1-7-bis(4-hydroxy-3-methoxyphenyl)-1-4-6-heptatrien-3-one and Prostatic-Neoplasms

The prostate is an androgen-sensitive organ that needs proper androgen/androgen receptor (AR) signals for normal development. The progression of prostate diseases, including benign prostate hyperplasia (BPH) and prostate cancer (PCa), also needs proper androgen/AR signals. Tissue recombination studies report that stromal, but not epithelial, AR plays more critical roles via the mesenchymal-epithelial interactions to influence the early process of prostate development. However, in BPH and PCa, much more attention has been focused on epithelial AR roles. However, accumulating evidence indicates that stromal AR is also irreplaceable and plays critical roles in prostate disease progression. Herein, we summarize the roles of stromal AR in the development of normal prostate, BPH, and PCa, with evidence from the recent results of in vitro cell line studies, tissue recombination experiments, and AR knockout animal models. Current evidence suggests that stromal AR may play positive roles to promote BPH and PCa progression, and targeting stromal AR selectively with AR degradation enhancer, ASC-J9, may allow development of better therapies with fewer adverse effects to battle BPH and PCa.

Topics: Animals; Curcumin; Humans; Male; Neoplasm Proteins; Prostate; Prostatic Hyperplasia; Prostatic Neoplasms; Receptors, Androgen; Signal Transduction

The androgen receptor (AR) is a ligand-activated transcription factor that is expressed in primary and metastatic prostate cancers. There are advances in endocrine therapy for prostate cancer that are based on improved understanding of AR function.. PubMed has been used to include most important publications on targeting the AR in prostate cancer. AR expression may be downregulated by agents used for chemoprevention of prostate cancer or, in models of advanced prostate cancer, by antisense oligonucleotides. New drugs that inhibit the steroidogenic enzyme CYP17A1 (abiraterone acetate) or diminish nuclear translocation of the AR (enzalutamide) have been shown to improve patients' survival in prostate cancer. However, it is clear that there is a development of resistance to these novel therapies. They may include increased expression of truncated, constitutively active AR or activation of the signaling pathway of signal transducers and activators of transcription.. Although introduction of novel drugs have improved patients' survival, there is a need to investigate the mechanisms of resistance further. The role of truncated AR and compensatory activation of signaling pathways as well as the development of scientifically justified combination therapies seems to be issues of a high priority.

Topics: Androgen Antagonists; Anilides; Antibodies, Neutralizing; Anticarcinogenic Agents; Antineoplastic Agents; Benzamides; Cell Line, Tumor; Curcumin; Flutamide; Histone Deacetylase Inhibitors; HSP90 Heat-Shock Proteins; Humans; Male; Molecular Targeted Therapy; Nitriles; Oligonucleotides, Antisense; Phenylthiohydantoin; Phosphatidylinositol 3-Kinases; Prostatic Neoplasms; Receptors, Androgen; Signal Transduction; Steroid 17-alpha-Hydroxylase; Tosyl Compounds

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

Early studies indicated that ASC-J9®, an androgen receptor (AR) degradation enhancer, could suppress the prostate cancer (PCa) progression. Here we found ASC-J9® could also suppress the PCa progression via an AR-independent mechanism, which might involve modulating the tumor suppressor ATF3 expression.. The lentiviral system was used to modify gene expression in C4-2, CWR22Rv1 and PC-3 cells. Western blot and Immunohistochemistry were used to detect protein expression. MTT and Transwell assays were used to test the proliferation and invasion ability.. ASC-J9® can suppress PCa cell proliferation and invasion in both PCa C4-2 and CWR22Rv1 cells via altering the ATF3 expression. Further mechanistic studies reveal that ASC-J9® can increase the ATF3 expression via decreasing Glutamate-cysteine ligase catalytic (GCLC) subunit expression, which can then lead to decrease the PTK2 expression. Human clinical studies further linked the ATF3 expression to the PCa progression. Preclinical studies using in vivo mouse model also proved ASC-J9® could suppress AR-independent PCa cell invasion, which could be reversed after suppressing ATF3.. ASC-J9® can function via altering ATF3/PTK2 signaling to suppress the PCa progression in an AR-independent manner.

Topics: Activating Transcription Factor 3; Animals; Cell Line, Tumor; Cell Proliferation; Curcumin; Focal Adhesion Kinase 1; Humans; Male; Mice; Mice, Nude; Neoplasm Invasiveness; Prostatic Neoplasms; Signal Transduction; Xenograft Model Antitumor Assays

Chemotherapy with docetaxel remains the effective therapy to suppress castration resistant prostate cancer (CRPC) in some patients. However, most chemotherapy with docetaxel eventually fails with the development of docetaxel resistance after 18-weeks of treatment. Here we found docetaxel treatment might have an adverse effect of increasing the androgen receptor (AR) protein level in the CRPC cells, and combining docetaxel with anti-AR therapy using AR-shRNA or the AR degradation enhancer ASC-J9® may increase docetaxel sensitivity to better suppress the CRPC cell growth. Mechanism dissection found docetaxel might have the adverse effect of increasing the AR protein stability via suppressing the AR ubiquitination due to the increased AR phosphorylation. The consequence of such increased AR protein may then lead to increase p21 expression via transcriptional regulation. Preclinical studies with in vitro cells lines also demonstrated that targeting AR with ASC-J9® led to suppressing the AR-increased p21 expression to improve the docetaxel sensitivity in the CRPC cells that already developed docetaxel resistance. Together, these results suggest that a combined therapy of docetaxel and ASC-J9® is a novel therapy to better suppress CRPC in patients that already developed docetaxel resistance.

Topics: Antineoplastic Agents; Apoptosis; Cell Proliferation; Curcumin; Cyclin-Dependent Kinase Inhibitor p21; Docetaxel; Drug Resistance, Neoplasm; Drug Synergism; Gene Expression Regulation, Neoplastic; Humans; Male; Prostatic Neoplasms; Proteolysis; Receptors, Androgen; Tumor Cells, Cultured

While androgen deprivation therapy (ADT) and radiotherapy (RT) are currently used together to treat locally advanced prostate cancer (PCa), RT might have the adverse effect of increasing the PCa androgen receptor (AR) protein expression, which might then increase the resistance to continued RT.. We used multiple assays for RT sensitivity, protein and RNA expression of AR and related DDR genes, ROS level, DNA damage/repair level, cell cycle and apoptosis. All statistical comparisons were analyzed with t-test or one-way ANOVA.. We demonstrated that RT induced AR expression in C4-2 and CWR22Rv-1 cells. We found that combining RT and ASC-J9. Targeting ionizing radiation (IR)-increased AR with the AR degradation enhancer, ASC-J9

Topics: Animals; Cell Line, Tumor; Cell Movement; Curcumin; Disease Models, Animal; Disease Progression; Drug Evaluation, Preclinical; Gene Expression Regulation, Neoplastic; Humans; Male; Mice; Prostatic Neoplasms; Proteolysis; Radiation; Radiation Tolerance; Radiation-Sensitizing Agents; Radiotherapy; Receptors, Androgen; Signal Transduction; Xenograft Model Antitumor Assays

The androgen-deprivation therapy (ADT) to either reduce the androgen biosynthesis (for example, Abiraterone) or to prevent binding of androgen to the androgen receptor (AR), for example using Casodex or Enzalutamide, which may result in .decrease of the prostate cancer (PCa) cell growth, yet may also increase the PCa cell invasion. In contrast, the recently identified AR degradation enhancer ASC-J9

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Cell Movement; Cell Proliferation; Curcumin; Drug Resistance, Neoplasm; Epithelial-Mesenchymal Transition; Humans; Male; Mice; Neoplasm Invasiveness; Phosphorylation; Prostatic Neoplasms; Receptors, Androgen; Signal Transduction; STAT3 Transcription Factor; Sumoylation; Xenograft Model Antitumor Assays

Early studies suggested that prostate cancer (PCa) stem/progenitor (S/P) cells might play key roles to promote the tumor initiation and metastasis. Yet their linkage to the failure of androgen deprivation therapy (ADT), however, remains unclear. Here we demonstrated that the ADT with anti-androgens Casodex (also known as Bicalutamide) and Enzalutamide (also known as MDV3100), but not the newly identified AR degradation enhancer, ASC-J9(®), increased PCa S/P population, which might then lead to enhance the PCa cell invasion. Targeting AR with ASC-J9(®), and not targeting androgens with Casodex or Enzalutamide, led to suppress PCa S/P cell invasion. Mechanism dissection revealed ASC-J9(®) could suppress S/P cell invasion via altering the EZH2/STAT3 and/or AKT/EZH2/STAT3 signals. Together, these results suggest that targeting PCa S/P cells with ASC-J9(®) or inhibitors to interrupt the EZH2/STAT3 and/or Akt/EZH2/STAT3 signals may become a new therapy to overcome the unwanted side effects of Casodex or Enzalutamide to further suppress the PCa metastasis.

Topics: Androgen Antagonists; Anilides; Animals; Antineoplastic Agents, Hormonal; Benzamides; Cell Line, Tumor; Cell Movement; Curcumin; Enhancer of Zeste Homolog 2 Protein; Humans; Male; Mice, Nude; Neoplasm Invasiveness; Neoplastic Stem Cells; Nitriles; Phenylthiohydantoin; Prostatic Neoplasms; Proto-Oncogene Proteins c-akt; Side-Population Cells; Signal Transduction; STAT3 Transcription Factor; Tosyl Compounds; Xenograft Model Antitumor Assays

Infiltrating macrophages are a key component of inflammation during tumorigenesis, but the direct evidence of such linkage remains unclear. We report here that persistent coculturing of immortalized prostate epithelial cells with macrophages, without adding any carcinogens, induces prostate tumorigenesis and that induction involves the alteration of signaling of macrophage androgen receptor (AR)-inflammatory chemokine CCL4-STAT3 activation as well as epithelial-to-mesenchymal transition and downregulation of p53/PTEN tumor suppressors. In vivo studies further showed that PTEN(+/-) mice lacking macrophage AR developed far fewer prostatic intraepithelial neoplasia (PIN) lesions, supporting an in vivo role for macrophage AR during prostate tumorigenesis. CCL4-neutralizing antibody effectively blocked macrophage-induced prostate tumorigenic signaling and targeting AR via an AR-degradation enhancer, ASC-J9, reduced CCL4 expression, and xenografted tumor growth in vivo. Importantly, CCL4 upregulation was associated with increased Snail expression and downregulation of p53/PTEN in high-grade PIN and prostate cancer. Together, our results identify the AR-CCL4-STAT3 axis as key regulators during prostate tumor initiation and highlight the important roles of infiltrating macrophages and inflammatory cytokines for the prostate tumorigenesis.

Topics: Animals; Antibodies, Monoclonal; Cell Transformation, Neoplastic; Cells, Cultured; Chemokine CCL4; Curcumin; Cytokines; Enzyme-Linked Immunosorbent Assay; Epithelial-Mesenchymal Transition; Humans; Immunoenzyme Techniques; Macrophages; Male; Mice; Mice, Knockout; Prostate; Prostatic Intraepithelial Neoplasia; Prostatic Neoplasms; PTEN Phosphohydrolase; Receptors, Androgen; Signal Transduction; STAT3 Transcription Factor

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

The androgen deprivation therapy (ADT) to systematically suppress/reduce androgens binding to the androgen receptor (AR) has been the standard therapy for prostate cancer (PCa); yet, most of ADT eventually fails leading to the recurrence of castration resistant PCa. Here, we found that the PCa patients who received ADT had increased PCa stem/progenitor cell population. The addition of the anti-androgen, Casodex, or AR-siRNA in various PCa cells led to increased stem/progenitor cells, whereas, in contrast, the addition of functional AR led to decreased stem/progenitor cell population but increased non-stem/progenitor cell population, suggesting that AR functions differentially in PCa stem/progenitor vs. non-stem/progenitor cells. Therefore, the current ADT might result in an undesired expansion of PCa stem/progenitor cell population, which explains why this therapy fails. Using various human PCa cell lines and three different mouse models, we concluded that targeting PCa non-stem/progenitor cells with AR degradation enhancer ASC-J9 and targeting PCa stem/progenitor cells with 5-azathioprine and γ-tocotrienol resulted in a significant suppression of the tumors at the castration resistant stage. This suggests that a combinational therapy that simultaneously targets both stem/progenitor and non-stem/progenitor cells will lead to better therapeutic efficacy and may become a new therapy to battle the PCa before and after castration resistant stages.

Topics: Animals; Azacitidine; Curcumin; Decitabine; Disease Models, Animal; Gene Expression Regulation, Neoplastic; Humans; Male; Mice; Neoplastic Stem Cells; Orchiectomy; Prostatic Neoplasms; Receptors, Androgen; Signal Transduction; Xenograft Model Antitumor Assays

Using androgen receptor (AR) knockout mice to determine AR functions in selective prostate cancer (PCa) cells, we determined that AR might play differential roles in various cell types, either to promote or suppress PCa development/progression. These observations partially explain the failure of current androgen deprivation therapy (ADT) to reduce/prevent androgen binding to AR in every cell. Herein, we identified the AR degradation enhancer ASC-J9, which selectively degrades AR protein via interruption of the AR-AR selective coregulator interaction. Such selective interruption could, therefore, suppress AR-mediated PCa growth in the androgen-sensitive stage before ADT and in the castration-resistant stage after ADT. Mechanistic dissection suggested that ASC-J9 could activate the proteasome-dependent pathway to promote AR degradation through the enhanced association of AR-Mdm2 complex. The consequences of ASC-J9-promoted AR degradation included reduced androgen binding to AR, AR N-C terminal interaction, and AR nuclear translocation. Such inhibitory regulation could then result in suppression of AR transactivation and AR-mediated cell growth in eight different mouse models, including intact or castrated nude mice xenografted with androgen-sensitive LNCaP cells or androgen-insensitive C81 cells and castrated nude mice xenografted with castration-resistant C4-2 and CWR22Rv1 cells, and TRAMP and Pten(+/-) mice. These results demonstrate that ASC-J9 could serve as an AR degradation enhancer that effectively suppresses PCa development/progression in the androgen-sensitive and castration-resistant stages.

Topics: Animals; Antineoplastic Agents; Castration; Cell Line, Tumor; Chemoprevention; Curcumin; Disease Models, Animal; Epithelial Cells; Humans; Intracellular Signaling Peptides and Proteins; LIM Domain Proteins; Male; Mice; Mice, Nude; Nuclear Receptor Coactivators; Prostate; Prostatic Neoplasms; Proteolysis; PTEN Phosphohydrolase; Receptors, Androgen; Transcription, Genetic; Xenograft Model Antitumor Assays

Early studies suggested androgen receptor (AR) splice variants might contribute to the progression of prostate cancer (PCa) into castration resistance. However, the therapeutic strategy to target these AR splice variants still remains unresolved. Through tissue survey of tumors from the same patients before and after castration resistance, we found that the expression of AR3, a major AR splice variant that lacks the AR ligand-binding domain, was substantially increased after castration resistance development. The currently used antiandrogen, Casodex, showed little growth suppression in CWR22Rv1 cells. Importantly, we found that AR degradation enhancer ASC-J9 could degrade both full-length (fAR) and AR3 in CWR22Rv1 cells as well as in C4-2 and C81 cells with addition of AR3. The consequences of such degradation of both fAR and AR3 might then result in the inhibition of AR transcriptional activity and cell growth in vitro. More importantly, suppression of AR3 specifically by short-hairpin AR3 or degradation of AR3 by ASC-J9 resulted in suppression of AR transcriptional activity and cell growth in CWR22Rv1-fARKD (fAR knockdown) cells in which DHT failed to induce, suggesting the importance of targeting AR3. Finally, we demonstrated the in vivo therapeutic effects of ASC-J9 by showing the inhibition of PCa growth using the xenografted model of CWR22Rv1 cells orthotopically implanted into castrated nude mice with undetectable serum testosterone. These results suggested that targeting both fAR- and AR3-mediated PCa growth by ASC-J9 may represent the novel therapeutic approach to suppress castration-resistant PCa. Successful clinical trials targeting both fAR and AR3 may help us to battle castration-resistant PCa in the future.

Topics: Androgen Antagonists; Anilides; Animals; Antineoplastic Agents; Blotting, Western; Castration; Cell Line, Tumor; Curcumin; Drug Resistance, Neoplasm; Humans; Immunohistochemistry; Male; Mice; Mice, Nude; Nitriles; Prostatic Neoplasms; Protein Isoforms; Real-Time Polymerase Chain Reaction; Receptors, Androgen; Tosyl Compounds