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

The hormonal sensitivity of prostate cancer has been exploited clinically since Huggins and Hodges established the suppressive effects of castration on prostate cancer. Despite over sixty years of research into alternate modalities, androgen deprivation therapy (ADT) has become the mainstay treatment for locally advanced and metastatic prostate cancer. Suppression of testosterone production, the primary goal of hormonal therapy, can be achieved by a multitude of treatments. The ideal timing, duration and composition of ADT remains undefined. At the present time, first-line therapy consists of orchiectomy, luteinizing hormone-releasing hormone (LHRH) analogues or complete androgen blockade (CAB). However, new combinations and treatment settings show promise for improving outcomes and decreasing toxicity. This article provides an overview of the hormonal therapies currently used in advanced prostate cancer.
Androgen Antagonists ; Castration ; Gonadotropin-Releasing Hormone ; Orchiectomy ; Prostatic Neoplasms ; Testosterone

OBJECTIVE: To explore potential therapeutic targets other than androgen-deprivation treatment for prostate cancer by screening the proteins induced by androgen at palmitoylation modification level in LNCaP cells. METHODS: The LNCaP cells were treated with androgen (Methyltrienolone, R1881, 5 nmol/L) or dimethyl sulfoxide (DMSO) for 24 h, and then labeled with alkynyl palmitic acid Alk-C16 (100 μmol/L). After that, the cells were collected, lysed, the total protein was extracted, agarose beads labeled with azide (1 mmol/L) were added, and the click-chemistry reaction was carried out at room temperature for 1 h. The covalent bond formed by click-chemistry reaction of azide and alkynyl group was used to enrich the palmitoylated proteins on agarose beads. Label-free quantitation (LFQ) was used to compare the protein palmitoylation level of R1881 treated and untreated cells to screen the proteins induced by androgen at palmitoylation modification level. RESULTS: In this experiment, 907 potential palmitoylated proteins (mascot score>2, P<0.05) were identified, among which 430 proteins had LFQ values not zero at least twice. Among the 430 proteins, the palmitoylation levels of 92 candidates were increased by androgen treatment, and their LFQ values were significantly upregulated (>1.5-fold, P<0.05) in ≥2 samples of androgen-treated vs. untreated LNCaP cells. We also used the software of cytoscape to classify the 92 proteins, and found that the known functional proteins of them could be divided into three categories: metabolism related, protein folding related and translation initiation related. Among them, metabolism related proteins included lipid metabolism (6), glucose metabolism (7) and respiratory electron transport chain (8), and a small amount of amino acid metabolism (2) and other metabolism related proteins (2). Notably, the ratio of LFQ of cytochrome b-c1 complex subunit 2 (UQCRC2) was significantly (>3-fold, P<0.05) higher in androgen-treated cells compared with untreated cells, indicating that the palmitoylation level of UQCRC2 was enhanced by androgen most significantly than that of others. The second was long-chain acyl CoA dehydrogenase (ACADVL) related to lipid metabolism and glucose 6-phosphate dehydrogenase (PGD) related to glucose metabolism, but the LFQ ratio of them was less than 3-fold. CONCLUSION The research on palmitoylation mechanism of metabolism, especially the proteins related to respiratory electron transport chain, will provide a new guidance for the diagnosis and treatment of prostate cancer and the development of targeted drugs.
Androgen Antagonists ; Androgens ; Humans ; Lipoylation ; Male ; Prostatic Neoplasms

Prostate cancer is among the most common malignancies in Western countries, and its incidence is rapidly rising in Asia where it was traditionally considered an uncommon tumor. Our understanding of the disease and management strategies continue to evolve. The first revolution of its treatment was in the 1940s when hormonal therapy was used to treat patients. The discovery of prostate-specific antigen (PSA) and the subsequent adoption of widespread PSA screening have made it possible to diagnose the disease early, but it was not until recently that the field realized that we had been overdiagnosing and overtreating a large number of men with indolent diseases that will not impact their quality of life or life expectancy. Distinguishing indolent tumors from aggressive ones remains a challenge, although recent advances in multiparametric MRI have given clinicians more confidence in choosing men for active surveillance. However, more need to be done to fundamentally understand the molecular and cellular bases that determine the biologic behavior of each of the tumors.
Androgen Antagonists ; Disease Progression ; Humans ; Male ; Prostatic Neoplasms/therapy*

Even in the era of novel targeted agents, switching to a second-line nonsteroidal antiandrogen (NSAA) is still widely used in treating metastatic castration-resistant prostate cancer (mCRPC), especially in undeveloped countries. However, whether prior treatment with a second-line NSAA would impact the efficacy of abiraterone acetate (Abi) remains uncertain. In the current study, 87 mCRPC patients treated with Abi were analyzed. Among them, 21 were treated with a second-line NSAA (from bicalutamide to flutamide) before receiving abiraterone, while the remaining 66 received Abi directly. Therapeutic efficacy of Abi was compared between those with and without prior second-line NSAA using Kaplan-Meier curves, log-rank test, and Cox regression models. The therapeutic efficacy of Abi was similar between those with or without the prior switching treatment of flutamide, in terms of either prostate-specific antigen progression-free survival (PSA-PFS, 5.5 vs 5.6 months, P = 0.967), radiographic progression-free survival (rPFS, 12.8 vs 13.4 months, P = 0.508), overall survival (OS, not reached vs 30.6 months, P = 0.606), or PSA-response rate (71.4% [15/21] vs 60.6% [40/66], P = 0.370). This is the first time that the impact of prior switching of treatment to a second-line NSAA on the efficacy of Abi in mCRPC patients has been addressed. Our data support that, use of prior sequential bicalutamide and flutamide does not seem to preclude response to abiraterone, although larger cohort studies and, ideally, a randomized controlled trial are needed. These findings will facilitate doctors' decision-making in the treatment of mCRPC patients, especially for those with previous experience of switching NSAA second-line treatments in the clinic.
Abiraterone Acetate/therapeutic use* ; Aged ; Aged, 80 and over ; Androgen Antagonists/therapeutic use* ; Anilides/therapeutic use* ; Antineoplastic Agents, Hormonal/therapeutic use* ; Disease-Free Survival ; Female ; Flutamide/therapeutic use* ; Humans ; Kaplan-Meier Estimate ; Male ; Nitriles/therapeutic use* ; Nonsteroidal Anti-Androgens/therapeutic use* ; Prostate-Specific Antigen/analysis* ; Prostatic Neoplasms, Castration-Resistant/drug therapy* ; Retrospective Studies ; Survival Analysis ; Tosyl Compounds/therapeutic use* ; Treatment Outcome

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