Androgens play an important role in prostate cancer development and progression. Androgen action is mediated through the androgen receptor (AR), a ligand-dependent DNA-binding transcription factor. AR is arguably the most important target for prostate cancer treatment. Current USA Food and Drug Administration (FDA)-approved AR inhibitors target the ligand-binding domain (LBD) and have exhibited efficacy in prostate cancer patients, particularly when used in combination with androgen deprivation therapy. Unfortunately, patients treated with the currently approved AR-targeting agents develop resistance and relapse with castration-resistant prostate cancer (CRPC). The major mechanism leading to CRPC involves reactivation of AR signaling mainly through AR gene amplification, mutation, and/or splice variants. To effectively inhibit the reactivated AR signaling, new approaches to target AR are being actively explored. These new approaches include novel small molecule inhibitors targeting various domains of AR and agents that can degrade AR. The present review provides a summary of the existing FDA-approved AR antagonists and the current development of some of the AR targeting agents.
Humans ; Male ; Androgen Receptor Antagonists/therapeutic use* ; Receptors, Androgen/metabolism* ; Prostatic Neoplasms/drug therapy* ; Prostatic Neoplasms, Castration-Resistant/drug therapy* ; Signal Transduction/drug effects*

Mitogen-activated protein kinase-8-interacting protein 2 (MAPK8IP2) is a scaffold protein that modulates MAPK signal cascades. Although MAPK pathways were heavily implicated in prostate cancer progression, the regulation of MAPK8IP2 expression in prostate cancer is not yet reported. We assessed MAPK8IP2 gene expression in prostate cancer related to disease progression and patient survival outcomes. MAPK8IP2 expression was analyzed using multiple genome-wide gene expression datasets derived from The Cancer Genome Atlas (TCGA) RNA-sequence project and complementary DNA (cDNA) microarrays. Multivariable Cox regressions and log-rank tests were used to analyze the overall survival outcome and progression-free interval. MAPK8IP2 protein expression was evaluated using the immunohistochemistry approach. The quantitative PCR and Western blot methods analyzed androgen-stimulated MAPK8IP2 expression in LNCaP cells. In primary prostate cancer tissues, MAPK8IP2 mRNA expression levels were significantly higher than those in the case-matched benign prostatic tissues. Increased MAPK8IP2 expression was strongly correlated with late tumor stages, lymph node invasion, residual tumors after surgery, higher Gleason scores, and preoperational serum prostate-specific antigen (PSA) levels. MAPK8IP2 upregulation was significantly associated with worse overall survival outcomes and progression-free intervals. In castration-resistant prostate cancers, MAPK8IP2 expression strongly correlated with androgen receptor (AR) signaling activity. In cell culture-based experiments, MAPK8IP2 expression was stimulated by androgens in AR-positive prostate cancer cells. However, MAPK8IP2 expression was blocked by AR antagonists only in androgen-sensitive LNCaP but not castration-resistant C4-2B and 22RV1 cells. These results indicate that MAPK8IP2 is a robust prognostic factor and therapeutic biomarker for prostate cancer. The potential role of MAPK8IP2 in the castration-resistant progression is under further investigation.
Male ; Humans ; Androgens/therapeutic use* ; Receptors, Androgen/genetics* ; Prognosis ; Mitogen-Activated Protein Kinase 8/therapeutic use* ; Cell Line, Tumor ; Prostatic Neoplasms/pathology* ; Prostatic Neoplasms, Castration-Resistant/drug therapy* ; Gene Expression Regulation, Neoplastic

Management and treatment of terminal metastatic castration-resistant prostate cancer (mCRPC) remains heavily debated. We sought to investigate the efficacy of programmed cell death 1 (PD-1) inhibitor plus anlotinib as a potential solution for terminal mCRPC and further evaluate the association of genomic characteristics with efficacy outcomes. We conducted a retrospective real-world study of 25 mCRPC patients who received PD-1 inhibitor plus anlotinib after the progression to standard treatments. The clinical information was extracted from the electronic medical records and 22 patients had targeted circulating tumor DNA (ctDNA) next-generation sequencing. Statistical analysis showed that 6 (24.0%) patients experienced prostate-specific antigen (PSA) response and 11 (44.0%) patients experienced PSA reduction. The relationship between ctDNA findings and outcomes was also analyzed. DNA-damage repair (DDR) pathways and homologous recombination repair (HRR) pathway defects indicated a comparatively longer PSA-progression-free survival (PSA-PFS; 2.5 months vs 1.2 months, P = 0.027; 3.3 months vs 1.2 months, P = 0.017; respectively). This study introduces the PD-1 inhibitor plus anlotinib as a late-line therapeutic strategy for terminal mCRPC. PD-1 inhibitor plus anlotinib may be a new treatment choice for terminal mCRPC patients with DDR or HRR pathway defects and requires further investigation.
Male ; Humans ; Prostate-Specific Antigen ; Treatment Outcome ; Prostatic Neoplasms, Castration-Resistant/drug therapy* ; Immune Checkpoint Inhibitors/therapeutic use* ; Retrospective Studies

Reprogramming of metabolism is a hallmark of tumors, which has been explored for therapeutic purposes. Prostate cancer (PCa), particularly advanced and therapy-resistant PCa, displays unique metabolic properties. Targeting metabolic vulnerabilities in PCa may benefit patients who have exhausted currently available treatment options and improve clinical outcomes. Among the many nutrients, glutamine has been shown to play a central role in the metabolic reprogramming of advanced PCa. In addition to amino acid metabolism, glutamine is also widely involved in the synthesis of other macromolecules and biomasses. Targeting glutamine metabolic network by maximally inhibiting glutamine utilization in tumor cells may significantly add to treatment options for many patients. This review summarizes the metabolic landscape of PCa, with a particular focus on recent studies of how glutamine metabolism alterations affect therapeutic resistance and disease progression of PCa, and suggests novel therapeutic strategies.
Male ; Humans ; Glutamine/therapeutic use* ; Prostatic Neoplasms, Castration-Resistant/drug therapy*

The final analysis of the phase 3 Targeted Investigational Treatment Analysis of Novel Anti-androgen (TITAN) trial showed improvement in overall survival (OS) and other efficacy endpoints with apalutamide plus androgen deprivation therapy (ADT) versus ADT alone in patients with metastatic castration-sensitive prostate cancer (mCSPC). As ethnicity and regional differences may affect treatment outcomes in advanced prostate cancer, a post hoc final analysis was conducted to assess the efficacy and safety of apalutamide in the Asian subpopulation. Event-driven endpoints were OS, and time from randomization to initiation of castration resistance, prostate-specific antigen (PSA) progression, and second progression-free survival (PFS2) on first subsequent therapy or death. Efficacy endpoints were assessed using the Kaplan-Meier method and Cox proportional-hazards models without formal statistical testing and adjustment for multiplicity. Participating Asian patients received once-daily apalutamide 240 mg ( n = 111) or placebo ( n = 110) plus ADT. After a median follow-up of 42.5 months and despite crossover of 47 placebo recipients to open-label apalutamide, apalutamide reduced the risk of death by 32% (hazard ratio [HR]: 0.68; 95% confidence interval [CI]: 0.42-1.13), risk of castration resistance by 69% (HR: 0.31; 95% CI: 0.21-0.46), PSA progression by 79% (HR: 0.21; 95% CI: 0.13-0.35) and PFS2 by 24% (HR: 0.76; 95% CI: 0.44-1.29) relative to placebo. The outcomes were comparable between subgroups with low- and high-volume disease at baseline. No new safety issues were identified. Apalutamide provides valuable clinical benefits to Asian patients with mCSPC, with an efficacy and safety profile consistent with that in the overall patient population.
Male ; Humans ; Prostatic Neoplasms/pathology* ; Androgen Antagonists/therapeutic use* ; Prostate-Specific Antigen ; Castration ; Prostatic Neoplasms, Castration-Resistant/drug therapy*

Most prostate cancers initially respond to androgen deprivation therapy (ADT). With the long-term application of ADT, localized prostate cancer will progress to castration-resistant prostate cancer (CRPC), metastatic CRPC (mCRPC), and neuroendocrine prostate cancer (NEPC), and the transcriptional network shifted. Forkhead box protein A1 (FOXA1) may play a key role in this process through multiple mechanisms. To better understand the role of FOXA1 in prostate cancer, we review the interplay among FOXA1-targeted genes, modulators of FOXA1, and FOXA1 with a particular emphasis on androgen receptor (AR) function. Furthermore, we discuss the distinct role of FOXA1 mutations in prostate cancer and clinical significance of FOXA1. We summarize possible regulation pathways of FOXA1 in different stages of prostate cancer. We focus on links between FOXA1 and AR, which may play different roles in various types of prostate cancer. Finally, we discuss FOXA1 mutation and its clinical significance in prostate cancer. FOXA1 regulates the development of prostate cancer through various pathways, and it could be a biomarker for mCRPC and NEPC. Future efforts need to focus on mechanisms underlying mutation of FOXA1 in advanced prostate cancer. We believe that FOXA1 would be a prognostic marker and therapeutic target in prostate cancer.
Humans ; Male ; Androgen Antagonists/therapeutic use* ; Androgens/metabolism* ; Hepatocyte Nuclear Factor 3-alpha/metabolism* ; Mutation ; Prostatic Neoplasms, Castration-Resistant/drug therapy* ; Receptors, Androgen/metabolism*

The relationship between androgen and prostate cancer treatment has plagued the field of urologic oncology. To investigate the efficacy and safety of bipolar androgen therapy (BAT) followed by immune checkpoint inhibitor therapy in patients with metastatic castration resistant prostate cancer (mCRPC). In August 2020, Beijing Hospital conducted an investigator-initiated study: Bipolar androgen therapy followed by immune checkpoint inhibitor therapy in metastatic castration resistant prostate cancer. Up to now, the study has included 4 patients who completed the entire cycle of treatment. The mean age of the patients was 74.5 (68 to 82) years old, the mean prostate-specific antigen (PSA) was 20.8 (9.9 to 8.36) μg/L, the mean testosterone was 0.50 (0.00 to 1.81) μg/L, and the Gleason score were 10 and 9, 7, 7 respectively. The pain scale score before treatment was 1.5 (1 to 2). In this study, 4 patients completed the entire cycle of treatment, and the treatment effect of the patients showed great heterogeneity. PSA in case 1 decreased from 24.0 μg/L to 0.47 μg/L, testosterone increased from 0.175 6 μg/L to 2.62 μg/L. PSA in case 2 increased from 9.939 μg/L to 168.536 μg/L, and testosterone increased from 0.0 μg/L increased to 2.85 μg/L. PSA increased from 13.31 μg/L to 39.278 μg/L in case 3, testosterone increased from 0.0 μg/L to 2.54 μg/L. and PSA increased from 36.0 μg/L to 350.2 μg/L in the case 4, testosterone increased from 1.81 μg/L to 3.85 μg/L. Except for one patient who showed significant PSA remission, the PSA levels of the remaining three patients remained high overall. There were no adverse reactions reported in 4 patients. In the follow-up, case 1 continued to use PD-1 monoclonal antibody (median progression free survival time was 10 months). Two patients who had previously been resistant to enzalutamide received enzalutamide again after the whole cycle of treatment, and their PSA decreased again, which indicated that the patient was sensitive to enzalutamide again. BAT had a certain therapeutic effect on mCRPC patients, and the safety was controllable. Its tumor control effect still needed long-term follow-up verification in large-sample clinical trials. BAT has a certain therapeutic effect on mCRPC patient, especially the resensitivity of tumors to enzalutamide can be restored. Immune checkpoint inhibitors may have therapeutic potential in patients with prostate cancer treated with BAT and enzalutamide.
Aged ; Aged, 80 and over ; Androgens/therapeutic use* ; Humans ; Immune Checkpoint Inhibitors ; Male ; Nitriles/therapeutic use* ; Prostate-Specific Antigen ; Prostatic Neoplasms, Castration-Resistant/drug therapy* ; Testosterone/therapeutic use* ; Treatment Outcome

OBJECTIVE: To observe the early efficacy and toxicity of docetaxel combined with carboplatin in patients with metastatic castration-resistant prostate cancer (mCRPC). METHODS: From May 2017 to July 2019, fifteen patients with mCRPC treated in Peking University First Hospital were collected. The median age was 70 years (43-77 years), and the pathological types were all adenocarcinoma, which was confirmed as distant metastasis by imaging examination. They were given the chemotherapy of docetaxel combined with carboplatin. The specific method was as follows: each cycle was 28 days. Androgen deprivation therapy was administered routinely throughout the treatment period. Blood routine, liver and kidney function, blood clotting function and prostate-specific antigen (PSA) tests were performed before each cycle. Docetaxel was administered intravenously on the first day of each cycle at a dose of 75 mg/m², and carboplatin was administered intravenously on the second day at the dose calculated by Calvert formula. The main outcome measures including PSA decline range, pain remission rate and occurrence of adverse reactions were observed and analyzed. RESULTS: Among the 15 patients, 12 had completed at least 4 cycles of chemotherapy and had short-term efficacy evaluation. PSA decline range > 50% was observed in 8 patients (66.7%). Among the 9 patients with bone pain, remarkable pain relief was observed in 4 patients (44.4%). Among the 4 patients with measurable metastatic lesions, 2 achieved partial response, 1 was evaluated as stable disease, and 1 was evaluated as progressive disease. The main adverse reactions of chemotherapy included bone marrow suppression, gastrointestinal reactions, fatigue and neurological disorders, and most of them were within the tolerable range. CONCLUSION This report is a case series study of docetaxel combined with carboplatin in the treatment of mCRPC reported in China and the conclusions are representative. The chemotherapy of docetaxel combined with carboplatin has positive short-term efficacy and high safety in patients with mCRPC, which is worthy of further promotion and exploration in clinical practice.
Aged ; Androgen Antagonists/therapeutic use* ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; Carboplatin/therapeutic use* ; Docetaxel/therapeutic use* ; Humans ; Male ; Prostate-Specific Antigen ; Prostatic Neoplasms, Castration-Resistant/drug therapy* ; Treatment Outcome

The development and progression of metastatic castration-resistant prostate cancer is the major challenge in the treatment of advanced prostate cancer. The androgen receptor signaling pathway remains active in metastatic castration-resistant prostate cancer. Docetaxel and cabazitaxel are the first- and second-line chemotherapy, respectively, for patients with metastatic castration-resistant prostate cancer. These two taxanes, in general, function by (i) inhibiting mitosis and inducing apoptosis and (ii) preventing microtubule-dependent cargo trafficking. In prostate cancer, taxanes have been reported to inhibit the nuclear translocation and activity of the androgen receptor. However, whether this is attainable or not clinically remains controversial. In this review, we will provide a comprehensive view of the effects of taxanes on androgen receptor signaling in prostate cancer.
Antineoplastic Agents, Phytogenic/therapeutic use* ; Humans ; Male ; Prostatic Neoplasms, Castration-Resistant/drug therapy* ; Receptors, Androgen/drug effects* ; Signal Transduction/drug effects* ; Taxoids/therapeutic use*

PROSPER is an international Phase III trial demonstrating the beneficial role of enzalutamide, an androgen receptor antagonist, in prolonging metastasis-free survival in men with nonmetastatic castration-resistant prostate cancer. The trial showed that the median metastasis-free survival was 21.9 months longer for those treated with enzalutamide (36.6 months) compared to those treated with placebo (14.7 months). Enzalutamide also showed prolonged time to PSA progression, PSA response, and time to initiating additional antineoplastic therapy although overall survival is not yet reached. Enzalutamide is the second antiandrogen (next to apalutamide) that has gained the United States Food and Drug Administration (US FDA) label indication for use in the setting of nonmetastatic castration-resistant prostate cancer.
Androgen Antagonists/therapeutic use* ; Antineoplastic Agents/therapeutic use* ; Benzamides ; Humans ; Male ; Nitriles ; Phenylthiohydantoin/therapeutic use* ; Prostatic Neoplasms, Castration-Resistant/drug therapy*