TUESDAY, April 17, 2007 (HealthDay News) -- U.S. scientists say they've developed a breast cancer vaccine that stimulates a powerful immune system response to tumor cells.
In mice, the "synthetic peptide" vaccine stimulated an anti-tumor T-cell response that identified and prevented the spread of breast cancer cells. T-cells are white blood cells that play an important role in immune response.
A team at the Mayo Clinic in Rochester, Minn., tested the vaccine on female mice that had the cancer-producing oncogene HER-2/neu. The mice received the vaccine at the early stage of tumor development.
The vaccine either slowed or stopped the progression of breast cancer in all the mice, the team reported Tuesday at the annual meeting of the American Association for Cancer Research in Los Angeles.
Because synthetic peptides alone do not usually trigger a strong immune response, the vaccine was given in combination with a "Toll-like receptor" stimulant, which mimics the way invading bacteria would spur the immune system into action.
"We found that we could train the immune system to recognize these synthetic peptides as dangerous foreign agents of the HER-2/neu gene by mimicking what the bacteria would do in your body. The body responded by killing everything that expressed HER-2/neu in high amounts," study author Dr. Pilar Nava-Parada said in a prepared statement.
Using this approach, it would likely take only one immunization to build an immune system response powerful enough to destroy a tumor.
To date, attempts at creating effective cancer vaccines have produced mixed results. This and other new studies suggest that scientists are moving closer to creating viable cancer vaccines, the Mayo researchers said.
The U.S. National Cancer Institute has more about cancer vaccines.