New Drug Protects Against Radiat...( Derivative of protein produced by ba...),Health

Derivative of protein produced by bacteria blocked cell death pathway, study finds

THURSDAY, April 10 (HealthDay News) -- A modified version of a natural intestinal protein has protected animals against the damage caused by the kind of radiation used in cancer therapy, researchers report.

A first human trial of the protective treatment could start later this year, said study co-author Andrei V. Gudkov, senior vice president for basic research at the Roswell Park Cancer Institute in Buffalo, N.Y. The report on the animal trials was published in the April 11 issue of Science.

"This is a version of a protein which is produced by bacteria that are inhabitants of our body," Gudkov explained. "It is made by bacteria to protect normal tissues for their own selfish reasons."

The bacteria survive because the protein, flagellin, prevents intestinal cells from starting the programmed cell death process called apoptosis, he explained. The laboratory-made version of flagellin, designated CBLB502, does the same thing to all cells of the body by temporarily blocking activity of NF-kappaB, a central molecule in the cell death pathway.

Cancer cells are hard to kill, because they lose the apoptosis mechanism when they undergo their transformation to malignancy, and so can grow indefinitely, Gudkov said. "So, we decided to imitate pharmacologically what tumors do genetically," he said.

Like flagellin, CBLB502 does not act directly on apoptosis, he said. Instead, it stimulates cells in the body to make substances that give protection.

A first request for a human trial has been submitted to the U.S. Food and Drug Administration, Gudkov said. The initial use would be in preloaded syringes designed to protect people exposed to radiation in a radioactivity-releasing accident, he said.

A human trial of the drug to limit damage done by radiation treatment of cancer is expected to follow, "we h
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