March 22, 2002

MGH scientists have discovered that herceptin, a monoclonal antibody used to fight certain forms of breast cancer, can stop the growth of new blood vessels. Herceptin is known to block the cell receptor HER2 on breast cancer cells and is used to treat women whose tumors produce extra copies of the receptor, which causes a more aggressive form of cancer. In the March 21 issue of Nature, researchers from the MGH Department of Radiation Oncology show that herceptin also can reduce the diameter and volume of tumor blood vessels, slow tumor growth and prolong survival in animal models of cancer.

"The beauty of this molecule is that it has multiple anti-angiogenic effects and so it acts like a cocktail of angiogenesis-blocking drugs," says Rakesh Jain, PhD, (right), director of the MGH Steele Laboratory for Tumor Biology, and the report's senior author. Researchers have been trying for years to block a tumor's ability to secrete factors that create new blood vessels and give cancer access to supplies of blood and oxygen. When one of these angiogenic factors is successfully blocked, however, the cancer cells can adapt and secrete other factors. Jain and his team have found that herceptin can target at least five factors, thereby thwarting the cancer cells' tactics.

Jain sees great promise for herceptin and similar agents in the future. "Someday we may have detailed profiles of individual patients and their tumors, and we'll know which genes and angiogenic factors need to be targeted," he says. "By identifying other antibodies or inhibitors like herceptin, we may be able to tailor treatments through multiple cocktail therapies." The other members of the MGH research team are Yotaro Izumi, MD, PhD, first author; Lei Xu, MD, PhD; Emmanuelle di Tomaso, PhD; and Dai Fukumura, MD, PhD, all of the Steele Lab.