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Prostate cancer is often treated by perturbing androgen receptor signalling. CACNA1D, encoding CaV1.3 ion channels is upregulated in prostate cancer. Here we show how hormone therapy affects CACNA1D expression and CaV1.3 function. Human prostate cells (LNCaP, VCaP, C4-2B, normal RWPE-1) and a tissue microarray were used. Cells were treated with anti-androgen drug, Enzalutamide (ENZ) or androgen-removal from media, mimicking androgen-deprivation therapy (ADT). Proliferation assays, qPCR, Western blot, immunofluorescence, Ca2+-imaging and patch-clamp electrophysiology were performed. Nifedipine, Bay K 8644 (CaV1.3 inhibitor, activator), mibefradil, Ni2+ (CaV3.2 inhibitors) and high K+ depolarising solution were employed. CACNA1D and CaV1.3 protein are overexpressed in prostate tumours and CACNA1D was overexpressed in androgen-sensitive prostate cancer cells. In LNCaP, ADT or ENZ increased CACNA1D time-dependently whereas total protein showed little change. Untreated LNCaP were unresponsive to depolarising high K+/Bay K (to activate CaV1.3); moreover, currents were rarely detected. ADT or ENZ-treated LNCaP exhibited nifedipine-sensitive Ca2+-transients; ADT-treated LNCaP exhibited mibefradil-sensitive or, occasionally, nifedipine-sensitive inward currents. CACNA1D knockdown reduced the subpopulation of treated-LNCaP with CaV1.3 activity. VCaP displayed nifedipine-sensitive high K+/Bay K transients (responding subpopulation was increased by ENZ), and Ni2+-sensitive currents. Hormone therapy enables depolarization/Bay K-evoked Ca2+-transients and detection of CaV1.3 and CaV3.2 currents. Physiological and genomic CACNA1D/CaV1.3 mechanisms are likely active during hormone therapy—their modulation may offer therapeutic advantage.

DJ-1 was first identified as a novel candidate of an oncogene product in cooperation with an activated ras, and DJ-1 was later found to be a positive regulator of the androgen receptor (AR) transcription activity that was repressed by PIASxalpha. DJ-1 was also found to be an infertility-related protein that was reduced in rat sperm treated with sperm toxicants that cause infertility in rats. To determine the roles of DJ-1 in the AR function, the effects of several androgen antagonists, some of which had been identified as endocrine-disrupting chemicals, on AR transcription activity and localization of AR and DJ-1 in Cos7 cells were examined. Co-localization of DJ-1 with the AR as dot-like spots in the nucleus was first found in cells that had not been treated with chemicals. Although all of the chemicals tested inhibited AR transcription activity to an average of 25% of that without chemicals, there were two classes affecting the localization of the two proteins; one changes the AR from dot-like spots to diffuse spaces in the nucleus and the other still keeps the AR in the dot-like spots. The localization of DJ-1, on the other hand, was found to be dramatically changed by all of the chemicals, resulting in loss of co-localization with the AR. These results indicate that DJ-1 is an essential factor for the AR to exert its full activity.