UCI Team Finds Possible Snag in Cancer Fight

UC Irvine scientists have identified and cloned a substance that appears to block the human body’s natural weapons against cancer tumors.

The protein appears to prevent both white blood cells and a compound produced by the body’s immune system from attacking cancer cells directly, a UCI research team reported today in the journal Cell.

The receptor protein may be blocking the beneficial effects of a new cancer therapy now being tested, research team leader Gale Granger said. The therapy involves injecting cancer patients with the immune system compound known as tumor necrosis factor, or TNF, said Granger, a UCI professor of molecular biology and chemistry. Granger pioneered the discovery of TNF in 1968.

If the protein inhibits the anti-cancer substance when it is injected into cancer patients, “it could be defeating the therapy,” Granger said. “This discovery has changed our approach to the clinical use of (tumor necrosis factor) in cancer patients.”

The role of the protein blocker, found in the bloodstream of cancer patients and in both cancer and normal cells, is not fully understood, Granger said. One possibility is that normal cells produce the chemical to balance or control the cancer-killing substance in the body.

If, however, it is being released into the bloodstream by cancer cells, “then cancer has found a way to fight the immune system, which is a frightening thought,” he said.