Researchers receive $2 million grant to study radiation toxicity 

Jim Goodwin

By Cynthia Marich

Dennis Hallahan, MD


Girdhar Sharma, PhD

March 4, 2013 - Cancer biology investigators at Washington University School of Medicine and the Siteman Cancer Center have been awarded a five-year $2 million grant to study the radiosensitivity of normal stem cells in organs that are damaged during radiotherapy. 

Dennis Hallahan, MD, the Elizabeth H. and James S. McDonnell III Distinguished Professor and head of radiation oncology, is one of two principal investigators for the grant from the National Cancer Institute. He is collaborating with Girdhar Sharma, PhD, assistant professor of radiation oncology, to develop prevention and intervention strategies for protecting healthy tissues during cancer therapy.

Radiation therapy can be curative but often lifestyle-limiting. Hallahan and Sharma seek to assess the sensitivity of normal stem cells to understand the biological basis of toxicity. By characterizing the different types of radiation sensitivity, the study aims to provide strategies to protect healthy stem cells and maintain normal organ function throughout the lifetime of cancer survivors. 

"One of the challenges of radiotherapy is the unavoidable toxicities," Hallahan says. "In this study, we seek to identify new ways to protect normal (non-cancer) cells." 

The team will also identify way to protect normal tissues with inhibitors of enzymes in normal cells but not cancerous cells. One such strategy with Cliff Robinson, MD, assistant professor of radiation oncology, is being studied in patients at Siteman. 

"Radiation therapy causes toxicity, which impairs the quality of life in cancer survivors," Hallahan says. "For example, a child with a brain tumor is left with memory loss, which may to lead to learning disorders and unemployment as an adult.

"We now have more than 10 million cancer survivors in the United States alone," he adds. "We need to understand how to protect healthy cells to improve their long-term quality of life."