NEW YORK: In what is claimed to be a first, researchers have discovered how genes get "shut down" in cancer cells, raising the possibility of new treatment options that switch them back on.

The study, by researchers at the University of Southern California, has identified how genes are "silenced" in cancer cells through changes in the density of nucleosomes within the cells. The findings of the study are published in forthcoming issue of the journal Cancer Cell. According lead author Peter A Jones, the study shows "for the first time exactly how genes get shut down in cancer cells... It identifies what the target looks like so that new therapies can be designed to turn them back on." The study showed that silencing of transcription start sites in some cancer cells involves distinct changes in the density of nucleosomes in the cell.

"We believe these findings will contribute to the development of cancer therapies... We were surprised to find how rigid the inactive structure is, and how rapidly it can be dissolved by drug treatment," Jones said.