The findings mark the two proteins, Heat shock protein (Hsp) 70.1 and 70.3, as potential targets for gene therapy that could increase cancer cells' vulnerability to treatments.
"This is the first time we've linked these proteins to the cancer cell's response to ionizing radiation," says Tej Pandita, Ph.D., assistant professor of radiation oncology and lead investigator of the new study. "Understanding the pathobiology of the genes that make these proteins -- how they function in normal circumstances and how they work in an unusual context like the cancer cell -- will help radiation oncologists devise gene therapy protocols that enhance cell kill from radiation treatments."
The findings will appear in the second January 2004 issue of Molecular and Cellular Biology (volume 24, issue 2), which will be available online on Dec. 28.
All cancers are caused to some degree by loss of genetic stability, according to Pandita. Genetic instability provides a chance for regulation of cell growth, cell division or other important processes to slip out of control, allowing a cancer to get its start. But too much genetic instability, a potential risk during the rapid and repeated cell division that is a hallmark of cancer, can increase vulnerability to stress and the chance that cells will self-destruct.
Pandita studies telomerase, an enzyme that helps maintain the telomeres, structures at the ends of chromosomes. Healthy cells normally only make telomerase when they're preparing to divide and need the enzyme to stabilize the telomeres in preparation for replication of the genetic material. In cancer
Contact: Michael C. Purdy
Washington University School of Medicine