Androgen-Deprivation Therapy May Encourage Prostate Cancer

A new study suggests that androgen-deprivation therapy (ADT), the reduction of male hormones levels in the body, may encourage prostate cancer cells to metastasize.

Researchers from the Johns Hopkins University School of Medicine (Baltimore, MD, USA) examined cells taken from 254 men who had surgery to remove locally confined cancers of the prostate, looking for traces of nestin--a type VI intermediate filament (IF) protein. The researchers found that none of the specimens contained nestin; however, when they looked for the protein in prostate cancer cells isolated from patients who had died of metastatic prostate cancer, they found evidence that the nestin gene was active.

The researchers speculated that depriving cells of androgens might affect nestin expression. To explore this, they experimented on a prostate cancer cell line that depends on androgens to grow. When they removed androgens from the chemical mixture that the cells live in, the production of nestin increased. The investigators also found that prostate cancer cells with impaired nestin expression were less likely than normal prostate cancer cells to migrate to other parts of the body when transplanted in mice. But while nestin expression seemed pivotal for metastasis in these experiments, the researchers note, it did not seem to make a difference in tumor growth. The study was published in the October 1, 2007, issue of Cancer Research.

"Our data indicate that in a significant proportion of prostate cancers, nestin expression is required for colonizing distant sites in metastasis and thus may be a marker of metastasis-initiating cancer stem cells,” concluded lead author by Wolfram Kleeberger, M.D., and colleagues

The main androgens are testosterone and dihydrotestosterone (DHT). The researchers caution that their finding is far too preliminary to recommend altering treatment, and that they do not expect to find a problem with the popular testosterone-suppressing treatments.


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Johns Hopkins University School of Medicine