COLUMBUS, Ohio A new study links progression of a lethal type of brain tumor with reduced expression of more than 600 immune system genes, suggesting how complex the immune response is to the cancer and the resulting difficulty in targeting specific immune system proteins for treatment.
Previous research found that people with allergies were less likely to be diagnosed with this type of brain cancer, called glioblastoma multiforme. However, it was not clear whether allergies reduce brain tumor risk or whether the growing tumor "cures" allergies.
To further explore the relationship between these two conditions, scientists examined almost 1,000 genes associated with allergies, immunity and inflammation to learn how they were affected once these tumors were present in the brain.
The researchers expected to see that allergy gene function was low in brain tumor tissue, which would be consistent with the known immune system suppression that is associated with these tumors.
What they found was a surprise: Allergy genes were not the only immune function genes suppressed during tumor growth. Instead, in almost 70 percent of the 919 genes examined, the genes' activity was decreased as the brain tumors progressed.
"This result provides evidence that there is a relationship between glioblastoma and allergies specifically, high tumor aggressiveness is associated with low allergy-related gene function," said Judith Schwartzbaum, lead author of the study and an associate professor of epidemiology at Ohio State University. "But it still does not tell us whether allergies inhibit tumor growth or tumors block allergies."
The findings also show that immune function in the brain continues to change as these tumors grow.
"As the tumor progresses, the majority of the immune-function genes express themselves at lower levels," Schwartzbaum said. "So we know that with progression there is less immune function, but w
|Contact: Judith Schwartzbaum|
Ohio State University