Vaccine kills breast cancer in mice
Researchers have developed a vaccine that destroys breast cancer tumors that mimic human cancer in a mouse model. The scientists, from the University of Georgia and the Mayo Clinic in Arizona, say the vaccine teaches the immune system to recognize and attack cancer cells based on their structure.
The vaccine might also work for ovarian and colorectal cancers, according to the findings published in the Proceedings of the National Academy of Sciences.
"This vaccine elicits a very strong immune response," said study co-senior author Geert-Jan Boons, Franklin Professor of Chemistry and a researcher in the UGA Cancer Center and its Complex Carbohydrate Research Center. "It activates all three components of the immune system to reduce tumor size by an average of 80 percent."
For their study, researchers used mice that were specially bred to overexpress a protein known as MUC1 that has a distinct sugar structure and differs from healthy cells.
In mice the vaccine dramatically shrank tumors in the mouse model that imitates 90 percent of human breast cancer ,even those that are resistant to standard breast cancer therapy.
An example is “triple negative” tumors that are aggressive and hard to treat. The study authors say new therapies are urgently needed.
"In the U.S. alone, there are 35,000 patients diagnosed every year whose tumors are triple-negative," Boons said. "So we might have a therapy for a large group of patients for which there is currently no drug therapy aside from chemotherapy."
Sandra Gendler, Grohne Professor of Therapeutics for Cancer Research at the Mayo Clinic in Arizona and senior study co-author explains when healthy cells mutate and become cancerous, overexpression of MUC1 leads to tumors.
Unlike the prostate cancer vaccine Provenge, the breast cancer vaccine is easy to manufacture and is synthetic, consisting of an immune system booster known as an adjuvant, a component that activates T-helper cells to produce immunity, and a carbohydrate-linked peptide molecule that directs the immune response to cells bearing MUC1 proteins with short chains of carbohydrates.
"We are beginning to have therapies that can teach our immune system to fight what is uniquely found in cancer cells," Boons said. "When combined with early diagnosis, the hope is that one day cancer will become a manageable disease."
The vaccine to fight breast cancer and perhaps pancreatic and colorectal cancers took a decade of research. The scientists hope the mouse findings will translate to humans.
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