Drug Protects Animals Against Radiation Damage
Activates a mechanism used by cancer cells to avoid death
FRIDAY, April 11 (HealthDay News) -- A drug that activates a cellular pathway used by cancer cells to avoid death can protect against radiation damage and improve survival when given before or after irradiation of mice and primates, researchers report in the April 11 issue of Science.
Lyudmila G. Burdelya, Ph.D., from Roswell Park Cancer Institute in Buffalo, N.Y., and colleagues examined whether CBLB502 (Cleveland BioLabs), a polypeptide drug that binds to Toll-like receptor 5 (TLR5) and activates an anti-apoptotic mechanism used by tumor cells, could protect against the harmful effects of radiation in mouse and primates.
The researchers found that a single injection of CBLB502 before irradiation protected mice from gastrointestinal and hematopoietic acute radiation syndromes and improved survival. CBLB502 also enhanced survival in mice when given after irradiation, but only at lower doses of radiation. The drug was also radioprotective in lethally irradiated rhesus monkeys. The authors note that CBLB502 did not affect the radiosensitivity of tumors in mouse models.
"Thus, TLR5 agonists could potentially improve the therapeutic index of cancer radiotherapy and serve as biological protectants in radiation emergencies," Burdelya and colleagues conclude.