( ls in the body and not just cancer cell...)Experimental RNA-based drug kills prostate cancer cells effectively and safely

The Duke team set out to produce a drug that would target only cancer cells. To accomplish this goal, the researchers designed a drug that combines two RNA "modules" that work in stages. One module contains targeting RNA, which attaches to a protein, PMSA, found only on the surface of prostate cancer cells. When that module binds to a cancer cell, the cell reacts by engulfing the entire drug molecule.

With the drug now inside the cancer cell, the second module, which contains silencing RNA, launches its effect. The silencing RNA seeks out and binds to the RNA for a specific cancer-causing protein, called PLK1, and tags it for destruction. This eventually leads to the death of the cancer cell.

The researchers first tested the drug in culture dishes containing cancer cells. They found that the drug effectively bound to prostate cancer cells, entered them and shut off production of the target protein, PLK1.

The researchers then moved into mouse experiments. They injected the drug directly into the mice's prostate tumors, administering one injection every two days, for a total of 10 injections over 20 days. By the end of the study, the tumors in the 10 treated mice had shrunk two-fold in volume, while the tumors in the 10 control animals had more than tripled in size.

"The animals themselves showed no signs of side effects," Giangrande said.

The scientists caution that much work remains to move the experimental drug into clinical use in humans. Among the next steps, Sullenger said, is to demonstrate conclusively that the drug can be delivered into the blood stream and still reach the tumor target without being destroyed by the body or causing adverse side effects.