DJ-1 Binds Androgen Receptor Directly and Mediates Its Activity in Hormonally Treated Prostate Cancer Cells

The oncogene DJ-1 has been associated with multiple cancers, including prostate cancer, where it can be stabilized by androgens and antiandrogens. However, little data exist on the expression pattern and function of DJ-1 in prostate cancer. To address the function of DJ-1 in prostate, a yeast two-hybrid screen was done to identify novel DJ-1 binding proteins. The androgen receptor (AR) was identified and confirmed as a DJ-1 binding partner. This is the first evidence that DJ-1 directly interacts with AR. We also show that modulation of DJ-1 expression regulated AR transcriptional activity. Importantly, both the subcellular localization of DJ-1 and the interaction with AR are regulated by androgens and antiandrogens. Additionally, immunohistochemical staining on two human prostate cancer tissue arrays was done providing the first large-scale expression analysis of DJ-1 in prostate. DJ-1 expression did not change with Gleason pattern but increased after androgen deprivation therapy, indicating that it may be involved in the development of androgen independence. These data provide a novel mechanism where DJ-1-mediated regulation of AR may promote the progression of prostate cancer to androgen independence.