Tanja[a]
Journal of the National Cancer Institute 2001;93:1553-1557
DNA Repair Defect May Lead to Brain Tumor
Researchers have discovered a defect in the body´s natural DNA repair mechanisms that may cause a deadly form of brain tumor called malignant glioma.
Lead investigator Dr. Melissa L. Bondy of the University of Texas in Houston
told Reuters Health that patients with the brain cancer were twice as likely
to have poor DNA repair capacity.
In the study, the researchers exposed blood samples from 219 patients who
were diagnosed with glioma and 238 healthy individuals to a kind of
radiation known as gamma radiation. Then they counted the number of "breaks"
in DNA after the cells should have had enough time to repair themselves,
Bondy explained. Patients with glioma were two times more sensitive to gamma
radiation-induced DNA breaks than patients without the disease, according to
the report in the October 17th issue of the Journal of the National Cancer
Institute
"Our findings confirm that the sensitivity to gamma radiation and the
subsequent inability to repair radiation-induced DNA damage may increase the
risk for (tumor formation)," Bondy and colleagues conclude.
"These findings suggest that a measurable DNA repair defect may underlie the
formation of gliomas," Dr. Kenneth J. Dornfeld and Theodore S. Lawrence of
the University of Michigan in Ann Arbor write in an accompanying editorial.
They note that breast, colon, and neck cancers are also associated with such
defects.
Malignant glioma is an aggressive type of brain cancer that does not respond
well to treatment. Most people with the disease die within a year of being
diagnosed..