After Androgen Deprivation Therapy Research Articles

Cardiovascular risk of gonadotropin-releasing hormone antagonist versus agonist in men with prostate cancer: an observational study in Taiwan

BackgroundThe impact of gonadotropin-releasing hormone (GnRH) antagonist and agonist (GnRHa) treatment on cardiovascular disease (CVD) risk in prostate cancer (PCa) remains inconclusive due to conflicting findings. We compared the effects of GnRH antagonist and GnRHa treatments on CVD risk in patients with PCa and pre-existing CVD, in a Taiwan population-based database.MethodsWe assessed the risk of major adverse CV events (MACE: ischemic heart disease [IHD], stroke, congestive heart failure [CHF] or all cause deaths) and composite CV events (IHD, stroke, CHF or CV deaths) occurring ≥90 days after androgen deprivation therapy (ADT) initiation in patients with PCa after 90 days of treatment with either GnRH antagonist (degarelix; n = 499) or GnRHa (goserelin, leuprolide, triptorelin; n = 15,127). Patients identified with pre-existing CVD had received cardiac therapy for IHD, reported a stroke or CHF within a year before ADT initiation. Adjusted hazard ratios (aHR) and 95% confidence interval (CI) were obtained for MACE and composite CV events risk after adjusting for age, baseline status of diabetes, hypertension and treatments received.ResultsAll GnRH antagonist-treated patients showed lower risk of composite CV events than the GnRHa-treated patients. The lower composite CV events risk associated with GnRH antagonist was also observed in patients with metastasis at diagnosis (aHR 0.16; 95% CI, 0.04–0.38; p = 0.013) and those receiving ADT for more than six months (aHR 0.30; 95% CI, 0.16–0.54; p < 0.0001). In patients with pre-existing CVD, the MACE risk was 33% lower (aHR 0.67; 95% CI, 0.46–0.96; p = 0.0299) and composite CV events risk was 84% lower (aHR 0.16; 95% CI, 0.05–0.50; p = 0.0017) in GnRH antagonist-treated than the GnRHa-treated patients.ConclusionsIn patients with PCa and pre-existing CVD, GnRH antagonist use was associated with lower risks for composite CV events and MACE compared with GnRHa.

Pre-existing Castration-resistant Prostate Cancer–like Cells in Primary Prostate Cancer Promote Resistance to Hormonal Therapy

BackgroundHormonal therapy targeting the androgen receptor inhibits prostate cancer (PCa), but the tumor eventually recurs as castration-resistant prostate cancer (CRPC). ObjectiveTo understand the mechanisms by which subclones within early PCa develop into CRPC. Design, setting, and participantsWe isolated epithelial cells from fresh human PCa cases, including primary adenocarcinoma, locally recurrent CRPC, and metastatic CRPC, and utilized single-cell RNA sequencing to identify subpopulations destined to become either CRPC-adeno or small cell neuroendocrine carcinoma (SCNC). Outcome measurements and statistical analysisWe revealed dynamic transcriptional reprogramming that promotes disease progression among 23226 epithelial cells using single-cell RNA sequencing, and validated subset-specific progression using immunohistochemistry and large cohorts of publically available genomic data. Results and limitationsWe identified a small fraction of highly plastic CRPC-like cells in hormone-naïve early PCa and demonstrated its correlation with biochemical recurrence and distant metastasis, independent of clinical characteristics. We show that progression toward castration resistance was initiated from subtype-specific lineage plasticity and clonal expansion of pre-existing neuroendocrine and CRPC-like cells in early PCa. ConclusionsCRPC-like cells are present early in the development of PCa and are not exclusively the result of acquired evolutionary selection during androgen deprivation therapy. The lethal CRPC and SCNC phenotypes should be targeted earlier in the disease course of patients with PCa. Patient summaryHere, we report the presence of pre-existing castration-resistant prostate cancer (CRPC)-like cells in primary prostate cancer, which represents a novel castration-resistant mechanism different from the adaptation mechanism after androgen deprivation therapy (ADT). Patients whose tumors harbor increased pre-existing neuroendocrine and CRPC-like cells may become rapidly resistant to ADT and may require aggressive early intervention.

Targeting Inflammatory Signaling in Prostate Cancer Castration Resistance.

Although castration-resistant prostate cancer (CRPC) as a whole, by its name, refers to the tumors that relapse and/or regrow independently of androgen after androgen deprivation therapy (ADT), untreated tumor, even in early-stage primary prostate cancer (PCa), contains androgen-independent (AI) PCa cells. The transformation of androgen-dependent (AD) PCa to AI PCa under ADT is a forced evolutionary process, in which the small group of AI PCa cells that exist in primary tumors has the unique opportunity to proliferate and expand selectively and dominantly, while some AD PCa cells that have escaped from ADT-induced death acquire the capability to survive in an androgen-depleted environment. The adaptation and reprogramming of both PCa cells and the tumor microenvironment (TME) under ADT make PCa much stronger than primary tumors so that, currently, there are no effective therapeutic methods available for the treatment of CRPC. Many mechanisms have been found to be related to the emergence and maintenance of PCa castration resistance; in this review, we focus on the role of inflammatory signaling in both PCa cells and the TME for the emergence and maintenance of CRPC and summarize the recent advances of therapeutic strategies that target inflammatory signaling for the treatment of CRPC.

Prostate cancer castrate resistant progression usage of non-canonical androgen receptor signaling and ketone body fuel

Prostate cancer (PCa) that progresses after androgen deprivation therapy (ADT) remains incurable. The underlying mechanisms that account for the ultimate emergence of resistance to ADT, progressing to castrate-resistant prostate cancer (CRPC), include those that reactivate androgen receptor (AR), or those that are entirely independent or cooperate with androgen signaling to underlie PCa progression. The intricacy of metabolic pathways associated with PCa progression spurred us to develop a metabolism-centric analysis to assess the metabolic shift occurring in PCa that progresses with low AR expression. We used PCa patient-derived xenografts (PDXs) to assess the metabolic changes after castration of tumor-bearing mice and subsequently confirmed main findings in human donor tumor that progressed after ADT. We found that relapsed tumors had a significant increase in fatty acids and ketone body (KB) content compared with baseline. We confirmed that critical ketolytic enzymes (ACAT1, OXCT1, BDH1) were dysregulated after castrate-resistant progression. Further, these enzymes are increased in the human donor tissue after progressing to ADT. In an in silico approach, increased ACAT1, OXCT1, BDH1 expression was also observed for a subset of PCa patients that relapsed with low AR and ERG (ETS-related gene) expression. Further, expression of these factors was also associated with decreased time to biochemical relapse and decreased progression-free survival. Our studies reveal the key metabolites fueling castration resistant progression in the context of a partial or complete loss of AR dependence.

Association between Androgen Deprivation Therapy and Risk of Dementia in Men with Prostate Cancer.

Simple SummaryAndrogen deprivation therapy (ADT) is the gold standard treatment for advanced prostate cancer and the subsequent risk of dementia remains controversial. Previous studies were limited by small sample sizes, short follow-up times, and racial differences. In this population-based cohort study, we used the National Health Insurance Database of Taiwan and The Health Improvement Network database of the United Kingdom to retrospectively study 129,126 men with prostate cancer in the United Kingdom (UK) and Taiwan. Compared with the ADT-naïve control, patients treated with ADT showed no significant increase in the risk of dementia in both the UK and Taiwan populations. Despite the differences in the populations of the two databases, these results suggest no association between the use of ADT and new-onset dementia.The risk of dementia after androgen deprivation therapy (ADT) in patients with advanced prostate cancer (PCa) remains controversial. This study aimed to evaluate the association between ADT and the incidence of dementia in patients with PCa. We identified patients newly diagnosed with PCa in the National Health Insurance Database of Taiwan from 1 January 2002 to 30 June 2016 and in The Health Improvement Network of the United Kingdom (UK) from 1 January 1998 to 31 March 2018. We classified patients with PCa into ADT and ADT-naïve groups. Propensity score (PS) methods were used to minimize the differences in characteristics between the groups. We performed a Cox proportional hazard model to obtain the adjusted hazard ratio (HR) to compare the incidence of dementia between the groups. Our ADT group comprised 8743 and 73,816 patients in Taiwan and the UK, respectively, which were matched 1:1 to ADT-naïve patients by PS. The incidence rates of dementia in the ADT group were 2.74 versus 3.03 per 1000 person-years in the ADT naïve groups in Taiwan, and 2.81 versus 2.79 per 1000 person-years in the UK. There was no statistical difference between ADT and ADT-naïve groups (adjusted HR: 1.12; 95% confidence interval (CI): 0.87–1.43 in Taiwan and adjusted HR: 1.02; 95% CI: 0.85–1.23 in the UK). We found no association between the incidence of dementia and ADT in patients with advanced PCa in either database. Further studies are warranted to evaluate other possible triggers of incident dementia in patients receiving ADT for advanced PCa.

Characterization of Novel Progression Factors in Castration-Resistant Prostate Cancer Based on Global Comparative Proteome Analysis.

Simple SummaryHere, we investigated prostate cancer (PCa) tissues at each stage of progression, from benign prostatic hyperplasia to castration-resistant prostate cancer (CRPC), based on quantitative proteomic technology, including tissues after androgen deprivation therapy (ADT). In total, we identified 4768 proteins, and 4069 of them were quantified. We performed a systematic bioinformatics analysis of 865 differentially expressed proteins (DEPs) in the combined PCa tissues. We found 15 DEPs, including FOXA1 and HMGN1–3, as novel factors were significantly involved in the progression to CRPC after ADT in T3G3. All targets were verified to have increased levels of FOXA1 and HMGN1–3 in CRPC by immunoblotting and indirect enzyme-linked immunosorbent assay. The FOXA1 and HMGN1–3 proteins could be used as CRPC-related factors in clinical therapeutic agents.Identifying the biological change from hormone-naïve prostate cancer to castration-resistant prostate cancer (CRPC) is a major clinical challenge for developing therapeutic agents. Although the pathways that lead to CRPC are not fully completely understood, recent evidence demonstrates that androgen signaling is often maintained through varied mechanisms. Androgen deprivation therapy (ADT) is used as a primary treatment for preventing the progression of prostate cancer (PCa). Here we investigated PCa tissues at each stage of progression, from benign prostatic hyperplasia (BPH) to CRPC, based on quantitative proteomic technology, including tissues after ADT. In total, 4768 proteins were identified in this study, of which 4069 were quantified in the combined PCa tissues. Among the quantified proteins, 865 were differentially expressed proteins (21.2%). Based on the quantitative protein results, we performed systematic bioinformatics analysis and found that the levels of 15 proteins, including FOXA1 and HMGN1–3, increased among T3G3, T3GX, and CRPC, despite the ADT. Among all targets, we verified the increased levels of FOXA1 and HMGN1–3 in CRPC by immunoblotting and indirect enzyme-linked immunosorbent assay. In summary, we discuss the changes in intracellular factors involved in the progression of CRPC PCa despite ADT. Moreover, we suggest that FOXA1 and HMGN1–3 proteins could be used as potential CRPC-related factors in clinical therapeutic agents.

Abstract 725: LIFR promotes SUCLG2-dependent castration resistance and neuroendocrine differentiation of prostate cancer

Abstract Neuroendocrine (NE) differentiation is a well-recognized phenotypic change of prostate cancer after androgen-deprivation therapy (ADT) that ultimately develops an aggressive subtype. An increasing number of patients with NE histologic type prostate cancer present with metabolic genes disorder. However, the metabolic pathways that influence the malignant transformation and the NE differentiation of prostate cancer remain unclear. In this study, we found that ADT induced the upregulation of leukemia inhibitory factor receptor (LIFR), which contributes to the expression of succinate-CoA ligase GDP-forming beta subunit (SUCLG2), thus activating metabolic reprogramming to enable NE differentiation and increase aggressiveness. Activated LIF-LIFR-STAT3 axis stimulates SUCLG2 expression, subsequently upregulating glucose metabolism and the NE differentiation of prostate cancer. SUCLG2 knockdown markedly reduced mitochondrial DNA content and inhibited the enzymatic activity of succinyl-CoA synthetase and nucleoside diphosphate kinase (NDPK) in prostate cancer cells. SUCLG2 overexpression promoted androgen-independent proliferation; however, SUCLG2 knockdown suppressed NE differentiation and the ADT resistance of prostate cancer cells. Analysis of prostate tissue samples showed an increased intensity of LIFR associated with SUCLG2 in castration-resistant prostate cancer tumors. Our study identifies SUCLG2 as a potential prognostic marker of ADT-resistant prostate cancer and suggests it could be a target for prostate cancer treatment. Citation Format: Hsiu-Lien Yeh, Shian-Ren Lin, Kuo-Ching Jiang, Wei-Hao Chen, Yen-Nien Liu. LIFR promotes SUCLG2-dependent castration resistance and neuroendocrine differentiation of prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 725.

Abstract 2346: Prostate cancer castrate resistant progression usage of non-canonical androgen receptor signaling and ketone body fuel

Abstract Prostate cancer (PCa) that progresses after androgen deprivation therapy (ADT) remains incurable. The intricacy of metabolic pathways associated with PCa progression spurred us to develop a metabolism-centric analysis. Using PCa patient-derived xenografts (PDXs) we assessed the metabolic changes after castration of tumor-bearing mice. We found that relapsed tumors had a significant increase in fatty acids and ketone body content compared with baseline. We confirmed that critical ketogenic/ketolytic enzymes (ACAT1, OXCT1, BDH1) were significantly augmented after castrate-resistant progression. Further, these enzymes are increased in the human donor tissue after progressing to ADT. Increased ACAT1 and OXCT1 was also observed for a subset of PCa patients that relapsed with low AR and ERG expression. These factors were associated with decreased biochemical relapse and progression free survival. In summary, our studies reveal the key metabolites fueling castration resistant progression in the context of a partial or complete loss of AR dependence. Citation Format: Estefania Labanca, Juan Bizzotto, Jun Yang, Pablo Sanchis, Peter Shepherd, Alejandra Paez, Valeria Antico-Arciuch, Nicolas Anselmino, Sofia Lage-Vickers, Anh Hoang, Mark Tituts, Eleni Efstathiou, Javier Cotignola, Christopher Logothetis, Elba Vazquez, Nora Navone, Geraldine Gueron. Prostate cancer castrate resistant progression usage of non-canonical androgen receptor signaling and ketone body fuel [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2346.

SQLE Mediates Metabolic Reprogramming to Promote LN Metastasis in Castration-Resistant Prostate Cancer.

BackgroundAlmost all metastatic hormone-sensitive prostate cancers (mHSPC) will develop into metastatic castration-resistant prostate cancer (mCRPC) after androgen deprivation therapy (ADT). The expression level of squalene monooxygenase (SQLE) is increased in CRPC cells and regulates cholesterol metabolism. This study verified the biological function and mechanisms of SQLE in CRPC.MethodsThe expression of SQLE in human prostate cancer cells was overexpressed or silenced and its efficacy on cell survival was determined by the MTS test. Energy metabolism phenotype test was evaluated by XF real-time ATP rate assay, XF cell mitochondrial stress test, XF glycolysis stress test and XF mito fuel flex test. Cell migration and invasion were evaluated by colony formation assays and transwell assays; the expression of mRNA and protein was assessed by RT-qPCR and Western blot, respectively. Moreover, BALB/c nude mice model was performed to evaluate the lymph node metastasis.ResultsIn our study, we found that the expression level of SQLE was significantly increased in bicalutamide-resistant-C4-2B cells compared to LNCaP cells. SQLE knockdown partly restored the sensitivity of drug-resistant cells to bicalutamide and reduced lymph node metastasis by inhibiting fatty acid oxidation in mitochondria. We also found that terbinafine, the specific inhibitor of SQLE, can enhance the sensitivity of prostate cancer cells to bicalutamide.ConclusionOur study revealed that SQLE is involved in the progression of castration resistance in CRPC through mediating metabolic reprogramming, presenting SQLE as a new target for the treatment of mCRPC.

The clinical guiding value of a radiomics model for androgen deprivation therapy for prostate cancer.

ObjectiveThree models were used to evaluate prostate cancer after androgen deprivation therapy (ADT) and to determine the value of detecting residual lesions after treatment.MethodsWe retrospectively analysed patients with prostate cancer who received ADT from January 2018 to June 2019. Patients were divided into ADT responder and ADT non-responder groups, and clinical risk factors were determined. Regions of interest were manually contoured on each slice on fat-saturated-T2-weighted imaging, and radiomic features were extracted. Uni- and multivariate logistic regression were used to establish radiomics, clinical and combined models.ResultsThere were 23 ADT non-responders and 20 ADT responders. In the clinical model, total prostate-specific antigen concentration and T stage were independent predictors of efficacy (area under the curve (AUC) = 0.774). The characteristics, MinIntensity and Correlation_ angle135_offset4 indicated an effective clinical model (AUC = 0.807). GLCMEntropy_ AllDirection_offset1_SD was the best feature to differentiate residual lesions from the central gland (CG) (Lesion-CG model, AUC = 0.955). Correlation_angle135_offset4, GLCMEntropy_ AllDirection_offset4_SD and GLCMEntropy_AllDirection_offset7_SD differentiated residual lesions from the peripheral zone (PZ) (Lesion-PZ model, AUC = 0.855). The AUC for the combined model was 0.904.ConclusionsOur models can guide the clinical treatment of patients with different ADT responses. Furthermore, the radiomics model can detect prostate cancer that is non-responsive to ADT.

Characteristics and comorbidities of veterans treated with enzalutamide or abiraterone.

e17022 Background: Prostate cancer (PCa) is the most common male malignancy and is the fourth leading cause of cancer-related death in males worldwide. Enzalutamide (ENZ) and Abiraterone (AA) are used in the treatment of castrate resistant PCa after androgen deprivation therapy (ADT), however these agents have not been directly compared. These drugs have various adverse effects with different mechanisms of action and may be selected based on comorbid conditions. In this study, we aim to identify patient characteristics and comorbidities of patients treated with ENZ versus AA. Methods: Patients treated with AA or ENZ between September 10, 2014 and June 3, 2017 were identified in the Veterans Health Administration and followed until April 2020. Only patients with a pathologic diagnosis of PCa and treatment with ADT prior to AA or ENZ were included. Age at initiation of treatment, Elixhauser comorbidity score, PSA at initiation of AA or ENZ, Gleason score at diagnosis, treatment with ADT, docetaxel, and cabazitaxel was collected. Months of filled prescriptions were used to determine length of treatment. Results: Of 2575 patients, 1095 (42.5%) were initially treated with ENZ, 1480 (57.5%) with AA, and 1330 (51.7%) received both agents. Overall, 756 (29.4%) of patients were of black race. Docetaxel was used in 32.3% of patients and cabazitaxel in 11.7% of patients, with no differences between ENZ or AA cohorts. There were no significant differences in time from pathologic diagnosis to initial ADT therapy, or subsequently to treatment with ENZ or AA in either group. Furthermore, there were no differences in PSA (n = 1243, median AA 33.7 vs ENZ 30.7, p = 0.538) or Gleason scores (n = 1816, mean AA 7.85 vs ENZ 7.94, p = 0.142). Patients initially treated with ENZ compared to AA were older (mean 74.2 vs. 73.7 years, p = 0.032), had higher mean comorbidity score (7.1 vs. 6.7, p = 0.002), and had a longer duration of first treatment (median 10.5 months vs. 9.0 months, p &lt; 0.001). As a second agent, ENZ also had a longer duration of treatment (median 5.0 vs. 4.2 months, p &lt; 0.001). Patients treated initially with ENZ were more likely to have heart failure (18.2% vs. 13.7%, p = 0.002), cardiac arrhythmia (42.1% vs 36.6%, p = 0.004), valvular disease (13.7% vs 10.3%, p = 0.009), peripheral vascular disorders (26.8% vs 22.7%, p = 0.016), uncomplicated hypertension (86.8% vs 83.6%, p = 0.024), complicated hypertension (20.2% vs 16.9%, p = 0.033), uncomplicated diabetes (43.9% vs 37.4%, p = 0.001), complicated diabetes (26.0% vs 19.9%, p = 0.000), renal failure (28.3% vs 22.6%, p = 0.001). Conclusions: Overall, we found that patients initially treated with ENZ were older and had higher rates of cardiovascular disease and diabetes compared to those initially treated with AA. Assessment of comorbidities may be helpful in treatment selection to facilitate personalized medicine in prostate cancer, prevent adverse events, and improve outcomes.

High Monocyte Count and Expression of S100A9 and S100A12 in Peripheral Blood Mononuclear Cells Are Associated with Poor Outcome in Patients with Metastatic Prostate Cancer.

Simple SummaryProstate tumors are heterogeneous with unpredictable outcomes, ranging from harmless to aggressive, metastatic and deadly disease. Current diagnostic methods have limited ability to predict disease aggressiveness. New biomarkers are urgently needed to improve risk stratification, preferably involving non-invasive procedures. The aim of this prospective study was to assess the prognostic value of the inflammation markers S100A9 and S100A12 together with the monocyte count in blood samples from a cohort of 121 prostate cancer patients. We show that high monocyte count and high mRNA levels of S100A9, S100A12 are associated with poor outcome in patients with metastases at diagnosis. Our results suggest that analysis of these factors in blood could identify patients who are in direct need of additional treatment to conventional androgen deprivation therapy (ADT).Increasing evidence indicates calcium-binding S100 protein involvement in inflammation and tumor progression. In this prospective study, we evaluated the mRNA levels of two members of this family, S100A9 and S100A12, in peripheral blood mononuclear cells (PBMCs) in a cohort of 121 prostate cancer patients using RT-PCR. Furthermore, monocyte count was determined by flow cytometry. By stratifying patients into different risk groups, according to TNM stage, Gleason score and PSA concentration at diagnosis, expression of S100A9 and S100A12 was found to be significantly higher in patients with metastases compared to patients without clinically detectable metastases. In line with this, we observed that the protein levels of S100A9 and S100A12 in plasma were higher in patients with advanced disease. Importantly, in patients with metastases at diagnosis, high monocyte count and high levels of S100A9 and S100A12 were significantly associated with short progression free survival (PFS) after androgen deprivation therapy (ADT). High monocyte count and S100A9 levels were also associated with short cancer-specific survival, with monocyte count providing independent prognostic information. These findings indicate that circulating levels of monocytes, as well as S100A9 and S100A12, could be biomarkers for metastatic prostate cancer associated with particularly poor prognosis.

High Serum Alkaline Phosphatase Flare after First-Line Androgen Deprivation Therapy Predicts Poor Prognosis in Metastatic Prostate Cancer Patients Treated with Second-Generation Androgen Receptor Targeted Therapy.

Objectives To determine whether an alkaline phosphatase (ALP) flare after androgen deprivation therapy (ADT) is associated with the treatment response in castration-resistant prostate cancer (CRPC) and predicts the prognosis of metastatic prostate cancer (PCa) patients. Methods One hundred and nineteen patients diagnosed with metastatic PCa between 2008 and 2017 were retrospectively studied. The ALP flare ratio was calculated as the ratio of ALP levels 1 month after beginning ADT to ALP levels at diagnosis. The association of the ALP flare ratio with the prostate-specific antigen (PSA) response to CRPC treatment (second-generation androgen receptor targeted therapy (ART) or docetaxel), time to CRPC, and overall survival (OS) were investigated. Results The time to CRPC and OS was significantly longer in patients with an ALP flare ratio less than 1.33 compared to a ratio more than 1.33. No difference in PSA response was seen regarding the ALP flare ratio in both ART and docetaxel treatment. Second-generation ART-treated patients with a low ALP flare ratio showed longer OS than those with a higher ALP flare ratio (p=0.0367). However, no difference was seen between a high and low ALP flare ratio (p=0.8054) in docetaxel-treated patients. The ALP flare ratio was the most significant prognostic factor for OS (p < 0.0001). Conclusions A higher ALP flare ratio after first-line ADT was a significant prognostic factor in metastatic PCa, especially in patients treated with second-generation ART for CRPC. Chemotherapy for patients with a higher ALP flare ratio 1 month after induction of ADT may be a clinically relevant decision.

Phage display screening identifies a prostate specific antigen (PSA)–/lo prostate cancer cell specific peptide to retard castration resistance of prostate cancer

Patients with prostate cancer (PCa) will eventually progress to castrate-resistant prostate cancer (CRPC) after androgen deprivation therapy (ADT) treatment. Prostate-specific antigen (PSA)−/lo cells which harbor self-renewing long-term tumor-propagating cells that can be enriched using ALDH+CD44+α2β1+ and can initiate tumor development may represent a critical source of CRPC cells. Our purpose was to find a peptide that specifically targets PSA−/lo PCa cells to retard the development of CRPC. PSA+ and PSA−/lo cells were successfully separated from LNCaP xenograft tumors after prostate- PSAP-GFP vector infection and FACS. A variety of PSA−/lo cells specifically targeting peptide (named as “TAP1” targeted affinity peptide 1) was identified by using phage display library screening. The highest binding rate in TAP1 binding cell subpopulations are identified to be among ALDH+CD44+CXCR4+CD24+ cells. TAP1 significantly inhibited PCa growth both in vitro and in vivo. TAP1 significantly improved the anti-proliferation effect of the anti-androgens (Charcoal dextran-stripped serum (CDSS)+Bicalutamide, Enzalutamide) and chemotherapeutic agents (Abiraterone, Docetaxel, Etoposide) in vitro. TAP1 treatment shortens the length of telomeres in ALDH+CD44+CXCR4+CD24+ cells and significantly reduces the expression of Homeobox B9 (HOXB9) and TGF-β2. In conclusion, PSA−/lo PCa cell-specific targeting peptide (TAP1) that suppressed PCa cell growth both in vitro and in vivo and improved the drug sensitivities of anti-androgens and chemotherapeutic agents at least through shortening the length of telomere and reducing the expression of HOXB9 and TGF-β2. Therapeutic peptides that specifically target prostate cancer stem cell might be a very valuable and promising approach to overcome chemoresistance and prevent recurrence in patients with PCa.

Loss of EHF facilitates the development of treatment-induced neuroendocrine prostate cancer

The rising of a highly aggressive subtype of castration-resistant prostate cancer (CRPC) named treatment-induced neuroendocrine prostate cancer (t-NEPC) after androgen deprivation therapy (ADT) is well known for its features of the neuroendocrine differentiation (NED) and androgen receptor (AR) independence. However, t-NEPC is still largely unknown. Here, we found that EHF is notably depressed in t-NEPC tumors, patient-derived xenografts, transgenic mice, and cell models. Results from cell lines uncovered that ADT represses EHF expression, which is required for the ADT-induced NED. Mechanism dissection revealed that ADT decreases the EHF transcription via relieving the AR binding to different androgen-responsive elements, which then promotes the expression and enzymatic activity of enhancer of zeste homolog 2 (EZH2), consequently catalyzing tri-methylation lysine 27 of histone H3 for transcriptional repression of its downstream genes to promote the NED. Furthermore, preclinical studies from cell and mice models proved that recovery of EHF expression or using EZH2 inhibitor can attenuate aggressive properties of CRPC cells, hinder the progression of t-NEPC, and promote the response of CPRC cells to enzalutamide. Together, we elucidate that the ADT/AR/EHF/EZH2 signaling is required for the ADT-enhanced NED and plays a critical role in the progression of t-NEPC.

Nomogram Incorporating Contrast-Enhanced Ultrasonography Predicting Time to the Development of Castration-Resistant Prostate Cancer.

Background:It is valuable to predict the time to the development of castration-resistant prostate cancer (CRPC) in patients with advanced prostate cancer (PCa). This study aimed to build and validate a nomogram incorporating the clinicopathologic characteristics and the parameters of contrast-enhanced ultrasonography (CEUS) to predict the time to CRPC after androgen deprivation therapy (ADT).Methods:Patients with PCa were divided into the training (n = 183) and validation cohorts (n = 37) for nomogram construction and validation. The clinicopathologic characteristics and CEUS parameters were analyzed to determine the independent prognosis factors and serve as the basis of the nomogram to estimate the risk of 1-, 2-, and 3-year progress to CRPC.Results:T stage, distant metastasis, Gleason score, area under the curve (AUC), prostate-specific antigen (PSA) nadir, and time to PSA nadir were the independent predictors of CRPC (all P < 0.05). Three nomograms were built to predict the time to CRPC. Owing to the inclusion of CEUS parameter, the discrimination of the established nomogram (C-index: 0.825 and 0.797 for training and validation datasets) was improved compared with the traditional prediction model (C-index: 0.825 and 0.797), and when it excluded posttreatment PSA, it still obtained an acceptable discrimination (C-index: 0.825 and 0.797).Conclusions:The established nomogram including regular prognostic indicators and CEUS obtained an improved accuracy for the prediction of the time to CRPC. It was also applicable for early prediction of CRPC when it excluded posttreatment PSA, which might be helpful for individualized diagnosis and treatment.

Role of SPTSSB-Regulated de Novo Sphingolipid Synthesis in Prostate Cancer Depends on Androgen Receptor Signaling.

SummaryAnti-androgens are a common therapy in prostate cancer (PCa) targeting androgen receptor (AR) signaling. However, these therapies fail due to selection of highly aggressive AR-negative cancer cells that have no therapeutic options available. We demonstrate that elevating endogenous ceramide levels with administration of exogenous ceramide nanoliposomes (CNLs) was efficacious in AR-negative cell lines with limited efficacy in AR-positive cells. This effect is mediated through reduced de novo sphingolipid synthesis in AR-positive cells. We show that anti-androgens elevate de novo generation of sphingolipids via SPTSSB, a rate-limiting mediator of sphingolipid generation. Moreover, pharmacological inhibition of AR increases the efficacy of CNL in AR-positive cells through de novo synthesis, while SPTSSB knockdown limited CNL's efficacy in AR-negative cells. Alluding to clinical relevance, SPTSSB is upregulated in patients with advanced PCa after anti-androgens treatment. These findings emphasize the relevance of AR regulation upon sphingolipid metabolism and the potential of CNL as a PCa therapeutic.

EGFR-upregulated LIFR promotes SUCLG2-dependent castration resistance and neuroendocrine differentiation of prostate cancer.

Neuroendocrine (NE) differentiation is a well-recognized phenotypic change of prostate cancer after androgen deprivation therapy (ADT), and it ultimately develops into an aggressive subset of this disease. However, the contribution of signaling pathways that lead to metabolic disorders and NE differentiation of prostate cancer remains unclear. In this study, we identified that ADT induced upregulation of the succinate-CoA ligase GDP-forming beta subunit (SUCLG2), which regulates succinate metabolism and NE differentiation of prostate cancer. We demonstrated a connection that upregulation of epidermal growth factor receptor (EGFR)-leukemia inhibitory factor receptor (LIFR) signaling induced SUCLG2 expression in prostate cancer cells. The LIFR is upregulated by nuclear EGFR, which acts as a transcriptional regulator, directly binds to the LIFR promoter, and drives NE differentiation and glycolysis of prostate cancer. LIFR upregulation is associated with SUCLG2, which increased succinate synthesis and enzymatic activities of mitochondrial nucleoside diphosphate kinase (NDPK) in prostate cancer cells. Knockdown of SUCLG2 suppressed NE differentiation in cultured cells and reduced prostate tumor growth in a xenograft model. Analysis of prostate tissue samples showed increased intensity of nuclear EGFR associated with the LIFR and SUCLG2 in castration-resistant prostate cancer tumors. Our study provides a mechanism whereby ADT upregulates EGFR-LIFR signaling that activates SUCLG2, which subsequently stimulates the metabolic changes associated with NE differentiation and aggressive prostate cancer phenotype.

Crosstalk Between AR and Wnt Signaling Promotes Castration-Resistant Prostate Cancer Growth.

IntroductionProstate cancer (PCa) is the most commonly diagnosed cancer and the third leading cause of cancer-related death in males in the United States. Despite the initial efficacy of androgen deprivation therapy in prostate cancer (PCa) patients, most patients progress to castration-resistant prostate cancer. However, the mechanisms underlying the androgen-independent progression of PCa remain largely unknown.MethodsIn this study, we established a PCa cell line (LNCaP-AI) by maintaining LNCaP cells under androgen-depleted conditions. To explore the cellular and molecular mechanisms of androgen-independent growth of PCa, we analyzed the gene expression patterns in androgen-independent prostate cancer (AIPC) compared with that in androgen-dependent prostate cancer (ADPC). KEGG pathway analysis revealed that Wnt signaling pathways were activated after androgen deprivation therapy (ADT). In vitro experiments showed that the inhibition of Wnt pathway reduced AIPC cell growth by inhibiting cell cycle progression and promoting apoptosis. Furthermore, WNT5A, LEF1 were identified as direct targets of AR by chromatin immunoprecipitation (ChIP) assay and public ChIP-seq datasets analysis.ResultsIn the present study, we found a regulatory mechanism through which crosstalk between androgen receptor (AR) and Wnt signals promoted androgen-independent conversion of PCa. The Wnt pathway was inhibited by androgen in androgen-dependent prostate cancer cells, but this blocking effect was not elicited in androgen-independent prostate cancer (AIPC) cells. Moreover, Wnt pathway genes WNT5A and LEF1 were directly downregulated by AR. In vitro experiments showed that inhibition of the Wnt pathways repressed AIPC cell growth by inhibiting cell cycle progression and promoting apoptosis. We found that WNT5A and LEF1 were downregulated in low-grade PCa but upregulated in metastatic PCa.ConclusionIn summary, we revealed that crosstalk between AR and Wnt signaling pathways promotes androgen-independent growth of PCa, which may provide novel therapeutic opportunities for castration-resistant prostate cancer.

An artificial intelligence-enabled analysis of ECG changes after androgen deprivation therapy (ADT) for prostate cancer.

e17535 Background: Androgen Deprivation Therapy (ADT) is commonly used to treat prostate cancer (PC), but has been associated with cardiac morbidity and mortality. The exact mechanisms of this association are unclear. We sought to use an artificial intelligence (AI) enabled algorithm to identify ECG changes in PC patients who received ADT compared to PC patients who did not receive ADT. Methods: From 1,000,000 ECGs performed on 210,414 patients between 1993 and 2017 at our institution, a convolutional neural network was developed to detect predictive signatures for cardiac pathologies. During this process, the ability to predict “estimated sex” of the patient was developed, with output values ranging from 0 (female) to 1 (male). We applied this algorithm to 8,619 ECGs performed on 1,057 men age 75 or younger treated with radiation for high-risk or recurrent PC at our institution, and compared estimated sex after receiving ADT (n = 1,065) to ADT-naive ECGs (n = 7,554). We correlated ECG-identified estimated sex with serum testosterone levels using Spearman rank correlation. Results: Patients who had received ADT had a mean (SD) estimated sex value of 0.81 (0.26) compared to 0.92 (0.17) for those who did not (p &lt; 0.001). Difference between estimated sex in post-ADT ECGs and ADT-naive ECGs remained significant across age groups (Table). Decreased serum total testosterone correlated with decreased estimated sex values in men receiving ADT (R = .57, p &lt; 0.001). Conclusions: ADT for prostate cancer is associated with changes in AI-identified ECG parameters, including lower estimated male sex after receiving ADT. Lower ECG male sex estimate was associated with decreased serum testosterone. In this study, we provide preliminary proof of concept for a potential non-invasive means of monitoring treatment effect and physiologic change using ECGs. [Table: see text]