Androgen deprivation may encourage prostate cancer spread

Androgen deprivation therapy may encourage prostate cancer cells to produce a protein that makes them more likely to spread throughout the body, suggests a new study by researchers at Johns Hopkins University School of Medicine, Baltimore. Although the finding could eventually lead to changes in this standard treatment for prostate cancer, the researchers caution that their discovery is far too preliminary for patients or physicians to stop using hormone therapy.

David Berman, MD, and colleagues identified the unsuspected potential problem after discovering that the gene that codes for the protein, called nestin, was active in lab-grown human prostate cancer cells.

The researchers looked for nestin in cells taken from men who had had surgery to remove locally confined prostate cancers and found none. But when they looked for nestin in prostate cancer cells isolated from patients who had died of metastatic disease, they found substantial evidence that the nestin gene was active (Cancer Res 2007; 67:9199-206).

Aware that the nestin gene has long been suggested as having a role in cell growth and development, the team used RNA interference to decrease the genetic expression of nestin and found that these cells were not able to move around and through other cells nearly as well as cells with normal nestin levels were.

Prostate cancer cells with hampered nestin expression were also less likely than were normal prostate cancer cells to migrate to other parts of the body when transplanted into mice.

“What all this suggests is that nestin levels increased when prostate cancer cells are deprived of androgens and may encourage the cells to metastasize,” Dr. Berman said.