Gene silencer may improve chemo and radiation

The following news tip is based on abstracts to be presented at the annual meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO), October 19 – 23, 2003 in Salt Lake City, Utah.

Like bacteria that resist common antibiotics, cancer cells can survive chemotherapy and radiation. Radiation oncologists at the Johns Hopkins Kimmel Cancer Center report they have found a gene “silencer” that blocks a cancer cell’s ability to repair itself after drugs and radiation cause damage.

Engineered pieces of protein-encoding RNA (ribonucleic acid), the mirror image of genes’ building blocks, were used to target repair proteins in cancer cells effectively shutting the RNA down. Unable to make the necessary repair proteins, cancer cells then become susceptible to the therapy.

“By dismantling the cancer cell’s machinery to produce these repair proteins, we destroy its ability to withstand toxic chemotherapy and radiation treatments,” says Theodore DeWeese, M.D., director of the Department of Radiation Oncology at the Johns Hopkins Kimmel Cancer Center.

The researchers saw a decrease in the production of targeted repair proteins by approximately 90 percent, and were able to reduce the amount of radiation needed to damage cells.

DeWeese’s research team members are Spencer J. Collis, Ph.D., Michael J. Swartz, and William G. Nelson, M.D., Ph.D.

Embargoed for Release Until Presentation on Monday, October 20th, 10:45 a.m., MT, Salt Palace Convention Center

Johns Hopkins Kimmel Cancer Center
Media Contact: Vanessa Wasta
410-955-1287
E-mail: wastava@jhmi.edu

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