Tumor cell 'destruct triggers' studied

Gainesville, Fla -- U.S. geneticists say tumor cells might be able to escape death from radiation or chemotherapy because of a blockage in their self-destruct mechanisms.

University of Florida researchers studying fruit fly cells discovered that slight changes in the protein scaffolds supporting the genes "reaper" and "hid" cause the cells to become naturally resistant to X-rays during early development.

"It turns out that a piece of DNA that is required for mediating this process of cell death is blocked," Associate Professor Lei Zhou. "When it is blocked, the cells just don't die, even when subjected to heavy doses of radiation. This may be what is happening in some resistant cancer cells. The pro-apoptotic genes cannot be induced to cause cell death."

The researchers said their findings might be the first to link apoptosis -- the gene-driven process that leads to the necessary destruction of old, damaged, or infected cells -- with epigenetics, the study of how gene function changes even when the genes themselves don't change.

The research was reported in a recent issue of the journal Developmental Cell.