Androgen receptors in hormone-dependent and castration-resistant prostate cancer

PROTACs targeting androgen receptor signaling: Potential therapeutic agents for castration-resistant prostate cancer

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.

Reciprocal regulation between RACGAP1 and AR contributes to endocrine therapy resistance in prostate cancer

BACKGROUND

Endocrine resistance driven by sustained activation of androgen receptor (AR) signaling pathway in advanced prostate cancer (PCa) is fatal. Characterization of mechanisms underlying aberrant AR pathway activation to search for potential therapeutic strategy is particularly important. Rac GTPase-activating protein 1 (RACGAP1) is one of the specific GTPase-activating proteins. As a novel tumor proto-oncogene, overexpression of RACGAP1 was related to the occurrence of various tumors.

METHODS

Bioinformatics methods were used to analyze the relationship of expression level between RACGAP1 and AR as well as AR pathway activation. qRT-PCR and western blotting assays were performed to assess the expression of AR/AR-V7 and RACGAP1 in PCa cells. Immunoprecipitation and immunofluorescence experiments were conducted to detect the interaction and co-localization between RACGAP1 and AR/AR-V7. Gain- and loss-of-function analyses were conducted to investigate the biological roles of RACGAP1 in PCa cells, using MTS and colony formation assays. In vivo experiments were conducted to evaluate the effect of RACGAP1 inhibition on the tumor growth.

RESULTS

RACGAP1 was a gene activated by AR, which was markedly upregulated in PCa patients with CRPC and enzalutamide resistance. AR transcriptionally activated RACGAP1 expression by binding to its promoter region. Reciprocally, nuclear RACGAP1 bound to the N-terminal domain (NTD) of both AR and AR-V7, blocking their interaction with the E3 ubiquitin ligase MDM2. Consequently, this prevented the degradation of AR/AR-V7 in a ubiquitin-proteasome-dependent pathway. Notably, the positive feedback loop between RACGAP1 and AR/AR-V7 contributed to endocrine therapy resistance of CRPC. Combination of enzalutamide and in vivo cholesterol-conjugated RIG-I siRNA drugs targeting RACGAP1 induced potent inhibition of xenograft tumor growth of PCa.

CONCLUSION

In summary, our results reveal that reciprocal regulation between RACGAP1 and AR/AR-V7 contributes to the endocrine resistance in PCa. These findings highlight the therapeutic potential of combined RACGAP1 inhibition and enzalutamide in treatment of advanced PCa.

Role of gut microbiota in the pathogenesis of castration-resistant prostate cancer: a comprehensive study using sequencing and animal models

CRPC remains a significant challenge in prostate cancer research. We aimed to elucidate the role of gut microbiota and its specific mechanisms in CRPC using a multidisciplinary approach. We analyzed 16S rRNA sequencing data from mouse fecal samples, revealing substantial differences in gut microbiota composition between CRPC and castration-sensitive prostate cancer mice, particularly in Firmicutes and Bacteroidetes. Functional analysis suggested different bacteria may influence CRPC via the α-linolenic acid metabolism pathway. In vivo, experiments utilizing mouse models and fecal microbiota transplantation (FMT) demonstrated that FMT from healthy control mice could decelerate tumor growth in CRPC mice, reduce TNF-α levels, and inhibit the activation of the TLR4/MyD88/NF-κB signaling pathway. Transcriptome sequencing identified crucial genes and pathways, with rescue experiments confirming the gut microbiota's role in modulating CRPC progression through the TLR4/MyD88/NF-κB pathway. The activation of this pathway by TNF-α has been corroborated by in vitro cell experiments, indicating its role in promoting prostate cancer cell proliferation, migration, and invasion while inhibiting apoptosis. Gut microbiota dysbiosis may promote CRPC development through TNF-α activation of the TLR4/MyD88/NF-κB signaling pathway, potentially linked to α-linolenic acid metabolism.

Cardiovascular Toxicity Associated With Androgen Receptor Axis-Targeted Agents in Patients With Prostate Cancer: A Meta-analysis of Randomized Controlled Trials

INTRODUCTION

Second-generation androgen receptor axis-targeting (ARAT) agents have become a standard treatment for patients with advanced prostate cancer (PC), however much remains unknown about the potential cardiovascular toxicities.

PATIENTS AND METHODS

We performed a systematic search of PubMed, Embase, Web of Science, and Cochrane library for randomized controlled trials of patients receiving ARAT agents for PC from inception to March 2023. The odds ratios (ORs) of all-grade and high-grade cardiovascular adverse events (CVAEs) for patients treated with and without ARAT agents were pooled for meta-analysis. Subgroup analyses based on PC type and treatment regimen were conducted.

RESULTS

A total of 15 double-blind placebo-controlled phase 3 trials comprising 15,842 patients were included. In addition to hot flush and hypertension of any degree of severity, inclusion of ARAT agents was associated with a significantly higher risk of acute myocardial infarction (OR: 1.96, 95% CI: 1.05-3.68, P = .04), myocardial infarction (OR: 2.44, 95% CI: 1.27-4.66, P = .007) and angina pectoris (OR: 2.00, 95% CI: 1.00-4.02, P = .05). With regard to individual ARAT agents, enzalutamide was associated with a significantly higher risk of acute myocardial infarction (OR: 3.11, 95% CI: 1.17-8.28, P = .02), coronary artery disease (OR: 8.33, 95% CI: 1.54-44.95, P = .01), and high-grade hypertension (OR: 4.94, 95% CI: 1.11-22.06, P = .04), while abiraterone and apalutamide were associated with a significantly higher risk of angina pectoris (OR: 5.48, 95% CI: 1.23-24.33, P = .03) and myocardial infarction (OR: 7.00, 95% CI: 1.60-30.62, P = .01), respectively.

CONCLUSION

The inclusion of ARAT agents was associated with a significantly higher risk of several CVAEs. Clinicians should remain vigilant, both in pre-treatment screening and monitoring for clinical symptoms and signs, when considering ARAT agent particularly for patients with pre-existing risk factors.

JMJD2A promotes the development of castration-resistant prostate cancer by activating androgen receptor enhancer and inhibiting the cGAS-STING pathway

Exploring targets for inhibiting androgen receptor (AR) activity is an effective strategy for suppressing the development of castration-resistant prostate cancer (CRPC). Upregulation of histone demethylase JMJD2A activity is an important factor in increasing AR expression in CRPC. Based on our research, we found that the binding affinity between JMJD2A and AR increases in CRPC, while the level of AR histone methylation decreases and the H3K27ac level increases in the AR enhancer region. Further investigations revealed that overexpression of the histone demethylase JMJD2A increased the binding affinity between JMJD2A and AR, decreased AR histone methylation levels, upregulated H3K27ac in the AR enhancer region, and increased AR activity. Conversely, knocking down JMJD2A effectively reversed these effects. Additionally, in CRPC, JMJD2A expression was upregulated, the tumor-intrinsic immune cGAS-STING signaling pathway was suppressed, the tumor microenvironment was altered, and AR expression was upregulated. However, both knocking down JMJD2A and inhibiting the cyclic GMP-AMP synthase/stimulator of interferon genes (cGAS-STING) signaling pathway reversed these effects. In summary, our study indicates that in CRPC, JMJD2A can directly bind to AR and activate residual AR enhancers through its demethylation activity, thereby promoting AR expression. Furthermore, upregulation of JMJD2A expression inhibits the innate immune cGAS-STING signaling pathway of the tumor, leading to a decrease in antitumor immune function, and further promoting AR expression.

Insulin-like growth factor family and prostate cancer: new insights and emerging opportunities

Prostate cancer is the second most commonly diagnosed cancer in men. The mammalian insulin-like growth factor (IGF) family is made up of three ligands (IGF-I, IGF-II, and insulin), three receptors (IGF-I receptor (IGF-1R), insulin receptor (IR), and IGF-II receptor (IGF-2R)), and six IGF-binding proteins (IGFBPs). IGF-I and IGF-II were identified as potent mitogens and were previously associated with an increased risk of cancer development including prostate cancer. Several reports showed controversy about the expression of the IGF family and their connection to prostate cancer risk due to the high degree of heterogeneity among prostate tumors, sampling bias, and evaluation techniques. Despite that, it is clear that several IGF family members play a role in prostate cancer development, metastasis, and androgen-independent progression. In this review, we aim to expand our understanding of prostate tumorigenesis and regulation through the IGF system. Further understanding of the role of IGF signaling in PCa shows promise and needs to be considered in the context of a comprehensive treatment strategy.

Sequence of androgen receptor-targeted vaccination with androgen deprivation therapy affects anti-prostate tumor efficacy

RATIONALE

Androgen deprivation therapy (ADT) is the primary treatment for recurrent and metastatic prostate cancer. In addition to direct antitumor effects, ADT has immunomodulatory effects such as promoting T-cell infiltration and enhancing antigen processing/presentation. Previous studies in our laboratory have demonstrated that ADT also leads to increased expression of the androgen receptor (AR) and increased recognition of prostate tumor cells by AR-specific CD8+T cells. We have also demonstrated that ADT combined with a DNA vaccine encoding the AR significantly slowed tumor growth and improved the survival of prostate tumor-bearing mice. The current study aimed to investigate the impact of the timing and sequencing of ADT with vaccination on the tumor immune microenvironment in murine prostate cancer models to further increase the antitumor efficacy of vaccines.

METHODS

Male FVB mice implanted with Myc-CaP tumor cells, or male C57BL/6 mice implanted with TRAMP-C1 prostate tumor cells, were treated with a DNA vaccine encoding AR (pTVG-AR) and ADT. The sequence of administration was evaluated for its effect on tumor growth, and tumor-infiltrating immune populations were characterized.

RESULTS

Vaccination prior to ADT (pTVG-AR → ADT) significantly enhanced antitumor responses and survival. This was associated with increased tumor infiltration by CD4+ and CD8+ T cells, including AR-specific CD8+T cells. Depletion of CD8+T cells prior to ADT significantly worsened overall survival. Following ADT treatment, however, Gr1+ myeloid-derived suppressor cells (MDSCs) increased, and this was associated with fewer infiltrating T cells and reduced tumor growth. Inhibiting Gr1+MDSCs recruitment, either by using a CXCR2 antagonist or by cycling androgen deprivation with testosterone replacement, improved antitumor responses and overall survival.

CONCLUSION

Vaccination prior to ADT significantly improved antitumor responses, mediated in part by increased infiltration of CD8+T cells following ADT. Targeting MDSC recruitment following ADT further enhanced antitumor responses. These findings suggest logical directions for future clinical trials to improve the efficacy of prostate cancer vaccines.

AR coactivators, CBP/p300, are critical mediators of DNA repair in prostate cancer

Castration resistant prostate cancer (CRPC) remains an incurable disease stage with ineffective treatments options. Here, the androgen receptor (AR) coactivators CBP/p300, which are histone acetyltransferases, were identified as critical mediators of DNA damage repair (DDR) to potentially enhance therapeutic targeting of CRPC. Key findings demonstrate that CBP/p300 expression increases with disease progression and selects for poor prognosis in metastatic disease. CBP/p300 bromodomain inhibition enhances response to standard of care therapeutics. Functional studies, CBP/p300 cistrome mapping, and transcriptome in CRPC revealed that CBP/p300 regulates DDR. Further mechanistic investigation showed that CBP/p300 attenuation via therapeutic targeting and genomic knockdown decreases homologous recombination (HR) factors in vitro, in vivo, and in human prostate cancer (PCa) tumors ex vivo. Similarly, CBP/p300 expression in human prostate tissue correlates with HR factors. Lastly, targeting CBP/p300 impacts HR-mediate repair and patient outcome. Collectively, these studies identify CBP/p300 as drivers of PCa tumorigenesis and lay the groundwork to optimize therapeutic strategies for advanced PCa via CBP/p300 inhibition, potentially in combination with AR-directed and DDR therapies.

Role of extracellular vesicles in castration-resistant prostate cancer

Prostate cancer (PCa) is a common health threat to men worldwide, and castration-resistant PCa (CRPC) is the leading cause of PCa-related deaths. Extracellular vesicles (EVs) are lipid bilayer compartments secreted by living cells that are important mediators of intercellular communication. EVs regulate the biological processes of recipient cells by transmitting heterogeneous cargoes, contributing to CRPC occurrence, progression, and drug resistance. These EVs originate not only from malignant cells, but also from various cell types within the tumor microenvironment. EVs are widely dispersed throughout diverse biological fluids and are attractive biomarkers derived from noninvasive liquid biopsy techniques. EV quantities and cargoes have been tested as potential biomarkers for CRPC diagnosis, progression, drug resistance, and prognosis; however, technical barriers to their clinical application continue to exist. Furthermore, exogenous EVs may provide tools for new therapies for CRPC. This review summarizes the current evidence on the role of EVs in CRPC.

Assessment of structural and activity-related contributions of various PIM-1 kinase inhibitors in the treatment of leukemia and prostate cancer

One of the most perilous illnesses in the world is cancer. The cancer may be associated with the mutation of different genes inside the body. The PIM kinase, also known as the serine/threonine kinase, plays a critical role in the biology of different kinds of cancer. They are widely distributed and associated with several biological processes, including cell division, proliferation, and death. Aberration of PIM-1 kinase is found in varieties of cancer. Prostate cancer and leukemia can both be effectively treated with PIM-1 kinase inhibitors. There are several potent compounds that have been explored in this review based on heterocyclic compounds for the treatment of prostate cancer and leukemia that have strong effects on the suppression of PIM-1 kinase. The present review summarizes the PIM-1 kinase pathway, their inhibitors under clinical trial, related patents, and SAR studies of several monocyclic, bicyclic, and polycyclic compounds. The study related to their molecular interactions with receptors is also included in the present manuscript. The study may be beneficial to scientists for the development of novel compounds as PIM-1 inhibitors in the treatment of prostate cancer and leukemia.

The hidden messengers: cancer associated fibroblasts-derived exosomal miRNAs as key regulators of cancer malignancy

Cancer-associated fibroblasts (CAFs), a class of stromal cells in the tumor microenvironment (TME), play a key role in controlling cancer cell invasion and metastasis, immune evasion, angiogenesis, and resistance to chemotherapy. CAFs mediate their activities by secreting soluble chemicals, releasing exosomes, and altering the extracellular matrix (ECM). Exosomes contain various biomolecules, such as nucleic acids, lipids, and proteins. microRNA (miRNA), a 22-26 nucleotide non-coding RNA, can regulate the cellular transcription processes. Studies have shown that miRNA-loaded exosomes secreted by CAFs engage in various regulatory communication networks with other TME constituents. This study focused on the roles of CAF-derived exosomal miRNAs in generating cancer malignant characteristics, including immune modulation, tumor growth, migration and invasion, epithelial-mesenchymal transition (EMT), and treatment resistance. This study thoroughly examines miRNA's dual regulatory roles in promoting and suppressing cancer. Thus, changes in the CAF-derived exosomal miRNAs can be used as biomarkers for the diagnosis and prognosis of patients, and their specificity can be used to develop newer therapies. This review also discusses the pressing problems that require immediate attention, aiming to inspire researchers to explore more novel avenues in this field.

CRISPR genome-wide screening identifies PAK1 as a critical driver of ARSI cross-resistance in prostate cancer progression

Next-generation androgen receptor signaling inhibitors (ARSIs), such as enzalutamide (Enza) and darolutamide (Daro), are initially effective for the treatment of advanced prostate cancer (PCa) and castration-resistant prostate cancer (CRPC). However, patients often relapse and develop cross-resistance, which consequently makes drug resistance an inevitable cause of CRPC-related mortality. By conducting a comprehensive analysis of GEO datasets, CRISPR genome-wide screening results, ATAC-seq data, and RNA-seq data, we systemically identified PAK1 as a significant contributor to ARSI cross-resistance due to the activation of the PAK1/RELA/hnRNPA1/AR-V7 axis. Inhibition of PAK1 followed by suppression of NF-κB pathways and AR-V7 expression effectively overcomes ARSI cross-resistance. Our findings indicate that PAK1 represents a promising therapeutic target gene for the treatment of ARSI cross-resistant PCa patients in the clinic. STATEMENT OF SIGNIFICANCE: PAK1 drives ARSI cross-resistance in prostate cancer progression.

Enzalutamide induces cytotoxicity in desmoplastic small round cell tumor independent of the androgen receptor

Desmoplastic Small Round Cell Tumor (DSRCT) is a rare, pediatric cancer caused by the EWSR1::WT1 fusion protein. DSRCT predominantly occurs in males, which comprise 80-90% of the patient population. While the reason for this male predominance remains unknown, one hypothesis is that the androgen receptor (AR) plays a critical role in DSRCT and elevated testosterone levels in males help drive tumor growth. Here, we demonstrate that AR is highly expressed in DSRCT relative to other fusion-driven sarcomas and that the AR antagonists enzalutamide and flutamide reduce DSRCT growth. However, despite these findings, which suggest an important role for AR in DSRCT, we show that DSRCT cell lines form xenografts in female mice at the same rate as male mice and AR depletion does not significantly alter DSRCT growth in vitro. Further, we find that AR antagonists reduce DSRCT growth in cells depleted of AR, establishing an AR-independent mechanism of action. These findings suggest that AR dependence is not the reason for male predominance in DSRCT and that AR-targeted therapies may provide therapeutic benefit primarily through an AR-independent mechanism that requires further elucidation.

Discovery of a novel natural compound, vitekwangin B, with ANO1 protein reduction properties and anticancer potential

Background: Prostate cancer and non-small cell lung cancer (NSCLC) present significant challenges in the development of effective therapeutic strategies. Hormone therapies for prostate cancer target androgen receptors and prostate-specific antigen markers. However, treatment options for prostatic small-cell neuroendocrine carcinoma are limited. NSCLC, on the other hand, is primarily treated with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors but exhibits resistance. This study explored a novel therapeutic approach by investigating the potential anticancer properties of vitekwangin B, a natural compound derived from Vitex trifolia. Methods: Vitekwangin B was chromatographically isolated from the fruits of V. trifolia. ANO1 protein levels in prostate cancer and NSCLC cells were verified and evaluated again after vitekwangin B treatment. Results: Vitekwangin B did not inhibit anoctamin1 (ANO1) channel function but significantly reduced ANO1 protein levels. These results demonstrate that vitekwangin B effectively inhibited cancer cell viability and induced apoptosis in prostate cancer and NSCLC cells. Moreover, it exhibited minimal toxicity to liver cells and did not affect hERG channel activity, making it a promising candidate for further development as an anticancer drug. Conclusion: Vitekwangin B may offer a new direction for cancer therapy by targeting ANO1 protein, potentially improving treatment outcomes in patients with prostate cancer and NSCLC. Further research is needed to explore its full potential and overcome existing drug resistance challenges.

Silencing of matrix metalloprotease-12 delays the progression of castration-resistant prostate cancer by regulating autophagy and lipolysis

The complex pathogenesis of castration-resistant prostate cancer (CRPC) makes it challenging to identify effective treatment methods. Matrix metalloproteinase (MMP)-12 can degrade elastin as well as various extracellular matrix (ECM) components, which is associated with cancer progression. However, the relationship between MMP-12 and CRPC progression is poorly understood. In this study, we observed the effect of MMP-12 on the progression of CRPC and further explored its potential mechanism of action. High levels of MMP-12 were observed in patients with CRPC. We therefore developed cell co-culture and mouse models to study the function of MMP-12. Silencing MMP-12 in CRPC cells disrupted lipid utilization and autophagy marker expression via the CD36/CPT1 and P62/LC3 pathways, respectively, leading to reduced CRPC cell migration and invasion. Moreover, animal experiments confirmed that MMP-12-knockdown CRPC xenograft tumors exhibited reduced tumor growth, and the mechanisms involved the promotion of cancer cell autophagy and the inhibition of lipid catabolism. According to our results, MMP-12 played important roles in the progression of CRPC by disrupting adipocyte maturation and regulating cancer migration and invasion via the modulation of autophagy and lipid catabolism pathways.

Resistance Exercise Training, a Simple Intervention to Preserve Muscle Mass and Strength in Prostate Cancer Patients on Androgen Deprivation Therapy

Androgen deprivation therapy (ADT) forms the cornerstone in the treatment of advanced prostate cancer. However, by suppressing testosterone ADT results in a decrease of skeletal muscle mass. In this narrative review, we explore the magnitude and mechanisms of ADT-induced muscle mass loss and the consequences for muscle strength and physical performance. Subsequently, we elucidate the effectiveness of supervised resistance exercise training as a means to mitigate these adverse effects. Literature shows that resistance exercise training can effectively counteract ADT-induced loss of appendicular lean body mass and decline in muscle strength, while the effect on physical performances is inconclusive. As resistance exercise training is feasible and can be safely implemented during ADT (with special attention for patients with bone metastases), it should be incorporated in standard clinical care for prostate cancer patients (starting) with ADT.

Genetic variant in a BaP-activated super-enhancer increases prostate cancer risk by promoting AhR-mediated FAM227A expression

Genetic variants in super-enhancers (SEs) are increasingly implicated as a disease risk-driving mechanism. Previous studies have reported an associations between benzo[a]pyrene (BaP) exposure and some malignant tumor risk. Currently, it is unclear whether BaP is involved in the effect of genetic variants in SEs on prostate cancer risk, nor the associated intrinsic molecular mechanisms. In the current study, by using logistic regression analysis, we found that rs5750581T>C in 22q-SE was significantly associated with prostate cancer risk (odds ratio = 1.26, P = 7.61 × 10 -5). We also have found that the rs6001092T>G, in a high linkage disequilibrium with rs5750581T>C ( r 2 = 0.98), is located in a regulatory aryl hydrocarbon receptor (AhR) motif and may interact with the FAM227A promoter in further bioinformatics analysis. We then performed a series of functional and BaP acute exposure experiments to assess biological function of the genetic variant and the target gene. Biologically, the rs6001092-G allele strengthened the transcription factor binding affinity to AhR, thereby upregulating FAM227A, especially upon exposure to BaP, which induced the malignant phenotypes of prostate cancer. The current study highlights that AhR acts as an environmental sensor of BaP and is involved in the SE-mediated prostate cancer risk, which may provide new insights into the etiology of prostate cancer associated with the inherited SE variants under environmental carcinogen stressors.

Estrogen receptor beta suppresses the androgen receptor oncogenic effects in triple-negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC) is an aggressive type of breast cancer associated with poor prognosis and limited treatment options. The androgen receptor (AR) has emerged as a potential therapeutic target for luminal androgen receptor (LAR) TNBC. However, multiple studies have claimed that anti-androgen therapy for AR-positive TNBC only has limited clinical benefits. This study aimed to investigate the role of AR in TNBC and its detailed mechanism.

METHODS

Immunohistochemistry and TNBC tissue sections were applied to investigate AR and nectin cell adhesion molecule 4 (NECTIN4) expression in TNBC tissues. Then, in vitro and in vivo assays were used to explore the function of AR and estrogen receptor beta (ERβ) in TNBC. Chromatin immunoprecipitation sequencing (ChIP-seq), co-immunoprecipitation (co-IP), molecular docking method, and luciferase reporter assay were performed to identify key molecules that affect the function of AR.

RESULTS

Based on the TNBC tissue array analysis, we revealed that ERβ and AR were positive in 21.92% (32/146) and 24.66% (36/146) of 146 TNBC samples, respectively, and about 13.70% (20/146) of TNBC patients were ERβ positive and AR positive. We further demonstrated the pro-tumoral effects of AR on TNBC cells, however, the oncogenic biology was significantly suppressed when ERβ transfection in LAR TNBC cell lines but not in AR-negative TNBC. Mechanistically, we identified that NECTIN4 promoter -42 bp to -28 bp was an AR response element, and that ERβ interacted with AR thus impeding the AR-mediated NECTIN4 transcription which promoted epithelial-mesenchymal transition in tumor progression.

CONCLUSIONS

This study suggests that ERβ functions as a suppressor mediating the effect of AR in TNBC prognosis and cell proliferation. Therefore, our current research facilitates a better understanding of the role and mechanisms of AR in TNBC carcinogenesis.

H3K27 acetylation activated-PDLIM7 promotes castration-resistant prostate cancer progression by inducing O-Glycosylation of YAP1 protein

Castration-resistant prostate cancer (CRPC) is a fatal disease that evolves from prostate cancer due to drug resistance after long-term androgen deprivation therapy. In this study, we aimed to find novel molecular targets for treating CRPC. Through peptidome, we screened out polypeptides dysregulated in the serum of CRPC patients. According to RT-qPCR analysis and cell viability detection, we chose PDZ and LIM Domain 7 (PDLIM7) as the research object. As demonstrated by loss-of-function assays, silencing of PDLIM7 could suppress CRPC cell proliferation, migration, and angiogenesis. Moreover, PDLIM7 knockdown enhanced the sensitivity of CRPC cells to docetaxel treatment. Subsequently, we found that CBP/p300 increases the H3K27ac level in the PDLIM7 promoter to activate PDLIM7. Mechanism experiments such as IP and western blot revealed that PDLIM7 interacted with YAP1 to induce O-Glycosylation of YAP1 and thus stabilize YAP1 protein. Rescue assays demonstrated that PDLIM7 promoted the malignant processes of CRPC cells through YAP1. Finally, an animal study validated that PDLIM7 aggravated tumor growth. In conclusion, our findings highlighted the oncogenic role of PDLIM7 upregulated by CBP/p300-induced H3K27ac enhancement in CRPC by stabilizing YAP1.

Synthesis and application of clinically approved small-molecule drugs targeting androgen receptor

Androgen receptor (AR) plays a crucial role in various physiological processes. Dysregulation of AR signaling has been implicated in several diseases, such as prostate cancer and androgenetic alopecia. Therefore, the development of drugs that specifically target AR has gained significant attention in the field of drug discovery. This review provides an overview of the synthetic routes of clinically approved small molecule drugs targeting AR and discusses the clinical applications of these drugs in the treatment of AR-related diseases. The review also highlights the challenges and future perspectives in this field, including the need for improved drug design and the exploration of novel therapeutic targets. Through an integrated analysis of the therapeutic applications, synthetic methodologies, and mechanisms of action associated with these approved drugs, this review facilitates a holistic understanding of the versatile roles and therapeutic potential of AR-targeted interventions. Overall, this comprehensive review serves as a valuable resource for medicinal chemists interested in the development of small-molecule drugs targeting AR.

Canonical and Nuclear mTOR Specify Distinct Transcriptional Programs in Androgen-Dependent Prostate Cancer Cells

mTOR is a serine/threonine kinase that controls prostate cancer cell growth in part by regulating gene programs associated with metabolic and cell proliferation pathways. mTOR-mediated control of gene expression can be achieved via phosphorylation of transcription factors, leading to changes in their cellular localization and activities. mTOR also directly associates with chromatin in complex with transcriptional regulators, including the androgen receptor (AR). Nuclear mTOR (nmTOR) has been previously shown to act as a transcriptional integrator of the androgen signaling pathway in association with the chromatin remodeling machinery, AR, and FOXA1. However, the contribution of cytoplasmic mTOR (cmTOR) and nmTOR and the role played by FOXA1 in this process remains to be explored. Herein, we engineered cells expressing mTOR tagged with nuclear localization and export signals dictating mTOR localization. Transcriptome profiling in AR-positive prostate cancer cells revealed that nmTOR generally downregulates a subset of the androgen response pathway independently of its kinase activity, while cmTOR upregulates a cell cycle-related gene signature in a kinase-dependent manner. Biochemical and genome-wide transcriptomic analyses demonstrate that nmTOR functionally interacts with AR and FOXA1. Ablation of FOXA1 reprograms the nmTOR cistrome and transcriptome of androgen responsive prostate cancer cells. This works highlights a transcriptional regulatory pathway in which direct interactions between nmTOR, AR and FOXA1 dictate a combinatorial role for these factors in the control of specific gene programs in prostate cancer cells.

IMPLICATIONS

The finding that canonical and nuclear mTOR signaling pathways control distinct gene programs opens therapeutic opportunities to modulate mTOR activity in prostate cancer cells.

The microRNA-193a-5p induced ROS production and disturbed colocalization between STAT3 and androgen receptor play critical roles in cornin induced apoptosis

Though cornin is known to induce angiogenic, cardioprotective, and apoptotic effects, the apoptotic mechanism of this iridoid monoglucoside is not fully understood in prostate cancer cells to date. To elucidate the antitumor mechanism of cornin, cytotoxicity assay, cell cycle analysis, Western blotting, RT-qPCR, RNA interference, immunofluorescence, immunoprecipitation, reactive oxygen species (ROS) measurement, and inhibitor assay were applied in this work. Cornin exerted cytotoxicity, increased sub-G1 population, and cleaved PARP and caspase3 in LNCaP cells more than in DU145 cells. Consistently, cornin suppressed phosphorylation of signal transducer and activator of transcription 3 (STAT3) and disrupted the colocalization of STAT3 and androgen receptor (AR) in LNCaP and DU145 cells, along with suppression of AR, prostate-specific antigen (PSA), and 5α-reductase in LNCaP cells. Furthermore, cornin increased ROS production and the level of miR-193a-5p, while ROS inhibitor N-acetylcysteine disturbed the ability of cornin to attenuate the expression of AR, p-STAT3, PSA, pro-PARP, and pro-caspase3 in LNCaP cells. Notably, miR-193a-5p mimics the enhanced apoptotic effect of cornin, while miR-193a-5p inhibitor reverses the ability of cornin to abrogate AR, PSA, and STAT3 in LNCaP cells. Our findings suggest that ROS production and the disturbed crosstalk between STAT3 and AR by microRNA-193a-5p are critically involved in the apoptotic effect of cornin in prostate cancer cells.

Acquired copy number variation in prostate tumours: a review of common somatic copy number alterations, how they are formed and their clinical utility

Prostate cancer is one of the most commonly diagnosed cancers in men and unfortunately, disease will progress in up to a third of patients despite primary treatment. Currently, there is a significant lack of prognostic tests that accurately predict disease course; however, the acquisition of somatic chromosomal variation in the form of DNA copy number variants may help understand disease progression. Notably, studies have found that a higher burden of somatic copy number alterations (SCNA) correlates with more aggressive disease, recurrence after surgery and metastasis. Here we will review the literature surrounding SCNA formation, including the roles of key tumour suppressors and oncogenes (PTEN, BRCA2, NKX3.1, ERG and AR), and their potential to inform diagnostic and prognostic clinical testing to improve predictive value. Ultimately, SCNAs, or inherited germline alterations that predispose to SCNAs, could have significant clinical utility in diagnostic and prognostic tests, in addition to guiding therapeutic selection.

Discovery of the First-in-Class RORγ Covalent Inhibitors for Treatment of Castration-Resistant Prostate Cancer

Nuclear receptor receptor-related orphan receptor γ (RORγ) is a ligand-dependent transcription factor and has been established as a key player in castration-resistant prostate cancers (CRPC) by driving androgen receptor (AR) overexpression, representing a potential therapeutical target for advanced prostate cancers. Here, we report the identification of the first-in-class RORγ covalent inhibitor 29 via the structure-based drug design approach following structure-activity relationship (SAR) exploration. Mass spectrometry assay validated its covalent inhibition mechanism. Compound 29 significantly inhibited RORγ transcriptional activity and remarkably suppressed the expression levels of AR and AR-targeted genes. Compound 29 also exhibited much superior activity in inhibiting the proliferation and colony formation and inducing apoptosis of the CRPC cell lines relative to the positive control 2 and noncovalent control 33. Importantly, it markedly suppressed the tumor growth in a 22Rv1 mouse tumor xenograft model with good safety. These results clearly demonstrate that 29 is a highly potent and selective RORγ covalent inhibitor.

Two somatic mutations in the androgen receptor N-terminal domain are oncogenic drivers in hepatocellular carcinoma

The androgen receptor (AR) plays an important role in male-dominant hepatocellular carcinoma, and specific acquired somatic mutations of AR have been observed in HCC patients. Our previous research have established the role of AR wild type as one of the key oncogenes in hepatocarcinogenesis. However, the role of hepatic acquired somatic mutations of AR remains unknown. In this study, we identify two crucial acquired somatic mutations, Q62L and E81Q, situated close to the N-terminal activation function domain-1 of AR. These mutations lead to constitutive activation of AR, both independently and synergistically with androgens, making them potent driver oncogene mutations. Mechanistically, these N-terminal AR somatic mutations enhance de novo lipogenesis by activating sterol regulatory element-binding protein-1 and promote glycogen accumulation through glycogen phosphorylase, brain form, thereby disrupting the AMPK pathway and contributing to tumorigenesis. Moreover, the AR mutations show sensitivity to the AMPK activator A769662. Overall, this study establishes the role of these N- terminal hepatic mutations of AR as highly malignant oncogenic drivers in hepatocarcinogenesis and highlights their potential as therapeutic targets for patients harboring these somatic mutations.

Targeting DGAT1 inhibits prostate cancer cells growth by inducing autophagy flux blockage via oxidative stress

Impaired macroautophagy/autophagy flux has been implicated in the treatment of prostate cancer (PCa). However, the mechanism underlying autophagy dysregulation in PCa remains unknown. In the current study, we investigated the role of diacylglycerol acyltransferases 1 (DGAT1) and its potential effects on cellular energy homeostasis and autophagy flux in PCa. The results of immunohistochemical staining suggested that DGAT1 expression was positively corrected with tumor stage and node metastasis, indicating DGAT1 is an important factor involved in the development and progression of PCa. Furthermore, targeting DGAT1 remarkably inhibited cell proliferation in vitro and suppressed PCa growth in xenograft models by triggering severe oxidative stress and subsequently autophagy flux blockage. Mechanically, DGAT1 promoted PCa progression by maintaining cellular energy homeostasis, preserving mitochondrial function, protecting against reactive oxygen species, and subsequently promoting autophagy flux via regulating lipid droplet formation. Moreover, we found that fenofibrate exhibits as an upstream regulator of DGAT1. Fenofibrate performed its anti-PCa effect involved the aforementioned mechanisms, and partially dependent on the regulation of DGAT1. Collectively. These findings indicate that DGAT1 regulates PCa lipid droplets formation and is essential for PCa progression. Targeting DGAT1 might be a promising method to control the development and progression of PCa. Schematic representation of DGAT1 affects autophagy flux by regulating lipid homeostasis and maintaining mitochondrial function in prostate cancer (PCa). PCa is characterized up-regulation of DGAT1, leading to the translocation of free fatty acids into lipid droplets, thereby preventing PCa cell from lipotoxicity. Inhibition of DGAT1 suppresses growth of PCa by inducing oxidative stress and subsequently autophagy flux blockage. Further, the current results revealed that fenofibrate exhibits as an upstream regulator of DGAT1, and fenofibrate plays an anti-PCa role partially dependent on the regulation of DGAT1, suggesting a potential therapeutic approach to ameliorate this refractory tumor.

YTHDF1 in Tumor Cell Metabolism: An Updated Review

With the advancement of research on m6A-related mechanisms in recent years, the YTHDF protein family within m6A readers has garnered significant attention. Among them, YTHDF1 serves as a pivotal member, playing a crucial role in protein translation, tumor proliferation, metabolic reprogramming of various tumor cells, and immune evasion. In addition, YTHDF1 also exerts regulatory effects on tumors through multiple signaling pathways, and numerous studies have confirmed its ability to assist in the reprogramming of the tumor cell-related metabolic processes. The focus of research on YTHDF1 has shifted in recent years from its m6A-recognition and -modification function to the molecular mechanisms by which it regulates tumor progression, particularly by exploring the regulatory factors that interact with YTHDF1 upstream and downstream. In this review, we elucidate the latest signaling pathway mechanisms of YTHDF1 in various tumor cells, with a special emphasis on its distinctive characteristics in tumor cell metabolic reprogramming. Furthermore, we summarize the latest pathological and physiological processes involving YTHDF1 in tumor cells, and analyze potential therapeutic approaches that utilize YTHDF1. We believe that YTHDF1 represents a highly promising target for future tumor treatments and a novel tumor biomarker.

Discovery of Potent, Selective, and Orally Bioavailable DYRK2 Inhibitors for the Treatment of Prostate Cancer

Prostate cancer (PCa) seriously threatens male health, and targeting dual-specificity tyrosine phosphorylation-regulated kinase 2 (DYRK2) has been verified to reduce PCa burden, while the research progress on the DYRK2 inhibitors was relatively slow. In this work, we discovered DYRK2 inhibitor 12 (IC50 = 9681 nM) through virtual screening. Subsequently, we performed systematic structural optimization to obtain 54 (IC50 = 14 nM). Compound 54 exhibited high selectivity among 215 kinases and significantly suppressed the proliferation and metastasis of PCa cells in vitro. Moreover, compound 54 displayed high safety, favorable bioavailability, and potent tumor growth inhibitory activity in vivo, which could be used as a potential candidate in the discovery of novel anti-PCa drugs.

Silencing HOXC13 exerts anti-prostate cancer effects by inducing DNA damage and activating cGAS/STING/IRF3 pathway

BACKGROUND

Advanced prostate cancer (PCa) will develop into castration-resistant prostate cancer (CRPC) and lead to poor prognosis. As the primary subtype of CRPC, CRPC-AR accounts for the major induction of PCa heterogeneity. CRPC-AR is mainly driven by 25 transcription factors (TFs), which we speculate may be the key factors driving PCa toward CRPC. Therefore, it is necessary to clarify the key regulator and its molecular mechanism mediating PCa progression.

METHODS

Firstly, we downloaded transcriptomic data and clinical information from TCGA-PRAD. The characteristic gene cluster was identified by PPI clustering, GO enrichment, co-expression correlation and clinical feature analyses for 25 TFs. Then, the effects of 25 TFs expression on prognosis of PCa patients was analyzed using univariate Cox regression, and the target gene was identified. The expression properties of the target gene in PCa tissues were verified using tissue microarray. Meanwhile, the related mechanistic pathway of the target gene was mined based on its function. Next, the target gene was silenced by small interfering RNAs (siRNAs) for cellular function and mechanistic pathway validation. Finally, CIBERSORT algorithm was used to analyze the infiltration levels of 22 immune cells in PCa patients with low and high expression of target gene, and validated by assaying the expression of related immunomodulatory factor.

RESULTS

We found that HOX family existed independently in 25 TFs, among which HOXC10, HOXC12 and HOXC13 had unique clinical features and the PCa patients with high HOXC13 expression had the worst prognosis. In addition, HOXC13 was highly expressed in tumor tissues and correlated with Gleason score and pathological grade. In vitro experiments demonstrated that silencing HOXC13 inhibited 22RV1 and DU145 cell function by inducing cellular DNA damage and activating cGAS/STING/IRF3 pathway. Immune infiltration analysis revealed that high HOXC13 expression suppressed infiltration of γδ T cells and plasma cells and recruited M2 macrophages. Consistent with these results, silencing HOXC13 up-regulated the transcriptional expression of IFN-β, CCL2, CCL5 and CXCL10.

CONCLUSION

HOXC13 regulates PCa progression by mediating the DNA damage-induced cGAS/STING/IRF3 pathway and remodels TIME through regulation of the transcription of the immune factors IFN-β, CCL2, CCL5 and CXCL10.

Genetic evidence supporting a causal role of Janus kinase 2 in prostate cancer: a Mendelian randomization study

BACKGROUND

Janus kinase-2 (JAK2) inhibitors are now being tried in basic research and clinical practice in prostate cancer (PCa). However, the causal relationship between JAK2 and PCa has not been uniformly described. Here, we examined the cause-effect relation between JAK2 and PCa.

METHODS

Two-sample Mendelian randomization (MR) analysis of genetic variation data of JAK2, PCa from IEU OpenGWAS Project was performed by inverse variance weighted, MR-Egger, and weighted median. Cochran's Q heterogeneity test and MR-Egger multiplicity analysis were performed to normalize the MR analysis results to reduce the effect of bias on the results.

RESULTS

Five instrumental variables were identified for further MR analysis. Specifically, combining the inverse variance-weighted (OR: 1.0009, 95% CI: 1.0001-1.0015, p = 0.02) and weighted median (OR: 1.0009, 95% CI: 1.0000-1.0017, p = 0.03). Sensitivity analysis showed that there was no heterogeneity (p = 0.448) and horizontal multiplicity (p = 0.770) among the instrumental variables.

CONCLUSIONS

We found JAK2 was associated with the development of PCa and was a risk factor for PCa, which might be instructive for the use of JAK2 inhibitors in PCa patients.

Enzalutamide Induces Cytotoxicity in Desmoplastic Small Round Cell Tumor Independent of the Androgen Receptor

Desmoplastic Small Round Cell Tumor (DSRCT) is a rare, pediatric cancer caused by the EWSR1::WT1 fusion protein. DSRCT predominantly occurs in males, which comprise 80-90% of the patient population. While the reason for this male predominance remains unknown, one hypothesis is that the androgen receptor (AR) plays a critical role in DSRCT and elevated testosterone levels in males help drive tumor growth. Here, we demonstrate that AR is highly expressed in DSRCT relative to other fusion-driven sarcomas and that the AR antagonists enzalutamide and flutamide reduce DSRCT growth. However, despite these findings, which suggest an important role for AR in DSRCT, we show that DSRCT cell lines form xenografts in female mice at the same rate as male mice and AR depletion does not significantly alter DSRCT growth in vitro. Further, we find that AR antagonists reduce DSRCT growth in cells depleted of AR, establishing an AR-independent mechanism of action. These findings suggest that AR dependence is not the reason for male predominance in DSRCT and that AR-targeted therapies may provide therapeutic benefit primarily through an AR-independent mechanism that requires further elucidation.

Androgen Receptor Signaling in Prostate Cancer Genomic Subtypes

Prostate cancer (PCa) constitutes a significant cause of mortality, with over 37,000 new deaths each year [...].

Cardiovascular Adverse Events Associated With New-Generation Androgen Receptor Pathway Inhibitors (ARPI) for Prostate Cancer: A Disproportionality Analysis Based on the FDA Adverse Event Reporting System (FAERS)

BACKGROUND

The potential cardiovascular adverse events associated with new-generation androgen receptor pathway inhibitors (ARPI) in the treatment of prostate cancer remain unclear. We aimed to assess the pharmacovigilance (PV), reporting rate, severity, and reaction outcomes of major adverse cardiovascular events (MACE) related to new-generation ARPI for prostate cancer reported to the United States Food and Drug Administration Adverse Event Reporting System (FAERS).

METHODS

We analyzed reports of cardiovascular adverse events associated with drug therapy for prostate cancer submitted to FAERS between January 2014 and December 2022. Three primary new-generation ARPIs were identified: abiraterone acetate, enzalutamide, and apalutamide. Our primary composite endpoint was the PV of MACE caused by ARPIs in the treatment of prostate cancer, and the secondary endpoint was PV of other cardiovascular events. The software implemented was STATA 17.0 MP.

RESULTS

A total of 278,031 suspected drug-adverse event pairs related to drug treatment in patients with prostate cancer were identified, of which 10,861 reports were cardiovascular events, including 5800 reports of MACE and 5061 reports of other cardiovascular events. The majority of these cardiovascular adverse event reports came from the United States (36.6%) and were mostly older men (age 76.0 ± 8.6 years). Compared with enzalutamide, the constituent ratio of MACE caused by abiraterone acetate and apalutamide was significantly increased, but the incidence of severe MACE decreased significantly. The PV signal regarding MACE was detected in abiraterone acetate and apalutamide but not in enzalutamide.

CONCLUSION

Abiraterone acetate and apalutamide presumably are associated with a higher risk of MACE than enzalutamide in new-generation ARPI for prostate cancer. More extensive prospective studies and more extended follow-up periods need to confirm this further.

Unlocking the role of non-coding RNAs in prostate cancer progression: exploring the interplay with the Wnt signaling pathway

Prostate cancer (PCa) is one of the most common cancers in males, exhibiting a wide spectrum of clinical manifestations that pose challenges in its diagnosis and treatment. The Wnt signaling pathway, a conserved and complex pathway, is crucial for embryonic development, tissue homeostasis, and various physiological processes. Apart from the classical Wnt/β-catenin signaling pathway, there exist multiple non-classical Wnt signaling pathways, including the Wnt/PCP and Wnt/Ca2+ pathways. Non-coding RNAs (ncRNAs) are involved in the occurrence and development of PCa and the response to PCa treatment. ncRNAs are known to execute diverse regulatory roles in cellular processes, despite their inability to encode proteins. Among them, microRNAs, long non-coding RNAs, and circular RNAs play key roles in the regulation of the Wnt signaling pathway in PCa. Aberrant expression of these ncRNAs and dysregulation of the Wnt signaling pathway are one of the causes of cell proliferation, apoptosis, invasion, migration, and angiogenesis in PCa. Moreover, these ncRNAs affect the characteristics of PCa cells and hold promise as diagnostic and prognostic biomarkers. Herein, we summarize the role of ncRNAs in the regulation of the Wnt signaling pathway during the development of PCa. Additionally, we present an overview of the current progress in research on the correlation between these molecules and clinical features of the disease to provide novel insights and strategies for the treatment of PCa.

A novel co-culture model of human prostate epithelial and stromal cells for androgenic and antiandrogenic screening

The risk assessment of endocrine-disrupting chemicals (EDCs) greatly relies on in vitro screening. A 3-dimensional (3D) in vitro prostate model that can reflect physiologically-relevant prostate epithelial and stromal crosstalk can significantly advance the current androgen assessment. This study built a prostate epithelial and stromal co-culture microtissue model with BHPrE and BHPrS cells in scaffold-free hydrogels. The optimal 3D co-culture condition was defined, and responses of the microtissue to androgen (dihydrotestosterone, DHT) and anti-androgen (flutamide) exposure were characterized using molecular and image profiling techniques. The co-culture prostate microtissue maintained a stable structure for up to seven days and presented molecular and morphological features of the early developmental stage of the human prostate. The cytokeratin 5/6 (CK5/6) and cytokeratin 18 (CK18) immunohistochemical staining indicated epithelial heterogeneity and differentiation in these microtissues. The prostate-related gene expression profiling did not efficiently differentiate androgen and anti-androgen exposure. However, a cluster of distinctive 3D image features was identified and could be applied in the androgenic and anti-androgenic effect prediction. Overall, the current study established a co-culture prostate model that provided an alternative strategy for (anti-)androgenic EDC safety assessment and highlighted the potential and advantage of utilizing image features to predict endpoints in chemical screening.

Synthesis and Anticancer Activity of Novel Derivatives of α,β-Unsaturated Ketones Based on Oleanolic Acid: in Vitro and in Silico Studies against Prostate Cancer Cells

Herein, new derivatives of α,β-unsaturated ketones based on oleanolic acid (4 a-i) were designed, synthesized, characterized, and tested against human prostate cancer (PC3). According to the in vitro cytotoxic study, title compounds (4 a-i) showed significantly lower toxicity toward healthy cells (HUVEC) in comparison with the reference drug doxorubicin. The compounds with the lowest IC50 values on PC3 cell lines were 4 b (7.785 μM), 4 c (8.869 μM), and 4 e (8.765 μM). The results of the ADME calculations showed that the drug-likeness parameters were within the defined ranges according to Lipinski's and Jorgensen's rules. For the most potent compounds 4 b, 4 c, and 4 e, a molecular docking analysis using the induced fit docking (IFD) protocol was performed against three protein targets (PARP, PI3K, and mTOR). Based on the IFD scores, compound 4 b had the highest calculated affinity for PARP1, while compound 4 c had higher affinities for mTOR and PI3K. The MM-GBSA calculations showed that the most potent compounds had high binding affinities and formed stable complexes with the protein targets. Finally, a 50 ns molecular dynamics simulation was performed to study the behavior of protein target complexes under in silico physiological conditions.

A Pegylated Liposome Loaded with Raddeanin A for Prostate Cancer Therapy

Introduction

Raddeanin A (RA), a potent triterpenoid extracted from Anemone raddeana Regel, has a moderate therapeutic effect on prostate cancer (PCa), correlating with serious biological toxicity. Therefore, a RA-loaded PEGylated liposome drug delivery system was devised in this study.

Methods

Hydrogenated soybean phospholipids (HSPC), 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-Polyethyleneglycol-2000 (sodium salt) (DSPE-PEG2k), cholesterol (CHO), and RA were utilised to prepare a RA-loaded liposome (LRA) drug delivery system via the thin film hydration technique., The drug loading content was confirmed by high performance liquid chromatography. Dynamic light scattering was employed to evaluate the drug's particle size and stability. Methyl tetrazolium, colony formation, and Western blot (WB) were used in vitro to elucidate the inhibitory effect and mechanism of LRA on prostate cancer cells. Finally, xenograft model was used to confirm the tumor-inhibiting efficacy, clarify the mechanism, and determine the biosafety in mice.

Results

LRA has stable physicochemical properties and a diameter of 173.5 15.3 nm. LRA inhibited the growth of prostate cancer cells in a dose- and time-dependent manner. LRA can substantially reduce the expression of AR and HMGB1, induce apoptosis, regulate the expression of cell cycle-related proteins in vitro and in vivo. The results of the biosafety tests demonstrated that LRA effectively reduced the adverse effects of RA.

Conclusion

As a drug delivery system, LRA could effectively and safely inhibit the progression of prostate cancer.

Pro-tumorigenic role of lnc-ZNF30-3 as a sponge counteracting miR-145-5p in prostate cancer

BACKGROUND

Prostate cancer remains one of the deadliest neoplasms in developed countries. Identification of new molecular markers that predict the onset and progression of the disease could improve its clinical management. Low miR-145-5p expression is consistently found in primary tumors and metastases, but the regulatory mechanisms governing its functions remain largely unknown.

METHODS

Bioinformatics analysis was conducted to identify [1] a set of novel potential competing endogenous lncRNAs for sponging of miRNA-145-5p in prostate cancer and [2] miR-145-5p and other EMT-related miRNAs response elements in lnc-ZNF30-3. Quantification of miR-145-5p, lnc-ZNF30-3, and TWIST1 expression levels in tumor tissues in RNA sequencing datasets of our and TCGA PRAD cohorts revealed a correlation with clinical outcome of prostate cancer patients. Biochemical and cell biology approaches, such as RNA pull-down, western blot, immunostaining, and wound healing assays were used for evaluation of the impact of TWIST1/miR-145/ lnc-ZNF30-3 interactions in prostate cancer cells altered in miRNA and lncRNA expression.

RESULTS

We identified a few potential lncRNA sponges of miR-145-5p, including lnc-ZNF30-3. It contains five response elements for miR-145-5p, but also other miRNAs targeting EMT transcription factors. Lnc-ZNF30-3 is significantly upregulated in prostate cancer cell lines and tumor tissues, and its high expression is correlated with poor patient prognosis. We demonstrated that lnc-ZNF30-3 is associated with AGO2 and specifically interacts with the miR-145-5p seed region. Knockdown of lnc-ZNF30-3 results in decreased migration of prostate cancer cells and downregulation of EMT drivers such as TWIST1 and ZEB1 at both the RNA and protein levels. These phenotypic and molecular features of lnc-ZNF30-3-depleted cells are partially rescued by miR-145-5p inhibition.

CONCLUSIONS

Collectively, our results point to lnc-ZNF30-3 as a novel competing endogenous lncRNA for miR-145-5p and other miRNAs that target TWIST1 as well as other EMT transcription factors. Prostate cancer patients with high lncRNA expression in primary tumors show lower survival rate suggesting that lnc-ZNF30-3 may contribute to prostate cancer progression and metastasis.

Phosphorylation of nuclear receptors: Novelty and therapeutic implications

Nuclear receptors (NR) collectively regulate several biological functions in various organs. While NRs can be characterized by activation of the transcription of their signature genes, they also have other diverse roles. Although most NRs are directly activated by ligand binding, which induces cascades of events leading to gene transcription, some NRs are also phosphorylated. Despite extensive investigations, primarily focusing on unique phosphorylation of amino acid residues in different NRs, the role of phosphorylation in the biological activity of NRs in vivo has not been firmly established. Recent studies on the phosphorylation of conserved phosphorylation motifs within the DNA- and ligand-binding domains confirmed has indicated the physiologically relevance of NR phosphorylation. This review focuses on estrogen and androgen receptors, and highlights the concept of phosphorylation as a drug target.

The CDK7 inhibitor CT7001 (Samuraciclib) targets proliferation pathways to inhibit advanced prostate cancer

BACKGROUND

Current strategies to inhibit androgen receptor (AR) are circumvented in castration-resistant prostate cancer (CRPC). Cyclin-dependent kinase 7 (CDK7) promotes AR signalling, in addition to established roles in cell cycle and global transcription, providing a rationale for its therapeutic targeting in CRPC.

METHODS

The antitumour activity of CT7001, an orally bioavailable CDK7 inhibitor, was investigated across CRPC models in vitro and in xenograft models in vivo. Cell-based assays and transcriptomic analyses of treated xenografts were employed to investigate the mechanisms driving CT7001 activity, alone and in combination with the antiandrogen enzalutamide.

RESULTS

CT7001 selectively engages with CDK7 in prostate cancer cells, causing inhibition of proliferation and cell cycle arrest. Activation of p53, induction of apoptosis, and suppression of transcription mediated by full-length and constitutively active AR splice variants contribute to antitumour efficacy in vitro. Oral administration of CT7001 represses growth of CRPC xenografts and significantly augments growth inhibition achieved by enzalutamide. Transcriptome analyses of treated xenografts indicate cell cycle and AR inhibition as the mode of action of CT7001 in vivo.

CONCLUSIONS

This study supports CDK7 inhibition as a strategy to target deregulated cell proliferation and demonstrates CT7001 is a promising CRPC therapeutic, alone or in combination with AR-targeting compounds.

Revealing the Role of Alternariol in the Local Steroidogenesis in Human Prostate Normal and Cancer Cells

The mycotoxin alternariol (AOH) can be found in food products infected by Alternaria spp. and is considered an endocrine-disruptive mycotoxin. The main mechanism of AOH toxicity is associated with DNA damage and modulation of the inflammation process. Still, AOH is considered as one of the emerging mycotoxins. In this study, we have evaluated how AOH might affect the local steroidogenesis process in the prostate, in both normal and cancer cells. We have found that AOH itself modulates the cell cycle, inflammation, and apoptosis, rather than the steroidogenesis process in prostate cancer cells; however, in the presence of another steroidogenic agent, the influence on steroidogenesis is significant. Therefore, this is the first study to report the effect of AOH on local steroidogenesis in normal and prostate cancer cells. We postulate that AOH might modulate the release of the steroid hormones and expression of the key components by interfering with the steroidogenic pathway and might be considered a steroidogenesis-altering agent.

Imageological/Structural Study regarding the Improved Pharmacokinetics by 68Ga-Labeled PEGylated PSMA Multimer in Prostate Cancer

PMSA (prostate-specific membrane antigen) is currently the most significant target for diagnosing and treating PCa (prostate cancer). Herein, we reported a series ⁶⁸Ga/¹⁷⁷Lu-labeled multimer PSMA tracer conjugating with PEG chain, including [⁶⁸Ga]Ga-DOTA-(1P-PEG₄), [⁶⁸Ga]Ga-DOTA-(2P-PEG₀), [⁶⁸Ga]Ga-DOTA-(2P-PEG₄), and [⁶⁸Ga]Ga/[¹⁷⁷Lu]Lu-DOTA-(2P-PEG₄)₂, which showed an advantage of a multivalent effect and PEGylation to achieve higher tumor accumulation and faster kidney clearance. To figure out how structural optimizations based on a PSMA multimer and PEGylation influence the probe's tumor-targeting ability, biodistribution, and metabolism, we examined PSMA molecular probes' affinities to PC-3 PIP (PSMA-highly-expressed PC-3 cell line), and conducted pharmacokinetics analysis, biodistribution detection, small animal PET/CT, and SPECT/CT imaging. The results showed that PEG₄ and PSMA dimer optimizations enhanced the probes' tumor-targeting ability in PC-3 PIP tumor-bearing mice models. Compared with the PSMA monomer, the PEGylated PSMA dimer reduced the elimination half-life in the blood and increased uptake in the tumor, and the biodistribution results were consistent with PET/CT imaging results. [⁶⁸Ga]Ga-DOTA-(2P-PEG₄)₂ exhibited higher tumor-to-organ ratios. When labeled by lutetium-177, relatively high accumulation of DOTA-(2P-PEG₄)₂ was still detected in PC-3 PIP tumor-bearing mice models after 48 h, indicating its prolonged tumor retention time. Given the superiority in imaging, simple synthetic processes, and structural stability, DOTA-(2P-PEG₄)₂ is expected to be a promising tumor-targeting diagnostic molecular probe in future clinical practice.

Androgen Receptor Activation Induces Senescence in Thyroid Cancer Cells

Thyroid cancer (TC) is the most common endocrine malignancy, with an approximately three-fold higher incidence in women. TCGA data indicate that androgen receptor (AR) RNA is significantly downregulated in PTC. In this study, AR-expressing 8505C (anaplastic TC) (84E7) and K1 (papillary TC) cells experienced an 80% decrease in proliferation over 6 days of exposure to physiological levels of 5α-dihydrotestosterone (DHT). In 84E7, continuous AR activation resulted in G1 growth arrest, accompanied by a flattened, vacuolized cell morphology, with enlargement of the cell and the nuclear area, which is indicative of senescence; this was substantiated by an increase in senescence-associated β-galactosidase activity, total RNA and protein content, and reactive oxygen species. Additionally, the expression of tumor suppressor proteins p16, p21, and p27 was significantly increased. A non-inflammatory senescence-associated secretory profile was induced, significantly decreasing inflammatory cytokines and chemokines such as IL-6, IL-8, TNF, RANTES, and MCP-1; this is consistent with the lower incidence of thyroid inflammation and cancer in men. Migration increased six-fold, which is consistent with the clinical observation of increased lymph node metastasis in men. Proteolytic invasion potential was not significantly altered, which is consistent with unchanged MMP/TIMP expression. Our studies provide evidence that the induction of senescence is a novel function of AR activation in thyroid cancer cells, and may underlie the protective role of AR activation in the decreased incidence of TC in men.

In Vitro Pro-Apoptotic and Anti-Migratory Effects of Marantodes pumilum (syn. Labisia pumila) Extracts on Human Prostate Cancer Cell Lines: Bioguided Isolation of 5-Henicosene-1-yl-resorcinol

This study aims to evaluate the in vitro cytotoxic and anti-migratory effects of Marantodes pumilum Blume Kuntze plant extracts on prostate cancer cells, identify the active compound/s, and characterize their mechanism of action. The crude methanolic extract was partitioned into n-hexane (MPh), chloroform (MPc), and aqueous (MPa) extracts. Antiproliferative fractions (IC50 < 30 μg/mL based on SRB staining of LNCaP and PC3 cell lines) were further fractionated. Active compound/s were identified using spectroscopic methods. In vitro mechanistic studies on PC3 cells included: annexin V-FITC staining, mitochondrial membrane potential (MMP) depolarization measurements, the activity of caspases 3 and 7, nuclear DNA fragmentation, cell cycle analysis, modulation of Bax, Bcl-2, Smac/Diablo, Alox-5, VEGF-A, CXCR4, and CXCL12 mRNA gene expression via RT-PCR, 2D migration (scratch assay), and 3D invasion (Boyden chamber). MPc extract was the most active, inducing cell death (p < 0.05) via apoptosis, as evidenced by nuclear DNA fragmentation and an increase in MMP depolarization (p < 0.05) as well as the activation of caspases 3/7 (MPc p < 0.01) in both PC3 and LNCaP cell lines. In addition, MPc upregulated Bax and Smac/DIABLO, downregulated Bcl-2 (p < 0.05), and inhibited ALOX-5 mRNA gene expression (p < 0.001). MPc was not cytotoxic against normal human fibroblast cells (HDFa) at the tested concentrations. Moreover, MPc inhibited migration and invasion of PC3 cells (p < 0.01). These effects were accompanied by the downregulation of both VEGF-A and CXCL-12 gene expressions (p < 0.001). A monounsaturated 5-alkyl resorcinol was isolated as the active compound in the MPc extract and identified as 5-henicosene-1-yl-resorcinol.

In silico, in vitro and in vivo studies: Dibutyl phthalate promotes prostate cancer cell proliferation by activating Forkhead Box M1 and remission after Natura-α pretreatment

Dibutyl phthalate (DBP) is widely used in perfumes, cosmetics, shampoos and medical devices. It is ubiquitous in the environment and greatly endangers people's health. Several studies have reported that being exposed to it can promote the development of lung cancer, breast cancer, hepatoma, and multiple myeloma. However, there are still few studies on the specific molecular mechanism and prevention methods of DBP promoting the progression of prostate cancer. This study, in silico, in vitro and in vivo, aims to explore the promoting effect of DBP on prostate cancer cell proliferation. In silico analysis, we obtained a set of DBP interactive genes by utilizing TCGA, CTD and GEO database. These genes are mainly enriched in cell cycle regulatory pathways and they have high degree of homogeneity. We found that these genes shared one transcription factor - Forkhead Box M1 (FOXM1) by performing Chip-X Enrichment Analysis (Version 3.0). FOXM1, once called the 2010 Molecule of the Year, aberrantly expressed in up to 20 kinds of tumors. In vitro experiments, we used DBP at concentrations of 10^-8 M and 5 * 10^-7 M to treat C4-2 and PC3 cells for 6 days, respectively. Cell viability was promoted significantly. When Natura-α was added in the background of above-mentioned concentration of DBP, this effect was significantly inhibited. In addition, we also found that DBP can interfering with the efficacy of enzalutamide therapy. The introduction of Natura-α can also reverse this phenomenon. In vivo, subcutaneous tumor formation experiments in nude mice, 800 mg/kg/day DBP can promote the growth of prostate cancer. This phenomenon was suppressed when Natura-α (100 mg/kg/day) was added. Based on the results of the above three levels, we confirmed that DBP can target FOXM1 to promote prostate cancer cell proliferation. Natura-α can reverse its cancer-promoting effect. This study provides new insights into the impact of DBP on prostate cancer.

An integrated in vitro/in silico approach to assess the anti-androgenic potency of isobavachin

Isobavachin is a dietary flavanone with multiple biological activities. Our previous research has confirmed the estrogenicity of isobavachin, and this work aims to assess the anti-androgenic potency of isobavachin by an integrated in vitro and in silico approach. Isobavachin can limit the proliferation of prostate cancer cells by inducing a distinct G1 cell-cycle arrest. In addition, isobavachin also significantly represses the transcription of androgen receptor (AR)-downstream targets such as prostate specific antigen. Mechanistically, we demonstrated that isobavachin can disrupt the nuclear translocation of AR and promote its proteasomal degradation. The results of computer simulations showed that isobavachin can stably bind to AR, and the amino acid residue Gln711 may play a critical role in AR binding of both AR agonists and antagonists. In conclusion, this work has identified isobavachin as a novel AR antagonist.

Exploring pharmacological active ingredients of traditional Chinese medicine by pharmacotranscriptomic map in ITCM

With the emergence of high-throughput technologies, computational screening based on gene expression profiles has become one of the most effective methods for drug discovery. More importantly, profile-based approaches remarkably enhance novel drug-disease pair discovery without relying on drug- or disease-specific prior knowledge, which has been widely used in modern medicine. However, profile-based systematic screening of active ingredients of traditional Chinese medicine (TCM) has been scarcely performed due to inadequate pharmacotranscriptomic data. Here, we develop the largest-to-date online TCM active ingredients-based pharmacotranscriptomic platform integrated traditional Chinese medicine (ITCM) for the effective screening of active ingredients. First, we performed unified high-throughput experiments and constructed the largest data repository of 496 representative active ingredients, which was five times larger than the previous one built by our team. The transcriptome-based multi-scale analysis was also performed to elucidate their mechanism. Then, we developed six state-of-art signature search methods to screen active ingredients and determine the optimal signature size for all methods. Moreover, we integrated them into a screening strategy, TCM-Query, to identify the potential active ingredients for the special disease. In addition, we also comprehensively collected the TCM-related resource by literature mining. Finally, we applied ITCM to an active ingredient bavachinin, and two diseases, including prostate cancer and COVID-19, to demonstrate the power of drug discovery. ITCM was aimed to comprehensively explore the active ingredients of TCM and boost studies of pharmacological action and drug discovery. ITCM is available at http://itcm.biotcm.net.

Urolithin A analog inhibits castration-resistant prostate cancer by targeting the androgen receptor and its variant, androgen receptor-variant 7

We investigated the efficacy of a small molecule ASR-600, an analog of Urolithin A (Uro A), on blocking androgen receptor (AR) and its splice variant AR-variant 7 (AR-V7) signaling in castration-resistant prostate cancer (CRPC). ASR-600 effectively suppressed the growth of AR+ CRPC cells by inhibiting AR and AR-V7 expressions; no effect was seen in AR- CRPC and normal prostate epithelial cells. Biomolecular interaction assays revealed ASR-600 binds to the N-terminal domain of AR, which was further confirmed by immunoblot and subcellular localization studies. Molecular studies suggested that ASR-600 promotes the ubiquitination of AR and AR-V7 resulting in the inhibition of AR signaling. Microsomal and plasma stability studies suggest that ASR-600 is stable, and its oral administration inhibits tumor growth in CRPC xenografted castrated and non-castrated mice. In conclusion, our data suggest that ASR-600 enhances AR ubiquitination in both AR+ and AR-V7 CRPC cells and inhibits their growth in vitro and in vivo models.

Genetic profiling of hormone-sensitive and castration-resistant prostate cancers and identification of genetic mutations prone to castration-resistant prostate cancer

BACKGROUND

Genetic profiling of patients with prostate cancer could potentially identify mutations prone to castration-resistant prostate cancer (CRPC). Here, we aimed to identify the differences in genetic profiles of patients with hormone-sensitive prostate cancer (HSPC) and CRPC and stratify HSPC patients to identify mutations associated with CRPC progression.

METHODS

A total of 103 samples were collected, including 62 DNA samples from the tumor tissues of 59 HSPC patients and 41 cell-free DNA (cfDNA) samples from prostate cancer patients at different cancer stages. Targeted sequence was conducted on both the tissue DNA and cfDNA. The associations between mutations and clinical outcomes (CRPC-free time) were analyzed using χ2 test, logistic regression analysis, Kaplan-Meier analysis, and Cox regression analysis.

RESULTS

By comparing to that of cfDNA sequencing, the results from DNA sequencing of 1-needle (80%) and mixed 12-needle (77.8%) biopsies are highly comparable. FOXA1 (30.5%), CDK12 (23.7%), and TP53 (22.0%) were the top 3 most frequently mutated genes in HSPC patients; 50.8% (30/59) and 44.1% (26/59) HSPC patients had mutations in DDR and HRR pathway, respectively. Mutations in AR and APC as well as the members involved in the regulation of stem cell pluripotency and EMT pathway were often observed in CRPC samples. We established a panel of four genetic mutations (MSH2, CDK12, TP53, and RB1) to predict the risk of CRPC early progression with concordance index = 0.609 and the area under curve of the ROC curve as 0.838.

CONCLUSIONS

In this study, we demonstrated that the cfDNA can be used in genetic profiling in prostate cancer and our newly established panel is capable of predicting which mHSPC patient has a high risk of early CRPC progression.

Targeting the N-terminal domain of the androgen receptor: The effective approach in therapy of CRPC

The androgen receptor (AR) is dominant in prostate cancer (PCa) pathology. Current therapeutic agents for advanced PCa include androgen synthesis inhibitors and AR antagonists that bind to the hormone binding pocket (HBP) at the ligand binding domain (LBD). However, AR amplification, AR splice variants (AR-Vs) expression, and intra-tumoral de novo synthesis of androgens result in the reactivation of AR signalling. The AR N-terminal domain (NTD) plays an essential role in AR transcriptional activity. The AR inhibitor targeting NTD could potentially block the activation of both full-length AR and AR-Vs, thus overcoming major resistance mechanisms to current treatments. This review discusses the progress of research in various NTD inhibitors and provides new insight into the development of AR-NTD inhibitors.