UT Southwestern researchers reported a first-time discovery regarding DNA sensors and cancer. They found that tumors stressed by cancer immunotherapy release DNA sensors via mitochondria into nearby cells to trigger an alert system.
According to a UT Southwestern study, the chemical alarm is an important immune-system sensor for DNA because it is found in the cytosol, the interior of cells where DNA normally does not exist.
The study states this alarm plays a critical role in bridging the body’s two immune systems: the innate immune system, which senses initial threats; and the adaptive immune system, which triggers an anti-tumor response after getting the alert from the innate immune system. This was identified by co-author Dr. Zhijian James Chen, professor of molecular biology at UT Southwestern.
“These findings help lead to strategies to making a newly created anti-cancer treatment, immune checkpoint blockade therapy, more effective,” Dr. Yang-Xin Fu, senior author of the study, said. The checkpoints are barriers cancer cells produce to make themselves “undetectable” to the immune system. This treatment allows cancer cells to be detected.
Fu told D CEO Healthcare: “Most of us think that anti-cancer drugs and radiation directly kill tumor cells but our studies show that those treatments’ anti-tumor effects depend on host immune responses. Those treatments induce tumor stress that causes the DNA release that triggers the immune response. We might have underestimated the potency of mitochondric DNA for triggering immune responses.”