The Scripps Research Institute in La Jolla announced today a discovery of antibodies that can turn leukemia cells against each other, a development that could lead to new cancer therapies.
While studying the effects of antibodies on bone marrow cells, Scripps researchers found that one turned acute myeloid leukemia cells into what they call "natural killer" cells, part of the immune system's rapid reaction force that can be effective against viruses and cancer.
According to TSRI, the scientists observed via electron microscopy that many of the NK cells had extended tendrils through the outer membranes of neighboring leukemia cells. In lab dish tests, a modest number of NK cells wiped out about 15 percent of the surrounding acute myeloid leukemia cell population in just 24 hours.
The scientists — whose study appears in this week's Proceedings of the National Academy of Sciences — said the induced NK cells' cancer-killing effect appeared to be purely fratricidal. The researchers found that unrelated breast cancer cells did not die off in large numbers when in the presence of NK cells.
"It's a totally new approach to cancer, and we're working to test it in human patients as soon as possible," said senior investigator Dr. Richard Lerner, a professor of immunochemistry at TSRI.
Lerner said it's possible that antibodies could be found to produce fratricidal cells in other forms of cancer.
The antibodies would not have to be modified, and should reduce the likelihood of adverse side effects, making them more tolerable for patients than current medications, he said. Also, if the strategy works, fratricidal cells would eliminate all the cancer cells in a patient's body, the scientists said.
Discussions are underway with pharmaceutical companies to bring the therapy to market after further studies are completed, Lerner said.
TSRI said the research was supported by the JPB Foundation, one of the nation's largest philanthropic organizations, along with Zebra Biologics.
