The Bilder Lab, led by campus molecular and cell biology professor David Bilder, recently discovered analyzing fruit flies can inform researchers about human cancer survival.
Bilder, joined by postdoctoral researcher Jung Kim, analyzed the effects of cancerous tumors on flies to discern whether fly models can inform potential human cancer treatments. The study was published in the journal Developmental Cell Sept. 7.
“Flies can get tumors like humans can,” Kim said in an email. “Although flies and humans have some obvious differences, they are more similar genetically and in terms of biology than most people would think.”
Kim added that after joining the Bilder Lab, he investigated the effect of tumor-dependent cachexia — loss of skeletal muscle due to tumors — on fly lifespans. This research led him to search for other tumor effects in flies and inspired the recent study.
In the study, the Bilder Lab found tumor-secreted substances disrupted flies’ blood-brain barrier, or BBB, according to Kim. Kim said the BBB protects most animals, such as mice, humans and flies, from the circulation of toxins or pathogens in the brain.
The Bilder Lab also worked with the labs of campus professors David Raulet and Kaoru Saijo, where phenotypes seen in flies were also observed in mice, according to Kim.
“Blocking the effect of the tumor-secreted factor on the barrier in tumor-bearing hosts extended lifespan in both flies and mice,” Kim said in an email. “Therefore, the BBB normally protects both mice and flies from tumor-induced death.”
Raulet said with the help of campus graduate student Natalie Wolf, his lab generated tumors in the mice and collected blood samples to figure out whether the protein interleukin 6, or IL-6, was increasing, and to determine whether or not it was associated with the opening of the BBB.
After finding out generating tumors increased IL-6 and contributed to the decline in the mice’s health, Raulet noted that the “key experiment” in the study was when Wolf injected ANTI-IL-6 antibodies into the mice, discovering animals will survive longer if IL-6 is blocked.
“This provided evidence that this discovery made by (David Bilder’s) group has relevance for mammals — in this case, mice,” Raulet said.
Specifically, the Bilder study showed cancer-carrying flies’ median lifespan increased by 45% when IL-6 activity was blocked at the BBB, according to the study.
In the future, Raulet said his lab may continue to analyze IL-6, as blocking the protein alleviates suffering and could potentially extend lifespans for those with terminal cancer.
Kim added that a rewarding moment in the study was seeing the consistent data shown in Raulet’s experiment.
“I was shocked, like ‘oh, my study can be translated to other model organisms,’” Kim said. “I was so excited by that.”
Kim concluded that his “small hope” is that the study will contribute to understanding human health.