New drug protects mice from toxic effects of radiation
By Karen Sprey
June 28, 2010
Radiation is a frontline treatment for many cancers. However, its therapeutic value can come at the cost of damage to the bone marrow which produces all of the body's red and white blood cells and platelets, so finding ways to protect bone marrow is a research priority. A study by the UNC Lineberger Comprehensive Cancer Center has shown that the drug PQ can successfully protect mice from lethal doses of radiation.
Researchers hope PQ will be able to protect humans who are exposed to high doses of radiation, either intentional, such as cancer patients, or accidental – for example, disaster victims.
PQ (pharmacological quiescence) inhibits enzymes involved in cell division and temporarily prevents some types of bone marrow cells from dividing. it has been known for several decades that cells which don't divide are resistant to agents such as radiation that damage DNA, but this is the first successful example of radiomitigation in mammals.
Mice that were given PQ orally immediately before or up to 20 hours after exposure to radiation showed normal counts of red and white blood cells and platelets.
"We have identified a simple, non-toxic pill that decreases radiation toxicity even when given after radiation exposure," said Norman Sharpless, UNC Lineberger Associate Director for Translational Research and an associate professor of medicine and genetics at UNC’s School of Medicine.
"We believe this approach could be of use in humans who are accidentally or intentionally exposed to lethal doses of radiation”.
Drugs such as PQ can be given as a pill, are chemically stable and have little toxicity so they could be stockpiled for use in the event of a radiological disaster.
PQ may also provide protection from bone marrow toxicity caused by chemotherapy drugs.