Androgens control a broad range of physiological functions. The androgen receptor (AR), a steroid receptor that mediates the diverse biological actions of androgens, is a ligand inducible transcription factor. Abnormalities in the androgen signaling system result in many disturbances ranging from changes in gender determination and sexual development to psychiatric and emotional disorders. Androgen replacement therapy can improve many clinical conditions including hypogonadism and osteoporosis, but is limited by the lack of efficacious and safe therapeutic agents with easy delivery options. Recent progress in the area of gene regulation by steroid receptors and by selective receptor modulators provides an opportunity to examine if selective androgen receptor modulators (SARMs) could address some of the problems associated with current androgen therapy. Since the composition of the transcriptional initiation complex recruited by liganded AR determines the specificity of gene regulation, synthetic ligands aimed at initiating transcription of tissue and promoter specific genes offers hope for developing better androgen therapy. Establishment of assays that predict synthetic ligand activity is critical for SARM development. Advancement in high throughput compound screening and gene fingerprinting technologies, such as microarrays and proteomics, will facilitate and accelerate identification of effective SARMs.
Androgen Antagonists ; pharmacology ; Androgen Receptor Antagonists ; Androgens ; chemistry ; metabolism ; Chlormadinone Acetate ; analogs & derivatives ; pharmacology ; Humans ; Male ; Receptors, Androgen ; physiology ; Receptors, Cytoplasmic and Nuclear ; physiology ; Testosterone Congeners ; pharmacology

Therapy resistance is a significant challenge for prostate cancer treatment in clinic. Although targeted therapies such as androgen deprivation and androgen receptor (AR) inhibition are effective initially, tumor cells eventually evade these strategies through multiple mechanisms. Lineage reprogramming in response to hormone therapy represents a key mechanism that is increasingly observed. The studies in this area have revealed specific combinations of alterations present in adenocarcinomas that provide cells with the ability to transdifferentiate and perpetuate AR-independent tumor growth after androgen-based therapies. Interestingly, several master regulators have been identified that drive plasticity, some of which also play key roles during development and differentiation of the cell lineages in the normal prostate. Thus, further study of each AR-independent tumor type and understanding underlying mechanisms are warranted to develop combinational therapies that combat lineage plasticity in prostate cancer.
Androgen Antagonists/therapeutic use* ; Androgen Receptor Antagonists/therapeutic use* ; Gene Expression Regulation, Neoplastic ; Humans ; Male ; Prostatic Neoplasms/genetics* ; Prostatic Neoplasms, Castration-Resistant/genetics* ; Receptors, Androgen/drug effects*

ARAMIS is an international Phase III trial demonstrating the beneficial role of darolutamide, a novel anti-androgen that has been found to prolong metastasis-free survival in men with nonmetastatic castration-resistant prostate cancer. Darolutamide is a novel nonsteroidal androgen receptor antagonist that has unique structurally distinct properties with low blood–brain barrier penetration that was shown to improve metastasis-free survival by 22 months compared to placebo (40.4 months vs 18.4 months), reducing the risk of metastasis or death by 59%. Darolutamide also showed improvement in secondary and exploratory endpoints including progression-free survival, prolonged time to PSA progression, PSA response and time to initiating additional antineoplastic therapy, time to pain progression, and time to cytotoxic chemotherapy, but overall survival is not yet reached in either the darolutamide or the placebo arm. Adverse events leading to trial discontinuation were similar at 8.9% and 8.7% in the darolutamide and placebo arms, respectively. Darolutamide was filed as a new drug application to the United States Food and Drug Administration (US FDA) for use in the setting of nonmetastatic castration-resistant prostate cancer.
Androgen Receptor Antagonists ; Androgens ; Humans ; Male ; Prostatic Neoplasms, Castration-Resistant ; Pyrazoles

BACKGROUNDThe failure of endocrine treatment for advanced prostate cancer might be related to aberrant activation of androgen receptor (AR). Prostate cancer cell line LNCaP contains AR that can be activated by androgen, estrogen and progesterone. This study was set to investigate the effects of antisense AR RNA on growth of LNCaP cultured in medium containing varied concentrations of R1881, 17beta-estradiol, and progesterone, respectively.

METHODSLNCaP cells transfected with antisense AR RNA retroviral vector pL-AR-SN were designated as LNCaPas-AR. LNCaP cells containing empty vector pLXSN served as LNCaPNeo. LNCaP and LNCaPNeo were taken as controls. In vitro cell growth assay, proliferative cells of LNCaP and tranfected LNCaPs were counted by typan staining when they cultured with synthetic androgen R1881, 17beta-estradiol, and progesterone, respectively.

RESULTSGrowth of LNCaPas-AR was inhibited significantly (P < 0.05) compared with that of LNCaP and LNCaPNeo at 1 nmol/L R1881, 10 nmol/L 17beta-estradiol, and 1 nmol/L progesterone, respectively. No difference was seen between LNCaP and LNCaPNeo (P > 0.05). Microscopic observation showed that LNCaP and LNCaPNeo cells grew well, but only few LNCaPas-AR cells were alive.

CONCLUSIONSOur observations indicate that antisense AR RNA retroviral vector pL-AR-SN could change androgen-independent characteristics of LNCaP cells, which might shed some novel insights into the treatment of androgen-independent prostate cancer.

Androgen Receptor Antagonists ; Cell Division ; drug effects ; Cell Line, Tumor ; Dose-Response Relationship, Drug ; Estradiol ; pharmacology ; Humans ; Male ; Metribolone ; antagonists & inhibitors ; pharmacology ; Progesterone ; antagonists & inhibitors ; pharmacology ; Prostatic Neoplasms ; pathology ; therapy ; RNA, Antisense ; therapeutic use ; Receptors, Androgen ; genetics

AIMTo study the effect of curcumin on the apoptosis of prostate cancer cell line LNCaP and regulation of expression of maspin gene.

METHODSMTT and DNA electrophoresis were used to examine the cell growth and apoptosis of prostate cancer cell line LNCaP after treated with different doses of curcumin. The expression of maspin gene at transcription level and translation level was also detected by RT-PCR and Western blotting. pGL3-maspin luciferase expression vector, containing 847 bp (- 764 -/+ 83) DNA of maspin gene 5' promoter region, was transient transfected into LNCaP cell. Through detecting the activity of luciferase, the effect of curcumin on the promoter of maspin was studied.

RESULTSCurcumin inhibited cell growth, induced the apoptosis and enhanced the expression of maspin gene in LNCaP cells.

CONCLUSIONCurcumin up-regulated expression of maspin gene in LNCaP cells through enhancing the transcription activity of promoter of maspin gene.

Androgen Receptor Antagonists ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Curcumin ; pharmacology ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Male ; Promoter Regions, Genetic ; Prostatic Neoplasms ; drug therapy ; genetics ; pathology ; RNA, Messenger ; analysis ; Receptors, Androgen ; genetics ; Serpins ; genetics

OBJECTIVETo investigate the effects of testosterone on extracellular signal-regulated kinase l/2 ( ERK1/2) phosphorylation in human umbilical vein endothelial cells (HUVEC).

METHODSActivations of ERK1/2 stimulated by physiological testosterone were detected by Western blotting in cultured HUVEC.

RESULTSA rapid phosphorylation expression of ERK1/2 was observed by treatment of the HUVECs with 3 x 10(-8) mol/L testosterone, especially at 30 minutes. This phosphorylation was greatly inhibited by incubation with androgen receptor antagonist flutamide for 3 hours previously.

CONCLUSIONTestosterone at physiological concentrations induces the mitogen-activated protein kinase (MAPK, ERK1/2 and MEK1/2) phosphorylation within a short time, and flutamide could impair the process.

Androgen Receptor Antagonists ; Blotting, Western ; Cells, Cultured ; Endothelial Cells ; cytology ; drug effects ; metabolism ; Enzyme Activation ; drug effects ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Humans ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Phosphorylation ; drug effects ; Receptors, Androgen ; metabolism ; Testosterone ; pharmacology ; Umbilical Veins ; cytology

BACKGROUNDThe failure of hormone treatment for advanced prostate cancer might be related to aberrant activation of the androgen receptor. We have shown that (125)I labeled triple-helix forming oligonucleotide (TFO) against the androgen receptor gene inhibits androgen receptor expression and cell proliferation of LNCaP prostate cancer cells in vitro. This study aimed at exploring the effects of the (125)I-TFO on prostate tumor growth in vivo using a nude mouse xenograft model.

METHODSTFO was labeled with (125)I by the iodogen method. Thirty-two nude mice bearing LNCaP xenograft tumors were randomized into 4 groups and were intratumorally injected with (125)I-TFO, unlabeled TFO, Na(125)I and normal saline. Tumor size was measured weekly. The tumor growth inhibition rate (RI) was calculated by measurement of tumor weight. The expression of the androgen receptor gene was performed by RT-PCR and immunohistochemical study. The prostate specific antigen (PSA) serum levels were measured by enzyme linked immunosorbent assay. The tumor cell apoptosis index (AI) was detected by TUNEL assay.

RESULTSTumor measurements showed that tumor development was significantly inhibited by either (125)I-TFO or TFO, with tumor RIs of 50.79% and 32.80% respectively. (125)I-TFO caused greater inhibition of androgen receptor expression and higher AIs in tumor tissue than TFO. Both the tumor weight and the PSA serum levels in (125)I-TFO treated mice ((0.93 +/- 0.15) g and (17.43 +/- 1.85) ng/ml, respectively) were significantly lower than those ((1.27 +/- 0.21) g and (28.25 +/- 3.41) ng/ml, respectively) in TFO treated mice (all P < 0.05). Na(125)I did not significantly affect tumor growth and androgen receptor expression in tumor tissue.

CONCLUSIONSThe (125)I-TFO can effectively inhibit androgen receptor expression and tumor growth of human prostate cancer xenografts in vivo. The inhibitory efficacy of (125)I-TFO is more potent than that of TFO, providing a reference for future studies of antigen radiotherapy.

Androgen Receptor Antagonists ; Animals ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Enzyme-Linked Immunosorbent Assay ; Humans ; Immunohistochemistry ; Iodine Radioisotopes ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Oligonucleotides ; chemistry ; pharmacology ; therapeutic use ; Prostate-Specific Antigen ; blood ; Prostatic Neoplasms ; drug therapy ; metabolism ; pathology ; Receptors, Androgen ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Tumor Burden ; drug effects ; Xenograft Model Antitumor Assays ; methods

Androgen receptor (AR) is a ligand-activated transcription factor that plays a pivotal role in the development and progression of many severe diseases such as prostate cancer, muscle atrophy, and osteoporosis. Binding of ligands to AR triggers the conformational changes in AR that may affect the recruitment of coactivators and downstream response of AR signaling pathway. Therefore, AR ligands have great potential to treat these diseases. In this study, we searched for novel AR ligands by performing a docking-based virtual screening (VS) on the basis of the crystal structure of the AR ligand binding domain (LBD) in complex with its agonist. A total of 58 structurally diverse compounds were selected and subjected to LBD affinity assay, with five of them (HBP1-3, HBP1-17, HBP1-38, HBP1-51, and HBP1-58) exhibiting strong binding to AR-LBD. The IC values of HBP1-51 and HBP1-58 are 3.96 µM and 4.92 µM, respectively, which are even lower than that of enzalutamide (Enz, IC = 13.87 µM), a marketed second-generation AR antagonist. Further bioactivity assays suggest that HBP1-51 is an AR agonist, whereas HBP1-58 is an AR antagonist. In addition, molecular dynamics (MD) simulations and principal components analysis (PCA) were carried out to reveal the binding principle of the newly-identified AR ligands toward AR. Our modeling results indicate that the conformational changes of helix 12 induced by the bindings of antagonist and agonist are visibly different. In summary, the current study provides a highly efficient way to discover novel AR ligands, which could serve as the starting point for development of new therapeutics for AR-related diseases.
Androgen Receptor Antagonists ; pharmacology ; Androgens ; metabolism ; pharmacology ; Biological Assay ; Cell Line, Tumor ; Drug Discovery ; methods ; Humans ; Ligands ; Male ; Molecular Docking Simulation ; Molecular Dynamics Simulation ; Phenylthiohydantoin ; analogs & derivatives ; pharmacology ; Principal Component Analysis ; Prostatic Neoplasms ; drug therapy ; Protein Binding ; physiology ; Protein Conformation ; drug effects ; Receptors, Androgen ; metabolism

PURPOSE: Few data are available concerning the clinical outcome of abiraterone acetate treatment in patients with metastatic castration-resistant prostate cancer (mCRPC) in terms of the duration of androgen deprivation therapy (ADT) before diagnosis of CRPC. We investigated the clinical efficacy of abiraterone acetate according to the duration of ADT. MATERIALS AND METHODS: We reviewed the medical records of 20 patients with mCRPC who received abiraterone acetate after failure of docetaxel chemotherapy from May 2012 to March 2014 at Seoul National University Bundang Hospital. Clinical factors including prostate-specific antigen (PSA) nadir level, time to PSA nadir, PSA doubling time, PSA response, and modes of progression (PSA, radiologic, clinical) were analyzed. Disease progression was classified according to the Prostate Cancer Working Group 2 criteria. RESULTS: The mean age and PSA value of the entire cohort were 76.0+/-7.2 years and 158.8+/-237.9 ng/mL, respectively. The median follow-up duration was 13.4+/-6.7 months. There were no statistically significant differences in clinical characteristics between patients who received abiraterone acetate with ADT duration<35 months and those who received abiraterone acetate with ADT duration> or =35 months. There were also no significant differences in terms of PSA progression-free survival, radiologic progression-free survival, and clinical progression-free survival between patients with ADT duration<35 months and those with ADT duration > or =35 months. CONCLUSIONS: Although this was a retrospective study with a small sample size, we did not observe any statistically significant differences in the clinical response to abiraterone acetate between mCRPC patients with long ADT duration and those with short ADT duration in terms of disease progression-free survival.
Abiraterone Acetate/administration & dosage ; Aged ; Aged, 80 and over ; Androgen Receptor Antagonists/administration & dosage ; Antineoplastic Agents/administration & dosage ; Antineoplastic Combined Chemotherapy Protocols/*therapeutic use ; Disease Progression ; Drug Administration Schedule ; Humans ; Kallikreins/blood ; Male ; Neoplasm Metastasis ; Prostate-Specific Antigen/blood ; Prostatic Neoplasms, Castration-Resistant/*drug therapy ; Retrospective Studies ; Taxoids/administration & dosage ; Treatment Outcome

AIMTo explore the effect of androgen receptor (AR) on the expression of the cell cycle-related genes, such as CDKN1A and BTG1, in prostate cancer cell line LNCaP.

METHODSAfter AR antagonist flutamide treatment and confirmation of its effect by phase contrast microscope and flow cytometry, the differential expression of the cell cycle-related genes was analyzed by a cDNA microarray. The flutamide treated cells were set as the experimental group and the LNCaP cells as the control. We labeled cDNA probes of the experimental group and control group with Cy5 and Cy3 dyes, respectively, through reverse transcription. Then we hybridized the cDNA probes with cDNA microarrays, which contained 8 126 unique human cDNA sequences and the chip was scanned to get the fluorescent values of Cy5 and Cy3 on each spot. After primary analysis, reverse transcription polymerase chain reaction (RT-PCR) tests were carried out to confirm the results of the chips.

RESULTSAfter AR antagonist flutamide treatment, three hundred and twenty-six genes (3.93%) expressed differentially, 97 down-regulated and 219 up-regulated. Among them, eight up-regulated genes might be cell cycle-related, namely CDC10, NRAS, BTG1, Wee1, CLK3, DKFZP564A122, CDKN1A and BTG2. The CDKN1A and BTG1 gene mRNA expression was confirmed to be higher in the experimental group by RT-PCR, while p53 mRNA expression had no significant changes.

CONCLUSIONFlutamide treatment might up-regulate CDKN1A and BTG1 expression in prostate cancer cells. The protein expressions of CDKN1A and BTG1 play an important role in inhibiting the proliferation of cancer cells. CDKN1A has a great impact on the cell cycle of prostate cancer cells and may play a role in the cancer cells in a p53-independent pathway. The prostate cancer cells might affect the cell cycle-related genes by activating AR and thus break the cell cycle control.

Androgen Receptor Antagonists ; Antineoplastic Agents, Hormonal ; pharmacology ; Cell Cycle ; drug effects ; genetics ; Cell Line, Tumor ; Cyclin-Dependent Kinase Inhibitor p21 ; genetics ; Flutamide ; pharmacology ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Male ; Neoplasm Proteins ; genetics ; Oligonucleotide Array Sequence Analysis ; Prostate-Specific Antigen ; genetics ; Prostatic Neoplasms ; drug therapy ; pathology ; RNA, Messenger ; analysis ; Reverse Transcriptase Polymerase Chain Reaction