Next, the Duke team tried the approach in mice using three different solutions of cells in animals undergoing bone marrow transplants. One group received regular bone marrow cells; a second group got bone marrow cells from donors that had been irradiated and treated with EGF; a third group got bone marrow cells from irradiated donors treated with saline.
The regular bone marrow cells proliferated well and had the highest rate of engraftment in the recipient mice. But mice that were transplanted with the cells from irradiated/EGF-treated donors had 20-fold higher engraftment rate than the third group.
Additional studies showed that EGF improved survival from a lethal radiation exposure, with 93 percent of mice surviving the radiation dose if they subsequently received treatment with EGF, compared to 53 percent surviving after treatment with a saline solution.
Chute said it appears that EGF works by repressing a protein called PUMA that normally triggers stem cell death following radiation exposure.
"We are just beginning to understand the mechanisms through which EGF promotes stem cell regeneration after radiation injury," Chute said. "This study suggests that EGF might have potential to accelerate the recovery of the blood system in patients treated with chemotherapy or radiation."
|Contact: Sarah Avery|
Duke University Medical Center