Editor’s Note: This article was written and submitted by Rich Halberg, PhD, and Chris Malina, senior communications specialist at the University of Wisconsin Carbone Cancer Center.
Ongoing space radiation research – including contributions from one Princeton, Wisconsin native – is helping NASA better understand the cancer risk associated with interplanetary space travel.
Rich Halberg, PhD, is the son of Dick and Sandee Halberg, and graduated from Princeton High School in 1983. He has worked as an associate professor in the departments of medicine and oncology at the University of Wisconsin (UW) in Madison, and is a member of the UW Carbone Cancer Center. He was recently promoted to become the inaugural Senior Director of School Of Medicine and Public Health Biomedical Research Cores.
For nearly two decades, Halberg has worked with Jeff Bacher, PhD, at the Promega Corporation. The two have collaborated on several NASA-funded projects with an emphasis on space radiation.
Without an atmosphere for protection, astronauts are more exposed to high-energy radiation from the sun and other sources; however, the effect of this radiation on humans, and how it varies from person-to-person, isn’t fully understood.
To study this, Halberg and Bacher traveled to the NASA Space Radiation Laboratory in Brookhaven, N.Y. to simulate the effect of this radiation, in a controlled environment, using mice.
Previous studies have shown that exposure to this high-energy radiation causes tumors in mice. Many of these studies have also suggested these tumors would be much more aggressive, or metastasize to other sites in the body.
But in their latest study, published in the “International Journal of Radiation Biology,” Halberg and Bacher found that hypothesis didn’t exactly hold up when it came to liver tumors, in particular.
“The radiation still induced liver tumors, but it didn’t induce more aggressive tumors,” Halberg said. “We did see a slight increase in the number of tumors that formed, but they were not any more aggressive than tumors that had formed after exposure to this low energy radiation, or just those that spontaneously formed.”
While additional studies targeting other cancer types will likely need to come next, Halberg says his study had an unexpected benefit: the mouse model developed for the project actually turned out to be a good model for understanding liver cancer in humans.
“Many of the molecular features of the tumor, and many of the clinical tests that would be run, our mouse models actually mimicked what would happen in the clinic essentially,” he said.
One example of that involves a protein called alpha-fetoprotein, which is considered a biomarker for liver cancer in humans. In their research, Halberg and Bacher collected blood samples from the mice as they were aging. They found that not only could the protein also be detected in mouse blood, but it could also predict which mice were likely to develop liver cancer in the future.
Throughout their now five grants together, both Halberg and Bacher have frequently found themselves in “spin-off” studies, using their models and markers to explore things like personalized doses of radiation, the effect of multiple CT scans on cancer risk and better predicting which patients might have a better response to certain immunotherapy drugs.
So even if humans aren’t heading to Mars anytime soon, this research could have a much more immediate impact, and arguably in a more important place: right here on Earth.