchers successfully immunize mice against aggressive cancer

March 13, 2000

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.

"This isn't an invading bacteria or virus, these are your own cells, and the immune system is primed to not mount an immune response against itself," said Barbara Torres, assistant scientist in UF's department of microbiology and cell science. "So when you get immune response against cancer, part of the problem is that it's foreign and yet it's not, so you get a weaker response."

"The superantigen amplifies the immune response so it becomes a very strong response and can eradicate the tumor," she said.

Johnson characterized the battle between the immune system and a cancer as a "tug of war," in which the immune system wants to defend against the cancer but just can't manage it on its own.

"Unfortunately in a significant amount of people, the immune system doesn't respond fast enough to be protective against cancer," Johnson said. "With superantigens, we are trying to simply tip the scale more in favor of the immune system against this cancer."

Johnson said the logical conclusion to be drawn from the research is that someday individuals will be routinely vaccinated against certain cancers.

"We normally vaccinate kids against infectious diseases before they attend school," Johnson said. "We do not have a mind set for vaccinating against cancer.

"But the studies we're doing indicate that in cases where tumors have a clear-cut antigen associated with it, we would immunize people for cancer the way we immunize them to protect against things like polio," he said.

And nothing would please doctors that treat melanoma more than the development of a method of keeping people from coming down with the disease.

"Melanoma is a very aggressive form of skin cancer and prevention or early detection are the two keys to its treatment," said Dr. Robert Skidmore, interim chief of the division of dermatology and cutaneous surgery at Shands at UF health center. "The possibility of preventing this cancer through immunization would be a fantastic way of reducing both morbidity and mortality associated with melanoma.

"It will put me out of business, but that's fine," he said . "I'll find something else to do."

The American Cancer Society predicts that 47,700 people will be diagnosed with melanoma this year and 7,700 of them will die from the disease.
-end-


University of Florida

Related Cancer Articles from Brightsurf:

New blood cancer treatment works by selectively interfering with cancer cell signalling
University of Alberta scientists have identified the mechanism of action behind a new type of precision cancer drug for blood cancers that is set for human trials, according to research published in Nature Communications.

UCI researchers uncover cancer cell vulnerabilities; may lead to better cancer therapies
A new University of California, Irvine-led study reveals a protein responsible for genetic changes resulting in a variety of cancers, may also be the key to more effective, targeted cancer therapy.

Breast cancer treatment costs highest among young women with metastic cancer
In a fight for their lives, young women, age 18-44, spend double the amount of older women to survive metastatic breast cancer, according to a large statewide study by the University of North Carolina at Chapel Hill.

Cancer mortality continues steady decline, driven by progress against lung cancer
The cancer death rate declined by 29% from 1991 to 2017, including a 2.2% drop from 2016 to 2017, the largest single-year drop in cancer mortality ever reported.

Stress in cervical cancer patients associated with higher risk of cancer-specific mortality
Psychological stress was associated with a higher risk of cancer-specific mortality in women diagnosed with cervical cancer.

Cancer-sniffing dogs 97% accurate in identifying lung cancer, according to study in JAOA
The next step will be to further fractionate the samples based on chemical and physical properties, presenting them back to the dogs until the specific biomarkers for each cancer are identified.

Moffitt Cancer Center researchers identify one way T cell function may fail in cancer
Moffitt Cancer Center researchers have discovered a mechanism by which one type of immune cell, CD8+ T cells, can become dysfunctional, impeding its ability to seek and kill cancer cells.

More cancer survivors, fewer cancer specialists point to challenge in meeting care needs
An aging population, a growing number of cancer survivors, and a projected shortage of cancer care providers will result in a challenge in delivering the care for cancer survivors in the United States if systemic changes are not made.

New cancer vaccine platform a potential tool for efficacious targeted cancer therapy
Researchers at the University of Helsinki have discovered a solution in the form of a cancer vaccine platform for improving the efficacy of oncolytic viruses used in cancer treatment.

American Cancer Society outlines blueprint for cancer control in the 21st century
The American Cancer Society is outlining its vision for cancer control in the decades ahead in a series of articles that forms the basis of a national cancer control plan.

Read More: Cancer News and Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.