Durham, N.C. -- Acting as a genetic Trojan horse, an experimental RNA-based drug -- the first of its kind -- tricks its way into prostate cancer cells and then springs into action to destroy them, while leaving normal cells unarmed.

The drug, developed at Duke University Medical Center, uses one type of genetic material, called targeting RNA, to enter cancer cells, and another type, called silencing RNA, to stop the expression of a protein that keeps the cells alive.

In tests in mice with prostate cancer, the drug shrank the size of their tumors by half, while the tumors in control mice that did not receive the drug continued to grow, said study co-author Bruce Sullenger, Ph.D., director of Duke's Translational Research Institute and chief of the Division of Experimental Surgery.

The mice showed no side effects from the treatment, Sullenger said.

"This study represents the first step in creating an RNA-based drug for cancer," said lead author James McNamara, Ph.D. a postdoctoral fellow in experimental surgery. "It provides a 'proof of principle' that an entirely RNA-based drug can work with minimal side effects, and it shows it is possible to overcome many of the obstacles that have hampered the development of RNA-based drugs."

The study is reported in the August 2006 issue of Nature Biotechnology, which is now available online. The research was funded by the National Institutes of Health.

Duke has filed a provisional patent application on the technology, according to the researchers.

"Scientists have made numerous attempts to transform silencing RNAs into natural anticancer agents, but such development has been challenging," said Paloma Giangrande, Ph.D., co-leader of the study and an assistant research professor in experimental surgery.

Scientists have encountered major obstacles when trying to deliver silencing RNAs to tumors, Giangrande said. Previous RNA-based drugs have been no
'"/>

Contact: Marla Vacek Broadfoot
marla.broadfoot@duke.edu
919-660-1306
Duke University Medical Center
10-Aug-2006