Novel drug selectively kills prostate cancer cells

By David Douglas

NEW YORK (Reuters Health) – A team of U.S. scientists has
developed an experimental drug treatment that kills prostate
cancer cells in mice while sparing normal cells.

The approach is based on delivering small interfering RNAs
(siRNAs) to tumor cells, North Carolina-based researchers
report in the journal Nature Biotechnology.

In tests in mice with prostate cancer, the researchers
found that tumors treated with the experimental RNA-based drug
had a 2.21-fold reduction in volume. In contrast, various
control tumors left untreated increased in volume by 3.63-fold
over a period of about 2 weeks.

The mice given the RNA-based drug showed no ill effects.

“Our initial animal studies using prostate cancer as a
model are encouraging,” said study investigator Dr. Bruce A.
Sullenger from Duke University Medical Center in Durham, “and
we plan to explore the use of this strategy for targeting a
variety of other cancers and diseases.”

Moreover, he and his colleagues intend to “evaluate the
potential of this approach in … clinical studies in the next
few years.”

Explaining the rationale behind the RNA-based strategy,
Sullenger told Reuters Health: “RNA is such a multifaceted
molecule, that a single molecule of RNA can simultaneously
trick cells into taking it up via a targeting RNA sequence and
shut down the expression of an essential cancer survival gene
via a silencing RNA sequence.”

The approach is a “simple yet elegant” way to target cancer
cells for destruction without harming normal cells, he said.

SOURCE: Nature Biotechnology August 2006.