Berkeley - Insertion of a single gene into several different tumors enabled mice to reject them all, leading scientists at the University of California, Berkeley, to hope that the gene might form the basis for a vaccine effective against a range of cancers.
This simple gene therapy also protected the mice against subsequent injection of tumor cells that had not been altered, meaning their immune systems remembered the initial challenge - a necessary step for any vaccine therapy.
"When we introduced the gene into cells that didn't have it and then injected the tumor cells into mice, they clearly stimulated a variety of different elements of the immune system, including natural killer cells and killer T cells," said David H. Raulet, the Choh Hao Li Professor of Immunology in the College of Letters & Science at UC Berkeley. "The response in mice was really very dramatic and unexpected - the tumors were all uniformly rejected."
He is optimistic that the gene - actually two families of similar genes - will make an effective vaccine therapy, joining the growing arsenal of cancer immunotherapies in clinical trials today.
Raulet, along with UC Berkeley postdoctoral fellow Andreas Diefenbach, graduate student Amanda M. Jamieson and postdoctoral fellow Eric R. Jensen, report the findings in the Sept. 13 issue of Nature. All are part of the campus's Health Sciences Initiative.
The findings hark back to a theory popular a generation ago - that the immune system constantly surveys the body for cancer cells and kills them on sight. Only when the growth of cancer cells outstrips the immune system's ability to eliminate them do tumors form. The idea fell by the wayside when scientists found that most cancers were no more common in mice lacking certain components of the immune system than in normal mice. More recent studies, however, suggest that the mice used in the first reports were not entirely immunodeficient, and that cancer is indeed
Contact: Robert Sanders
University of California - Berkeley