Amplification and co-regulators of androgen receptor gene in prostate cancer.

Prostate cancer is the second most common malignancy among males after lung cancer. The growth of prostate cancer cells depends on the presence of androgens, a group of steroid hormones that include testosterone and its more active metabolite dihydrotestoste-rone. Most prostate cancers are androgen-dependent and respond to the antiandrogens or androgen-deprivation therapy. However, the progression to an androgen-independent stage occurs frequently. Possible mechanisms that could be involved in the development of hormone resistant prostate cancer causes including androgen receptor (AR) mutations, AR amplification/over expression, interaction between AR and other growth factors, and enhanced signaling in a ligand-independent manner are discussed.