1-7-bis(4-hydroxy-3-methoxyphenyl)-1-4-6-heptatrien-3-one and Neoplasm-Metastasis

Despite the fact that androgen deprivation therapy (ADT) can effectively reduce prostate cancer (PCa) size, its effect on PCa metastasis remains unclear. We examined the existing data on PCa patients treated with ADT plus anti-androgens to analyze ADT effects on primary tumor size, prostate-specific antigen (PSA) values, and metastatic incidence. We found that the current ADT with anti-androgens might lead to primary tumor reduction, with PSA decreased yet metastases increased in some PCa patients. Using in vitro and in vivo metastasis models with four human PCa cell lines, we evaluated the effects of the currently used anti-androgens, Casodex/bicalutamide and MDV3100/enzalutamide, and the newly developed anti-AR compounds, ASC-J9® and cryptotanshinone, on PCa cell growth and invasion. In vitro results showed that 10 μm Casodex or MDV3100 treatments suppressed PCa cell growth and reduced PSA level yet significantly enhanced PCa cell invasion. In vivo mice studies using an orthotopic xenograft mouse model also confirmed these results. In contrast, ASC-J9® led to suppressed PCa cell growth and cell invasion in in vitro and in vivo models. Mechanism dissection indicated these Casodex/MDV3100 treatments enhanced the TGF-β1/Smad3/MMP9 pathway, but ASC-J9® and cryptotanshinone showed promising anti-invasion effects via down-regulation of MMP9 expression. These findings suggest the potential risks of using anti-androgens and provide a potential new therapy using ASC-J9® to battle PCa metastasis at the castration-resistant stage.

Topics: Androgen Receptor Antagonists; Androgens; Anilides; Animals; Benzamides; Cell Line, Tumor; Curcumin; Down-Regulation; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Humans; Male; Matrix Metalloproteinase 9; Mice; Mice, Nude; Neoplasm Invasiveness; Neoplasm Metastasis; Neoplasm Proteins; Neoplasm Transplantation; Neoplasms, Experimental; Nitriles; Phenylthiohydantoin; Prostate-Specific Antigen; Prostatic Neoplasms; Smad3 Protein; Tosyl Compounds; Transforming Growth Factor beta1; Transplantation, Heterologous; Xenograft Model Antitumor Assays

Androgen deprivation therapy (ADT) with the newly developed powerful anti-androgen enzalutamide (Enz, also known as MDV3100) has promising therapeutic effects to suppress castration resistant prostate cancer (CRPC) and extending patients' lives an extra 4.8 months. However, most Enz therapy eventually fails with the development of Enz resistance. The detailed mechanisms how CRPC develops Enz resistance remain unclear and may involve multiple mechanisms. Among them, the induction of the androgen receptor (AR) mutant AR-F876L in some CRPC patients may represent one driving force that confers Enz resistance. Here, we demonstrate that the AR degradation enhancer, ASC-J9(®), not only degrades wild-type AR, but also has the ability to target AR-F876L. The consequence of suppressing AR-F876L may then abrogate AR-F876L mediated CRPC cell proliferation and metastasis. Thus, developing ASC-J9(®) as a new therapeutic approach may represent a novel therapy to better suppress CRPC that has already developed Enz resistance.

Topics: Androgen Antagonists; Antineoplastic Agents, Hormonal; Benzamides; Cell Line, Tumor; Cell Movement; Cell Proliferation; Curcumin; Drug Resistance, Neoplasm; Humans; Male; Mutation; Neoplasm Metastasis; Nitriles; Phenylthiohydantoin; Prostatic Neoplasms, Castration-Resistant; Proteolysis; Receptors, Androgen; Signal Transduction; Time Factors; Transcription, Genetic; Transfection

Despite androgen deprivation therapy (ADT) suppression of prostate cancer (PCa) growth, its overall effects on PCa metastasis remain unclear. Using human (C4-2B/THP1) and mouse (TRAMP-C1/RAW264.7) PCa cells-macrophages co-culture systems, we found currently used anti-androgens, MDV3100 (enzalutamide) or Casodex (bicalutamide), promoted macrophage migration to PCa cells that consequently led to enhanced PCa cell invasion. In contrast, the AR degradation enhancer, ASC-J9, suppressed both macrophage migration and subsequent PCa cell invasion. Mechanism dissection showed that Casodex/MDV3100 reduced the AR-mediated PIAS3 expression and enhanced the pSTAT3-CCL2 pathway. Addition of CCR2 antagonist reversed the Casodex/MDV3100-induced macrophage migration and PCa cell invasion. In contrast, ASC-J9 could regulate pSTAT3-CCL2 signaling using two pathways: an AR-dependent pathway via inhibiting PIAS3 expression and an AR-independent pathway via direct inhibition of the STAT3 phosphorylation/activation. These findings were confirmed in the in vivo mouse model with orthotopically injected TRAMP-C1 cells. Together, these results may raise the potential concern about the currently used ADT with anti-androgens that promotes PCa metastasis and may provide some new and better therapeutic strategies using ASC-J9 alone or a combinational therapy that simultaneously targets androgens/AR signaling and PIAS3-pSTAT3-CCL2 signaling to better battle PCa growth and metastasis at castration-resistant stage.

Topics: Androgen Antagonists; Androgen Receptor Antagonists; Anilides; Animals; Antineoplastic Agents; Benzamides; Cell Movement; Chemokine CCL3; Coculture Techniques; Curcumin; Humans; Macrophages; Male; Mice; Neoplasm Metastasis; Nitriles; Phenylthiohydantoin; Prostatic Neoplasms; Signal Transduction; STAT3 Transcription Factor; Tosyl Compounds