Harvard Researchers Isolate Protein Required By Cancer

A Harvard surgeon announced Monday that his research team had isolated a protein without which cancerous tumors revert to a dormant, benign state.

Dr. M. Judah Folkman, Andrus Professor of Pediatric Surgery, told a seminar of the American Cancer Society that the protein--tumor; angiogenesis factor (TAF)--is required by solid tumors to develop capillaries necessary for growth.

Folkman told members of the seminar in Clearwater, Fla, that without the TAF, the tumor becomes trapped in its waste products and is not supplied with the nutrients necessary for growth beyond the size of a pinhead.

The Harvard research team has isolated TAF in both human and animal cancers.

Folkman said that his research team is searching for ways to inhibit the action or prevent the production of TAF. He added that about a half-dozen other laboratories are about to join the search.

The Harvard team is working on the production of an antibody against TAF which might also cause already large tumors--for which surgery is not feasible--to regress. Folkman said.

Folkman--who is also surgeon-in-chief at the Children's Hospital in Boston--said that a treatment method may be in hand within two to five years, and he added that his studies are being adequately funded by the American Cancer Society and the National Cancer Institute.

Folkman pointed out that the only tissues other than solid tumors in which he has found TAF are the placenta and the fetus.

At the same seminar three years ago. Folkman announced that he had discovered that tumors could be held dormant, presumably by a chemical factor.