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Significance: Immunotherapy options for immune cold tumors, like prostate cancer, are limited. We show that AR downregulates MHCI expression/antigen presentation and that AR inhibition improves T-cell responses and tumor control. This suggests that treatments combining AR inhibitors and checkpoint blockade may improve tumor immune surveillance and antitumor immunity in patients., (©2024 The Authors; Published by the American Association for Cancer Research.)

The ligand-binding pocket of the androgen receptor (AR) is the targeting site of all clinically used AR antagonists. However, various drug-resistant mutations emerged in the pocket. We previously reported a new targeting site at the dimer interface of AR (dimer interface pocket) and identified a novel antagonist M17-B15 that failed in oral administration. In this study, the head part of M17-B15 was substituted with divergent structures. Potent antagonist Z10 with benzo[ b ]oxepine was first identified. Subsequent structural optimization on the 2-oxopropyl moiety of Z10 generated the more powerful Y5 (IC 50 = 0.04 μM). Out of the ordinary, Y5 demonstrated dual mechanisms of action, antagonized AR by disrupting AR dimerization, and induced AR degradation via the ubiquitin-proteasome pathway. Furthermore, Y5 exhibited excellent activity against variant drug-resistant AR mutants comparable to recently approved darolutamide. Furthermore, Y5 effectively suppressed the tumor growth of the LNCaP xenograft via oral administration, providing a potential novel therapeutic for drug-resistant prostate cancer.

Genetic alterations play a pivotal role in various human diseases, particularly cancer. The androgen receptor (AR) is a crucial transcription factor driving prostate cancer progression across all stages. Current AR-targeting therapies utilize competitive AR antagonists or pathway suppressors. However, therapy resistance often emerges due to AR mutations and AR splice variants, such as AR-v7. To overcome this, we developed ATC-324, an AR degrader using the innovative protein degradation technology platform AUTOphagy-TArgeting Chimera (AUTOTAC). ATC-324 was designed to comprise enzalutamide, an AR inhibitor, as a target-binding ligand and YT 6-2, a ligand of the autophagy receptor p62/SQSTM1, as an autophagy-targeting ligand. ATC-324 induces the formation of the AR/p62 complex, leading to autophagy-lysosomal degradation of AR. Importantly, ATC-324 effectively degrades AR mutants frequently detected in prostate cancer and codegrades AR-v7 as a heterodimer with full-length AR. ATC-324 reduces nuclear AR levels and downregulates the target gene expression of AR and AR-v7, leading to cytotoxicity in AR-positive prostate cancer cells. We also provide evidence of the therapeutic potential of ATC-324 in vivo as well as ex vivo bone organ culture. Moreover, ATC-324 remains potent in enzalutamide-resistant prostate cancer cells. These results demonstrate the potential of the AUTOTAC platform to target previously considered undruggable proteins and overcome certain drug resistance mechanisms. Significance: The characterization of an AUTOTAC-based degrader capable of inducing autophagic degradation of wild-type and mutated androgen receptors demonstrates the potential of this approach for targeting castration-resistant prostate cancer and overcoming drug resistance., (©2024 The Authors; Published by the American Association for Cancer Research.)

The clinical development of PROTACs targeting the androgen receptor (AR) for degradation has made significant progress. However, effective treatments for metastatic prostate cancers containing the androgen receptor splice variant 7 (AR-V7), a constitutively active mutant without the ligand-binding domain (LBD), are still lacking. Here, we reported the identification of a highly potent, noncovalent PROTAC targeting the N-terminal domain (NTD) of AR, NP18, which is developed from the covalent AR-NTD antagonist EPI-002, and effectively degrades both AR-FL and AR-V7 in 22Rv1 cells (DC 50 : 18 and 26 nM respectively). Mechanistically, NP18 interacts with the N-terminal domain (NTD) of both full-length AR (AR-FL) and splice variant 7 (AR-V7), leading to their selective and proteasomal degradation. Importantly, NP18 exhibited remarkably superior antitumor activity in both 22Rv1 xenograft and patient-derived xenograft (PDX) models than EPI-002. Taken together, these findings highlight NP18 as a promising candidate to counteract AR splice variant-driven resistance., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

The lack of targeted therapy for triple-negative breast cancer (TNBC) is among the mainsprings of its poor prognosis. This study aimed to elucidate the role of the androgen receptor (AR) and its splice variant 7 (ARv7) in TNBC patients. Further, the molecular impact of their blockers, Enzalutamide and EPI-001, on the TNBC cell line MDA-MB-231 was investigated. Thereby, immunohistochemical expression of AR/ARv7 was assessed for TNBC Egyptian patients. Moreover, bioinformatics analysis of AR/ARv7 RNA status was carried out on TNBC patients from The Cancer Genome Atlas Breast Carcinoma project (TCGA-BRCA). Data from both groups was correlated with patients' clinicopathological features. Besides, scratch wound healing assay and ELISA were employed to assess the effect of AR/ARv7 blockers on several metastasis markers in MDA-MB-231 cell line. In the Egyptian-TNBC patients, AR expression was associated with worse 7-year DFS (40.6 ± 18.6 %). In addition, ARv7 showed cytoplasmic and nuclear patterns, and both cytoplasmic and nuclear ARv7 + patients demonstrated a worse 7-year DFS (22.7 ± 17.7 % and 20 ± 17.9 %) and overall survival (63.6 ± 14.5 % and 40 ± 21.8 %). Importantly, 80 % of the nuclear ARv7 + patients developed distant metastasis. The data of the TCGA-TNBC patients showed a tendency for poor outcomes in the high ARv7-expressing patients. Molecularly, in MDA-MB-231, both inhibitors modulated metastasis and epithelial to mesenchymal transition (EMT) markers ROCK1, ROCK2, c-Myc, E-cadherin and N-cadherin, with EPI-001 downregulating NF-ĸB level as well. We concluded that ARv7 indicated poor prognosis in the studied cohorts and that blocking of AR/ARv7 abated metastasis and key regulators of EMT in MDA-MB-231, at least in part by targeting ROCK/NF-ĸB/c-Myc axis., Competing Interests: Declaration of interest The authors declare no conflict of interest exists., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

We report herein the development of a series of novel AR antagonists characterized by a spirocyclic scaffold, employing scaffold hopping and structure-based drug design strategies. Most of the spirocyclic derivatives exhibited enhanced AR antagonistic activity and superior antiproliferative activity against LNCaP cells compared to enzalutamide. Among them, compound 21 demonstrated moderate antiproliferative activity against enzalutamide resistant prostate cancer cell lines and exhibited favorable in vitro metabolic stability. These findings offer valuable insights for the rational design of AR antagonists for the treatment of advanced prostate cancer., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier Ltd. All rights reserved.)

Despite treatment, prostate cancer commonly progresses into castration-resistant prostate cancer (CRPC), which remains largely incurable, requiring the development of new interventions. Darolutamide is an orally administered second-generation androgen receptor inhibitor indicated for patients with non-metastatic CRPC or metastatic hormone-sensitive prostate cancer. Here, we evaluated the effect of androgen receptor (AR) inhibition by darolutamide in combination with DNA double-strand-break-inducing targeted radium-223 alpha therapy in vitro and in an intratibial LNCaP xenograft model mimicking prostate cancer metastasized to bone. The results highlight the synergistic antitumor efficacy of darolutamide in combination with radium-223 both in vitro and in vivo. This effect was most likely driven by the downregulation of genes involved in DDR signaling, which was demonstrated in vitro by a gene set enrichment analysis. The combination treatment also reduced pathological tumor-induced effects in bone by decreasing the number of osteoblasts and osteoclasts and reducing abnormal bone formation in tumor-bearing bone. Additionally, it was shown that darolutamide does not affect the uptake of radium-223 into bone tissue. These results support the investigation of darolutamide in combination with radium-223 for the treatment of patients with CRPC metastasized to bone.

Background: Advanced prostate cancer (PCa) often initially responds to androgen receptor signaling inhibitors (ARSI) but frequently develops resistance, driven by tumor heterogeneity and therapeutic pressure. Addressing the clinical challenge of identifying non-responsive patients and discovering new therapeutic targets is urgently needed., Methods: We utilized single-sample gene set enrichment analysis (ssGSEA) to elucidate the influence of the GG-NER pathway on ARSI response in PCa. We then constructed and validated a prognostic model based on this pathway using LASSO regression, Kaplan-Meier analysis, Cox regression, and ROC analysis. Additionally, we mapped tumor mutations to delineate the mutational landscapes across different risk groups and explored functional pathways through GO, KEGG, and GSEA analyses. The impact of the GG-NER pathway on enzalutamide sensitivity and DNA repair in PCa was further validated through CCK-8 assays, colony formation assays, in vivo experiments, and immunofluorescence., Results: ssGSEA indicated a trend of GG-NER pathway upregulation in patients with poor ARSI response. The GG-NER characteristic gene score (NECGS) identified a high-risk group with diminished ARSI response, serving as an independent prognostic indicator with strong predictive power. This high-risk group exhibited elevated TP53 mutation frequencies and significant enrichment in key pathways such as ribosome and mitochondrial functions, as well as MYC and E2F signaling. Experimental validation confirmed that targeting the GG-NER pathway or its key gene, ACTL6A, significantly reduces enzalutamide resistance in resistant cell lines and increases γH2AX expression., Conclusion: NECGS effectively predicts ARSI response in PCa, and our comprehensive analysis underscores the critical role of the GG-NER pathway in enzalutamide resistance, positioning ACTL6A as a potential therapeutic target for PCa., Competing Interests: Declarations. Ethics approval and consent to participate: All the transcriptome data of PCa patients was acquired from open-sourced platforms including TCGA, cBioPortal, GDC Portal and UCSC websites, and the voluntarily informed consent for patients was not available. The current study was approved by the Ethics Committee of Zhujiang Hospital, Southern Medical University. Competing interests: The authors declare no competing interests. Competing of interest: The authors declare that they do not have any conflicts of interest., (© 2024. The Author(s).)

Inhibiting the activity of the androgen receptor (AR) is the cornerstone treatment for advanced prostate cancer. AR-targeted therapies are highly effective in slowing disease progression but are not curative. Failure of these therapies results in a disease state termed castration-resistant prostate cancer, which is associated with significant patient morbidity and mortality. In most cases, resistance to AR-targeted therapies arises due to alterations that reactivate the AR signalling axis. Interestingly, it has long been recognised that potent activation of AR with supraphysiological levels of androgens can suppress prostate cancer growth in both preclinical models and patients. This intriguing paradox, where both inhibition and activation of AR have anti-cancer effects, is now being harnessed clinically in the form of bipolar androgen therapy (BAT). This review describes mechanisms underlying the tumour-suppressive functions of AR in the context of potent androgenic stimulation and discusses how our maturing understanding of these processes is influencing the clinical deployment of BAT.

Introduction: Prostate cancer (PCa) is the second most common cancer diagnosis among men worldwide, with poor prognosis in its advanced stage. Treatment strategies have evolved, including the use of androgen receptor pathway inhibitors (ARPIs) and poly (ADP-ribose) polymerase inhibitors (PARPis)., Areas Covered: This review evaluates the clinical efficacy, safety, and future potential of combining talazoparib, a potent PARPi, with enzalutamide, a strong androgen receptor (AR) antagonist. The combination of these two drugs was evaluated by the TALAPRO-2 trial, demonstrating significant improvement in radiographic progression-free survival (rPFS) in metastatic castration-resistant prostate cancer (mCRPC) patients, particularly those with Homologous Recombination Repair (HRR) gene mutations such as BRCA1/2., Expert Opinion: Emerging biomarkers like TMPRSS2-ERG and RB1 gene mutations have been recently reported as potential predictors of clinical outcome in the TALAPRO-2 all-comers population. Genomic markers for homologous recombination deficiency (HRD) are other potential drivers of response to PARPi/ARPI combination. Further investigation is needed to refine treatment strategies, including targeting non-HRR mutations, and to expand the role of this combination therapy in earlier stages of prostate cancer.

The transformation of clinical androgen receptor (AR) antagonists into agonists driven by AR mutations poses a significant challenge in treating prostate cancer (PCa). Novel anti-AR therapeutics combating mutation-induced resistance are required. Herein, by combining structure-based virtual screening and biological evaluation, a high-affinity agonist E10 was first discovered. Then guided by the representative conformation of State 1 at the free energy landscape, the structural optimization of E10 was performed, and pure AR antagonists EL15 (IC 50 = 0.94 μM) and EF2 (IC 50 = 0.30 μM) were successfully identified. Both can antagonize wild-type and variant drug-resistant ARs. Therein, EF2 demonstrated potent inhibition of the AR pathway and effectively suppressed tumor growth in a C4-2B xenograft mouse model following oral administration. Further molecular dynamics simulation and mutagenesis studies revealed atomic insights into the mode of action of EF2 which may serve as a novel lead compound for developing therapeutics against AR-driven PCa.

Sustained androgen receptor (AR) signaling during relapse is a central driver of metastatic castration-resistant prostate cancer (mCRPC). Current AR antagonists, such as enzalutamide, fail to provide long-term benefit for the mCRPC patients who have dramatic increases in AR expression. Here, we report AR antagonists with efficacy in AR-overexpressing models. These molecules bind to the ligand-binding domain of the AR, promote AR localization to the nucleus, yet potently and selectively down-regulate AR-target genes. The molecules BG-15a and the pharmacokinetically optimized BG-15n elicit a decrease in cell and tumor growth in vitro and in vivo in models of mCRPC. BG-15a/n treatment causes the collapse of chromatin loops between enhancers and promoters at key genes in the AR-driven epigenome. AR binding in the promoter, as well as 3D chromatin clustering, is needed for genes to respond. BG-15a/n represent promising agents for treating patients with relapsed AR-driven mCRPC tumors., Competing Interests: Competing interests statement:E.C. received research funding under institutional SRA from Janssen Research and Development, Bayer Pharmaceuticals, KronosBio, Forma Pharmaceutics Foghorn, Gilead, Sanofi, AbbVie, MacrogGenics, Astra Zeneca, GSK, and K36. B.E.G., A.K.O., S.T., W.D.F., and J.S. are co-inventors on a patent covering this technology (WO2021150603A1). P.S.N. receives personal fees from Janssen, Bristol Myers Squibb, Pfizer, and Merck and grants from Janssen. The other authors declare no competing interests.

Androgen receptor (AR) is a crucial driver of prostate cancer (PCa), but acquired resistance to AR antagonists significantly undermines their clinical efficacy. We previously discovered coumarin derivative 1 , which is capable of disrupting AR ligand-binding domain dimers, offering the potential for overcoming resistance. However, its poor oral bioavailability limited further development. In this study, comprehensive structure optimizations led to compound 4a (IC 50 = 0.051 μM), which exhibited comparable AR antagonistic activity to enzalutamide (IC 50 = 0.060 μM) and demonstrated excellent selectivity over other nuclear receptors in vitro. Especially, 4a showed superior efficacy against AR F876L/T877A and AR W741C mutants compared to darolutamide and enzalutamide. Moreover, 4a exhibited favorable pharmacokinetic profiles ( F = 66.24%) in vivo and significant tumor growth inhibition in an LNCaP xenograft mouse model upon oral administration. These results highlight the potential of 4a as a promising oral AR antagonist for overcoming drug resistance in PCa.

Androgen deprivation therapy has been the primary treatment strategy for advanced prostate cancer (PCa). But most patients develop castration resistance over time. For FDA-approved second-generation androgen receptor (AR) antagonists, including enzalutamide (ENZ) and abiraterone (AA), patients who initially respond to them eventually develop resistance. The key mechanism for resistance to ENZ/AA involves AR splice variants (AR-Vs) and specifically AR-V7. Current AR antagonists cannot target AR-V7 due to its lack of the C-terminal ligand-binding domain (LBD) but keeping the AR N-terminal domain (NTD) which still can activate androgen-responsive genes. Therefore, targeting the AR NTD and AR-V7 is critically important to overcome ENZ resistance. Unfortunately, AR NTD has been considered an "undruggable" target due to the difficulty in defining its three-dimensional (3D) structure. In this context, siRNA is highly suitable to address this undruggable target. However, siRNA cannot freely diffuse into cells, and a carrier is needed. In this regard, nucleic acid-based aptamers are highly suitable for cell type-specific delivery of siRNA in vivo. In this study, we have developed a serum-stable bivalent prostate-specific membrane antigen (PSMA) aptamer-AR-V7 siRNA chimera (PAP). The results show that PAP can knock down both AR-full length and AR-V7 in PSMA-expressing castration-resistant cells. It can resensitize ENZ in cell lines and PCa xenografts. ENZ combined with PAP can significantly inhibit 22Rv1 xenograft growth in mice without experiencing castration. Owing to the low toxicity, PAP has potential to offer a new antiandrogen treatment for current ENZ-resistant PCa.

The combination of androgen signaling inhibitors and PARP inhibitors has shown promising results in clinical trials for the treatment of castration-resistant prostate cancer (CRPC). Multi-target inhibitors can inhibit tumors through different pathways, addressing the limitations of traditional single target inhibitors. We designed and synthesized dual inhibitors targeting AR/AR-Vs and PARP1 using a pharmacophore hybridization strategy. The most potent compound, II-3, inhibits AR/AR-Vs signaling and induces DNA damage by inhibiting PARP1. The IC 50 values of II-3 in the castration-resistant prostate cancer cell lines 22RV1 and C4-2 are 4.38 ± 0.56 µM, and 3.44 ± 0.63 µM, respectively. II-3 not only suppresses the proliferation and migration of 22RV1 and C4-2 cells, but also promotes their apoptosis. Intraperitoneal injection of II-3 effectively inhibits tumor growth in 22RV1 xenograft nude mice without evident drug-induced toxicity. Overall, a series of novel dual inhibitors targeting AR/AR-Vs and PARP1 were designed and synthesized, and meanwhile the in vivo and in vitro effects were comprehensively explored, which provided a potential new therapeutic strategy for CRPC., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Introduction: Prostate cancer continues to be a major cause of morbidity and mortality for men worldwide. Enzalutamide, a second-generation non-steroidal antiandrogen that blocks androgen receptor (AR) transcriptional activity, is a treatment for biochemically recurrent, metastatic, castration-sensitive, and castration-resistant tumors. Unfortunately, most patients ultimately develop resistance to enzalutamide, making long-term treatment with this agent challenging., Areas Covered: We performed a literature search of PubMed without date restrictions to investigate the literature surrounding enzalutamide and discuss the current uses of enzalutamide, proposed mechanisms driving resistance, and summarize current efforts to mitigate this resistance., Expert Opinion: Enzalutamide is an effective prostate cancer therapy that is currently used in biochemically recurrent and metastatic disease and for both castration-sensitive and castration-resistant tumors. Unfortunately, resistance to enzalutamide occurs in each of these scenarios. In the clinical setting, enzalutamide-resistant tumors are either AR-driven or AR-indifferent. AR-dependent resistance mechanisms include genomic or epigenomic events that result in enhanced AR signaling. Tumors that do not require AR signaling instead may depend on alternative oncogenic pathways. There are numerous strategies to mitigate enzalutamide resistance, including concurrent use of PARP inhibitors or immune therapies. Additional work is required to uncover novel approaches to treat patients in the enzalutamide-resistant setting.

Prostate cancer represents a major global health challenge, necessitating efficacious therapeutic strategies. Androgen receptor pathway inhibitors (ARPIs) have become central to prostate cancer treatment, demonstrating significant effectiveness in both metastatic and non-metastatic contexts. Abiraterone acetate, by inhibiting androgen synthesis, deprives cancer cells androgens necessary for growth, while second-generation androgen receptor (AR) antagonists disrupt AR signaling by blocking AR binding, thereby impeding tumor progression. Given the predominance of prostate cancer in the elderly, who often present with multiple comorbidities requiring complex pharmacological regimens, the potential for drug-drug interactions with ARPIs is a critical concern. These interactions, particularly through pathways like CYP2D6 inhibition by abiraterone and CYP3A4 induction by enzalutamide and apalutamide, necessitate a thorough understanding to optimize therapeutic outcomes and minimize adverse effects. This review aims to delineate the efficacy of ARPIs in prostate cancer management and elucidate their interaction with common medications, highlighting the importance of vigilant drug management to optimize patient care., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Androgen receptor (AR) is an important therapeutic target for prostate cancer (PCa) treatment, but prolonged use of AR antagonists has led to variant drug-resistant mutations. Since all marketed AR antagonists target the ligand binding pocket (LBP) of AR, to mitigate cross-resistance, a new drug pocket named Dimer Interface Pocket was discovered and a novel AR antagonist M17-B15 was identified. M17-B15 showed strong in vitro efficacy against PCa but had poor pharmacokinetic properties in vivo . In this study, through rational design and structure-activity relationship exploration, a series of thiadiazoleamide derivatives represented by N29 (IC 50 = 0.018 μM) were identified with dominant AR antagonistic activity and remarkable anti-PCa activity in vitro . Furthermore, N29 effectively inhibited a series of typical drug-resistant AR mutants. The improved oral bioavailability of N29 facilitated its efficacy via oral administration, significantly inhibiting LNCaP xenograft tumor in vivo , presenting a promising therapeutic application for PCa.

Androgen receptor (AR) and its ligand androgens are important for development and physiology of various tissues. AR and its ligands also play critical role in the development of various diseases, making it a valuable therapeutic target. AR ligands, both agonists and antagonists, are being widely used to treat pathological conditions, including prostate cancer and hypogonadism. Despite AR being studied widely over the last five decades, the last decade has seen striking advances in the knowledge on AR and discoveries that have the potential to translate to the clinic. This review provides an overview of the advances in AR biology, AR molecular mechanisms of action, and next generation molecules that are currently in development. Several of the areas described in the review are just unraveling and the next decade will bring more clarity on these developments that will put AR at the forefront of both basic biology and drug development., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Proton pump inhibitors (PPIs) are widely used due to their affordability and minimal severe side effects. However, their influence on the efficacy of cancer treatments, particularly androgen receptor signaling inhibitors (ARSIs), remains unclear. This study investigates the impact of PPI usage on the treatment outcomes in patients with metastatic castration-resistant prostate cancer (mCRPC)., Methods: A total of 117 mCRPC patients were retrospectively analyzed and divided into two groups based on the concomitant use of PPI at the initiation of ARSI treatment: PPI+ (n = 38) and PPI- (n = 79). Patient characteristics, including age at ARSI treatment administered, prostate-specific antigen (PSA) value at ARSI treatment administered, International Society of Urological Pathology grade group at prostate biopsy, metastatic site at ARSI treatment administered, prior docetaxel (DTX) treatment, and type of ARSI (abiraterone acetate or enzalutamide) were recorded. Progression-free survival (PFS), overall survival (OS), and PSA response rates were compared between the two groups. Patients were further stratified by clinical background to compare PFS and OS between the two groups., Results: The PPI- group exhibited significantly extended PFS and a trend toward improved OS. For PSA response (reduction of 50% or more from baseline), the rates were 62.3% and 45.9% in the PPI- group and the PPI+ group, respectively. For deep PSA response (reductions of 90% or more from baseline), the rates were 36.4% and 24.3% in the PPI- group and the PPI+ group, respectively. The effects were consistent across subgroups divided by prior DTX treatment and type of ARSI administered., Conclusions: The administration of PPIs appears to diminish the therapeutic efficacy of ARSIs in mCRPC patients. Further prospective studies are needed to confirm these findings and explore the biological mechanisms involved., (© 2024 Wiley Periodicals LLC.)

Prostate cancer (PCa) is the leading cause of cancer‑related death among men worldwide. PCa often develops resistance to standard androgen deprivation therapy and androgen receptor (AR) pathway inhibitors, such as enzalutamide (ENZ). Therefore, there is an urgent need to develop novel therapeutic strategies for this disease. The efficacy of ADA‑308 was evaluated through in vitro assessments of AR activity and cell proliferation, alongside in vivo studies. ADA‑308 has emerged as a promising candidate, demonstrating potent inhibition of AR‑sensitive adenocarcinoma as well as ENZ‑resistant PCa cell lines. The results of the study revealed that ADA‑308 effectively blocked AR activity, including its nuclear localization, and inhibited cell proliferation in vitro . Furthermore, ADA‑308 demonstrated notable efficacy in vivo , with a robust antitumor response in ENZ‑resistant models. These findings establish the role of ADA‑308 as a potent AR inhibitor that overcomes resistance to AR‑targeted therapies and highlights its potential as a novel therapeutic approach in advanced PCa management.

The androgen receptor (AR) is a modular transcription factor which functions as a master regulator of gene expression. AR protein is composed of three functional domains; the ligand-binding domain (LBD); DNA-binding domain (DBD); and the intrinsically disordered N-terminal transactivation domain (TAD). AR is transactivated upon binding to the male sex hormone testosterone and other androgens. While the AR may tolerate loss of its LBD, the TAD contains activation function-1 (AF-1) that is essential for all AR transcriptional activity. AR is frequently over-expressed in most prostate cancer. Currently, androgen deprivation therapy (ADT) in the form of surgical or chemical castration remains the standard of care for patients with high risk localized disease, advanced and metastatic disease, and those patients that experience biochemical relapse following definitive primary treatment. Patients with recurrent disease that receive ADT will ultimately progress to lethal metastatic castration-resistant prostate cancer. In addition to ADT not providing a cure, it is associated with numerous adverse effects including cardiovascular disease, osteoporosis and sexual dysfunction. Recently there has been a renewed interest in investigating the possibility of using antiandrogens which competitively bind the AR-LBD without ADT for patients with hormone sensitive, non-metastatic prostate cancer. Here we describe a class of compounds termed AR transactivation domain inhibitors (ARTADI) and their mechanism of action. These compounds bind to the AR-TAD to inhibit AR transcriptional activity in the absence and presence of androgens. Thus these inhibitors may have utility in preventing prostate cancer growth in the non-castrate setting., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Introduction: The androgen receptor (AR) is a critical driver of prostate cancer progression, and the advent of androgen receptor pathway inhibitors (ARPIs) has transformed the treatment landscape of metastatic prostate cancer. However, resistance to ARPIs eventually develops via mutations in AR, AR overexpression, and alternative AR signaling which have required novel approaches to target effectively., Areas Covered: The mechanism of action and early clinical results of proteolysis targeting chimera (PROTAC) agents targeting AR are reviewed. Preclinical and early clinical data for other emerging AR-targeting therapeutics, including dual-action androgen receptor inhibitors (DAARIs) and anitens that target the N-terminal domain of AR, were also identified through literature search for agents which may circumvent resistance through AR splice variants and AR ligand-binding domain mutations. The literature search utilized PubMed to identify articles that were relevant to this review from 2000 to 2024., Expert Opinion: PROTACs, DAARIs, and anitens represent novel and promising AR-targeting therapeutics that may become an important part of prostate cancer treatment in the future. Elucidating mechanisms of resistance, including ability of these agents to target full length AR, may yield further insights into maximal therapeutic efficacy aimed at silencing AR signaling.

The androgen receptor (AR) is an attractive target for treating prostate cancer, considering its role in the development and progression of localized and metastatic prostate cancer. The high global mortality burden of prostate cancer, despite medical treatments such as androgen deprivation or AR antagonist therapy, highlights the need to explore alternative strategies. One strategy involves the use of heterobifunctional degraders, also known as proteolysis-targeting chimeras, which are novel small-molecule therapeutics that inhibit amplified or mutated targets. Here, the study reports a novel cereblon-based AR degrader, UBX-390, and demonstrates its superior activity over established AR degraders, such as ARV-110 or ARCC-4, in prostate cancer cells under short- and long-term treatment conditions. UBX-390 suppresses chromatin binding and gene expression of AR and demonstrates substantial efficacy in the degradation of AR mutants in patients with treatment-resistant prostate cancer. UBX-390 is presented as an optimized AR degrader with remarkable potential for treating castration-resistant prostate cancer., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Introduction: Androgenetic alopecia (AGA) is the most prevalent cause of male hair loss, often requiring medical and/or surgical intervention. The US FDA has approved topical minoxidil and oral finasteride for male AGA treatment. However, some AGA patients fail to respond satisfactorily to these FDA-approved treatments and/or may experience side effects, based on their individual profiles. To mitigate the shortcomings of these treatments, researchers are now exploring alternative treatments such as newer 5-α reductase inhibitors (5-ARIs) and androgen receptor antagonists (ARAs)., Areas Covered: This article reviews the safety and effectiveness of well-known 5-α reductase inhibitors (5-ARIs) like finasteride and dutasteride, as well as the newer 5-ARIs, emerging androgen receptor antagonists (ARAs), and natural products such as saw palmetto and pumpkin seed oil in the treatment of male AGA., Expert Opinion: Although several newer 5-ARIs, ARAs, and natural products have exhibited promise in clinical trials, additional research is essential to confirm their safety and efficacy in treating male AGA. Until additional evidence is available for these agents, the preferred treatment choices for male AGA are the FDA-approved treatments, topical minoxidil, and oral finasteride.

Despite recent advances in the treatment of metastatic prostate cancer, progression to a castration-resistant state remains inevitable for most and prognosis is limited. Genetic testing for homologous recombination repair pathway alterations is recommended for all patients with advanced prostate cancer given that a mutation is present in up to 25% of cases. Poly(ADP-ribose) polymerase (PARPis) are now approved for use in patients with metastatic castration-resistant prostate cancer who have progressed on an androgen receptor pathway inhibitor (ARPI) and harbour a germline or somatic homologous recombination repair mutation. Preclinical data support a synergistic effect with an ARPI and PARPi, and various ARPI-PARPi combinations have therefore been explored in phase III clinical trials. Despite heterogeneous findings, a clear hierarchy of benefit is evident, with patients harbouring a BRCA mutation deriving the greatest magnitude of benefit, followed by any homologous recombination repair mutation. The benefit in homologous recombination repair-proficient cohort is less clear, and questions remain about whether ARPI-PARPi combination therapy should be offered to patients without a homologous recombination repair mutation. With ARPIs now considered standard-of-care for metastatic hormone-sensitive prostate cancer, ARPI-PARPi combination therapy is currently being explored earlier in the treatment paradigm. The purpose of this review is to discuss the rationale behind ARPI-PARPi combination therapy, summarise the results of key clinical trials, and discuss clinical considerations and future perspectives., (© 2024. The Author(s).)

Androgen receptor (AR), a steroid receptor, plays a pivotal role in the pathogenesis of prostate cancer (PCa). AR controls the transcription of genes that help cells avoid apoptosis and proliferate, thereby contributing to the development of PCa. Understanding AR molecular mechanisms has led to the development of newer drugs that inhibit androgen production enzymes or block ARs. The FDA has approved a small number of AR-inhibiting drugs for use in PCa thus far, as the identification of novel AR inhibitors is difficult, expensive, time-consuming, and labor-intensive. To accelerate the process, artificial intelligence (AI) algorithms were employed to predict AR inhibitors using a dataset of 2242 compounds. Four machine learning (ML) and deep learning (DL) algorithms were used to train different prediction models based on molecular descriptors (1D, 2D, and molecular fingerprints). The DL-based prediction model outperformed the other trained models with accuracies of 92.18% and 93.05% on the training and test datasets, respectively. Our findings highlight the potential of DL, particularly the DNN model, as an effective approach for predicting AR inhibitors, which could significantly streamline the process of identifying novel AR inhibitors in PCa drug discovery. Further validation of these models using experimental assays and prospective testing of newly designed compounds would be valuable to confirm their predictive power and applicability in practical drug discovery settings.Communicated by Ramaswamy H. Sarma.

Prostate cancer (PCa) is the second most prevalent malignancy among men worldwide. The aberrant activation of androgen receptor (AR) signaling has been recognized as a crucial oncogenic driver for PCa and AR antagonists are widely used in PCa therapy. To develop novel AR antagonist, a machine-learning MIEC-SVM model was established for the virtual screening and 51 candidates were selected and submitted for bioactivity evaluation. To our surprise, a new-scaffold AR antagonist C2 with comparable bioactivity with Enz was identified at the initial round of screening. C2 showed pronounced inhibition on the transcriptional function (IC 50  = 0.63 μM) and nuclear translocation of AR and significant antiproliferative and antimetastatic activity on PCa cell line of LNCaP. In addition, C2 exhibited a stronger ability to block the cell cycle of LNCaP than Enz at lower dose and superior AR specificity. Our study highlights the success of MIEC-SVM in discovering AR antagonists, and compound C2 presents a promising new scaffold for the development of AR-targeted therapeutics., (© 2024. The Author(s), under exclusive licence to Shanghai Institute of Materia Medica, Chinese Academy of Sciences and Chinese Pharmacological Society.)

Androgen receptor (AR)-targeting therapy induces oxidative stress in prostate cancer. However, the mechanism of oxidative stress induction by AR-targeting therapy remains unclear. This study investigated the mechanism of oxidative stress induction by AR-targeting therapy, with the aim to develop novel therapeutics targeting oxidative stress induced by AR-targeting therapy. Intracellular reactive oxygen species (ROS) was examined by fluorescence microscopy and flow cytometry analysis. The effects of silencing gene expression and small molecule inhibitors on gene expression and cytotoxic effects were examined by quantitative real-time PCR and cell proliferation assay. ROS induced by androgen depletion co-localized with peroxisomes in prostate cancer cells. Among peroxisome-related genes, PPARA was commonly induced by AR inhibition and involved in ROS production via PKC signaling. Inhibition of PPARα by specific siRNA and a small molecule inhibitor suppressed cell proliferation and increased cellular sensitivity to the antiandrogen enzalutamide in prostate cancer cells. This study revealed a novel pathway by which AR inhibition induced intracellular ROS mainly in peroxisomes through PPARα activation in prostate cancer. This pathway is a promising target for the development of novel therapeutics for prostate cancer in combination with AR-targeting therapy such as antiandrogen enzalutamide., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Masaki Shiota received honoraria from Janssen Pharmaceutical, AstraZeneca, Astellas Pharma, Sanofi and Bayer Yakuhin and research funding support from Astellas Pharma. Masatoshi Eto received honoraria from Ono Pharmaceutical, Takeda Pharmaceutical, Novartis Pharma, Pfizer, Bristol-Myers Squibb, Janssen Pharmaceutical, MSD, Merck Biopharma, AstraZeneca and Eisai, and research funding support from Bayer Yakuhin, Astellas Pharma, Ono Pharmaceutical and Takeda Pharmaceutical., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

BACKGROUNDAndrogen receptor signaling inhibitors (ARSIs) have improved outcomes for patients with metastatic castration-resistant prostate cancer (mCRPC), but their clinical benefit is limited by treatment resistance.METHODSTo investigate the mechanisms of ARSI resistance, we analyzed the whole-genome (n = 45) and transcriptome (n = 31) sequencing data generated from paired metastatic biopsies obtained before initiation of first-line ARSI therapy for mCRPC and after radiographic disease progression. We investigated the effects of genetic and pharmacologic modulation of SSTR1 in 22Rv1 cells, a representative mCRPC cell line.RESULTSWe confirmed the predominant role of tumor genetic alterations converging on augmenting androgen receptor (AR) signaling and the increased transcriptional heterogeneity and lineage plasticity during the emergence of ARSI resistance. We further identified amplifications involving a putative enhancer downstream of the AR and transcriptional downregulation of SSTR1, encoding somatostatin receptor 1, in ARSI-resistant tumors. We found that patients with SSTR1-low mCRPC tumors derived less benefit from subsequent ARSI therapy in a retrospective cohort. We showed that SSTR1 was antiproliferative in 22Rv1 cells and that the FDA-approved drug pasireotide suppressed 22Rv1 cell proliferation.CONCLUSIONOur findings expand the knowledge of ARSI resistance and point out actionable next steps, exemplified by potentially targeting SSTR1, to improve patient outcomes.FUNDINGNational Cancer Institute (NCI), NIH; Prostate Cancer Foundation; Conquer Cancer, American Society of Clinical Oncology Foundation; UCSF Benioff Initiative for Prostate Cancer Research; Netherlands Cancer Institute.

As alternatives of perfluorooctanoic acid (PFOA), hexafluoropropylene oxide dimeric acid (HFPO-DA) and trimeric acid (HFPO-TA) have been detected increasingly in environmental media and even humans. They have been shown to exhibit reproductive toxicity to model species, but their effects on human remain unclear due to the knowledge gap in their mode of action. Herein, (anti-)androgenic effects of the two HFPOs and PFOA were investigated and underlying toxicological mechanism was explored by combining zebrafish test, cell assay and molecular docking simulation. Exposure of juvenile zebrafish to the chemicals during sex differentiation promoted feminization, with HFPO-TA acting at an environmental concentration of 1 μg/L. The chemicals inhibited proliferation of human prostate cells and transcriptional activity of human and zebrafish androgen receptors (AR), with HFPO-TA displaying the strongest potency. Molecular docking revealed that the chemicals bind to AR in a conformation similar to a known AR antagonist. Combined in vivo, in vitro and in silico results demonstrated that the chemicals disrupted sex differentiation likely by antagonizing AR-mediated pathways, and provided more evidence that HFPO-TA is not a safe alternative to PFOA., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Second-generation androgen receptor (AR) signaling inhibitors (ARSIs), such as abiraterone and enzalutamide, prolong the life of patients with castration-resistant prostate cancer (CRPC). However, patients receiving ARSIs ultimately develop resistance through various complex mechanisms, including AR mutations, constitutively active AR-splice variants (AR-Vs), and AR overexpression. Here, we characterized a novel AR pure antagonist, TAS3681, which inhibits AR transcriptional activity and downregulates AR-full length (AR-FL) and AR-Vs. TAS3681 reduced the protein levels of AR-FL and AR-Vs including AR-V7 in enzalutamide-resistant cells (SAS MDV No. 3-14), in vitro and in vivo, showing strong antitumor efficacy in an AR-V7-positive xenograft model. In AR-overexpressing VCaP (prostate cancer) cells, conversely to enzalutamide, TAS3681 effectively suppressed cell proliferation and downregulated AR expression. Importantly, TAS3681 blocked the transcriptional activity of various mutant ARs, including mutations F877L/T878A and H875Y/T878A, which confer resistance to enzalutamide, and V716M and H875Y mutations, which confer resistance to darolutamide. Our results demonstrate that TAS3681 suppresses the reactivation of AR signaling, which causes resistance to ARSIs, via a newly identified mechanism of action. Therefore, TAS3681 could be a new therapeutic option for CRPC treatment., (© 2024 Taiho Pharmaceutical Co., Ltd. Molecular Oncology published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)

Androgen receptor (AR) signaling plays a key role in the progression of prostate cancer. This study describes the discovery and optimization of a novel series of AR PROTAC degraders that recruit the Cereblon (CRBN) E3 ligase. Having identified a series of AR ligands based on 4-(4-phenyl-1-piperidyl)-2-(trifluoromethyl)benzonitrile, our PROTAC optimization strategy focused on linker connectivity and CRBN ligand SAR to deliver potent degradation of AR in LNCaP cells. This work culminated in compounds 11 and 16 which demonstrated good rodent oral bioavailability. Subsequent SAR around the AR binding region brought in an additional desirable feature, degradation of the important treatment resistance mutation L702H. Compound 22 (AZ'3137) possessed an attractive profile showing degradation of AR and L702H mutant AR with good oral bioavailability across species. The compound also inhibited AR signaling in vitro and tumor growth in vivo in a mouse prostate cancer xenograft model.

A practical and efficient synthesis of the C8-C23 fragment of antarlides A-H, incorporating six stereocenters and a conjugated diene, is reported. A strategic combination of synthetic methods, including CBS reduction, Evans' aldol reaction, Keck-Maruoka allylation, and enzymatic resolution, enabled the selective introduction of these stereocenters. Furthermore, the pivotal coupling of key fragments is successfully executed through a Julia-Kocienski olefination reaction, connecting the C8-C14 and C15-C23 subunits.

Background: Patients with nonmetastatic castration-resistant prostate cancer (nmCRPC) are usually asymptomatic and seek treatments that improve survival but have a low risk of adverse events. Darolutamide, a structurally distinct androgen receptor inhibitor (ARi), significantly reduced the risk of metastasis and death versus placebo in ARAMIS. We assessed the extended safety and tolerability of darolutamide and the time-course profile of treatment-emergent adverse events (TEAEs) related to ARis and androgen-suppressive treatment., Patients and Methods: Patients with nmCRPC were randomized 2:1 to darolutamide (n = 955) or placebo (n = 554). After trial unblinding, patients could receive open-label darolutamide. Tolerability and TEAEs were assessed every 16 weeks. Time interval-specific new and cumulative event rates were determined during the first 24 months of the double-blind period., Results: Darolutamide remained well tolerated during the double-blind and open-label periods, with 98.8% of patients receiving the full planned dose. The incidence of TEAEs of interest in the darolutamide group was low and ≤2% different from that in the placebo group, except for fatigue. When incidences were adjusted for exposure time, there were minimal differences between the darolutamide double-blind and double-blind plus open-label periods. The rate of initial onset and cumulative incidence of grade 3/4 TEAEs and serious TEAEs were similar for darolutamide and placebo groups over 24 months., Conclusion: Extended treatment with darolutamide was well tolerated and no new safety signals were observed. Most ARi-associated and androgen-suppressive treatment-related TEAEs occurred at low incidences with darolutamide, were similar to placebo, and showed minimal increase over time with continued treatment., Trial Number: ClinicalTrials.gov identifier NCT02200614., (© The Author(s) 2024. Published by Oxford University Press.)

As a nuclear transcription factor, the androgen receptor (AR) plays a crucial role not only in normal male sexual differentiation and growth of the prostate, but also in benign prostatic hyperplasia, prostatitis, and prostate cancer. Multiple population-based epidemiological studies demonstrated that prostate cancer risk was inversely associated with increased dietary intakes of green tea, soy products, tomato, and so forth. Therefore, this review aimed to summarize the structure and function of AR, and further illustrate the structural basis for antagonistic mechanisms of the currently clinically available antiandrogens. Due to the limitations of these antiandrogens, a series of natural AR inhibitors have been identified from edible plants such as fruits and vegetables, as well as folk medicines, health foods, and nutritional supplements. Hence, this review mainly focused on recent experimental, epidemiological, and clinical studies about natural AR inhibitors, particularly the association between dietary intake of natural antiandrogens and reduced risk of prostatic diseases. Since natural products offer multiple advantages over synthetic antiandrogens, this review may provide a comprehensive and updated overview of dietary-derived AR inhibitors, as well as their potential for the nutritional intervention against prostatic disorders., (© 2024 Wiley Periodicals LLC.)

In this work, a series of curcumin derivatives (1a-1h, 2a-2g, and 3a-3c) were synthesized for the suppression of castration-resistant prostate cancer cells. All synthesized compounds were characterized by 1 H NMR, 13 C NMR, HRMS, and melting point. The in vitro cytotoxicity study shows that compounds 1a, 1e, 1f, 1h, 2g, 3a, and 3c display similar or enhanced cytotoxicity against 22Rv1 and C4-2 cells as compared to ASC-J9, other synthesized compounds display reduced cytotoxicity against 22Rv1 and C4-2 cells as compared to ASC-J9. Molecular docking simulation was performed to study the binding affinity and probable binding modes of the synthesized compounds with androgen receptor. The results show that all synthesized compounds exhibit higher cdocker interaction energies as compared to ASC-J9. Compounds 1h, 2g, and 3c not only show strong cytotoxicity against 22Rv1 and C4-2 cells but also exhibit high binding affinity with androgen receptor. In androgen receptor suppression study, compounds 1f and 2g show similar androgen receptor suppression effect as compared to ASC-J9 on C4-2 cells, compound 3c displays significantly enhanced AR suppression effect as compared to ASC-J9, 1f and 2g. Compounds 1a, 1e, 1f, 1h, 2g, 3a and 3c prepared in this work have significant potential for castration-resistant prostate cancer therapy., (© 2024 John Wiley & Sons Ltd.)

Second-generation AR antagonists, such as enzalutamide, are the primary therapeutic agents for advanced prostate cancer. However, the development of both primary and secondary drug resistance leads to treatment failures and patient mortality. Bifunctional agents that simultaneously antagonize and degrade AR block the AR signaling pathway more completely and exhibit excellent antiproliferative activity against wild-type and drug-resistant prostate cancer cells. Here, we reported the discovery and optimization of a series of biphenyl derivatives as androgen receptor antagonists and degraders. These biphenyl derivatives exhibited potent antiproliferative activity against LNCaP and 22Rv1 cells. Our discoveries enrich the diversity of small molecule AR degraders and offer insights for the development of novel AR degraders for the treatment of enzalutamide-resistant prostate cancer., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

After the initial androgen deprivation therapy (ADT), part of the prostate cancer may continuously deteriorate into castration-resistant prostate cancer (CRPC). The majority of patients suffer from the localized illness at primary diagnosis that could rapidly assault other organs. This disease stage is referred as metastatic castration-resistant prostate cancer (mCRPC). Surgery and radiation are still the treatment of CRPC, but have some adverse effects such as urinary symptoms and sexual dysfunction. Hormonal castration therapy interfering androgen receptor (AR) signaling pathway is indispensable for most advanced prostate cancer patients, and the first- and second-generation of novel AR inhibitors could effectively cure hormone sensitive prostate cancer (HSPC). However, the resistance to these chemical agents is inevitable, so many of patients may experience relapses. The resistance to AR inhibitor mainly involves AR mutation, splice variant formation and amplification, which indicates the important role in CRPC. Proteolysis-targeting chimera (PROTAC), a potent technique to degrade targeted protein, has recently undergone extensive development as a biological tool and therapeutic drug. This technique has the potential to become the next generation of antitumor therapeutics as it could overcome the shortcomings of conventional small molecule inhibitors. In this review, we summarize the molecular mechanisms on PROTACs targeting AR signaling for CRPC, hoping to provide insights into drug development and clinical medication., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Metabolic reprogramming and mitochondrial dynamics are pivotal in prostate cancer (PCa) progression and treatment resistance, making them essential targets for therapeutic intervention. In this study, we investigated the effects of the androgen receptor antagonist apalutamide (ARN) and the mitochondrial electron transport chain complex I inhibitor IACS-010759 (IACS) on the mitochondrial network architecture and dynamics in PCa cells. Treatment with ARN and/or IACS induced significant changes in mitochondrial morphology, particularly elongation, in androgen-sensitive PCa cells. Additionally, ARN and IACS modulated the mitochondrial fission and fusion processes, indicating a convergence of metabolic and androgen-signaling pathways in shaping mitochondrial function. Notably, the combination treatment with ARN and IACS resulted in increased apoptotic cell death and mitochondrial oxidative stress selectively in the androgen-sensitive PCa cells. Our findings highlight the therapeutic potential of targeting mitochondrial metabolism in prostate cancer and emphasize the need for further mechanistic understanding to optimize treatment strategies and improve patient outcomes., Competing Interests: The authors declare no conflicts of interest.

Introduction: The therapeutic scenario of metastatic hormone-sensitive prostate cancer (mHSPC) has dramatically changed in recent years, with the approval of new-generation Androgen Receptor Signaling Inhibitors (ARSIs), in combination with the androgen deprivation therapy (ADT), which was the previous standard of care. Despite showing a similar clinical efficacy, ARSIs, all of which are administered orally, are different in terms of pharmacokinetic and drug-drug interactions (DDIs)., Areas Covered: This review covers the main pharmacokinetic characteristics of ARSIs that have been approved for the first-line therapy of mHSPC patients, underlying the differences among these molecules and focusing on the known or possible interactions with other drugs. Full-text articles and abstracts were searched in PubMed., Expert Opinion: Since prostate cancer occurs mainly in older age, comorbidities and the consequent polypharmacy increase the DDI risk in mHSPC patients who are candidates for ARSI. Waiting for new therapeutic options, in the absence of direct comparisons, pharmacokinetic knowledge is essential to guide clinicians in prescribing ARSI in this setting.

The androgen receptor AR antagonists, such as enzalutamide and apalutamide, are efficient therapeutics for the treatment of prostate cancer (PCa). Even though they are effective at first, resistance to both drugs occurs frequently. Resistance is mainly driven by aberrations of the AR signaling pathway including AR gene amplification and the expression of AR splice variants (e.g. AR-V7). This highlights the urgent need for alternative therapeutic strategies. Here, a total of 24 compounds were synthesized and biologically evaluated to disclose compound 20i, exhibiting potent AR antagonistic activities (IC 50  = 172.85 ± 21.33 nM), promising AR/AR-V7 protein degradation potency, and dual targeting site of probably AR (ligand-binding domain, LBD and N-terminal domain, NTD). It potently inhibits cell growth with IC 50 values of 4.87 ± 0.52 and 2.07 ± 0.34 μM in the LNCaP and 22RV1 cell lines, respectively, and exhibited effective tumor growth inhibition (TGI = 50.9 %) in the 22RV1 xenograft study. These data suggest that 20i has the potential for development as an AR/AR-V7 inhibitor with degradation ability to treat advanced prostate cancer., Competing Interests: Declaration of competing interest The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript., (Copyright © 2024. Published by Elsevier Masson SAS.)

Prostate Cancer (PCa) easily progress to metastatic Castration-Resistant Prostate Cancer (mCRPC) that remains a significant cause of cancer-related death. Androgen receptor (AR)-dependent transcription is a major driver of prostate tumor cell proliferation. Proteolysis-targeting chimaera (PROTAC) technology based on Hydrophobic Tagging (HyT) represents an intriguing strategy to regulate the function of therapeutically androgen receptor proteins. In the present study, we have designed, synthesized, and evaluated a series of PROTAC-HyT AR degraders using AR antagonists, RU59063, which were connected with adamantane-based hydrophobic moieties by different alkyl chains. Compound D-4-6 exhibited significant AR protein degradation activity, with a degradation rate of 57 % at 5 μM and nearly 90 % at 20 μM in 24 h, and inhibited the proliferation of LNCaP cells significantly with an IC 50 value of 4.77 ± 0.26 μM in a time-concentration-dependent manner. In conclusion, the present study lays the foundation for the development of a completely new class of therapeutic agents for the treatment of mCRPC, and further design and synthesis of AR-targeting degraders are currently in progress for better degradation rate., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

A new chemical scaffold with antagonistic activity towards the androgen receptor (AR) was identified. The parent compound, (3-Methoxy-N-[1-methyl-2-(4-phenyl-1-piperazinyl)-2-(2-thienyl)ethyl]benzamide) referred to as MEL-6, binds in the ligand binding pocket of AR and induces an antagonistic conformation of the ligand binding domain, even in presence of the antagonist-to-agonist switch mutations W741C, T877A and F876L-T877A. MEL-6 has antiproliferative effects on several AR positive prostate cancer cell lines. We further identified AR as the specific target of MEL-6 since it demonstrates little effect on other steroid receptors. In LNCaP cells it also inhibits the androgen-regulated transcriptome. These findings identify MEL-6 as a promising candidate for treatment of patients with prostate tumors that have become resistant to current clinically used AR antagonists. Analytical studies on the chemical composition of MEL-6 identified the presence of four isomers (two enantiomeric pairs), among which one isomer is responsible for the antiandrogenic activity. We therefore developed a synthetic route towards the selective preparation of the active enantiomeric pair. Various MEL-6-like analogues had improved metabolic stability while maintaining antiandrogenic activity. Metabolite identification of MEL-6 derivatives pinpointed N-dealkylation of the piperazine as the main mode for inactivation by liver enzymes. For further structural optimization, MEL-6 derivatives were purchased or synthesized having alterations on the N-phenyl group of the piperazine, the benzoyl group and additionally substituting the thiophen-2-yl ring of MEL-6 to a phenyl ring. This optimization process resulted in compound 12b with sustained AR inhibition and a 4-fold increased half-life due to the 1-(5-chloro-2-methylphenyl)-piperazine substitution, thienyl-to-phenyl substitution and chloro in para-position of the benzoyl group., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Androgen deprivation therapies (ADT) are the mainstay treatments for castration-resistant prostate cancer (CRPC). ADT suppresses the androgen receptor (AR) signaling by blocking androgen biosynthesis or inhibiting AR with antiandrogens that target AR's ligand-binding domain (LBD). However, the ADT's effect is short-lived, as the AR signaling inevitably arises again, which is frequently coupled with AR-V7 overexpression. AR-V7 is a truncated form of AR that lacks the LBD, thus being constitutively active in the absence of androgens and irresponsive to AR-LBD-targeting inhibitors. Though compelling evidence has tied AR-V7 to drug resistance in CRPC, pharmacological inhibition of AR-V7 is still an unmet need. Here, we discovered a small molecule, SC912, which binds to full-length AR as well as AR-V7 through AR N-terminal domain (AR-NTD). This pan-AR targeting relies on the amino acids 507-531 in the AR-NTD. SC912 also disrupted AR-V7 transcriptional activity, impaired AR-V7 nuclear localization and DNA binding. In the AR-V7 positive CRPC cells, SC912 suppressed proliferation, induced cell-cycle arrest, and apoptosis. In the AR-V7 expressing CRPC xenografts, SC912 attenuated tumor growth and antagonized intratumoral AR signaling. Together, these results suggested the therapeutic potential of SC912 for CRPC., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Androgen receptor (AR) antagonists are widely used for the treatment of prostate cancer (PCa), but their therapeutic efficacy is usually compromised by the rapid emergence of drug resistance. However, the lack of the detailed interaction between AR and its antagonists poses a major obstacle to the design of novel AR antagonists. Here, funnel metadynamics is employed to elucidate the inherent regulation mechanisms of three AR antagonists (hydroxyflutamide, enzalutamide, and darolutamide) on AR. For the first time it is observed that the binding of antagonists significantly disturbed the C-terminus of AR helix-11, thereby disrupting the specific internal hydrophobic contacts of AR-LBD and correspondingly the communication between AR ligand binding pocket (AR-LBP), activation function 2 (AF2), and binding function 3 (BF3). The subsequent bioassays verified the necessity of the hydrophobic contacts for AR function. Furthermore, it is found that darolutamide, a newly approved AR antagonist capable of fighting almost all reported drug resistant AR mutants, can induce antagonistic binding structure. Subsequently, docking-based virtual screening toward the dominant binding conformation of AR for darolutamide is conducted, and three novel AR antagonists with favorable binding affinity and strong capability to combat drug resistance are identified by in vitro bioassays. This work provides a novel rational strategy for the development of anti-resistant AR antagonists., (© 2024 The Authors. Advanced Science published by Wiley‐VCH GmbH.)

Background: Nonmetastatic castration-resistant prostate cancer (nmCRPC) patients are often older and use concurrent medications that increase the potential for drug-drug interactions (pDDIs). This study assessed pDDI prevalence in real-world nmCRPC patients treated with apalutamide, darolutamide, or enzalutamide., Research Design and Methods: Castrated prostate cancer patients without metastases prior to androgen receptor inhibitor initiation were identified retrospectively via Optum Clinformatics Data Mart claims data (8/2019-3/2021). The top 100 concomitant medications were assessed for pDDIs., Results: Among 1,515 patients (mean age: 77 ± 8 years; mean Charlson Comorbidity Index: 3 ± 3), 340 initiated apalutamide, 112 darolutamide, and 1,063 enzalutamide. Common concomitant medication classes were cardiovascular (80%) and central nervous system (52%). Two-thirds of the patients received ≥5 concomitant medications; 30 (30/100 medications) pDDIs were identified for apalutamide and enzalutamide each and 2 (2/100 medications) for darolutamide. Most pDDIs had risk ratings of C or D, but four for apalutamide were rated X. Approximately 58% of the patients on apalutamide, 5% on darolutamide, and 54% on enzalutamide had ≥1 identified pDDI., Conclusions: Results showed a higher frequency of pDDIs in patients receiving apalutamide and enzalutamide vs darolutamide. The impact of these could not be determined retrospectively. DDI risk should be carefully evaluated when discussing optimal therapy for patients with nmCRPC.

While pentacyclic triterpenoids have a rich history in chemistry and biology, the challenges associated with their asymmetric synthesis contribute to the current reality that medicinal exploration in the area is largely constrained to natural product derivatization. To address this deficiency, a function-oriented synthesis of pentacyclic triterpenoids was pursued. Overall, we report a divergent synthesis of 26-norgermanicol and 26-norlupeol and we have identified a new class of androgen receptor antagonist that is ∼6× more potent than lupeol.