Uncontrolled growth isn’t the only way cancers wreak havoc on the human body. These aggregations of freely dividing cells also release chemicals that can cause damage from a distance. But pinning down how they harm faraway healthy tissues isn’t straightforward.
Fortunately, biologists can turn to the tiny fruit fly to address some of these questions: This insect’s body is not as complex as ours in many ways, but we share important genes and organ functions.
Fruit flies already are a crucial and inexpensive animal for genetics research. Because their life span is about 7 weeks, investigators can track the effects of mutations across several generations in a short period. The animals also are proving useful for learning how chemicals released by malignant tumors can harm tissues in the body that are not near the cancer.
One recent lesson from the fruit flies involves the blood-brain barrier, which determines which molecules gain access to the brain. Researchers at the University of California, Berkeley, have found that malignant tumors in the tiny insects release interleukin 6 (IL-6), an inflammatory chemical that disrupts this important barrier. The investigators showed that the tumors act similarly in mice.
Even if cancer cells persisted, damage related to IL-6 could be diminished.
Fruit flies and mice are only distant relatives of each other and of humans, and the relevance of this discovery to human cancers has not been established. One hurdle is that IL-6 has many important, normal functions related to health. Researchers need to learn how to target only its unwanted blood-brain barrier effects.
A version of this article first appeared on Medscape.com.