Castration-resistant Prostate Cancer Patients Research Articles

High 11-ketotestosterone linked to shorter time to castration resistance in recurrent non-metastatic prostate cancer.

The contribution of 11-oxygenated androgens to the progression of lethal prostate cancer (PCa) remains unresolved. We hypothesized that evaluating circulating levels of 11-oxygenated androgens, such as the androgen receptor agonist 11-ketotestosterone (11KT), could serve as a potential predictor of the onset of castration resistant prostate cancer (CRPC). We used mass spectrometry to quantify 11-oxygenated androgens in post-operative plasma samples acquired from 145 patients who subsequently received androgen deprivation therapy (ADT) for biochemical recurrence (BCR) and achieved castrated testosterone (T) levels. Kaplan-Meier survival analyses and multivariable Cox models were used to investigate relationships between steroids and CRPC. Of 145 patients, 31 developed CRPC with a median time to CRPC of 57 months. 11-oxygenated androgens levels were unaffected by ADT, which stands in contrast to the observed changes in T and other steroids. 11KT was the most abundant androgen but was not linked to clinical features. Kaplan-Meier analysis revealed that 11KT levels above the median of 273 pg/mL were associated with a shorter time to CRPC (P = 0.03). In multivariable analyses, this was supported with an adjusted hazard ratio of 2.17 (95% confidence interval (CI) 0.99-4.71; P = 0.05). 11KT is a key component of the hormonal profile predictive of earlier onset of CRPC. Enhancing our understanding of the specific role of 11KT in the progression to CRPC could help optimize hormonal therapy for castration sensitive PCa and CRPC patients.

Abstract B019: Androgen receptor-regulated lncRNA PRCAT71 promotes AR signaling through the interaction with RBPs in prostate cancer

Abstract Prostate cancer (PCa) is the second leading cause of cancer death in American men. PCa patients usually receive androgen deprivation therapy but eventually, they will relapse and tumors become castration-resistant PCa (CRPC) without effective treatments, highlighting the urgent need to develop better therapeutics to target advanced PCa. The main mechanism identified leading to castration resistance is aberrant androgen receptor (AR) reactivation, including AR overexpression. Approximately 80% of CRPC patients have a marked increase in AR mRNA and protein expression. Emerging evidence suggests genomic and transcriptomic changes insufficiently predict biology and mRNA and protein expression levels frequently do not correlate. Posttranscriptional regulation of AR mRNA can lead to AR overexpression. RNA binding proteins (RBPs) and non-coding RNAs (ncRNAs), such as microRNAs, long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), can control gene expression via direct binding to mRNAs and regulating mRNA processing, modification, and translation. Here in this study, we identified a novel PCa-specific lncRNA, PRCAT71, which is higher expressed in prostate tumor tissues than in benign tissues. Silencing PRCAT71 suppressed the cancerous properties of PCa cells, and reduced AR mRNA and protein expression levels, leading to inhibited AR signaling. We further uncovered that PRCAT71 formed an RNA-RNA duplex with AR mRNA, which enhanced the stability of AR mRNA. RNA pulldown assay identified PRCAT71- interacted RBPs. Silencing PRCAT71 reduced the interaction between key RBPs and AR mRNA, which is related to PRCAT71 regulating AR mRNA stability. Interestingly, PRCAT71 is transcriptionally regulated by AR-driven enhancers, thus forming a positive regulatory loop between AR and PRCAT71 in PCa. The high expression of PRCAT71 and key RBPs in PCa tumors are positively correlated with PSA level, AR activity and indicate worse patient overall survival and metastasis-free survival. Our study revealed a novel regulatory mechanism by which lncRNA PRCAT71 enhances the interaction of key RBPs with AR mRNA, stabilizes AR mRNA and promotes AR expression and PCa progression. Targeting PRCAT71-RBPs is a promising approach to treating CRPC. Citation Format: Yongyong Yang, Ting-You Wang, Qianru Li, Adam B Weiner, Jiawen Lu, Yanan Ren, Qingxiang Guo, Chaehyun Yum, Qi Liu, Rui Wang, Zhe Ji, Tamara L Lotan, Edward M Schaeffer, Rendong Yang, Qi Cao. Androgen receptor-regulated lncRNA PRCAT71 promotes AR signaling through the interaction with RBPs in prostate cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: RNAs as Drivers, Targets, and Therapeutics in Cancer; 2024 Nov 14-17; Bellevue, Washington. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(11_Suppl):Abstract nr B019.

Fuzheng-Buyi formula for treating castration-resistant prostate cancer: A systematic review and meta-analysis.

The study was designed to systematically evaluate the efficacy and safety of Fuzheng-Buyi formula in treating castration-resistant prostate cancer (CRPC). A computer-based search were conducted in the databases, including CNKI, WanFang Data, VIP, CBM, PubMed, EMbase, and the Cochrane database to identify all randomized controlled trials. The studies investigating the efficacy and safety of Fuzheng-Buyi formula combined with Western medicine for the treatment of CRPC were included from January 1st, 2010 to December 31st, 2023. The quality of the included studies was evaluated according to the Cochrane Handbook manual, and meta-analysis was performed using Review Manager 5.3 and R Studio 4.2.3 software. In this study, a total of 18 trials were included, encompassing a population of 1093 patients diagnosed with CRPC. The results of the meta-analysis showed that the combination of Fuzheng-Buyi formula and Western drugs was more effective in increasing the overall efficacy rate (risk ratio = 1.31, 95% confidence interval [CI] [1.17, 1.46], P < .00001), decreasing Traditional Chinese Medicine syndrome score (mean difference [MD] = -4.40, 95% CI [-6.10, -2.70], P < .00001), and quality of life scale (physiological condition MD = -2.31, 95% CI [-3.13, -1.48], P < .00001; social well-being MD = 1.26, 95% CI [0. 59, 1.94], P = .0002; emotional well-being MD = -2.04, 95% CI [-2.96, -1.12], P < .00001; functional well-being MD = -3.18, 95% CI [2.11, 4.26], P < .00001; others should be paid to MD = -3.15, 95% CI [-4.93, -1.37], P = .0005) compared with the Western medicine alone. And the incidence of adverse events was significantly lower in the combination treatment group compared with Western medicine group (risk ratio = 0.58, 95% CI [0.46, 0.73], P < .00001). The combination of Fuzheng-Buyi formula and Western medicine was more effective in improving the clinical efficacy and quality of life of CRPC patients, with lower incidence of adverse events compared with Western medicine alone.

Influence of metastatic sites and burden on oncological outcomes in patients progressing to metastatic castration resistant prostate cancer

PurposeMetastatic castration-resistant prostate cancer (mCRPC) patients harbor reduced life expectancy after first-line treatment progression. Currently, no information is available regarding the influence of metastatic sites and osseous burden on progression-free (PFS) and overall survival (OS) of mCRPC patients.MethodsWe relied on the Frankfurt Metastatic Cancer Database of the Prostate (FRAMCAP) database to select patients progressing to mCRPC and stratified them according to lymph node vs. osseous vs. visceral metastatic sites. Moreover, we stratified osseous mCRPC patients regarding the number of metastatic lesions. Endpoints were PFS and OS in uni- and multivariable Cox regression models.ResultsOf 363 patients, 9.4% harbored M1a vs. 78% M1b vs. 12% M1c mCRPC with significantly higher PSA in M1b (9 vs. 22 vs. 8ng/ml). Rates of DeNovo (15% vs. 60% vs. 56%) were significantly lower in the M1a mCRPC group, compared to M1b and M1c (p < 0.001). In PFS analyses, a median of 12.7 vs. 10.1 vs. 15.9 months for M1a vs. M1b vs. M1c mCRPC was observed (p > 0.05). In multivariable Cox regression models, M1c mCRPC was independently at higher risk for progression (hazard ratio [HR]: 5.93, p = 0.048), relative to M1a. Regarding OS, significant differences were observed (p = 0.002), with median OS of 58 vs. 42 vs. 25 months for M1a vs. M1b vs. M1c mCRPC and corresponding HRs of 1.54 (p = 0.11) and 2.76 (p < 0.01). In multivariable models M1c mCRPC was associated with higher risk of death (HR: 3.56, p = 0.049), relative to M1a. No differences were observed after stratification according to number of bone lesions (all p ≥ 0.05).ConclusionM1c mCRPC patients are independently at higher risk for progression and death, while M1a patients harbor best cancer-control outcomes.

Nodularin-R Synergistically Enhances Abiraterone Against Castrate- Resistant Prostate Cancer via PPP1CA Inhibition.

Clinically, most prostate cancer (PCa) patients inevitably progress to castration-resistant prostate cancer (CRPC) with poor prognosis after androgen deprivation therapy (ADT), including abiraterone, the drug of choice for ADT. Therefore, it is necessary to explore the resistance mechanism of abiraterone in depth. Genome-wide CRISPR/Cas9 knockout technology was used to screen CRPC cell line 22Rv1 for abiraterone-resistant genes. Combined with bioinformatics, a key gene with high expression and poor prognosis in CRPC patients was screened. Then, the effects of target gene on abiraterone-resistant 22Rv1 cell function were explored by silencing and overexpression. Further, a natural product with potential targeting effect was identified and validated by molecular docking and protein expression. Molecular dynamics simulations revealed potential mechanism for the natural product affecting target protein expression. Finally, the combined anti-CRPC effects of the natural product and abiraterone were validated by cellular and invivo experiments. Five common resistance genes (KCNJ3, COL2A1, PPP1CA, MDH2 and EXOSC5) were identified successfully, among which high PPP1CA expression had the worst prognosis for disease-free survival. Moreover, PPP1CA was highly expressed in abiraterone-resistant 22Rv1 cells. Silencing PPP1CA increased cell sensitivity to abiraterone while promoting apoptosis and inhibiting clone formation. Overexpressing PPP1CA exerted the opposite effects. Molecular docking revealed the binding mode of the natural product nodularin-R to PPP1CA with a dose-dependent manner for inhibition. Mechanistically, nodularin-R attenuates the interaction between PPP1CA and USP11 (deubiquitinating enzyme), potentially promoting PPP1CA degradation. Additionally, combination of 2.72 μM nodularin-R and 54.5 μM abiraterone synergistically inhibited the resistant 22Rv1 cell function. Invivo experiments also revealed that combination therapy significantly inhibited tumour growth and reduced inducible expression of PPP1CA. PPP1CA is a key driver for abiraterone resistance, and nodularin-R enhances the anti-CRPC effects of abiraterone by inhibiting PPP1CA.

Development and validation of prognostic model for metastatic castration-resistant prostate cancer patients treated with first-line abiraterone or enzalutamide.

IntroductionOver the years, several prognostic models were developed in patients receiving chemotherapy for metastatic castration resistant prostate cancer (mCRPC), while data on androgen-receptor signaling inhibitors (ARSI) in a real-world setting are limited. Patients and methodsWe compared a consecutive series of 565 mCRPC patients receiving first-line ARSI at four high-volume Italian Centers (development set) to an external series of 180 patients receiving the same treatment at another Italian high-volume Center (training set), between 2011 and 2022.Sixteen clinical and baseline laboratory variables were selected to develop a prognostic model. Patients were categorized into risk groups according to the number of independent factors positively associated with overall survival (OS). ResultsIn the development cohort, after a median follow-up of 21.1 months, the median OS was 30.4 months (95% CI 27.5-33.4). At the multivariate analysis, seven variables [age, prostate specific antigen (PSA) doubling time, baseline levels of hemoglobin, PSA, time to castration resistance, ECOG PS and bone metastases number) were included into the final model.The median OS was 13.4, 25.7 and 46.4 months in poor (0-2 factors), intermediate (3-4 factors) and good (≥5 factors) prognosis group, respectively.The application of the model to the validation set confirmed its ability to prognosticate for OS. The model c-indexes were 0.68 (95% CI 0.64-0.72) and 0.75 (95% CI 0.68–0.81) in the development and validation cohort, respectively. ConclusionsOur model, based on clinical and laboratory variables readily assessable in clinical practice, might prognosticate the OS of mCRPC patients receiving first-line ARSI. Micro AbstractA retrospective study comparing a development to a validation cohort of mCRPC patients receiving ARSI found a new prognostic model. It included seven clinical and baseline laboratory variables and confirmed its ability to prognosticate for OS.

Insufficient Effective Time of Suberanilohydroxamic Acid, a Deacetylase Inhibitor, Treatment Promotes PC3 Cell Growth.

Castration-resistant prostate cancer (CRPC) contributes mostly to prostate cancer-specific mortality, and conventional castration therapy is almost ineffective, new therapies are needed. As a new potential anti-cancer drug, histone deacetylases (HDACs) inhibitors were demonstrated to be effective in inhibiting drug-resistance cancers in preclinical studies, but the results from clinical trials on CRPC patients were disappointing, and the reasons are unknown. In this study, we investigated the effect of suberanilohydroxamic acid (SAHA), a broad-spectrum pan-HDAC inhibitor, on proliferation, apoptosis, cell cycle progression in PC3 cells, and found that, unlike significant inhibiting effects at high-dose, low-dose SAHA significantly promoted PC3 cell growth. Further colony formation assay showed that the inhibitory effect of SAHA is also dependent on the treatment time, high-dose SAHA also exhibited promoting effect on PC3 cells when the treatment time was insufficient. However, this effect was not observed in another CRPC cell line, DU145, or another HDAC inhibitor, Trichostatin A (TSA). Our results indicate that, instead of inhibitory effect, SAHA would promote PC3 cell growth if the dose is low or the treatment time is insufficient, but this effect has not been observed in other CRPC cell line or HDAC inhibitors.

Assessment of the therapeutic efficacy of [177Lu]Lu-PSMA-X compared to taxane chemotherapy in taxane-chemo-naïve patients with metastatic castration-resistant prostate cancer: A systematic review and meta-analysis.

Radioligand therapy (RLT) with 177Lu-labelled prostate specific membrane antigen ([177Lu]Lu-PSMA-X, referring with "PSMA-X" to a generic PSMA chemical compound) inhibitors has emerged as a viable treatment option in metastatic castration resistant prostate cancer patients having previously progressed on taxane and androgen receptor inhibitors. The aim of this study was to perform a systematic review and meta-analysis to assess the therapeutic efficacy of [177Lu]Lu-PSMA-X compared to taxane chemotherapy in taxane-chemo-naïve patients with metastatic castration-resistant prostate cancer. Searches in several bibliographic databases were made using relevant key words, and articles published up to March 2024 were included. The endpoints included prostate specific antigen (PSA) response rate (RR), progression-free survival, and overall survival. Individual patient data were pooled when feasible. PSA50 was defined as the median proportion of patients achieving at least a 50% decline in serum PSA from baseline. A meta-analysis of the PSA50 response rate (proportion meta-analysis) was performed, generating pooled estimates and 95% confidence intervals (95% CI). From the initially selected 8,414 studies published between 2019 and 2023, 24 were included in the [177Lu]Lu-PSMA-X treated group and 17 in the taxane treated group. Our findings show that [177Lu]Lu-PSMA-X RLT yielded comparable PSA50 responses in taxane-naïve patients versus those receiving taxane chemotherapy, despite considerable study heterogeneity. Notably, the taxane-naïve group had more extensive pretreatment. This meta-analysis combines the largest cohorts of taxane-naïve mCRPC patients treated with [177Lu]Lu-PSMA-X RLT and taxane-treated mCRPC. It underscores similar PSA50 response rates in both groups, suggesting a potential role for [177Lu]Lu-PSMA-X RLT in taxane-naïve patients who cannot or choose not to undergo chemotherapy.

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.

Comparison of abiraterone, enzalutamide, and apalutamide for metastatic hormone-sensitive prostate cancer: A multicenter study.

We aimed to assess the differential efficacy and safety of androgen receptor pathway inhibitors (ARPI), such as abiraterone, enzalutamide, and apalutamide, in patients with metastatic hormone-sensitive prostate cancer (mHSPC) in a real-world practice setting. We retrospectively reviewed the records of consequent 668 patients with mHSPC treated with ARPI plus androgen deprivation therapy between September 2015 and December 2023. Based on the LATITUDE criteria, the comparison among abiraterone, enzalutamide, and apalutamide was exclusively conducted in high-risk patients. Prostate-specific antigen (PSA) responses such as the achievement of 95% and 99% PSA decline, overall survival (OS), cancer-specific survival (CSS), time to castration-resistant prostate cancer (CRPC), and the incidence of adverse events (AEs) were compared. All two-group comparisons relied on propensity score matching (PSM) to minimize the effect on possible confounders. In total, 297 patients with high-risk mHSPC treated with abiraterone, 127 with enzalutamide, and 142 with apalutamide were compared. There were no differences in time to CRPC (p = 0.13), OS (p = 0.7), and CSS (p = 0.5) among the three ARPIs. No differences were observed in the achievement rates for 95% PSA decline at 3 months among the three ARPIs, while abiraterone was significantly better in 99% PSA decline achievement compared to apalutamide (72% vs. 57%, p = 0.003). The aforementioned oncologic outcomes were sustained even when performing PSM analyzes. Although skin rash for APA (34%) was the highest incidence of AEs, there were no differences in the rates of severe AEs across the three ARPIs. Enzalutamide resulted in the lowest treatment discontinuation rates (10%) other than disease progression compared to the other regimens. Abiraterone, enzalutamide, and apalutamide have comparable oncologic outcomes in terms of OS, CSS, and time to CRPC in patients with high-risk mHSPC. Our data on differential treatment discontinuation rates, PSA response, and AE profiles can help guide clinical decision-making.

Navigating therapeutic sequencing in the metastatic castration-resistant prostate cancer patient journey.

Novel therapies for metastatic castration-resistant prostate cancer (mCRPC) have improved patient outcomes. However, there is uncertainty on the optimal selection of therapeutic agents for subsequent lines of therapy. We conducted a comprehensive review of published evidence from pivotal clinical trials and recent guidelines for the treatment of mCRPC. We further identify gaps in knowledge and areas for future research. Key considerations to help guide treatment selection for patients with mCRPC include personal treatment history, individual clinical characteristics, symptoms, prognosis, availability of clinical trials, and other patient-specific factors. Genetic testing and prostate-specific membrane antigen-targeted imaging are important tools to evaluate candidacy for newer therapeutic options such as poly (ADP-ribose) polymerase inhibitors, alone or in combination with androgen receptor pathway inhibitors, and [177Lu]Lu-PSMA-617. This article provides an overview of the evolving treatment landscape of mCRPC, discussing guideline-recommended treatment options and data from key clinical trials, while highlighting ongoing trials that may impact the future treatment landscape. Recommendations for optimal treatment sequencing based on individual patient factors are provided.

Prognostic Role of PSMA-Targeted Imaging in Metastatic Castration-Resistant Prostate Cancer: An Overview.

Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) has gained a primary role in prostate cancer (PCa) imaging, overcoming conventional imaging and prostate-specific antigen (PSA) serum levels, and has recently emerged as a promising technique for monitoring therapy response in metastatic castration-resistant prostate cancer (mCRPC) patients treated with novel hormonal therapy, taxanes, and radioligand therapy (RLT). In this review, we aim to provide an overview of the most relevant aspects under study and future prospects related to the prognostic role of PSMA PET/CT in mCRPC. A systematic literature search was performed in the following databases: MEDLINE, PubMed, and EMBASE databases. The study focused exclusively on English-language studies, excluding papers not pertinent to the topic. PSMA PET imaging offers a higher sensitivity and specificity than conventional imaging and provides accurate staging and efficient diagnosis of distant metastases. The data presented herein highlight the usefulness of PET in risk stratification, with a prognostic potential that can have a significant impact on clinical practice. Several prospective trials are ongoing and will shortly provide more evidence supporting the prognostic potential of PET PSMA data in this clinical scenario. Current evidence proves the prognostic role of PSMA PET/CT in different settings, with raising relevance also in the context of mCRPC.

Prognostic Outcomes and Predictive Factors in Non-Metastatic Castration-Resistant Prostate Cancer Patients Not Treated with Second-Generation Antiandrogens.

Background/Objectives: Patients with non-metastatic castration-resistant prostate cancer (nmCRPC) and high-risk features frequently have progression to life-threatening metastasis without second-generation antiandrogens. This study investigated nmCRPC patients for the survival and prognostic factors from a cohort before the approved use of second-generation antiandrogens. Methods: From March 2016 to January 2021, 326 patients treated with second-generation antiandrogens for metastatic castration-resistant prostate cancer (mCRPC) or metastatic castration-sensitive prostate cancer were retrieved. Forty-four patients experiencing nmCRPC with no use of second-generation antiandrogens were reviewed. The prognostic factors, at initial diagnosis or at nmCRPC, associated with metastasis-free survival (MFS) and overall survival (OS) were analyzed. Results: The median follow-up time after nmCRPC was 46 months. The median PSA level at nmCRPC was 2.7 ng/mL. Thirty-eight of forty-four patients with nmCRPC had a PSA doubling time (PSADT) of 10 months or shorter, and the median PSADT was 4 months. The median OS from nmCRPC was 53 months, and the median interval for nmCRPC patients progressing to mCRPC was 20 months. Upon univariate analysis, PSADT < 10 months (p = 0.049) and the very-high-risk group at the initial diagnosis (p = 0.043) were associated with significantly shorter post-nmCRPC MFS. The very-high-risk group (p = 0.031) was associated with significantly worse post-nmCRPC OS. In terms of survivals from the initial diagnosis of prostate cancer, Gleason grade ≥ 8 was the only independent factor with MFS and OS. Conclusions: Without second-generation antiandrogens, nmCRPC patients with PSADT <10 months and in the initial very-high-risk group developed subsequent mCRPC in a significantly faster fashion. Patients of the very-high-risk group had shorter survival rates after nmCRPC.

NFYA-mediated promotion of castration-resistant prostate cancer progression through EGR4 regulation

This research investigates the intricate involvement of nuclear Transcription Factor Y Subunit Alpha (NFYA) in the advancement of castration-resistant prostate cancer (CRPC) and its consequential impact on early Growth Response 4 (EGR4) expression. NFYA demonstrates a significant elevation in CRPC tissues and cell lines, displaying robust upregulation in metastatic prostate cancer (mPCa) samples, closely associated with the Gleason score. Immunohistochemistry validates heightened nuclear staining of NFYA in CRPC patients, highlighting its crucial role in the progression of advanced prostate cancer. Silencing NFYA through siRNA in androgen-independent cell lines markedly impedes cell growth and migration, emphasizing NFYA’s pivotal role in promoting CRPC behavior. RNA-seq analysis identifies EGR4 as a downstream target of NFYA, with both genes consistently upregulated in CRPC. Validating this finding, heightened expression of EGR4 is observed in CRPC samples. In vivo studies utilizing a mouse model demonstrate that NFYA silencing substantially inhibits LNCaP-AI/22RV1shNFYA xenograft tumor growth, accompanied by reduced expression of EGR4 and Ki67. This comprehensive study reveals the multifaceted role of NFYA in CRPC progression, elucidates its downstream impact on EGR4, and underscores the therapeutic potential of targeting NFYA to inhibit CRPC growth in vivo. These findings contribute valuable insights into potential therapeutic strategies for managing CRPC.

7906 Nanoencapsulated Curcumin-Piperine Complex: A Breakthrough In Targeting CYP17A1 For Castration Resistant Prostate Cancer Therapy

Abstract Disclosure: J. Yakubu: None. Nanoencapsulated Curcumin-Piperine Complex: A Breakthrough in Targeting CYP17A1 for Castration Resistant Prostate Cancer Therapy. Jibira Yakubu a,b,c, Oya Taritd, Evangelos Natsaridisd, Amit V. Pandey a,ba Translational Hormone Research Program, Department of Biomedical Research, Faculty of Medicine, b Paediatric Endocrinology, Diabetology and Metabolism, University Children’s Hospital, Inselspital, Bern, c Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland. d Biointerfaces, Institute of Chemistry and Bioanalytics, University of Life Sciences FHNW, Muttenz, Switzerland. Abstract: Androgens play a pivotal role in prostate cell survival and are implicated in both early-stage and advanced, castration-resistant prostate cancer (CRPC). In CRPC patients on CYP17A1 inhibitors, the development of drug resistance and hypertensive crisis through the inhibition of CYP21A2 and or its substrate are a recognized challenge. Given its crucial role in androgen production, CYP17A1 has become a major target for cancer therapies. In this study, we employed a mini-evaporation technique to nanoencapsulate curcumin, exploring its impact on CYP17A1 activity in human adrenal NCI-H295R cells. We performed steroid profiling with LC-MS, as well as gene and protein expression studies. Initial results demonstrated that curcumin nanoparticles exhibited superior efficacy in reducing CYP17A1 activity compared to known drug Abiraterone acetate. Curcumin and piperine combined in nano-capsules greatly increased the inhibitory effects on CYP17A1 activity. Furthermore, ongoing studies include western blot investigation of the drug's interaction with the CYP17A1 protein and cell cycle effects. We confirmed the efficacy of our nano formulation by testing its impact on the growth of androgen-sensitive prostate cancer cell lines. Notably, nanoencapsulation improved curcumin's inhibitory effects on DHEA production via CYP17A1. Surprisingly, the curcumin-piperine nano-capsules enhanced these effects while having no effect on CYP21A2, offering a promising option for prostate cancer treatment. Our study reveals the promise of nanoencapsulated curcumin-piperine as a game-changing method for targeting CYP17A1 for improved prostate cancer therapy. The synergistic benefits observed in our study open new avenues for addressing the difficulties associated with androgen deprivation therapy. Funding: Cancer Research Switzerland grant number: KFS 5557-02-2022 Presentation: 6/3/2024

B-255 Identification of the protein expression of Androgen Receptor variants using Targeted proteomics in clinical Castration Resistant Prostate Cancer models

Abstract Background Castration Resistant Prostate Cancer (CRPC) is a treatment resistant form of prostate cancer (PCa). Currently, there is not a way to identify which patients will develop this resistance before full blown CRPC develops. Therefore, all PCa treatment approaches are similar yet this results in tumor regression in some cases and progression in others. Targeting the androgen receptor (AR) is still the main focus of current therapies even in CRPC. Emergence of AR splice variants (AR-Vs) after initial treatment is thought to be one of the primary mechanisms of resistance. AR-Vs lack the ligand binding domain rendering Androgen Deprivation Therapy (ADT) ineffective in tumors expressing these variants. Recent work has identified the DNA and RNA species of ARVs in CRPC but investigation into whether the protein is translated are unknown. One exception is the approval of an antibody test that detects a specific AR-v, AR-v7, from the blood of PC patients and predicts ADT response. However, there are instances where a patient may not express ARv7 and are still resistant to ADT. This may suggest that other AR-Vs, not currently detected at the protein level, are important predictors for ADT response. Methods The primary goal of this work is to expand the protein identification of known and unknown AR-Vs that may predict response to ADT using targeted liquid chromatography tandem mass spectrometry (LC-MS/MS). We developed the AR-V targeted LC-MS/MS assay by first designing AR splice variants from unique splice regions via RNA-guided sequences translated to amino acid sequences. The AR-variants full amino acid sequences were then in-silico trypsin digested using Expasy software tool that generated tryptic peptides. Blast analysis of the AR-V peptides was performed where no overlap with other human proteins was observed. These AR-V peptide sequences were commercially synthesized along with heavy isotopically analogs to be used as internal standards in the LC-MS/MS method. The method examined 9 peptides and included 2 to 3 MRM transitions per peptide and calibration curves were constructed using unlabeled peptides. Specimens examined consisted of a panel of PCa cell lines (n= 6), CRPC patient derived xenografts tumors (PDX) (n=4) and a negative control cell line (no androgen receptor expression), Cos-1, which served with a dual function and was used as matrix for peptide MRM optimization experiments. Linearity and sensitivity for each peptide included in the method was examined using calibration curves. Results The targeted MRM approached was successfully achieved for the quantification of 9 peptides from 8 proteins in 6 PCa cell lines and 4 PDX tumor specimens. Out of the 8 proteins evaluated, we observed 3 known targets (AR-exon1, AR-V7 and AR-V12) and 4 novel AR-Vs in 22Rv1 PCa cell lines. Additionally, CRPC PDX were assessed where 3 novel AR-Vs were detected. Conclusions These preliminary results using a LC-MS/MS platform show promising identification and quantification of novel AR-Vs that have not been measured before at the protein level. Subsequent analysis of larger cohorts will further elucidate AR-Vs role in PCa treatment resistance mechanisms and possibly assist in future treatment approaches.

Statin use and oncological outcomes in a propensity-matched cohort of nonmetastatic castration resistant prostate cancer patients of the ARAMIS trial

IntroductionWhile observational studies suggest favorable associations between statin use and prostate cancer (CaP) outcomes, data from randomized-controlled trials remain inconclusive. Our study explores the relationship between statin use and survival outcomes in the context of the phase III ARAMIS study, a trial of darolutamide in the treatment of nonmetastatic castration-resistant prostate cancer. MethodsWe reviewed all 1,509 patients in the ARAMIS trial. Statin use was identified at baseline. Statin users were matched 1:2 with nonusers using a propensity score matching model. The primary endpoint was metastasis-free survival (MFS). Kaplan-Meier curves were plotted for MFS comparing statin users and nonusers across ARAMIS trial arms. A multivariate Cox proportional hazards model was fitted using the propensity-matched cohort and incorporating statin use and all covariates. ResultsOf the 1,509 patients in ARAMIS, 334 (22.1%) were statin users. We matched 297 statin users to 550 nonusers. Characteristics appeared well balanced. Among nonusers, 331 (60.3%) and 219 (39.7%) were in the ARAMIS darolutamide and placebo arms, respectively. Among statin users, 179 (60.3%) and 118 (39.7%) were in the ARAMIS darolutamide and placebo arms, respectively. Overall, we found no significant difference in MFS between statin users and nonusers (HR 1.05, 95% CI 0.80–1.38 P = .72). However, we found significant interaction between statin use and ARAMIS trial arm. Specifically, statin use had a stronger association with MFS in the placebo arm (P = 0.024). However, this is likely coincidental and due to the statin-placebo patients having higher nodal positivity than the nonusers-placebo patients (14.3% vs. 5.5%). Statin use was similarly not associated with the secondary outcomes of PSA progression-free survival (P = 0.42), time-to-pain progression (P = 0.85), or overall survival (P = 0.15). ConclusionsIn our secondary analysis of the ARAMIS trial, statin users had similar MFS and secondary outcomes compared to nonusers. These results suggest pursuing further statin synergies with amide-based androgen receptor axis target agents may not be fruitful.

Evaluation of glucocorticoid-related genes reveals GPD1 as a therapeutic target and regulator of sphingosine 1-phosphate metabolism in CRPC

Prostate cancer (PCa) is an androgen-dependent disease, with castration-resistant prostate cancer (CRPC) being an advanced stage that no longer responds to androgen deprivation therapy (ADT). Mounting evidence suggests that glucocorticoid receptors (GR) confer resistance to ADT in CRPC patients by bypassing androgen receptor (AR) blockade. GR, as a novel therapeutic target in CRPC, has attracted substantial attention worldwide. This study utilized bioinformatic analysis of publicly available CRPC single-cell data to develop a consensus glucocorticoid-related signature (Glu-sig) that can serve as an independent predictor for relapse-free survival. Our results revealed that the signature demonstrated consistent and robust performance across seven publicly accessible datasets and an internal cohort. Furthermore, our findings demonstrated that glycerol-3-phosphate dehydrogenase 1 (GPD1) in Glu-sig can significantly promote CRPC progression by mediating the cell cycle pathway. Additionally, GPD1 was shown to be regulated by GR, with the GR antagonist mifepristone enhancing the anti-tumorigenic effects of GPD1 in CRPC cells. Mechanistically, targeting GPD1 induced the production of sphingosine 1-phosphate (S1P) and enhanced histone acetylation, thereby inducing the transcription of p21 that involved in cell cycle regulation. In conclusion, Glu-sig could serve as a robust and promising tool to improve the clinical outcomes of PCa patients, and modulating the GR/GPD1 axis that promotes tumor growth may be a promising approach for delaying CRPC progression.

Germline and somatic testing for homologous repair deficiency in patients with prostate cancer (part 1 of 2).

Unfortunately, not all metastatic castration resistant prostate cancer (mCRPC) patients receive available life-prolonging systemic therapies, emphasizing the need to optimize mCRPC treatment selections. Better guidelines are necessary to determine genetic testing in prostate cancer. In this two-part expert opinion-based guide, we provide an expert consensus opinion on the utilization of germline and somatic testing to detect HRR alterations in patients with mCRPC. This guide was developed by a multidisciplinary expert panel that convened in 2023-2024, including representatives from medical oncology, urology, radiation oncology, pathology, medical genomics, and basic science. We argue for the widespread adoption of germline testing in all patients with prostate cancer and for somatic mutations testing in patients at the time of recurrent/metastatic disease. In this first part, we review how genomic testing is performed. We also review how to overcome certain barriers to integrate genetic and biomarker testing into clinical practice.

The role of Cabazitaxel in patients with castration-resistant and osseous metastases prostate cancer. A Hellenic Cooperative Oncology Group Phase II Study.: Cabazitaxel in mCRPC patients with osseous metastases

BackgroundCabazitaxel is an effective treatment in metastatic castration-resistant prostate cancer (mCRPC) patients previously exposed to docetaxel and novel hormonal treatments. Understanding the molecular biology of mCRPC disease and taking into account the several approved treatment options, biomarkers are needed to guide decision making including cabazitaxel treatment. MethodsCababone was a phase II translational study that attempted to identify predictors of cabazitaxel efficacy. mCRPC with documented bone metastases were enrolled prospectively and treated with cabazitaxel 25mg/m2 every three weeks. Prostate cancer biopsies, bone marrow aspirates and blood samples were collected for translational research. ResultsSixty patients were enrolled and 59 received treatment according to protocol. Six-month progression free survival (PFS) rate was 47% (95% CI: 33% - 59%) and 12-month Overall Survival (OS) rate was 70% (95% CI: 56% - 80%). Patients with reactive hematopoiesis had improved PFS and OS with cabazitaxel treatment. Mutations in HRR genes were detected in 7 patients. ConclusionsNo differences in cabazitaxel efficacy were noted according to mutational status of HRR genes analyzed. No new safety issues were detected. In conclusion, CabaBone confirmed efficacy of cabazitaxel in mCRPC patients including the subgroup of patients with HRR mutations. Reactive hematopoiesis in bone marrow biopsies was related to improved survival warranting further investigation of bone biomarkers as predictors of cabazitaxel efficacy. Micro-AbstactCabaBone is a phase II translational study that evaluated the role of bone microenvironment and HRR genes mutations in the efficacy of cabazitaxel in mCRPC patients with bone-only disease. Study confirmed efficacy of cabazitaxel in patients independent of the presence of HRR gene mutations. Reactive hematopoiesis in bone marrow was recognized as a possible predictive and prognostic biomarker of cabazitaxel efficacy.