Mechanisms of resistance in castration-resistant prostate cancer (CRPC)

From pituitary cells to prostate gland in health and disease: direct and indirect endocrine connections

The prostate gland is an endocrine-sensitive organ responding to multiple stimuli. Its development and function are regulated by multiple hormones (i.e. steroids such as androgens, estrogens and glucocorticoids) but also by other key hormonal systems such as those comprised by insulin-like growth factor 1 and insulin, which are sourced by different tissues [e.g. testicles/adrenal-gland/adipose-tissue/liver/pancreas, etc.). Particularly important for the endocrine control of prostatic pathophysiology and anatomy are hormones produced and/or secreted by different cell types of the pituitary gland [growth-hormone, luteinizing-hormone, follicle-stimulating hormone, and prolactin, oxytocin, arginine-vasopressin and melanocyte-stimulating hormone], which affect prostate gland function either directly or indirectly under physiological and pathophysiological conditions [e.g. metabolic dysregulation (e.g. obesity), and prostate transformations (e.g. prostate cancer)]. This review summarizes the impact of all pituitary hormone types on prostate gland under these diverse conditions including in vivo and in vitro studies.

Molecular pathways in reproductive cancers: a focus on prostate and ovarian cancer

Reproductive cancers, including prostate and ovarian cancer, are highly prevalent worldwide and pose significant health challenges. The molecular underpinnings of these cancers are complex and involve dysregulation of various cellular pathways. Understanding these pathways is crucial for developing effective therapeutic strategies. This review aims to provide an overview of the molecular pathways implicated in prostate and ovarian cancers, highlighting key genetic alterations, signaling cascades, and epigenetic modifications. A comprehensive literature search was conducted using databases such as PubMed, Web of Science, and Google Scholar. Articles focusing on molecular pathways in prostate and ovarian cancer were reviewed and analyzed. In prostate cancer, recurrent mutations in genes like AR, TP53, and PTEN drive tumor growth and progression. Androgen signaling plays a significant role, with alterations in the AR pathway contributing to resistance to antiandrogen therapies. In ovarian cancer, high-grade serous carcinomas are characterized by mutations in TP53, BRCA1/2, and homologous recombination repair genes. PI3K and MAPK pathways are frequently activated, promoting cell proliferation and survival. Epigenetic alterations, including DNA methylation and histone modifications, are also prevalent in both cancer types. The molecular pathways involved in prostate and ovarian cancer are diverse and complex. Targeting these pathways with precision medicine approaches holds promise for improving patient outcomes. Further research is needed to elucidate the mechanisms of resistance and identify novel therapeutic vulnerabilities.

Microbially produced imidazole propionate impairs prostate cancer progression through PDZK1

BACKGROUND

A close relationship exists between castration-resistant prostate cancer (CRPC) and histidine metabolism by gut microbes. However, the effects of the histidine metabolite imidazole propionate (IMP) on prostate cancer (PCa) and its underlying mechanisms are not well understood.

METHODS

We first assessed the effects of IMP on cell proliferation and migration at the cellular level. Subsequently, we investigated the mechanism of action of IMP using transcriptome sequencing, qPCR, and Western blot analysis. Finally, we validated our findings in vivo using a mouse model.

RESULTS

Histidine had no effect on PCa cell proliferation; however, IMP significantly inhibited the proliferation and migration of PC3 and DU145 cells. Mechanistic studies indicate that IMP exerts its effects by upregulating PDZK1 expression, which subsequently inhibits the phosphorylation of the PI3K-AKT pathway.

CONCLUSIONS

In conclusion, IMP significantly inhibits the progression of PCa, offering new insights into potential treatments for CRPC.

Prostate cancer epigenetics - from pathophysiology to clinical application

Prostate cancer is a multifactorial disease influenced by various molecular features. Over the past decades, epigenetics, which is the study of changes in gene expression without altering the DNA sequence, has been recognized as a major driver of this disease. In the past 50 years, advancements in technological tools to characterize the epigenome have highlighted crucial roles of epigenetic mechanisms throughout the entire spectrum of prostate cancer, from initiation to progression, including localized disease, metastatic dissemination, castration resistance and neuroendocrine transdifferentiation. Substantial advances in the understanding of epigenetic mechanisms in the pathophysiology of prostate cancer have been carried out, but translating preclinical achievements into clinical practice remains challenging. Ongoing research and biomarker-oriented clinical trials are expected to increase the likelihood of successfully integrating epigenetics into prostate cancer clinical management.

PlexinD1 is a driver and a therapeutic target in advanced prostate cancer

Aggressive prostate cancer (PCa) variants associated with androgen receptor signaling inhibitor (ARSI) resistance and metastasis remain poorly understood. Here, we identify the axon guidance semaphorin receptor PlexinD1 as a crucial driver of cancer aggressiveness in metastatic castration-resistant prostate cancer (CRPC). High PlexinD1 expression in human PCa is correlated with adverse clinical outcomes. PlexinD1 critically maintains CRPC aggressive behaviors in vitro and in vivo, and confers stemness and cellular plasticity to promote multilineage differentiation including a neuroendocrine-like phenotype for ARSI resistance. Mechanistically, PlexinD1 is upregulated upon relief of AR-mediated transcriptional repression of PlexinD1 under ARSI treatment, and subsdquently transactivates ErbB3 and cMet via direct interaction, which triggers the ERK/AKT pathways to induce noncanonical Gli1-dictated Hedgehog signaling, facilitating the growth and plasticity of PCa cells. Blockade of PlexinD1 by the protein inhibitor D1SP restricted CRPC growth in multiple preclinical models. Collectively, these findings characterize PlexinD1's contribution to PCa progression and offer a potential PlexinD1-targeted therapy for advanced PCa.

T-Cell redirecting bispecific antibodies: a review of a novel class of immuno-oncology for advanced prostate cancer

Novel T-cell immunotherapies such as bispecific T-cell engagers (BiTEs) are emerging as promising therapeutic strategies for prostate cancer. BiTEs are engineered bispecific antibodies containing two distinct binding domains that allow for concurrent binding to tumor-associated antigens (TAAs) as well as immune effector cells, thus promoting an immune response against cancer cells. Prostate cancer is rich in tumor associated antigens such as, but not limited to, PSMA, PSCA, hK2, and STEAP1 and there is strong biologic rationale for employment of T-cell redirecting BiTEs within the prostate cancer disease space. Early generation BiTE constructs employed in clinical study have demonstrated meaningful antitumor activity, but challenges related to drug delivery, immunogenicity, and treatment-associated adverse effects limited their success. The ongoing development of novel BiTE constructs continues to address these barriers and to yield promising results in terms of efficacy and safety. This review will highlight some of most recent developments of BiTE therapies for patients with advanced prostate cancer and the evolving data surrounding BiTE constructs undergoing clinical evaluation.

Adverse events in patients with castration-resistant prostate cancer treated with ra-223: a retrospective pharmacovigilance study

BACKGROUND

Radium-223 (Ra-223) received U.S. Food and Drug Administration (FDA) approval for treating castration-resistant prostate cancer with symptomatic bone metastases, excluding visceral metastases. Despite this, the safety profile of Ra-223 in large-scale, population-based use still needs to be explored.

RESEARCH DESIGN AND METHODS

This research assesses the side effects of Ra-223 by analyzing reports of adverse events (AEs) from the FDA's Adverse Event Reporting System (FAERS) database. Four sequential analysis strategies were employed to assess the significance of these AEs.

RESULTS

In total, 4,228 Ra-223-related AE reports were identified in the FAERS database. These Ra-223-induced AEs were observed in 26 target system organ classes (SOCs). 124 Ra-223-induced AEs were detected in 26 SOCs, predominantly affecting the blood and lymphatic systems. Other notable AEs included diarrhea, nausea, asthenia, fatigue, malaise, and decreased appetite, some of which were not previously documented in product specifications. The median time to onset of AEs was 56 days (Interquartile Range 26-103 days), with the majority of AEs occurring within the first three months after Ra-223 administration.

CONCLUSIONS

Our findings align with clinical observations and suggest potential new and unexpected AEs related to Ra-223, underscoring the need for prospective clinical studies to confirm these results and clarify their relationships. These insights provide valuable evidence for further safety studies and the rational use of Ra-223.

Future Prospect of Low-Molecular-Weight Prostate-Specific Membrane Antigen Radioisotopes Labeled as Theranostic Agents for Metastatic Castration-Resistant Prostate Cancer

Prostate cancer ranks as the fourth most common cancer among men, with approximately 1.47 million new cases reported annually. The emergence of prostate-specific membrane antigen (PSMA) as a critical biomarker has revolutionized the diagnosis and treatment of prostate cancer. Recent advancements in low-molecular-weight PSMA inhibitors, with their diverse chemical structures and binding properties, have opened new avenues for research and therapeutic applications in prostate cancer management. These novel agents exhibit enhanced tumor targeting and specificity due to their small size, facilitating rapid uptake and localization at the target site while minimizing the retention in non-target tissues. The primary aim of this study is to evaluate the potential of low-molecular-weight PSMA inhibitors labeled with radioisotopes as theranostic agents for prostate cancer. This includes assessing their efficacy in targeted imaging and therapy and understanding their pharmacokinetic properties and mechanisms of action. This study is a literature review focusing on in vitro and clinical research data. The in vitro studies utilize PSMA-targeted radioligands labeled with radioisotopes to assess their binding affinity, specificity, and internalization in prostate cancer cell lines. Additionally, the clinical studies evaluate the safety, effectiveness, and biodistribution of radiolabeled PSMA ligands in patients with advanced prostate cancer. The findings indicate promising outcomes regarding the safety and efficacy of PSMA-targeted radiopharmaceuticals in clinical settings. The specific accumulation of these agents in prostate tumor lesions suggests their potential for various applications, including imaging and therapy. This research underscores the promise of radiopharmaceuticals targeting PSMA in advancing the diagnosis and treatment of prostate cancer. These agents improve diagnostic accuracy and patients' outcomes by enhancing imaging capabilities and enabling personalized treatment strategies.

A TBX2-driven signaling switch from androgen receptor to glucocorticoid receptor confers therapeutic resistance in prostate cancer

Recent studies suggest that glucocorticoid receptor (GR) activation can cause enzalutamide resistance in advanced prostate cancer (PCa) via functional bypass of androgen receptor (AR) signaling. However, the specific molecular mechanism(s) driving this process remain unknown. We have previously reported that the transcription factor TBX2 is over-expressed in castrate-resistant prostate cancer (CRPC). In this study, using human PCa and CRPC cell line models, we demonstrate that TBX2 downregulates AR and upregulates GR through direct transcriptional regulation. TBX2 also activated the GR via TBX2-GR protein-protein interactions. Together, TBX2-driven repression of AR and activation of GR resulted in enzalutamide resistance. Our laboratory findings are supported by clinical samples, which show a similar and consistent pattern of transcriptional activity among TBX2, AR and GR across patient cohorts. Notably, we report that SP2509, an allosteric inhibitor of the demethylase-independent function of LSD1 (a TBX2-interacting protein in the COREST complex) disrupts both TBX2-LSD1 and TBX2-GR protein-protein interactions, revealing a unique mode of SP2509 action in CRPC. Taken together, our study identifies the TBX2-driven AR- to GR- signaling switch as a molecular mechanism underlying enzalutamide resistance and provides key insights into a potential therapeutic approach for targeting this switch by disrupting TBX2-GR and TBX2-LSD1 protein-protein interactions.

Highly efficient nucleic acid encapsulation method for targeted gene therapy using antibody conjugation system

Gene therapy has surfaced as a promising avenue for treating cancers, offering the advantage of deliberate adjustment of targeted genes. Nonetheless, the swift degradation of nucleic acids in the bloodstream necessitates an effective and secure delivery system. The widespread utilization of poly(lactic-co-glycolic acid) (PLGA) nanoparticles as drug delivery systems has highlighted challenges in controlling particle size and release properties. Moreover, the encapsulation of nucleic acids exacerbates these difficulties due to the negatively charged surface of PLGA nanoparticles. In this study, we aimed to improve the encapsulation efficiency of nucleic acids by employing negatively charged microbeads and optimizing the timing of the specific formulation steps. Furthermore, by conjugating PSMA-617, a ligand for the prostate-specific membrane antigen (PSMA), with PLGA nanoparticles, we assessed the antitumor effects and the efficacy of a nucleic acid delivery system on a prostate cancer model. The employed technique within the nucleic acid encapsulation system represents a novel approach that could be adapted to encapsulate various kinds of nucleic acids. Moreover, it enables the attachment of targeting moieties to different cell membrane proteins, thereby unveiling new prospects for precise therapeutics in cancer therapy.

Defining Splicing Factor Requirements for Androgen Receptor Variant Synthesis in Advanced Prostate Cancer

Resistance to androgen receptor (AR)-targeted therapies represents a major challenge in prostate cancer. A key mechanism of treatment resistance in patients who progress to castration-resistant prostate cancer (CRPC) is the generation of alternatively spliced AR variants (AR-V). Unlike full-length AR isoforms, AR-Vs are constitutively active and refractory to current receptor-targeting agents and hence drive tumor progression. Identifying regulators of AR-V synthesis may therefore provide new therapeutic opportunities in combination with conventional AR-targeting agents. Our understanding of AR transcript splicing, and the factors that control the synthesis of AR-Vs, remains limited. Although candidate-based approaches have identified a small number of AR-V splicing regulators, an unbiased analysis of splicing factors important for AR-V generation is required to fill an important knowledge gap and furnish the field with novel and tractable targets for prostate cancer treatment. To that end, we conducted a bespoke CRISPR screen to profile splicing factor requirements for AR-V synthesis. MFAP1 and CWC22 were shown to be required for the generation of AR-V mRNA transcripts, and their depletion resulted in reduced AR-V protein abundance and cell proliferation in several CRPC models. Global transcriptomic analysis of MFAP1-depleted cells revealed both AR-dependent and -independent transcriptional impacts, including genes associated with DNA damage response. As such, MFAP1 downregulation sensitized prostate cancer cells to ionizing radiation, suggesting that therapeutically targeting AR-V splicing could provide novel cellular vulnerabilities which can be exploited in CRPC. Implications: We have utilized a CRISPR screening approach to identify key regulators of pathogenic AR splicing in prostate cancer.

Chromatin accessibility is associated with therapeutic response in prostate cancer

Treatment of advanced prostate cancer is challenging due to a lack of effective therapies. Therefore, it is important to understand the molecular mechanisms underlying therapeutic resistance in prostate cancer and to identify promising drug targets offering significant clinical advantages. Given the pivotal role of dysregulated transcriptional programs in the therapeutic response, it is essential to prioritize translational efforts targeting cancer-associated transcription factors (TFs). The present study investigated whether chromatin accessibility was associated with therapeutic resistance in prostate cancer using Assay for Transposase-Accessible Chromatin with sequencing (ATAC-seq) data. The bioinformatics analysis identified differences in chromatin accessibility between the drug response (Remission) and drug resistance (Disease) groups. Additionally, a significant association was observed between chromatin accessibility, transcriptional output and TF activity. Among TFs, forkhead box protein M1 (FOXM1) was identified as a TF with high activity and expression in the Disease group. Notably, the results of the computational analysis were validated by FOXM1 knockdown experiments, which resulted in suppressed cell proliferation and enhanced therapeutic sensitivity in prostate cancer cells. The present findings demonstrated that chromatin accessibility and TF activity may be associated with therapeutic resistance in prostate cancer. Additionally, these results provide the basis for future investigations aimed at understanding the molecular mechanisms of drug resistance and developing novel therapeutic approaches for prostate cancer.

Changes in the gut microbial profile during long-term androgen deprivation therapy for prostate cancer

BACKGROUND

Recent studies have highlighted the association between androgen deprivation therapy (ADT) and the gut microbiota in prostate cancer. However, the impact of long-term ADT remains to be explored.

METHODS

To examine changes in the gut microbial profile from short-term (a median of 7 months), and middle-term (a median of 18 months) to long-term ADT (>33 months), 16S rRNA data from 56 fecal samples were reanalyzed. Additionally, a two-sample Mendelian randomization was employed to investigate the relationships between particular microbial signatures and prostate cancer as well as testosterone levels.

RESULTS

In contrast to the short- and middle-term ADT groups, the long-term ADT group had significant changes in alpha and beta diversity. In particular, the relative abundance of genera such as Catenibacterium and Holdemanella decreased in the long-term ADT group, whereas the opportunistic bacterium (Erysipelatoclostridium) and Ruminococcus gnavus showed increased abundance over ADT time. Moreover, a two-sample Mendelian randomization analysis revealed the negative associations between genetically predicated genera Coprobacter, Ruminococcaceae UCG002/011, and Defluviitaleacea-UCG-011, and testosterone levels.

CONCLUSIONS

In conclusion, long-term ADT use in prostate cancer patients was associated with detrimental changes in gut microbiota, including an increase in genera related to testosterone synthesis and opportunistic bacteria. These changes may be related to disease progression and side effects of long-term ADT while further longitudinal studies are required to prove this relationship.

Major adverse cardiovascular events of enzalutamide versus abiraterone in prostate cancer: a retrospective cohort study

BACKGROUND

While the cardiovascular risks of androgen receptor pathway inhibitors have been studied, they were seldom compared directly. This study compares the risks of major adverse cardiovascular events (MACE) between enzalutamide and abiraterone among prostate cancer (PCa) patients.

METHODS

Adult PCa patients receiving either enzalutamide or abiraterone in addition to androgen deprivation therapy in Hong Kong between 1 December 1999 and 31 March 2021 were identified in this retrospective cohort study. Patients who switched between enzalutamide and abiraterone, initiated abiraterone used without steroids, or experienced prior cardiac events were excluded. Patients were followed-up until 30 September 2021. The primary outcomes were MACE, a composite of stroke, myocardial infarction (MI), Heart failure (HF), or all-cause mortality and a composite of adverse cardiovascular events (CACE) not including all-cause mortality. The secondary outcomes were individual components of MACE. Inverse probability treatment weighting was used to balance covariates between treatment groups.

RESULTS

In total, 1015 patients were analyzed (456 enzalutamide users and 559 abiraterone users; mean age 70.6 ± 8.8 years old) over a median follow-up duration of 11.3 (IQR: 5.3-21.3) months. Enzalutamide users had significantly lower risks of 4P-MACE (weighted hazard ratio (wHR) 0.71 [95% confidence interval (CI) 0.59-0.86], p < 0.001) and CACE (wHR 0.63 [95% CI: 0.42-0.96], p = 0.031), which remained consistent in multivariable analysis. Such an association may be stronger in patients aged ≥65 years or without diabetes mellitus and was independent of bilateral orchidectomy. Enzalutamide users also had significantly lower risks of MI (wHR 0.57 [95% CI: 0.33-0.97], p = 0.040) and all-cause mortality (wHR 0.71 [95% CI: 0.59-0.85], p < 0.001).

CONCLUSION

Enzalutamide was associated with lower cardiovascular risks than abiraterone in PCa patients.

IL-17RA/CTSK axis mediates H. pylori-induced castration-resistant prostate cancer growth

In this investigation, we explored the molecular dynamics guiding the progression of castration-resistant prostate cancer (CRPC) influenced by Helicobacter pylori (H. pylori)-mediated M2 polarization of macrophages through the IL-17RA/CTSK/EMT axis. An 830-patient clinical trial categorized subjects into hormone-sensitive prostate cancer (HSPC) and CRPC groups. H. pylori infection, evaluated by ELISA, exhibited a higher incidence in CRPC patients, impacting overall survival (OS) and progression-free survival. In-depth in vitro and in vivo experiments, including 16S rDNA sequencing, immunohistochemical tests, and transcriptome analysis, unveiled that H. pylori promotes CRPC growth and metastasis by upregulating IL-17RA and CTSK, leading to enhanced EMT. Notably, M2 macrophages emerged as pivotal immune cells influencing CRPC progression. This study uncovers a novel pathway wherein H. pylori enrichment exacerbates CRPC by inducing macrophage M2 polarization, IL-17RA/CTSK expression, and EMT activation, shedding light on a previously unrecognized mechanism contributing to the growth and metastasis of CRPC.

PINK1-Mediated Mitochondrial Activity Confers Olaparib Resistance in Prostate Cancer Cells

SIGNIFICANCE

Olaparib, a PARP inhibitor, is effective against various cancers, including prostate cancer. However, resistance to olaparib poses a significant challenge. This study uncovers that mitochondrial alterations and PINK1 gene overexpression contribute to this resistance in prostate cancer cells. Enhanced mitochondrial functionality and increased PINK1 expression in olaparib-resistant cells underscore the importance of targeting mitochondrial dynamics and PINK1 to develop more effective treatments for overcoming olaparib resistance in prostate cancer.

Iroquois homeobox 4 (IRX4) derived micropeptide promotes prostate cancer progression and chemoresistance through Wnt signalling dysregulation

BACKGROUND

Prostate cancer (PCa) is a commonly diagnosed cancer. Genome-wide association studies have implicated Iroquois homeobox 4 (IRX4) in PCa susceptibility, yet its functional roles remain unclear. We discovered a 78-amino acid micropeptide (miPEP, IRX4_PEP1), encoded from the alternative start site within the IRX4 gene. The miPEPs, encoded through short open reading frames (sORFs) have emerged as regulators of diverse biological processes. However, the significance of miPEPs in prostate tumorigenesis and therapy response remains unexplored to date. Here, we demonstrated the unique role of IRX4_PEP1 in PCa.

METHODS

The role of IRX4_PEP1 was evaluated in PCa in vitro via functional assays and comprehensive pathway analysis. The interacting partners of IRX4_PEP1 were identified using an immunoprecipitation assay, and the impact of IRX4_PEP1 on PCa stem cells was assessed through a stem cell enrichment assay. Additionally, the expression of IRX4_PEP1 was evaluated in PCa patient samples for its potential diagnostic and prognostic significance.

RESULTS

Here we show IRX4_PEP1 promotes PCa cell proliferation, migration, and invasion by interacting with heterogeneous nuclear ribonucleoprotein K (HNRPK). Notably, IRX4_PEP1 dysregulates Wnt signalling by interacting with Catenin beta 1 (β catenin; CTNB1), elevating PCa stemness markers, and fostering docetaxel resistance. Clinically, IRX4_PEP1 expression is elevated in PCa tissues and correlates positively with disease aggressiveness. CTNNB1, HNRNPK levels, and ssGSEA enrichment score of WNT/CTNB1 signalling correlate positively with IRX4_PEP1 in PCa tissues.

CONCLUSIONS

These findings highlight IRX4_PEP1 role in PCa stemness and chemoresistance, suggesting it as a therapeutic target and potential diagnostic marker.

Long non-coding RNAs: regulators of autophagy and potential biomarkers in therapy resistance and urological cancers

The non-coding RNAs (ncRNAs) comprise a large part of human genome that mainly do not code for proteins. Although ncRNAs were first believed to be non-functional, the more investigations highlighted tthe possibility of ncRNAs in controlling vital biological processes. The length of long non-coding RNAs (lncRNAs) exceeds 200 nucleotidesand can be present in nucleus and cytoplasm. LncRNAs do not translate to proteins and they have been implicated in the regulation of tumorigenesis. On the other hand, One way cells die is by a process called autophagy, which breaks down proteins and other components in the cytoplasm., while the aberrant activation of autophagy allegedly involved in the pathogenesis of diseases. The autophagy exerts anti-cancer activity in pre-cancerous lesions, while it has oncogenic function in advanced stages of cancers. The current overview focuses on the connection between lncRNAs and autophagy in urological cancers is discussed. Notably, one possible role for lncRNAs is as diagnostic and prognostic variablesin urological cancers. The proliferation, metastasis, apoptosis and therapy response in prostate, bladder and renal cancers are regulated by lncRNAs. The changes in autophagy levels can also influence the apoptosis, proliferation and therapy response in urological tumors. Since lncRNAs have modulatory functions, they can affect autophagy mechanism to determine progression of urological cancers.

Clinico-Pathological Factors and AR-LBD Mutations in Early and Late Castration-Resistant Prostate Cancer

Background

Prostate cancer (PCa) is not well understood because of its enormous biological heterogeneity and unreliable progression. We conducted this retrospective analysis to examine the variables predicting early and late progression to castration-resistant PCa (CRPC) for better management of this disease.

Methods

This single institutional retrospective study was conducted from January 2018 to January 2022. A total of 98 consecutive men meeting with the diagnosis of CRPC as per the inclusion criteria were included in the study and were stratified in four quartiles on the basis of time to CRPC (time to castration resistance [TTCR]) development. Early CRPC (1st quartile, TTCR = 6-12 months) and late CRPC (4th quartile, TTCR = 38-120 months) were then compared on the basis of different clinical, pathological and AR-LBD sequence to find the correlation with response duration.

Results

Median time to develop castration resistance was 25 ± 26.44 months. The mean age of the patients was 66.8 ± 9.20 years and median baseline PSA was calculated 100±685.06 ng/mL respectively. Higher Gleason score (≥7-10) was found to be significantly associated with early development of CRPC (p<0.001) and lower nadir PSA was significantly indicating late CRPC progression (p<0.005). No mutations were found in androgen receptor exon-5, 6, 7 except a homozygous mutation in the 7th intronic region, which is involved in splice variants formation playing noteworthy role in CRPC development.

Conclusion

Time for metastatic PCa to CRPC ranges from 6-120 months revealing its heterogeneous nature. Early age presentation in the clinic and high initial PSA and high grade (GS>7) at diagnosis were positively associated with early CRPC while lower nadir PSA was correlated with late CRPC progression. No remarkable genomic mutations were discovered. Therefore, more data are needed and further research is required with large no. of patients to discover the predictive prognostic biomarkers for better patients' management.

AR expression-independent XRCC3 mediates DNA damage-induced p53/Bax signaling pathway activation against prostate cancer

BACKGROUND

Androgen deprivation therapy (ADT) resistance is closely associated with altered AR status. Aberrant AR expression is critical for the induction of ADT resistance, necessitating the identification of an anti-PCa target independent of AR expression.

METHODS

Transcriptomic data and clinical information of PRAD were obtained from TCGA database. Genes with PCa-related and AR expression-independent were screened by bioinformatics, and characterized by PPI and GO functional enrichment analyses. Candidate genes were locked by co-expression correlation and disease-free survival (DFS) analyses. A prognostic gene set was established using LASSO Cox regression algorithm. Cox proportional risk regression was performed to identify a key prognostic gene. Expression of the target protein in PCa tissues was verified by The Human Protein Atlas database. In vitro validation of cellular function and molecular mechanism by knockdown and overexpression of the target gene.

RESULTS

Two AR expression-independent genes (SLC43A1 and XRCC3) were available for the optimal prognostic model. This gene set effectively predicted PRAD patients' DFS at 1-, 3- and 5-year, where XRCC3 and tumor (T) stage were independent risk factors. XRCC3 was higher expressed in PRAD patients with T3-T4 stages and accompanied by poorer DFS. IHC staining also validated its higher expression in high-risk PCa tissues. In vitro experiments demonstrated that silencing XRCC3 significantly inhibited 22Rv1 and DU145 cell proliferation, migration and invasion, while promoted apoptosis. Further, silencing XRCC3 promoted DNA damage-induced p53/Bax signaling pathway activation, which was absent with overexpression.

CONCLUSION

Silencing XRCC3 exerts anti-PCa effects by promoting DNA damage-induced p53/Bax signaling pathway activation in an AR expression-independent manner.

NRG1 secreted by cancer-associated fibroblasts contributes to enzalutamide resistance in prostate cancer cells

While androgen deprivation therapy (ADT) continues to be a fundamental aspect of prostate cancer treatment, the development of castration-resistant prostate cancer (CRPC) emphasizes the necessity for a more profound understanding of the tumor microenvironment (TME). Normal fibroblasts (NFs) and cancer-associated fibroblasts (CAFs) were isolated and characterized from normal control and prostate cancer specimens, respectively. PC3 and DU145 cells, and the corresponding enzalutamide resistant counterparts, PC3-EnzR and DU145-EnzR, were co-cultured with NFs or CAFs to evaluate the effects of TME in driving enzalutamide resistance. Cell viability of prostate cancer cells was examined by MTT assay. The study also utilized recombinant human neuregulin-1 (NRG1) protein and siRNA to modulate NRG1 expression in CAFs. RT-qPCR, Western blot, and ELISA were employed to assess gene and protein expressions related to the NRG1-HER3 signaling pathway and its association with enzalutamide resistance. CAFs significantly promoted cell growth and enzalutamide resistance of PC3-EnzR and DU145-EnzR cells through substantial increased secretion of NRG1 by CAFs. Co-culturing enzalutamide-resistant prostate cancer cells (PC3-EnzR and DU145-EnzR) with CAFs further enhanced enzalutamide resistance, as evidenced by elevated IC50 values. Inhibition of NRG1 in CAFs attenuated their impact on enzalutamide resistance, providing insight into the role of NRG1 in mediating the crosstalk between CAFs and prostate cancer in the context of enzalutamide resistance. This study elucidates the pivotal role of CAF-secreted NRG1 in promoting enzalutamide resistance in prostate cancer, providing valuable insights for developing targeted therapeutic strategies to overcome resistance in advanced prostate cancer.

GOLM1 promotes prostate cancer progression via interaction with PSMD1 and enhancing AR-driven transcriptional activation

Aberrant transcriptional activation of the androgen receptor (AR) is a predominant cause of prostate cancer (PCa), including both in the initial and androgen-independent stages. Our study highlights Golgi membrane protein 1 (GOLM1) as a key regulator of AR-driven transcriptional activity in PCa progression. Utilizing local clinical data and TCGA data, we have established a robust association between GOLM1 and AR target genes, and further demonstrated that GOLM1 can enhance the expression of AR target genes. We discovered that GOLM1 interacts with PSMD1, a component of the 19S regulatory complex in the 26S proteasome, using mass spectrometry and Co-IP analysis. It is well known that ubiquitin-proteasome plays a vital role in AR expression and transcriptional regulation. Our findings demonstrate that GOLM1 enhances ubiquitin proteasome activity by binding to PSMD1, thereby facilitating AR-driven transcriptional activity and PCa progression. These results indicate that GOLM1 and its associated proteins may become potential therapeutic targets for PCa characterized by dysregulated AR-driven transcriptional activation.

Prostate Cancer: A Review of Genetics, Current Biomarkers and Personalised Treatments

BACKGROUND

Prostate cancer is the second leading cause of cancer deaths in men, second only to lung cancer. Despite this, diagnosis and prognosis methods remain limited, with effective treatments being few and far between. Traditionally, prostate cancer is initially tested for through a prostate serum antigen (PSA) test and a digital rectum examination (DRE), followed by confirmation through an invasive prostate biopsy. The DRE and biopsy are uncomfortable for the patient, so less invasive, accurate diagnostic tools are needed. Current diagnostic tools, along with genes that hold possible biomarker uses in diagnosis, prognosis and indications for personalised treatment plans, were reviewed in this article.

RECENT FINDINGS

Several genes from multiple families have been identified as possible biomarkers for disease, including those from the MYC and ETS families, as well as several tumour suppressor genes, Androgen Receptor signalling genes and DNA repair genes. There have also been advances in diagnostic tools, including MRI-targeted and liquid biopsies. Several personalised treatments have been developed over the years, including those that target metabolism-driven prostate cancer or those that target inflammation-driven cancer.

CONCLUSION

Several advances have been made in prostate cancer diagnosis and treatment, but the disease still grows year by year, leading to more and more deaths annually. This calls for even more research into this disease, allowing for better diagnosis and treatment methods and a better chance of patient survival.

Identification of blood lipid markers of docetaxel treatment in prostate cancer patients

Docetaxel is commonly used for treatment of castration-resistant prostate cancer. Unfortunately, many prostate cancer patients develop resistance to docetaxel. Clinical markers less invasive than biopsies, such as blood samples, would be ideal for monitoring and predicting patient treatment outcomes to docetaxel. Lipid alterations are often associated with the progression of many cancers, including prostate cancer. This study investigated the use of lipids from whole blood as clinical markers for docetaxel resistance in a small cohort of patients with prostate cancer. Qualitative lipidomics was performed by liquid chromatography-tandem mass spectrometry to assess the lipid composition of prostate cancer cells exposed to docetaxel as well as whole blood from prostate cancer patients before, during and after docetaxel treatment. Three patients had castration resistant prostate cancer, three had castration sensitive prostate cancer, and four had de novo prostate cancer during the extent of the study. Mean decrease accuracy and classical univariate receiving operating characteristic curve analyses were performed to identify potential biomarkers. In total, 245 and 221 altered lipids were identified from a second stage of mass spectrometry analysis of prostate cancer cells and clinical blood samples, respectively. Both models indicated that docetaxel treatment altered ether-linked phosphatidylcholines, lysophosphatidylcholine, diacylglycerols, ceramides, hexosylceramides, and sphingomyelins. The results also indicated several lipid changes were associated with sphingolipid signaling and metabolism, and glycerophospholipid metabolism. Collectively, these data suggest the potential usage of identified lipid species as indicators of docetaxel resistance in prostate cancer.

Navigating the landscape of theranostics in nuclear medicine: current practice and future prospects

Theranostics refers to the combination of diagnostic biomarkers with therapeutic agents that share a specific target expressed by diseased cells and tissues. Nuclear medicine is an exciting component explored for its applicability in theranostic concepts in clinical and research investigations. Nuclear theranostics is based on the employment of radioactive compounds delivering ionizing radiation to diagnose and manage certain diseases employing binding with specifically expressed targets. In the realm of personalized medicine, nuclear theranostics stands as a beacon of potential, potentially revolutionizing disease management. Studies exploring the theranostic profile of radioactive compounds have been presented in this review along with a detailed explanation of radioactive compounds and their theranostic applicability in several diseases. It furnishes insights into their applicability across diverse diseases, elucidating the intricate interplay between these compounds and disease pathologies. Light is shed on the important milestones of nuclear theranostics beginning with radioiodine therapy in thyroid carcinomas, MIBG labelled with iodine in neuroblastoma, and several others. Our perspectives have been put forth regarding the most important theranostic agents along with emerging trends and prospects.

Lipid Metabolism Modulatory Cisplatin Prodrug Sensitizes Resistant Prostate Cancer toward Androgen Deprivation Therapy

Mainstream treatment modalities which dominate the therapeutic landscape of prostate cancer (PCa) are prostatectomy, radiation therapy, and androgen deprivation therapy (ADT) or castration. These therapeutic options can extend the life expectancy of the patients but eventually fail to completely cure the disease. Despite undergoing ADT, patients still experience disease recurrence. One of the reasons for this recurrence is the binding of the basal androgens present in blood plasma to the androgen receptor (AR). At this stage, the disease becomes castration-resistant prostate cancer (CRPC) showing resistance to ADT promoting progression, and there is no effective treatment available. Although another male cancer such as testicular cancer responds to cisplatin-based therapy very well, PCa is resistant to cisplatin. In our continued effort to find the pathways that are important for such resistance, we link in this report, tumor metabolism driven androgen regulation and PCa resistance toward cisplatin-based therapy. To delve deeper into understanding how metabolic modulatory cisplatin prodrugs can be used to target the ADT resistant population, we demonstrate that metabolic inhibition by a cisplatin prodrug, Platin-L has the potential to modulate AR activity and resensitize ADT resistant cells toward cisplatin-based chemotherapy as well as ADT. The mode of action for Platin-L is inhibition of fatty acid oxidation (FAO) of prostate cancer cells. We demonstrated that FAO inhibition by Platin-L in PCa cells contribute to AR regulation resulting in altered tumorigenicity of androgen sensitive prostate cancer.

Combination of PARP Inhibitors and Androgen Receptor Pathway Inhibitors in Metastatic Castration-Resistant Prostate Cancer

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

Computational drug discovery pipelines identify NAMPT as a therapeutic target in neuroendocrine prostate cancer

Neuroendocrine prostate cancer (NEPC) is an aggressive advanced subtype of prostate cancer that exhibits poor prognosis and broad resistance to therapies. Currently, few treatment options are available, highlighting a need for new therapeutics to help curb the high mortality rates of this disease. We designed a comprehensive drug discovery pipeline that quickly generates drug candidates ready to be tested. Our method estimated patient response to various therapeutics in three independent prostate cancer patient cohorts and selected robust candidate drugs showing high predicted potency in NEPC tumors. Using this pipeline, we nominated NAMPT as a molecular target to effectively treat NEPC tumors. Our in vitro experiments validated the efficacy of NAMPT inhibitors in NEPC cells. Compared with adenocarcinoma LNCaP cells, NAMPT inhibitors induced significantly higher growth inhibition in the NEPC cell line model NCI-H660. Moreover, to further assist clinical development, we implemented a causal feature selection method to detect biomarkers indicative of sensitivity to NAMPT inhibitors. Gene expression modifications of selected biomarkers resulted in changes in sensitivity to NAMPT inhibitors consistent with expectations in NEPC cells. Validation of these markers in an independent prostate cancer patient dataset supported their use to inform clinical efficacy. Our findings pave the way for new treatments to combat pervasive drug resistance and reduce mortality. Furthermore, this research highlights the use of drug sensitivity-related biomarkers to understand mechanisms and potentially indicate clinical efficacy.

The polyunsaturated fatty acid docosahexaenoic affects mitochondrial function in prostate cancer cells

BACKGROUND

Prostate cancer (PCa) shows a rewired metabolism featuring increased fatty acid uptake and synthesis via de novo lipogenesis, both sharply related to mitochondrial physiology. The docosahexaenoic acid (DHA) is an omega-3 polyunsaturated fatty acid (PUFA) that exerts its antitumoral properties via different mechanisms, but its specific action on mitochondria in PCa is not clear. Therefore, we investigated whether the DHA modulates mitochondrial function in PCa cell lines.

METHODS

Here, we evaluated mitochondrial function of non-malignant PNT1A and the castration-resistant (CRPC) prostate 22Rv1 and PC3 cell lines in response to DHA incubation. For this purpose, we used Seahorse extracellular flux assay to assess mitochondria function, [14C]-glucose to evaluate its oxidation as well as its contribution to fatty acid synthesis, 1H-NMR for metabolite profile determination, MitoSOX for superoxide anion production, JC-1 for mitochondrial membrane polarization, mass spectrometry for determination of phosphatidylglycerol levels and composition, staining with MitoTracker dye to assess mitochondrial morphology under super-resolution in addition to Transmission Electron Microscopy, In-Cell ELISA for COX-I and SDH-A protein expression and flow cytometry (Annexin V and 7-AAD) for cell death estimation.

RESULTS

In all cell lines DHA decreased basal respiratory activity, ATP production, and the spare capacity in mitochondria. Also, the omega-3 induced mitochondrial hyperpolarization, ROS overproduction and changes in membrane phosphatidylglycerol composition. In PNT1A, DHA led to mitochondrial fragmentation and it increased glycolysis while in cancer cells it stimulated glucose oxidation, but decreased de novo lipogenesis specifically in 22Rv1, indicating a metabolic shift. In all cell lines, DHA modulated several metabolites related to energy metabolism and it was incorporated in phosphatidylglycerol, a precursor of cardiolipin, increasing the unsaturation index in the mitochondrial membrane. Accordingly, DHA triggered cell death mainly in PNT1A and 22Rv1.

CONCLUSION

In conclusion, mitochondrial metabolism is significantly affected by the PUFA supplementation to the point that cells are not able to proliferate or survive under DHA-enriched condition. Moreover, combination of DHA supplementation with inhibition of metabolism-related pathways, such as de novo lipogenesis, may be synergistic in castration-resistant prostate cancer.

GATA2 promotes castration-resistant prostate cancer development by suppressing IFN-β axis-mediated antitumor immunity

Castration-resistant prostate cancer (CRPC) nearly inevitably develops after long-term treatment with androgen deprivation therapy (ADT), leading to significant mortality. Investigating the mechanisms driving CRPC development is imperative. Here, we determined that the pioneer transcription factor GATA2, which is frequently amplified in CRPC patients, inhibits interferon (IFN)-β-mediated antitumor immunity, thereby promoting CRPC progression. Employing a genetically engineered mouse model (GEMM), we demonstrated that GATA2 overexpression hindered castration-induced cell apoptosis and tumor shrinkage, facilitating tumor metastasis and CRPC development. Notably, GATA2 drives castration resistance predominantly via repressing castration-induced activation of IFN-β signaling and CD8+ T-cell infiltration. This finding aligns with the negative correlation between GATA2 expression and IFNB1 expression, as well as CD8+ T-cell infiltration in CRPC patients. Mechanistically, GATA2 recruited PIAS1 as corepressor, and reprogramed the cistrome of IRF3, a key transcription factor of the IFN-β axis, in an androgen-independent manner. Furthermore, we identified a novel silencer element that facilitated the function of GATA2 and PIAS1 through looping to the IFNB1 promoter. Importantly, depletion of GATA2 augmented antitumor immunity and attenuated CRPC development. Consequently, our findings elucidate a novel mechanism wherein GATA2 promotes CRPC progression by suppressing IFN-β axis-mediated antitumor immunity, underscoring GATA2 as a promising therapeutic target for CRPC.

Investigating miR-6880-5p in extracellular vesicle from plasma as a prognostic biomarker in endocrine therapy-treated castration-resistant prostate cancer

BACKGROUND

Advancements in the diagnosis, treatment, and surveillance of castration-resistant prostate cancer (CRPC) have progressed considerably, but a new biomarker that combines existing clinical and pathological data could be useful for a more precise diagnosis and prognosis. Some investigations have found that extracellular vesicle (EV)-derived miRNAs play crucial roles in various types of malignant tumors. The objective of this study was to explore EV miRNA and identify its biologic function as a biomarker for the diagnosis and prognosis of CRPC.

METHODS

Plasma samples were collected from five healthy donors (Control, CT) and 17 CRPC patients, categorizing into two groups based on their endocrine treatment response: partial response (PR; n = 10) and progressive disease (PD; n = 7). Candidate extracellular vesicle (EV) miRNAs were identified using miRNA microarray and RT-qPCR. The biological functions of the selected miRNAs were evaluated using the MTT assay, wound healing assay, trans-well assay, and RNA sequencing in CRPC cells after transient miRNA expression.

RESULTS

Microarray analysis revealed a significant downregulation of EV-miR-6880-5p in the PD samples compared to both CT and PR samples (p < 0.01). The expression of EV-miR-6880-5p in CRPC patients was decreased compared with that CT group (p = 0.0336) using RT-qPCR. In the PR group, EV-miR-6880-5p was increased at follow-up compared with the baseline (p = 0.2803), while in the PD group, it decreased at follow-up compared with the baseline samples (p = 0.4356). Furthermore, overexpression of miR-6880-5p hampered cell proliferation, migration, and invasion, downregulated pathways associated with tumor progression, and simultaneously upregulated pathways associated with cell growth and apoptosis in CRPC cells.

CONCLUSIONS

EV-miR-6880-5p shows promise as a prognostic biomarker in patients with CRPC. Further, prospective validations are necessary to evaluate the potential of these candidate miRNAs.

Computer-aided drug discovery strategies for novel therapeutics for prostate cancer leveraging next-generating sequencing data

INTRODUCTION

Prostate cancer (PC) is the most common malignancy and accounts for a significant proportion of cancer deaths among men. Although initial therapy success can often be observed in patients diagnosed with localized PC, many patients eventually develop disease recurrence and metastasis. Without effective treatments, patients with aggressive PC display very poor survival. To curb the current high mortality rate, many investigations have been carried out to identify efficacious therapeutics. Compared to de novo drug designs, computational methods have been widely employed to offer actionable drug predictions in a fast and cost-efficient way. Particularly, powered by an increasing availability of next-generation sequencing molecular profiles from PC patients, computer-aided approaches can be tailored to screen for candidate drugs.

AREAS COVERED

Herein, the authors review the recent advances in computational methods for drug discovery utilizing molecular profiles from PC patients. Given the uniqueness in PC therapeutic needs, they discuss in detail the drug discovery goals of these studies, highlighting their translational values for clinically impactful drug nomination.

EXPERT OPINION

Evolving molecular profiling techniques may enable new perspectives for computer-aided approaches to offer drug candidates for different tumor microenvironments. With ongoing efforts to incorporate new compounds into large-scale high-throughput screens, the authors envision continued expansion of drug candidate pools.

In vivo stable 211At-labeled prostate-specific membrane antigen-targeted tracer using a neopentyl glycol structure

BACKGROUND

Prostate cancer is a common cancer among men worldwide that has a very poor prognosis, especially when it progresses to metastatic castration-resistant prostate cancer (mCRPC). Therefore, novel therapeutic agents for mCRPC are urgently required. Because prostate-specific membrane antigen (PSMA) is overexpressed in mCRPC, targeted alpha therapy (TAT) for PSMA is a promising treatment for mCRPC. Astatine-211 (211At) is a versatile α-emitting radionuclide that can be produced using a cyclotron. Therefore, 211At-labeled PSMA compounds could be useful for TAT; however, 211At-labeled compounds are unstable against deastatination in vivo. In this study, to develop in vivo stable 211At-labeled PSMA derivatives, we designed and synthesized 211At-labeled PSMA derivatives using a neopentyl glycol (NpG) structure that can stably retain 211At in vivo. We also evaluated their biodistribution in normal and tumor-bearing mice.

RESULTS

We designed and synthesized 211At-labeled PSMA derivatives containing two glutamic acid (Glu) linkers between the NpG structure and asymmetric urea (NpG-L-PSMA ((L-Glu)2 linker used) and NpG-D-PSMA ((D-Glu)2 linker used)). First, we evaluated the characteristics of 125I-labeled NpG derivatives because 125I was readily available. [125I]I-NpG-L-PSMA and [125I]I-NpG-D-PSMA showed low accumulation in the stomach and thyroid, indicating their high in vivo stability against deiodination. [125I]I-NpG-L-PSMA was excreted in urine as hydrophilic radiometabolites in addition to the intact form. Meanwhile, [125I]I-NpG-D-PSMA was excreted in urine in an intact form. In both cases, no radioactivity was observed in the free iodine fraction. [125I]I-NpG-D-PSMA showed higher tumor accumulation than [125I]I-NpG-L-PSMA. We then developed 211At-labeled PSMA using the NpG-D-PSMA structure. [211At]At-NpG-D-PSMA showed low accumulation in the stomach and thyroid in normal mice, indicating its high stability against deastatination in vivo. Moreover, [211At]At-NpG-D-PSMA showed high accumulation in tumor similar to that of [125I]I-NpG-D-PSMA.

CONCLUSIONS

[211At]At-NpG-D-PSMA showed high in vivo stability against deastatination and high tumor accumulation. [211At]At-NpG-D-PSMA should be considered as a potential new TAT for mCRPC.

Drug resistance mechanisms and treatment strategies mediated by Ubiquitin-Specific Proteases (USPs) in cancers: new directions and therapeutic options

Drug resistance represents a significant obstacle in cancer treatment, underscoring the need for the discovery of novel therapeutic targets. Ubiquitin-specific proteases (USPs), a subclass of deubiquitinating enzymes, play a pivotal role in protein deubiquitination. As scientific research advances, USPs have been recognized as key regulators of drug resistance across a spectrum of treatment modalities, including chemotherapy, targeted therapy, immunotherapy, and radiotherapy. This comprehensive review examines the complex relationship between USPs and drug resistance mechanisms, focusing on specific treatment strategies and highlighting the influence of USPs on DNA damage repair, apoptosis, characteristics of cancer stem cells, immune evasion, and other crucial biological functions. Additionally, the review highlights the potential clinical significance of USP inhibitors as a means to counter drug resistance in cancer treatment. By inhibiting particular USP, cancer cells can become more susceptible to a variety of anti-cancer drugs. The integration of USP inhibitors with current anti-cancer therapies offers a promising strategy to circumvent drug resistance. Therefore, this review emphasizes the importance of USPs as viable therapeutic targets and offers insight into fruitful directions for future research and drug development. Targeting USPs presents an effective method to combat drug resistance across various cancer types, leading to enhanced treatment strategies and better patient outcomes.

Lanthanide MOF-based luminescent sensor arrays for the detection of castration-resistant prostate cancer curing drugs and biomarkers

In recent years, castration-resistant prostate cancer (CRPC) has profoundly impacted the lives of many men, and early diagnosis of medication and illness is crucial. Therefore, a highly efficient detection method for CRPC biomarkers and curing drugs is required. However, the complex and diverse structures of CRPC drugs pose significant challenges for their detection and differentiation. Lanthanide metal-organic frameworks (Ln-MOFs) show great potential for sensing applications due to their intense and characteristic luminescence. In this work, a series of new bimetallic Ln-MOFs (EuxTb1-x-MOF) based luminescent sensor arrays have been developed to identify CRPC drugs, including in mixtures, via principal component analysis (PCA) and hierarchical cluster analysis (HCA) methods. These Ln-MOFs are built with a highly conjugated H2L linker (H2L = 5-(4-(triazole-1-yl)phenyl)isophthalic acid) and exhibit robust strong luminescence emissions (mainly located at 543 and 614 nm) and high energy transfer efficiencies. More specifically, Eu0.096Tb0.904-MOF (MOF 3) has demonstrated good sensing performances for CRPC curing drugs in real human serum samples. Furthermore, the curing drug hydroxyflutamide has been combined with MOF 3, to construct a robust composite sensing platform MOF 3@hydroxyflutamide for highly efficient detection of CRPC biomarkers such as the androgen receptor (AR) and prostate-specific antigen (PSA). Finally, luminescence lifetime measurements, zeta potential measurements, and density functional theory (DFT) calculations were performed to gain insights into the sensing mechanism.

Butyrate increases methylglyoxal production through regulation of the JAK2/Stat3/Nrf2/Glo1 pathway in castration‑resistant prostate cancer cells

Cancer cells are characterized by increased glycolysis, known as the Warburg effect, which leads to increased production of cytotoxic methylglyoxal (MGO) and apoptotic cell death. Cancer cells often activate the protective nuclear factor erythroid 2‑related factor2 (Nrf2)/glyoxalase1 (Glo1) system to detoxify MGO. The effects of sodium butyrate (NaB), a product of gut microbiota, on Nrf2/Glos/MGO pathway and the underlying mechanisms in prostate cancer (PCa) cells were investigated in the present study. Treatment with NaB induced the cell death and reduced the proliferation of PCa cells (DU145 and LNCap). Moreover, the protein kinase RNA-like endoplasmic reticulum kinase/Nrf2/Glo1 pathway was greatly inhibited by NaB, thereby accumulating MGO-derived adduct hydroimidazolone (MG-H1). In response to a high amount of MGO, the expression of Nrf2 and Glo1 was attenuated, coinciding with an increased cellular death. NaB also markedly inhibited the Janus kinase 2 (JAK2)/Signal transducer and activator of transcription 3 (Stat3) pathway. Conversely, co‑treatment with Colivelin, a Stat3 activator, significantly reversed the effects of NaB on Glo1 expression, MG-H1 production, and the cell migration and viability. As expected, overexpression of Stat3 or Glo1 reduced NaB‑induced cell death. The activation of calcium/calmodulin dependent protein kinase II gamma and reactive oxygen species production also contributed to the anticancer effect of NaB. The present study, for the first time, demonstrated that NaB greatly increases MGO production through suppression of the JAK2/Stat3/Nrf2/Glo1 pathway in DU145 cells, a cell line mimicking castration‑resistant PCa (CRPC), suggesting that NaB may be a potential agent for PCa therapy.

Evaluating first-line therapeutic strategies for metastatic castration-resistant prostate cancer: a comprehensive network meta-analysis and systematic review

Objective

This study aimed to evaluate the relative efficacy and safety of first-line treatment options for metastatic castration-resistant prostate cancer (mCRPC).

Methods

We systematically searched electronic databases, including PubMed and Web of Science, for studies published from their inception to April 3rd, 2023. Inclusion criteria were: 1) Completed Phase III or IV randomized controlled trials (RCTs) registered on ClinicalTrials.gov; 2) Patients with a confirmed diagnosis of mCRPC who had not previously received chemotherapy or novel endocrine therapies. We conducted a network meta-analysis using R software (version 3.4.0). Network graphs and risk of bias graphs were generated using Stata 14.0 and RevMan 5.4, respectively. The primary outcome was overall survival (OS), and the secondary outcome was the incidence of severe adverse events (SAEs).

Results

Seven RCTs encompassing 6,641 patients were included. The network meta-analysis revealed that both docetaxel+prednisone (DP) and cabazitaxel+prednisone (CP) significantly improved OS compared to abiraterone. Compared to placebo, DP showed comparable results to both cabazitaxel 20 mg/m^2+prednisone (C20P) and cabazitaxel 25 mg/m^2+prednisone (C25P) in terms of OS. For SAEs, both DP and C20P were superior to C25P, with no statistical difference between C20P and DP. The probability ranking plots indicated that C25P ranked highest for OS, while DP ranked highest for SAEs.

Conclusions

Based on our network meta-analysis, we recommend cabazitaxel 20 mg/m^2+prednisone (C20P) as the primary choice for first-line management of mCRPC, followed by DP. Enzalutamide and abiraterone are suggested as subsequent options. Radium-223 may be considered for patients presenting with bone metastases.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023443943.

Long-Term Control With Proton Beam Therapy for Recurrent Prostate Cancer in the Right Perineum Following Intensity-Modulated Radiation Therapy: A Case Report

Radiation therapy (RT) is commonly used for the treatment of prostate cancer, with intensity-modulated radiation therapy (IMRT) and proton beam therapy (PBT) being the utilized modalities. This case report outlines the treatment course of a recurrent prostate cancer lesion in the right perineal musculature managed with proton therapy following IMRT. A 64-year-old Japanese man, diagnosed with prostate cancer and categorized as high risk according to the National Comprehensive Cancer Network guidelines, underwent six months of androgen deprivation therapy, which included bicalutamide and degarelix acetate. Six months after completing 78 Gy in 39 fractions of IMRT, the patient reported perineal to anal pain. Laboratory tests showed an elevated serum prostate-specific antigen (PSA) level, and pelvic MRI showed a mass lesion in the right perineal musculature. Consequently, the patient was diagnosed with recurrent prostate cancer. Thereafter, the patient underwent eight cycles of systemic chemotherapy with docetaxel; however, his pain progressively worsened. Subsequently, the treatment was switched to 12 cycles of cabazitaxel, which led to gradual pain relief. The patient received PBT at 60 Gy relative biological effectiveness in 30 fractions for the recurrent lesion. Five years after PBT, pelvic MRI showed no mass lesions in the prostate or surrounding tissues. The PSA levels remained low, less than 0.008 ng/ml, and there were no apparent late complications.

An androgen receptor-based signature to predict prognosis and identification of ORC1 as a therapeutical target for prostate adenocarcinoma

Background

Aberrant activation of androgen receptor (AR) signaling plays a crucial role in the progression of prostate adenocarcinoma (PRAD) and contributes significantly to the development of enzalutamide resistance. In this study, we aimed to identify a novel AR-driven signature that can predict prognosis and endows potentially reveal novel therapeutic targets for PRAD.

Methods

The Seurat package was used to preprocess the single-cell RNA sequencing (scRNA-seq). Differentially expressed genes were visualized using limma and pheamap packages. LASSO and multi-variate Cox regression models were established using glmnet package. The package "Consensus Cluster Plus" was utilized to perform the consensus clustering analysis. The biological roles of origin recognition complex subunit 1 (ORC1) in PRAD were determined by gain- and loss-of-function studies in vitro and in vivo.

Result

We characterized the scRNA-seq data from GSE99795 and identified 10 AR-associated genes (ARGs). The ARGs model was trained and validated in internal and external cohorts. The ARGs were identified as an independent hazard factor in PRAD and correlated with clinical risk characteristics. In addition, the ARGs were found to be correlated with somatic tumor mutation burden (TMB) levels. Two groups that have distinct prognostic and molecular features were identified through consensus clustering analysis. ORC1 was identified as a critical target among these ARGs, and it ORC1 promoted proliferation and stem-like properties of PRAD cells. Chromatin immunoprecipitation (ChIP)-qPCR assay confirmed that AR could directly bind the promoter of ORC1. Activated AR/ORC1 axis contributed to enzalutamide resistance, and targeting ORC1 rendered PRAD cells more susceptible to enzalutamide.

Conclusions

This study defines an AR-driven signature that AR activates ORC1 expressions to promote PRAD progression and enzalutamide resistance, which may provide novel targets for PRAD treatment.

From modulation of cellular plasticity to potentiation of therapeutic resistance: new and emerging roles of MYB transcription factors in human malignancies

MYB transcription factors are encoded by a large family of highly conserved genes from plants to vertebrates. There are three members of the MYB gene family in human, namely, MYB, MYBL1, and MYBL2 that encode MYB/c-MYB, MYBL1/A-MYB, and MYBL2/B-MYB, respectively. MYB was the first member to be identified as a cellular homolog of the v-myb oncogene carried by the avian myeloblastosis virus (AMV) causing leukemia in chickens. Under the normal scenario, MYB is predominantly expressed in hematopoietic tissues, colonic crypts, and neural stem cells and plays a role in maintaining the undifferentiated state of the cells. Over the years, aberrant expression of MYB genes has been reported in several malignancies and recent years have witnessed tremendous progress in understanding of their roles in processes associated with cancer development. Here, we review various MYB alterations reported in cancer along with the roles of MYB family proteins in tumor cell plasticity, therapy resistance, and other hallmarks of cancer. We also discuss studies that provide mechanistic insights into the oncogenic functions of MYB transcription factors to identify potential therapeutic vulnerabilities.

Discovery of a small-molecule NDR1 agonist for prostate cancer therapy

Prostatic cancer (PCa) is a common malignant neoplasm in men worldwide. Most patients develop castration-resistant prostate cancer (CRPC) after treatment with androgen deprivation therapy (ADT), usually resulting in death. Therefore, investigating new therapeutic targets and drugs for PCa patients is urgently needed. Nuclear Dbf2-related kinase 1 (NDR1), also known as STK38, is a serine/threonine kinase in the NDR/LATS kinase family that plays a critical role in cellular processes, including immunity, inflammation, metastasis, and tumorigenesis. It was reported that NDR1 inhibited the metastasis of prostate cancer cells by suppressing epithelial-mesenchymal transition (EMT), and decreased NDR1 expression might lead to a poorer prognosis, suggesting the enormous potential of NDR1 in antitumorigenesis. In this study, we characterized a small-molecule agonist named aNDR1, which specifically bound to NDR1 and potently promoted NDR1 expression, enzymatic activity and phosphorylation. aNDR1 exhibited drug-like properties, such as favorable stability, plasma protein binding capacity, cell membrane permeability, and PCa cell-specific inhibition, while having no obvious effect on normal prostate cells. Meanwhile, aNDR1 exhibited good antitumor activity both in vitro and in vivo. aNDR1 inhibited proliferation and migration of PCa cells and promoted apoptosis of PCa cells in vitro. We further found that aNDR1 inhibited subcutaneous tumors and lung metastatic nodules in vivo, with no obvious toxicity to the body. In summary, our study presents a potential small-molecule lead compound that targets NDR1 for clinical therapy of PCa patients.

PRL-mediated STAT5B/ARRB2 pathway promotes the progression of prostate cancer through the activation of MAPK signaling

Previous study showed that higher expression of prolactin (PRL) was found in CRPC samples compared with hormone-naive prostate cancer (HNPC) and benign prostatic hyperplasia (BPH) samples. We further investigate the function of PRL in prostate cancer (PCa) and explored its downstream effects. We found heterogeneous expression of the PRLR in clinical prostate samples. The VCaP and 22Rv1 cells exhibited PRLR expression. Among the downstream proteins, STAT5B was the dominant subtype in clinical samples and cell lines. Human recombinant PRL stimulation of PCa cells with PRLR expression resulted in increased phosphorylation of STAT5B(pSTAT5B) and progression of PCa in vitro and in vivo, and STAT5B knockdown can suppress the malignant behavior of PCa. To understand the mechanism further, we performed Bioinformatic analysis, ChIP qPCR, and luciferase reporter gene assay. The results revealed that ARRB2 was the transcription target gene of STAT5B, and higher expression of ARRB2 was related to higher aggression and poorer prognosis of PCa. Additionally, Gene set enrichment analysis indicated that higher expression of ARRB2 was significantly enriched in the MAPK signaling pathway. Immunohistochemistry (IHC) demonstrated elevated pSTAT5B, ARRB2, and pERK1/2 expression levels in CRPC tissues compared to HNPC and BPH. Mechanically, ARRB2 enhanced the activation of the MAPK pathway by binding to ERK1/2, thereby promoting the phosphorylation of ERK1/2 (pERK1/2). In conclusion, our study demonstrated that PRL stimulation can promote the progression of PCa through STAT5B/ARRB2 pathway and activation of MAPK signaling, which can be suppressed by intervention targeting STAT5B. Blockade of the STAT5B can be a potential therapeutic target for PCa.

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.

Decoding the basis of histological variation in human cancer

Molecular abnormalities that shape human neoplasms dissociate their phenotypic landscape from that of the healthy counterpart. Through the lens of a microscope, tumour pathology optically captures such aberrations projected onto a tissue slide and has categorized human epithelial neoplasms into distinct histological subtypes based on the diverse morphogenetic and molecular programmes that they manifest. Tumour histology often reflects tumour aggressiveness, patient prognosis and therapeutic vulnerability, and thus has been used as a de facto diagnostic tool and for making clinical decisions. However, it remains elusive how the diverse histological subtypes arise and translate into pleiotropic biological phenotypes. Molecular analysis of clinical tumour tissues and their culture, including patient-derived organoids, and add-back genetic reconstruction of tumorigenic pathways using gene engineering in culture models and rodents further elucidated molecular mechanisms that underlie morphological variations. Such mechanisms include genetic mutations and epigenetic alterations in cellular identity codes that erode hard-wired morphological programmes and histologically digress tumours from the native tissues. Interestingly, tumours acquire the ability to grow independently of the niche-driven stem cell ecosystem along with these morphological alterations, providing a biological rationale for histological diversification during tumorigenesis. This Review comprehensively summarizes our current understanding of such plasticity in the histological and lineage commitment fostered cooperatively by molecular alterations and the tumour environment, and describes basic and clinical implications for future cancer therapy.

Identification and validation of an individualized metabolic prognostic signature for predicting the biochemical recurrence of prostate cancer based on the immune microenvironment

BACKGROUND

Prostate cancer (PCa) is the most prevalent genitourinary malignancy in men, with a significant proportion of patients developing biochemical recurrence (BCR) after treatment. The immune microenvironment and metabolic alterations have crucial implications for the tumorigenesis and progression of PCa. Therefore, identifying metabolic genes associated with the immune microenvironment holds promise for predicting BCR and improving PCa prognosis.

METHODS

In this study, ssGSEA and hierarchical clustering analysis were first conducted to evaluate and group PCa samples, followed by the use of the ESTIMATE and CIBERSORT algorithms to characterize the immunophenotypes and tumor microenvironment. The differential metabolic genes (MTGs) between groups were utilized to develop a prognostic-related signature. The predictive performance of the signature was assessed by principal component analysis (PCA), receiver operating characteristic (ROC) curve analysis, survival analysis, and the TIDE algorithm. A miRNA-MTGs regulatory network and predictive nomogram were constructed. Moreover, the expression of prognostic MTGs in PCa was detected by RT‒qPCR.

RESULTS

PCa samples from the TCGA cohort were separated into two groups: the immune-low group and immune-high group. Forty-eight differentially expressed MTGs between the groups were identified, including 37 up-regulated and 11 down-regulated MTGs. Subsequently, CEL, CYP3A4, and PDE6G were identified as the genes most strongly associated with the BCR of PCa patients and these genes were utilized to establish the MTGs-based prognostic signatures. PCA, ROC curves analysis, Kaplan-Meier survival analysis, and the nomogram all showed the good predictive ability of the signature regardless of clinical variables. Furthermore, the MTGs-based signature was indicated as a potential predictive biomarker for immunotherapy response. Nine miRNAs involved in the regulation of prognostic MTGs were determined. In addition to the CEL gene, the PDE6G and CYP3A4 genes were expressed at higher levels in PCa samples.

CONCLUSIONS

The MTGs-based signature represents a novel approach with promising potential for predicting BCR in PCa patients.

Identifying the role of MTHFD1L in prostate cancer progression from genetic analysis and experimental validation

One-carbon metabolism plays a crucial role in tumorigenesis as it supplies the one-carbon units necessary for nucleotide synthesis, epigenetic regulation, and redox metabolism, ensuring the rapid proliferation of cancer cells. However, their roles in prostate cancer progression remain poorly understood. In this study, we investigated the association between genetic variants in the one-carbon metabolism pathway and clinical outcomes in patients receiving androgen deprivation therapy for prostate cancer. The associations of 130 single-nucleotide polymorphisms located within 14 genes involved in the one-carbon metabolism pathway with cancer-specific survival (CSS), overall survival, and progression-free survival were assessed using Cox regression in 630 patients with prostate cancer. Subsequently, functional studies were performed using prostate cancer cell lines. After adjusting for covariates and multiple testing, MTHFD1L rs2073190 was found to be significantly associated with CSS (P = 0.000184). Further pooled analysis of multiple datasets demonstrated that MTHFD1L was upregulated in prostate cancer and increased MTHFD1L expression was positively correlated with tumor aggressiveness and poor patient prognosis. Functionally, MTHFD1L knockdown suppressed prostate cancer cell proliferation and colony formation. RNA sequencing and pathway analysis revealed that differentially expressed genes were predominantly enriched in the cell cycle pathway. In conclusion, genetic variants in MTHFD1L of one-carbon metabolism may serve as promising predictors, and our findings offer valuable insights into the underlying genetic mechanisms of prostate cancer progression.

Transcending frontiers in prostate cancer: the role of oncometabolites on epigenetic regulation, CSCs, and tumor microenvironment to identify new therapeutic strategies

Prostate cancer, as one of the most prevalent malignancies in males, exhibits an approximate 5-year survival rate of 95% in advanced stages. A myriad of molecular events and mutations, including the accumulation of oncometabolites, underpin the genesis and progression of this cancer type. Despite growing research demonstrating the pivotal role of oncometabolites in supporting various cancers, including prostate cancer, the root causes of their accumulation, especially in the absence of enzymatic mutations, remain elusive. Consequently, identifying a tangible therapeutic target poses a formidable challenge. In this review, we aim to delve deeper into the implications of oncometabolite accumulation in prostate cancer. We center our focus on the consequential epigenetic alterations and impacts on cancer stem cells, with the ultimate goal of outlining novel therapeutic strategies.

Serine/threonine kinase 36 induced epithelial-mesenchymal transition promotes docetaxel resistance in prostate cancer

To investigate the role and potential mechanism of serine/threonine kinase 36 (STK36) in docetaxel resistance-prostate cancer (PCa). The expression of STK36 in PCa and the correlation with clinicopathological characteristics of PCa patients were analyzed using the data from different databases and tissue microarrays. To investigate the role of STK36 on cell proliferation, invasion, and migration, STK36 was overexpressed and silenced in DU-145 and PC-3 cell lines. Cell counting kit-8 (CCK8) was used to test cell proliferation. Cell invasion and migration were detected by cell wound scratch assay and trans well, respectively. The expression profile of STK36, E-Cadherin, and Vimentin was analyzed by Western blot. Cell apoptosis was detected by the TUNEL assay. STK36 expression was upregulated in PCa tissue compared with adjacent benign PCa tissue; it was higher in patients with advanced stages compared with lower stages and was significantly correlated with decreased overall survival. Up-regulation of STK36 significantly promoted the proliferation, invasion, and migration of DU-145 and PC-3 cells and compensated for the suppression caused by docetaxel treatment in vitro. A striking apoptosis inhibition could be observed when dealing with docetaxel, although the apoptosis of DU-145 and PC-3 cells was not affected by the STK36 exclusive overexpression. Besides, E-Cadherin expression was restrained while the expression levels of vimentin were all enhanced. The knockdown of STK36 reversed the above process. STK36 up-regulation could accelerate the biological behavior and docetaxel resistance of PCa by epithelial-mesenchymal transition (EMT) activation. STK36 may be potentially used as a target in PCa resolvent with docetaxel.

A Rare Case of Neuroendocrine Prostate Cancer Detected on 68Ga - DOTANOC Positron Emission Tomography/Computed Tomography (PET/CT)

Prostate cancer is one of the most common malignancies affecting elderly men worldwide and the fifth leading cause of cancer death in men. Prostate cancer includes many histological variants with the prostatic acinar adenocarcinoma variant accounting for the majority of the diagnosed cases. Other less common histological variants are broadly classified as non-acinar carcinomas. One of the non-acinar carcinoma variants is neuroendocrine prostate cancer (NEPC). NEPC can emerge as a mechanism of treatment resistance in castration-resistant conventional prostate cancer and can also rarely be seen as a primary histological form at the time of initial diagnosis. Like other non-acinar carcinoma variants of prostate cancer, NEPC is also an aggressive variant with associated poor prognosis. Neuroendocrine tumors (NETs) are characterized by the expression of somatostatin receptors (SSTRs). Positron emission tomography/computed tomography (PET/CT) using radiolabeled somatostatin analogs like DOTANOC have been used to detect and stage these NETs. These radiolabeled somatostatin analogs also provide the option of treatment of these tumors and have been used in peptide receptor radionuclide therapy of these tumors. NEPC being a neuroendocrine malignancy also expresses SSTRs and hence can be detected with PET/CT radiotracers like 68Gallium-labeled somatostatin analogs. We here report a case of metastatic treatment-emergent NEPC detected on 68Ga - DOTANOC PET/CT.

Zhoushi Qi Ling decoction inhibits the progression of castration-resistant prostate cancer in vivo by regulating macrophage infiltration via IL6-STAT3 signaling

Background and aim

Prostate cancer is a leading malignant tumor in men, associated with a high rate of mortality. Androgen deprivation therapy is commonly used to treat prostate cancer, which contributes to the progression of castration-resistant prostate cancer (CRPC). The current therapy has a low survival rate in patients with CRPC. Our study aims to develop a novel effective approach for CRPC treatment and improve survival benefits.

Experimental procedure

CRPC cell line PC-3-Luc expressing luciferase and the CRPC cell line PC-3-IL6-Luc stably overexpressing IL-6 were used to establish the xenograft tumor mouse model. The tumor was monitored weekly using Bioluminescence imaging. Infiltrated macrophages were quantified by fluorescence-activated cell sorting using flow cytometry. IL6 mRNA level was determined using quantitative real-time PCR. The protein levels of total STAT3 and phosphorylated STAT3 were determined using Western blot.

Results and conclusion

Zhoushi Qi Ling decoction (ZQD) treatment significantly reduced PC3 the xenograft tumor progression and the number of infiltrated macrophages when compared with saline treatment. IL6 mRNA level was remarkedly suppressed by ZQD treatment. Notably, the protein level of phosphorylated STAT3 was significantly decreased in PC3 the xenograft tumor treated with ZQD compared to saline treatment. Our findings demonstrated that ZQD treatment significantly reduced the progression of prostate cancer, evidenced by the reduced population of infiltrated macrophages and the inhibition of the IL6/STAT3 pathway.