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Sample records for progressive castration-resistant prostate

  1. Targeting the androgen receptor pathway in castration-resistant prostate cancer: progresses and prospects

    PubMed Central

    Ferraldeschi, R; Welti, J; Luo, J; Attard, G; de Bono, JS

    2015-01-01

    Androgen receptor (AR) signaling is a critical pathway for prostate cancer cells, and androgen-deprivation therapy (ADT) remains the principal treatment for patients with locally advanced and metastatic disease. However, over time, most tumors become resistant to ADT. The view of castration-resistant prostate cancer (CRPC) has changed dramatically in the last several years. Progress in understanding the disease biology and mechanisms of castration resistance led to significant advancements and to paradigm shift in the treatment. Accumulating evidence showed that prostate cancers develop adaptive mechanisms for maintaining AR signaling to allow for survival and further evolution. The aim of this review is to summarize molecular mechanisms of castration resistance and provide an update in the development of novel agents and strategies to more effectively target the AR signaling pathway. PMID:24837363

  2. Hsp90 inhibitor 17-AAG inhibits progression of LuCaP35 xenograft prostate tumors to castration resistance

    PubMed Central

    O’Malley, Katherine J.; Langmann, Gabrielle; Ai, Junkui; Ramos-Garcia, Raquel; Vessella, Robert L.; Wang, Zhou

    2011-01-01

    BACKGROUND Advanced prostate cancer is currently treated with androgen deprivation therapy (ADT). ADT initially results in tumor regression, however, all patients eventually relapse with castration-resistant prostate cancer. New approaches to delay the progression of prostate cancer to castration resistance are in desperate need. This study addresses whether targeting HSP90 regulation of androgen receptor (AR) can inhibit prostate cancer progression to castration resistance. METHODS The HSP90 inhibitor 17-AAG was injected intraperitoneally into nude mice bearing LuCaP35 xenograft tumors to determine the effect of HSP90 inhibition on prostate cancer progression to castration resistance and host survival. RESULTS Administration of 17-AAG maintained androgen-sensitivity, delayed the progression of LuCaP35 xenograft tumors to castration resistance and prolonged the survival of host. In addition, 17-AAG prevented nuclear localization of endogenous AR in LuCaP35 xenograft tumors in castrated nude mice. CONCLUSIONS Targeting Hsp90 or the mechanism by which HSP90 regulates androgen-independent AR nuclear localization and activation may lead to new approaches to prevent and/or treat castration-resistant prostate cancer. PMID:22161776

  3. Activation of GRP/GRP-R signaling contributes to castration-resistant prostate cancer progression

    PubMed Central

    Qiao, Jingbo; Grabowska, Magdalena M.; Forestier, Ingrid S.; Mirosevich, Janni; Case, Thomas C.; Chung, Dai H.; Cates, Justin M.M.; Matusik, Robert J.; Manning, H. Charles; Jin, Renjie

    2016-01-01

    Numerous studies indicate that androgen receptor splice variants (ARVs) play a critical role in the development of castration-resistant prostate cancer (CRPC), including the resistance to the new generation of inhibitors of androgen receptor (AR) action. Previously, we demonstrated that activation of NF-κB signaling increases ARVs expression in prostate cancer (PC) cells, thereby promoting progression to CRPC. However, it is unclear how NF-κB signaling is activated in CRPC. In this study, we report that long-term treatment with anti-androgens increases a neuroendocrine (NE) hormone — gastrin-releasing peptide (GRP) and its receptor (GRP-R) expression in PC cells. In addition, activation of GRP/GRP-R signaling increases ARVs expression through activating NF-κB signaling. This results in an androgen-dependent tumor progressing to a castrate resistant tumor. The knock-down of AR-V7 restores sensitivity to antiandrogens of PC cells over-expressing the GRP/GRP-R signaling pathway. These findings strongly indicate that the axis of Androgen-Deprivation Therapy (ADT) induces GRP/GRP-R activity, activation NF-κB and increased levels of AR-V7 expression resulting in progression to CRPC. Both prostate adenocarcinoma and small cell NE prostate cancer express GRP-R. Since the GRP-R is clinically targetable by analogue-based approach, this provides a novel therapeutic approach to treat advanced CRPC. PMID:27542219

  4. Estrogen related receptor alpha in castration-resistant prostate cancer cells promotes tumor progression in bone

    PubMed Central

    Delliaux, Carine; Gervais, Manon; Kan, Casina; Benetollo, Claire; Pantano, Francesco; Vargas, Geoffrey; Bouazza, Lamia; Croset, Martine; Bala, Yohann; Leroy, Xavier; Rosol, Thomas J; Rieusset, Jennifer; Bellahcène, Akeila; Castronovo, Vincent; Aubin, Jane E; Clézardin, Philippe; Duterque-Coquillaud, Martine; Bonnelye, Edith

    2016-01-01

    Bone metastases are one of the main complications of prostate cancer and they are incurable. We investigated whether and how estrogen receptor-related receptor alpha (ERRα) is involved in bone tumor progression associated with advanced prostate cancer. By meta-analysis, we first found that ERRα expression is correlated with castration-resistant prostate cancer (CRPC), the hallmark of progressive disease. We then analyzed tumor cell progression and the associated signaling pathways in gain-of-function/loss-of-function CRPC models in vivo and in vitro. Increased levels of ERRα in tumor cells led to rapid tumor progression, with both bone destruction and formation, and direct impacts on osteoclasts and osteoblasts. VEGF-A, WNT5A and TGFβ1 were upregulated by ERRα in tumor cells and all of these factors also significantly and positively correlated with ERRα expression in CRPC patient specimens. Finally, high levels of ERRα in tumor cells stimulated the pro-metastatic factor periostin expression in the stroma, suggesting that ERRα regulates the tumor stromal cell microenvironment to enhance tumor progression. Taken together, our data demonstrate that ERRα is a regulator of CRPC cell progression in bone. Therefore, inhibiting ERRα may constitute a new therapeutic strategy for prostate cancer skeletal-related events. PMID:27776343

  5. The Interactions between Insulin and Androgens in Progression to Castrate-Resistant Prostate Cancer

    PubMed Central

    Gunter, Jennifer H.; Lubik, Amy A.; McKenzie, Ian; Pollak, Michael; Nelson, Colleen C.

    2012-01-01

    An association between the metabolic syndrome and reduced testosterone levels has been identified, and a specific inverse relationship between insulin and testosterone levels suggests that an important metabolic crosstalk exists between these two hormonal axes; however, the mechanisms by which insulin and androgens may be reciprocally regulated are not well described. Androgen-dependant gene pathways regulate the growth and maintenance of both normal and malignant prostate tissue, and androgen-deprivation therapy (ADT) in patients exploits this dependence when used to treat recurrent and metastatic prostate cancer resulting in tumour regression. A major systemic side effect of ADT includes induction of key features of the metabolic syndrome and the consistent feature of hyperinsulinaemia. Recent studies have specifically identified a correlation between elevated insulin and high-grade PCa and more rapid progression to castrate resistant disease. This paper examines the relationship between insulin and androgens in the context of prostate cancer progression. Prostate cancer patients present a promising cohort for the exploration of insulin stabilising agents as adjunct treatments for hormone deprivation or enhancers of chemosensitivity for treatment of advanced prostate cancer. PMID:22548055

  6. The hallmarks of castration-resistant prostate cancers.

    PubMed

    Katsogiannou, Maria; Ziouziou, Hajer; Karaki, Sara; Andrieu, Claudia; Henry de Villeneuve, Marie; Rocchi, Palma

    2015-07-01

    Prostate cancer has become a real public health issue in industrialized countries, mainly due to patients' relapse by castration-refractory disease after androgen ablation. Castration-resistant prostate cancer is an incurable and highly aggressive terminal stage of prostate cancer, seriously jeopardizing the patient's quality of life and lifespan. The management of castration-resistant prostate cancer is complex and has opened new fields of research during the last decade leading to an improved understanding of the biology of the disease and the development of new therapies. Most advanced tumors resistant to therapy still maintain the androgen receptor-pathway, which plays a central role for survival and growth of most castration-resistant prostate cancers. Many mechanisms induce the emergence of the castration resistant phenotype through this pathway. However some non-related AR pathways like neuroendocrine cells or overexpression of anti-apoptotic proteins like Hsp27 are described to be involved in CRPC progression. More recently, loss of expression of tumor suppressor gene, post-transcriptional modification using miRNA, epigenetic alterations, alternatif splicing and gene fusion became also hallmarks of castration-resistant prostate cancer. This review presents an up-to-date overview of the androgen receptor-related mechanisms as well as the latest evidence of the non-AR-related mechanisms underlying castration-resistant prostate cancer progression.

  7. Metastasis initiating cells in primary prostate cancer tissues from transurethral resection of the prostate (TURP) predicts castration-resistant progression and survival of prostate cancer patients.

    PubMed

    Li, Qinlong; Li, Quanlin; Nuccio, Jill; Liu, Chunyan; Duan, Peng; Wang, Ruoxiang; Jones, Lawrence W; Chung, Leland W K; Zhau, Haiyen E

    2015-09-01

    We previously reported that the activation of RANK and c-Met signaling components in both experimental mouse models and human prostate cancer (PC) specimens predicts bone metastatic potential and PC patient survival. This study addresses whether a population of metastasis-initiating cells (MICs) known to express a stronger RANKL, phosphorylated c-Met (p-c-Met), and neuropilin-1 (NRP1) signaling network than bystander or dormant cells (BDCs) can be detected in PC tissues from patients subjected to transurethral resection of the prostate (TURP) for urinary obstruction prior to the diagnosis of PC with or without prior hormonal manipulation, and whether the relative abundance of MICs over BDCs could predict castration-resistant progression and PC patient survival. We employed a multiplexed quantum-dot labeling (mQDL) protocol to detect and quantify MICs and BDCs at the single cell level in TURP tissues obtained from 44 PC patients with documented overall survival and castration resistance status. PC tissues with a higher number of MICs and an activated RANK signaling network, including increased expression of RANKL, p-c-Met, and NRP1 compared to BDCs, were found to correlate with the development of castration resistance and overall survival. The assessment of PC cells with MIC and BDC phenotypes in primary PC tissues from hormone-naïve patients can predict the progression to castration resistance and the overall survival of PC patients. © 2015 Wiley Periodicals, Inc.

  8. Metastasis Initiating Cells in Primary Prostate Cancer Tissues From Transurethral Resection of the Prostate (TURP) Predicts Castration-Resistant Progression and Survival of Prostate Cancer Patients

    PubMed Central

    Li, Qinlong; Li, Quanlin; Nuccio, Jill; Liu, Chunyan; Duan, Peng; Wang, Ruoxiang; Jones, Lawrence W.; Chung, Leland W. K.; Zhau, Haiyen E.

    2016-01-01

    BACKGROUND We previouslyreported that the activation of RANK and c-Met signaling components in both experimental mouse models and human prostate cancer (PC) specimens predicts bone metastatic potential and PC patient survival. This study addresses whether a population of metastasis-initiating cells (MICs) known to express a stronger RANKL, phosphorylated c-Met (p-c-Met), and neuropilin-1 (NRP1) signaling network than bystander or dormant cells (BDCs) can be detected in PC tissues from patients subjected to transurethral resection of the prostate (TURP) for urinary obstruction prior to the diagnosis of PC with or without prior hormonal manipulation, and whether the relative abundance of MICs over BDCs could predict castration-resistant progression and PC patient survival. METHODS We employed a multiplexed quantum-dot labeling (mQDL) protocol to detect and quantify MICs and BDCs at the single cell level in TURP tissues obtained from 44 PC patients with documented overall survival and castration resistance status. RESULTS PC tissues with a higher number of MICs and an activated RANK signaling network, including increased expression of RANKL, p-c-Met, and NRP1 compared to BDCs, were found to correlate with the development of castration resistance and overall survival. CONCLUSIONS The assessment of PC cells with MIC and BDC phenotypes in primary PC tissues from hormone-naïve patients can predict the progression to castration resistance and the overall survival of PC patients. PMID:25990623

  9. Olaparib With or Without Cediranib in Treating Patients With Metastatic Castration-Resistant Prostate Cancer

    ClinicalTrials.gov

    2017-09-12

    Castration Levels of Testosterone; Castration-Resistant Prostate Carcinoma; Metastatic Prostate Carcinoma; Prostate Adenocarcinoma With Focal Neuroendocrine Differentiation; Prostate Carcinoma Metastatic in the Bone; Prostate Small Cell Carcinoma; PSA Progression; Stage IV Prostate Adenocarcinoma

  10. Recent advances in the therapy of castration-resistant prostate cancer: the price of progress.

    PubMed

    Vasani, Dhwanishiva; Josephson, David Y; Carmichael, Courtney; Sartor, Oliver; Pal, Sumanta Kumar

    2011-10-01

    Within the past two years, three agents have garnered approval from the US FDA for the specific treatment of metastatic castration resistant prostate cancer (mCRPC) - (1) abiraterone, (2) cabazitaxel and (3) sipuleucel-T. In separate phase III studies, each agent led to an improvement in overall survival (OS) of 2-4 months over a suitable comparator. With these costly therapies all having potential application in the patient with mCRPC, multiple entities (industry, government, and the general public) must strategize to determine how the cost burden of these agents can be balanced with the potential gains for the individual patient. Herein, we provide a framework with which to approach this dilemma. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  11. Targeting the androgen receptor in the management of castration-resistant prostate cancer: rationale, progress, and future directions

    PubMed Central

    Leibowitz–Amit, R.; Joshua, A.M.

    2012-01-01

    Since the year 2000, tremendous progress has been made in the understanding of castration-resistant prostate cancer (crpc), a disease state now recognized to retain androgen receptor (ar)—dependency in most cases. That understanding led to the rational design of novel therapeutic agents targeting hormonal pathways in metastatic crpc. Two new drugs—the CYP17 inhibitor abiraterone acetate and the potent ar antagonist enzalutamide—were recently shown to prolong overall survival after chemotherapy treatment in patients with metastatic disease, with the former agent also demonstrating impressive activity in the pre-chemotherapy setting. Other new drugs targeting the ar—as well as drugs targeting heat shock proteins that protect cytoplasmic ar from degradation—are currently undergoing clinical development. This review briefly describes the molecular mechanisms underlying castration resistance and hormonal dependence in prostate tumours and summarizes the current ongoing and completed clinical trials that are targeting hormonal pathways in metastatic crpc. Potential mechanisms of resistance to these novel hormonal agents are reviewed. Finally, future research directions, including questions about drug sequencing and combination, are discussed. PMID:23355790

  12. Novel Therapeutic Targets to Inhibit Tumor Microenvironment Induced Castration-resistant Prostate Cancer

    DTIC Science & Technology

    2015-10-01

    AWARD NUMBER: W81XWH-13-1-0163 TITLE: Novel Therapeutic Targets to Inhibit Tumor Microenvironment Induced Castration-resistant Prostate Cancer ...Castration-resistant Prostate Cancer 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Feng Yang, Ph.D. 5d. PROJECT NUMBER 5e. TASK...Annual Progress Report W81XWH-13-1-0163 Novel Therapeutic Targets to Inhibit Tumor Microenvironment Induced Castration-resistant Prostate Cancer

  13. UGT2B17 Expedites Progression of Castration-Resistant Prostate Cancers by Promoting Ligand-Independent AR Signaling.

    PubMed

    Li, Haolong; Xie, Ning; Chen, Ruiqi; Verreault, Mélanie; Fazli, Ladan; Gleave, Martin E; Barbier, Olivier; Dong, Xuesen

    2016-11-15

    Castration-resistant prostate cancer (CRPC) is characterized by a shift in androgen receptor (AR) signaling from androgen-dependent to androgen (ligand)-independent. UDP-glucuronosyltransferase 2B17 (UGT2B17) is a key enzyme that maintains androgen homeostasis by catabolizing AR agonists into inactive forms. Although enhanced UGT2B17 expression by antiandrogens has been reported in androgen-dependent prostate cancer, its roles in regulating AR signaling transformation and CRPC progression remain unknown. In this study, we show that higher UGT2B17 protein expression in prostate tumors is associated with higher Gleason score, metastasis, and CRPC progression. UGT2B17 expression and activity were higher in androgen-independent compared to androgen-dependent cell lines. UGT2B17 stimulated cancer cell proliferation, invasion, and xenograft progression to CRPC after prolonged androgen deprivation. Gene microarray analysis indicated that UGT2B17 suppressed androgen-dependent AR transcriptional activity and enhanced of ligand-independent transcriptional activity at genes associated with cell mitosis. These UGT2B17 actions were mainly mediated by activation of the c-Src kinase. In CRPC tumors, UGT2B17 expression was associated positively with c-Src activation. These results indicate that UGT2B17 expedites CRPC progression by enhancing ligand-independent AR signaling to activate cell mitosis in cancer cells. Cancer Res; 76(22); 6701-11. ©2016 AACR.

  14. [Predictive factor analysis of time to progression of castration-resistant prostate cancer after androgen deprivation therapy].

    PubMed

    Ji, G J; Huang, C; Song, G; Li, X S; Song, Y; Zhou, L Q

    2017-08-18

    To explore risk factors including prostate-specific antigen (PSA) kinetics for the prediction of castration-resistant prostate cancer (CRPC), and to build a practical model for predicting the progression to CRPC after androgen deprivation therapy (ADT) so as to facilitate clinicians in decision-making for prostate cancer patients receiving ADT. A total of 185 patients with prostate cancer who had received ADT as the primary therapy in Department of Urology of Peking University First Hospital from 2003 to 2014 were enrolled retrospectively. All the patients were diagnosed with prostate cancer via prostate biopsy and followed up every four weeks from the initiation of ADT. All the patients received ADT with luteinizing hormone-releasing hormone agonists (LHRH-A) or surgical castration accompanied with an antiandrogen (bicalutamide or flutamide, combined androgen blockade). The clinical information of the patients were collected including age, clinical TNM stage, Gleason score (GS), risk groups of prostate cancer, PSA at the initiation of ADT, PSA nadir after ADT, PSA decline velocity, and the time to PSA nadir. The end point of this study was the diagnosis of CRPC, which was based on the European Association of Urology (EAU) Guideline 2016. Cox proportional hazards regression models were established to analyze and estimate their effects on the time of progression to CRPC. In this study, 185 patients with prostate cancer who had received ADT as the primary therapy were included. The mean age was (71.02±8.67) years. The median time to progression to CRPC in this cohort was 38 months (ranging from 4 to 158 months). On univariate analysis, we found clinical T stage, N stage, the metastasis state before ADT, risk groups of prostate cancer, PSA decline velocity, and PSA nadir were all related to the time to CRPC progression, P<0.01 for all the above variables. And on multivariate analysis, the presence of distant metastasis before ADT (HR=6.030, 95% CI: 3.229-11.263, P=0

  15. Nonmetastatic Castration-Resistant Prostate Cancer

    PubMed Central

    Hong, Jun Hyuk

    2014-01-01

    After the introduction of prostate cancer screening with the prostate-specific antigen (PSA) test, we have witnessed a dramatic stage migration. As a result, an increasing number of patients are diagnosed at earlier stages and receive local treatments including surgery or radiation. When these local treatments fail by the definition of increasing PSA levels, patients are usually treated with androgen-deprivation therapy. A fraction of these patients will finally reach a state of castration-resistant prostate cancer (CRPC) even without radiological evidence of metastasis, which is referred to as nonmetastatic CRPC (NM-CRPC). Most men with advanced or metastatic prostate cancer initially respond to various types of androgen ablation, but a considerable portion of them eventually progress to NM-CRPC. Among patients with NM-CPRC, about one-third will develop bone metastasis within 2 years. In these patients, PSA kinetics is the most powerful indicator of progression and is usually used to trigger further imaging studies and enrollment in clinical trials. Although CRPC remains largely driven by the androgen receptor, the benefit of second-line hormonal manipulations, including first-generation antiandrogens, adrenal synthesis inhibitors, and steroids, has not been investigated in men with NM-CRPC. To date, denosumab is the only agent that has been shown to delay the onset of bone metastasis. However, overall survival did not differ. In treating NM-CRPC patients, physicians should recognize the heterogeneity of the disease and acknowledge that the recently approved second-line treatments have been studied only in advanced stages of the disease. PMID:24648868

  16. Abiraterone Acetate and Castration Resistant Ductal Adenocarcinoma of the Prostate

    PubMed Central

    Linden-Castro, Edgar; Pelayo-Nieto, Marcela; Alias-Melgar, Alejandro; Espinosa-Perezgrovas, Daniel; Ramirez-Galindo, Ivan; Catalan-Quinto, Gabriel

    2014-01-01

    Ductal adenocarcinoma of the prostate is a rare histological variant that only represents <1% of prostate tumors. This histological variant has several important clinical implications with respect to their evolution, clinical prognosis, and treatment. We report the case of a 64-year-old patient with ductal adenocarcinoma of the prostate, which progresses to castration-resistant prostate cancer, that was treated with abiraterone acetate with good clinical response, to our knowledge, the first case of ductal adenocarcinoma of the prostate in treatment with abiraterone acetate. PMID:24891969

  17. Cotargeting Androgen Receptor and Clusterin Delays Castrate-Resistant Prostate Cancer Progression by Inhibiting Adaptive Stress Response and AR Stability.

    PubMed

    Matsumoto, Hiroaki; Yamamoto, Yoshiaki; Shiota, Masaki; Kuruma, Hidetoshi; Beraldi, Eliana; Matsuyama, Hideyasu; Zoubeidi, Amina; Gleave, Martin

    2013-08-15

    Although androgen receptor (AR) pathway inhibitors prolong survival in castrate-resistant prostate cancer (CRPC), resistance rapidly develops and is often associated with increased stress-activated molecular chaperones like clusterin (CLU) and continued AR signaling. Because adaptive pathways activated by treatment facilitate development of acquired resistance, cotargeting the stress response, activated by AR inhibition and mediated through CLU, may create conditional lethality and improve outcomes. Here, we report that CLU is induced by AR antagonism and silencing using MDV3100 and antisense, respectively, to become highly expressed in castrate- and MDV3100-resistant tumors and cell lines. CLU, as well as AKT and mitogen-activated protein kinase (MAPK) signalosomes, increase in response to MDV3100-induced stress. Mechanistically, this stress response is coordinated by a feed-forward loop involving p90rsk (RPS6KA)-mediated phosphoactivation of YB-1 with subsequent induction of CLU. CLU inhibition repressed MDV3100-induced activation of AKT and MAPK pathways. In addition, when combined with MDV3100, CLU knockdown accelerated AR degradation and repressed AR transcriptional activity through mechanisms involving decreased YB-1-regulated expression of the AR cochaperone, FKBP52. Cotargeting the AR (with MDV3100) and CLU (with OGX-011) synergistically enhanced apoptotic rates over that seen with MDV3100 or OGX-011 monotherapy and delayed CRPC LNCaP tumor and prostate-specific antigen (PSA) progression in vivo. These data indicate that cotargeting adaptive stress pathways activated by AR pathway inhibitors, and mediated through CLU, creates conditional lethality and provides mechanistic and preclinical proof-of-principle to guide biologically rational combinatorial clinical trial design.

  18. Understanding and Targeting Tumor Microenvironment in Prostate Cancer to Inhibit Tumor Progression and Castration Resistance

    DTIC Science & Technology

    2015-10-01

    SUBJECT TERMS Prostate cancer, myeloid-derived suppressor cell (MDSC), Pten, Smad4, genetically engineered mouse model, Gr-1, peptide-Fc fusion protein...KEYWORDS Prostate cancer, myeloid-derived suppressor cell (MDSC), Pten, Smad4, genetically engineered mouse model, Gr-1, peptide-Fc fusion protein 3...which should provide a genetic method for MDSC functional evaluation. Currently, the compound mouse Ptenpc-/- Smad4pc-/- CD11b-DTR+ are still in

  19. Castration-resistant prostate cancer: potential targets and therapies.

    PubMed

    Parray, Aijaz; Siddique, Hifzur R; Nanda, Sanjeev; Konety, Badrinath R; Saleem, Mohammad

    2012-01-01

    The treatment landscape for patients with castration-resistant prostate cancer (CRPC) is undergoing significant changes with the advent of new therapies and multidisciplinary efforts by scientists and clinicians. As activation of multiple molecular pathways in the neoplastic prostate makes it impossible for single-target drugs to be completely effective in treating CRPC, this has led to combination therapy strategy, where several molecules involved in tumor growth and disease progression are targeted by a therapeutic regimen. In the present review, we provide an update on the molecular pathways that play an important role in the pathogenesis of CRPC and discuss the current wave of new treatments to combat this lethal disease.

  20. Lipocalin 2 over-expression facilitates progress of castration-resistant prostate cancer via improving androgen receptor transcriptional activity

    PubMed Central

    Feng, Chenchen; Jiang, Haowen; Xu, Jianfeng; Ding, Qiang

    2016-01-01

    Background Castration-resistant prostate cancer (CRPC) is the lethal phenotype of prostate cancer. Lipocalin 2 (LCN2) is aberrantly expressed in many cancers including primary prostate cancer (PCa), but its role in CRPC has not been reported. Results LCN2 expression was upregulated in human primary PCa and CRPC tissues. Overexpression of LCN2 promoted C4-2B and 22RV1 cell proliferation while knockdown of LCN2 markedly inhibited C4-2B and 22RV1 cell growth. LCN2 overexpression led to increased AR downstream gene SLC45A3 without upregulating AR expression. In the xenograft model, overexpression of LCN2 significantly promoted tumor growth. Methods LCN2 expression was detected in primary PCa and CRPC tissues and cell lines C4-2B and 22RV1 using immunohistochemistry and western blotting, respectively. Serum LCN2 level was detected vi ELISA. Lentiviruses-mediated over-expression of LCN2 and LCN2 knockdown were performed in CRPC cell lines. Expressions of androgen receptor (AR) downstream genes was examined in cell lines, in CRPC tissues, and in animal models. Conclusion LCN2 could facilitate cell proliferation of CRPC via AR transcriptional activity. LCN2 could be a novel target in CRPC. PMID:27602760

  1. Castration-resistant prostate cancer: latest evidence and therapeutic implications

    PubMed Central

    Suzman, Daniel L.

    2014-01-01

    Medical oncologists who treat men with castration-resistant prostate cancer (CRPC) have seen an abundance of new agents approved by the United States Food and Drug Administration in the last decade for a disease that was previously difficult to treat after becoming resistant to androgen-deprivation therapy. Advances in understanding of the mechanisms of castration-resistance and prostate cancer progression have highlighted several pathways and targets that appear promising to better treat CRPC. As the majority of CRPC appears to continue to rely on the androgen receptor for growth and progression, several of these agents directly or indirectly target the androgen receptor. A novel microtubule-targeted agent, cabazitaxel, has demonstrated an overall survival benefit following progression on docetaxel. Other agents target tumor immunogenicity and immune checkpoint pathways to attempt to harness the host immune system. The recently approved radiopharmaceutical, radium-223 dichloride, has demonstrated impressive results in patients with extensive bony metastases with minimal toxicity. Lastly, further understanding of the pathways underlying CRPC progression has led to late-phase clinical trials with the novel agents: custirsen, tasquinimod and cabozantinib. This article reviews the approved therapies for CRPC, the agents currently in late-phase clinical trials, and notable early-phase trials of novel therapies and their combinations, with particular attention to trials incorporating novel biomarkers and intermediate endpoints to better identify those men who may or may not benefit from specific therapies. PMID:25057303

  2. Bone Scan Index and Progression-free Survival Data for Progressive Metastatic Castration-resistant Prostate Cancer Patients Who Received ODM-201 in the ARADES Multicentre Study.

    PubMed

    Reza, Mariana; Jones, Robert; Aspegren, John; Massard, Christophe; Mattila, Leena; Mustonen, Mika; Wollmer, Per; Trägårdh, Elin; Bondesson, Eva; Edenbrandt, Lars; Fizazi, Karim; Bjartell, Anders

    2016-12-01

    ODM-201, a new-generation androgen receptor inhibitor, has shown clinical efficacy in prostate cancer (PCa). Quantitative methods are needed to accurately assess changes in bone as a measurement of treatment response. The Bone Scan Index (BSI) reflects the percentage of skeletal mass a given tumour affects. To evaluate the predictive value of the BSI in metastatic castration-resistant PCa (mCRPC) patients undergoing treatment with ODM-201. From a total of 134 mCRPC patients who participated in the Activity and Safety of ODM-201 in Patients with Progressive Metastatic Castration-resistant Prostate Cancer clinical trial and received ODM-201, we retrospectively selected all those patients who had bone scan image data of sufficient quality to allow for both baseline and 12-wk follow-up BSI-assessments (n=47). We used the automated EXINI bone BSI software (EXINI Diagnostics AB, Lund, Sweden) to obtain BSI data. We used the Cox proportional hazards model and Kaplan-Meier estimates to investigate the association among BSI, traditional clinical parameters, disease progression, and radiographic progression-free survival (rPFS). In the BSI assessments, at follow-up, patients who had a decrease or at most a 20% increase from BSI baseline had a significantly longer time to progression in bone (median not reached vs 23 wk, hazard ratio [HR]: 0.20; 95% confidence interval [CI], 0.07-0.58; p=0.003) and rPFS (median: 50 wk vs 14 wk; HR: 0.35; 95% CI, 0.17-0.74; p=0.006) than those who had a BSI increase >20% during treatment. The on-treatment change in BSI was significantly associated with rPFS in mCRPC patients, and an increase >20% in BSI predicted reduced rPFS. BSI for quantification of bone metastases may be a valuable complementary method for evaluation of treatment response in mCRPC patients. An increase in Bone Scan Index (BSI) was associated with shorter time to disease progression in patients treated with ODM-201. BSI may be a valuable method of complementing treatment

  3. Abiraterone acetate for patients with metastatic castration-resistant prostate cancer progressing after chemotherapy: final analysis of a multicentre, open-label, early-access protocol trial.

    PubMed

    Sternberg, Cora N; Castellano, Daniel; Daugaard, Gedske; Géczi, Lajos; Hotte, Sebastien J; Mainwaring, Paul N; Saad, Fred; Souza, Ciro; Tay, Miah H; Garrido, José M Tello; Galli, Luca; Londhe, Anil; De Porre, Peter; Goon, Betty; Lee, Emma; McGowan, Tracy; Naini, Vahid; Todd, Mary B; Molina, Arturo; George, Daniel J

    2014-10-01

    In the final analysis of the phase 3 COU-AA-301 study, abiraterone acetate plus prednisone significantly prolonged overall survival compared with prednisone alone in patients with metastatic castration-resistant prostate cancer progressing after chemotherapy. Here, we present the final analysis of an early-access protocol trial that was initiated after completion of COU-AA-301 to enable worldwide preapproval access to abiraterone acetate in patients with metastatic castration-resistant prostate cancer progressing after chemotherapy. We did a multicentre, open-label, early-access protocol trial in 23 countries. We enrolled patients who had metastatic castration-resistant prostate cancer progressing after taxane chemotherapy. Participants received oral doses of abiraterone acetate (1000 mg daily) and prednisone (5 mg twice a day) in 28-day cycles until disease progression, development of sustained side-effects, or abiraterone acetate becoming available in the respective country. The primary outcome was the number of adverse events arising during study treatment and within 30 days of discontinuation. Efficacy measures (time to prostate-specific antigen [PSA] progression and time to clinical progression) were gathered to guide treatment decisions. We included in our analysis all patients who received at least one dose of abiraterone acetate. This study is registered with ClinicalTrials.gov, number NCT01217697. Between Nov 17, 2010, and Sept 30, 2013, 2314 patients were enrolled into the early-access protocol trial. Median follow-up was 5·7 months (IQR 3·5-10·6). 952 (41%) patients had a grade 3 or 4 treatment-related adverse event, and grade 3 or 4 serious adverse events were recorded in 585 (25%) people. The most common grade 3 and 4 adverse events were hepatotoxicity (188 [8%]), hypertension (99 [4%]), cardiac disorders (52 [2%]), osteoporosis (31 [1%]), hypokalaemia (28 [1%]), and fluid retention or oedema (23 [1%]). 172 (7%) patients discontinued the study

  4. Contributions of epithelial-mesenchymal transition and cancer stem cells to the development of castration resistance of prostate cancer

    PubMed Central

    2014-01-01

    An important clinical challenge in prostate cancer therapy is the inevitable transition from androgen-sensitive to castration-resistant and metastatic prostate cancer. Albeit the androgen receptor (AR) signaling axis has been targeted, the biological mechanism underlying the lethal event of androgen independence remains unclear. New emerging evidences indicate that epithelial-to-mesenchymal transition (EMT) and cancer stem cells (CSCs) play crucial roles during the development of castration-resistance and metastasis of prostate cancer. Notably, EMT may be a dynamic process. Castration can induce EMT that may enhance the stemness of CSCs, which in turn results in castration-resistance and metastasis. Reverse of EMT may attenuate the stemness of CSCs and inhibit castration-resistance and metastasis. These prospective approaches suggest that therapies target EMT and CSCs may cast a new light on the treatment of castration-resistant prostate cancer (CRPC) in the future. Here we review recent progress of EMT and CSCs in CRPC. PMID:24618337

  5. Castration-resistant prostate cancer: potential targets and therapies

    PubMed Central

    Parray, Aijaz; Siddique, Hifzur R; Nanda, Sanjeev; Konety, Badrinath R; Saleem, Mohammad

    2012-01-01

    The treatment landscape for patients with castration-resistant prostate cancer (CRPC) is undergoing significant changes with the advent of new therapies and multidisciplinary efforts by scientists and clinicians. As activation of multiple molecular pathways in the neoplastic prostate makes it impossible for single-target drugs to be completely effective in treating CRPC, this has led to combination therapy strategy, where several molecules involved in tumor growth and disease progression are targeted by a therapeutic regimen. In the present review, we provide an update on the molecular pathways that play an important role in the pathogenesis of CRPC and discuss the current wave of new treatments to combat this lethal disease. PMID:22956858

  6. A Novel Role for Raloxifene Nanomicelles in Management of Castrate Resistant Prostate Cancer

    PubMed Central

    Rosengren, Rhonda J.; Greish, Khaled

    2014-01-01

    Of patients with castrate resistant prostate cancer (CRPC), less than 25–33% survive more than five years. Recent studies have implicated estrogen, acting either alone or synergistically with androgens in the development of castrate resistant prostate cancer. Several in vitro and in vivo studies, as well as a limited number of clinical trials, have highlighted the potential of selective estrogen receptor modulators, such as raloxifene (Ral) for the treatment of castrate resistant prostate cancer. However, the poor oral bioavailability and metabolism of selective estrogen receptor modulators limit their efficiency in clinical application. To overcome these limitations, we have used styrene co-maleic acid (SMA) micelle to encapsulate raloxifene. Compared to free drug, SMA-Ral micelles had 132 and 140% higher cytotoxicity against PC3 and DU 145 prostate cell lines, respectively. SMA-Ral effectively inhibits cell cycle progression, increases apoptosis, and alters the integrity of tumor spheroid models. In addition, the micellar system induced changes in expression and localization of estrogen receptors, epidermal growth factor receptor (EGFR), and downstream effectors associated with cell proliferation and survival. Finally, SMA-Ral treatment decreased migration and invasion of castrate resistant prostate cancer cell lines. In conclusion, SMA-Ral micelles can potentially benefit new strategies for clinical management of castrate resistant prostate cancer. PMID:24689036

  7. Castration Resistance in Prostate Cancer Is Mediated by the Kinase NEK6. | Office of Cancer Genomics

    Cancer.gov

    In prostate cancer, the development of castration resistance is pivotal in progression to aggressive disease. However, understanding of the pathways involved remains incomplete. In this study, we performed a high-throughput genetic screen to identify kinases that enable tumor formation by androgen-dependent prostate epithelial (LHSR-AR) cells under androgen-deprived conditions.

  8. Management of castrate-resistant prostate cancer in older men.

    PubMed

    Ged, Yasser; Horgan, Anne M

    2016-03-01

    Prostate cancer is the most common cancer diagnosed in men with the highest incidence in older men. Older men are more likely to present with metastatic disease compared with younger patients and eventually all will develop castrate resistant disease. In recent years, a number of new treatment options have demonstrated survival benefits for metastatic castrate resistant prostate cancer. However, the lack of randomized trials directly comparing the different available options results in some uncertainty on how best to choose and sequence therapy. In this paper, we outline the therapeutic options available to men with metastatic castrate-resistant prostate cancer, including cytotoxic therapy, hormonal agents and bone-directed therapy. We focus particularly on the evidence for specific treatment options and the challenges faced in choosing the appropriate therapy for the older patient. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. [Evaluation and diagnosis for castration resistant prostate cancer: CRPC].

    PubMed

    Kamoto, Toshiyuki

    2014-12-01

    When considering the diagnosis of castration resistant prostate cancer (CRPC), one of the possible approaches consists of performing examination and diagnosis to determine the presence of CRPC. The definition of CRPC is simple-disease progression despite a serum testosterone value below 50 ng/dL after androgen deprivation therapy (ADT). It is similar to an earlier definition--"an initial relapse" occurring after primary ADT. Therefore, it is important to determine the histopathological type of CRPC to establish a course of treatment thereafter. Regarding the "examinations" and "diagnosis" for the staging of CRPC, it is likely that the circulating tumor cell assay and quantitative imaging examinations will be needed, instead of bone scintigraphy, in the future.

  10. Novel Therapies for Metastatic Castrate-Resistant Prostate Cancer

    PubMed Central

    Dayyani, Farshid; Gallick, Gary E.; Logothetis, Christopher J.

    2011-01-01

    Recent advances in tumor biology have made remarkable achievements in the development of therapy for metastatic castrate-resistant prostate cancer. These advances reflect a growing appreciation for the role of the tumor microenvironment in promoting prostate cancer progression. Prostate cancer is no longer viewed predominantly as a disease of abnormally proliferating epithelial cells but rather as a disease of complex interactions between prostate cancer epithelial cells (epithelial compartment) and the surrounding tissues (stromal compartment) in which they reside. For example, prostate cancers frequently metastasize to bone, an organ that contains a microenvironment rich in extracellular matrix proteins and stromal cells including hematopoietic cells, osteoblasts, osteoclasts fibroblasts, endothelial cells, adipocytes, immune cells, and mesenchymal stem cells. Multiple signaling pathways provide crosstalk between the epithelial and the stromal compartments to enhance tumor growth, including androgen receptor signaling, tyrosine kinase receptor signaling, and immune surveillance. The rationale to disrupt this “two-compartment” crosstalk has led to the development of drugs that target tumor stromal elements in addition to the cancer epithelial cell. PMID:21917607

  11. Molecular Indicators of Castration-Resistant Prostate Cancer

    DTIC Science & Technology

    2015-12-01

    implicated in castration resistance and enzalutamide resistance (note: due to Refseq sequence changes, the numbering of amino acid positions have...Regression of castrate-recurrent prostate cancer by a small-molecule inhibitor of the amino -terminus domain of the an- drogen receptor. Cancer Cell 2010;17

  12. Novel treatments for castration-resistant prostate cancer.

    PubMed

    Sternberg, Cora N

    2011-09-01

    The contemporary management of metastatic castration-resistant prostate cancer (mCRPC) is evolving dramatically. Understanding the biology of this disease, positive phase III studies and approvals for 4 novel agents in the US in 2010 and shortly in Europe have dramatically changed the therapeutic landscape. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Stilbenes inhibit androgen receptor expression in 22Rv1 castrate-resistant prostate cancer cells

    USDA-ARS?s Scientific Manuscript database

    Androgen receptor (AR) signaling plays an important role in the development and progression of prostate cancer (PCa). Importantly, AR continues to be expressed in advanced stages of castrate-resistant PCa (CRPC), where it can have ligand- independent activity. Identification of naturally occurring s...

  14. Prediction of PSA Progression in Castration-Resistant Prostate Cancer Based on Treatment-Associated Change in Tumor Burden Quantified by 18F-Fluorocholine PET/CT.

    PubMed

    Lee, Joohee; Sato, Miles M; Coel, Marc N; Lee, Kyung-Han; Kwee, Sandi A

    2016-07-01

    Measurements of metabolically active tumor volume (MATV) can be applied to (18)F-fluorocholine PET/CT to quantify whole-body tumor burden. This study evaluated the serial application of these measurements as systemic treatment response markers and predictors of disease progression in patients with castration-resistant prostate cancer (CRPC). Forty-two patients completed sequential (18)F-fluorocholine PET/CT scans before and 1-3 mo after starting treatment for CRPC. Whole-body tumor segmentation was applied to determine net MATV from each scan. Changes in net MATV were evaluated as predictors of time to prostate-specific antigen (PSA) progression by Kaplan-Meier and proportional hazards regression analysis. Treatments consisted of chemotherapy in 16 patients, antiandrogens in 19 patients, (223)Ra-dichloride in 5 patients, and sipuleucel-T in 2 patients. A significant MATV response (defined as a ≥30% decrease in net MATV) was observed in 20 patients on the basis of in-treatment PET/CT performed an average of 51 d (median, 49 d) into treatment. Significantly longer times to PSA progression were observed in patients who exhibited an MATV response (418 d vs. 116 d, P = 0.0067). MATV response was associated with a hazard ratio of 0.246 (P = 0.0113) for PSA progression, which remained significant when adjusted for treatment type. Significant changes in whole-body tumor burden can be measured on (18)F-fluorocholine PET/CT over the course of contemporary treatments for CRPC. In this study, these changes were found to be predictive of PSA progression as a potential surrogate marker of treatment outcome. Because (18)F-fluorocholine PET/CT can also be used for localizing resistant tumors, this modality can potentially complement other measures of response in the precision management of advanced prostate cancer. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  15. Targeting the MLL complex in castration resistant prostate cancer

    PubMed Central

    Malik, Rohit; Khan, Amjad P.; Asangani, Irfan A.; Cieślik, Marcin; Prensner, John R.; Wang, Xiaoju; Iyer, Matthew K.; Jiang, Xia; Borkin, Dmitry; Escara-Wilke, June; Stender, Rachell; Wu, Yi-Mi; Niknafs, Yashar S.; Jing, Xiaojun; Qiao, Yuanyuan; Palanisamy, Nallasivam; Kunju, Lakshmi P.; Krishnamurthy, Pranathi M.; Yocum, Anastasia K.; Mellacheruvu, Dattatreya; Nesvizhskii, Alexey I.; Cao, Xuhong; Dhanasekaran, Saravana M.; Feng, Felix Y.; Grembecka, Jolanta; Cierpicki, Tomasz; Chinnaiyan, Arul M.

    2015-01-01

    Resistance to androgen deprivation therapies and increased androgen receptor (AR) activity are major drivers of castration resistant prostate cancer (CRPC). Although prior work focused on targeting AR directly, co-activators of AR signaling—which may represent new therapeutic targets—are relatively underexplored. Here we demonstrate that the mixed-lineage leukemia (MLL) complex, a well-known driver of MLL-fusion-positive leukemia, acts as a co-activator of AR signaling. AR directly interacts with the MLL complex via the menin MLL subunit. Menin expression is higher in castration resistant prostate cancer compared to hormone naïve prostate cancer and benign prostate and high menin expression correlates with poor overall survival. Treatment with a small molecule inhibitor of the menin-MLL interaction blocks AR signaling and inhibits the growth of castration resistant tumors in vivo in mice. Taken together, this work identifies the MLL complex as a critical co-activator of AR and a potential therapeutic target in advanced prostate cancer. PMID:25822367

  16. Therapeutic vaccination with an interleukin-2-interferon-gamma-secreting allogeneic tumor vaccine in patients with progressive castration-resistant prostate cancer: a phase I/II trial.

    PubMed

    Brill, Thomas H; Kübler, Hubert R; Pohla, Heike; Buchner, Alexander; Fend, Falko; Schuster, Tibor; van Randenborgh, Heiner; Paul, Roger; Kummer, Tania; Plank, Christian; Eisele, Bernd; Breul, Jürgen; Hartung, Rudolf; Schendel, Dolores J; Gansbacher, Bernd

    2009-12-01

    Immunotherapy with whole cell cancer vaccines has been tested in various tumor types. This study investigated the safety profile and antitumor activity of an allogeneic prostate carcinoma cell line, LNCaP, expressing recombinant human interleukin-2 and human interferon-gamma. Thirty HLA-A*0201-matched patients with progressive, castration-resistant prostate cancer received four intradermal injections on days 1, 15, 29, and 92, and then every 90 days, as long as no tumor progression occurred. Three patients received a dose level of 7.5 million cells, and 27 patients received 15 million cells per injection. The primary study criteria were safety and the difference in prostate-specific antigen doubling time (PSA-DT), determined in the pretreatment phase (before the start of vaccination) and in the trial treatment phase (during vaccination). No dose-limiting or autoimmune toxicity was seen. During vaccination there was a significant prolongation of the PSA-DT compared with the prevaccination period (prolongation from 63 to 114 days; p < 0.01; intention to treat). In addition, results showed a period of PSA stabilization of at least 12 weeks, together with stable bone scans in 12 of 30 patients, and 3 patients sustained a >50% decrease in PSA versus baseline. The median overall survival time from first vaccination was 32 months (mean value, 34 months). Immune monitoring revealed T cell stimulation in the majority of patients. This vaccine strategy was found to be safe and well tolerated and was accompanied by prolongation of PSA-DT. The results of this trial warrant clinical development of this vaccine.

  17. Targeting Androgen Receptor Aberrations in Castration-Resistant Prostate Cancer.

    PubMed

    Sharp, Adam; Welti, Jonathan; Blagg, Julian; de Bono, Johann S

    2016-09-01

    Androgen receptor (AR) splice variants (SV) have been implicated in the development of metastatic castration-resistant prostate cancer and resistance to AR targeting therapies, including abiraterone and enzalutamide. Agents targeting AR-SV are urgently needed to test this hypothesis and further improve the outcome of patients suffering from this lethal disease. Clin Cancer Res; 22(17); 4280-2. ©2016 AACRSee related article by Yang et al., p. 4466.

  18. MicroRNA expression signature of castration-resistant prostate cancer: the microRNA-221/222 cluster functions as a tumour suppressor and disease progression marker

    PubMed Central

    Goto, Yusuke; Kojima, Satoko; Nishikawa, Rika; Kurozumi, Akira; Kato, Mayuko; Enokida, Hideki; Matsushita, Ryosuke; Yamazaki, Kazuto; Ishida, Yasuo; Nakagawa, Masayuki; Naya, Yukio; Ichikawa, Tomohiko; Seki, Naohiko

    2015-01-01

    Background: Our present study of the microRNA (miRNA) expression signature in castration-resistant prostate cancer (CRPC) revealed that the clustered miRNAs microRNA-221 (miR-221) and microRNA-222 (miR-222) are significantly downregulated in cancer tissues. The aim of this study was to investigate the functional roles of miR-221 and miR-222 in prostate cancer (PCa) cells. Methods: A CRPC miRNA signature was constructed by PCR-based array methods. Functional studies of differentially expressed miRNAs were analysed using PCa cells. The association between miRNA expression and overall survival was estimated by the Kaplan–Meier method. In silico database and genome-wide gene expression analyses were performed to identify molecular targets regulated by the miR-221/222 cluster. Results: miR-221 and miR-222 were significantly downregulated in PCa and CRPC specimens. Kaplan–Meier survival curves showed that low expression of miR-222 predicted a short duration of progression to CRPC. Restoration of miR-221 or miR-222 in cancer cells revealed that both miRNAs significantly inhibited cancer cell migration and invasion. Ecm29 was directly regulated by the miR-221/222 cluster in PCa cells. Conclusions: Loss of the tumour-suppressive miR-221/222 cluster enhanced migration and invasion in PCa cells. Our data describing targets regulated by the tumour-suppressive miR-221/222 cluster provide insights into the mechanisms of PCa and CRPC progression. PMID:26325107

  19. Phase I/II trial of cabazitaxel plus abiraterone in patients with metastatic castration-resistant prostate cancer (mCRPC) progressing after docetaxel and abiraterone

    PubMed Central

    Mateo, J.; Loriot, Y.; Pezaro, C.; Albiges, L.; Mehra, N.; Varga, A.; Bianchini, D.; Ryan, C. J.; Petrylak, D. P.; Attard, G.; Shen, L.; Fizazi, K.; de Bono, J.

    2017-01-01

    Abstract Background Abiraterone and cabazitaxel improve survival in patients with metastatic castration-resistant prostate cancer (mCRPC). We conducted an open-label phase I/II trial of cabazitaxel plus abiraterone to assess the antitumor activity and tolerability in patients with progressive mCRPC after docetaxel (phase I), and after docetaxel and abiraterone (phase II) (NCT01511536). Patients and methods The primary objectives were to determine the maximum tolerated dose (MTD) and dose-limiting toxicities (DLTs) of cabazitaxel plus abiraterone (phase I), and the prostate-specific antigen (PSA) response defined as a ≥ 50% decrease confirmed ≥3 weeks later with this combination (phase II). Results Ten patients were enrolled in the phase I component; nine were evaluable. No DLTs were identified. The MTD was established as the approved doses for both drugs (cabazitaxel 25 mg/m2 every 3 weeks and abiraterone 1000 mg once daily). Daily abiraterone treatment did not impact on cabazitaxel clearance. Twenty-seven patients received cabazitaxel plus abiraterone plus prednisone (5 mg twice daily) in phase II. The median number of cycles administered (cabazitaxel) was seven (range: 1–28). Grade 3–4 treatment-emergent adverse events included asthenia (in 5 patients; 14%), neutropenia (in 5 patients; 14%) and diarrhea (in 3 patients; 8%). Nine patients (24%) required dose reductions of cabazitaxel. Of 26 evaluable patients, 12 achieved a PSA response [46%; 95% confidence interval (CI): 26.6–66.6%]. Median PSA-progression-free survival was 6.9 months (95% CI: 4.1–10.3 months). Of 14 patients with measurable disease at baseline, 3 (21%) achieved a partial response per response evaluation criteria in solid tumors. Conclusions The combination of cabazitaxel and abiraterone has a manageable safety profile and shows antitumor activity in patients previously treated with docetaxel and abiraterone. PMID:28039155

  20. Development of a New Class of Drugs To Inhibit All Forms of Androgen Receptor in Castration Resistant Prostate Cancers

    DTIC Science & Technology

    2016-10-01

    AWARD NUMBERS: W81XWH-14-1-0519 TITLE: Development of a New Class of Drugs to Inhibit All Forms of Androgen Receptor in Castration- Resistant...DATES COVERED 30Sep2015 - 29Sep2016 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER W81XWH-14-1-0519 Development of a New Class of Drugs To Inhibit...of drugs targeting the androgen/AR signaling axis, progression of castration-resistant prostate cancer (CRPC) remains a major clinical challenge

  1. A profile of enzalutamide for the treatment of advanced castration resistant prostate cancer

    PubMed Central

    Greasley, Rosa; Khabazhaitajer, Mohammad; Rosario, Derek J

    2015-01-01

    Recent advances in understanding the mechanisms underlying the development and progression of castration resistant prostate cancer from androgen-sensitive prostate cancer have provided new avenues exploring efficacious therapies in a disease which is the second leading cause of cancer deaths among men in the western world. In the evolution of second generation anti-androgens, enzalutamide, a novel androgen-receptor signaling inhibitor, has emerged targeting multiple steps within the androgenic stimulation pathway. This review discusses what is currently known of the mechanisms surrounding castration resistant prostate cancer development and the current human clinical trials to determine whether enzalutamide presents a new hope for men with advanced prostate cancer. The issues of therapy resistance, withdrawal effects and cross-resistance are briefly touched upon. PMID:26109877

  2. Treatment sequencing in metastatic castrate-resistant prostate cancer

    PubMed Central

    Sartor, Oliver; Gillessen, Silke

    2014-01-01

    Six different treatments have demonstrated improved survival in phase III trials targeted to patients with metastatic castration-resistant prostate cancer (mCRPC). Front-line therapeutic options for mCRPC include docetaxel, sipuleucel-T, abiraterone and radium-223. Post-docetaxel options include cabazitaxel, abiraterone, enzalutamide and radium-223. Despite much progress in recent years, much is yet unknown and debates occur over optimal treatment choices and sequences. None of the new agents have been compared to one another, thus physicians in practice today must make choices based on non-randomized comparisons, toxicity considerations and various assumptions. Abiraterone is now moving into the front line mCRPC space given recent regulatory approvals and enzalutamide will follow soon. Both of the hormonal agents have less toxicity when compared to chemotherapeutic options and both of these hormonal agents are expected to be used in a considerable number of mCRPC patients in the years ahead. Little data are available for the post-abiraterone or post-enzalutamide setting. In this review the currently available sequencing data are summarized and interpreted. It is now clear that cross resistance is a potential issue between various treatments, especially those agents that target the androgen axis. This review highlights the need for additional studies to optimize the current treatments for these patients. PMID:24675654

  3. Radiographic Progression-Free Survival As a Response Biomarker in Metastatic Castration-Resistant Prostate Cancer: COU-AA-302 Results

    PubMed Central

    Morris, Michael J.; Molina, Arturo; Small, Eric J.; de Bono, Johann S.; Logothetis, Christopher J.; Fizazi, Karim; de Souza, Paul; Kantoff, Philip W.; Higano, Celestia S.; Li, Jinhui; Kheoh, Thian; Larson, Steven M.; Matheny, Shannon L.; Naini, Vahid; Burzykowski, Tomasz; Griffin, Thomas W.; Scher, Howard I.; Ryan, Charles J.

    2015-01-01

    Purpose Progression-free survival (PFS) in metastatic castration-resistant prostate cancer (mCRPC) trials has been inconsistently defined and poorly associated with overall survival (OS). A reproducible quantitative definition of radiographic PFS (rPFS) was tested for association with a coprimary end point of OS in a randomized trial of abiraterone in patients with mCRPC. Patients and Methods rPFS was defined as ≥ two new lesions on an 8-week bone scan plus two additional lesions on a confirmatory scan, ≥ two new confirmed lesions on any scan ≥ 12 weeks after random assignment, and/or progression in nodes or viscera on cross-sectional imaging, or death. rPFS was assessed by independent review at 15% of deaths and by investigator review at 15% and 40% of deaths. rPFS and OS association was evaluated by Spearman's correlation. Results A total of 1,088 patients were randomly assigned to abiraterone plus prednisone or prednisone alone. At first interim analysis, the hazard ratio (HR) by independent review was 0.43 (95% CI, 0.35 to 0.52; P < .001; abiraterone plus prednisone: median rPFS, not estimable; prednisone: median rPFS, 8.3 months). Similar HRs were obtained by investigator review at the first two interim analyses (HR, 0.49; 95% CI, 0.41 to 0.60; P < .001 and HR, 0.53; 95% CI, 0.45 to 0.62; P < .001, respectively), validating the imaging data assay used. Spearman's correlation coefficient between rPFS and OS was 0.72. Conclusion rPFS was highly consistent and highly associated with OS, providing initial prospective evidence on further developing rPFS as an intermediate end point in mCRPC trials. PMID:25624432

  4. Progression-free and overall survival in metastatic castration-resistant prostate cancer treated with abiraterone acetate can be predicted with serial C11-acetate PET/CT

    PubMed Central

    Farnebo, Jacob; Wadelius, Agnes; Sandström, Per; Nilsson, Sten; Jacobsson, Hans; Blomqvist, Lennart; Ullén, Anders

    2016-01-01

    Abstract In this retrospective study, we evaluated the benefit of repeated carbon 11 (C11)-acetate positron emission tomography/computed tomography (PET/CT) to assess response in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with abiraterone acetate (AA). A total of 30 patients with mCRPC were monitored with C11-acetate PET/CT and PSA levels during their treatment with AA. Retrospective evaluation of their response was made after 102 days (median; range 70–155) of treatment. Statistical analyses were employed to detect predictors of progression-free survival (PFS) and overall survival (OS), and potential correlation between serum levels of PSA, standardized uptake values (SUVpeak), and bone lesion index measured from PET were investigated. At follow-up 10 patients exhibited partial response (PR), 10 progressive disease (PD), and 10 stable disease (SD), as assessed by PET/CT. In survival analysis, both PR and PD were significantly associated with PFS and OS. CT response was also associated with OS, but only 19/30 patients demonstrated a lesion meeting target lesion criteria according to RECIST 1.1. No PET/CT baseline characteristic was significantly associated with PFS or OS. A PSA response (reduction in the level by >50%) could also predict PFS and OS. In the subgroup lacking a PSA response, those with PD had significantly shorter OS than those with PR or SD. PFS and OS in patients with mCRPC treated with AA can be predicted from repeated C11-acetate PET/CT. This may be of particular clinical value in patients who do not exhibit a PSA response to treatment. PMID:27495034

  5. Progression-free and overall survival in metastatic castration-resistant prostate cancer treated with abiraterone acetate can be predicted with serial C11-acetate PET/CT.

    PubMed

    Farnebo, Jacob; Wadelius, Agnes; Sandström, Per; Nilsson, Sten; Jacobsson, Hans; Blomqvist, Lennart; Ullén, Anders

    2016-08-01

    In this retrospective study, we evaluated the benefit of repeated carbon 11 (C11)-acetate positron emission tomography/computed tomography (PET/CT) to assess response in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with abiraterone acetate (AA).A total of 30 patients with mCRPC were monitored with C11-acetate PET/CT and PSA levels during their treatment with AA. Retrospective evaluation of their response was made after 102 days (median; range 70-155) of treatment. Statistical analyses were employed to detect predictors of progression-free survival (PFS) and overall survival (OS), and potential correlation between serum levels of PSA, standardized uptake values (SUVpeak), and bone lesion index measured from PET were investigated.At follow-up 10 patients exhibited partial response (PR), 10 progressive disease (PD), and 10 stable disease (SD), as assessed by PET/CT. In survival analysis, both PR and PD were significantly associated with PFS and OS. CT response was also associated with OS, but only 19/30 patients demonstrated a lesion meeting target lesion criteria according to RECIST 1.1. No PET/CT baseline characteristic was significantly associated with PFS or OS. A PSA response (reduction in the level by >50%) could also predict PFS and OS. In the subgroup lacking a PSA response, those with PD had significantly shorter OS than those with PR or SD.PFS and OS in patients with mCRPC treated with AA can be predicted from repeated C11-acetate PET/CT. This may be of particular clinical value in patients who do not exhibit a PSA response to treatment.

  6. Statin derivatives as therapeutic agents for castration-resistant prostate cancer.

    PubMed

    Ingersoll, Matthew A; Miller, Dannah R; Martinez, October; Wakefield, C Brent; Hsieh, Kuan-Chan; Simha, M Vijaya; Kao, Chai-Lin; Chen, Hui-Ting; Batra, Surinder K; Lin, Ming-Fong

    2016-12-01

    Despite recent advances in modern medicine, castration-resistant prostate cancer remains an incurable disease. Subpopulations of prostate cancer cells develop castration-resistance by obtaining the complete steroidogenic ability to synthesize androgens from cholesterol. Statin derivatives, such as simvastatin, inhibit cholesterol biosynthesis and may reduce prostate cancer incidence as well as progression to advanced, metastatic phenotype. In this study, we demonstrate novel simvastatin-related molecules SVA, AM1, and AM2 suppress the tumorigenicity of prostate cancer cell lines including androgen receptor-positive LNCaP C-81 and VCaP as well as androgen receptor-negative PC-3 and DU145. This is achieved through inhibition of cell proliferation, colony formation, and migration as well as induction of S-phase cell-cycle arrest and apoptosis. While the compounds effectively block androgen receptor signaling, their mechanism of inhibition also includes suppression of the AKT pathway, in part, through disruption of the plasma membrane. SVA also possess an added effect on cell growth inhibition when combined with docetaxel. In summary, of the compounds studied, SVA is the most potent inhibitor of prostate cancer cell tumorigenicity, demonstrating its potential as a promising therapeutic agent for castration-resistant prostate cancer.

  7. Phase I clinical trial of sipuleucel-T combined with escalating doses of ipilimumab in progressive metastatic castrate-resistant prostate cancer

    PubMed Central

    Scholz, Mark; Yep, Sabrina; Chancey, Micah; Kelly, Colleen; Chau, Ken; Turner, Jeffrey; Lam, Richard; Drake, Charles G

    2017-01-01

    Background Sipuleucel-T (SIP-T), which functions by stimulating cancer-specific dendritic cells, prolongs survival in men with prostate cancer. Ipilimumab (IPI) achieved a borderline survival advantage in a large randomized trial. SIP-T and IPI are potentially synergistic. Patients and Methods Nine men with progressive metastatic castrate-resistant prostate cancer (mCRPC) were treated prospectively with SIP-T followed immediately by IPI with one of the following doses of IPI: 1 mg/kg at 1 week after SIP-T; 1 mg/kg at 1 and 4 weeks after SIP-T; or 1 mg/kg at 1, 4, and 7 weeks after SIP-T. Three patients were evaluated at each level. Cancer-specific immunoglobulins directed at granulocyte-macrophage-colony-stimulating factor/prostatic acid phosphatase (PAP) fusion protein (PA2024) and PAP were measured prior to SIP-T, after SIP-T, 1 week after IPI, every other month for 5 months, then every 3 months for an additional 12 months. Results Adverse events of SIP-T were consistent with previous reports. IPI only caused a transient grade 1 rash in one patient. Median age, Gleason score, and number of previous hormonal interventions were 77 years, 8, and 3, respectively. Eight men had bone metastases and one had lymph node metastasis. Statistically significant increases in serum immunoglobulin G (IgG) and IgG-IgM specific for PA2024 and PAP occurred after SIP-T. An additional statistically significant increase in the aforementioned immunoglobulins – above the levels achieved by SIP-T – occurred after IPI. Median clinical follow-up was 36 months (range: 26–40). Three patients died from progressive disease after 9, 18, and 20 months. Out of the remaining six patients, five of them needed further treatment that included abiraterone acetate, enzalutamide, radium-223 dichloride, and spot radiation. One patient had an undetectable PSA, who did not receive any other treatment except spot radiation. Median PSA at last follow-up for the surviving patients was 3.8 (range: 0.6

  8. Sortilin Regulates Progranulin Action in Castration-Resistant Prostate Cancer Cells

    PubMed Central

    Tanimoto, Ryuta; Morcavallo, Alaide; Terracciano, Mario; Xu, Shi-Qiong; Stefanello, Manuela; Buraschi, Simone; Lu, Kuojung G.; Bagley, Demetrius H.; Gomella, Leonard G.; Scotlandi, Katia; Belfiore, Antonino; Iozzo, Renato V.

    2015-01-01

    The growth factor progranulin is as an important regulator of transformation in several cellular systems. We have previously demonstrated that progranulin acts as an autocrine growth factor and stimulates motility, proliferation, and anchorage-independent growth of castration-resistant prostate cancer cells, supporting the hypothesis that progranulin may play a critical role in prostate cancer progression. However, the mechanisms regulating progranulin action in castration-resistant prostate cancer cells have not been characterized. Sortilin, a single-pass type I transmembrane protein of the vacuolar protein sorting 10 family, binds progranulin in neurons and negatively regulates progranulin signaling by mediating progranulin targeting for lysosomal degradation. However, whether sortilin is expressed in prostate cancer cells and plays any role in regulating progranulin action has not been established. Here, we show that sortilin is expressed at very low levels in castration-resistant PC3 and DU145 cells. Significantly, enhancing sortilin expression in PC3 and DU145 cells severely diminishes progranulin levels and inhibits motility, invasion, proliferation, and anchorage-independent growth. In addition, sortilin overexpression negatively modulates Akt (protein kinase B, PKB) stability. These results are recapitulated by depleting endogenous progranulin in PC3 and DU145 cells. On the contrary, targeting sortilin by short hairpin RNA approaches enhances progranulin levels and promotes motility, invasion, and anchorage-independent growth. We dissected the mechanisms of sortilin action and demonstrated that sortilin promotes progranulin endocytosis through a clathrin-dependent pathway, sorting into early endosomes and subsequent lysosomal degradation. Collectively, these results point out a critical role for sortilin in regulating progranulin action in castration-resistant prostate cancer cells, suggesting that sortilin loss may contribute to prostate cancer progression

  9. Bone targeted therapies in metastatic castration-resistant prostate cancer.

    PubMed

    Rajpar, Shanna; Fizazi, Karim

    2013-01-01

    Prostate cancer is the most common male cancer. About 90% of metastatic patients will develop bone metastases. Bone disease is responsible of pain, deterioration of quality of life and serious bone complications. Proliferation of prostate cancer cells in the bone marrow induces osteoclast activation and osteolysis. Targeting the bone microenvironment reduces morbidity. Relevant preclinical and clinical studies of bone-targeted therapies in castration-resistant prostate cancer were identified in PubMed and clinical trial databases. Different drugs are available or in development that target bone resorption (bisphosphonates, RANK ligand inhibitors), bone formation (endothelin 1 inhibitors), cancer cell migration (SRC-family kinase inhibitors, vascular endothelial growth factor-MET inhibitors), and survival (radiopharmaceuticals). In phase III trials, zoledronic acid, denosumab, and radium-223 were shown to significantly delay skeletal-related events. Radium-223 was also shown to improve overall survival. Biomarkers of bone resorption (urinary N-telopeptide) and bone making (alkaline phosphatase) have an independent prognostic impact. Targeting the bone microenvironment is an important component of castration-resistant prostate cancer management to reduce bone complications and improve overall survival. Biomarkers of bone turnover have an independent prognostic impact.

  10. Crosstalk between epithelial-mesenchymal transition and castration resistance mediated by Twist1/AR signaling in prostate cancer.

    PubMed

    Shiota, Masaki; Itsumi, Momoe; Takeuchi, Ario; Imada, Kenjiro; Yokomizo, Akira; Kuruma, Hidetoshi; Inokuchi, Junichi; Tatsugami, Katsunori; Uchiumi, Takeshi; Oda, Yoshinao; Naito, Seiji

    2015-12-01

    Although invasive and metastatic progression via the epithelial-mesenchymal transition (EMT) and acquisition of resistance to castration are both critical steps in prostate cancer, the molecular mechanism of this interaction remains unclear. In this study, we aimed to elucidate the interaction of signaling between castration resistance and EMT, and to apply this information to the development of a novel therapeutic concept using transforming growth factor-β (TGF-β) inhibitor SB525334 combined with androgen-deprivation therapy against prostate cancer using an in vivo model. This study revealed that an EMT inducer (TGF-β) induced full-length androgen receptor (AR) and AR variant expression. In addition, a highly invasive clone showed augmented full-length AR and AR variant expression as well as acquisition of castration resistance. Conversely, full-length AR and AR as well as Twist1 and mesenchymal molecules variant expression were up-regulated in castration-resistant LNCaP xenograft. Finally, TGF-β inhibitor suppressed Twist1 and AR expression as well as prostate cancer growth combined with castration. Taken together, these results demonstrate that Twist1/AR signaling was augmented in castration resistant as well as mesenchymal-phenotype prostate cancer, indicating the molecular mechanism of mutual and functional crosstalk between EMT and castration resistance, which may play a crucial role in prostate carcinogenesis and progression.

  11. A Phase I/II Study of the Investigational Drug Alisertib in Combination With Abiraterone and Prednisone for Patients With Metastatic Castration-Resistant Prostate Cancer Progressing on Abiraterone

    PubMed Central

    Patel, Sheel A.; Sama, Ashwin R.; Hoffman-Censits, Jean H.; Kennedy, Brooke; Kilpatrick, Deborah; Ye, Zhong; Yang, Hushan; Mu, Zhaomei; Leiby, Benjamin; Lewis, Nancy; Cristofanilli, Massimo; Kelly, William Kevin

    2016-01-01

    Lessons Learned Patients with metastatic castration-resistant prostate cancer did not tolerate the combination of alisertib with abiraterone and prednisone. There was no clear signal indicating that adding alisertib might be beneficial for those patients progressing on abiraterone. Background. We hypothesized that Aurora A kinase (AK) contributes to castrate resistance in prostate cancer (PCa) and that inhibiting AK with alisertib can resensitize PCa cells to androgen receptor (AR) inhibitor abiraterone. Methods. This was a phase I/II trial to determine the safety and efficacy of alisertib when given in combination with abiraterone plus prednisone (AP). Metastatic castration-resistant prostate cancer (mCRPC) patients were treated with dose escalation (alisertib at 30, 40, and 50 mg orally b.i.d., days 1–7 every 21 days) per standard 3+3 design. Results. Nine of 43 planned subjects were enrolled. The maximum tolerated dose (MTD) was not reached, and the dose-limiting toxicities (DLTs) included neutropenic fever (1 of 9), neutropenia (1 of 9), fatigue with memory impairment (1 of 9), and diarrhea/mucositis (1 of 9). No prostate-specific antigen (PSA) decrease or circulating tumor cell (CTC) changes were observed during the study. Pharmacodynamically, adding alisertib did not affect total testosterone or dehydroepiandrosterone (DHEA) levels. There was some change in neuroendocrine markers after therapy. Mean duration on study was 2.5 months. The trial was terminated early. Conclusion. A tolerable dose of alisertib in combination with AP in mCRPC was not established in this study. There was no clear signal indicating that alisertib might be beneficial for patients with mCRPC progressing on abiraterone. PMID:28178640

  12. Perspectives on Treatment of Metastatic Castration-Resistant Prostate Cancer

    PubMed Central

    Bellmunt, Joaquim; Jenkins, Cheryl; Parker, Chris; Fitzpatrick, John M.

    2013-01-01

    The arrival of several new agents—cabazitaxel, abiraterone acetate, enzalutamide, and radium-223—is changing the treatment options and management of patients with metastatic castration-resistant prostate cancer (mCRPC). Many other novel agents are also being investigated. As new drugs become approved, new treatment strategies and markers to best select which patients will best respond to which drug are needed. This review article is a summary of a European Treatment Practices Meeting, which was convened to discuss these latest data on novel agents and current treatment strategies in the mCRPC setting. PMID:23671006

  13. Current management of advanced and castration resistant prostate cancer.

    PubMed

    Gomella, Leonard G; Petrylak, Daniel P; Shayegan, Bobby

    2014-04-01

    Newer approaches to the management of advanced prostate cancer have rapidly evolved. While basic androgen deprivation remains as the first line in newly diagnosed hormone naïve metastatic prostate cancer, the agents used and strategies followed have undergone significant changes. Numerous new agents such as sipuleucel-T, abiraterone, enzalutamide, cabazitaxel and radium 223 have all been approved since 2010 to treat metastatic castration resistant prostate cancer (CRPC). New imaging techniques to detect advanced disease such as F-18 PET, 11 C-choline PET and other modalities are becoming available. The concepts of "bone health" and the management of side effects related to androgen deprivation therapy are also gaining attention as men are being treated with longer courses of androgen deprivation. Understanding the theory behind these new agents and management approaches while focusing on the practical clinical considerations are essential to improve outcomes in advanced prostate cancer. A review of the current state of the art in the management of advanced and castration resistant prostate cancer presented in this Canadian Journal of Urology International supplement was performed. Key findings are summarized and presented along with critical updates based on recent publications and meeting presentations. Key concepts identified in the management of advanced prostate cancer included the new understanding of prostate cancer based on translational discoveries, applications of various hormonally based strategies in advanced disease including traditional and recently approved agents. The use of new imaging modalities to identify metastatic disease, immunotherapy approaches and discussions of sequencing and which new agents are likely to be available in the future in the management of CRPC were identified. Bone targeted strategies are also addressed in the setting of androgen deprivation and metastatic disease. The management of men with advanced prostate cancer has

  14. Lactate dehydrogenase predicts combined progression-free survival after sequential therapy with abiraterone and enzalutamide for patients with castration-resistant prostate cancer.

    PubMed

    Mori, Keiichiro; Kimura, Takahiro; Onuma, Hajime; Kimura, Shoji; Yamamoto, Toshihiro; Sasaki, Hiroshi; Miki, Jun; Miki, Kenta; Egawa, Shin

    2017-07-01

    An array of clinical issues remains to be resolved for castration-resistant prostate cancer (CRPC), including the sequence of drug use and drug cross-resistance. At present, no clear guidelines are available for the optimal sequence of use of novel agents like androgen-receptor axis-targeted (ARAT) agents, particularly enzalutamide, and abiraterone. This study retrospectively analyzed a total of 69 patients with CRPC treated with sequential therapy using enzalutamide followed by abiraterone or vice versa. The primary outcome measure was the comparative combined progression-free survival (PFS) comprising symptomatic and/or radiographic PFS. Patients were also compared for total prostate-specific antigen (PSA)-PFS, overall survival (OS), and PSA response. The predictors of combined PFS and OS were analyzed with a backward-stepwise multivariate Cox model. Of the 69 patients, 46 received enzalutamide first, followed by abiraterone (E-A group), and 23 received abiraterone, followed by enzalutamide (A-E group). The two groups were not significantly different with regard to basic data, except for hemoglobin values. In a comparison with the E-A group, the A-E group was shown to be associated with better combined PFS in Kaplan-Meier analysis (P = 0.043). Similar results were obtained for total PSA-PFS (P = 0.049), while OS did not differ between groups (P = 0.62). Multivariate analysis demonstrated that pretreatment lactate dehydrogenase (LDH) values and age were significant predictors of longer combined PFS (P < 0.05). Likewise, multivariate analysis demonstrated that pretreatment hemoglobin values and performance status were significant predictors of longer OS (P < 0.05). The results of this study suggested the A-E sequence had longer combined PSA and total PSA-PFS compared to the E-A sequence in patients with CRPC. LDH values in sequential therapy may serve as a predictor of longer combined PFS. © 2017 Wiley Periodicals, Inc.

  15. Free Testosterone During Androgen Deprivation Therapy Predicts Castration-Resistant Progression Better Than Total Testosterone.

    PubMed

    Regis, Lucas; Planas, Jacques; Carles, Joan; Maldonado, Xavier; Comas, Inma; Ferrer, Roser; Morote, Juan

    2017-01-01

    The optimal degree of testosterone suppression in patients with prostate cancer undergoing androgen deprivation therapy remains in question. Furthermore, serum free testosterone, which is the active form of testosterone, seems to correlate with intraprostatic testosterone. Here we compared free and total serum testosterone as predictors of survival free of castration resistance. Total testosterone (chemiluminescent assay, lower sensitivity 10 ng/dl) and free testosterone (analogue-ligand radioimmunoassay, lower sensitivity 0.05 pg/ml) were determined at 6 months of LHRH agonist treatment in a prospective cohort of 126 patients with prostate cancer. During a mean follow-up of 67 months (9-120), 75 (59.5%) events of castration-resistant progression were identified. Multivariate analysis and survival analysis according to total testosterone cutoffs of 50, 32, and 20 ng/dl, and free testosterone cutoffs of 1.7, 1.1, and 0.7 pg/ml were performed. Metastatic spread was the most powerful predictor of castration resistance, HR: 2.09 (95%CI: 1.18-3.72), P = 0.012. Gleason score, baseline PSA and PSA at 6 months were also independents predictors, but not free and total testosterone. Stratified analysis was conducted on the basis of the status of metastatic diseases and free testosterone was found to be an independent predictor of survival free of castration resistance in the subgroup of patients without metastasis, HR: 2.12 (95%CI: 1.16-3.85), P = 0.014. The lowest threshold of free testosterone which showed significant differences was 1.7 pg/ml, P = 0.003. Free testosterone at 6 months of LHRH agonist treatment seems to be a better surrogate than total testosterone to predict castration resistance in no metastatic prostate cancer patients. Prostate 77:114-120, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  16. [Peptide vaccination for castration-resistant prostate cancer].

    PubMed

    Koga, Noriko; Noguchi, Masanori

    2014-12-01

    Since both tumor cells and host immune cell repertoires are diverse and heterogeneous, immune responses against tumor associated antigens shall be substantially different among individual patients with prostate cancer. Subsequently, selection of suitable peptide vaccines for individual patients based on the pre-existing host immunity before vaccination could induce potent anti-tumor responses capable of providing clinical benefit for prostate cancer patients. We have developed a novel immunotherapeutic approach of personalized peptide vaccination (PPV) in which a maximum of four human leukocyte antigen (HLA)-class IA-matched peptides were selected for vaccination among pooled peptides based on both HLA-class IA type and the pre-existing host immunity before vaccination. We discuss our recent results of clinical studies of peptide vaccination for castration-resistant prostate cancer and the future direction of therapeutic cancer vaccines.

  17. Sipuleucel-T: in metastatic castration-resistant prostate cancer.

    PubMed

    Plosker, Greg L

    2011-01-01

    Sipuleucel-T is an autologous active cellular immunotherapy used in the treatment of men with asymptomatic or minimally symptomatic metastatic castration-resistant prostate cancer (CRPC). It is the first therapeutic cancer vaccine to receive US FDA approval. Approximately 3 days prior to each infusion of sipuleucel-T, patients undergo a leukapheresis procedure for collection of autologous peripheral blood mononuclear cells. Preparation of sipuleucel-T involves enrichment for antigen-presenting cells from the leukapheresis product and activation ex vivo with a recombinant fusion protein (PA2024). In the randomized, double-blind, placebo-controlled IMPACT study in patients with metastatic CRPC, sipuleucel-T was associated with a 22% relative reduction in the risk of death (hazard ratio 0.78; p = 0.03), which was the primary endpoint of the trial. After a median follow-up period of 34.1 months, median survival was 4.1 months longer with sipuleucel-T than placebo (25.8 vs 21.7 months). There was no significant between-group difference for the median time to objective disease progression (a secondary endpoint). Almost all patients treated with sipuleucel-T in clinical trials reported an adverse event, although these were mild or moderate in severity (grade 1 or 2) in most patients. The most common adverse events (e.g. infusion-related events, such as chills and fever) generally occurred within the first day after administration of sipuleucel-T and resolved within 2 days.

  18. Developing imaging strategies for castration resistant prostate cancer

    PubMed Central

    Fox, Josef J.; Morris, Michael J.; Larson, Steven M.; Schöder, Heiko; Scher, Howard I.

    2012-01-01

    Recent advances in the understanding of castrate-resistant prostate cancer (CRPC) have lead to a growing number of experimental therapies, many of which are directed against the androgen-receptor (AR) signaling axis. These advances generate the need for reliable molecular imaging biomarkers to non-invasively determine efficacy, and to better guide treatment selection of these promising AR-targeted drugs. Methods We draw on our own experience, supplemented by review of the current literature, to discuss the systematic development of imaging biomarkers for use in the context of CRPC, with a focus on bone scintigraphy, F-18 fluorodeoxyglucose (FDG)-positron emission tomography (PET) and PET imaging of the AR signaling axis. Results The roadmap to biomarker development mandates rigorous standardization and analytic validation of an assay before it can be qualified successfully for use in an appropriate clinical context. The Prostate Cancer Working Group 2 (PCWG2) criteria for “radiographic” progression by bone scintigraphy serve as a paradigm of this process. Implemented by the Prostate Cancer Clinical Trials Consortium (PCCTC), these consensus criteria may ultimately enable the co-development of more potent and versatile molecular imaging biomarkers. Purported to be superior to single-photon bone scanning, the added value of Na18F-PET for imaging of bone metastases is still uncertain. FDG-PET already plays an integral role in the management of many diseases, but requires further evaluation before being qualified in the context of CRPC. PET tracers that probe the AR signaling axis, such as 18F-FDHT and 89Zr-591, are now under development as pharmacodynamic markers, and as markers of efficacy, in tandem with FDG-PET. Semi-automated analysis programs for facilitating PET interpretation may serve as a valuable tool to help navigate the biomarker roadmap. Conclusions Molecular imaging strategies, particularly those that probe the AR signaling axis, have the potential

  19. Radium Ra 223 dichloride in castration-resistant prostate cancer.

    PubMed

    Joung, J Y; Ha, Y S; Kim, I Y

    2013-08-01

    Radium Ra 223 dichloride (Xofigo®, formerly Alpharadin) is one of the representative α-particle-emitting isotopes that delivers radiation with a higher biological effect to a more localized area. Preclinical studies in mouse, rat and canine models have demonstrated that radium Ra 223 dichloride has a definite skeletal affinity and antitumor effect with a relatively low toxicity on bone marrow. More recently, in a large randomized phase III trial (ALSYMPCA), patients with bone metastasis and castration-resistant prostate cancer (CRPC) received six cycles of 50 kBq/kg of radium Ra 223 dichloride in 4-week intervals. In these men, radium Ra 223 dichloride improved the median overall survival by 3.6 months when compared to the placebo group. Collectively, these results suggest that radium Ra 223 dichloride is a promising candidate for managing bone metastases in patients with CRPC.

  20. Overcoming Autophagy to Induce Apoptosis in Castration-Resistant Prostate Cancer

    DTIC Science & Technology

    2016-12-01

    AWARD NUMBER: W81XWH-12-1-0529 TITLE: Overcoming Autophagy to Induce Apoptosis in Castration-Resistant Prostate Cancer PRINCIPAL INVESTIGATOR...TITLE AND SUBTITLE 5a. CONTRACT NUMBER W81XWH-12-1-0529 Overcoming Autophagy to Induce Apoptosis in Castration-Resistant Prostate Cancer 5b...of the next generation anti-androgens such as enzalutamide and abiraterone (Abi) for advanced prostate cancer therapy, we attempted to evaluate

  1. Development of a New Class of Drugs to Inhibit All Forms of Androgen Receptor in Castration Resistant Prostate Cancers

    DTIC Science & Technology

    2016-10-01

    AWARD NUMBERS: W81XWH-14-1-0520 TITLE: Development of a New Class of Drugs to Inhibit All Forms of Androgen Receptor in Castration- Resistant...Annual 3. DATES COVERED 30Sep2015 - 29Sep2016 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER W81XWH-14-1-0520 Development of a New Class of Drugs To...armamentarium of drugs targeting the androgen/AR signaling axis, progression of castration-resistant prostate cancer (CRPC) remains a major clinical

  2. Targeting Oct1 genomic function inhibits androgen receptor signaling and castration-resistant prostate cancer growth.

    PubMed

    Obinata, D; Takayama, K; Fujiwara, K; Suzuki, T; Tsutsumi, S; Fukuda, N; Nagase, H; Fujimura, T; Urano, T; Homma, Y; Aburatani, H; Takahashi, S; Inoue, S

    2016-12-08

    Androgen receptor (AR) functions as a ligand-dependent transcription factor to regulate its downstream signaling for prostate cancer progression. AR complex formation by multiple transcription factors is important for enhancer activity and transcriptional regulation. However, the significance of such collaborative transcription factors has not been fully understood. In this study, we show that Oct1, an AR collaborative factor, coordinates genome-wide AR signaling for prostate cancer growth. Using global analysis by chromatin immunoprecipitation sequencing (ChIP-seq), we found that Oct1 is recruited to AR-binding enhancer/promoter regions and facilitates androgen signaling. Moreover, a major target of AR/Oct1 complex, acyl-CoA synthetase 3 (ACSL3), contributes to tumor growth in nude mice, and its high expression is associated with poor prognosis in prostate cancer patients. Next, we examined the therapeutic effects of pyrrole-imidazole polyamides that target the Oct1-binding sequence identified in the center of the ACSL3 AR-binding site. We observed that treatment with Oct1 polyamide severely blocked the Oct1 binding at the ACSL3 enhancer responsible for its transcriptional activity and ACSL3 induction. In addition, Oct1 polyamides suppressed castration-resistant tumor growth and specifically repressed global Oct1 chromatin association and androgen signaling in prostate cancer cells, with few nonspecific effects on basal promoter activity. Thus, targeting Oct1 binding could be a novel therapeutic strategy for AR-activated castration-resistant prostate cancer.

  3. Chemotherapy options in castration-resistant prostate cancer

    PubMed Central

    Teply, Benjamin A.; Hauke, Ralph J.

    2016-01-01

    Introduction: The treatment landscape for patients with metastatic castration-resistant prostate cancer (CRPC) is evolving, with recent approvals of immune therapy, novel hormonal therapy, and bone-targeted therapy. Chemotherapy remains an essential component of the armamentarium. Herein, we review current chemotherapy options for patients with CRPC and discuss future challenges. Methods: We reviewed literature for chemotherapy agents in prostate cancer, with special attention to the evidence for efficacy of the currently approved agents. We also reviewed emerging data on biomarkers of response to chemotherapy for CRPC. Results: Taxanes, especially docetaxel and cabazitaxel, have first- and second-line indications for CRPC, respectively, with both providing a survival benefit. Multiple attempts to improve on the single agent efficacy of docetaxel with combination therapy have not generally been successful although platinum combinations are used for resistant phenotypes. Reductions in prostate-specific antigen by ≥30% and reductions in circulating tumor cells (CTCs) to ≤ 5 are associated with improved survival on chemotherapy. Chemotherapy may continue to be effective therapy for patients with biomarkers that are associated with resistance to androgen-directed therapies (androgen receptor splice variant 7 positivity in CTCs or high CTC heterogeneity). Conclusions: Chemotherapy remains an essential component of CRPC therapy, and biomarkers are being identified to define clinical scenarios where chemotherapy may be the optimal therapy choice. PMID:27843207

  4. Molecular biology of castration-resistant prostate cancer: basis for the novel therapeutic targets.

    PubMed

    Mellado, Begoña; Marin Aguilera, Mercedes; Pereira, Maria Veronica

    2013-06-01

    Prostate cancer cells express the androgen receptor (AR) and need the presence of androgens to survive. Androgen suppression is the gold standard first-line therapy for metastatic disease. Almost all prostate cancer patients initially respond to hormonal therapy, but most of them gradually develop castration-resistant progression. Recent evidence has shown that progression at the castration resistant prostate cancer (CRPC) stage is often mediated by AR signalling. Importantly, subsequent AR androgen inhibition, by abiraterone acetate or enzalutamide, has shown to improve patients' survival. Several mechanisms that enhance AR signalling in an androgen-depleted environment have been elucidated:(1) AR mutations that allow activation by low androgen levels or by other endogenous steroids, (2) AR amplification and/or overexpression,(3)increased local intracrine synthesis of androgens, (4) changes in AR cofactors and (5) cross-talk with cytokines and growth factors. Today, there are under development a number of novel agents targeting the AR signaling pathway. This article reviews the postulated mechanisms of AR-driven resistance to androgen suppression that have contributed to the development of new hormonal therapeutic strategies in prostate cancer.

  5. ASC-J9(®) suppresses castration resistant prostate cancer progression via degrading the enzalutamide-induced androgen receptor mutant AR-F876L.

    PubMed

    Wang, Ronghao; Lin, Wanying; Lin, Changyi; Li, Lei; Sun, Yin; Chang, Chawnshang

    2016-08-28

    Androgen deprivation therapy (ADT) with the newly developed powerful anti-androgen enzalutamide (Enz, also known as MDV3100) has promising therapeutic effects to suppress castration resistant prostate cancer (CRPC) and extending patients' lives an extra 4.8 months. However, most Enz therapy eventually fails with the development of Enz resistance. The detailed mechanisms how CRPC develops Enz resistance remain unclear and may involve multiple mechanisms. Among them, the induction of the androgen receptor (AR) mutant AR-F876L in some CRPC patients may represent one driving force that confers Enz resistance. Here, we demonstrate that the AR degradation enhancer, ASC-J9(®), not only degrades wild-type AR, but also has the ability to target AR-F876L. The consequence of suppressing AR-F876L may then abrogate AR-F876L mediated CRPC cell proliferation and metastasis. Thus, developing ASC-J9(®) as a new therapeutic approach may represent a novel therapy to better suppress CRPC that has already developed Enz resistance. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. NANOG reprograms prostate cancer cells to castration resistance via dynamically repressing and engaging the AR/FOXA1 signaling axis

    PubMed Central

    Jeter, Collene R; Liu, Bigang; Lu, Yue; Chao, Hsueh-Ping; Zhang, Dingxiao; Liu, Xin; Chen, Xin; Li, Qiuhui; Rycaj, Kiera; Calhoun-Davis, Tammy; Yan, Li; Hu, Qiang; Wang, Jianmin; Shen, Jianjun; Liu, Song; Tang, Dean G

    2016-01-01

    The pluripotency transcription factor NANOG has been implicated in tumor development, and NANOG-expressing cancer cells manifest stem cell properties that sustain tumor homeostasis, mediate therapy resistance and fuel tumor progression. However, how NANOG converges on somatic circuitry to trigger oncogenic reprogramming remains obscure. We previously reported that inducible NANOG expression propels the emergence of aggressive castration-resistant prostate cancer phenotypes. Here we first show that endogenous NANOG is required for the growth of castration-resistant prostate cancer xenografts. Genome-wide chromatin immunoprecipitation sequencing coupled with biochemical assays unexpectedly reveals that NANOG co-occupies a distinctive proportion of androgen receptor/Forkhead box A1 genomic loci and physically interacts with androgen receptor and Forkhead box A1. Integrative analysis of chromatin immunoprecipitation sequencing and time-resolved RNA sequencing demonstrates that NANOG dynamically alters androgen receptor/Forkhead box A1 signaling leading to both repression of androgen receptor-regulated pro-differentiation genes and induction of genes associated with cell cycle, stem cells, cell motility and castration resistance. Our studies reveal global molecular mechanisms whereby NANOG reprograms prostate cancer cells to a clinically relevant castration-resistant stem cell-like state driven by distinct NANOG-regulated gene clusters that correlate with patient survival. Thus, reprogramming factors such as NANOG may converge on and alter lineage-specific master transcription factors broadly in somatic cancers, thereby facilitating malignant disease progression and providing a novel route for therapeutic resistance. PMID:27867534

  7. Radium-223 in metastatic castration resistant prostate cancer.

    PubMed

    Vuong, Winston; Sartor, Oliver; Pal, Sumanta K

    2014-01-01

    In 2004, docetaxel was approved for the treatment of metastatic castration-resistant prostate cancer (mCRPC). For the next several years, there was a lull in drug approvals. However, from 2010 onwards, 5 additional therapies have been approved on the basis of showing a survival benefit in phase III studies. These agents include sipuleucel-T, cabazitaxel, abiraterone, enzalutamide and (most recently) radium-223. Amongst radiopharmaceuticals currently used for advanced prostate cancer (e.g. samarium-153 and strontium-89), radium-223 possesses several unique properties. As an alpha-emitting compound, the agent produces a high-energy output over a short range, facilitating selective destruction of tissue within the bone in the region of osteoblastic lesions while sparing surrounding normal tissue. The current review will outline biological rationale for radium-223 and also provide an overview of preclinical and clinical development of the agent. Rational sequencing of radium-223 and combinations, in the increasingly complex landscape of mCRPC will be discussed, along with factors influencing clinical implementation.

  8. Radium-223 in metastatic castration resistant prostate cancer

    PubMed Central

    Vuong, Winston; Sartor, Oliver; Pal, Sumanta K

    2014-01-01

    In 2004, docetaxel was approved for the treatment of metastatic castration-resistant prostate cancer (mCRPC). For the next several years, there was a lull in drug approvals. However, from 2010 onwards, 5 additional therapies have been approved on the basis of showing a survival benefit in phase III studies. These agents include sipuleucel-T, cabazitaxel, abiraterone, enzalutamide and (most recently) radium-223. Amongst radiopharmaceuticals currently used for advanced prostate cancer (e.g. samarium-153 and strontium-89), radium-223 possesses several unique properties. As an alpha-emitting compound, the agent produces a high-energy output over a short range, facilitating selective destruction of tissue within the bone in the region of osteoblastic lesions while sparing surrounding normal tissue. The current review will outline biological rationale for radium-223 and also provide an overview of preclinical and clinical development of the agent. Rational sequencing of radium-223 and combinations, in the increasingly complex landscape of mCRPC will be discussed, along with factors influencing clinical implementation. PMID:24713838

  9. Visceral disease in castration-resistant prostate cancer.

    PubMed

    Pezaro, Carmel J; Omlin, Aurelius; Lorente, David; Nava Rodrigues, Daniel; Ferraldeschi, Roberta; Bianchini, Diletta; Mukherji, Deborah; Riisnaes, Ruth; Altavilla, Amelia; Crespo, Mateus; Tunariu, Nina; de Bono, Johann S; Attard, Gerhardt

    2014-02-01

    Metastatic involvement of the viscera in men with advanced castration-resistant prostate cancer (CRPC) has been poorly characterised to date. In 359 CRPC patients treated between June 2003 and December 2011, the frequency of radiologically detected visceral metastases before death was 32%. Of the 92 patients with computed tomography performed within 3 mo of death, 49% had visceral metastases. Visceral metastases most commonly involved the liver (20%) and lung (13%). Median survival from diagnosis of visceral disease was 7.1 mo (95% confidence interval, 5.9-8.3). Survival was affected by the degree of bone involvement at detection of visceral disease, varying from 6.1 mo in men with more than six bone metastases to 18.2 mo in men with no bone metastases (p=0.001). Heterogeneity was noted in clinical phenotypes and prostate-specific antigen trends at development of visceral metastases. Visceral metastases are now more commonly detected in men with CRPC, likely due to the introduction of novel survival-prolonging treatments.

  10. Polycomb-mediated disruption of an androgen receptor feedback loop drives castration-resistant prostate cancer

    PubMed Central

    Fong, Ka-wing; Zhao, Jonathan C.; Kim, Jung; Li, Shangze; Yang, Yeqing Angela; Song, Bing; Rittie, Laure; Hu, Ming; Yang, Ximing; Perbal, Bernard; Yu, Jindan

    2016-01-01

    The lethal phenotype of castration-resistant prostate cancer (CRPC) is generally caused by augmented signaling from the androgen receptor (AR). Here we report that the AR-repressed gene CCN3/NOV inhibits AR signaling and acts in a negative feedback loop to block AR function. Mechanistically, a cytoplasmic form of CCN3 interacted with the AR N-terminal domain to sequester AR in the cytoplasm of prostate cancer cells, thereby reducing AR transcriptional activity and inhibiting cell growth. However, constitutive repression of CCN3 by the Polycomb Group Protein EZH2 disrupted this negative feedback loop in both CRPC and enzalutamide-resistant prostate cancer cells. Notably, restoring CCN3 was sufficient to effectively abolish CPRC cell growth in vitro and in vivo. Taken together, our findings establish CCN3 as a pivotal regulator of AR signaling and prostate cancer progression and they establish a functional intersection between Polycomb and AR signaling in CRPC. PMID:27815387

  11. Activity and safety of ODM-201 in patients with progressive metastatic castration-resistant prostate cancer (ARADES): an open-label phase 1 dose-escalation and randomised phase 2 dose expansion trial.

    PubMed

    Fizazi, Karim; Massard, Christophe; Bono, Petri; Jones, Robert; Kataja, Vesa; James, Nicholas; Garcia, Jorge A; Protheroe, Andrew; Tammela, Teuvo L; Elliott, Tony; Mattila, Leena; Aspegren, John; Vuorela, Annamari; Langmuir, Peter; Mustonen, Mika

    2014-08-01

    ODM-201 is a novel androgen receptor (AR) inhibitor designed to block the growth of prostate cancer cells through high-affinity binding to the AR and inhibition of AR nuclear translocation. This trial assessed ODM-201's safety, pharmacokinetics, and activity in men with metastatic castration-resistant prostate cancer. The ARADES trial is an open-label phase 1-2 trial undertaken in 23 hospitals across Europe and USA with ongoing long-term follow-up. Men with progressive metastatic castration-resistant prostate cancer, who had castrate concentrations of testosterone and an Eastern Cooperative Oncology Group score of 0-1 were enrolled. In the phase 1 part of the trial, patients were given oral ODM-201 at a starting daily dose of 200 mg, which was increased to 400 mg, 600 mg, 1000 mg, 1400 mg, and 1800 mg. In phase 2, patients were randomly assigned centrally and stratified by previous chemotherapy and treatment with CPY17 inhibitors, to receive one of three daily doses of ODM-201 (200 mg, 400 mg, and 1400 mg). The primary endpoint in phase 1 was safety and tolerability, whereas in phase 2 it was the proportion of patients with a PSA response (50% or greater decrease in serum PSA) at week 12. All analyses included patients who had received at least one dose of ODM-201. This trial is registered with ClinicalTrials.gov, number NCT01317641, and NCT01429064 for the follow-up after 12 weeks. We enrolled patients between April 5, 2011, and March 12, 2013. In phase 1, 24 patients were enrolled to six sequential cohorts of three to six patients and received a daily dose of ODM-201, 200-1800 mg. No dose-limiting toxic effects were reported and the maximum tolerated dose was not reached. In phase 1, three patients reported eight adverse events of grade 3 (fracture, muscle injury, laceration, paralytic ileus, pain, presyncope, urinary retention, and vomiting) and one patient had a grade 4 adverse event (lymphoedema). None of the grade 3-4 adverse events were deemed to be related

  12. EPI-001, A Compound Active against Castration-Resistant Prostate Cancer, Targets Transactivation Unit 5 of the Androgen Receptor.

    PubMed

    De Mol, Eva; Fenwick, R Bryn; Phang, Christopher T W; Buzón, Victor; Szulc, Elzbieta; de la Fuente, Alex; Escobedo, Albert; García, Jesús; Bertoncini, Carlos W; Estébanez-Perpiñá, Eva; McEwan, Iain J; Riera, Antoni; Salvatella, Xavier

    2016-09-16

    Castration-resistant prostate cancer is the lethal condition suffered by prostate cancer patients that become refractory to androgen deprivation therapy. EPI-001 is a recently identified compound active against this condition that modulates the activity of the androgen receptor, a nuclear receptor that is essential for disease progression. The mechanism by which this compound exerts its inhibitory activity is however not yet fully understood. Here we show, by using high resolution solution nuclear magnetic resonance spectroscopy, that EPI-001 selectively interacts with a partially folded region of the transactivation domain of the androgen receptor, known as transactivation unit 5, that is key for the ability of prostate cells to proliferate in the absence of androgens, a distinctive feature of castration-resistant prostate cancer. Our results can contribute to the development of more potent and less toxic novel androgen receptor antagonists for treating this disease.

  13. EPI-001, a compound active against castration-resistant prostate cancer, targets transactivation unit 5 of the androgen receptor

    PubMed Central

    De Mol, Eva; Fenwick, R. Bryn; Phang, Christopher T. W.; Buzón, Victor; Szulc, Elzbieta; de la Fuente, Alex; Escobedo, Albert; García, Jesús; Bertoncini, Carlos W.; Estébanez-Perpiñá, Eva; McEwan, Iain J.; Riera, Antoni; Salvatella, Xavier

    2016-01-01

    Castration-resistant prostate cancer is the lethal condition suffered by prostate cancer patients that become refractory to androgen deprivation therapy. EPI-001 is a recently identified compound active against this condition that modulates the activity of the androgen receptor, a nuclear receptor that is essential for disease progression. The mechanism by which this compound exerts its inhibitory activity is however not yet fully understood. Here we show, by using high resolution solution nuclear magnetic resonance spectroscopy, that EPI-001 selectively interacts with a partially folded region of the transactivation domain of the androgen receptor, known as transactivation unit 5, that is key for the ability of prostate cells to proliferate in the absence of androgens, a distinctive feature of castration-resistant prostate cancer. Our results can contribute to the development of more potent and less toxic novel androgen receptor antagonists for treating this disease. PMID:27356095

  14. [Strategy in advanced castration-resistant prostate cancer].

    PubMed

    Gross-Goupil, Marine; Roca, Sophie; Pasticier, Gilles; Ravaud, Alain

    2012-07-01

    If androgen deprivation, chemical with LH-RH analogs or surgical with bilateral orchiectomy, still remains the stone edge of treatment of prostate cancer, in the metastatic setting, this hormonosensitivity, most of the time long, finally move on in hormonal-failure. If rare changes in the therapeutic strategy have been achieved in this setting since 2004 and the arrival of docetaxel, it is the global perception of the disease that has been modified and the definition of one specific entity: the castrate-resistant prostate cancer. This new definition and the changes of design and end-points of clinical trials testing new agents with strong recruitment during the past years have conducted to a real revolution in the management of castrate-refractory prostate cancer. The place of secondary hormonal manipulations, such as withdrawal of the anti-androgen, oestrogen or ketoconazole, still exists for a selected group of patients. In case of aggressive disease and symptoms, chemotherapy should be selected, docetaxel, in a three weeks schedule, and may be combined with Estracyt. It is time to consider the revolution of the post-chemotherapy setting with the arrival of two new drugs ; a cytotoxic one, the cabazitaxel and hormonal for the second one, the abiraterone acetate. The place of the immunotherapy with the sipuleucel-T may be more difficult to precise, especially in Europe, even if it has been finally indicated in the United States in the metastatic setting. Concerning bone metastasis, zoledronic acid was during a long time the only bone-targeted agent, effective in reducing the incidence of skeletal related events, and was recently exceeded by the denosumab, an anti-RANK ligand. Finally, let us hope that other changes will be achieved in the near future, with the cabazitaxel-docetaxel confrontation in the first-line setting, and the introduction of the abiraterone acetate before chemotherapy with docetaxel, already tested in ongoing trials.

  15. PRKAR2B plays an oncogenic role in the castration-resistant prostate cancer

    PubMed Central

    Sha, Jianjun; Xue, Wei; Dong, Baijun; Pan, Jiahua; WU, Xiaorong; Li, Dong; Liu, Dongming; Huang, Yiran

    2017-01-01

    Castration-resistant prostate cancer (CRPC) is an advanced form of prostate cancer. Despite some progresses have been made, the mechanism of CRPC development is still largely unknown, including the genes involved in its development have not been well defined. Here, we identifiedPRKAR2B to be a gene over-expressingin castration-resistant prostate cancer by analyzing the different online databases. Followed functional validation experiments showed that PRKAR2B promoted CRPC cell proliferation and invasion, and inhibited CRPC cell apoptosis. Whole genome transcriptome and GO enrichment analyses of the knock-down of PRKAR2B in CRPC cells showed that PRKAR2B mainly accelerated cell cycle biological process and modulated multiple cell cycle genes, such as CCNB1, MCM2, PLK1 and AURKB. Our study firstly identified PRKAR2B as a novel oncogenic gene involved in CRPC development and suggested it is a promising target for the future investigation and the treatment of CRPC. PMID:28008150

  16. Targeting Met and VEGFR Axis in Metastatic Castration-Resistant Prostate Cancer: 'Game Over'?

    PubMed

    Modena, Alessandra; Massari, Francesco; Ciccarese, Chiara; Brunelli, Matteo; Santoni, Matteo; Montironi, Rodolfo; Martignoni, Guido; Tortora, Giampaolo

    2016-08-01

    Despite recent advances that have been made in the therapeutic landscape of metastatic castration-resistant prostate cancer (mCRPC), effective management of bone metastases remains a key goal not yet reached. The receptor tyrosine kinase MET and the vascular endothelial growth factor receptor (VEGFR) seem to play an important role in prostate cancer progression and pathological bone turnover, representing potential targets for improving clinical outcomes in mCRPC. Studies evaluating agents that target one or both these pathways have demonstrated modest activity but no improvement in overall survival. Nevertheless, this therapeutic strategy seems to still be a promising and engaging area of prostate cancer research and the interest in better understanding the MET/VEGFR axis and the mechanism of action of these inhibitors is growing. This review describes the rationale for targeting MET and VEGFR pathway in mCRPC and provides the clinical data available to date and an update on ongoing trials.

  17. Targeting Cancer Stem Cells in Castration-Resistant Prostate Cancer.

    PubMed

    Yun, Eun-Jin; Zhou, Jiancheng; Lin, Chun-Jung; Hernandez, Elizabeth; Fazli, Ladan; Gleave, Martin; Hsieh, Jer-Tsong

    2016-02-01

    Clinical evidence suggests increased cancer stem cells (CSCs) in a tumor mass may contribute to the failure of conventional therapies because CSCs seem to be more resistant than differentiated tumor cells. Thus, unveiling the mechanism regulating CSCs and candidate target molecules will provide new strategy to cure the patients. The stem-like cell properties were determined by a prostasphere assay and dye exclusion assay. To find critical stem cell marker and reveal regulation mechanism, basic biochemical and molecular biologic methods, such as quantitative real-time PCR, Western blot, reporter gene assay, and chromatin immunoprecipitation assay, were used. In addition, to determine the effect of combination therapy targeting both CSCs and its progeny, in vitro MTT assay and in vivo xenograft model was used. We demonstrate immortalized normal human prostate epithelial cells, appeared nontumorigenic in vivo, become tumorigenic, and acquire stem cell phenotype after knocking down a tumor suppressor gene. Also, those stem-like cells increase chemoresistance to conventional anticancer reagent. Mechanistically, we unveil that Wnt signaling is a key pathway regulating well-known stem cell marker CD44 by directly interacting to the promoter. Thus, by targeting CSCs using Wnt inhibitors synergistically enhances the efficacy of conventional drugs. Furthermore, the in vivo mouse model bearing xenografts showed a robust inhibition of tumor growth after combination therapy. Overall, this study provides strong evidence of CSC in castration-resistant prostate cancer. This new combination therapy strategy targeting CSC could significantly enhance therapeutic efficacy of current chemotherapy regimen only targeting non-CSC cells. ©2015 American Association for Cancer Research.

  18. Hormonal therapy and chemotherapy in hormone-naive and castration resistant prostate cancer

    PubMed Central

    Sternberg, Cora N.

    2015-01-01

    The management of advanced castration resistant prostate cancer (CRPC) has been rapidly changing and is still evolving. In the last years, there has been an increasing knowledge of prostate cancer biology. New therapeutic agents and approaches have been evaluated demonstrating benefits in survival and quality of life in patients with metastatic prostate cancer. PMID:26816835

  19. Sox2 Is an Androgen Receptor-Repressed Gene That Promotes Castration-Resistant Prostate Cancer

    PubMed Central

    Kregel, Steven; Kiriluk, Kyle J.; Rosen, Alex M.; Cai, Yi; Reyes, Edwin E.; Otto, Kristen B.; Tom, Westin; Paner, Gladell P.; Szmulewitz, Russell Z.; Vander Griend, Donald J.

    2013-01-01

    Despite advances in detection and therapy, castration-resistant prostate cancer continues to be a major clinical problem. The aberrant activity of stem cell pathways, and their regulation by the Androgen Receptor (AR), has the potential to provide insight into novel mechanisms and pathways to prevent and treat advanced, castrate-resistant prostate cancers. To this end, we investigated the role of the embryonic stem cell regulator Sox2 [SRY (sex determining region Y)-box 2] in normal and malignant prostate epithelial cells. In the normal prostate, Sox2 is expressed in a portion of basal epithelial cells. Prostate tumors were either Sox2-positive or Sox2-negative, with the percentage of Sox2-positive tumors increasing with Gleason Score and metastases. In the castration-resistant prostate cancer cell line CWR-R1, endogenous expression of Sox2 was repressed by AR signaling, and AR chromatin-IP shows that AR binds the enhancer element within the Sox2 promoter. Likewise, in normal prostate epithelial cells and human embryonic stem cells, increased AR signaling also decreases Sox2 expression. Resistance to the anti-androgen MDV3100 results in a marked increase in Sox2 expression within three prostate cancer cell lines, and in the castration-sensitive LAPC-4 prostate cancer cell line ectopic expression of Sox2 was sufficient to promote castration-resistant tumor formation. Loss of Sox2 expression in the castration-resistant CWR-R1 prostate cancer cell line inhibited cell growth. Up-regulation of Sox2 was not associated with increased CD133 expression but was associated with increased FGF5 (Fibroblast Growth Factor 5) expression. These data propose a model of elevated Sox2 expression due to loss of AR-mediated repression during castration, and consequent castration-resistance via mechanisms not involving induction of canonical embryonic stem cell pathways. PMID:23326489

  20. Therapeutic opportunities for castration-resistant prostate cancer patients with bone metastases.

    PubMed

    Zustovich, Fable; Fabiani, Francesca

    2014-08-01

    Patients with castration-resistant prostate cancer are burdened not only with an unavoidable risk of mortality but also by severe mobility issues. This disease has a high tendency to induce bone metastases with concomitant general suffering, impaired mobility, and reduced self-sufficiency. The treatment of bone pain consists of opioids, nonsteroidal anti-inflammatory drugs, radiopharmaceuticals, and radiotherapy. To date, abiraterone, enzalutamide, zoledronate and denosumab are the only drugs able to delay skeletal events, and docetaxel is the only chemotherapeutic agent able to prolong survival after castration progression. Recently, 5 new drugs have proven to be efficacious in prolonging survival. Sipuleucel-T, cabazitaxel, abiraterone, enzalutamide, and radium-223 have broadened the therapeutic choices, thus changing the clinical paradigm. This review analyzes the data supporting the use of all presently available therapeutic approaches for the management of pain, skeletal events, and survival in castration-resistant prostate cancer patients with bone metastases. Data based on phase 3 trials could identify new approaches depending on patient, disease, and therapy characteristics.

  1. ODM-201: a new-generation androgen receptor inhibitor in castration-resistant prostate cancer

    PubMed Central

    Fizazi, Karim; Albiges, Laurence; Loriot, Yohann; Massard, Christophe

    2015-01-01

    Androgen deprivation therapy is the standard of care for patients with advanced hormone-sensitive prostate cancer. Despite an initial response, most patients progress to castration-resistant prostate cancer (CRPC). The realization that CRPC remains driven by androgen receptor (AR) signaling has formed the basis for a new generation of agents targeting the AR axis. Two of these agents, abiraterone acetate and enzalutamide, have been shown to prolong overall survival in patients with CRPC. Several other AR inhibitors are currently in development for the treatment of CRPC. The present article reviews ODM-201, a new-generation AR inhibitor with a unique molecular structure, in the treatment of CRPC. The design of an ongoing Phase III trial (ARAMIS) of ODM-201 in men with non-metastatic CRPC is also discussed, at a disease stage for which there is currently no approved treatment. PMID:26313416

  2. ODM-201: a new-generation androgen receptor inhibitor in castration-resistant prostate cancer.

    PubMed

    Fizazi, Karim; Albiges, Laurence; Loriot, Yohann; Massard, Christophe

    2015-01-01

    Androgen deprivation therapy is the standard of care for patients with advanced hormone-sensitive prostate cancer. Despite an initial response, most patients progress to castration-resistant prostate cancer (CRPC). The realization that CRPC remains driven by androgen receptor (AR) signaling has formed the basis for a new generation of agents targeting the AR axis. Two of these agents, abiraterone acetate and enzalutamide, have been shown to prolong overall survival in patients with CRPC. Several other AR inhibitors are currently in development for the treatment of CRPC. The present article reviews ODM-201, a new-generation AR inhibitor with a unique molecular structure, in the treatment of CRPC. The design of an ongoing Phase III trial (ARAMIS) of ODM-201 in men with non-metastatic CRPC is also discussed, at a disease stage for which there is currently no approved treatment.

  3. New strategies for medical management of castration-resistant prostate cancer.

    PubMed

    Asmane, Irène; Céraline, Jocelyn; Duclos, Brigitte; Rob, Lynn; Litique, Valère; Barthélémy, Philippe; Bergerat, Jean-Pierre; Dufour, Patrick; Kurtz, Jean-Emmanuel

    2011-01-01

    Although advanced prostate cancer patients respond very well to front-line androgen deprivation, failure to hormonal therapy most often occurs after a median time of 18-24 months. The care of castration-resistant prostate cancer (CRPC) has significantly evolved over the past decade, with the onset of first-line therapy with docetaxel. Although numerous therapy schedules have been investigated alongside docetaxel, in either first-line or salvage therapy, results were dismal. However, CRPC chemotherapy is currently evolving, with, on the one hand, new agents targeting androgen metabolism and, on the other hand, significant progress in chemotherapy drugs, particularly for second-line therapy. The aim of the present review is to describe the current treatments for CRPC chemotherapy alongside their challengers that might shortly become new standards. In this article, we discuss the most recent data from clinical trials to provide the reader with a comprehensive, state-of-the-art overview of CRPC chemotherapy and hormonal therapy.

  4. Targeting the adaptive molecular landscape of castration-resistant prostate cancer

    PubMed Central

    Wyatt, Alexander W; Gleave, Martin E

    2015-01-01

    Castration and androgen receptor (AR) pathway inhibitors induce profound and sustained responses in advanced prostate cancer. However, the inevitable recurrence is associated with reactivation of the AR and progression to a more aggressive phenotype termed castration-resistant prostate cancer (CRPC). AR reactivation can occur directly through genomic modification of the AR gene, or indirectly via co-factor and co-chaperone deregulation. This mechanistic heterogeneity is further complicated by the stress-driven induction of a myriad of overlapping cellular survival pathways. In this review, we describe the heterogeneous and evolvable molecular landscape of CRPC and explore recent successes and failures of therapeutic strategies designed to target AR reactivation and adaptive survival pathways. We also discuss exciting areas of burgeoning anti-tumour research, and their potential to improve the survival and management of patients with CRPC. PMID:25896606

  5. Novel non-AR therapeutic targets in castrate resistant prostate cancer

    PubMed Central

    Toren, Paul J.

    2013-01-01

    Castrate resistant prostate cancer (CRPC) remains a disease with significant morbidity and mortality. The recent approval of abiraterone and enzalutamide highlight the improvements which can be made targeting the androgen receptor (AR) axis. Nonetheless, resistance inevitably develops and there is continued interest in targeting alternate pathways which cause disease resistance and progression. Here, we review non-AR targets in CRPC, with an emphasis on novel agents now in development. This includes therapeutics which target the tumour microenvironment, the bone metastatic environment, microtubules, cellular energetics, angiogenesis, the stress response, survival proteins, intracellular signal transduction, DNA damage repair and dendritic cells. Understanding the hallmarks of prostate cancer resistance in CRPC has led to the identification and development of these new targets. We review the molecular rationale, as well at the clinical experience for each of these different classes of agents which are in clinical development. PMID:26816739

  6. MiR-146-SIAH2-AR Signaling in Castration-Resistant Prostate Cancer

    DTIC Science & Technology

    2015-09-01

    androgen-dependent prostate cancer (ADPC) into CRPC [1]. SIAH2, a ubiquitin ligase was shown to be overexpressed in CRPCs and was recently...APPENDICES: References: 1. Qi, J., et al., The E3 ubiquitin ligase Siah2 contributes to castration-resistant prostate cancer by regulation of androgen

  7. Castration resistance in human prostate cancer is conferred by a frequently occurring androgen receptor splice variant

    PubMed Central

    Sun, Shihua; Sprenger, Cynthia C.T.; Vessella, Robert L.; Haugk, Kathleen; Soriano, Kathryn; Mostaghel, Elahe A.; Page, Stephanie T.; Coleman, Ilsa M.; Nguyen, Holly M.; Sun, Huiying; Nelson, Peter S.; Plymate, Stephen R.

    2010-01-01

    Progression of prostate cancer following castration is associated with increased androgen receptor (AR) expression and signaling despite AR blockade. Recent studies suggest that these activities are due to the generation of constitutively active AR splice variants, but the mechanisms by which these splice variants could mediate such effects are not fully understood. Here we have identified what we believe to be a novel human AR splice variant in which exons 5, 6, and 7 are deleted (ARv567es) and demonstrated that this variant can contribute to cancer progression in human prostate cancer xenograft models in mice following castration. We determined that, in human prostate cancer cell lines, ARv567es functioned as a constitutively active receptor, increased expression of full-length AR (ARfl), and enhanced the transcriptional activity of AR. In human xenografts, human prostate cancer cells transfected with ARv567es cDNA formed tumors that were resistant to castration. Furthermore, the ratio of ARv567es to ARfl expression within the xenografts positively correlated with resistance to castration. Importantly, we also detected ARv567es frequently in human prostate cancer metastases. In summary, these data indicate that constitutively active AR splice variants can contribute to the development of castration-resistant prostate cancers and may serve as biomarkers for patients who are likely to suffer from early recurrence and are candidates for therapies directly targeting the AR rather than ligand. PMID:20644256

  8. Dual-Targeting of AR and Akt Pathways by Berberine in Castration-Resistant Prostate Cancer

    DTIC Science & Technology

    2015-08-01

    Berberine; natural compound; LuCaP86.2; castration resistant prostate cancer; AR splice variants. 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...resistant prostate cancer (CRPC) driven by AR splice variants. 2. Keywords Prostate cancer; androgen receptor; berberine; natural compound; LuCaP86.2...5P20GM103518-10, Louisiana Cancer Research Consortium Fund, Oliver Sartor Prostate Cancer Research Fund, National Natural Science Foundation of China

  9. Predictors of poor response to secondary alternative antiandrogen therapy with flutamide in metastatic castration-resistant prostate cancer.

    PubMed

    Yasui, Masato; Uemura, Koichi; Yoneyama, Shuko; Kawahara, Takashi; Hattori, Yusuke; Teranishi, Jun-Ichi; Inoue, Masahiro; Ohta, Jun-Ichi; Yokomizo, Yumiko; Yao, Masahiro; Uemura, Hiroji; Miyoshi, Yasuhide

    2016-08-17

    In Japan, flutamide had been commonly used as second-line alternative antiandrogen hormonal therapy for metastatic castration-resistant prostate cancer that relapses after initial hormone therapy before new androgen pathway inhibitors became available. In this study, we attempted to identify predictive factors for efficacy of alternative antiandrogen as second-line hormone therapy. We identified consecutive 65 patients with metastatic castration-resistant prostate cancer who were treated with alternative antiandrogen as second-line hormonal therapy (bicalutamide to flutamide). All patients were treated with combined androgen blockade initially. We analyzed correlations between progression-free survival of alternative antiandrogen and clinicopathological characteristics, including patients' ages, initial prostate-specific antigen levels, prostate-specific antigen levels at flutamide induction, Gleason scores, T stage, N stage, extent of disease grades on bone scan and previous duration of prostate cancer response to combined androgen blockade. In univariate analysis, T stage, N stage and previous duration of response to combined androgen blockade were correlated with shorter progression-free survival. We found four significant risk factors for shorter progression-free survival in multivariate analysis: initial prostate-specific antigen level, clinical N stage, extent of disease grades and previous duration of response to combined androgen blockade. Initial prostate-specific antigen, N stage, extent of disease grades on bone scan and previous duration of response to combined androgen blockade were the significant predictors for efficacy of alternative antiandrogen as second-line hormone therapy in patients with metastatic castration-resistant prostate cancer. These findings might support that decision-making of when to start the new androgen receptor pathway inhibitors. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions

  10. The Role of Testosterone in the Treatment of Castration-Resistant Prostate Cancer.

    PubMed

    Drazer, Michael W; Stadler, Walter M

    Most men with metastatic prostate cancer who are treated with androgen deprivation therapy will eventually develop castration-resistant disease. In this review, we examine the molecular mechanisms that constitute castration resistance and how these processes may be exploited using testosterone-based therapies. We detail how the utilization of superphysiologic doses of testosterone at regular intervals, followed by a rapid clearance of testosterone through continued chemical castration, also known as bipolar androgen therapy, offers an especially promising therapeutic approach. We investigate the historical basis for this modality, detail recent early-phase clinical trials that have demonstrated the feasibility and efficacy of this treatment, and describe an ongoing clinical trial comparing this modality to a currently accepted standard of care, enzalutamide, for castration-resistant prostate cancer. Finally, we explore how this treatment modality will continue to be refined in the future.

  11. Management of Docetaxel Failures in Metastatic Castrate-Resistant Prostate Cancer

    PubMed Central

    Pal, Sumanta K.; Lewis, Brian; Sartor, Oliver

    2013-01-01

    SYNOPSIS The treatment of metastatic castration resistant prostate cancer (mCRPC) has evolved markedly since the approval of docetaxel-based therapy in 2004. Since that time, 3 distinct agents have gained approval for use in the mCRPC setting, namely sipuleucel-T, cabazitaxel and abiraterone. Even more recently, phase III trials have demonstrated a survival benefit in association with the agents MDV-3100 and radium-223, and FDA approval is anticipated for both of these agents. Although these changes undoubtedly represent progress for the patient with mCRPC, for the practicing physician there is the additional challenge of determining the optimal sequencing for each of these agents. This dilemma is particularly relevant to the post-docetaxel setting, where the indication for several of these agents overlap. Herein, we provide the physician with detailed background on the efficacy and safety of these agents so as to provide a framework for their use in the clinic. PMID:23084533

  12. Mechanisms of acquired resistance to androgen receptor targeting drugs in castration resistant prostate cancer

    PubMed Central

    Chism, David D.; De Silva, Dinuka; Whang, Young E.

    2014-01-01

    After initial response to androgen receptor targeting drugs abiraterone or enzalutamide, most patients develop progressive disease and therefore, castration resistant prostate cancer (CRPC) remains a terminal disease. Multiple mechanisms underlying acquired resistance have been postulated. Intratumoral androgen synthesis may resume after abiraterone treatment. A point mutation in the ligand binding domain of androgen receptor may confer resistance to enzalutamide. Emergence of androgen receptor splice variants lacking the ligand binding domain may mediate resistance to abiraterone and enzalutamide. Steroid receptors such as glucocorticoid receptor may substitute for androgen receptor. Drugs with novel mechanisms of action or combination therapy, along with biomarkers for patient selection, may be needed to improve the therapy of CRPC. PMID:24927631

  13. Neuroendocrine differentiation in castration-resistant prostate cancer: A case report.

    PubMed

    Priftakis, Dimitrios; Kritikos, Nikolaos; Stavrinides, Stavros; Kleanthous, Stefanos; Baziotis, Nikolaos

    2015-11-01

    The most common type of prostate cancer is acinar adenocarcinoma, which is androgen-dependent and, therefore, treated with chemical or surgical castration and androgen receptor inhibition. However, the disease usually progresses to castration-resistant prostate cancer (CRPC). A neuroendocrine pattern is frequently observed in the cellular composition of CRPC, which is considered to emerge as an effect of androgen deprivation therapy. This is the case report of a 69-year-old patient with prostate adenocarcinoma, who, after an initial period of disease control with radiotherapy and antiandrogens, was diagnosed with CRPC with high levels of prostate-specific antigen (PSA), unresponsive to androgen inhibition, with accompanying lung and osseous metastases. Bronchial biopsy of the lung metastasis revealed infiltration by non-small-cell adenocarcinoma of prostatic origin with neuroendocrine characteristics. On somatostatin receptor scintigraphy with (99m)Tc-octreotide, there was high uptake by almost all known lung and osseous metastases. The patient was subsequently treated with a combination of docetaxel and octreotide, and a partial response was observed 6 months later, with reduction of the PSA level and the size of the lung metastasis. The aim of the present study was to provide a clinical example of the previously demonstrated, in vitro and in vivo, synergistic antitumor activities of docetaxel and octreotide in cases of CRPC selected by means of histological confirmation of their neuroendocrine nature and somatostatin receptor scintigraphy.

  14. Dual-Targeting of AR and Akt Pathways by Berberine in Castration-Resistant Prostate Cancer

    DTIC Science & Technology

    2013-08-01

    Berberine in Castration-Resistant Prostate Cancer PRINCIPAL INVESTIGATOR: Haitao Zhang CONTRACTING ORGANIZATION: Tulane University...Resistant Prostate Cancer 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Haitao Zhang 5e. TASK NUMBER...had no adverse effects on normal organs. Since Pten loss or inactivation is common in prostate cancer , these results provide support for the use

  15. CpG-STAT3siRNA for Castration-Resistant Prostate Cancer Therapy

    DTIC Science & Technology

    2013-10-01

    simultaneously target both castration-resistant prostate cancer cells and tumor-associated immune cells, such as myeloid-derived suppressor cells ( MDSCs ...generate potent antitumor immunity, with minimal adverse effects . Body The main goals of this study are: optimization of the CpG(A)-siRNA strategy...for targeting survival signaling in metastatic prostate cancer cells and for breaking immunosuppressive effects of the prostate cancer

  16. Serum biomarkers of bone metabolism in castration resistant prostate cancer patients with skeletal metastases

    USDA-ARS?s Scientific Manuscript database

    Background. Prior studies suggest that elevated markers of bone turnover are prognostic for poor survival in castration resistant prostate cancer (CRPC). The predictive role of these markers relative to bone-targeted therapy is unknown. We prospectively evaluated the prognostic and predictive value ...

  17. Overcoming Autophagy to Induce Apoptosis in Castration-Resistant Prostate Cancer

    DTIC Science & Technology

    2014-10-01

    such as clomipramine and metformin , tumor survival mechanism encountering enzalutamide treatment may be blocked. A much significant reduction of tumor...further enhanced when combined with autophagy modulator like metformin . 15. SUBJECT TERMS prostate cancer, autophagy, therapy, castration-resistant...inhibiting autophagy with clomipramine (CMI) [6, 7] and metformin (Metf) [8-10]. Combination of Enza with saracatinib and autophagy modulators significantly

  18. Bipolar Androgen Therapy: A Paradoxical Approach for the Treatment of Castration-resistant Prostate Cancer.

    PubMed

    Schweizer, Michael T; Antonarakis, Emmanuel S; Denmeade, Samuel R

    2017-09-01

    Bipolar androgen therapy (BAT) is a paradoxical treatment for castrate-resistant prostate cancer whereby testosterone levels are rapidly alternated between supraphysiologic and near-castrate concentrations. Initial studies demonstrated that BAT is safe and produces clinical responses. A trial comparing enzalutamide against BAT is ongoing. Copyright © 2017 European Association of Urology. Published by Elsevier B.V. All rights reserved.

  19. Germline genetic variation in JAK2 as a prognostic marker in castration-resistant prostate cancer.

    PubMed

    Zhang, Ben Y; Riska, Shaun M; Mahoney, Douglas W; Costello, Brian A; Kohli, Rhea; Quevedo, Jorge F; Cerhan, James R; Kohli, Manish

    2017-03-01

    To evaluate the prognostic significance of germline variation in candidate genes in patients with castration-resistant prostate cancer (CRPC). Germline DNA was extracted from peripheral blood mononuclear cells of patients with CRPC enrolled in a clinically annotated registry. Fourteen candidate genes implicated in either initiation or progression of prostate cancer were tagged using single nucleotide polymorphisms (SNPs) from HapMap with a minor allele frequency of >5%. The primary endpoint was overall survival (OS), defined as time from development of CRPC to death. Principal component analysis was used for gene levels tests of significance. For SNP-level results the per allele hazard ratios (HRs) and 95% confidence intervals (CIs) under the additive allele model were estimated using Cox regression, adjusted for age at CRPC and Gleason score (GS). A total of 240 patients with CRPC were genotyped (14 genes; 84 SNPs). The median (range) age of the cohort was 69 (43-93) years. The GS distribution was 55% with GS ≥8, 32% with GS = 7 and 13% with GS <7 or unknown. The median (interquartile range) time from castration resistance to death for the cohort was 2.67 (1.6-4.07) years (144 deaths). At the gene level, a single gene, JAK2 was associated with OS (P < 0.01), and 11 of 18 JAK2 SNPs were individually associated with OS after adjustment for age and GS. A multivariate model consisting of age, GS, rs2149556 (HR 0.67; 95% CI 0.38-1.18) and rs4372063 (HR 2.17; 95% CI 1.25-3.76) was constructed to predict survival in patients with CRPC (concordance of 0.69, P < 3.2 × 10(-9) ). Germline variation in the JAK2 gene was associated with survival in patients with CRPC and warrants further validation as a potential prognostic biomarker. © 2016 The Authors BJU International © 2016 BJU International Published by John Wiley & Sons Ltd.

  20. Targeted BikDD expression kills androgen-dependent and castration-resistant prostate cancer cells

    PubMed Central

    Xie, Xiaoming; Kong, Yanan; Tang, Hailin; Yang, Lu; Hsu, Jennifer L; Hung, Mien-Chie

    2014-01-01

    Targeted gene therapy is a promising approach for treating prostate cancer after the discovery of prostate cancer-specific promoters such as prostate-specific antigen, rat probasin, and human glandular kallikrein. However, these promoters are androgen-dependent, and after castration or androgen ablation therapy, they become much less active or sometimes inactive. Importantly, the disease will inevitably progress from androgen-dependent (ADPC) to castration-resistant prostate cancer (CRPC) at which treatments fail and high mortality ensues. Therefore, it is critical to develop a targeted gene therapy strategy that is effective in both ADPC and CRPC to eradicate recurrent prostate tumors. The human telomerase reverse transcriptase-VP16-Gal4-WPRE integrated systemic amplifier composite (T-VISA) vector we previously developed which targets transgene expression in ovarian and breast cancer is also active in prostate cancer. To further improve its effectiveness based on androgen response in ADPC progression, the ARR2 element (two copies of androgen response region from rat probasin promoter) was incorporated into T-VISA to produce AT-VISA. Under androgen analog (R1881) stimulation, the activity of AT-VISA was increased to a level greater than or comparable to the cytomegalovirus (CMV) promoter in ADPC and CRPC cells, respectively. Importantly, AT-VISA demonstrated little or no expression in normal cells. Systemic administration of AT-VISA-BikDD encapsulated in liposomes repressed prostate tumor growth and prolonged mouse survival in orthotopic animal models as well as in the transgenic adenocarcinoma mouse prostate model, indicating that AT-VISA-BikDD has therapeutic potential to treat ADPC and CRPC safely and effectively in preclinical setting. PMID:24785255

  1. Crosstalk of the Androgen Receptor with Transcriptional Collaborators: Potential Therapeutic Targets for Castration-Resistant Prostate Cancer

    PubMed Central

    Obinata, Daisuke; Takayama, Kenichi; Takahashi, Satoru; Inoue, Satoshi

    2017-01-01

    Prostate cancer is the second leading cause of death from cancer among males in Western countries. It is also the most commonly diagnosed male cancer in Japan. The progression of prostate cancer is mainly influenced by androgens and the androgen receptor (AR). Androgen deprivation therapy is an established therapy for advanced prostate cancer; however, prostate cancers frequently develop resistance to low testosterone levels and progress to the fatal stage called castration-resistant prostate cancer (CRPC). Surprisingly, AR and the AR signaling pathway are still activated in most CRPC cases. To overcome this problem, abiraterone acetate and enzalutamide were introduced for the treatment of CRPC. Despite the impact of these drugs on prolonged survival, CRPC acquires further resistance to keep the AR pathway activated. Functional molecular studies have shown that some of the AR collaborative transcription factors (TFs), including octamer transcription factor (OCT1), GATA binding protein 2 (GATA2) and forkhead box A1 (FOXA1), still stimulate AR activity in the castration-resistant state. Therefore, elucidating the crosstalk between the AR and collaborative TFs on the AR pathway is critical for developing new strategies for the treatment of CRPC. Recently, many compounds targeting this pathway have been developed for treating CRPC. In this review, we summarize the AR signaling pathway in terms of AR collaborators and focus on pyrrole-imidazole (PI) polyamide as a candidate compound for the treatment of prostate cancer. PMID:28264478

  2. Polycomb-Mediated Disruption of an Androgen Receptor Feedback Loop Drives Castration-Resistant Prostate Cancer.

    PubMed

    Fong, Ka-Wing; Zhao, Jonathan C; Kim, Jung; Li, Shangze; Yang, Yeqing A; Song, Bing; Rittie, Laure; Hu, Ming; Yang, Ximing; Perbal, Bernard; Yu, Jindan

    2017-01-15

    The lethal phenotype of castration-resistant prostate cancer (CRPC) is generally caused by augmented signaling from the androgen receptor (AR). Here, we report that the AR-repressed gene CCN3/NOV inhibits AR signaling and acts in a negative feedback loop to block AR function. Mechanistically, a cytoplasmic form of CCN3 interacted with the AR N-terminal domain to sequester AR in the cytoplasm of prostate cancer cells, thereby reducing AR transcriptional activity and inhibiting cell growth. However, constitutive repression of CCN3 by the Polycomb group protein EZH2 disrupted this negative feedback loop in both CRPC and enzalutamide-resistant prostate cancer cells. Notably, restoring CCN3 was sufficient to effectively reduce CPRC cell proliferation in vitro and to abolish xenograft tumor growth in vivo Taken together, our findings establish CCN3 as a pivotal regulator of AR signaling and prostate cancer progression and suggest a functional intersection between Polycomb and AR signaling in CRPC. Cancer Res; 77(2); 412-22. ©2016 AACR. ©2016 American Association for Cancer Research.

  3. Enzalutamide: a review of its use in metastatic, castration-resistant prostate cancer.

    PubMed

    Sanford, Mark

    2013-10-01

    Enzalutamide (MDV3100, XTANDI(®)) is an androgen receptor inhibitor that is indicated for the treatment of metastatic, castration-resistant, prostate cancer (mCRPC) that has progressed despite treatment with docetaxel. This article reviews the pharmacology, efficacy and tolerability of enzalutamide relevant to this indication. In a randomized, double-blind, placebo-controlled, multinational, phase III trial in patients with mCRPC progressing after docetaxel therapy, enzalutamide significantly prolonged overall survival (OS), delayed prostate specific antigen progression and prolonged radiographic progression-free survival and time to the first skeletal event. The median OS was 18.4 months in the enzalutamide group and 13.6 months in the placebo group, which represents a 37 % reduction in the mortality risk in the enzalutamide group. Enzalutamide was also associated with significant benefits in health-related quality of life and in pain palliation. Enzalutamide was generally as well tolerated as placebo during the trial, with most adverse events at a mild or moderate level of severity. Enzalutamide carries a small increased risk of seizures that appears to be dose-dependent. Enzalutamide is an efficacious and well tolerated treatment for this severe, rapidly progressive disease.

  4. Raman spectroscopy, a potential tool in diagnosis and prognosis of castration-resistant prostate cancer

    NASA Astrophysics Data System (ADS)

    Wang, Lei; He, Dalin; Zeng, Jin; Guan, Zhenfeng; Dang, Qiang; Wang, Xinyang; Wang, Jun; Huang, Liqing; Cao, Peilong; Zhang, Guanjun; Hsieh, JerTong; Fan, Jinhai

    2013-08-01

    Purpose: We evaluated the feasibility of Raman spectroscopy (RS) in diagnosis and prognosis of castration-resistant prostate cancer (CRPC) in patients with prostate cancer (PC). Materials and methods: Raman spectra are detected from PC cell lines (LNCaP and C4-2) and tissues using a Labram HR 800 RS. Then, principal component analysis (PCA) and support vector machine (SVM) are applied for prediction. A leave-one-out cross-validation is used to train and test the SVM. Results: There are 50 qualified patients, including 33 with androgen-dependent prostate cancer (ADPC) and 17 with CRPC. The spectral changes at 1126, 1170, 1315 to 1338, and 1447 cm-1 between CRPC and ADPC are detected in both cells and tissues models, which are assigned to specific amino acids and DNA. PCA/SVM algorithm provided a sensitivity of 88.2% and a specificity of 87.9% for diagnosing CRPC tissues. Furthermore, 14 patients with ADPC progressed to CRPC within 12 months. These patients are separated into two groups depending on whether their cancers progressed to CRPC within 12 months. PCA/SVM could differentiate these two groups with a sensitivity of 85.7% and a specificity of 88.9%. Conclusions: RS has the potential in diagnosis and prognosis of CRPC in clinical practice.

  5. Castration resistant prostate cancer (CRPC): state of the art, perspectives and new challenges.

    PubMed

    Massari, Francesco; Maines, Francesca; Modena, Alessandra; Brunelli, Matteo; Bria, Emilio; Artibani, Walter; Martignoni, Guido; Tortora, Giampaolo

    2013-07-01

    The rapid approval of several novel agents has given prostate cancer patients and their treating physicians many new and effective therapeutic options. Four new medical therapies were recently approved on the basis of prolonged overall survival in castration-resistant prostate cancer (CRPC) patients: sipuleucel-T, cabazitaxel, abiraterone acetate and MDV3100. Additionally, there are several other promising prostate cancer agents in late-stage development, including PROSTVAC-VF, orteronel and radium-223 chloride, each with a novel mechanism of action. The treatment paradigm for these patients is rapidly evolving, with future study needed to define the optimal sequencing and potential combinations of these new agents. In this review, we discuss the recent progress in understanding the biology of this disease and examining the development of a variety of new agents with promising activity and a favorable toxicity profile, that have been investigated in the setting of hormonal, cytotoxic, immune and targeted therapy. In this new therapeutic setting of CRPC, clinicians will have an opportunity to balance benefits and harms of these new agents in an individual context.

  6. Inhibition of Plk1 represses androgen signaling pathway in castration-resistant prostate cancer

    PubMed Central

    Zhang, Zhe; Chen, Long; Wang, Hexiang; Ahmad, Nihal; Liu, Xiaoqi

    2015-01-01

    Prostate cancer (PCa) is the second leading cause of cancer-related death in males in the United States. Majority of prostate cancers are originally androgen-dependent and sensitive to androgen-deprivation therapy (ADT), however, most of them eventually relapse and progress into incurable castration-resistant prostate cancer (CRPC). Of note, the activity of androgen receptor (AR) is still required in CRPC stage. The mitotic kinase polo-like kinase 1 (Plk1) is significantly elevated in PCa and its expression correlates with tumor grade. In this study, we assess the effects of Plk1 on AR signaling in both androgen-dependent and androgen-independent PCa cells. We demonstrate that the expression level of Plk1 correlated with tumorigenicity and that inhibition of Plk1 caused reduction of AR expression and AR activity. Furthermore, Plk1 inhibitor BI2536 down-regulated SREBP-dependent expression of enzymes involved in androgen biosynthesis. Of interest, Plk1 level was also reduced when AR activity was inhibited by the antagonist MDV3100. Finally, we show that BI2536 treatment significantly inhibited tumor growth in LNCaP CRPC xenografts. Overall, our data support the concept that Plk1 inhibitor such as BI2536 prevents AR signaling pathway and might have therapeutic potential for CRPC patients. PMID:25927139

  7. Ipilimumab versus placebo after radiotherapy in patients with metastatic castration-resistant prostate cancer that had progressed after docetaxel chemotherapy (CA184-043): a multicentre, randomised, double-blind, phase 3 trial

    PubMed Central

    Kwon, Eugene D; Drake, Charles G; Scher, Howard I; Fizazi, Karim; Bossi, Alberto; van den Eertwegh, Alfons J M; Krainer, Michael; Houede, Nadine; Santos, Ricardo; Mahammedi, Hakim; Ng, Siobhan; Maio, Michele; Franke, Fabio A; Sundar, Santhanam; Agarwal, Neeraj; Bergman, Andries M; Ciuleanu, Tudor E; Korbenfeld, Ernesto; Sengeløv, Lisa; Hansen, Steinbjorn; Logothetis, Christopher; Beer, Tomasz M; McHenry, M Brent; Gagnier, Paul; Liu, David; Gerritsen, Winald R

    2015-01-01

    Summary Background Ipilimumab is a fully human monoclonal antibody that binds cytotoxic T-lymphocyte antigen 4 to enhance antitumour immunity. Our aim was to assess the use of ipilimumab after radiotherapy in patients with metastatic castration-resistant prostate cancer that progressed after docetaxel chemotherapy. Methods We did a multicentre, randomised, double-blind, phase 3 trial in which men with at least one bone metastasis from castration-resistant prostate cancer that had progressed after docetaxel treatment were randomly assigned in a 1:1 ratio to receive bone-directed radiotherapy (8 Gy in one fraction) followed by either ipilimumab 10 mg/kg or placebo every 3 weeks for up to four doses. Non-progressing patients could continue to receive ipilimumab at 10 mg/kg or placebo as maintenance therapy every 3 months until disease progression, unacceptable toxic effect, or death. Patients were randomly assigned to either treatment group via a minimisation algorithm, and stratified by Eastern Cooperative Oncology Group performance status, alkaline phosphatase concentration, haemoglobin concentration, and investigator site. Patients and investigators were masked to treatment allocation. The primary endpoint was overall survival, assessed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT00861614. Findings From May 26, 2009, to Feb 15, 2012, 799 patients were randomly assigned (399 to ipilimumab and 400 to placebo), all of whom were included in the intention-to-treat analysis. Median overall survival was 11·2 months (95% CI 9·5–12·7) with ipilimumab and 10·0 months (8·3–11·0) with placebo (hazard ratio [HR] 0·85, 0·72–1·00; p=0·053). However, the assessment of the proportional hazards assumption showed that it was violated (p=0·0031). A piecewise hazard model showed that the HR changed over time: the HR for 0–5 months was 1·46 (95% CI 1·10–1·95), for 5–12 months was 0·65 (0·50–0·85), and

  8. Biologic and Clinical Significance of Androgen Receptor Variants in Castration Resistant Prostate Cancer

    PubMed Central

    Ware, Kathryn E; Garcia-Blanco, Mariano A; Armstrong, Andrew J; Dehm, Scott M.

    2014-01-01

    As prostate cancer progresses to the lethal castration resistant and metastatic form, genetic and epigenetic adaptation, clonal selection, and evolution of the tumor microenvironment contribute to the emergence of unique biologic characteristics under the selective pressure of external stresses. These stresses include the therapies applied in the clinic or laboratory and the exposures of cancers to hormonal, paracrine, or autocrine stimuli in the context of the tumor micro- and macro-environment. The androgen receptor (AR) is a key gene involved in prostate cancer etiology and oncogenesis, including disease development, progression, response to initial hormonal therapies, and subsequent resistance to hormonal therapies. Alterations in the AR signaling pathway have been observed in certain selection contexts and contribute to the resistance to agents that target hormonal regulation of the AR, including standard androgen deprivation therapy (ADT), anti-androgens such as enzalutamide, and androgen synthesis inhibition with abiraterone acetate. One such resistance mechanism is the synthesis of constitutively active AR variants lacking the canonical ligand binding domain. This review focuses on the etiology, characterization, biologic properties, and emerging data contributing to the clinical characteristics of AR variants, and suggests approaches to full-length AR and AR variant biomarker validation, assessment, and systemic targeting in the clinic. PMID:24859991

  9. Abiraterone in the management of castration-resistant prostate cancer prior to chemotherapy.

    PubMed

    Gartrell, Benjamin A; Saad, Fred

    2015-08-01

    The treatment armamentarium for metastatic castration-resistant prostate cancer (mCRPC) has increased significantly over the past several years. Approved drugs associated with improved survival include androgen pathway-targeted agents (abiraterone acetate and enzalutamide), chemotherapeutics (docetaxel and cabazitaxel), an autologous vaccine (sipuleucel-T) and a radiopharmaceutical (radium-223). Abiraterone acetate, a prodrug of abiraterone, inhibits the CYP17A enzyme, a critical enzyme in androgen biosynthesis. Abiraterone has regulatory approval in mCRPC in both chemotherapy-naïve patients and in the post-docetaxel setting based on results from two randomized phase III studies. In the COU-AA-302 trial, abiraterone demonstrated significant improvement in the coprimary endpoints of radiographic progression-free survival and overall survival, as well as in a number of secondary endpoints including time until initiation of chemotherapy, time until opiate use for cancer-related pain, prostate-specific antigen progression-free survival and decline in performance status. Abiraterone is well-tolerated, although adverse events associated with this agent include abnormalities in liver function testing and mineralocorticoid-associated adverse events. This review evaluates the use of abiraterone in mCRPC prior to the use of chemotherapy.

  10. Enzalutamide Versus Bicalutamide in Castration-Resistant Prostate Cancer: The STRIVE Trial.

    PubMed

    Penson, David F; Armstrong, Andrew J; Concepcion, Raoul; Agarwal, Neeraj; Olsson, Carl; Karsh, Lawrence; Dunshee, Curtis; Wang, Fong; Wu, Kenneth; Krivoshik, Andrew; Phung, De; Higano, Celestia S

    2016-06-20

    Enzalutamide, a potent oral androgen receptor inhibitor, improves survival in men with metastatic castration-resistant prostate cancer (CRPC) before and after chemotherapy. Bicalutamide, a nonsteroidal antiandrogen, is widely used to treat men with nonmetastatic or metastatic CRPC. The efficacy and safety of these drugs were compared in this randomized, double-blind, phase II study of men with CRPC. A total of 396 men with nonmetastatic (n = 139) or metastatic (n = 257) CRPC were randomly assigned to enzalutamide 160 mg per day (n = 198) or bicalutamide 50 mg per day (n = 198). Androgen deprivation therapy was continued in both arms. The primary end point was progression-free survival (PFS). Enzalutamide reduced the risk of progression or death by 76% compared with bicalutamide (hazard ratio [HR], 0.24; 95% CI, 0.18 to 0.32; P < .001). Median PFS was 19.4 months with enzalutamide versus 5.7 months with bicalutamide. Enzalutamide resulted in significant improvements in all key secondary end points: time to prostate-specific antigen progression (HR, 0.19; 95% CI, 0.14 to 0.26; P < .001); proportion of patients with a ≥ 50% prostate-specific antigen response (81% v 31%; P < .001); and radiographic PFS in metastatic patients (HR, 0.32; 95% CI, 0.21 to 0.50; P < .001). Beneficial effects with enzalutamide were observed in both nonmetastatic and metastatic subgroups. The observed adverse event profile was consistent with that from phase III enzalutamide trials. Enzalutamide significantly reduced risk of prostate cancer progression or death compared with bicalutamide in patients with nonmetastatic or metastatic CRPC. © 2016 by American Society of Clinical Oncology.

  11. A Pharmacokinetic/Pharmacodynamic Study of the Glucocorticoid Receptor Antagonist Mifepristone Combined with Enzalutamide in Castrate-Resistant Prostate Cancer

    DTIC Science & Technology

    2014-12-01

    combination of mifepristone and enzalutamide has been well tolerated with no dose limiting toxicities . The current cohort has dose- escalated the...Pharmacodynamic Study of the Glucocorticoid Receptor Antagonist Mifepristone Combined with Enzalutamide in Castrate-Resistant Prostate Cancer...Antagonist Mifepristone Combined with Enzalutamide in Castrate-Resistant Prostate Cancer 5b. GRANT NUMBER W81XWH-14-1-0021 5c. PROGRAM ELEMENT

  12. Therapeutic Targeting of BET Bromodomain Proteins in Castration-Resistant Prostate Cancer

    PubMed Central

    Asangani, Irfan A.; Dommeti, Vijaya L.; Wang, Xiaoju; Malik, Rohit; Cieslik, Marcin; Yang, Rendong; Escara-Wilke, June; Wilder-Romans, Kari; Dhanireddy, Sudheer; Engelke, Carl; Iyer, Mathew K.; Jing, Xiaojun; Wu, Yi-Mi; Cao, Xuhong; Qin, Zhaohui S.; Wang, Shaomeng; Feng, Felix Y.; Chinnaiyan, Arul M.

    2014-01-01

    Men who develop metastatic castration-resistant prostate cancer (CRPC) invariably succumb to the disease. The development and progression to CRPC following androgen ablation therapy is predominantly driven by unregulated androgen receptor (AR) signaling1-3. Despite the success of recently approved therapies targeting AR signaling such as abiraterone4-6 and second generation anti-androgens MDV3100 (enzalutamide)7,8, durable responses are limited, presumably due to acquired resistance. Recently JQ1 and I-BET, two selective small molecule inhibitors that target the amino-terminal bromodomains of BRD4, have been shown to exhibit anti-proliferative effects in a range of malignancies9-12. Here we show that AR signaling-competent CRPC cell lines are preferentially sensitive to BET bromodomain inhibition. BRD4 physically interacts with the N-terminal domain of AR and can be disrupted by JQ111,13. Like the direct AR antagonist, MDV3100, JQ1 disrupted AR recruitment to target gene loci. In contrast to MDV3100, JQ1 functions downstream of AR, and more potently abrogated BRD4 localization to AR target loci and AR-mediated gene transcription including induction of TMPRSS2-ERG and its oncogenic activity. In vivo, BET bromodomain inhibition was more efficacious than direct AR antagonism in CRPC xenograft models. Taken together, these studies provide a novel epigenetic approach for the concerted blockade of oncogenic drivers in advanced prostate cancer. PMID:24759320

  13. Safety of Abiraterone Acetate in Castration-resistant Prostate Cancer Patients With Concomitant Cardiovascular Risk Factors.

    PubMed

    Procopio, Giuseppe; Grassi, Paolo; Testa, Isabella; Verzoni, Elena; Torri, Valter; Salvioni, Roberto; Valdagni, Riccardo; de Braud, Filippo

    2015-10-01

    The aim of this study was to evaluate the safety profile of abiraterone acetate (AA) in metastatic castration-resistant prostate cancer (mCRPC) men with cardiovascular comorbidity, as little conclusive safety data are available in this patient subset. A retrospective analysis of mCRPC patients with controlled cardiovascular comorbidities, receiving AA 1000 mg administered orally once daily and prednisone 5 mg twice daily, between April 2011 and July 2012, was performed. All clinical and instrumental variables and toxicity data were analyzed by descriptive statistics: mean, standard deviation, minimum and maximum values for continuous variables, and absolute and relative frequencies for categorical variables. A total of 51 mCRPC patients were evaluated. Metastatic sites included the bone (74%), lungs, and liver (26%). All patients were previously treated with at least 2 lines of hormone and 1 docetaxel-based chemotherapy. Preexisting cardiac risk factors included hypertension (41%), cardiac ischemia (12%), arrhythmias (6%), dislipidemia (18%), and hyperglycemia (30%). No grade 3-4 adverse events were observed. Grade 1-2 adverse events included fluid retention (18%), asthenia (15%), and hypertension (16%). Median progression-free survival was 5.1 months (95% confidence interval, 0.5-12). Prostate specific antigen assessment revealed a good overall disease control rate (64%). AA appears to be safe and well tolerated even in patients with cardiovascular comorbidities or with increased risk factors for cardiovascular diseases.

  14. PROTAC-induced BET protein degradation as a therapy for castration-resistant prostate cancer

    PubMed Central

    Raina, Kanak; Lu, Jing; Qian, Yimin; Altieri, Martha; Gordon, Deborah; Rossi, Ann Marie K.; Wang, Jing; Chen, Xin; Dong, Hanqing; Siu, Kam; Winkler, James D.; Crew, Andrew P.; Crews, Craig M.; Coleman, Kevin G.

    2016-01-01

    Prostate cancer has the second highest incidence among cancers in men worldwide and is the second leading cause of cancer deaths of men in the United States. Although androgen deprivation can initially lead to remission, the disease often progresses to castration-resistant prostate cancer (CRPC), which is still reliant on androgen receptor (AR) signaling and is associated with a poor prognosis. Some success against CRPC has been achieved by drugs that target AR signaling, but secondary resistance invariably emerges, and new therapies are urgently needed. Recently, inhibitors of bromodomain and extra-terminal (BET) family proteins have shown growth-inhibitory activity in preclinical models of CRPC. Here, we demonstrate that ARV-771, a small-molecule pan-BET degrader based on proteolysis-targeting chimera (PROTAC) technology, demonstrates dramatically improved efficacy in cellular models of CRPC as compared with BET inhibition. Unlike BET inhibitors, ARV-771 results in suppression of both AR signaling and AR levels and leads to tumor regression in a CRPC mouse xenograft model. This study is, to our knowledge, the first to demonstrate efficacy with a small-molecule BET degrader in a solid-tumor malignancy and potentially represents an important therapeutic advance in the treatment of CRPC. PMID:27274052

  15. Lyn tyrosine kinase regulates androgen receptor expression and activity in castrate-resistant prostate cancer

    PubMed Central

    Zardan, A; Nip, K M; Thaper, D; Toren, P; Vahid, S; Beraldi, E; Fazli, L; Lamoureux, F; Gust, K M; Cox, M E; Bishop, J L; Zoubeidi, A

    2014-01-01

    Castrate-resistant prostate cancer (CRPC) progression is a complex process by which prostate cells acquire the ability to survive and proliferate in the absence or under very low levels of androgens. Most CRPC tumors continue to express the androgen receptor (AR) as well as androgen-responsive genes owing to reactivation of AR. Protein tyrosine kinases have been implicated in supporting AR activation under castrate conditions. Here we report that Lyn tyrosine kinase expression is upregulated in CRPC human specimens compared with hormone naive or normal tissue. Lyn overexpression enhanced AR transcriptional activity both in vitro and in vivo and accelerated CRPC. Reciprocally, specific targeting of Lyn resulted in a decrease of AR transcriptional activity in vitro and in vivo and prolonged time to castration. Mechanistically, we found that targeting Lyn kinase induces AR dissociation from the molecular chaperone Hsp90, leading to its ubiquitination and proteasomal degradation. This work indicates a novel mechanism of regulation of AR stability and transcriptional activity by Lyn and justifies further investigation of the Lyn tyrosine kinase as a therapeutic target for the treatment of CRPC. PMID:25133482

  16. A Study of Combination Bicalutamide and Raloxifene for Patients With Castration-Resistant Prostate Cancer.

    PubMed

    Ho, Thai H; Nunez-Nateras, Rafael; Hou, Yue-Xian; Bryce, Alan H; Northfelt, Donald W; Dueck, Amylou C; Wong, Bryan; Stanton, Melissa L; Joseph, Richard W; Castle, Erik P

    2017-04-01

    Prostate tissue expresses 2 estrogen receptor (ER) isoforms, ER-α and ER-β, and estrogen-based therapies have shown activity in preclinical studies. Raloxifene, a selective ER modulator, has inhibited the growth of prostate cancer xenograft models and was tested in a phase II trial of castration-resistant prostate cancer (CRPC), with some patients achieving stable disease. However, no studies have examined the safety of the combination of bicalutamide plus raloxifene for CRPC. Therefore, we investigated the safety of treatment with bicalutamide plus raloxifene in patients with CRPC in an initial study. We conducted a study to evaluate the toxicity (primary endpoint) of the combination of bicalutamide (50 mg) and raloxifene (60 mg) in 28-day cycles (maximum, 6 cycles) in men with progressive CRPC. The secondary endpoint, quality of life (QOL), was assessed by patients using a 6-item linear analog self-assessment or hormonal domain scale of the Expanded Prostate Cancer Index Composite. We enrolled 18 patients with CRPC in the study to evaluate the safety of, and patient assessment of QOL (mental, physical, social, emotional, and spiritual) with, bicalutamide plus raloxifene therapy. No grade 3 or 4 adverse events occurred. None of the 18 patients required dose reductions. The patient assessment of QOL showed no statistically significant changes after 2 treatment cycles. The median progression-free survival with bicalutamide plus raloxifene was 1.9 months (95% confidence interval, 1.8-2.8 months). The results of the present study have shown that bicalutamide/raloxifene treatment is well tolerated. However, limited clinical activity occurred in men with CRPC who had previously undergone secondary hormonal therapy or chemotherapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Epithelial Plasticity in Castration-Resistant Prostate Cancer: Biology of the Lethal Phenotype

    DTIC Science & Technology

    2014-07-01

    included either abiraterone (n=8), enzalutamide (n=7), nilutamide (n=6), or ketoconazole (n=2). The remainder of the men received protocol-directed...Prior therapies ADT or orchiectomy Bicalutamide, nilutamide, or flutamide, n (%) Ketoconazole , n (%) Abiraterone, enzalutamide, or TAK700, n...Efficacy of docetaxel-based chemotherapy following ketoconazole in metastatic castration-resistant prostate cancer. Urol Oncol 2012 (epub ahead of print

  18. Dutch Economic Value of Radium-223 in Metastatic Castration-Resistant Prostate Cancer.

    PubMed

    Peters, Michel L; de Meijer, Claudine; Wyndaele, Dirk; Noordzij, Walter; Leliveld-Kors, Annemarie M; van den Bosch, Joan; van den Berg, Pieter H; Baka, Agni; Gaultney, Jennifer G

    2017-09-02

    The treatment of metastatic castration-resistant prostate cancer has changed with the introduction of radium-223, cabazitaxel, abiraterone and enzalutamide. To assess value for money, their cost effectiveness in patients with metastatic castration-resistant prostate cancer previously treated with docetaxel from the Dutch societal perspective was investigated. A cost-effectiveness analysis was conducted using efficacy, symptomatic skeletal-related event and safety data obtained from indirect treatment comparisons. Missing skeletal-related event data for cabazitaxel were conservatively assumed to be identical to radium-223. A Markov model combined these clinical inputs with Dutch-specific resource use and costs for metastatic castration-resistant prostate cancer treatment from a societal perspective. Total quality-adjusted life-years and costs in 2017 euros were calculated over a 5-year (lifetime) time horizon. Radium-223 resulted in €6092 and €4465 lower costs and 0.02 and 0.01 higher quality-adjusted life-years compared with abiraterone and cabazitaxel, respectively, demonstrating dominance of radium-223. Sensitivity analyses reveal a 64% (54%) chance of radium-223 being cost effective compared with abiraterone (cabazitaxel) at the informal €80,000 willingness-to-pay threshold. Compared with enzalutamide, radium-223 resulted in slightly lower quality-adjusted life-years (-0.06) and €7390 lower costs, revealing a 61% chance of radium-223 being cost effective compared with enzalutamide. The lower costs of radium-223 compared with abiraterone and enzalutamide are driven by lower drug costs and prevention of expensive skeletal-related events. Compared with cabazitaxel, the lower costs of radium-223 are driven by lower costs of the drug, administration and adverse events. Radium-223 may be a less costly treatment strategy offering similar gains in health benefits compared with abiraterone, cabazitaxel and enzalutamide in patients with metastatic castration-resistant

  19. Castration-Resistant Prostate Cancer Bone Metastasis Response Measured by 18F-Fluoride PET After Treatment with Dasatinib and Correlation with Progression-Free Survival: Results from American College of Radiology Imaging Network 6687

    PubMed Central

    Yu, Evan Y.; Duan, Fenghai; Muzi, Mark; Deng, Xuan; Chin, Bennett B.; Alumkal, Joshi J.; Taplin, Mary-Ellen; Taub, Jina M.; Herman, Ben; Higano, Celestia S.; Doot, Robert K.; Hartfeil, Donna; Febbo, Philip G.; Mankoff, David A.

    2015-01-01

    18F-fluoride PET quantitatively images bone metabolism and may serve as a pharmacodynamic assessment for systemic therapy such as dasatinib, a potent SRC kinase inhibitor, with activity in bone. Methods This was an imaging companion trial (American College of Radiology Imaging Network [ACRIN] 6687) to a multicenter metastatic castration-resistant prostate cancer (CRPC) tissue biomarker–guided therapeutic trial (NCT00918385). Men with bone metastatic CRPC underwent 18F-fluoride PET before and 12 weeks after initiation of dasatinib (100 mg daily). Dynamic imaging was performed over a 15-cm field of view for trial assessments. The primary endpoint was to determine whether changes in 18F-fluoride incorporation in tumor and normal bone occurred in response to dasatinib. Other endpoints included differential effect of dasatinib between 18F-fluoride incorporation in tumor and normal bone, 18F-fluoride transport in bone metastases, correlation with progression-free survival (PFS), prostate-specific antigen, and markers of bone turnover. Results Eighteen participants enrolled, and 17 underwent interpretable baseline 18F-fluoride PET imaging before initiation of dasatinib. Twelve of 17 patients underwent on-treatment PET imaging. Statistically significant changes in response to dasatinib were identified by the SUVmaxavg (average of maximum standardized uptake value [SUVmax] for up to 5 tumors within the dynamic field of view) in bone metastases (P = 0.0002), with a significant differential 18F-fluoride PET response between tumor and normal bone (P < 0.0001). Changes in 18F-fluoride incorporation in bone metastases had borderline correlation with PFS by SUVmaxavg (hazard ratio, 0.91; 95% confidence interval, 0.82–1.00; P = 0.056). Changes by SUVmaxavg correlated with bone alkaline phosphatase (P = 0.0014) but not prostate-specific antigen (P = 0.47). Conclusion: This trial provides evidence of the ability 18F-fluoride PET to delineate treatment response of dasatinib in

  20. Castration-resistant prostate cancer bone metastasis response measured by 18F-fluoride PET after treatment with dasatinib and correlation with progression-free survival: results from American College of Radiology Imaging Network 6687.

    PubMed

    Yu, Evan Y; Duan, Fenghai; Muzi, Mark; Deng, Xuan; Chin, Bennett B; Alumkal, Joshi J; Taplin, Mary-Ellen; Taub, Jina M; Herman, Ben; Higano, Celestia S; Doot, Robert K; Hartfeil, Donna; Febbo, Philip G; Mankoff, David A

    2015-03-01

    (18)F-fluoride PET quantitatively images bone metabolism and may serve as a pharmacodynamic assessment for systemic therapy such as dasatinib, a potent SRC kinase inhibitor, with activity in bone. This was an imaging companion trial (American College of Radiology Imaging Network [ACRIN] 6687) to a multicenter metastatic castration-resistant prostate cancer (CRPC) tissue biomarker-guided therapeutic trial (NCT00918385). Men with bone metastatic CRPC underwent (18)F-fluoride PET before and 12 weeks after initiation of dasatinib (100 mg daily). Dynamic imaging was performed over a 15-cm field of view for trial assessments. The primary endpoint was to determine whether changes in (18)F-fluoride incorporation in tumor and normal bone occurred in response to dasatinib. Other endpoints included differential effect of dasatinib between (18)F-fluoride incorporation in tumor and normal bone, (18)F-fluoride transport in bone metastases, correlation with progression-free survival (PFS), prostate-specific antigen, and markers of bone turnover. Eighteen participants enrolled, and 17 underwent interpretable baseline (18)F-fluoride PET imaging before initiation of dasatinib. Twelve of 17 patients underwent on-treatment PET imaging. Statistically significant changes in response to dasatinib were identified by the SUVmaxavg (average of maximum standardized uptake value [SUVmax] for up to 5 tumors within the dynamic field of view) in bone metastases (P = 0.0002), with a significant differential (18)F-fluoride PET response between tumor and normal bone (P < 0.0001). Changes in (18)F-fluoride incorporation in bone metastases had borderline correlation with PFS by SUVmaxavg (hazard ratio, 0.91; 95% confidence interval, 0.82-1.00; P = 0.056). Changes by SUVmaxavg correlated with bone alkaline phosphatase (P = 0.0014) but not prostate-specific antigen (P = 0.47). This trial provides evidence of the ability (18)F-fluoride PET to delineate treatment response of dasatinib in CRPC bone

  1. Targeting Taxanes to Castration-Resistant Prostate Cancer Cells by Nanobubbles and Extracorporeal Shock Waves.

    PubMed

    Marano, Francesca; Rinella, Letizia; Argenziano, Monica; Cavalli, Roberta; Sassi, Francesca; D'Amelio, Patrizia; Battaglia, Antonino; Gontero, Paolo; Bosco, Ornella; Peluso, Rossella; Fortunati, Nicoletta; Frairia, Roberto; Catalano, Maria Graziella

    2016-01-01

    To target taxanes to castration-resistant prostate cancer cells, glycol-chitosan nanobubbles loaded with paclitaxel and docetaxel were constructed. The loaded nanobubbles were then combined with Extracorporeal Shock Waves, acoustic waves widely used in urology and orthopedics, with no side effects. Nanobubbles, with an average diameter of 353.3 ± 15.5 nm, entered two different castration-resistant prostate cancer cells (PC3 and DU145) as demonstrated by flow cytometry and immunofluorescence. The shock waves applied increased the amount of intracellular nanobubbles. Loading nanobubbles with paclitaxel and docetaxel and combining them with shock waves generated the highest cytotoxic effects, resulting in a paclitaxel GI50 reduction of about 55% and in a docetaxel GI50 reduction of about 45% respectively. Combined treatment also affected cell migration. Paclitaxel-loaded nanobubbles and shock waves reduced cell migration by more than 85% with respect to paclitaxel alone; whereas docetaxel-loaded nanobubbles and shock waves reduced cell migration by more than 82% with respect to docetaxel alone. The present data suggest that nanobubbles can act as a stable taxane reservoir in castration-resistant prostate cancer cells and shock waves can further increase drug release from nanobubbles leading to higher cytotoxic and anti-migration effect.

  2. Crosstalk between RON and androgen receptor signaling in the development of castration resistant prostate cancer

    PubMed Central

    Batth, Izhar; Yun, Huiyoung; Hussain, Suleman; Meng, Peng; Osumulski, Powel; Huang, Tim Hui-Ming; Bedolla, Roble; Profit, Amanda; Reddick, Robert; Kumar, Addanki

    2016-01-01

    Castrate-resistant prostate cancer (CRPC) is the fatal form of prostate cancer. Although reactivation of androgen receptor (AR) occurs following androgen deprivation, the precise mechanism involved is unclear. Here we show that the receptor tyrosine kinase, RON alters mechanical properties of cells to influence epithelial to mesenchymal transition and functions as a transcription factor to differentially regulate AR signaling. RON inhibits AR activation and subset of AR-regulated transcripts in androgen responsive LNCaP cells. However in C4-2B, a castrate-resistant sub-line of LNCaP and AR-negative androgen independent DU145 cells, RON activates subset of AR-regulated transcripts. Expression of AR in PC-3 cells leads to activation of RON under androgen deprivation but not under androgen proficient conditions implicating a role for RON in androgen independence. Consistently, RON expression is significantly elevated in castrate resistant prostate tumors. Taken together our results suggest that RON activation could aid in promoting androgen independence and that inhibition of RON in combination with AR antagonist(s) merits serious consideration as a therapeutic option during hormone deprivation therapy. PMID:26872377

  3. Crosstalk between RON and androgen receptor signaling in the development of castration resistant prostate cancer.

    PubMed

    Batth, Izhar; Yun, Huiyoung; Hussain, Suleman; Meng, Peng; Osmulski, Pawel; Huang, Tim Hui-Ming; Bedolla, Roble; Profit, Amanda; Reddick, Robert; Kumar, Addanki

    2016-03-22

    Castrate-resistant prostate cancer (CRPC) is the fatal form of prostate cancer. Although reactivation of androgen receptor (AR) occurs following androgen deprivation, the precise mechanism involved is unclear. Here we show that the receptor tyrosine kinase, RON alters mechanical properties of cells to influence epithelial to mesenchymal transition and functions as a transcription factor to differentially regulate AR signaling. RON inhibits AR activation and subset of AR-regulated transcripts in androgen responsive LNCaP cells. However in C4-2B, a castrate-resistant sub-line of LNCaP and AR-negative androgen independent DU145 cells, RON activates subset of AR-regulated transcripts. Expression of AR in PC-3 cells leads to activation of RON under androgen deprivation but not under androgen proficient conditions implicating a role for RON in androgen independence. Consistently, RON expression is significantly elevated in castrate resistant prostate tumors. Taken together our results suggest that RON activation could aid in promoting androgen independence and that inhibition of RON in combination with AR antagonist(s) merits serious consideration as a therapeutic option during hormone deprivation therapy.

  4. Targeting Taxanes to Castration-Resistant Prostate Cancer Cells by Nanobubbles and Extracorporeal Shock Waves

    PubMed Central

    Argenziano, Monica; Cavalli, Roberta; Sassi, Francesca; D’Amelio, Patrizia; Battaglia, Antonino; Gontero, Paolo; Bosco, Ornella; Peluso, Rossella; Fortunati, Nicoletta; Frairia, Roberto; Catalano, Maria Graziella

    2016-01-01

    To target taxanes to castration-resistant prostate cancer cells, glycol-chitosan nanobubbles loaded with paclitaxel and docetaxel were constructed. The loaded nanobubbles were then combined with Extracorporeal Shock Waves, acoustic waves widely used in urology and orthopedics, with no side effects. Nanobubbles, with an average diameter of 353.3 ± 15.5 nm, entered two different castration-resistant prostate cancer cells (PC3 and DU145) as demonstrated by flow cytometry and immunofluorescence. The shock waves applied increased the amount of intracellular nanobubbles. Loading nanobubbles with paclitaxel and docetaxel and combining them with shock waves generated the highest cytotoxic effects, resulting in a paclitaxel GI50 reduction of about 55% and in a docetaxel GI50 reduction of about 45% respectively. Combined treatment also affected cell migration. Paclitaxel-loaded nanobubbles and shock waves reduced cell migration by more than 85% with respect to paclitaxel alone; whereas docetaxel-loaded nanobubbles and shock waves reduced cell migration by more than 82% with respect to docetaxel alone. The present data suggest that nanobubbles can act as a stable taxane reservoir in castration-resistant prostate cancer cells and shock waves can further increase drug release from nanobubbles leading to higher cytotoxic and anti-migration effect. PMID:28002459

  5. Enzalutamide: targeting the androgen signalling pathway in metastatic castration-resistant prostate cancer.

    PubMed

    Schalken, Jack; Fitzpatrick, John M

    2016-02-01

    Significant progress has been made in the understanding of the underlying cancer biology of castration-resistant prostate cancer (CRPC) with the androgen receptor (AR) signalling pathway remaining implicated throughout the prostate cancer disease continuum. Reactivation of the AR signalling pathway is considered to be a key driver of CRPC progression and, as such, the AR is a logical target for therapy in CRPC. The objective of this review was to understand the importance of AR signalling in the treatment of patients with metastatic CRPC (mCRPC) and to discuss the clinical benefits associated with inhibition of the AR signalling pathway. A search was conducted to identify articles relating to the role of AR signalling in CRPC and therapies that inhibit the AR signalling pathway. Current understanding of prostate cancer has identified the AR signalling pathway as a logical target for the treatment of CRPC. Available therapies that inhibit the AR signalling pathway include AR blockers, androgen biosynthesis inhibitors, and AR signalling inhibitors. Enzalutamide, the first approved AR signalling inhibitor, has a novel mode of action targeting AR signalling at three key stages. The direct mode of action of enzalutamide has been shown to translate into clinical responses in patients with mCRPC. In conclusion, the targeting of the AR signalling pathway in patients with mCRPC results in numerous clinical benefits. As the number of treatment options increase, more trials evaluating the sequencing and combination of treatments are required. This review highlights the continued importance of targeting a key driver in the progression of CRPC, AR signalling, and the clinical benefits associated with inhibition of the AR signalling pathway in the treatment of patients with CRPC.

  6. Abiraterone in the treatment of metastatic castration-resistant prostate cancer.

    PubMed

    Mostaghel, Elahe A

    2014-01-01

    Androgen deprivation therapy remains the single most effective treatment for the initial therapy of advanced prostate cancer, but is uniformly marked by progression to castration-resistant prostate cancer (CRPC). Residual tumor androgens and androgen axis activation are now recognized to play a prominent role in mediating CRPC progression. Despite suppression of circulating testosterone to castrate levels, castration does not eliminate androgens from the prostate tumor microenvironment and residual androgen levels are well within the range capable of activating the androgen receptor (AR) and AR-mediated gene expression. Accordingly, therapeutic strategies that more effectively target production of intratumoral androgens are necessary. The introduction of abiraterone, a potent suppressor of cytochrome P450 17 α-hydroxysteroid dehydrogenase-mediated androgen production, has heralded a new era in the hormonal treatment of men with metastatic CRPC. Herein, the androgen and AR-mediated mechanisms that contribute to CRPC progression and establish cytochrome P450 17 α-hydroxysteroid dehydrogenase as a critical therapeutic target are briefly reviewed. The mechanism of action and pharmacokinetics of abiraterone are reviewed and its recently described activity against AR and 3-β-hydroxysteroid dehydrogenase is discussed. The Phase I and II data initially demonstrating the efficacy of abiraterone and Phase III data supporting its approval for patients with metastatic CRPC are reviewed. The safety and tolerability of abiraterone, including the incidence and management of side effects and potential drug interactions, are discussed. The current place of abiraterone in CRPC therapy is reviewed and early evidence regarding cross-resistance of abiraterone with taxane therapy, mechanisms of resistance to abiraterone, and observations of an abiraterone withdrawal response are presented. Future directions in the use of abiraterone, including optimal dosing strategies, the role of

  7. Estradiol suppresses tissue androgens and prostate cancer growth in castration resistant prostate cancer

    PubMed Central

    2010-01-01

    Background Estrogens suppress tumor growth in prostate cancer which progresses despite anorchid serum androgen levels, termed castration resistant prostate cancers (CRPC), although the mechanisms are unclear. We hypothesize that estrogen inhibits CRPC in anorchid animals by suppressing tumoral androgens, an effect independent of the estrogen receptor. Methods The human CRPC xenograft LuCaP 35V was implanted into orchiectomized male SCID mice and established tumors were treated with placebo, 17β-estradiol or 17β-estradiol and estrogen receptor antagonist ICI 182,780. Effects of 17β-estradiol on tumor growth were evaluated and tissue testosterone (T) and dihydrotestosterone (DHT) evaluated by mass spectrometry. Results Treatment of LuCaP 35V with 17β-estradiol slowed tumor growth compared to controls (tumor volume at day 21: 785 ± 81 mm3 vs. 1195 ± 84 mm3, p = 0.002). Survival was also significantly improved in animals treated with 17β-estradiol (p = 0.03). The addition of the estrogen receptor antagonist ICI 182,780 did not significantly change survival or growth. 17β-estradiol in the presence and absence of ICI 182,780 suppressed tumor testosterone (T) and dihydrotestosterone (DHT) as assayed by mass spectrometry. Tissue androgens in placebo treated LuCaP 35V xenografts were; T = 0.71 ± 0.28 pg/mg and DHT = 1.73 ± 0.36 pg/mg. In 17β-estradiol treated LuCaP35V xenografts the tissue androgens were, T = 0.20 ± 0.10 pg/mg and DHT = 0.15 ± 0.15 pg/mg, (p < 0.001 vs. controls). Levels of T and DHT in control liver tissue were < 0.2 pg/mg. Conclusions CRPC in anorchid animals maintains tumoral androgen levels despite castration. 17β-estradiol significantly suppressed tumor T and DHT and inhibits growth of CRPC in an estrogen receptor independent manner. The ability to manipulate tumoral androgens will be critical in the development and testing of agents targeting CRPC through tissue steroidogenesis. PMID:20509933

  8. Targeting androgen receptor versus targeting androgens to suppress castration resistant prostate cancer.

    PubMed

    Guo, Changcheng; Yeh, Shuyuan; Niu, Yuanjie; Li, Gonghui; Zheng, Junhua; Li, Lei; Chang, Chawnshang

    2017-07-01

    Prostate cancer (PCa) is the 2nd leading cause of cancer-related death among men in the United States and its progression is tightly associated with the androgen/androgen receptor (AR) signals. Men castrated before puberty (eunuchs) or men with inherited deficiency of type II 5α-reductase (with failure to convert testosterone to the more potent dihydrotestosterone) (DHT) do not develop PCa. To date, androgen deprivation therapy (ADT) with anti-androgen treatments to reduce or prevent androgens from binding to the AR remains the main therapeutic option for advanced PCa since its discovery by Huggins and Hodges in 1941. Multiple strategies related to surgical/chemical castration with combinations of various anti-androgens, including Cyproterone Acetate, Flutamide, Nilutamide, Bicalutamide (Casodex) and Enzalutamide, as well as some androgen synthesis blockers, including Abiraterone, have been used to control PCa progression. However, patients on ADT with anti-androgen treatment eventually develop resistance, which might be accompanied with the unwanted side effects of enhanced metastasis. New therapeutic approaches via directly targeting the AR with ASC-J9(®), Cisplatin, EPI-001, Niclosamide, and VPC compounds as well as silencing AR with siRNAs or non-coding RNAs have been developed to further suppress PCa at the castration resistant stages. Published by Elsevier B.V.

  9. Acquired resistance to the second-generation androgen receptor antagonist enzalutamide in castration-resistant prostate cancer.

    PubMed

    Kregel, Steven; Chen, James L; Tom, Westin; Krishnan, Venkatesh; Kach, Jacob; Brechka, Hannah; Fessenden, Tim B; Isikbay, Masis; Paner, Gladell P; Szmulewitz, Russell Z; Vander Griend, Donald J

    2016-05-03

    Enzalutamide (MDV3100) is a second generation Androgen Receptor (AR) antagonist with proven efficacy in the treatment of castration resistant prostate cancer (CRPC). The majority of treated patients, however, develop resistance and disease progression and there is a critical need to identify novel targetable pathways mediating resistance. The purpose of this study was to develop and extensively characterize a series of enzalutamide-resistant prostate cancer cell lines. Four genetically distinct AR-positive and AR-pathway dependent prostate cancer cell lines (CWR-R1, LAPC-4, LNCaP, VCaP) were made resistant to enzalutamide by long-term culture (> 6 months) in enzalutamide. Extensive characterization of these lines documented divergent in vitro growth characteristics and AR pathway modulation. Enzalutamide-resistant LNCaP and CWR-R1 cells, but not LAPC-4 and VCAP cells, demonstrated increased castration-resistant and metastatic growth in vivo. Global gene expression analyses between short-term enzalutamide treated vs. enzalutamide-resistant cells identified both AR pathway and non-AR pathway associated changes that were restored upon acquisition of enzalutamide resistance. Further analyses revealed very few common gene expression changes between the four resistant cell lines. Thus, while AR-mediated pathways contribute in part to enzalutamide resistance, an unbiased approach across several cell lines demonstrates a greater contribution toward resistance via pleiotropic, non-AR mediated mechanisms.

  10. Acquired resistance to the second-generation androgen receptor antagonist enzalutamide in castration-resistant prostate cancer

    PubMed Central

    Kregel, Steven; Chen, James L.; Tom, Westin; Krishnan, Venkatesh; Kach, Jacob; Brechka, Hannah; Fessenden, Tim B.; Isikbay, Masis; Paner, Gladell P.

    2016-01-01

    Enzalutamide (MDV3100) is a second generation Androgen Receptor (AR) antagonist with proven efficacy in the treatment of castration resistant prostate cancer (CRPC). The majority of treated patients, however, develop resistance and disease progression and there is a critical need to identify novel targetable pathways mediating resistance. The purpose of this study was to develop and extensively characterize a series of enzalutamide-resistant prostate cancer cell lines. Four genetically distinct AR-positive and AR-pathway dependent prostate cancer cell lines (CWR-R1, LAPC-4, LNCaP, VCaP) were made resistant to enzalutamide by long-term culture (> 6 months) in enzalutamide. Extensive characterization of these lines documented divergent in vitro growth characteristics and AR pathway modulation. Enzalutamide-resistant LNCaP and CWR-R1 cells, but not LAPC-4 and VCAP cells, demonstrated increased castration-resistant and metastatic growth in vivo. Global gene expression analyses between short-term enzalutamide treated vs. enzalutamide-resistant cells identified both AR pathway and non-AR pathway associated changes that were restored upon acquisition of enzalutamide resistance. Further analyses revealed very few common gene expression changes between the four resistant cell lines. Thus, while AR-mediated pathways contribute in part to enzalutamide resistance, an unbiased approach across several cell lines demonstrates a greater contribution toward resistance via pleiotropic, non-AR mediated mechanisms. PMID:27036029

  11. Mitosis Phase Enrichment with Identification of Mitotic Centromere-Associated Kinesin As a Therapeutic Target in Castration-Resistant Prostate Cancer

    PubMed Central

    Sircar, Kanishka; Huang, Heng; Hu, Limei; Liu, Yuexin; Dhillon, Jasreman; Cogdell, David; Aprikian, Armen; Efstathiou, Eleni; Navone, Nora; Troncoso, Patricia; Zhang, Wei

    2012-01-01

    The recently described transcriptomic switch to a mitosis program in castration-resistant prostate cancer (CRPC) suggests that mitotic proteins may be rationally targeted at this lethal stage of the disease. In this study, we showed upregulation of the mitosis-phase at the protein level in our cohort of 51 clinical CRPC cases and found centrosomal aberrations to also occur preferentially in CRPC compared with untreated, high Gleason–grade hormone-sensitive prostate cancer (P<0.0001). Expression profiling of chemotherapy-resistant CRPC samples (n = 25) was performed, and the results were compared with data from primary chemotherapy-naïve CRPC (n = 10) and hormone-sensitive prostate cancer cases (n = 108). Our results showed enrichment of mitosis-phase genes and pathways, with progression to both castration-resistant and chemotherapy-resistant disease. The mitotic centromere-associated kinesin (MCAK) was identified as a novel mitosis-phase target in prostate cancer that was overexpressed in multiple CRPC gene-expression datasets. We found concordant gene expression of MCAK between our parent and murine CRPC xenograft pairs and increased MCAK protein expression with clinical progression of prostate cancer to a castration-resistant disease stage. Knockdown of MCAK arrested the growth of prostate cancer cells suggesting its utility as a potential therapeutic target. PMID:22363599

  12. Novel Imidazopyridine Derivatives Possess Anti-Tumor Effect on Human Castration-Resistant Prostate Cancer Cells

    PubMed Central

    Muniyan, Sakthivel; D’Cunha, Napoleon; Robinson, Tashika; Hoelting, Kyle; Dwyer, Jennifer G.; Bu, Xiu R.; Batra, Surinder K.; Lin, Ming-Fong

    2015-01-01

    Prostate cancer (PCa) is the second leading cause of cancer-related death afflicting United States males. Most treatments to-date for metastatic PCa include androgen-deprivation therapy and second-generation anti-androgens such as abiraterone acetate and enzalutamide. However, a majority of patients eventually develop resistance to these therapies and relapse into the lethal, castration-resistant form of PCa to which no adequate treatment option remains. Hence, there is an immediate need to develop effective therapeutic agents toward this patient population. Imidazopyridines have recently been shown to possess Akt kinase inhibitory activity; thus in this study, we investigated the inhibitory effect of novel imidazopyridine derivatives HIMP, M-MeI, OMP, and EtOP on different human castration-resistant PCa cells. Among these compounds, HIMP and M-MeI were found to possess selective dose- and time-dependent growth inhibition: they reduced castration-resistant PCa cell proliferation and spared benign prostate epithelial cells. Using LNCaP C-81 cells as the model system, these compounds also reduced colony formation as well as cell adhesion and migration, and M-MeI was the most potent in all studies. Further investigation revealed that while HIMP primarily inhibits PCa cell growth via suppression of PI3K/Akt signaling pathway, M-MeI can inhibit both PI3K/Akt and androgen receptor pathways and arrest cell growth in the G2 phase. Thus, our results indicate the novel compound M-MeI to be a promising candidate for castration-resistant PCa therapy, and future studies investigating the mechanism of imidazopyridine inhibition may aid to the development of effective anti-PCa agents. PMID:26121643

  13. Novel Imidazopyridine Derivatives Possess Anti-Tumor Effect on Human Castration-Resistant Prostate Cancer Cells.

    PubMed

    Ingersoll, Matthew A; Lyons, Anastesia S; Muniyan, Sakthivel; D'Cunha, Napoleon; Robinson, Tashika; Hoelting, Kyle; Dwyer, Jennifer G; Bu, Xiu R; Batra, Surinder K; Lin, Ming-Fong

    2015-01-01

    Prostate cancer (PCa) is the second leading cause of cancer-related death afflicting United States males. Most treatments to-date for metastatic PCa include androgen-deprivation therapy and second-generation anti-androgens such as abiraterone acetate and enzalutamide. However, a majority of patients eventually develop resistance to these therapies and relapse into the lethal, castration-resistant form of PCa to which no adequate treatment option remains. Hence, there is an immediate need to develop effective therapeutic agents toward this patient population. Imidazopyridines have recently been shown to possess Akt kinase inhibitory activity; thus in this study, we investigated the inhibitory effect of novel imidazopyridine derivatives HIMP, M-MeI, OMP, and EtOP on different human castration-resistant PCa cells. Among these compounds, HIMP and M-MeI were found to possess selective dose- and time-dependent growth inhibition: they reduced castration-resistant PCa cell proliferation and spared benign prostate epithelial cells. Using LNCaP C-81 cells as the model system, these compounds also reduced colony formation as well as cell adhesion and migration, and M-MeI was the most potent in all studies. Further investigation revealed that while HIMP primarily inhibits PCa cell growth via suppression of PI3K/Akt signaling pathway, M-MeI can inhibit both PI3K/Akt and androgen receptor pathways and arrest cell growth in the G2 phase. Thus, our results indicate the novel compound M-MeI to be a promising candidate for castration-resistant PCa therapy, and future studies investigating the mechanism of imidazopyridine inhibition may aid to the development of effective anti-PCa agents.

  14. Niclosamide inhibits androgen receptor variants expression and overcomes enzalutamide resistance in castration resistant prostate cancer

    PubMed Central

    Zhu, Yezi; Nadiminty, Nagalakshmi; Schwartz, Chad T.; Evans, Christopher P.; Gao, Allen C.

    2014-01-01

    Purpose Enzalutamide, a second-generation antiandrogen, was recently approved for the treatment of castration-resistant prostate cancer (CRPC) in patients who no longer respond to docetaxel. Despite these advances that provide temporary respite, resistance to enzalutamide occurs frequently. AR splice variants such as AR-V7 have recently been shown to drive castration resistant growth and resistance to enzalutamide. This study was designed to identify inhibitors of AR variants and test its ability to overcome resistance to enzalutamide. Experimental Design The drug screening was conducted using luciferase activity assay to determine the activity of AR-V7 after treatment with the compounds in the Prestwick Chemical Library, which contains about 1120 FDA-approved drugs. The effects of the identified inhibitors on AR-V7 activity and enzalutamide sensitivity were characterized in CRPC and enzalutamide-resistant prostate cancer cells in vitro and in vivo. Results Niclosamide, an FDA-approved anti-helminthic drug, was identified as a potent AR-V7 inhibitor in prostate cancer cells. Niclosamide significantly downregulated AR-V7 protein expression by protein degradation through a proteasome dependent pathway. Niclosamide also inhibited AR-V7 transcription activity and reduced the recruitment of AR-V7 to the PSA promoter. Niclosamide inhibited prostate cancer cell growth in vitro and tumor growth in vivo. Furthermore, the combination of niclosamide and enzalutamide resulted in significantly inhibition of enzalutamide-resistant tumor growth, suggesting that Niclosamide enhances enzalutamide therapy and overcomes enzalutamide resistance in castration resistant prostate cancer cells. Conclusions Niclosamide was identified as a novel inhibitor of AR variants. Our findings offer preclinical validation of niclosamide as a promising inhibitor of androgen receptor variants to treat, either alone or in combination with current antiandrogen therapies, advanced prostate cancer patients

  15. Sequencing new agents after docetaxel in patients with metastatic castration-resistant prostate cancer.

    PubMed

    Maines, Francesca; Caffo, Orazio; Veccia, Antonello; Trentin, Chiara; Tortora, Giampaolo; Galligioni, Enzo; Bria, Emilio

    2015-12-01

    Two new hormonal agents (NHAs), abiraterone and enzalutamide, and one chemotherapeutic agent, cabazitaxel (CABA) improved overall survival (OS) in patients with metastatic castration-resistant prostate cancer (mCRPC) who progress after docetaxel. Although several analyses of patient cohorts receiving a sequence of two different new agents (NAs) after docetaxel have been published, no definite conclusions can be drawn regarding the best treatment strategy. All published studies reporting monthly OS rates of mCRPC patients receiving third-line NA after having previously received docetaxel and another NA have been analyzed. The treatments were merged into three groups: one NHA followed by another, one NHA followed by CABA, and CABA followed by one NHA. The cumulative monthly OS rates in each group were determined using a weighted-average approach. Thirteen retrospective studies including 1016 patients who received NHA/NHA (469), NHA/CABA (318) or CABA/NHA (229) were evaluated. The 12-month OS rates were 28.5%, 61.3%, and 76.4%, respectively. There were no statistically significant differences in terms of known prognostic factors. Although the retrospective nature of the studies and potential selection biases, our data seem to confirm the potential cumulative survival benefit of using the NAs sequentially after docetaxel. There was no clear superiority of any one of the three strategies, but a sequence that includes CABA seems to suggest a possible OS advantage. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  16. FOXA1 regulates androgen receptor variant activity in models of castrate-resistant prostate cancer

    PubMed Central

    Nakjang, Sirintra; Chaytor, Lewis; Grey, James; Robson, Craig N.; Gaughan, Luke

    2015-01-01

    Retention of androgen receptor (AR) signalling in castrate-resistant prostate cancer (CRPC) highlights the requirement for the development of more effective AR targeting therapies. A key mechanism of resistance to anti-androgens is through expression of constitutively active AR variants (AR-Vs) that are refractory to next-generation therapies, including Enzalutamide and Abiraterone. By maintaining an androgenic gene signature, AR-Vs drive tumour survival and progression in castrate conditions. Critically, however, our understanding of the mechanics of AR-V-driven transcription is limited, particularly with respect to dependency on pioneer factor function. Here we show that depletion of FOXA1 in the CWR22Rv1 CRPC cell line abrogates the oncogenic potential of AR-Vs. Gene expression profiling reveals that approximately 41% of the AR-V transcriptome requires FOXA1 and that depletion of FOXA1 attenuates AR-V binding at a sub-set of analysed co-regulated genes. Interestingly, AR-V levels are elevated in cells depleted of FOXA1 as a consequence of attenuated negative feedback on the AR gene, but is insufficient to maintain cell growth as evidenced by marked anti-proliferative effects in FOXA1 knockdown cells. In all, our data suggests that AR-Vs are dependent on FOXA1 for sustaining a pro-proliferative gene signature and agents targeting FOXA1 may represent novel therapeutic options for CRPC patients. PMID:26336819

  17. FOXA1 regulates androgen receptor variant activity in models of castrate-resistant prostate cancer.

    PubMed

    Jones, Dominic; Wade, Mark; Nakjang, Sirintra; Chaytor, Lewis; Grey, James; Robson, Craig N; Gaughan, Luke

    2015-10-06

    Retention of androgen receptor (AR) signalling in castrate-resistant prostate cancer (CRPC) highlights the requirement for the development of more effective AR targeting therapies. A key mechanism of resistance to anti-androgens is through expression of constitutively active AR variants (AR-Vs) that are refractory to next-generation therapies, including Enzalutamide and Abiraterone. By maintaining an androgenic gene signature, AR-Vs drive tumour survival and progression in castrate conditions. Critically, however, our understanding of the mechanics of AR-V-driven transcription is limited, particularly with respect to dependency on pioneer factor function. Here we show that depletion of FOXA1 in the CWR22Rv1 CRPC cell line abrogates the oncogenic potential of AR-Vs. Gene expression profiling reveals that approximately 41% of the AR-V transcriptome requires FOXA1 and that depletion of FOXA1 attenuates AR-V binding at a sub-set of analysed co-regulated genes. Interestingly, AR-V levels are elevated in cells depleted of FOXA1 as a consequence of attenuated negative feedback on the AR gene, but is insufficient to maintain cell growth as evidenced by marked anti-proliferative effects in FOXA1 knockdown cells. In all, our data suggests that AR-Vs are dependent on FOXA1 for sustaining a pro-proliferative gene signature and agents targeting FOXA1 may represent novel therapeutic options for CRPC patients.

  18. Metabolic syndrome in castration-resistant prostate cancer patients treated with abiraterone.

    PubMed

    Conteduca, Vincenza; Caffo, Orazio; Derosa, Lisa; Veccia, Antonello; Petracci, Elisabetta; Chiuri, Vincenzo Emanuele; Santoni, Matteo; Santini, Daniele; Fratino, Lucia; Maines, Francesca; Testoni, Sara; De Giorgi, Ugo

    2015-09-01

    Metabolic syndrome (MS) has not yet been studied in castration-resistant prostate cancer (CRPC) men treated with novel hormonal therapies. The study aims to assess the impact of MS on outcome from time starting abiraterone. We retrospectively evaluated a consecutive series of metastatic CRPC patients treated with abiraterone after docetaxel failure. MS, as defined by modified Adult Treatment Panel (ATP) III criteria, was assessed at the time of initiation of abiraterone, during treatment and follow-up. Sixty-seven of 178 patients evaluated (37.6%) met MS criteria at baseline, before abiraterone initiation, whereas for 11 (9.9%) without MS before treatment with abiraterone this occurred during treatment. Median PFS was equal to 4.7 months for patients with MS versus 9 months for those without MS. Patients with MS had an increased risk of 71% of progression or death for all causes than patients without MS (HR = 1.7, 95% CI [1.2-2.4], P = 0.03). Median OS was 14.7 months and 22.3 months in patients with and without MS, respectively. After adjusting for covariates, MS resulted not significantly associated to OS (HR = 1.42, 95% CI [0.91-2.22], P = 0.073). The presence of MS is a significant risk factor for shorter PFS in CRPC patients treated with abiraterone, even if it does not show a significant impact on OS. A prospective evaluation is warranted. © 2015 Wiley Periodicals, Inc.

  19. The Steroid Receptor Coactivator-3 Is Required for the Development of Castration-resistant Prostate Cancer

    PubMed Central

    Tien, Jean Ching-Yi; Liu, Zhaoliang; Liao, Lan; Wang, Fen; Xu, Yixiang; Wu, Ye-Lin; Zhou, Niya; Ittmann, Michael; Xu, Jianming

    2013-01-01

    The transcriptional coactivator SRC-3 plays a key role to enhance prostate cancer (CaP) cell proliferation. Although SRC-3 is highly expressed in advanced CaP, its role in castration resistant CaP (CRPC) driven by PTEN mutation is unknown. We documented elevated SRC-3 in human CRPC and in PTEN-negative human CaP. Patients with high SRC-3 and undetectable PTEN exhibited decreased recurrence-free survival. To explore the causal relationship in these observations, we generated mice in which both Pten and SRC-3 were inactivated in prostate epithelial cells (Pten3CKO mice), comparing them to mice in which only Pten was inactivated in these cells (PtenCKO mice). SRC-3 deletion impaired cellular proliferation and reduced tumor size. Notably, while castration of PtenCKO control mice increased the aggressiveness of prostate tumors relative to non-castrated counterparts, deletion of SRC-3 in Pten3CKO mice reversed all these changes. In support of this finding, castrated Pten3CKO mice also exhibited decreased levels of phospho-Akt, S6 kinase (RPS6KB1) and phosphorylated S6 protein (RPS6), all of which mediate cell growth and proliferation. Moreover, these tumors appeared to be more differentiated as evidenced by higher levels of Fkbp5, an AR-responsive gene that inhibits Akt signaling. Lastly, these tumors also displayed lower levels of certain androgen-repressed genes such as cyclin E2 and MMP10. Together, our results show that SRC-3 drives CRPC formation and offer preclinical proof of concept for a transcriptional coactivator as a therapeutic target to abrogate CRPC progression. PMID:23650284

  20. Therapy decisions for the symptomatic patient with metastatic castration-resistant prostate cancer

    PubMed Central

    Markowski, Mark C; Pienta, Kenneth J

    2015-01-01

    Metastatic prostate cancer continues to kill approximately 30,000 men per year. Since 2010, five new therapeutic agents have been Food and Drug Administration (FDA) approved to treat metastatic castration-resistant prostate cancer (mCRPC). With the increasing number of therapies available to clinicians, the most effective sequence in which to implement these treatments remains unknown. The presence or absence of symptoms (i.e., bony pain, visceral crisis) is a key parameter that informs the decision-making process regarding therapy. Treatment algorithms based on: 1) asymptomatic/minimal symptoms, 2) moderate symptoms or chemotherapy ineligible or 3) symptomatic disease need to be developed. PMID:25865849

  1. PP2A inhibition as a novel therapeutic target in castration-resistant prostate cancer.

    PubMed

    González-Alonso, Paula; Cristóbal, Ion; Manso, Rebeca; Madoz-Gúrpide, Juan; García-Foncillas, Jesús; Rojo, Federico

    2015-08-01

    Protein phosphatase 2A (PP2A) is a well-known tumor suppressor frequently inhibited in human cancer. Alterations affecting PP2A subunits together with the deregulation of endogenous PP2A inhibitors such as CIP2A and SET have been described as contributing mechanisms to inactivate PP2A in prostate cancer. Moreover, recent findings highlight that functional inactivation of PP2A could represent a key event in the acquisition of castration-resistant phenotype and a novel molecular target with high impact at both clinical and therapeutic levels in prostate cancer.

  2. Andrographolide Targets Androgen Receptor Pathway in Castration-Resistant Prostate Cancer

    PubMed Central

    Liu, Chengfei; Nadiminty, Nagalakshmi; Tummala, Ramakumar; Chun, Jae Yeon; Lou, Wei; Zhu, Yezi; Sun, Meng; Evans, Christopher P.; Zhou, Qinghua; Gao, Allen C.

    2011-01-01

    Androgen receptor (AR) signaling not only plays a pivotal role in the development of androgen-dependent prostate cancer but is also important in the growth and survival of castration-resistant prostate cancer (CRPC). The first line of treatment of androgen-dependent prostate cancer is the use of androgen deprivation therapy. However, most patients will eventually relapse due to development of CRPC. Thus, development of a strategy to target AR for treatment of CRPC is urgently needed. The authors have previously identified andrographolide as an inhibitor of interleukin-6, which can suppress tumor growth of prostate cancer cells by screening compounds from the Prestwick Natural compound library. In this study, they identified that andrographolide can inhibit AR expression and prostate cancer cell growth and induce apoptosis. Andrographolide is able to down-regulate AR expression at both mRNA and protein levels, prevents its nuclear translocation, and inhibits transactivation of its target genes. Andrographolide prevents the binding of Hsp90 to AR, resulting in proteasome-mediated AR degradation. Furthermore, andrographolide inhibits castration-resistant C4-2 cell growth by reducing AR expression and activity. Thus, andrographolide can be developed as a potential therapeutic agent for prostate cancer by inhibition of androgen receptor signaling. PMID:21779488

  3. Biomarkers in the Management and Treatment of Men with Metastatic Castration-Resistant Prostate Cancer

    PubMed Central

    Armstrong, Andrew J.; Eisenberger, Mario A.; Halabi, Susan; Oudard, Stephane; Nanus, David M.; Petrylak, Daniel P.; Sartor, A. Oliver; Scher, Howard I.

    2012-01-01

    Context We have recently witnessed a rapid increase in the number of effective systemic agents for men with metastatic castration-resistant prostate cancer (CRPC), including novel hormonal therapies (abiraterone acetate and MDV3100), immunotherapies (sipu-leucel-T), chemotherapies (cabazitaxel), and bone microenvironment targeting agents (denosumab, radium 223). Given the increasing complexity of treatment decisions for this disease, major research and clinical priorities are (1) finding biomarkers that enable an understanding of the natural history and complex biology of this heterogeneous malignancy, (2) defining predictive biomarkers that identify men most likely to benefit from a given therapy, and (3) identifying biomarkers of early response or progression to optimize outcomes. Objective In this review, we discuss existing and potential biomarkers in CRPC and how they may currently inform prognosis, aid in treatment selection (predictive value), and relate to survival outcomes (surrogacy). Evidence acquisition PubMed-based literature searches and abstracts through September 2011 provided the basis for this literature review as well as expert opinion. Evidence synthesis We address blood and urine-based biomarkers such as prostate-specific antigen, lactate dehydrogenase, total and bone alkaline phosphatase and other bone turnover markers, hemoglobin, and circulating tumor cells in the context of prognosis, prediction, and patient selection for therapy. Given the inherent problems associated with defining progression-free survival in CRPC, the importance of biomarker development and the needed steps are highlighted. We place the discussion of bio-markers within the context of the design/intent of a trial and mechanism of action of a given systemic therapy. We discuss novel biomarker development and the pathway for surrogate or predictive biomarkers to become credentialed as useful tests that inform therapeutic decisions. Conclusions A greater understanding of

  4. Phase II trial of RAD001 and bicalutamide for castration-resistant prostate cancer.

    PubMed

    Nakabayashi, Mari; Werner, Lilian; Courtney, Kevin D; Buckle, Geoffrey; Oh, William K; Bubley, Glen J; Hayes, Julia H; Weckstein, Douglas; Elfiky, Aymen; Sims, Danny M; Kantoff, Philip W; Taplin, Mary-Ellen

    2012-12-01

    Study Type--Therapy (cohort) Level of Evidence 2a. What's known on the subject? and What does the study add? Despite expanding treatment options for castration-resistant prostate cancer (CRPC), therapies with long response duration remain intangible due to prostate cancer cells' natural ability to develop iterative resistance. Androgen receptor (AR) signaling has been shown to play a critical role in CRPC and its expression is regulated by the PI3K-Akt pathway. Thus inhibition of AR signalling and PI3K-Akt-mTOR (a downstream mediator of the PI3K-Akt pathway) pathway is a logical combination in CRPC and we report a phase II trial of RAD001 and bicalutamide. Our study is the first clinical trial report of an AR inhibitor of PI3K-Akt-mTOR. The AR pathway and the PI3K-Akt-mTOR pathway are two of the most relevant growth pathway for CRPC. Despite low efficacy results from our trial there will be significant interest in the field for these data (dose, schedule, response, toxicity, trial design) as newer generations of both AR inhibitors and PI3K-Akt-mTOR inhibitors are in development and likely will be tested in combination in CRPC. • To determine best overall response and duration of response of RAD001, a selective inhibitor of mammalian target of rapamycin, in combination with bicalutamide in castration-resistant prostate cancer (CRPC). • To characterize the toxicity profile of RAD001 in combination with bicalutamide in patients with CRPC. • A phase II study was conducted to explore the efficacy and tolerability of RAD001 (10 mg daily) in combination with bicalutamide (50 mg daily) in men with progressive CRPC. • The primary endpoint was a composite of prostate-specific antigen (PSA) level and measurable disease response by standard criteria. • This single-stage trial with a sample size of 38 eligible patients provided 90% power to differentiate a response rate of ≥ 40% from a response rate of ≤ 20%, as expected for bicalutamide alone (α= 0.10, power = 0

  5. Targeting amino acid transport in metastatic castration-resistant prostate cancer: effects on cell cycle, cell growth, and tumor development.

    PubMed

    Wang, Qian; Tiffen, Jessamy; Bailey, Charles G; Lehman, Melanie L; Ritchie, William; Fazli, Ladan; Metierre, Cynthia; Feng, Yue Julie; Li, Estelle; Gleave, Martin; Buchanan, Grant; Nelson, Colleen C; Rasko, John E J; Holst, Jeff

    2013-10-02

    L-type amino acid transporters (LATs) uptake neutral amino acids including L-leucine into cells, stimulating mammalian target of rapamycin complex 1 signaling and protein synthesis. LAT1 and LAT3 are overexpressed at different stages of prostate cancer, and they are responsible for increasing nutrients and stimulating cell growth. We examined LAT3 protein expression in human prostate cancer tissue microarrays. LAT function was inhibited using a leucine analog (BCH) in androgen-dependent and -independent environments, with gene expression analyzed by microarray. A PC-3 xenograft mouse model was used to study the effects of inhibiting LAT1 and LAT3 expression. Results were analyzed with the Mann-Whitney U or Fisher exact tests. All statistical tests were two-sided. LAT3 protein was expressed at all stages of prostate cancer, with a statistically significant decrease in expression after 4-7 months of neoadjuvant hormone therapy (4-7 month mean = 1.571; 95% confidence interval = 1.155 to 1.987 vs 0 month = 2.098; 95% confidence interval = 1.962 to 2.235; P = .0187). Inhibition of LAT function led to activating transcription factor 4-mediated upregulation of amino acid transporters including ASCT1, ASCT2, and 4F2hc, all of which were also regulated via the androgen receptor. LAT inhibition suppressed M-phase cell cycle genes regulated by E2F family transcription factors including critical castration-resistant prostate cancer regulatory genes UBE2C, CDC20, and CDK1. In silico analysis of BCH-downregulated genes showed that 90.9% are statistically significantly upregulated in metastatic castration-resistant prostate cancer. Finally, LAT1 or LAT3 knockdown in xenografts inhibited tumor growth, cell cycle progression, and spontaneous metastasis in vivo. Inhibition of LAT transporters may provide a novel therapeutic target in metastatic castration-resistant prostate cancer, via suppression of mammalian target of rapamycin complex 1 activity and M-phase cell cycle genes.

  6. Wnt signaling in castration-resistant prostate cancer: implications for therapy

    PubMed Central

    Yokoyama, Noriko N; Shao, Shujuan; Hoang, Bang H; Mercola, Dan; Zi, Xiaolin

    2014-01-01

    Increasing evidence has indicated that Wnt signaling plays complex roles in castration resistant prostate cancer (CRPC). Although not all data were consistent, β-catenin nuclear localization and its co-localization with androgen receptor (AR) were more frequently observed in CRPC compared to hormone naïve prostate cancer. This direct interaction between AR and β-catenin seemed to elicit a specific expression of a set of target genes in low androgen conditions in CRPC. Paracrine Wnt signaling also was shown to aid resistance to chemotherapy and androgen deprivation therapy. Results from the next generation sequencing studies (i.e. RNA-seq and whole exosome sequcing) of CRPC specimens have identified the Wnt pathway as one of the top signaling pathways with significant genomic alterations in CRPC, whereas, Wnt pathway alterations were virtually absent in hormone naïve primary prostate cancer. Furthermore, Wnt signaling has been suggested to play an important role in cancer stem cell functions in prostate cancer recurrence and resistance to androgen deprivation therapy. Therefore, in this review we have summarized existing knowledge regarding potential roles of Wnt signaling in CRPC and underline Wnt signaling as a potential therapeutic target for CRPC. Further understanding of Wnt signaling in castration resistance may eventually contribute new insights into possible treatment options for this incurable disease. PMID:25143959

  7. Immunotherapy in castration-resistant prostate cancer: integrating sipuleucel-T into our current treatment paradigm.

    PubMed

    Garcia, Jorge A; Dreicer, Robert

    2011-03-01

    The availability of several novel antibodies, coupled with viral, DNA, and dendritic-cell vaccines, has renewed interest in immunotherapeutic approaches to the treatment of advanced prostate cancer. Although promising, none of these approaches have led to major clinical activity, and in the case of cell-based immunotherapy with GVAX, new concerns about safety arose when this therapy was used in the castration-resistant setting. A more attractive yet toxic approach has also utilized a check-point blockade with CTLA-4 antibodies. Although initial clinical efficacy has been observed, toxicity appears to be the major limitation of its use in prostate cancer. Sipuleucel-T (Provenge) is an autologous active cellular immunotherapy product that includes autologous dendritic cells pulsed ex vivo with PAP2024, a recombinant fusion protein made of prostatic acid phosphataase (PAP) and granulocyte-macrophage colony-stimulating factor (GM-CSF). Despite the lack of objective anti-tumor activity seen with sipuleucel-T, a recently reported phase III trial demonstrated a significant improvement in the overall survival of men with asymptomatic, minimally symptomatic metastatic castration-resistant prostate cancer (CRPC). This agent is the first FDA-approved novel immunotherapeutic compound for the treatment of a solid malignancy. A better understanding of how clinicians should incorporate this novel agent into the current management of CRPC is needed.

  8. Overcoming Autophagy to Induce Apoptosis in Castration Resistant Prostate Cancer

    DTIC Science & Technology

    2015-10-01

    of this study and the results proved that autophagy is the escape mechanism for tumor cells when challenged by small molecule inhibitors such as Src...Autophagy Blockade Sensitizes Prostate Cancer Cells towards Src Family Kinase Inhibitors . Genes Cancer, 2010. 1(1): p. 40-9. 6. Gillman, P.K., Tricyclic... inhibitor saracatinib or the androgen receptor signaling inhibitor enzalutamide. When stresses such as metabolic and genotoxic stress caused by

  9. PSMA-Based Radioligand Therapy for Metastatic Castration-Resistant Prostate Cancer: The Bad Berka Experience Since 2013.

    PubMed

    Kulkarni, Harshad R; Singh, Aviral; Schuchardt, Christiane; Niepsch, Karin; Sayeg, Manal; Leshch, Yevgeniy; Wester, Hans-Juergen; Baum, Richard P

    2016-10-01

    A potential milestone in personalized nuclear medicine is theranostics of metastatic castration-resistant prostate cancer (mCRPC) based on molecular imaging using PET/CT with (68)Ga-labeled prostate-specific membrane antigen (PSMA) ligands and molecular radiotherapy using PSMA-targeted radioligand therapy (PRLT) with (177)Lu-PSMA ligands. (68)Ga-PSMA PET/CT enables accurate detection of mCRPC lesions with high diagnostic sensitivity and specificity and provides quantitative and reproducible data that can be used to select patients for PRLT and therapeutic monitoring. Our comprehensive experience over the last 3 years using different radioligands indicates that PRLT is highly effective for the treatment of mCRPC, even in advanced cases, and potentially lends a significant benefit to overall and progression-free survival. Additionally, significant improvement in clinical symptoms and excellent palliation of pain can be achieved. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  10. Non-Coding RNAs in Castration-Resistant Prostate Cancer: Regulation of Androgen Receptor Signaling and Cancer Metabolism

    PubMed Central

    Shih, Jing-Wen; Wang, Ling-Yu; Hung, Chiu-Lien; Kung, Hsing-Jien; Hsieh, Chia-Ling

    2015-01-01

    Hormone-refractory prostate cancer frequently relapses from therapy and inevitably progresses to a bone-metastatic status with no cure. Understanding of the molecular mechanisms conferring resistance to androgen deprivation therapy has the potential to lead to the discovery of novel therapeutic targets for type of prostate cancer with poor prognosis. Progression to castration-resistant prostate cancer (CRPC) is characterized by aberrant androgen receptor (AR) expression and persistent AR signaling activity. Alterations in metabolic activity regulated by oncogenic pathways, such as c-Myc, were found to promote prostate cancer growth during the development of CRPC. Non-coding RNAs represent a diverse family of regulatory transcripts that drive tumorigenesis of prostate cancer and various other cancers by their hyperactivity or diminished function. A number of studies have examined differentially expressed non-coding RNAs in each stage of prostate cancer. Herein, we highlight the emerging impacts of microRNAs and long non-coding RNAs linked to reactivation of the AR signaling axis and reprogramming of the cellular metabolism in prostate cancer. The translational implications of non-coding RNA research for developing new biomarkers and therapeutic strategies for CRPC are also discussed. PMID:26690121

  11. Non-Coding RNAs in Castration-Resistant Prostate Cancer: Regulation of Androgen Receptor Signaling and Cancer Metabolism.

    PubMed

    Shih, Jing-Wen; Wang, Ling-Yu; Hung, Chiu-Lien; Kung, Hsing-Jien; Hsieh, Chia-Ling

    2015-12-04

    Hormone-refractory prostate cancer frequently relapses from therapy and inevitably progresses to a bone-metastatic status with no cure. Understanding of the molecular mechanisms conferring resistance to androgen deprivation therapy has the potential to lead to the discovery of novel therapeutic targets for type of prostate cancer with poor prognosis. Progression to castration-resistant prostate cancer (CRPC) is characterized by aberrant androgen receptor (AR) expression and persistent AR signaling activity. Alterations in metabolic activity regulated by oncogenic pathways, such as c-Myc, were found to promote prostate cancer growth during the development of CRPC. Non-coding RNAs represent a diverse family of regulatory transcripts that drive tumorigenesis of prostate cancer and various other cancers by their hyperactivity or diminished function. A number of studies have examined differentially expressed non-coding RNAs in each stage of prostate cancer. Herein, we highlight the emerging impacts of microRNAs and long non-coding RNAs linked to reactivation of the AR signaling axis and reprogramming of the cellular metabolism in prostate cancer. The translational implications of non-coding RNA research for developing new biomarkers and therapeutic strategies for CRPC are also discussed.

  12. Inhibition of Pten deficient Castration Resistant Prostate Cancer by Targeting of the SET - PP2A Signaling axis

    PubMed Central

    Hu, Xiaoyong; Garcia, Consuelo; Fazli, Ladan; Gleave, Martin; Vitek, Michael P.; Jansen, Marilyn; Christensen, Dale; Mulholland, David J

    2015-01-01

    The PP2A signaling axis regulates multiple oncogenic drivers of castration resistant prostate cancer (CRPC). We show that targeting the endogenous PP2A regulator, SET (I2PP2A), is a viable strategy to inhibit prostate cancers that are resistant to androgen deprivation therapy. Our data is corroborated by analysis of prostate cancer patient cohorts showing significant elevation of SET transcripts. Tissue microarray analysis reveals that elevated SET expression correlates with clinical cancer grading, duration of neoadjuvant hormone therapy (NHT) and time to biochemical recurrence. Using prostate regeneration assays, we show that in vivo SET overexpression is sufficient to induce hyperplasia and prostatic intraepithelial neoplasia. Knockdown of SET induced significant reductions in tumorgenesis both in murine and human xenograft models. To further validate SET as a therapeutic target, we conducted in vitro and in vivo treatments using OP449 - a recently characterized PP2A-activating drug (PAD). OP449 elicits robust anti-cancer effects inhibiting growth in a panel of enzalutamide resistant prostate cancer cell lines. Using the Pten conditional deletion mouse model of prostate cancer, OP449 potently inhibited PI3K-Akt signaling and impeded CRPC progression. Collectively, our data supports a critical role for the SET-PP2A signaling axis in CRPC progression and hormone resistant disease. PMID:26563471

  13. Inhibition of Pten deficient Castration Resistant Prostate Cancer by Targeting of the SET - PP2A Signaling axis.

    PubMed

    Hu, Xiaoyong; Garcia, Consuelo; Fazli, Ladan; Gleave, Martin; Vitek, Michael P; Jansen, Marilyn; Christensen, Dale; Mulholland, David J

    2015-11-13

    The PP2A signaling axis regulates multiple oncogenic drivers of castration resistant prostate cancer (CRPC). We show that targeting the endogenous PP2A regulator, SET (I2PP2A), is a viable strategy to inhibit prostate cancers that are resistant to androgen deprivation therapy. Our data is corroborated by analysis of prostate cancer patient cohorts showing significant elevation of SET transcripts. Tissue microarray analysis reveals that elevated SET expression correlates with clinical cancer grading, duration of neoadjuvant hormone therapy (NHT) and time to biochemical recurrence. Using prostate regeneration assays, we show that in vivo SET overexpression is sufficient to induce hyperplasia and prostatic intraepithelial neoplasia. Knockdown of SET induced significant reductions in tumorgenesis both in murine and human xenograft models. To further validate SET as a therapeutic target, we conducted in vitro and in vivo treatments using OP449 - a recently characterized PP2A-activating drug (PAD). OP449 elicits robust anti-cancer effects inhibiting growth in a panel of enzalutamide resistant prostate cancer cell lines. Using the Pten conditional deletion mouse model of prostate cancer, OP449 potently inhibited PI3K-Akt signaling and impeded CRPC progression. Collectively, our data supports a critical role for the SET-PP2A signaling axis in CRPC progression and hormone resistant disease.

  14. AR-V7 Transcripts in Whole Blood RNA of Patients with Metastatic Castration Resistant Prostate Cancer Correlate with Response to Abiraterone Acetate.

    PubMed

    Todenhöfer, Tilman; Azad, Arun; Stewart, Craig; Gao, Jian; Eigl, Bernhard J; Gleave, Martin E; Joshua, Anthony M; Black, Peter C; Chi, Kim N

    2017-01-01

    The expression of AR-V7 (androgen receptor splice variant) 7 in circulating tumor cells has been associated with resistance to abiraterone and enzalutamide in patients with metastatic castration resistant prostate cancer. We used a sensitive, whole blood reverse transcriptase-polymerase chain reaction assay that does not require circulating tumor cell enrichment to correlate outcomes of abiraterone with whole blood expression of AR-V7 and other prostate cancer associated transcripts. We assessed the expression of AR-V7, FOXA1, GRHL2, HOXB13, KLK2, KLK3 and TMPRSS2:ERG mRNA in 2.5 ml whole blood from each of 27 patients with metastatic castration resistant prostate cancer and 33 controls without cancer as the discovery cohort. Cycle threshold values of controls with the highest gene expression were set as the threshold for a positive test. Thresholds were then applied to a validation cohort of 37 patients with metastatic castration resistant prostate cancer who were commencing abiraterone. Gene expression was correlated with the prostate specific antigen response rate using the chi-square test, and with time to prostate specific antigen progression and overall survival using the log rank test. In the discovery cohort 3 of 27 patients (11.1%) with metastatic castration resistant prostate cancer were AR-V7 positive vs 4 of 37 (10.8%) in the validation cohort. In the validation cohort patients with a positive AR-V7 test had a lower prostate specific antigen response rate (0% vs 42%, p = 0.27) together with shorter median prostate specific antigen progression (0.7 vs 4.0 months, p <0.001) and median overall survival (5.5 vs 22.1 months, p <0.001). Reverse transcriptase-polymerase chain reaction detection of AR-V7 transcripts in whole blood was associated with inferior outcomes in patients treated with abiraterone. These results reinforce the potential usefulness of AR-V7 as a prognostic and predictive biomarker for metastatic castration resistant prostate cancer

  15. Investigating BRCA Mutations: A Breakthrough in Precision Medicine of Castration-Resistant Prostate Cancer.

    PubMed

    Modena, Alessandra; Iacovelli, Roberto; Scarpa, Aldo; Brunelli, Matteo; Ciccarese, Chiara; Fantinel, Emanuela; Bimbatti, Davide; Massari, Francesco; Martignoni, Guido; Tortora, Giampaolo

    2016-10-01

    Despite the development of novel effective therapeutic strategies, metastatic castration-resistant prostate cancer (mCRPC) remains a disease with a lethal course and a high biological and molecular heterogeneity. To date, germline mutations in the BRCA gene represent one of the main risk factors for developing prostate cancer, with a strong association with aggressive phenotype and poor clinical outcomes. A better understanding of the genomic landscape of prostate cancer has strengthened the idea that "synthetic lethality" of this disease might be useful in cancer-drug discovery, focusing on agents such as platinum compounds and poly (adenosine diphosphate [ADP]-ribose) polymerase inhibitors (PARPi). In this review, we summarize the main data available on BRCA mutations and discuss the clinical implications of these genomic aberrations in the management of prostate cancer, stressing the need to identify prognostic and predictive biomarkers and to deeply understand the mechanisms of treatment resistance, in order to maximize personalized medicine protocols and therefore clinical benefit.

  16. Role of Chemotherapy and Mechanisms of Resistance to Chemotherapy in Metastatic Castration-Resistant Prostate Cancer

    PubMed Central

    Lohiya, Vipin; Aragon-Ching, Jeanny B.; Sonpavde, Guru

    2016-01-01

    Chemotherapy using the taxanes, docetaxel and cabazitaxel, remains an important therapeutic option in metastatic castration-resistant prostate cancer (CRPC). However, despite the survival benefits afforded by these agents, the survival increments are modest and resistance occurs universally. Efforts to overcome resistance to docetaxel by combining with biologic agents have heretofore been unsuccessful. Indeed, resistance to these taxanes is also associated with cross-resistance to the antiandrogen drugs, abiraterone and enzalutamide. Here, we discuss the various mechanisms of resistance to chemotherapy in metastatic CRPC and the potential role of emerging regimens and agents in varying clinical phases of development. PMID:27773999

  17. Dual-Targeting of AR and Akt Pathways by Berberine in Castration-Resistant Prostate Cancer

    DTIC Science & Technology

    2016-10-01

    Ther 2013; 12: 1629-37. [25] Zhan Y, Cao B, Qi Y, Liu S, Zhang Q, Zhou W, Xu D, Lu H, Sartor O, Kong W, Zhang H, Dong Y. Methylselenol prodrug... Methylselenol prodrug enhances MDV3100 efficacy for treatment of castration-resistant prostate cancer. Int.J.Cancer. 2013; 133: 2225-33. 22. Tran C, Ouk S...2005;4:1047–55. 28. Zhan Y, Cao B, Qi Y, Liu S, Zhang Q, ZhouW, et al. Methylselenol prodrug enhances MDV3100 efficacy for treatment of castration

  18. Radium 223: how can we optimize this new tool for metastatic castration-resistant prostate cancer?

    PubMed

    Dorff, Tanya Barauskas; Gross, Mitchell E

    2015-01-01

    Radium 223 is an alpha-emitting intravenous radiotherapy approved for the treatment of men with metastatic castration-resistant prostate cancer (mCRPC). The approved indication covers men with pain from bony metastatic disease and no visceral involvement; however, questions remain as to optimal patient selection and timing of this treatment relative to other life-extending therapies for mCRPC. Limited data exist to guide clinicians on how to position radium 223 in the therapeutic sequence, however, some theoretical considerations and data derived from the ALSYMPCA trial populations pre- and postdocetaxel will be outlined. Subgroup analyses may provide some insight into patient selection.

  19. Radium-223 chloride: a new treatment option for metastatic castration-resistant prostate carcinoma.

    PubMed

    Pinto, Alvaro; Cruz, Patricia

    2012-12-01

    In the last few years, the treatment of castration-resistant prostate carcinoma (CRPC) has changed completely. The approval of docetaxel and subsequent investigation in this field have led to development of new agents that have demonstrated an improvement in overall survival in the post-docetaxel setting, such as cabazitaxel and abiraterone. Radium-223 chloride is a radioisotope that has recently shown efficacy after docetaxel and in patients unfit for docetaxel, with improvements in overall survival and the time to the first skeletal-related event, compared with placebo, without increasing toxicity. These findings have made this agent a new option for treatment of these patients in the near future.

  20. GRP78-targeted nanotherapy against castrate-resistant prostate cancer cells expressing membrane GRP78.

    PubMed

    Delie, Florence; Petignat, Patrick; Cohen, Marie

    2013-12-01

    Glucose-regulated protein 78, GRP78, is a chaperone protein mainly located in the endoplasmic reticulum (ER) of normal cells. In stress conditions, GRP78 is overexpressed and in different cancer cell types, it is expressed at the cell surface, whereas it stays intracellular in non-cancerous cells. Therefore, it appears as a strategic target to recognize malignant cells. Prostate cancer is one of the most diagnosed cancers in men. The development of castrate resistant tumors and the resistance to chemotherapy frequently occur. The carboxy-terminal ER retention domain is defined by the KDEL amino acid sequence. We developed anti-KDEL functionalized polymeric nanoparticles (NPs) loaded with paclitaxel (Tx) to specifically target prostate cancer cells expressing GRP78. The sensitivity to Tx in different formulations was compared in three prostate cell lines: PNT1B, a normal cell line, PC3, a cancer cell line faintly expressing GRP78 at its surface, and DU145, a cancer cell line expressing GRP78 at its cell surface. Our results show that the targeted formulation significantly increases Tx sensitivity of cell line expressing GRP78 at its surface compared to other treatments suggesting the added value of GRP78 targeted therapy for castrate resistant tumor which expresses GRP78 at its cell surface.

  1. Osteoblasts promote castration-resistant prostate cancer by altering intratumoral steroidogenesis.

    PubMed

    Hagberg Thulin, Malin; Nilsson, Maria E; Thulin, Pontus; Céraline, Jocelyn; Ohlsson, Claes; Damber, Jan-Erik; Welén, Karin

    2016-02-15

    The skeleton is the preferred site for prostate cancer (PC) metastasis leading to incurable castration-resistant disease. The increased expression of genes encoding steroidogenic enzymes found in bone metastatic tissue from patients suggests that up-regulated steroidogenesis might contribute to tumor growth at the metastatic site. Because of the overall sclerotic phenotype, we hypothesize that osteoblasts regulate the intratumoral steroidogenesis of castration resistant prostate cancer (CRPC) in bone. We here show that osteoblasts alter the steroidogenic transcription program in CRPC cells, closely mimicking the gene expression pattern described in CRPC. Osteoblast-stimulated LNCaP-19 cells displayed an increased expression of genes encoding for steroidogenic enzymes (CYP11A1, HSD3B1, and AKR1C3), estrogen signaling-related genes (CYP19A1, and ESR2), and genes for DHT-inactivating enzymes (UGT2B7, UGT2B15, and UGT2B17). The observed osteoblast-induced effect was exclusive to osteogenic CRPC cells (LNCaP-19) in contrast to osteolytic PC-3 and androgen-dependent LNCaP cells. The altered steroid enzymatic pattern was specific for the intratibial tumors and verified by immunohistochemistry in tissue specimens from LNCaP-19 xenograft tumors. Additionally, the overall steroidogenic effect was reflected by corresponding levels of progesterone and testosterone in serum from castrated mice with intratibial xenografts. A bi-directional interplay was demonstrated since both proliferation and Esr2 expression of osteoblasts were induced by CRPC cells in steroid-depleted conditions. Together, our results demonstrate that osteoblasts are important mediators of the intratumoral steroidogenesis of CRPC and for castration-resistant growth in bone. Targeting osteoblasts may therefore be important in the development of new therapeutic approaches.

  2. Vav3 enhances androgen receptor splice variant activity and is critical for castration-resistant prostate cancer growth and survival.

    PubMed

    Peacock, Stephanie O; Fahrenholtz, Cale D; Burnstein, Kerry L

    2012-12-01

    Advanced or metastatic prostate cancer is treated by androgen deprivation; however, patients inevitably relapse with castration-resistant prostate cancer (CRPC). CRPC remains dependent on androgen receptor (AR) signaling, which may include constitutive, ligand-independent action of naturally occurring AR splice variants. For example, the AR splice variant AR3 (also termed AR-V7) is expressed in CRPC and is linked to poor prognosis. Vav3, a Rho GTPase guanine nucleotide exchange factor, is an AR coactivator that is up-regulated in human prostate cancer compared with benign tissue and in preclinical models of CRPC. Vav3 confers castration-resistant growth to androgen-dependent human prostate cancer cells. Despite the importance of AR coactivators in promoting CRPC, the potential role of these regulatory proteins in modulating AR splice variant activity is unknown. We examined the contributions of Vav3 to AR activity in two CRPC cell lines that naturally express relatively high levels of Vav3 and AR3. Vav3 or AR3 knockdown greatly attenuated cell proliferation, soft agar growth, and ligand-independent AR activity. Vav3 potently enhanced the transcriptional activity of AR3 and another clinically relevant AR splice variant, ARv567es. Vav3 knockdown resulted in lowered nuclear AR3 levels, whereas total AR3 levels remained similar. Conversely, overexpression of Vav3 resulted in increased nuclear AR3. Coimmunoprecipitation revealed that AR3 and Vav3 interact. These novel data demonstrating physical and functional interactions between Vav3, a unique AR coactivator, and an AR splice variant provide insights into the mechanisms by which Vav3 exploits and enhances AR signaling in the progression to CRPC.

  3. Bmi1 marks distinct castration-resistant luminal progenitor cells competent for prostate regeneration and tumour initiation

    PubMed Central

    Yoo, Young A.; Roh, Meejeon; Naseem, Anum F.; Lysy, Barbara; Desouki, Mohamed M.; Unno, Kenji; Abdulkadir, Sarki A.

    2016-01-01

    Identification of defined cell populations with stem/progenitor properties is key for understanding prostate development and tumorigenesis. Here we show that the polycomb repressor protein Bmi1 marks a population of castration-resistant luminal epithelial cells enriched in the mouse proximal prostate. We employ lineage tracing to show that these castration-resistant Bmi1-expressing cells (or CARBs) are capable of tissue regeneration and self-renewal. Notably, CARBs are distinct from the previously described luminal castration-resistant Nkx3.1-expressing cells (CARNs). CARBs can serve as a prostate cancer cell-of-origin upon Pten deletion, yielding luminal prostate tumours. Clonal analysis using the R26R-confetti allele indicates preferential tumour initiation from CARBs localized to the proximal prostate. These studies identify Bmi1 as a marker for a distinct population of castration-resistant luminal epithelial cells enriched in the proximal prostate that can serve as a cell of origin for prostate cancer. PMID:27703144

  4. Molecular Indicators of Castration-Resistant Prostate Cancer

    DTIC Science & Technology

    2014-10-01

    confirmed on computed tomography (CT) or bone scanning with technetium -99m–labeled methylene diphosphonate. Patients had to have three or more rising... technetium -99m bone scanning were performed every 2 to 4 months. Therapy with enzalutamide or abiraterone was continued until PSA progression, clinical or

  5. Targeting cancer stem cell in castration resistant prostate cancer

    PubMed Central

    Yun, Eun-Jin; Zhou, Jiancheng; Lin, Chun-Jung; Hernandez, Elizabeth; Fazli, Ladan; Gleave, Martin; Hsieh, Jer-Tsong

    2015-01-01

    Purpose Clinical evidence suggests an increased CSC in tumor mass may contribute to the failure of conventional therapies since CSCs seem to be more resistant than differentiated tumor cells. Thus, unveiling the mechanism regulating CSCs and candidate target molecules will provide new strategy to cure the patients. Experimental design The stem-like cell properties were determined by a prostasphere assay, and dye exclusion assay. To find critical stem cell marker and reveal regulation mechanism, basic biochemical and molecular biological methods such as qRT-PCR, Western blot, reporter gene assay and chromatin immunoprecipitation assay were employed. In addition, to determine the effect of combination therapy targeting both CSCs and its progeny, in vitro MTT assay and in vivo xenograft model was used. Results We demonstrate immortalized normal human prostate epithelial cells, appeared non-tumorigenic in vivo, become tumorigenic and acquire stem cell phenotype after knocking down a tumor suppressor gene. Also, those stem-like cells increase chemoresistance to conventional anti-cancer reagent. Mechanistically, we unveil that Wnt signaling is a key pathway regulating well-known stem cell marker CD44 by directly interacting to the promoter. Thus, by targeting CSCs using Wnt inhibitors synergistically enhances the efficacy of conventional drugs. Furthermore, the in vivo mice model bearing xenografts showed a robust inhibition of tumor growth after combination therapy. Conclusions Overall, this study provides strong evidence of CSC in CRPC. This new combination therapy strategy targeting CSC could significantly enhance therapeutic efficacy of current chemotherapy regimen only targeting non-CSC cells. PMID:26490309

  6. Phase 1 Trial of High-Dose Exogenous Testosterone in Patients with Castration-Resistant Metastatic Prostate Cancer

    PubMed Central

    Morris, Michael J.; Huang, Daisy; Kelly, William K.; Slovin, Susan F.; Stephenson, Ryan D.; Eicher, Caitlin; Delacruz, Anthony; Curley, Tracy; Schwartz, Lawrence; Scher, Howard I.

    2009-01-01

    Background Growth of selected castration-resistant prostate cancer (CRPC) cell lines and animal models can be repressed by reexposure to androgens. Low doses of androgens, however, can stimulate tumor growth. Objective We performed a phase 1 clinical trial to determine the safety of high-dose exogenous testosterone in patients with castration-resistant metastatic prostate cancer (CRMPC). Design, setting, and participants Patients with progressive CRMPC who had been castrate for at least 1 yr received three times the standard replacement dose of transdermal testosterone. Intervention Cohorts of 3–6 patients received testosterone for 1 wk, 1 mo, or until disease progression. Measurements Toxicities, androgen levels, prostate-specific antigen (PSA) assays, computed tomography (CT) scans, bone scintigraphy, positron emission tomography (PET) scans, and metastatic tumor biopsy androgen receptor levels were assessed. Results and limitations Twelve patients were treated—three in cohorts 1 and 2 and six in cohort 3. No pain flares were noted. One patient came off study because of epidural disease, which was treated with radiation. Average testosterone levels were within normal limits, although dihydrotestosterone (DHT) levels were supraphysiologic in cohort 3. One patient achieved a PSA decline of >50% from baseline. No objective responses were seen. For cohort 3, median time on treatment was 84 d (range: 23–247 d). Conclusions We have demonstrated that patients with CRMPC can be safely treated in clinical trials using high-dose exogenous testosterone. Patients did not, on average, achieve sustained supraphysiologic serum testosterone levels. Future studies should employ strategies to maximize testosterone serum levels, use contemporary methods of identifying patients with androgen receptor overexpression, and utilize PSA Working Group II Consensus Criteria clinical trial end points. PMID:19375217

  7. A novel HSP90 inhibitor delays castrate resistant prostate cancer without altering serum PSA levels and inhibits osteoclastogenesis

    PubMed Central

    Lamoureux, Francois; Thomas, Christian; Yin, Min-Jean; Kuruma, Hidetoshi; Fazli, Ladan; Gleave, Martin E; Zoubeidi, Amina

    2015-01-01

    Purpose Prostate cancer responds initially to anti-androgen therapies, however, progression to castration resistant disease frequently occurs. Therefore there is an urgent need for novel therapeutic agents that can prevent the emergence of castration resistant prostate cancer (CRPC). Hsp90 is a molecular chaperone involved in the stability of many client proteins including Akt and androgen receptor (AR). 17-AAG have been reported to inhibit tumor growth in various cancers, however induces tumor progression in the bone microenvironment. Methods Cell growth, apoptosis, and AR transactivation were examined by crystal violet assay, flow cytometry and luciferase assays respectively. The consequence of HSP90 therapy in vivo was evaluated in LNCaP xenograft model. The consequence of PF-04928473 therapy on bone metastasis was studied using an osteoclastogenesis in vitro assay. Results PF-04928473 inhibits cell growth in a panel of prostate cancer cells, induces cell cycle arrest at sub-G1 and leads to apoptosis and increased caspase-3 activity. These biologic events were accompanied by decreased activation of Akt and Erk as well as decreased expression of Her2, and decreased AR expression and activation in vitro. In contrast to 17-AAG, PF-04928473 abrogates RANKL-induced osteoclast differentiation by affecting NF-kB activation and Src phosphorylation. Finally, PF-04929113 inhibited tumor growth and prolonged survival compared to controls. Surprisingly, PF-04929113 did not reduce serum PSA levels in vivo in parallel these decreases in tumor volume. Conclusion These data identify significant anti-cancer activity of PF-04929113 in CRPC but suggest that serum PSA may not prove useful as pharmaco-dynamic tool for this drug. PMID:21349995

  8. Sipuleucel-T in patients with metastatic castration-resistant prostate cancer: an insight for oncologists.

    PubMed

    Garcia, Jorge A

    2011-03-01

    Sipuleucel-T represents a novel immunotherapeutic compound designed to stimulate an immune response against castration-resistant prostate cancer (CRPC). Sipuleucel-T is an autologous active cellular immunotherapy product, which includes autologous dendritic cells pulsed ex vivo with PAP2024, a recombinant fusion protein made of prostatic acid phosphatase and granulocyte-macrophage colony-stimulating factor. Despite the lack of prostate-specific antigen and objective response, a recent phase III randomized trial demonstrated a significant improvement in overall survival in asymptomatic and minimally symptomatic CRPC patients. This review summarizes the clinical development of Sipuleucel-T in CRPC that led to the regulatory approval of this compound in the USA.

  9. Cabazitaxel: a novel second-line treatment for metastatic castration-resistant prostate cancer

    PubMed Central

    Paller, Channing J; Antonarakis, Emmanuel S

    2011-01-01

    Until recently, patients with castration-resistant prostate cancer (CRPC) had limited therapeutic options once they became refractory to docetaxel chemotherapy, and no treatments improved survival. This changed in June 2010 when the Food and Drug Administration (FDA) approved cabazitaxel as a new option for patients with CRPC whose disease progresses during or after docetaxel treatment. For most of these patients, cabazitaxel will now replace mitoxantrone (a drug that was FDA-approved because of its palliative effects) as the treatment of choice for docetaxel-refractory disease. The approval of cabazitaxel was based primarily on the TROPIC trial, a large (n = 755) randomized Phase III study showing an overall median survival benefit of 2.4 months for men with docetaxel-pretreated metastatic CRPC receiving cabazitaxel (with prednisone) compared to mitoxantrone (with prednisone). Cabazitaxel is a novel tubulin-binding taxane that differs from docetaxel because of its poor affinity for P-glycoprotein (P-gp), an ATP-dependent drug efflux pump. Cancer cells that express P-gp become resistant to taxanes, and the effectiveness of docetaxel can be limited by its high substrate affinity for P-gp. Preclinical and early clinical studies show that cabazitaxel retains activity in docetaxel-resistant tumors, and this was confirmed by the TROPIC study. Common adverse events with cabazitaxel include neutropenia (including febrile neutropenia) and diarrhea, while neuropathy was rarely observed. Thus, the combination of cabazitaxel and prednisone is an important new treatment option for men with docetaxel-refractory metastatic CRPC, but this agent should be administered cautiously and with appropriate monitoring (especially in men at high risk of neutropenic complications). PMID:21448449

  10. Targeting the androgenic pathway in elderly patients with castration-resistant prostate cancer

    PubMed Central

    Roviello, Giandomenico; Cappelletti, Maria Rosa; Zanotti, Laura; Gobbi, Angela; Senti, Chiara; Bottini, Alberto; Ravelli, Andrea; Bonetta, Alberto; Paganini, Giovanni; Generali, Daniele

    2016-01-01

    Abstract Background: The novel hormonal drugs have recently entered in the armamentarium of therapies for treatment of metastatic castration-resistant prostate cancer (CRPC). First reports are available for their use in elderly men with CRPC. Method: A meta-analysis of randomized controlled trials (RCTs) has been performed. PubMed, the Cochrane Library, and American Society of Clinical Oncology (ASCO) University Meeting were searched for data on the use of new hormonal treatment in elderly patients with CRPC. Results: Nine studies for a total of 3512 elderly patients were available for meta-analysis. Six studies reported outcomes of patients aged >75 years old while 2 studies reported on patients aged >70 years old. The pooled analysis of the androgen synthesis inhibitors revealed significantly increased overall survival (OS) due to antiandrogen agents compared with placebo or placebo and prednisone (hazard ratio (HR) for death: HR = 0.74, 95% CI: 0.67–0.82; P < 0.00001). Moreover, the new antiandrogenic therapy significantly improved the progression-free survival (HR = 0.45, 95% CI: 0.31–0.65; P < 0.0001). The incidence of any grade ≥3 adverse effect was only moderately higher during with the antiandrogenic therapy as compared to the control arms (response rate = 1.03, 95% CI: 0.88–1.20; P = 0.72). Conclusion: This study confirmed that agents targeting the androgen axis (i.e., enzalutamide, abiraterone) significantly prolonged OS in elderly men with CRPC. PMID:27787354

  11. Proteomic Profiling of Androgen-independent Prostate Cancer Cell Lines Reveals a Role for Protein S during the Development of High Grade and Castration-resistant Prostate Cancer

    PubMed Central

    Saraon, Punit; Musrap, Natasha; Cretu, Daniela; Karagiannis, George S.; Batruch, Ihor; Smith, Chris; Drabovich, Andrei P.; Trudel, Dominique; van der Kwast, Theodorus; Morrissey, Colm; Jarvi, Keith A.; Diamandis, Eleftherios P.

    2012-01-01

    Androgen deprivation constitutes the principal therapy for advanced and metastatic prostate cancers. However, this therapeutic intervention usually results in the transition to a more aggressive androgen-independent prostate cancer. The elucidation of molecular alterations during the progression to androgen independence is an integral step toward discovering more effective targeted therapies. With respect to identifying crucial mediators of this transition, we compared the proteomes of androgen-independent (PC3, DU145, PPC1, LNCaP-SF, and 22Rv1) and androgen-dependent (LNCaP and VCaP) and/or normal prostate epithelial (RWPE) cell lines using mass spectrometry. We identified more than 100 proteins that were differentially secreted in the androgen-independent cell lines. Of these, Protein S (PROS1) was elevated in the secretomes of all of the androgen-independent prostate cancer cell lines, with no detectable secretion in normal and androgen-dependent cell lines. Using quantitative PCR, we observed significantly higher (p < 0.05) tissue expression levels of PROS1 in prostate cancer samples, further indicating its importance in prostate cancer progression. Similarly, immunohistochemistry analysis revealed elevation of PROS1 in high grade prostate cancer (Gleason grade ≥8), and further elevation in castration-resistant metastatic prostate cancer lesions. We also observed its significant (p < 0.05) elevation in high grade prostate cancer seminal plasma samples. Taken together, these results show that PROS1 is elevated in high grade and castration-resistant prostate cancer and could serve as a potential biomarker of aggressive disease. PMID:22908226

  12. Optimal Sequencing of New Drugs in Metastatic Castration-Resistant Prostate Cancer: Dream or Reality?

    PubMed

    Caffo, Orazio; Lunardi, Andrea; Trentin, Chiara; Maines, Francesca; Veccia, Antonello; Galligioni, Enzo

    2016-01-01

    The availability of new drugs capable of improving the overall survival of patients with metastatic castration-resistant prostate cancer has led to the possibility of using them sequentially in the hope of obtaining a cumulative survival benefit. The new agents have already been administered as third-line treatments in patients who have previously received them as second line in everyday clinical practice, but the efficacy of this practice is not yet supported by clinical trial data, and evidence of possible cross-resistance has reinforced the debate concerning the best sequence to use in order to maximise the benefit. Furthermore, the situation is further complicated by the possibility of administering new hormonal agents to chemotherapy-naïve patients, and novel chemotherapeutic agents to hormone-sensitive patients. This article critically reviews the available data concerning the sequential use of new drugs, and discusses the real evidence concerning their optimal positioning in the therapeutic strategy of metastatic castration-resistant prostate cancer.

  13. MicroRNAs and Androgen Receptor 3′ Untranslated Region: A Missing Link in Castration-resistant Prostate Cancer?

    PubMed Central

    Sikand, Kavleen; Barik, Sailen; Shukla, Girish C.

    2012-01-01

    The ligand-activated transcription factor, androgen receptor (AR) plays a central role in the development and progression of prostate cancer. Prostate cancer initiates as an androgen-dependent disease and further accumulation of multiple sequential genetic and epigenetic alterations transform it into an aggressive, castration-resistant prostate cancer (CRPC). The molecular basis of the transition from androgen-dependent prostate cancer to CRPC remains unclear. However, it is apparent that AR plays a pivotal role in this alteration. The recent discovery that microRNAs (miRNAs) can target the function of AR suggests a functional role of these non-coding RNAs in the pathogenesis of prostate cancer. miRNAs usually function by targeting the 3′ untranslated region (UTR) of a mRNA by base-pairing interactions and modulate translation either by destabilizing the message or by repression of protein synthesis in actively translating ribosomes. Here, we discuss the potential molecular pathways through which AR targeting miRNAs may promote CRPC. Modulation of AR expression by miRNAs presents a novel therapeutic option for prostate cancer, albeit it will likely be used in combination with the existing therapies. PMID:22468168

  14. New radiopharmaceutical agents for the treatment of castration-resistant prostate cancer.

    PubMed

    Maffioli, L; Florimonte, L; Costa, D C; Correia Castanheira, J; Grana, C; Luster, M; Bodei, L; Chinol, M

    2015-12-01

    Prostate cancer (PCa) is the fourth most common cancer worldwide in terms of incidence and third among male, but is becoming the most common cancer in developed countries. In many patients the disease will progress despite of castration levels of testosterone, to become castration-resistant PCa (CRPC). Nearly all patients with CRPC show bone metastases. The treatment of patients with bony metastases has dramatically changed during the past three years because of new therapeutic approaches addressed to obtain pain control, reduced skeletal morbidity, and most importantly, increased survival rate. A possible therapy can be based also on the use of radiopharmaceuticals systemically administered to slow or reverse the bone metastatic progression. In facts bone-homing radiopharmaceuticals are taken up in areas of high bone turnover, including areas with high osteoblastic activity. Recently, a bone targeting radiopharmaceutical, Radium-223 dichloride was added to this group of drugs clearly representing a new generation of radiopharmaceutical in bone therapy. Clinical trials had shown that the treatment with Ra-223 allowed the reduction of the risk of death respect to placebo. No other radiometabolic treatment achieved such result, evidentiating the disease-modifying properties of this bone-homing radiopharmaceutical. In an effort to treat patients with disseminated PCa, who became resistant to hormonal therapy, molecular targets have been recently identified. Prostate specific membrane antigen (PSMA) is one attractive target for diagnosis and therapy of metastasized PCa since its expression levels are directly correlated to androgen independence, metastasis, and progression. Gastrin-releasing peptide receptors (GRPr) are also highly overexpressed in PCa. Numerous studies suggest the possibility of a high PCa-specific signal with radiolabeled bombesin analogs targeting GRPr. Low molecular weight peptides directed against these molecular targets have been radiolabeled

  15. Phase III Study of Cabozantinib in Previously Treated Metastatic Castration-Resistant Prostate Cancer: COMET-1.

    PubMed

    Smith, Matthew; De Bono, Johann; Sternberg, Cora; Le Moulec, Sylvestre; Oudard, Stéphane; De Giorgi, Ugo; Krainer, Michael; Bergman, Andries; Hoelzer, Wolfgang; De Wit, Ronald; Bögemann, Martin; Saad, Fred; Cruciani, Giorgio; Thiery-Vuillemin, Antoine; Feyerabend, Susan; Miller, Kurt; Houédé, Nadine; Hussain, Syed; Lam, Elaine; Polikoff, Jonathan; Stenzl, Arnulf; Mainwaring, Paul; Ramies, David; Hessel, Colin; Weitzman, Aaron; Fizazi, Karim

    2016-09-01

    Cabozantinib is an inhibitor of kinases, including MET and vascular endothelial growth factor receptors, and has shown activity in men with previously treated metastatic castration-resistant prostate cancer (mCRPC). This blinded phase III trial compared cabozantinib with prednisone in patients with mCRPC. Men with progressive mCRPC after docetaxel and abiraterone and/or enzalutamide were randomly assigned at a two-to-one ratio to cabozantinib 60 mg once per day or prednisone 5 mg twice per day. The primary end point was overall survival (OS). Bone scan response (BSR) at week 12 as assessed by independent review committee was the secondary end point; radiographic progression-free survival (rPFS) and effects on circulating tumor cells (CTCs), bone biomarkers, serum prostate-specific antigen (PSA), and symptomatic skeletal events (SSEs) were exploratory assessments. A total of 1,028 patients were randomly assigned to cabozantinib (n = 682) or prednisone (n = 346). Median OS was 11.0 months with cabozantinib and 9.8 months with prednisone (hazard ratio, 0.90; 95% CI, 0.76 to 1.06; stratified log-rank P = .213). BSR at week 12 favored cabozantinib (42% v 3%; stratified Cochran-Mantel-Haenszel P < .001). rPFS was improved in the cabozantinib group (median, 5.6 v 2.8 months; hazard ratio, 0.48; 95% CI, 0.40 to 0.57; stratified log-rank P < .001). Cabozantinib was associated with improvements in CTC conversion, bone biomarkers, and post-random assignment incidence of SSEs but not PSA outcomes. Grade 3 to 4 adverse events and discontinuations because of adverse events were higher with cabozantinib than with prednisone (71% v 56% and 33% v 12%, respectively). Cabozantinib did not significantly improve OS compared with prednisone in heavily treated patients with mCRPC and progressive disease after docetaxel and abiraterone and/or enzalutamide. Cabozantinib had some activity in improving BSR, rPFS, SSEs, CTC conversions, and bone biomarkers but not PSA outcomes. © 2016 by

  16. A phase 2 clinical trial of everolimus plus bicalutamide for castration-resistant prostate cancer.

    PubMed

    Chow, Helen; Ghosh, Paramita M; deVere White, Ralph; Evans, Christopher P; Dall'Era, Marc A; Yap, Stanley A; Li, Yueju; Beckett, Laurel A; Lara, Primo N; Pan, Chong-Xian

    2016-06-15

    The mammalian target of rapamycin (mTOR) pathway is up-regulated in castration-resistant prostate cancer (CRPC). Nevertheless, inhibition of mTOR is ineffective in inducing apoptosis in prostate cancer cells, likely because of the compensatory up-regulation of the androgen receptor (AR) pathway. Patients who were eligible for this study had to have progressive CRPC with serum testosterone levels <50 ng/dL. No prior bicalutamide (except to prevent flare) or everolimus was allowed. Treatment included oral bicalutamide 50 mg and oral everolimus 10 mg, both once daily, with a cycle defined as 4 weeks. The primary endpoint was the prostate-specific antigen (PSA) response (≥30% reduction) from baseline. A sample size of 23 patients would have power of 0.8 and an α error of .05 (1-sided) if the combination had a PSA response rate of 50% versus a historic rate of 25% with bicalutamide alone. Twenty-four patients were enrolled. The mean age was 71.1 years (range, 53.0-87.0 years), the mean PSA level at study entry was 43.4 ng/dL (range, 2.5-556.9 ng/dL), and the mean length of treatment was 8 cycles (range, 1.0-23.0 cycles). Of 24 patients, 18 had a PSA response (75%; 95% confidence interval [CI], 0.53-0.90), whereas 15 (62.5%; 95% CI, 0.41-0.81) had a PSA decrease ≥50%. The median overall survival was 28 months (95% CI, 14.1-42.7 months). Fourteen patients (54%; 95% CI, 0.37-0.78) developed grade 3 (13 patients) or grade 4 (1 patient with sepsis) adverse events that were attributable to treatment. The combination of bicalutamide and everolimus has encouraging efficacy in men with bicalutamide-naive CRPC, thus warranting further investigation. A substantial number of patients experienced everolimus-related toxicity. Cancer 2016;122:1897-904. © 2016 American Cancer Society. © 2016 American Cancer Society.

  17. Niclosamide inhibits androgen receptor variants expression and overcomes enzalutamide resistance in castration-resistant prostate cancer.

    PubMed

    Liu, Chengfei; Lou, Wei; Zhu, Yezi; Nadiminty, Nagalakshmi; Schwartz, Chad T; Evans, Christopher P; Gao, Allen C

    2014-06-15

    Enzalutamide, a second-generation antiandrogen, was recently approved for the treatment of castration-resistant prostate cancer (CRPC) in patients who no longer respond to docetaxel. Despite these advances that provide temporary respite, resistance to enzalutamide occurs frequently. Androgen receptor (AR) splice variants such as AR-V7 have recently been shown to drive castration-resistant growth and resistance to enzalutamide. This study was designed to identify inhibitors of AR variants and test its ability to overcome resistance to enzalutamide. The drug screening was conducted using luciferase activity assay to determine the activity of AR-V7 after treatment with the compounds in the Prestwick Chemical Library, which contains about 1,120 FDA-approved drugs. The effects of the identified inhibitors on AR-V7 activity and enzalutamide sensitivity were characterized in CRPC and enzalutamide-resistant prostate cancer cells in vitro and in vivo. Niclosamide, an FDA-approved antihelminthic drug, was identified as a potent AR-V7 inhibitor in prostate cancer cells. Niclosamide significantly downregulated AR-V7 protein expression by protein degradation through a proteasome-dependent pathway. Niclosamide also inhibited AR-V7 transcription activity and reduced the recruitment of AR-V7 to the PSA promoter. Niclosamide inhibited prostate cancer cell growth in vitro and tumor growth in vivo. Furthermore, the combination of niclosamide and enzalutamide resulted in significant inhibition of enzalutamide-resistant tumor growth, suggesting that niclosamide enhances enzalutamide therapy and overcomes enzalutamide resistance in CRPC cells. Niclosamide was identified as a novel inhibitor of AR variants. Our findings offer preclinical validation of niclosamide as a promising inhibitor of AR variants to treat, either alone or in combination with current antiandrogen therapies, patients with advanced prostate cancer, especially those resistant to enzalutamide. ©2014 American

  18. Activation of Notch1 synergizes with multiple pathways in promoting castration-resistant prostate cancer

    PubMed Central

    Stoyanova, Tanya; Riedinger, Mireille; Lin, Shu; Faltermeier, Claire M.; Smith, Bryan A.; Zhang, Kelvin X.; Going, Catherine C.; Goldstein, Andrew S.; Lee, John K.; Drake, Justin M.; Rice, Meghan A.; Hsu, En-Chi; Nowroozizadeh, Behdokht; Castor, Brandon; Orellana, Sandra Y.; Blum, Steven M.; Cheng, Donghui; Pienta, Kenneth J.; Reiter, Robert E.; Pitteri, Sharon J.; Huang, Jiaoti; Witte, Owen N.

    2016-01-01

    Metastatic castration-resistant prostate cancer (CRPC) is the primary cause of prostate cancer-specific mortality. Defining new mechanisms that can predict recurrence and drive lethal CRPC is critical. Here, we demonstrate that localized high-risk prostate cancer and metastatic CRPC, but not benign prostate tissues or low/intermediate-risk prostate cancer, express high levels of nuclear Notch homolog 1, translocation-associated (Notch1) receptor intracellular domain. Chronic activation of Notch1 synergizes with multiple oncogenic pathways altered in early disease to promote the development of prostate adenocarcinoma. These tumors display features of epithelial-to-mesenchymal transition, a cellular state associated with increased tumor aggressiveness. Consistent with its activation in clinical CRPC, tumors driven by Notch1 intracellular domain in combination with multiple pathways altered in prostate cancer are metastatic and resistant to androgen deprivation. Our study provides functional evidence that the Notch1 signaling axis synergizes with alternative pathways in promoting metastatic CRPC and may represent a new therapeutic target for advanced prostate cancer. PMID:27694579

  19. Safety and Efficacy of Docetaxel, Bevacizumab, and Everolimus for Castration-resistant Prostate Cancer (CRPC).

    PubMed

    Gross, Mitchell E; Dorff, Tanya B; Quinn, David I; Diaz, Patricia M; Castellanos, Olga O; Agus, David B

    2017-07-14

    Previous data suggests that co-targeting mammalian target of rapamycin and angiogenic pathways may potentiate effects of cytotoxic chemotherapy. We studied combining mammalian target of rapamycin and vascular endothelial growth factor inhibition with docetaxel in castrate-resistant prostate cancer (CRPC). Eligible patients had progressive, metastatic, chemotherapy-naive CRPC. Docetaxel and bevacizumab were given intravenously day 1 with everolimus orally daily on a 21-day cycle across 3 dose levels (75:15:2.5, 75:15:5, and 65:15:5; docetaxel mg/m(2), mg/kg bevacizumab, and mg everolimus, respectively). Maintenance therapy with bevacizumab/everolimus without docetaxel was allowed after ≥ 6 cycles. Forty-three subjects were treated across all dose levels. Maximal tolerated doses for the combined therapies observed in the phase 1B portion of the trial were: docetaxel 75 mg/m(2), bevacizumab 15 mg/kg, and everolimus 2.5 mg. Maximal prostate-specific antigen decline ≥ 30% and ≥ 50% was achieved in 33 (79%) and 31 (74%) of patients, respectively. Best response by modified Response Evaluation Criteria In Solid Tumors criteria in 25 subjects with measurable disease at baseline included complete or partial response in 20 (80%) patients. The median progression-free and overall survival were 8.9 months (95% confidence interval, 7.4-10.6 months) and 21.9 months (95% confidence interval, 18.4-30.3 months), respectively. Hematologic toxicities were the most common treatment-related grade ≥ 3 adverse events including: febrile neutropenia (12; 28%), lymphopenia (12; 28%), leukocytes (10; 23%), neutrophils (9; 21%), and hemoglobin (2; 5%). Nonhematologic grade ≥ 3 adverse events included: hypertension (8; 19%), fatigue (3; 7%), pneumonia (3; 7%), and mucositis (4; 5%). There was 1 treatment-related death owing to neutropenic fever and pneumonia in a patient treated at dose level 3 despite dose modifications and prophylactic growth factor support. Docetaxel

  20. Predicting survival time for metastatic castration resistant prostate cancer: An iterative imputation approach

    PubMed Central

    Deng, Detian; Du, Yu; Ji, Zhicheng; Rao, Karthik; Wu, Zhenke; Zhu, Yuxin; Coley, R. Yates

    2016-01-01

    In this paper, we present our winning method for survival time prediction in the 2015 Prostate Cancer DREAM Challenge, a recent crowdsourced competition focused on risk and survival time predictions for patients with metastatic castration-resistant prostate cancer (mCRPC). We are interested in using a patient's covariates to predict his or her time until death after initiating standard therapy. We propose an iterative algorithm to multiply impute right-censored survival times and use ensemble learning methods to characterize the dependence of these imputed survival times on possibly many covariates. We show that by iterating over imputation and ensemble learning steps, we guide imputation with patient covariates and, subsequently, optimize the accuracy of survival time prediction. This method is generally applicable to time-to-event prediction problems in the presence of right-censoring. We demonstrate the proposed method's performance with training and validation results from the DREAM Challenge and compare its accuracy with existing methods. PMID:28299176

  1. New Biomarkers for Selecting the Best Therapy Regimens in Metastatic Castration-Resistant Prostate Cancer.

    PubMed

    Heidegger, Isabel; Heidenreich, Axel; Pfister, David

    2017-02-01

    Prostate cancer is the most common cancer in men. In recent years, several new targeted therapeutic agents for the treatment of metastatic castration resistant prostate cancer (mCRPC) have been developed. These include androgen receptor targeting agents, new taxanes, radium-223, and immunotherapies. In this short review, we provide a summary of clinical and preclinical biomarkers for each of these new treatment strategies, also including new markers currently presented in conference papers only. Moreover, we address the role of these biomarkers in clinical routine with the aim to select best-personalized treatment strategies for patients. Finally, we provide a decision tree for selecting the proper therapy for patients with mCRPC according to the discussed biomarkers.

  2. Novel therapeutic approaches for the treatment of castration-resistant prostate cancer.

    PubMed

    Heidegger, Isabel; Massoner, Petra; Eder, Iris E; Pircher, Andreas; Pichler, Renate; Aigner, Friedrich; Bektic, Jasmin; Horninger, Wolfgang; Klocker, Helmut

    2013-11-01

    Prostate cancer is a leading cause of cancer death in men in developed countries. Once the tumor has achieved a castration-refractory metastatic stage, treatment options are limited with the average survival of patients ranging from two to three years only. Recently, new drugs for treatment of castration-resistant prostate cancer (CRPC) have been approved, and others are in an advanced stage of clinical testing. In this review we provide an overview of the new therapeutic agents that arrived in the clinical praxis or are tested in clinical studies and their mode of action including hormone synthesis inhibitors, new androgen receptor blockers, bone targeting and antiangiogenic agents, endothelin receptor antagonists, growth factor inhibitors, novel radiotherapeutics and taxanes, and immunotherapeutic approaches. Results and limitations from clinical studies as well as future needs for improvement of CRPC treatments are critically discussed.

  3. Radium-223 dichloride for metastatic castration-resistant prostate cancer: the urologist's perspective.

    PubMed

    Shore, Neal D

    2015-04-01

    Radium-223 dichloride (radium-223) is an important therapeutic option for the treatment of patients with castration-resistant prostate cancer, symptomatic bone metastases, and no visceral disease. The unique mechanism of action of this first-in-class alpha-emitting radiopharmaceutical underlies its favorable safety profile and low incidence of myelosuppression. In the pivotal phase 3 ALpharadin in SYMptomatic Prostate CAncer Patients study, radium-223 reduced the risk of death by 30% and prolonged time to first symptomatic skeletal event by 5.8 months. This article summarizes current guidelines and clinical studies that led to the approval of radium-223 as an overall survival therapy, and discusses the urologist's perspective on using radium-223 in clinical practice.

  4. [Treatment sequence using newly developed agents for men with castration resistant prostate cancer].

    PubMed

    Fujimoto, Naohiro

    2014-12-01

    Abiraterone acetate(AA), enzalutamide (EZL) and cabazitaxel (CBZ) are becoming available in Japan. Clinical trials demonstrated the benefit of these agents in men with castration resistant prostate cancer (CRPC). However, data on sequence therapy using these agents are very limited. Based on the mechanisms of agents and clinical data, AA and EZL may be indicated in early stage and CBZ may be indicated in late stage of CRPC. Prostate cancer is significantly heterogeneous between individuals and useful biomarkers for deciding the best treatment are unavailable yet. Therefore, it is hard to establish a standard sequence of the treatments. Until clinical trials demonstrate the best treatment sequence, individualized therapy is required for each patient based on patient and disease characteristics.

  5. Management of bone metastases in patients with castration-resistant prostate cancer.

    PubMed

    Cathomas, Richard; Bajory, Zoltan; Bouzid, Mounira; El Ghoneimy, Ahmed; Gillessen, Silke; Goncalves, Frederico; Kacso, Gabriel; Kramer, Gero; Milecki, Piotr; Pacik, Dalibor; Tantawy, Wahid; Lesniewski-Kmak, Krzystof

    2014-01-01

    Bone metastases are a very common problem in prostate cancer. They are associated with considerable morbidity, adversely affect quality of life and frequently lead to advanced bone events (so-called skeletal-related events, SREs); SREs include fractures, spinal cord compression and the requirement for bone surgery or bone radiation. The aim of this paper was to evaluate currently available treatment options in the prevention and management of SREs and bone metastases in men with castration-resistant prostate cancer and to outline the importance of interdisciplinary management strategies. It also discusses the diagnostic workup of osseous metastases and practical considerations for the utilization of bone-targeted therapies in accordance with current guidelines to provide a consensus for special and/or difficult clinical situations.

  6. EZH2 Oncogenic Activity in Castration Resistant Prostate Cancer Cells is Polycomb-Independent

    PubMed Central

    Xu, Kexin; Wu, Zhenhua Jeremy; Groner, Anna C.; He, Housheng Hansen; Cai, Changmeng; Lis, Rosina T.; Wu, Xiaoqiu; Stack, Edward C.; Loda, Massimo; Liu, Tao; Xu, Han; Cato, Laura; Thornton, James E.; Gregory, Richard I.; Morrissey, Colm; Vessella, Robert L.; Montironi, Rodolfo; Magi-Galluzzi, Cristina; Kantoff, Philip W.; Balk, Steven P.; Liu, X. Shirley; Brown, Myles

    2013-01-01

    Epigenetic regulators represent a promising new class of therapeutic targets for cancer. Enhancer of zeste homolog 2 (EZH2), a subunit of Polycomb repressive complex 2 (PRC2), silences gene expression via its histone methyltransferase activity. Here we report that the oncogenic function of EZH2 in castration-resistant prostate cancer (CRPC) is independent of its role as a transcriptional repressor. Instead, it involves the ability of EZH2 to act as a co-activator for critical transcription factors including the androgen receptor (AR). This functional switch is dependent on phosphorylation of EZH2, and requires an intact methyltransferase domain. Hence, targeting the non-PRC2 function of EZH2 may have significant therapeutic efficacy for treating metastatic, hormone-refractory prostate cancer. PMID:23239736

  7. EZH2 oncogenic activity in castration-resistant prostate cancer cells is Polycomb-independent.

    PubMed

    Xu, Kexin; Wu, Zhenhua Jeremy; Groner, Anna C; He, Housheng Hansen; Cai, Changmeng; Lis, Rosina T; Wu, Xiaoqiu; Stack, Edward C; Loda, Massimo; Liu, Tao; Xu, Han; Cato, Laura; Thornton, James E; Gregory, Richard I; Morrissey, Colm; Vessella, Robert L; Montironi, Rodolfo; Magi-Galluzzi, Cristina; Kantoff, Philip W; Balk, Steven P; Liu, X Shirley; Brown, Myles

    2012-12-14

    Epigenetic regulators represent a promising new class of therapeutic targets for cancer. Enhancer of zeste homolog 2 (EZH2), a subunit of Polycomb repressive complex 2 (PRC2), silences gene expression via its histone methyltransferase activity. We found that the oncogenic function of EZH2 in cells of castration-resistant prostate cancer is independent of its role as a transcriptional repressor. Instead, it involves the ability of EZH2 to act as a coactivator for critical transcription factors including the androgen receptor. This functional switch is dependent on phosphorylation of EZH2 and requires an intact methyltransferase domain. Hence, targeting the non-PRC2 function of EZH2 may have therapeutic efficacy for treating metastatic, hormone-refractory prostate cancer.

  8. Cholesterol biosynthesis inhibitor RO 48-8071 suppresses growth of hormone-dependent and castration-resistant prostate cancer cells

    PubMed Central

    Liang, Yayun; Mafuvadze, Benford; Aebi, Johannes D; Hyder, Salman M

    2016-01-01

    Standard treatment for primary prostate cancer includes systemic exposure to chemotherapeutic drugs that target androgen receptor or antihormone therapy (chemical castration); however, drug-resistant cancer cells generally emerge during treatment, limiting the continued use of systemic chemotherapy. Patients are then treated with more toxic standard therapies. Therefore, there is an urgent need for novel and more effective treatments for prostate cancer. The cholesterol biosynthetic pathway is an attractive therapeutic target for treating endocrine-dependent cancers because cholesterol is an essential structural and functional component of cell membranes as well as the metabolic precursor of endogenous steroid hormones. In this study, we have examined the effects of RO 48-8071 (4′-[6-(allylmethylamino)hexyloxy]-4-bromo-2′-fluorobenzophenone fumarate; Roche Pharmaceuticals internal reference: RO0488071) (RO), which is an inhibitor of 2, 3-oxidosqualene cyclase (a key enzyme in the cholesterol biosynthetic pathway), on prostate cancer cells. Exposure of both hormone-dependent and castration-resistant human prostate cancer cells to RO reduced prostate cancer cell viability and induced apoptosis in vitro. RO treatment reduced androgen receptor protein expression in hormone-dependent prostate cancer cells and increased estrogen receptor β (ERβ) protein expression in both hormone-dependent and castration-resistant prostate cancer cell lines. Combining RO with an ERβ agonist increased its ability to reduce castration-resistant prostate cancer cell viability. In addition, RO effectively suppressed the growth of aggressive castration-resistant human prostate cancer cell xenografts in vivo without any signs of toxicity to experimental animals. Importantly, RO did not reduce the viability of normal prostate cells in vitro. Our study is the first to demonstrate that the cholesterol biosynthesis inhibitor RO effectively suppresses growth of human prostate cancer cells

  9. Cholesterol biosynthesis inhibitor RO 48-8071 suppresses growth of hormone-dependent and castration-resistant prostate cancer cells.

    PubMed

    Liang, Yayun; Mafuvadze, Benford; Aebi, Johannes D; Hyder, Salman M

    2016-01-01

    Standard treatment for primary prostate cancer includes systemic exposure to chemotherapeutic drugs that target androgen receptor or antihormone therapy (chemical castration); however, drug-resistant cancer cells generally emerge during treatment, limiting the continued use of systemic chemotherapy. Patients are then treated with more toxic standard therapies. Therefore, there is an urgent need for novel and more effective treatments for prostate cancer. The cholesterol biosynthetic pathway is an attractive therapeutic target for treating endocrine-dependent cancers because cholesterol is an essential structural and functional component of cell membranes as well as the metabolic precursor of endogenous steroid hormones. In this study, we have examined the effects of RO 48-8071 (4'-[6-(allylmethylamino)hexyloxy]-4-bromo-2'-fluorobenzophenone fumarate; Roche Pharmaceuticals internal reference: RO0488071) (RO), which is an inhibitor of 2, 3-oxidosqualene cyclase (a key enzyme in the cholesterol biosynthetic pathway), on prostate cancer cells. Exposure of both hormone-dependent and castration-resistant human prostate cancer cells to RO reduced prostate cancer cell viability and induced apoptosis in vitro. RO treatment reduced androgen receptor protein expression in hormone-dependent prostate cancer cells and increased estrogen receptor β (ERβ) protein expression in both hormone-dependent and castration-resistant prostate cancer cell lines. Combining RO with an ERβ agonist increased its ability to reduce castration-resistant prostate cancer cell viability. In addition, RO effectively suppressed the growth of aggressive castration-resistant human prostate cancer cell xenografts in vivo without any signs of toxicity to experimental animals. Importantly, RO did not reduce the viability of normal prostate cells in vitro. Our study is the first to demonstrate that the cholesterol biosynthesis inhibitor RO effectively suppresses growth of human prostate cancer cells. Our

  10. Castrate-resistant prostate cancer with peritoneal metastases treated with docetaxel-based chemotherapy.

    PubMed

    Rizk, Rita; Danse, Etienne; Aydin, Selda; Tombal, Bertrand; Machiels, Jean-Pascal

    2014-01-01

    To identify the risk factors, characteristics and prognosis of patients treated with docetaxel-based chemotherapy for peritoneal carcinomatosis due to metastatic castrate-resistant prostate cancer (mCRPC). We retrospectively reviewed our series of mCRPC patients with peritoneal metastases treated with docetaxel-based chemotherapy between 2004 and 2010. Six patients were identified from our institutions' internal cancer registry. Three out of these patients had been treated with laparoscopic radical prostatectomy (LRP). In addition to peritoneal metastases, other metastatic sites were mainly visceral. Only 1 patient developed bone metastases. Peritoneal carcinomatosis occurred mainly in patients with a high Gleason (= or >6) score since 5 out of our 6 patients had a Gleason score ≥7. All 6 patients were treated with docetaxel-based chemotherapy when they developed castration resistance. Five patients benefitted from chemotherapy according to their PSA or RECIST responses. Median survival from the start of docetaxel was 24.5 months. Our retrospective analysis suggests that peritoneal carcinomatosis occurs mainly in patients with a high Gleason score. It is also possible that tumor seeding occurs during LRP. Patients with peritoneal carcinomatosis resistant to castration seem to benefit from docetaxel-based chemotherapy. © 2013 S. Karger AG, Basel.

  11. Response to (223)Ra-dichloride in castration-resistant prostate cancer with bone metastasis: A case report.

    PubMed

    Cabrera, Montserrat Estorch; Rey, Pablo Maroto; Carrió, Ignasi; Montes, Alberto; López, Diego Alonso

    2016-08-01

    Painful bone metastases are common in prostate cancer, with current treatments including non-steroidal analgesics and opiates, surgery, external beam radiotherapy and bone-targeting β-emitting radiopharmaceuticals. The α-emitting isotope (223)Ra-dichloride (Ra-223) has been associated with improved overall survival and increased time to first skeletal-related events in patients with castration-resistant prostate cancer (CRPC) presenting with symptomatic bone metastases. The current study reports the case of a 70-year-old male patient, who was diagnosed with prostate cancer in 1999 upon presentation with increased prostate-specific antigen (PSA) levels and painful bone metastases in the context of CRPC. In November 2010, subsequent to undergoing hormonal blockage, the patient was treated with ketoconazole (200 mg/8 h) followed by 10 cycles of docetaxel (75 mg/m(2) every 3 weeks). Following disease progression, the patient received 6 doses of Ra-223 (50 kBq/kg; 1 dose/4 weeks). During this treatment period, an improvement in the patient's symptoms, and levels of bone alkaline phosphatase (BAP) and PSA were noted. Furthermore, Ra-223 was well-tolerated without any relevant bone marrow toxicity. However, 2 months after the administration of the final dose of Ra-223, PSA and BAP levels increased again, and bone pain deteriorated. A bone scan showed stable disease in the previously observed metastatic lesions; however, new lesions simultaneously appeared in different locations, indicating progressive disease.

  12. Characterizing the molecular features of ERG-positive tumors in primary and castration resistant prostate cancer.

    PubMed

    Roudier, Martine P; Winters, Brian R; Coleman, Ilsa; Lam, Hung-Ming; Zhang, Xiaotun; Coleman, Roger; Chéry, Lisly; True, Lawrence D; Higano, Celestia S; Montgomery, Bruce; Lange, Paul H; Snyder, Linda A; Srivastava, Shiv; Corey, Eva; Vessella, Robert L; Nelson, Peter S; Üren, Aykut; Morrissey, Colm

    2016-06-01

    The TMPRSS2-ERG gene fusion is detected in approximately half of primary prostate cancers (PCa) yet the prognostic significance remains unclear. We hypothesized that ERG promotes the expression of common genes in primary PCa and metastatic castration-resistant PCa (CRPC), with the objective of identifying ERG-associated pathways, which may promote the transition from primary PCa to CRPC. We constructed tissue microarrays (TMA) from 127 radical prostatectomy specimens, 20 LuCaP patient-derived xenografts (PDX), and 152 CRPC metastases obtained immediately at time of death. Nuclear ERG was assessed by immunohistochemistry (IHC). To characterize the molecular features of ERG-expressing PCa, a subset of IHC confirmed ERG+ or ERG- specimens including 11 radical prostatectomies, 20 LuCaP PDXs, and 45 CRPC metastases underwent gene expression analysis. Genes were ranked based on expression in primary PCa and CRPC. Common genes of interest were targeted for IHC analysis and expression compared with biochemical recurrence (BCR) status. IHC revealed that 43% of primary PCa, 35% of the LuCaP PDXs, and 18% of the CRPC metastases were ERG+ (12 of 48 patients [25%] had at least one ERG+ metastasis). Based on gene expression data and previous literature, two proteins involved in calcium signaling (NCALD, CACNA1D), a protein involved in inflammation (HLA-DMB), CD3 positive immune cells, and a novel ERG-associated protein, DCLK1 were evaluated in primary PCa and CRPC metastases. In ERG+ primary PCa, a weak association was seen with NCALD and CACNA1D protein expression. HLA-DMB association with ERG was decreased and CD3 cell number association with ERG was changed from positive to negative in CRPC metastases compared to primary PCa. DCLK1 was upregulated at the protein level in unpaired ERG+ primary PCa and CRPC metastases (P = 0.0013 and P < 0.0001, respectively). In primary PCa, ERG status or expression of targeted proteins was not associated with BCR-free survival

  13. Identification and Targeting of Candidate Pre-Existing Lurker Cells that Give Rise to Castration-Resistant Prostate Cancer

    DTIC Science & Technology

    2014-10-01

    propagation. Lgr5+ intestinal stem cells can initiate and maintain murine intestinal adenomas (6, 7). In mouse models of skin cancer, hair follicle bulge...AWARD NUMBER: W81XWH-13-1-0470 TITLE: Identification and Targeting of Candidate Pre... Targeting of Candidate Pre-Existing Lurker Cells that Give Rise to 5a. CONTRACT NUMBER Castration-Resistant Prostate Cancer 5b

  14. Sipuleucel-T: autologous cellular immunotherapy for men with asymptomatic or minimally symptomatic metastatic castrate resistant prostate cancer.

    PubMed

    Sims, Robert B

    2011-01-01

    Sipuleucel T is an autologous cellular immunotherapy designed to stimulate an immune response in men diagnosed with asymptomatic or minimally symptomatic metastatic castrate resistant (hormone refractory) prostate cancer. Sipuleucel T improves overall survival and provides an additional treatment option for this patient population.

  15. Inhibitor SBFI26 suppresses the malignant progression of castration-resistant PC3-M cells by competitively binding to oncogenic FABP5.

    PubMed

    Al-Jameel, Waseem; Gou, Xiaojun; Forootan, Shiva S; Al Fayi, Majed Saad; Rudland, Philip S; Forootan, Farzad S; Zhang, Jiacheng; Cornford, Philip A; Hussain, Syed A; Ke, Youqiang

    2017-05-09

    Castration resistant-prostate cancer is largely impervious to feather hormonal therapy and hence the outlook for patients is grim. Here we use an approach to attach the recently discovered Achilles heel. The experimental treatment established in this study is based on the recent discovery that it is the FABP5-PPARγ-VEGF signalling axis, rather than the androgen receptor pathway, played a dominant role in promoting the malignant progression of castration resistant prostate cancer cells. Treatments have been established in mice by suppressing the biological activity of FABP5 using a chemical inhibitor SBFI26. The inhibitor significantly suppressed the proliferation, migration, invasiveness and colony formation of PC3-M cells in vitro. It also produced a highly significant suppression of both the metastases and the primary tumours developed from cancer cells implanted orthotopically into the prostate glands of the mice. The inhibitor SBFI26 interferes with the FABP5-PPARγ- signalling pathway at the initial stage of the signal transduction by binding competitively to FABP5 to inhibit cellular fatty acid uptake. This avoids the fatty-acid stimulation of PPARγ and prevents it activating the down-stream regulated cancer-promoting genes. This entirely novel experimental approach to treating castration- resistant prostate cancer is completely different from current treatments that are based on androgen-blockade therapy.

  16. EAU-ESTRO-SIOG Guidelines on Prostate Cancer. Part II: Treatment of Relapsing, Metastatic, and Castration-Resistant Prostate Cancer.

    PubMed

    Cornford, Philip; Bellmunt, Joaquim; Bolla, Michel; Briers, Erik; De Santis, Maria; Gross, Tobias; Henry, Ann M; Joniau, Steven; Lam, Thomas B; Mason, Malcolm D; van der Poel, Henk G; van der Kwast, Theo H; Rouvière, Olivier; Wiegel, Thomas; Mottet, Nicolas

    2017-04-01

    be used in men with mCRPC and osseous metastases to prevent skeletal-related complications. The knowledge in the field of advanced and metastatic PCa and CRPC is changing rapidly. The 2016 EAU-ESTRO-SIOG Guidelines on PCa summarise the most recent findings and advice for use in clinical practice. These PCa guidelines are the first endorsed by the European Society for Therapeutic Radiology and Oncology and the International Society of Geriatric Oncology and reflect the multidisciplinary nature of PCa management. A full version is available from the EAU office or online (http://uroweb.org/guideline/prostate-cancer/). In men with a rise in their PSA levels after prior local treatment for prostate cancer only, it is important to balance overtreatment against further progression of the disease since survival and quality of life may never be affected in many of these patients. For patients diagnosed with metastatic castrate-resistant prostate cancer, several new drugs have become available which may provide a clear survival benefit but the optimal choice will have to be made on an individual basis. Copyright © 2016 European Association of Urology. Published by Elsevier B.V. All rights reserved.

  17. Targeting DNA Repair: The Role of PARP Inhibition in the Treatment of Castration-Resistant Prostate Cancer.

    PubMed

    Castro, Elena; Mateo, Joaquin; Olmos, David; de Bono, Johann S

    Several genomic studies have identified DNA repair gene defects in prostate cancer in the last 5 years. The mechanisms by which these DNA repair defects promote carcinogenesis and tumor progression in the prostate have not been fully elucidated, but their presence in at least 20-25% of metastatic castration-resistant prostate cancers (CRPCs) provides an opportunity for a therapeutic strategy that turns a tumor strength into its weakness and may lead to arguably the first molecularly stratified treatment for this disease.Poly(ADP-ribose) polymerase (PARP) inhibitors have been developed as an anticancer synthetic lethal therapeutic strategy for tumors with impaired homologous recombination DNA repair, based on a synthetic lethal effect. Poly(ADP-ribose) polymerase inhibitors have shown to induce significant tumor responses in cancer patients carrying germline BRCA1/2 mutations. Recent evidence from a phase II clinical trial supports further testing of PARP inhibitors for the treatment of metastatic CRPC with either germline or somatic defects in BRCA2, ATM, PALB2, and other DNA repair genes.We review the current evidence of how this strategy is relevant for the treatment of advanced prostate cancers, the available data from trials with PARP inhibitors in metastatic CRPC, and the ongoing studies analyzing combinations of these drugs with other therapies.

  18. Two-step feature selection for predicting survival time of patients with metastatic castrate resistant prostate cancer

    PubMed Central

    Shiga, Motoki

    2016-01-01

    Metastatic castrate resistant prostate cancer (mCRPC) is the major cause of death in prostate cancer patients. Even though some options for treatment of mCRPC have been developed, the most effective therapies remain unclear. Thus finding key patient clinical variables related with mCRPC is an important issue for understanding the disease progression mechanism of mCRPC and clinical decision making for these patients. The Prostate Cancer DREAM Challenge is a crowd-based competition to tackle this essential challenge using new large clinical datasets. This paper proposes an effective procedure for predicting global risks and survival times of these patients, aimed at sub-challenge 1a and 1b of the Prostate Cancer DREAM challenge. The procedure implements a two-step feature selection procedure, which first implements sparse feature selection for numerical clinical variables and statistical hypothesis testing of differences between survival curves caused by categorical clinical variables, and then implements a forward feature selection to narrow the list of informative features. Using Cox’s proportional hazards model with these selected features, this method predicted global risk and survival time of patients using a linear model whose input is a median time computed from the hazard model. The challenge results demonstrated that the proposed procedure outperforms the state of the art model by correctly selecting more informative features on both the global risk prediction and the survival time prediction. PMID:27990267

  19. Current treatments and novel therapeutic targets for castration resistant prostate cancer with bone metastasis

    PubMed Central

    Wei, Juncheng; Wang, Zhilin; Makarov, Danil; Li, Xin

    2013-01-01

    Prostate cancer is a leading cause of cancer death in men in developed countries. While early stage disease can often be cured, many patients eventually develop castration resistant prostate cancer (CRPC). The majority of CRPC patients have bone metastases, which cause significant morbidity and mortality. Although there is no cure for prostate cancer metastatic to bone, several bone-targeted agents have been approved to prevent skeletal-related events (SREs). Among them, bisphosphonates were the first class of drugs investigated for prevention of SREs. Denosumab is a recently approved agent that binds to the receptor activator of nuclear factor-κB ligand (RANKL) as a humanized monoclonal antibody. Both agents target prostate cancer skeletal metastasis through the inhibition of bone resorption. Alpharadin is the first radiopharmaceutical agent that has significant overall survival benefit. It has benefits in pain palliation and SREs as well. Another newly approved drug is Abiraterone acetate, which decreases circulating levels of testosterone by targeting an enzyme expressed in the testis and the adrenal, as well as in prostate cancer tissues. This review outlines the clinical and preclinical data supporting the use of these and new agents in development for CRPC with bone metastasis. PMID:25374898

  20. Radium-223: Insight and Perspectives in Bone-metastatic Castration-resistant Prostate Cancer.

    PubMed

    Buroni, Federica Eleonora; Persico, Marco Giovanni; Pasi, Francesca; Lodola, Lorenzo; Nano, Rosanna; Aprile, Carlo

    2016-11-01

    (223)Ra prolongs overall survival in symptomatic patients affected by multiple bone-metastatic castration-resistant prostatic cancer, without visceral or nodal involvement. However, many questions remain about its mechanisms of action, and its use in clinical practice is still unresolved. First of all, what is the main target of alpha-particle emission, that is, in what way does it influences the tumor microenvironment? When is the best timing in the course of the disease, extending its use to asymptomatic low-volume or even to the micrometastatic phase? What are suitable biomarkers to be employed as prognostic factors and response indicators? Which associations with other drugs and their sequence can offer the best results, and is their effect additive or synergistic? Ultimately, in the current climate of spending review, what is the optimal cost and benefit ratio regarding available treatments? In this review, we tried to answer these questions by analyzing the available scientific literature.

  1. Inhibiting androgen receptor nuclear entry in castration-resistant prostate cancer

    PubMed Central

    Pollock, Julie A.; Wardell, Suzanne E.; Parent, Alexander A.; Stagg, David B.; Ellison, Stephanie J.; Alley, Holly M.; Chao, Christina A.; Lawrence, Scott A.; Stice, James P.; Spasojevic, Ivan; Baker, Jennifer G.; Kim, Sung Hoon; McDonnell, Donald P.; Katzenellenbogen, John A.; Norris, John D.

    2016-01-01

    Clinical resistance to the second-generation antiandrogen enzalutamide in castration resistant prostate cancer (CRPC), despite persistent androgen receptor (AR) activity in tumors, highlights the unmet medical need for next generation antagonists. We have identified and characterized tetra-aryl cyclobutanes (CBs) as a new class of competitive AR antagonists that exhibit a unique mechanism of action. These CBs are structurally distinct from current antiandrogens (hydroxyflutamide, bicalutamide, and enzalutamide), and inhibit AR-mediated gene expression, cell proliferation, and tumor growth in several models of CRPC. Conformational profiling revealed that CBs stabilize an AR conformation resembling an unliganded receptor. Using a variety of techniques, it was determined that the AR:CB complex was not recruited to AR-regulated promoters and, like apo AR, remains sequestered in the cytoplasm bound to heat shock proteins. Thus, we have identified third generation AR antagonists whose unique mechanism of action suggests that they may have therapeutic potential in CRPC. PMID:27501397

  2. Challenges in the sequencing of therapies for the management of metastatic castration-resistant prostate cancer.

    PubMed

    Parente, Phillip; Parnis, Francis; Gurney, Howard

    2014-09-01

    Prior to 2010, docetaxel was the standard option for chemotherapy in men with metastatic castration-resistant prostate cancer (mCRPC). Today, the picture is vastly different: several additional therapies have each demonstrated a survival benefit such that we now have chemotherapy (cabazitaxel), androgen suppressive agents (abiraterone acetate and enzalutamide), a cellular vaccine (sipuleucel-T) and radium-233 (for symptomatic bone metastases). With several other agents in the pipeline for late-stage disease, the future looks promising for mCRPC. As the available data are not able to inform as to the optimum sequencing of therapy, this remains a challenge. This paper draws on insights from published and ongoing clinical studies to provide a practical patient-focused approach to maximize the benefits of the current therapeutic armamentarium. Preliminary sequencing suggestions are made based on clinical trial criteria. But until more data become available, clinical gestalt, experience, cost and individual patient preferences will continue to drive choices.

  3. Radium-223 and metastatic castration-resistant prostate cancer: All that glitters is not gold

    PubMed Central

    Aprile, Carlo; Persico, Marco G; Lodola, Lorenzo; Buroni, Federica E

    2016-01-01

    After being approved by the National Drug Agency in several countries, Radium-223 (Ra-223) is gaining wide acceptance in the treatment of bone metastatic castration resistant prostate cancer. The exact mechanism of action remain unclear: The established model of direct alpha-particle irradiation from the remodelling bone surface, where Ra-223 accumulates, surrounding the tumor foci can explain a lethal effect only on metastatic microdeposits, but not on higher tumor burden. According to the “pre-metastatic niche model”, it is likely that Ra-223 targets several non-tumoral cell types of the tumor microenvironment involved in the complex mechanism of cancer bone homing and colonization. A deeper insight into this hypothetical mechanism will lead to a more accurate dosimetric approach and to find optimal sequencing and/or combination with the other therapeutic options. PMID:27843540

  4. Resistance to abiraterone in castration-resistant prostate cancer: a review of the literature.

    PubMed

    Giacinti, Silvana; Bassanelli, Maria; Aschelter, Anna Maria; Milano, Annalisa; Roberto, Michela; Marchetti, Paolo

    2014-11-01

    Persistent androgen signaling is functionally significant in castration-resistant prostate cancer (CRPC) and it is actually considered a validated therapeutic target. Residual intra-tumoral androgens compensate for the effects of androgen ablation, activating the androgen receptor (AR), AR-mediated gene expression and driving CRPC. The intra-tumoral biosynthesis of androgens takes place in different ways and cytochrome P450 17A1 (CYP17A1) has a crucial role in this context. Abiraterone, a CYP17A1 inhibitor, has shown impressive results in pre- and post-chemotherapy settings, prolonging the survival of patients with CRPC. However, not all patients respond to the treatment and most responders develop resistance, with a widely variable duration of response. Although many hypotheses are emerging, the mechanisms of resistance to abiraterone treatment have not yet been elucidated. The aim of the present review is to describe the main data currently available on resistance to abiraterone.

  5. c-MYC drives histone demethylase PHF8 during neuroendocrine differentiation and in castration-resistant prostate cancer

    PubMed Central

    Liu, Qi; Fazli, Ladan; Tyler, Scott; Nasir, Moman; Dong, Xuesen; Qi, Hank Heng

    2016-01-01

    Epigenetic factors play critical roles in prostate cancer (PCa) development. However, how they contribute to neuroendocrine differentiation (NED) and castration-resistant PCa (CRPC) is not fully understood. Using bioinformatics and biochemical approaches to analyze cell-based models of NED and CRPC, we found a cluster of epigenetic factors whose expression is downregulated during NED and upregulated in CRPC (i.e. follow a Down-Up pattern). Two histone demethylases within this cluster, PHF8 and KDM3A, are post-transcriptionally regulated by c-MYC through miR-22, which targets both PHF8 and KDM3A. We also found that the c-MYC/miR-22/PHF8 axis is downstream of androgen receptor (AR) signaling in CRPC cells. The co-expression of PHF8 with AR in clinical CRPC samples, normal mouse prostate, and adenocarcinomas of the prostate during PCa progression in a transgenic (TRAMP) mouse model supports the connection between PHF8 and AR. Knockdown of PHF8 impedes cell cycle progression in CRPC cells and has more profound effects on their growth than on the parental LNCaP cell line. Furthermore, PHF8 knockdown sensitizes LNCaP-Abl cells to the AR antagonist enzalutamide. Our data reveal novel mechanisms that underlie the regulation of PHF8 and KDM3A during NED and in CRPC, and support the candidacy of PHF8 as a therapeutic target in CRPC. PMID:27689328

  6. c-MYC drives histone demethylase PHF8 during neuroendocrine differentiation and in castration-resistant prostate cancer.

    PubMed

    Maina, Peterson Kariuki; Shao, Peng; Liu, Qi; Fazli, Ladan; Tyler, Scott; Nasir, Moman; Dong, Xuesen; Qi, Hank Heng

    2016-11-15

    Epigenetic factors play critical roles in prostate cancer (PCa) development. However, how they contribute to neuroendocrine differentiation (NED) and castration-resistant PCa (CRPC) is not fully understood. Using bioinformatics and biochemical approaches to analyze cell-based models of NED and CRPC, we found a cluster of epigenetic factors whose expression is downregulated during NED and upregulated in CRPC (i.e. follow a Down-Up pattern). Two histone demethylases within this cluster, PHF8 and KDM3A, are post-transcriptionally regulated by c-MYC through miR-22, which targets both PHF8 and KDM3A. We also found that the c-MYC/miR-22/PHF8 axis is downstream of androgen receptor (AR) signaling in CRPC cells. The co-expression of PHF8 with AR in clinical CRPC samples, normal mouse prostate, and adenocarcinomas of the prostate during PCa progression in a transgenic (TRAMP) mouse model supports the connection between PHF8 and AR. Knockdown of PHF8 impedes cell cycle progression in CRPC cells and has more profound effects on their growth than on the parental LNCaP cell line. Furthermore, PHF8 knockdown sensitizes LNCaP-Abl cells to the AR antagonist enzalutamide. Our data reveal novel mechanisms that underlie the regulation of PHF8 and KDM3A during NED and in CRPC, and support the candidacy of PHF8 as a therapeutic target in CRPC.

  7. Inhibition of Hsp90 Augments Docetaxel Therapy in Castrate Resistant Prostate Cancer

    PubMed Central

    Ku, ShengYu; Lasorsa, Elena; Adelaiye, Remi; Ramakrishnan, Swathi; Ellis, Leigh; Pili, Roberto

    2014-01-01

    First line treatment of patients with castrate resistant prostate cancer (CRPC) primarily involves administration of docetaxel chemotherapy. Unfortunately, resistance to docetaxel therapy is an ultimate occurrence. Alterations in androgen receptor (AR) expression and signaling are associated mechanisms underlying resistance to docetaxel treatment in CRPC. Heat shock protein 90 (Hsp90) is a molecular chaperone, which regulates the activation, maturation and stability of critical signaling proteins involved in prostate cancer, including the AR. This knowledge and recent advances in compound design and development have highlighted Hsp90 as an attractive therapeutic target for the treatment of CRPC. We recently reported the development of a MYC-CaP castrate resistant (MYC-CaP/CR) transplant tumor model, which expresses amplified wild type AR. Within, we report that a second generation Hsp90 inhibitor, NVP-AUY922, inhibits cell growth and significantly induces cell death in MYC-CaP/CR and Pten-CaP/cE2 cell lines. NVP-AUY922 induced proteasome degradation of AR, though interestingly does not require loss of AR protein to inhibit AR transcriptional activity. Further, NVP-AUY922 increased docetaxel toxicity in MYC-CaP/CR and Pten-CaP/cE2 cell lines in vitro. Finally, NVP-AUY922/docetaxel combination therapy in mice bearing MYC-CaP/CR tumors resulted in greater anti-tumor activity compared to single treatment. This study demonstrates that NVP-AUY922 elicits potent activity towards AR signaling and augments chemotherapy response in a mouse model of CRPC, providing rationale for the continued clinical development of Hsp90 inhibitors in clinical trials for treatment of CRPC patients. PMID:25072314

  8. Targeting GPR30 with G-1: a new therapeutic target for castration-resistant prostate cancer

    PubMed Central

    Lam, Hung-Ming; Ouyang, Bin; Chen, Jing; Ying, Jun; Wang, Jiang; Wu, Chin-Lee; Li, Jia; Medvedovic, Mario; Vessella, Robert L.; Ho, Shuk-Mei

    2014-01-01

    Castration-resistant prostate cancer (CRPC) is an advanced-stage prostate cancer (PC) associated with high mortality. We reported that G-1, a selective agonist of G protein-coupled receptor 30 (GPR30), inhibited PC cell growth by inducing G2 cell cycle arrest and arrested PC-3 xenograft growth. However, therapeutic actions of G-1 and their relationships with androgen in vivo are unclear. Using the LNCaP xenograft to model PC growth during androgen-sensitive (AS) versus castration-resistant (CR) phase, we found that G-1 inhibited growth of CR but not AS tumors with no observable toxicity to the host. Substantial necrosis (~65%) accompanied by marked intratumoral infiltration of neutrophils was observed only in CR tumors. Global transcriptome profiling of human genes identified 99 differential expressed genes with “interplay between innate and adaptive immune response” as the top pathway. Quantitative-PCR confirmed upregulation of neutrophil-related chemokines and inflammation-mediated cytokines only in the G-1-treated CR tumors. Expression of murine neutrophil-related cytokines also was elevated in these tumors. GPR30 expression was significantly higher in CR than AS tumors. In cell-based experiments, androgen repressed GPR30 expression, a response reversible by anti-androgen or siRNA-induced androgen receptor silencing. Finally, in clinical specimens, 80% of CRPC metastases (n=123) express a high level of GPR30 whereas only 54% of the primary PCs (n=232) showed high GPR30 expression. Together, these results provide the first evidence that GPR30 is an androgen-repressed target and G-1 mediates the anti-tumor effect via neutrophil infiltration-associated necrosis in CRPC. Additional studies are warranted to firmly establish GPR30 as a therapeutic target in CRPC. PMID:25287069

  9. Using a Novel Transgenic Mouse Model to Study c-Myc Oncogenic Pathway in Castration Resistance and Chemoresistance of Prostate Cancer

    DTIC Science & Technology

    2014-10-01

    model for tumor of epididymis together with prostate tumor. Tumor of epididymis is a rare type of cancer in human, and most of them are benign . The...Oncogenic Pathway in Castration Resistance and Chemoresistance of Prostate Cancer PRINCIPAL INVESTIGATOR: Feng Yang, Ph.D. CONTRACTING...CONTRACT NUMBER Using a Novel Transgenic Mouse Model to Study c-Myc Oncogenic Pathway in Castration Resistance and Chemoresistance of Prostate Cancer

  10. Androgen-independent Molecular Imaging Vectors to Detect Castration-Resistant and Metastatic Prostate Cancer

    PubMed Central

    Jiang, Ziyue Karen; Sato, Makoto; Wei, Liu H.; Kao, Chinghai; Wu, Lily

    2011-01-01

    Prostate specific promoters are frequently employed in gene mediated molecular imaging and therapeutic vectors to diagnose and treat castration resistant prostate cancer (CRPC) that emerges from hormone ablation therapy. Many of the conventional prostate specific promoters rely on the androgen axis to drive gene expression. However, considering the cancer heterogeneity and varying androgen receptor status, we herein evaluated the utility of prostate specific enhancing sequence (PSES), an androgen-independent promoter in CRPC. The PSES is a fused enhancer derived from the prostate specific antigen (PSA) and prostate specific membrane antigen (PSMA) gene regulatory region. We augmented the activity of PSES by the two-step transcriptional amplification (TSTA) system to drive the expression of imaging reporter genes for either bioluminescent or positron emission tomography (PET) imaging. The engineered PSES-TSTA system exhibits greatly elevated transcriptional activity, androgen-independency and strong prostate specificity, verified in cell culture and preclinical animal experimentations. These advantageous features of PSES-TSTA elicit superior gene expression capability for CRPC in comparison to the androgen-dependent PSA promoter driven system. In preclinical settings, we demonstrated robust PET imaging capacity of PSES-TSTA in a castrated prostate xenograft model. Moreover, intravenous administrated PSES-TSTA bioluminescent vector correctly identified tibial bone marrow metastases in 9 out of 9 animals while NaF- and FDG-PET was unable to detect the lesions. Taken together, this study demonstrated that the promising utility of a potent, androgen-independent and prostate cancer-specific expression system in directing gene-based molecular imaging in CRPC even in the context of androgen deprivation therapy. PMID:21933883

  11. Survival prognosis and variable selection: A case study for metastatic castrate resistant prostate cancer patients

    PubMed Central

    Wengel Mogensen, Søren; H. Petersen, Anne; Buchardt, Ann-Sophie; Hansen, Niels Richard

    2016-01-01

    Survival prognosis is challenging, and accurate prediction of individual survival times is often very difficult. Better statistical methodology and more data can help improve the prognostic models, but it is important that methods and data usages are evaluated properly. The Prostate Cancer DREAM Challenge offered a framework for training and blinded validation of prognostic models using a large and rich dataset on patients diagnosed with metastatic castrate resistant prostate cancer. Using the Prostate Cancer DREAM Challenge data we investigated and compared an array of methods combining imputation techniques of missing values for prognostic variables with tree-based and lasso-based variable selection and model fitting methods. The benchmark metric used was integrated AUC (iAUC), and all methods were benchmarked using cross-validation on the training data as well as via the blinded validation. We found that survival forests without prior variable selection achieved the best overall performance (cv-iAUC = 0.70, validation-iACU = 0.78), while a generalized additive model was best among those methods that used explicit prior variable selection (cv-iAUC = 0.69, validation-iACU = 0.76). Our findings largely concurred with previous results in terms of the choice of important prognostic variables, though we did not find the level of prostate specific antigen to have prognostic value given the other variables included in the data. PMID:28105311

  12. Interdisciplinary critique of sipuleucel-T as immunotherapy in castration-resistant prostate cancer.

    PubMed

    Huber, Marie L; Haynes, Laura; Parker, Chris; Iversen, Peter

    2012-02-22

    Sipuleucel-T was approved by the US Food and Drug Administration on April 29, 2010, as an immunotherapy for late-stage prostate cancer. To manufacture sipuleucel-T, mononuclear cells harvested from the patient are incubated with a recombinant prostatic acid phosphatase (PAP) antigen and reinfused. The manufacturer proposes that antigen-presenting cells exogenously activated by PAP induce endogenous T-cells to attack PAP-bearing prostate cancer cells. However, the lack of demonstrable tumor responses has prompted calls for scrutiny of the design of the trials in which sipuleucel-T demonstrated a 4-month survival benefit. Previously unpublished data from the sipuleucel-T trials show worse overall survival in older vs younger patients in the placebo groups, which have not been shown previously to be prognostic for survival in castration-resistant prostate cancer patients receiving chemotherapy. Because two-thirds of the cells harvested from placebo patients, but not from the sipuleucel-T arm, were frozen and not reinfused, a detrimental effect of this large repeated cell loss provides a potential alternative explanation for the survival "benefit." Patient safety depends on adequately addressing this alternative explanation for the trial results.

  13. Determining the frequency of pathogenic germline variants from exome sequencing in patients with castrate-resistant prostate cancer

    PubMed Central

    Hart, Steven N; Ellingson, Marissa S; Schahl, Kim; Vedell, Peter T; Carlson, Rachel E; Sinnwell, Jason P; Barman, Poulami; Sicotte, Hugues; Eckel-Passow, Jeanette E; Wang, Liguo; Kalari, Krishna R; Qin, Rui; Kruisselbrink, Teresa M; Jimenez, Rafael E; Bryce, Alan H; Tan, Winston; Weinshilboum, Richard; Wang, Liewei; Kohli, Manish

    2016-01-01

    Objectives To determine the frequency of pathogenic inherited mutations in 157 select genes from patients with metastatic castrate-resistant prostate cancer (mCRPC). Design Observational. Setting Multisite US-based cohort. Participants Seventy-one adult male patients with histological confirmation of prostate cancer, and had progressive disease while on androgen deprivation therapy. Results Twelve patients (17.4%) showed evidence of carrying pathogenic or likely pathogenic germline variants in the ATM, ATR, BRCA2, FANCL, MSR1, MUTYH, RB1, TSHR and WRN genes. All but one patient opted in to receive clinically actionable results at the time of study initiation. We also found that pathogenic germline BRCA2 variants appear to be enriched in mCRPC compared to familial prostate cancers. Conclusions Pathogenic variants in cancer-susceptibility genes are frequently observed in patients with mCRPC. A substantial proportion of patients with mCRPC or their family members would derive clinical utility from mutation screening. Trial registration number NCT01953640; Results. PMID:27084275

  14. Development of sipuleucel-T: autologous cellular immunotherapy for the treatment of metastatic castrate resistant prostate cancer.

    PubMed

    Sims, Robert B

    2012-06-19

    Sipuleucel-T, the first autologous cellular immunotherapy approved by the United States Food and Drug Administration, is designed to stimulate an immune response to prostate cancer. Sipuleucel-T is manufactured by culturing a patient's peripheral blood mononuclear cells, including autologous antigen presenting cells (APCs), with a recombinant protein comprising a tumor-associated antigen (prostatic acid phosphatase [PAP]) and granulocyte colony-macrophage stimulating factor (GM-CSF). A full course of treatment comprises 3 infusions of sipuleucel-T, given at approximately 2-week intervals. The pattern of APC activation is consistent with priming by the first infusion, and boosting by the second and third infusions. Preclinical and clinical studies have demonstrated evidence of a robust antigen-specific immune response that includes a progressive and persistent increase in antigen-specific cellular and humoral immune responses. Treatment with sipuleucel-T has demonstrated a survival benefit in Phase 3 studies of subjects with metastatic castrate resistant (hormone refractory) prostate cancer (mCRPC). Adverse events with sipuleucel-T were generally mild to moderate and resolved within 2 days. Serious adverse events, autoimmune events, and cerebrovascular events occurred at a similar rate to control subjects. As the first autologous cellular immunotherapy to demonstrate an improvement in overall survival in asymptomatic or minimally symptomatic mCRPC patients, sipuleucel-T represents a new treatment paradigm in oncology.

  15. Cabazitaxel: A novel taxane for metastatic castration-resistant prostate cancer-current implications and future prospects

    PubMed Central

    Abidi, Afroz

    2013-01-01

    Recent advances in the management of prostate cancer have shown considerable development with time and many novel therapeutic agents have been approved over the past years. For patients with metastatic castration-resistant prostate cancer (mCRPC), initially docetaxel was the standard chemotherapy but once they became refractory to docetaxel, no treatment improved survival. This scenario changed in June 2010 when the US Food and Drug Administration (FDA) approved Cabazitaxel as a new therapeutic option for patients with mCRPC resistant to docetaxel. Cabazitaxel, being a novel tubulin-binding taxane with poor affinity for P-glycoprotein, decreases the chances of resistance. It has shown antitumor activity in preclinical, phase I, II and III clinical studies in docetaxel-resistant tumors. This article summarises the background, pharmacodynamic, kinetics and clinical development of cabazitaxel for the treatment of castration-resistant prostate cancer. Future development and rational use of this drug in other tumors is under therapeutic investigation. PMID:24250198

  16. A phase II trial of the Src-kinase inhibitor AZD0530 in patients with advanced castration-resistant prostate cancer: a California Cancer Consortium study.

    PubMed

    Lara, Primo N; Longmate, Jeff; Evans, Christopher P; Quinn, David I; Twardowski, Przemyslaw; Chatta, Gurkamal; Posadas, Edwin; Stadler, Walter; Gandara, David R

    2009-03-01

    Prostate cancer cells undergo neuroendocrine differentiation during androgen deprivation and secrete neuropeptides, hence activating androgen receptor-regulated genes. Src-family protein kinases are involved in neuropeptide-induced prostate cancer growth and migration. A phase II trial of AZD0530, an oral Src-family kinase inhibitor, in patients with advanced castration resistant prostate cancer was conducted. The primary endpoint was prostate cancer-specific antigen (PSA) response rate, defined as a 30% or greater decrease. A two-stage Simon design was used. Eligibility criteria included documentation of castration resistance (including antiandrogen withdrawal), adequate end-organ function, and performance status, and not more than one prior taxane-based chemotherapy regimen. AZD0530 was given at 175 mg orally once daily continuously. Rapid accrual led to 28 patients registering in the first stage. Median age was 67 years. Sixteen patients had performance status (PS) 0, eight patients had PS 1, and four patients had PS 2. Nine patients (32%) had prior docetaxel-based chemotherapy. Five patients had transient PSA reductions not meeting PSA response criteria. Median progression-free survival time was 8 weeks. Treatment was generally well tolerated. AZD0530, a potent oral Src kinase inhibitor, is feasible and tolerable in this pretreated patient population but possessed little clinical efficacy as monotherapy. Strong preclinical evidence warrants further investigation of AZD0530 in earlier-stage prostate cancer or as combination therapy.

  17. Whole Transcriptome Sequencing Reveals Extensive Unspliced mRNA in Metastatic Castration-Resistant Prostate Cancer

    PubMed Central

    Sowalsky, Adam G.; Xia, Zheng; Wang, Liguo; Zhao, Hao; Chen, Shaoyong; Bubley, Glenn J.; Balk, Steven P.; Li, Wei

    2014-01-01

    Men with metastatic prostate cancer (PCa) who are treated with androgen deprivation therapies (ADT) usually relapse within 2–3 years with disease that is termed castration-resistant prostate cancer (CRPC). To identify the mechanism that drives these advanced tumors, paired-end RNA-sequencing (RNA-seq) was performed on a panel of CRPC bone marrow biopsy specimens. From this genome-wide approach, mutations were found in a series of genes with PCa relevance including: AR, NCOR1, KDM3A, KDM4A, CHD1, SETD5, SETD7, INPP4B, RASGRP3, RASA1, TP53BP1 and CDH1, and a novel SND1:BRAF gene fusion. Amongst the most highly-expressed transcripts were ten non-coding RNAs (ncRNAs), including MALAT1 and PABPC1, which are involved in RNA processing. Notably, a high percentage of sequence reads mapped to introns, which were determined to be the result of incomplete splicing at canonical splice junctions. Using quantitative PCR (qPCR) a series of genes (AR, KLK2, KLK3, STEAP2, CPSF6, and CDK19) were confirmed to have a greater proportion of unspliced RNA in CRPC specimens than in normal prostate epithelium, untreated primary PCa, and cultured PCa cells. This inefficient coupling of transcription and mRNA splicing suggests an overall increase in transcription or defect in splicing. PMID:25189356

  18. Antiproliferative activity of novel imidazopyridine derivatives on castration-resistant human prostate cancer cells

    PubMed Central

    Muniyan, Sakthivel; Chou, Yu-Wei; Ingersoll, Matthew A.; Devine, Alexus; Morris, Marisha; Odero-Marah, Valerie A.; Khan, Shafiq A.; Chaney, William G.; Bu, Xiu R.; Lin, Ming-Fong

    2014-01-01

    Metastatic prostate cancer (mPCa) relapses after a short period of androgen deprivation therapy and becomes the castration-resistant prostate cancer (CR PCa); to which the treatment is limited. Hence, it is imperative to identify novel therapeutic agents towards this patient population. In the present study, antiproliferative activities of novel imidazopyridines were compared. Among three derivatives, PHE, AMD and AMN, examined, AMD showed the highest inhibitory activity on LNCaP C-81 cell proliferation, following dose- and time-dependent manner. Additionally, AMD exhibited significant antiproliferative effect against a panel of PCa cells, but not normal prostate epithelial cells. Further, when compared to AMD, its derivative DME showed higher inhibitory activities on PCa cell proliferation, clonogenic potential and in vitro tumorigenicity. The inhibitory activity was apparently in part due to the induction of apoptosis. Mechanistic studies indicate that AMD and DME treatments inhibited both AR and PI3K/Akt signaling. The results suggest that better understanding of inhibitory mechanisms of AMD and DME could help design novel therapeutic agents for improving the treatment of CR PCa. PMID:25050738

  19. Contemporary agents in the management of metastatic castration-resistant prostate cancer

    PubMed Central

    Kapoor, Anil; Wu, Christopher; Shayegan, Bobby; Rybak, Adrian P.

    2016-01-01

    Docetaxel-based chemotherapy has been the standard of care for metastatic castration-resistant prostate cancer (mCRPC) since 2004. Over the past few years, there has been a significant paradigm shift in the treatment landscape of this disease. A deeper understanding of prostate cancer biology, along with the development of novel agents has created hope towards treating chemotherapy-naïve and resistant disease. Following the implementation of docetaxel as the first-line therapy for mCRPC, five novel therapies have demonstrated survival benefit in mCRPC. Cabazitaxel, abiraterone acetate, and enzalutamide are three agents recently approved for the treatment of mCRPC, having shown overall survival benefit in patients previously treated with docetaxel, while both abiraterone acetate and enzalutamide have also shown promise in the pre-docetaxel setting. Sipuleucel-T has shown overall survival benefit in asymptomatic mCRPC, while radium-223 provides survival benefit to patients with mCRPC who are symptomatic from their skeletal metastases in both docetaxel-naïve patients and post-docetaxel patients. Denosumab, an anti-RANKL antibody, has been approved for the prevention of skeletal-related events in patients with prostate cancer bone metastases. This review examines the phase 3 trials supporting the use of theses novel agents in the treatment of mCRPC. While these agents provide incremental increases in patient survival, further study to determine the best choice, combination, and/or sequencing of administration is still necessary. PMID:28096932

  20. Bicalutamide 150 mg as secondary hormonal therapy for castration-resistant prostate cancer.

    PubMed

    Qian, Su-bo; Shen, Hai-bo; Cao, Qi-feng; Zhang, Lin; Chen, Yi-fan; Qi, Jun

    2015-03-01

    This study was aimed to evaluate the effect and tolerability of bicalutamide 150 mg therapy in patients with castration-resistant prostate cancer (CRPC). A total of 48 patients with histologically confirmed prostate cancer were included. They had been treated with continuous maximal androgen blockade therapy, but their serum prostate-specific antigen (PSA) increased after initial hormonal therapy. Patients were given bicalutamide (150 mg per day). Serum PSA testing was performed every 3 months. The response was defined according to PSA decline from baseline: PSA decline ≥85% as complete response, ≥50 % but <85% as partial response, and <50 % as failure. Response duration was defined as the time from PSA response until PSA increased ≥25 % or ≥2 ng/mL from the nadir. The potential predictive factors (Gleason score, clinical stage and serum PSA) were investigated. The time of follow-up was 3-30 months. A PSA decline ≥50% was observed in 37 of 48 patients including 18 ≥ 50% but <85% and 19 ≥ 85% responders. The median response duration was 12 months for partial responders and 20 months for complete responders. Patients with lower Gleason score, lower serum PSA and using flutamide as first-line nonsteroidal antiandrogen achieved more benefits. Moreover, bicalutamide 150 mg therapy was well tolerated. Bicalutamide 150 mg therapy was an appropriate therapeutic method for patients of CRPC, especially for those with lower Gleason score, lower serum PSA and using flutamide as first-line nonsteroidal antiandrogen.

  1. The role of MicroRNA in castration resistant prostate cancer

    PubMed Central

    de Vere White, Ralph; Evans, Christopher P.

    2015-01-01

    Introduction Castration resistant prostate cancer (CRPC) has a historically low median survival rate but recent advances and discoveries in micro RNAs (miRNAs) have opened the potential for new prognostication modalities to enhance therapeutic success. As new chemotherapies and immunotherapies are developed there is an increasing need for precision and stratification of CRPC to allow for optimization and personalization of therapy. Methods A systematic literature review was conducted via electronic database resulting in the selection of forty-two articles based on title, abstract, study format, and content by a consensus of all participating authors. The majority of selected articles were published between 2002 and 2013. In this review, we will discuss the robustness of miRNAs as a biomarker platform, miRNAs associated with prostate cancer, and recent discoveries of miRNA associations with CRPC. Results The associations discovered have been of interest due to the ability to differentiate between CRPC and localized prostate cancer. With evaluation of multiple miRNAs, it is possible to provide a profile in regards to tumor characteristics. Furthermore, actions of miRNAs on CRPC tumor cells have the ability to suppress metastatic phenotypes. Conclusion miRNAs may have a growing role in CRPC prognostication and potentially transform into a therapeutic potential. PMID:24935732

  2. Sipuleucel-T and Androgen Receptor-Directed Therapy for Castration-Resistant Prostate Cancer: A Meta-Analysis

    PubMed Central

    Yi, Renliang; Duan, Peng; Shen, Huanyu; Liu, Qun; Yuan, Chen; Ou, Weilin

    2016-01-01

    New treatments, such as sipuleucel-T and androgen receptor- (AR-) directed therapies (enzalutamide (Enz) and abiraterone acetate (AA)), have emerged and been approved for the management of castration-resistant prostate cancer (CRPC). There are still debates over their efficacy and clinical benefits. This meta-analysis aimed to investigate the efficacy and safety of sipuleucel-T and AR-directed therapies in patients with CRPC. RevMan 5.1 was used for pooled analysis and analysis of publication bias. Seven studies were included in the meta-analysis, with three studies in sipuleucel-T (totally 737 patients, 488 patients in treatment group, and 249 patients in placebo group) and four in AR-directed therapies (totally 5,199 patients, 3,015 patients in treatment group, and 2,184 patients in placebo group). Treatment with sipuleucel-T significantly improved overall survival in patients with CRPC and was not associated with increased risk of adverse event of grade ≥3 (p > 0.05). However, treatment with sipuleucel-T did not improve time-to-progression and reduction of prostate-specific antigen (PSA) level ≥50% was not significantly different from that with placebo. AR-directed therapies significantly improved overall survival in patients with CRPC and improved time-to-progression and reduction of PSA level ≥50%. AR-directed therapies did not increase risk of adverse event of grade ≥3 (p > 0.05). PMID:28058266

  3. Sipuleucel-T and Androgen Receptor-Directed Therapy for Castration-Resistant Prostate Cancer: A Meta-Analysis.

    PubMed

    Yi, Renliang; Chen, Baoxin; Duan, Peng; Zheng, Chanjiao; Shen, Huanyu; Liu, Qun; Yuan, Chen; Ou, Weilin; Zhou, Zhiheng

    2016-01-01

    New treatments, such as sipuleucel-T and androgen receptor- (AR-) directed therapies (enzalutamide (Enz) and abiraterone acetate (AA)), have emerged and been approved for the management of castration-resistant prostate cancer (CRPC). There are still debates over their efficacy and clinical benefits. This meta-analysis aimed to investigate the efficacy and safety of sipuleucel-T and AR-directed therapies in patients with CRPC. RevMan 5.1 was used for pooled analysis and analysis of publication bias. Seven studies were included in the meta-analysis, with three studies in sipuleucel-T (totally 737 patients, 488 patients in treatment group, and 249 patients in placebo group) and four in AR-directed therapies (totally 5,199 patients, 3,015 patients in treatment group, and 2,184 patients in placebo group). Treatment with sipuleucel-T significantly improved overall survival in patients with CRPC and was not associated with increased risk of adverse event of grade ≥3 (p > 0.05). However, treatment with sipuleucel-T did not improve time-to-progression and reduction of prostate-specific antigen (PSA) level ≥50% was not significantly different from that with placebo. AR-directed therapies significantly improved overall survival in patients with CRPC and improved time-to-progression and reduction of PSA level ≥50%. AR-directed therapies did not increase risk of adverse event of grade ≥3 (p > 0.05).

  4. Optimal sequencing of docetaxel and abiraterone in men with metastatic castration-resistant prostate cancer.

    PubMed

    Maughan, Benjamin L; Xhou, Xian C; Suzman, Daniel L; Nadal, Rosa; Bassi, Sunakshi; Schweizer, Michael T; Antonarakis, Emmanuel S

    2015-11-01

    Recent advances have yielded multiple new life-prolonging treatments for men with metastatic castration-resistant prostate cancer (mCRPC) including chemotherapy, next-generation hormonal therapy, immunotherapy, and radiopharmaceutical products. However, the optimal sequencing of these agents to maximize clinical benefit remains unclear. Recent data from the CHAARTED and STAMPEDE studies suggest that early use of docetaxel in men with metastatic hormone-sensitive prostate cancer (mHSPC) significantly improves survival, but whether early compared with delayed use of chemotherapy also provides a survival advantage in mCRPC is unknown. A retrospective analysis of consecutive mCRPC patients treated at Johns Hopkins is reported. Patients included were treated with sequential docetaxel and abiraterone, in either order. The combined progression-free survival (combined PFS: PFS1 + PFS2) of abiraterone-to-docetaxel is compared to the reverse sequence, where PFS1 and PFS2 represent progression-free survival on the first and second agents respectively. Overall survival (OS) from the start of the first therapy to death is compared between groups. Baseline characteristics are reported prior to the start of the first agent in the sequence. Propensity score-weighted multivariable models and Kaplan-Meier analysis are used for evaluation of the primary and secondary outcomes. Fifty-eight patients who began treatment for mCRPC between January 2011 (the year of abiraterone's FDA-approval) and February 2015 were identified: 26 were in the docetaxel-to-abiraterone group and 32 were in the abiraterone-to-docetaxel group. Patients in the abiraterone-to-docetaxel group had more Gleason 8-10 tumors, greater metastatic burden in bone, and higher median PSAs than those in the docetaxel-to-abiraterone group. Propensity score-weighted univariate analyses for combined PFS (HR 0.82; 95%CI 0.50-1.33; P = 0.41) and OS (HR 0.79; 95%CI 0.50-1.25; P = 0.31) do not identify any significant

  5. Estimating high-risk castration resistant prostate cancer (CRPC) using electronic health records.

    PubMed

    Hernandez, Rohini K; Cetin, Karynsa; Pirolli, Melissa; Quigley, Jane; Quach, David; Smith, Paul; Stryker, Scott; Liede, Alexander

    2015-08-01

    Canadian guidelines define castration-resistant prostate cancer (CRPC) at high risk of developing metastases using PSA doubling time (PSADT) < 8 months, whereby men may be offered more frequent bone scans/imaging. We evaluated PSA data from nonmetastatic (M0) prostate cancer patients treated at urology and oncology clinics across the United States (US) to describe the proportion and characteristics of patients who met CRPC and high-risk criteria. We identified M0 prostate cancer patients aged = 18 years receiving androgen deprivation therapy (ADT) in 2011 from electronic health records (EHR), covering 129 urology and 64 oncology practices across the US. We estimated the proportion of prostate cancer patients with evidence of CRPC (consecutive rising PSAs) and subsets that may be at high risk (using several PSA and PSADT cut-points). Among 3121 M0 prostate cancer patients actively treated with ADT, 1188 (38%) had evidence of CRPC. Of these, 712 (60%) qualified as high risk in 2011 based on PSADT < 8 months (equivalent to = 8 months in these data). Men = 65 years were more likely to have evidence of CRPC than younger men, although younger men were more likely to have evidence of high-risk disease. CRPC was more common among men receiving ADT in the oncology setting than the urology setting (48% versus 37%). In this large EHR study with patient-level PSA data, 38% of men with M0 prostate cancer treated with ADT had CRPC. Approximately 60% of M0 CRPC patients may experience a PSADT of < 8 months. These findings require validation in a Canadian patient population.

  6. Inhibition of the Androgen Receptor Amino-Terminal Domain by a Small Molecule as Treatment for Castrate-Resistant Prostate Cancer

    DTIC Science & Technology

    2013-10-01

    Small Molecule as Treatment for Castrate-Resistant Prostate Cancer PRINCIPAL INVESTIGATOR: Stephen R. Plymate CONTRACTING ORGANIZATION...SUBTITLE “Inhibition of the Androgen Receptor Amino-Terminal Domain by a Small Molecule as Treatment for Castrate-Resistant Prostate Cancer” 5a...Sadar MD 2013 EPI small molecules covalently bind intrinsically disordered N-terminal domain of the androgen receptor to inhibit the growth of

  7. Comprehensive Drug Testing of Patient-derived Conditionally Reprogrammed Cells from Castration-resistant Prostate Cancer.

    PubMed

    Saeed, Khalid; Rahkama, Vesa; Eldfors, Samuli; Bychkov, Dmitry; Mpindi, John Patrick; Yadav, Bhagwan; Paavolainen, Lassi; Aittokallio, Tero; Heckman, Caroline; Wennerberg, Krister; Peehl, Donna M; Horvath, Peter; Mirtti, Tuomas; Rannikko, Antti; Kallioniemi, Olli; Östling, Päivi; Af Hällström, Taija M

    2017-03-01

    Technology development to enable the culture of human prostate cancer (PCa) progenitor cells is required for the identification of new, potentially curative therapies for PCa. We established and characterized patient-derived conditionally reprogrammed cells (CRCs) to assess their biological properties and to apply these to test the efficacies of drugs. CRCs were established from seven patient samples with disease ranging from primary PCa to advanced castration-resistant PCa (CRPC). The CRCs were characterized by genomic, transcriptomic, protein expression, and drug profiling. The phenotypic quantification of the CRCs was done based on immunostaining followed by image analysis with Advanced Cell Classifier using Random Forest supervised machine learning. Copy number aberrations (CNAs) were called from whole-exome sequencing and transcriptomics using in-house pipelines. Dose-response measurements were used to generate multiparameter drug sensitivity scores using R-statistical language. We generated six benign CRC cultures which all had an androgen receptor-negative, basal/transit-amplifying phenotype with few CNAs. In three-dimensional cell culture, these cells could re-express the androgen receptor. The CRCs from a CRPC patient (HUB.5) displayed multiple CNAs, many of which were shared with the parental tumor. We carried out high-throughput drug-response studies with 306 emerging and clinical cancer drugs. Using the benign CRCs as controls, we identified the Bcl-2 family inhibitor navitoclax as the most potent cancer-specific drug for the CRCs from a CRPC patient. Other drug efficacies included taxanes, mepacrine, and retinoids. Comprehensive cancer pharmacopeia-wide drug testing of CRCs from a CRPC patient highlighted both known and novel drug sensitivities in PCa, including navitoclax, which is currently being tested in clinical trials of CRPC. We describe an approach to generate patient-derived cancer cells from advanced prostate cancer and apply such cells to

  8. Design and synthesis of an androgen receptor pure antagonist (CH5137291) for the treatment of castration-resistant prostate cancer.

    PubMed

    Yoshino, Hitoshi; Sato, Haruhiko; Shiraishi, Takuya; Tachibana, Kazutaka; Emura, Takashi; Honma, Akie; Ishikura, Nobuyuki; Tsunenari, Toshiaki; Watanabe, Miho; Nishimoto, Ayako; Nakamura, Ryo; Nakagawa, Toshito; Ohta, Masateru; Takata, Noriyuki; Furumoto, Kentaro; Kimura, Kazuya; Kawata, Hiromitsu

    2010-12-01

    A series of 5,5-dimethylthiohydantoin derivatives were synthesized and evaluated for androgen receptor pure antagonistic activities for the treatment of castration-resistant prostate cancer. Since CH4933468, which we reported previously, had a problem with agonist metabolites, novel thiohydantoin derivatives were identified by applying two strategies. One was the replacement of the alkylsulfonamide moiety by a phenylsulfonamide to avoid the production of agonist metabolites. The other was the replacement of the phenyl ring with a pyridine ring to improve in vivo potency and reduce hERG affinity. Pharmacological assays indicated that CH5137291 (17b) was a potent AR pure antagonist which did not produce the agonist metabolite. Moreover, CH5137291 completely inhibited in vivo tumor growth of LNCaP-BC2, a castration-resistant prostate cancer model. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. One-Year Postapproval Clinical Experience with Radium-223 Dichloride in Patients with Metastatic Castrate-Resistant Prostate Cancer

    PubMed Central

    Challa, Sudha; Quinn, David I.; Conti, Peter S.

    2015-01-01

    Abstract Objectives: We report our 1-year postapproval clinical experience with Radium-223 dichloride for treatment of castrate-resistant prostate cancer with bone metastases. Methods: The clinical courses of the first 25 patients treated were reviewed retrospectively. Incidence of hematologic, gastrointestinal, and other adverse events were identified, including those events that led to cessation or delay in treatment. Alterations in bone pain and serum alkaline phosphatase and prostate-specific antigen (PSA) levels were evaluated. Results: Six patients received all 6 scheduled doses of Radium-223 dichloride, 2 completed 5 doses, 6 received 4 doses, 2 completed 3 doses, 6 patients had 2 doses, and 3 patients received one dose, for a total of 91 doses administered. Nine patients discontinued treatment after receiving at least one dose due to progressive disease, 5 required blood transfusions, 5 developed gastrointestinal symptoms, 4 reported worsening bone pain, and 1 developed dermatitis. Downward trends in serum alkaline phosphatase and PSA were seen in 11 and 5 patients, respectively. Conclusions: About one-quarter of cohort completed the entire six-dose treatment. Advancing soft tissue disease was the primary reason for cessation of therapy. The adverse events were mild and manageable. A decline in serum alkaline phosphatase was more common than a decline in PSA. PMID:25746633

  10. One-Year Postapproval Clinical Experience with Radium-223 Dichloride in Patients with Metastatic Castrate-Resistant Prostate Cancer.

    PubMed

    Jadvar, Hossein; Challa, Sudha; Quinn, David I; Conti, Peter S

    2015-06-01

    We report our 1-year postapproval clinical experience with Radium-223 dichloride for treatment of castrate-resistant prostate cancer with bone metastases. The clinical courses of the first 25 patients treated were reviewed retrospectively. Incidence of hematologic, gastrointestinal, and other adverse events were identified, including those events that led to cessation or delay in treatment. Alterations in bone pain and serum alkaline phosphatase and prostate-specific antigen (PSA) levels were evaluated. Six patients received all 6 scheduled doses of Radium-223 dichloride, 2 completed 5 doses, 6 received 4 doses, 2 completed 3 doses, 6 patients had 2 doses, and 3 patients received one dose, for a total of 91 doses administered. Nine patients discontinued treatment after receiving at least one dose due to progressive disease, 5 required blood transfusions, 5 developed gastrointestinal symptoms, 4 reported worsening bone pain, and 1 developed dermatitis. Downward trends in serum alkaline phosphatase and PSA were seen in 11 and 5 patients, respectively. About one-quarter of cohort completed the entire six-dose treatment. Advancing soft tissue disease was the primary reason for cessation of therapy. The adverse events were mild and manageable. A decline in serum alkaline phosphatase was more common than a decline in PSA.

  11. Radium-223 dichloride for the treatment of bone metastatic castration-resistant prostate cancer: an evaluation of its safety.

    PubMed

    Nilsson, Sten

    2015-07-01

    Approximately 10 - 20% of prostate cancer cases ultimately progress to castration-resistant prostate cancer (CRPC), for which there is a poor prognosis and a therapeutic need. Radium-223 dichloride (radium-223 [Xofigo]) is a first-in-class α-emitting radiopharmaceutical shown to significantly prolong overall survival in patients with CRPC with symptomatic bone metastases and no visceral metastases. Current treatment guidelines recommended it in both pre- and post-docetaxel settings. Radium-223 mechanism of action, pharmacokinetics and key efficacy and safety data are reviewed. The evaluation of adverse events reported in the Phase III ALSYMPCA trial is summarized for the overall population and patient subpopulations (prior docetaxel, concomitant external beam radiation therapy and baseline opioid use). An evaluation of how radium-223 is being incorporated into the CRPC treatment paradigm and the implications of its safety profile for future use are provided. The pronounced efficacy and safety profile of radium-223 positions it as a valuable new therapeutic tool in the CRPC armamentarium. Its novel mechanism of action underlies low rates of hematologic adverse events. Radium-223 treatment will become common in the majority of pre-docetaxel symptomatic CRPC cases, as it has proved to be highly efficient with few safety concerns earlier in the course of disease.

  12. LncRNA MALAT1 enhances oncogenic activities of EZH2 in castration-resistant prostate cancer

    PubMed Central

    Wang, Liguo; Zhao, Yu; Sun, Zhifu; Karnes, R. Jeffrey; Zhang, Jun; Huang, Haojie

    2015-01-01

    The Polycomb protein enhancer of zeste homolog 2 (EZH2) is frequently overexpressed in advanced human prostate cancer (PCa), especially in lethal castration-resistant prostate cancer (CRPC). However, the signaling pathways that regulate EZH2 functions in PCa remain incompletely defined. Using EZH2 antibody-based RNA immunoprecipitation-coupled high throughput sequencing (RIP-seq), we demonstrated that EZH2 binds to MALAT1, a long non-coding RNA (lncRNA) that is overexpressed during PCa progression. GST pull-down and RIP assays demonstrated that the 3′ end of MALAT1 interacts with the N-terminal of EZH2. Knockdown of MALAT1 impaired EZH2 recruitment to its target loci and upregulated expression of EZH2 repressed genes. Further studies indicated that MALAT1 plays a vital role in EZH2-enhanced migration and invasion in CRPC cell lines. Meta-analysis and RT-qPCR of patient specimens demonstrated a positive correlation between MALAT1 and EZH2 expression in human CRPC tissues. Finally, we showed that MALAT1 enhances expression of PRC2-independent target genes of EZH2 in CRPC cells in culture and patient-derived xenografts. Together, these data indicate that MALAT1 may be a crucial RNA cofactor of EZH2 and that the EZH2-MALAT1 association may provide a new avenue for development new strategies for treatment of CRPC. PMID:26516927

  13. Niclosamide enhances abiraterone treatment via inhibition of androgen receptor variants in castration resistant prostate cancer

    PubMed Central

    Liu, Chengfei; Armstrong, Cameron; Zhu, Yezi; Lou, Wei; Gao, Allen C.

    2016-01-01

    Considerable evidence from both clinical and experimental studies suggests that androgen receptor variants, particularly androgen receptor variant 7 (AR-V7), are critical in the induction of resistance to enzalutamide and abiraterone. In this study, we investigated the role of AR-V7 in the cross-resistance of enzalutamide and abiraterone and examined if inhibition of AR-V7 can improve abiraterone treatment response. We found that enzalutamide-resistant cells are cross-resistant to abiraterone, and that AR-V7 confers resistance to abiraterone. Knock down of AR-V7 by siRNA in abiraterone resistant CWR22Rv1 and C4-2B MDVR cells restored their sensitivity to abiraterone, indicating that AR-V7 is involved in abiraterone resistance. Abiraterone resistant prostate cancer cells generated by chronic treatment with abiraterone showed enhanced AR-V7 protein expression. Niclosamide, an FDA-approved antihelminthic drug that has been previously identified as a potent inhibitor of AR-V7, re-sensitizes resistant cells to abiraterone treatment in vitro and in vivo. In summary, this preclinical study suggests that overexpression of AR-V7 contributes to resistance to abiraterone, and supports the development of combination of abiraterone with niclosamide as a potential treatment for advanced castration resistant prostate cancer. PMID:27049719

  14. Castration-resistant prostate cancer: locking up the molecular escape routes.

    PubMed

    Attar, Ricardo M; Takimoto, Chris H; Gottardis, Marco M

    2009-05-15

    The understanding of the key role that androgens play on the normal and pathological physiology of the prostate guided the development of different therapies for the treatment of locally advanced or metastatic prostate cancer (PCa). These so-called androgen deprivation therapies include surgical or chemical castration, achieved by the administration of gonadotropin-releasing hormone analogs; inhibition of steroidogenic enzymes; and finally, blocking of the binding of androgens to their receptor (AR) by the use of antiandrogens. Despite an excellent initial response, in approximately 2 to 3 years, most of these patients will succumb to the castration resistant form of the disease. Remarkably, even in the presence of castration levels of circulating androgens, these tumors are still dependent on a functional AR, and several molecular mechanisms have been proposed to explain this phenomenon. These include: (1) gene amplification and increased expression of the AR mRNA and protein, (2) selection of mutations in the AR that confer broader ligand specificity, (3) changes in the ratios or expression between the AR and its coregulators, (4) increased expression of steroidogenic enzymes, and (5) up-regulation of cross-talk signal transduction pathways that can activate the AR in a ligand-independent manner. We will summarize how these molecular hypotheses are being tested in the clinic by the latest therapeutic modalities.

  15. In Silico Discovery of Androgen Receptor Antagonists with Activity in Castration Resistant Prostate Cancer

    PubMed Central

    Shen, Howard C.; Shanmugasundaram, Kumaran; Simon, Nicholas I.; Cai, Changmeng; Wang, Hongyun; Chen, Sen; Rigby, Alan C.

    2012-01-01

    Previously available androgen receptor (AR) antagonists (bicalutamide, flutamide, and nilutamide) have limited activity against AR in prostate cancers that relapse after castration [castration resistant prostate cancer (CRPC)]. However, recent AR competitive antagonists such as MDV3100, generated through chemical modifications to the current AR ligands, appear to have increased activity in CRPC and have novel mechanisms of action. Using pharmacophore models and a refined homology model of the antagonist-liganded AR ligand binding domain, we carried out in silico screens of small molecule libraries and report here on the identification of a series of structurally distinct nonsteroidal small molecule competitive AR antagonists. Despite their unique chemical architectures, compounds representing each of six chemotypes functioned in vitro as pure AR antagonists. Moreover, similarly to MDV3100 and in contrast to previous AR antagonists, these compounds all prevented AR binding to chromatin, consistent with each of the six chemotypes stabilizing a similar AR antagonist conformation. Additional studies with the lead chemotype (chemotype A) showed enhanced AR protein degradation, which was dependent on helix 12 in the AR ligand binding domain. Significantly, chemotype A compounds functioned as AR antagonists in vivo in normal male mice and suppressed AR activity and tumor cell proliferation in human CRPC xenografts. These data indicate that certain ligand-induced structural alterations in the AR ligand binding domain may both impair AR chromatin binding and enhance AR degradation and support continued efforts to develop AR antagonists with unique mechanisms of action and efficacy in CRPC. PMID:23023563

  16. In silico discovery of androgen receptor antagonists with activity in castration resistant prostate cancer.

    PubMed

    Shen, Howard C; Shanmugasundaram, Kumaran; Simon, Nicholas I; Cai, Changmeng; Wang, Hongyun; Chen, Sen; Balk, Steven P; Rigby, Alan C

    2012-11-01

    Previously available androgen receptor (AR) antagonists (bicalutamide, flutamide, and nilutamide) have limited activity against AR in prostate cancers that relapse after castration [castration resistant prostate cancer (CRPC)]. However, recent AR competitive antagonists such as MDV3100, generated through chemical modifications to the current AR ligands, appear to have increased activity in CRPC and have novel mechanisms of action. Using pharmacophore models and a refined homology model of the antagonist-liganded AR ligand binding domain, we carried out in silico screens of small molecule libraries and report here on the identification of a series of structurally distinct nonsteroidal small molecule competitive AR antagonists. Despite their unique chemical architectures, compounds representing each of six chemotypes functioned in vitro as pure AR antagonists. Moreover, similarly to MDV3100 and in contrast to previous AR antagonists, these compounds all prevented AR binding to chromatin, consistent with each of the six chemotypes stabilizing a similar AR antagonist conformation. Additional studies with the lead chemotype (chemotype A) showed enhanced AR protein degradation, which was dependent on helix 12 in the AR ligand binding domain. Significantly, chemotype A compounds functioned as AR antagonists in vivo in normal male mice and suppressed AR activity and tumor cell proliferation in human CRPC xenografts. These data indicate that certain ligand-induced structural alterations in the AR ligand binding domain may both impair AR chromatin binding and enhance AR degradation and support continued efforts to develop AR antagonists with unique mechanisms of action and efficacy in CRPC.

  17. AKR1C3 as a target in castrate resistant prostate cancer.

    PubMed

    Adeniji, Adegoke O; Chen, Mo; Penning, Trevor M

    2013-09-01

    Aberrant androgen receptor (AR) activation is the major driver of castrate resistant prostate cancer (CRPC). CRPC is ultimately fatal and more therapeutic agents are needed to treat this disease. Compounds that target the androgen axis by inhibiting androgen biosynthesis and or AR signaling are potential candidates for use in CRPC treatment and are currently being pursued aggressively. Aldo-keto reductase 1C3 (AKR1C3) plays a pivotal role in androgen biosynthesis within the prostate. It catalyzes the 17-ketoreduction of weak androgen precursors to give testosterone and 5α-dihydrotestosterone. AKR1C3 expression and activity has been implicated in the development of CRPC, making it a rational target. Selective inhibition of AKR1C3 will be important, however, due to the presence of closely related isoforms, AKR1C1 and AKR1C2 that are also involved in androgen inactivation. We examine the evidence that supports the vital role of AKR1C3 in CRPC and recent developments in the discovery of potent and selective AKR1C3 inhibitors. This article is part of a Special Issue entitled 'CSR 2013'.

  18. Nursing management of patients with castration-resistant prostate cancer undergoing radium-223 dichloride treatment.

    PubMed

    Delacruz, Anthony; Arauz, Gabrielle; Curley, Tracy; Lindo, Amabella; Jensen, Trine

    2015-04-01

    Radium-223 dichloride, or radium-223, is a first-in-class alpha emitter that selectively targets bone metastases with high-energy, short-range alpha particles and is approved for the treatment of patients with castration-resistant prostate cancer (CRPC), symptomatic bone metastases, and no known visceral metastatic disease. Nurses are essential in educating patients about radium-223. This article provides oncology nurses with information from the randomized phase III Alpharadin in Symptomatic Prostate Cancer (ALSYMPCA) trial, as well as important handling, administration, and safety details unique to radium-223. Data from the ALSYMPCA trial and related published information on radium-223 were reviewed. Radium-223 is the only alpha-emitting radiopharmaceutical that has been shown to improve overall survival in patients with CRPC, as demonstrated in the ALSYMPCA trial. In addition, radium-223 delays time to first symptomatic skeletal event, and it is well tolerated with a low incidence of myelosuppression and gastrointestinal adverse events. Delivered on an outpatient basis, radium-223 requires universal precautions for handling and administration. Because of the potential for additive myelosuppression, the concomitant use of radium-223 with chemotherapy, other systemic radioisotopes, or hemibody external radiation therapy is not recommended.

  19. Radium-223 dichloride for the treatment of castration-resistant prostate cancer with symptomatic bone metastases.

    PubMed

    Vogelzang, Nicholas J

    2017-08-01

    Castration-resistant prostate cancer (CRPC) is associated with the development of bone metastases, increased mortality, and a reduction in the patient's quality of life (QOL). The management of metastatic CRPC (mCRPC) has rapidly evolved over the past decade, with a number of available therapeutic agents improving overall survival. Radium-223 dichloride (radium-223), the first targeted alpha therapy, improves survival accompanied by QOL benefits with a favorable safety profile. It is approved in over 40 countries for the treatment of patients with CRPC with symptomatic bone metastases and no known visceral metastatic disease. Areas covered: The current management of CRPC in men with bone metastases, and in particular the role of radium-223 in this setting, is reviewed and discussed. A search of bibliographic databases for peer-reviewed literature and major meetings was conducted. Expert commentary: In treating patients with mCRPC, the best sequencing and/or combination of radium-223 with other agents has yet to be fully elucidated. The role of radium-223 in treating patients with hormone-sensitive metastatic prostate cancer who are candidates for chemotherapy should also be investigated in well-designed trials. The ability to tailor radium-223 therapy to both the clinical and genetic profiles of CRPC patients would be a promising development.

  20. Radium-223 for the treatment of castration-resistant prostate cancer

    PubMed Central

    El-Amm, Joelle; Aragon-Ching, Jeanny B

    2015-01-01

    The vast majority of patients with metastatic castration-resistant prostate cancer (mCRPC) develop bone metastases. Bone metastases are a source of significant morbidity and affect quality of life in these patients. Several bone-targeting agents are approved for the treatment of bone metastases in prostate cancer, including bisphosphonates, denosumab, and radiopharmaceuticals. Radium-223 is a novel first-in-class alpha-emitting radiopharmaceutical that has been approved for treatment of patients with mCRPC with bone metastases. Radium-223 delivers cytotoxic radiation to the sites of bone metastases and offers the advantage of minimal myelosuppression. The landmark Phase III ALSYMPCA trial demonstrated that, in addition to providing bone-related palliation, radium-223 can also prolong overall survival in patients with mCRPC with bone metastases in the absence of visceral metastases and in the absence of lymphadenopathy greater than 3 cm. Ongoing trials will further elucidate its use in sequence or combination with other available therapies for mCRPC. PMID:26056474

  1. Inhibition of the hexosamine biosynthetic pathway promotes castration-resistant prostate cancer

    PubMed Central

    Kaushik, Akash K.; Shojaie, Ali; Panzitt, Katrin; Sonavane, Rajni; Venghatakrishnan, Harene; Manikkam, Mohan; Zaslavsky, Alexander; Putluri, Vasanta; Vasu, Vihas T.; Zhang, Yiqing; Khan, Ayesha S.; Lloyd, Stacy; Szafran, Adam T.; Dasgupta, Subhamoy; Bader, David A.; Stossi, Fabio; Li, Hangwen; Samanta, Susmita; Cao, Xuhong; Tsouko, Efrosini; Huang, Shixia; Frigo, Daniel E.; Chan, Lawrence; Edwards, Dean P.; Kaipparettu, Benny A.; Mitsiades, Nicholas; Weigel, Nancy L.; Mancini, Michael; McGuire, Sean E.; Mehra, Rohit; Ittmann, Michael M.; Chinnaiyan, Arul M.; Putluri, Nagireddy; Palapattu, Ganesh S.; Michailidis, George; Sreekumar, Arun

    2016-01-01

    The precise molecular alterations driving castration-resistant prostate cancer (CRPC) are not clearly understood. Using a novel network-based integrative approach, here, we show distinct alterations in the hexosamine biosynthetic pathway (HBP) to be critical for CRPC. Expression of HBP enzyme glucosamine-phosphate N-acetyltransferase 1 (GNPNAT1) is found to be significantly decreased in CRPC compared with localized prostate cancer (PCa). Genetic loss-of-function of GNPNAT1 in CRPC-like cells increases proliferation and aggressiveness, in vitro and in vivo. This is mediated by either activation of the PI3K-AKT pathway in cells expressing full-length androgen receptor (AR) or by specific protein 1 (SP1)-regulated expression of carbohydrate response element-binding protein (ChREBP) in cells containing AR-V7 variant. Strikingly, addition of the HBP metabolite UDP-N-acetylglucosamine (UDP-GlcNAc) to CRPC-like cells significantly decreases cell proliferation, both in-vitro and in animal studies, while also demonstrates additive efficacy when combined with enzalutamide in-vitro. These observations demonstrate the therapeutic value of targeting HBP in CRPC. PMID:27194471

  2. Targeting Plk1 to Enhance Efficacy of Olaparib in Castration-Resistant Prostate Cancer.

    PubMed

    Li, Jie; Wang, Ruixin; Kong, Yifan; Broman, Meaghan M; Carlock, Colin; Chen, Long; Li, Zhiguo; Farah, Elia; Ratliff, Timothy L; Liu, Xiaoqi

    2017-03-01

    Olaparib is an FDA-approved PARP inhibitor (PARPi) that has shown promise as a synthetic lethal treatment approach for BRCA-mutant castration-resistant prostate cancer (CRPC) in clinical use. However, emerging data have also shown that even BRCA-mutant cells may be resistant to PARPi. The mechanistic basis for these drug resistances is poorly understood. Polo-like kinase 1 (Plk1), a critical regulator of many cell-cycle events, is significantly elevated upon castration of mice carrying xenograft prostate tumors. Herein, by combination with Plk1 inhibitor BI2536, we show a robust sensitization of olaparib in 22RV1, a BRCA1-deficient CRPC cell line, as well as in CRPC xenograft tumors. Mechanistically, monotherapy with olaparib results in an override of the G1-S checkpoint, leading to high expression of Plk1, which attenuates olaparib's overall efficacy. In BRCA1 wild-type C4-2 cells, Plk1 inhibition also significantly increases the efficacy of olaparib in the presence of p53 inhibitor. Collectively, our findings not only implicate the critical role of Plk1 in PARPi resistance in BRCA-mutant CRPC cells, but also shed new light on the treatment of non-BRCA-mutant patient subgroups who might also respond favorably to PARPi. Mol Cancer Ther; 16(3); 469-79. ©2017 AACR. ©2017 American Association for Cancer Research.

  3. Hydrazinobenzoylcurcumin inhibits androgen receptor activity and growth of castration-resistant prostate cancer in mice

    PubMed Central

    Wu, Min; Kim, Sahn-Ho; Datta, Indrani; Levin, Albert; Dyson, Gregory; Li, Jing; Kaypee, Stephanie; Swamy, M. Mahadeva; Gupta, Nilesh; Kwon, Ho Jeong; Menon, Mani; Kundu, Tapas K.; Reddy, G. Prem-Veer

    2015-01-01

    There is a critical need for therapeutic agents that can target the amino-terminal domain (NTD) of androgen receptor (AR) for the treatment of castration-resistant prostate cancer (CRPC). Calmodulin (CaM) binds to the AR NTD and regulates AR activity. We discovered that Hydrazinobenzoylcurcumin (HBC), which binds exclusively to CaM, inhibited AR activity. HBC abrogated AR interaction with CaM, suppressed phosphorylation of AR Serine81, and blocked the binding of AR to androgen-response elements. RNA-Seq analysis identified 57 androgen-regulated genes whose expression was significantly (p ≤ 0.002) altered in HBC treated cells as compared to controls. Oncomine analysis revealed that genes repressed by HBC are those that are usually overexpressed in prostate cancer (PCa) and genes stimulated by HBC are those that are often down-regulated in PCa, suggesting a reversing effect of HBC on androgen-regulated gene expression associated with PCa. Ingenuity Pathway Analysis revealed a role of HBC affected genes in cellular functions associated with proliferation and survival. HBC was readily absorbed into the systemic circulation and inhibited the growth of xenografted CRPC tumors in nude mice. These observations demonstrate that HBC inhibits AR activity by targeting the AR NTD and suggest potential usefulness of HBC for effective treatment of CRPC. PMID:25704883

  4. Niclosamide enhances abiraterone treatment via inhibition of androgen receptor variants in castration resistant prostate cancer.

    PubMed

    Liu, Chengfei; Armstrong, Cameron; Zhu, Yezi; Lou, Wei; Gao, Allen C

    2016-05-31

    Considerable evidence from both clinical and experimental studies suggests that androgen receptor variants, particularly androgen receptor variant 7 (AR-V7), are critical in the induction of resistance to enzalutamide and abiraterone. In this study, we investigated the role of AR-V7 in the cross-resistance of enzalutamide and abiraterone and examined if inhibition of AR-V7 can improve abiraterone treatment response. We found that enzalutamide-resistant cells are cross-resistant to abiraterone, and that AR-V7 confers resistance to abiraterone. Knock down of AR-V7 by siRNA in abiraterone resistant CWR22Rv1 and C4-2B MDVR cells restored their sensitivity to abiraterone, indicating that AR-V7 is involved in abiraterone resistance. Abiraterone resistant prostate cancer cells generated by chronic treatment with abiraterone showed enhanced AR-V7 protein expression. Niclosamide, an FDA-approved antihelminthic drug that has been previously identified as a potent inhibitor of AR-V7, re-sensitizes resistant cells to abiraterone treatment in vitro and in vivo. In summary, this preclinical study suggests that overexpression of AR-V7 contributes to resistance to abiraterone, and supports the development of combination of abiraterone with niclosamide as a potential treatment for advanced castration resistant prostate cancer.

  5. Mechanistic Support for Combined MET and AR Blockade in Castration-Resistant Prostate Cancer.

    PubMed

    Qiao, Yuanyuan; Feng, Felix Y; Wang, Yugang; Cao, Xuhong; Han, Sumin; Wilder-Romans, Kari; Navone, Nora M; Logothetis, Christopher; Taichman, Russell S; Keller, Evan T; Palapattu, Ganesh S; Alva, Ajjai S; Smith, David C; Tomlins, Scott A; Chinnaiyan, Arul M; Morgan, Todd M

    2016-01-01

    A recent phase III trial of the MET kinase inhibitor cabozantinib in men with castration-resistant prostate cancer (CRPC) failed to meet its primary survival end point; however, most men with CRPC have intact androgen receptor (AR) signaling. As previous work supports negative regulation of MET by AR signaling, we hypothesized that intact AR signaling may have limited the efficacy of cabozantinib in some of these patients. To assess the role of AR signaling on MET inhibition, we first performed an in silico analysis of human CRPC tissue samples stratified by AR signaling status ((+) or (-)), which identified MET expression as markedly increased in AR(-) samples. In vitro, AR signaling inhibition in AR(+) CRPC models increased MET expression and resulted in susceptibility to ligand (HGF) activation. Likewise, MET inhibition was only effective in blocking cancer phenotypes in cells with MET overexpression. Using multiple AR(+) CRPC in vitro and in vivo models, we showed that combined cabozantinib and enzalutamide (AR antagonist) treatment was more efficacious than either inhibitor alone. These data provide a compelling rationale to combine AR and MET inhibition in CRPC and may explain the negative results of the phase III cabozantinib study in CRPC. Similarly, the expression of MET in AR(-) disease, whether due to AR inhibition or loss of AR signaling, suggests potential utility for MET inhibition in select patients with AR therapy resistance and in AR(-) prostate cancer.

  6. Development of Small Molecule Activators of Protein Phosphotase 2A (SMAPs) for the Treatment of Castration Resistant Prostate Cancer

    DTIC Science & Technology

    2016-10-01

    1 AWARD NUMBER: W81XWH-15-1-0598 TITLE: Development of Small Molecule Activators of Protein Phosphotase 2A (SMAPs) for the Treatment of...Small Molecule Activators of Protein Phosphotase 2A (SMAPs) for the Treatment of Castration-Resistant Prostate Cancer 5a. CONTRACT NUMBER 5b. GRANT...SUPPLEMENTARY NOTES 14. ABSTRACT Subject: Protein phosphatase 2A (PP2A) is among the most abundant serine threonine phosphatases in mammalian cells, a bona

  7. Marine compound rhizochalinin shows high in vitro and in vivo efficacy in castration resistant prostate cancer

    PubMed Central

    Alsdorf, Winfried H.; Hauschild, Jessica; Lange, Tobias; Venz, Simone; Bauer, Christiane K.; Bähring, Robert; Amann, Kerstin; Mandanchi, Ramin; Schumacher, Udo; Schröder-Schwarz, Jennifer; Makarieva, Tatyana N.; Guzii, Alla G.; Tabakmakher, Kseniya M.; Fedorov, Sergey N.; Shubina, Larisa K.; Kasheverov, Igor E.; Ehmke, Heimo; Steuber, Thomas; Stonik, Valentin A.; Bokemeyer, Carsten; Honecker, Friedemann; von Amsberg, Gunhild

    2016-01-01

    Development of drug resistance is an inevitable phenomenon in castration-resistant prostate cancer (CRPC) cells requiring novel therapeutic approaches. In this study, efficacy and toxicity of Rhizochalinin (Rhiz) – a novel sphingolipid-like marine compound – was evaluated in prostate cancer models, resistant to currently approved standard therapies. In vitro activity and mechanism of action of Rhiz were examined in the human prostate cancer cell lines PC-3, DU145, LNCaP, 22Rv1, and VCaP. Rhiz significantly reduced cell viability at low micromolar concentrations showing most pronounced effects in enzalutamide and abiraterone resistant AR-V7 positive cells. Caspase-dependent apoptosis, inhibition of pro-survival autophagy, downregulation of AR-V7, PSA and IGF-1 expression as well as inhibition of voltage-gated potassium channels were identified as mechanisms of action. Remarkably, Rhiz re-sensitized AR-V7 positive cells to enzalutamide and increased efficacy of taxanes. In vivo activity and toxicity were evaluated in PC-3 and 22Rv1 NOD SCID mouse xenograft models using i.p. administration. Rhiz significantly reduced growth of PC-3 and 22Rv1 tumor xenografts by 27.0% (p = 0.0156) and 46.8% (p = 0.047) compared with controls with an increased fraction of tumor cells showing apoptosis secondary to Rhiz exposure. In line with the in vitro data, Rhiz was most active in AR-V7 positive xenografts in vivo. In animals, no severe side effects were observed. In conclusion, Rhiz is a promising novel marine-derived compound characterized by a unique combination of anticancer properties. Its further clinical development is of high impact for patients suffering from drug resistant prostate cancer especially those harboring AR-V7 mediated resistance to enzalutamide and abiraterone. PMID:27626485

  8. The cistrome and gene signature of androgen receptor splice variants in castration-resistant prostate cancer cells

    PubMed Central

    Lu, Ji; Lonergan, Peter E.; Nacusi, Lucas P.; Wang, Liguo; Schmidt, Lucy J.; Sun, Zhifu; Van der Steen, Travis; Boorjian, Stephen A.; Kosari, Farhad; Vasmatzis, George; Klee, George G.; Balk, Steven P.; Huang, Haojie; Wang, Chunxi; Tindall, Donald J.

    2015-01-01

    Purpose Spliced variant forms of androgen receptor (AR-Vs) have been identified recently in castration-resistant prostate cancer (CRPC) cell lines and clinical samples. We identified the cistrome and gene signature of AR-Vs in CRPC cell lines and determined the clinical significance of AR-Vs regulated genes. Materials and Methods The CRPC cell line 22Rv1, which expresses both full length androgen receptor (AR-FL) and AR-Vs endogenously, was used as the research model. We established 22Rv1-ARFL−/ARVs+ and 22Rv1- ARFL−/ARVs− through RNA interference. ChIP-seq and microarray techniques were used to identify cistrome and gene expression profiles of AR-Vs in the absence of androgen. Results AR-Vs binding sites were identified in 22Rv1-ARFL−/ARVs+. A set of genes was found to be regulated uniquely by AR-Vs, but not by full-length AR in the absence of androgen. Integrated analysis revealed that some genes are modulated by AR-Vs directly. Unsupervised clustering analysis showed that the AR-Vs gene signature can differentiate not only benign from malignant prostate tissue, but also localized prostate cancer from metastatic CRPC specimens. Some genes that were modulated uniquely by AR-Vs also correlated with histological grade and biochemical failure. Conclusions We conclude that AR-Vs can bind to DNA independently of full-length AR in the absence of androgen and modulate a unique set of genes that is not regulated by AR-FL. The AR-Vs gene signature correlates with disease progression, and distinguishes between primary cancer and CRPC specimens, as well as benign and malignant prostate specimens. PMID:25132238

  9. Race does not predict the development of metastases in men with nonmetastatic castration-resistant prostate cancer.

    PubMed

    Whitney, Colette A; Howard, Lauren E; Amling, Christopher L; Aronson, William J; Cooperberg, Matthew R; Kane, Christopher J; Terris, Martha K; Freedland, Stephen J

    2016-12-15

    Although race is associated with prostate cancer progression in early stage disease, once men have advanced disease, it is unclear whether race continues to predict a poor outcome. The authors hypothesized that, in an equal-access setting among patients with castration-resistant prostate cancer (CRPC) and no known metastases (M0/Mx), black men would receive imaging tests at similar rates as nonblack men (ie, there would be an equal opportunity to detect metastases) but would have a higher risk of metastatic disease. In total, 837 men who were diagnosed with M0/Mx CRPC during 2000 through 2014 from 5 Veterans Affairs hospitals in the SEARCH (Shared Equal Access Regional Cancer Hospital) database were analyzed. Data on all imaging tests after CRPC diagnosis were collected, including date, type, and outcome. Multivariable Cox models were used to test associations between race and the time to first metastasis, first bone metastasis, first bone scan, second bone scan among men who had a negative first bone scan, and overall survival. Black men (n = 306) were equally as likely as nonblack men (n = 531) to receive a first and second bone scan after a diagnosis of CRPC. There were no significant differences in the risk of developing any metastases, bone metastases, time to bone scans, or overall survival between black men and nonblack men (all P > .2). The lack of racial differences in the development of metastases and scanning practices observed in this study suggests that, once men have a diagnosis of M0/Mx CRPC, race may not be a prognostic factor. Efforts to understand prostate cancer racial disparities may derive greater benefit by focusing on the risk of developing prostate cancer and on the outcomes of men who have early stage disease. Cancer 2016;122:3848-3855. © 2016 American Cancer Society. © 2016 American Cancer Society.

  10. Comparative analyses of chromosome alterations in soft-tissue metastases within and across patients with castration-resistant prostate cancer

    PubMed Central

    Holcomb, Ilona N.; Young, Janet M.; Coleman, Ilsa M.; Salari, Keyan; Grove, Douglas I.; Hsu, Li; True, Lawrence D.; Roudier, Martine P.; Morrissey, Colm M.; Higano, Celestia S.; Nelson, Peter S.; Vessella, Robert L.; Trask, Barbara J.

    2009-01-01

    Androgen deprivation is the mainstay of therapy for progressive prostate cancer. Despite initial and dramatic tumor inhibition, most men eventually fail therapy and die of metastatic castration-resistant (CR) disease. Here, we characterize the profound degree of genomic alteration found in CR tumors using array CGH, gene expression arrays, and FISH. By cluster analysis, we show that the similarity of the genomic profiles from primary and metastatic tumors is driven by the patient. Using data adjusted for this similarity, we identify numerous high-frequency alterations in the CR tumors, such as 8p loss and chromosome 7 and 8q gain. By integrating array CGH and expression array data, we reveal genes whose correlated values suggest they are relevant to prostate cancer biology. We find alterations that are significantly associated with the metastases of specific organ sites, and others with CR tumors versus the tumors of patients with localized prostate cancer not treated with androgen deprivation. Within the high-frequency sites of loss in CR metastases, we find an over-representation of genes involved in cellular lipid metabolism, including PTEN. Finally, using FISH we verify the presence of a gene fusion between TMPRSS2 and ERG suggested by chromosome-21 deletions detected by array CGH. We find the fusion in 54% of our CR tumors, and 81% of the fusion-positive tumors contain cells with multiple copies of the fusion. Our investigation lays the foundation for a better understanding of and possible therapeutic targets for CR disease, the poorly responsive and final stage of prostate cancer. PMID:19773449

  11. CX4945 suppresses the growth of castration-resistant prostate cancer cells by reducing AR-V7 expression.

    PubMed

    Deng, Chuangzhong; Chen, Jieping; Guo, Shengjie; Wang, Yanjun; Zhou, Qianghua; Li, Zaishang; Yang, Xingping; Yu, Xingsu; Zhang, Zhenfeng; Zhou, Fangjian; Han, Hui; Yao, Kai

    2017-08-01

    The aberrant expression of casein kinase 2 (CK2) has been reported to be involved in the tumorigenesis and progression of prostate cancer. The inhibition of CK2 activity represses androgen-dependent prostate cancer cells by attenuating the androgen receptor (AR) signaling pathway. In this study, we examined the effect of CK2 inhibition in castration-resistant prostate cancer (CRPC) cells, in which AR variants (ARVs) play a predominant role. A newly synthetic CK2 selective inhibitor CX4945 was utilized to study the effect of CK2 inhibition in CRPC cells by CCK8 assay and colony formation assay. Protein and mRNA levels of full-length AR (AR-FL) and AR-V7 were determined by qPCR and western blot, respectively. The nuclear translocation of p50 and p65 was assessed to reflect the activity of the NF-κB pathway. CX4945 reduced the proliferation of CRPC cells in a dose-dependent and time-dependent manner. AR-V7 rather than AR-FL was downregulated by CX4945 in both the mRNA and protein level. Furthermore, CX4945 could restore the sensitivity of CRPC cells to bicalutamide. The analysis of possible mechanisms demonstrated that the inhibition of CK2 diminished the phosphorylation of p65 at ser529 and thus attenuated the activity of the NF-κB pathway. The inhibition of CK2 by CX4945 can repress the viability of CRPC cells and restore their sensitivity to anti-androgen therapy by suppressing AR-V7. This finding presents a potential option for the treatment of prostate cancer, especially CRPC.

  12. Development of AR-V7 as a putative treatment selection marker for metastatic castration-resistant prostate cancer.

    PubMed

    Luo, Jun

    2016-01-01

    Prostate cancer cells demonstrate a remarkable "addiction" to androgen receptor (AR) signaling in all stages of disease progression. As such, suppression of AR signaling remains the therapeutic goal in systemic treatment of prostate cancer. A number of molecular alterations arise in patients treated with AR-directed therapies. These molecular alterations may indicate the emergence of treatment resistance and may be targeted for the development of novel agents for prostate cancer. The presence of functional androgen receptor splice variants may represent a potential explanation for resistance to abiraterone and enzalutamide, newer AR-directed agents developed to treat metastatic castration-resistant prostate cancer (mCRPC). In the last 8 years, many androgen receptor splice variants have been identified and characterized. Among these, androgen receptor splice variant-7 (AR-V7) has been investigated extensively. In AR-V7, the entire COOH-terminal ligand-binding domain of the canonical AR is truncated and replaced with a variant-specific peptide of 16 amino acids. Functionally, AR-V7 is capable of mediating constitutive nuclear localization and androgen receptor signaling in the absence of androgens, or in the presence of enzalutamide. In this review, we will focus on clinical translational studies involving detection/measurement of AR-V7. Methods have been developed to detect AR-V7 in clinical mCRPC specimens. AR-V7 can be reliably measured in both tissue and circulating tumor cells derived from mCRPC patients, making it possible to conduct both cross-sectional and longitudinal clinical correlative studies. Current evidence derived from studies focusing on detection of AR-V7 in mCRPC support its potential clinical utility as a treatment selection marker.

  13. Low-dose docetaxel, estramustine and prednisolone combination chemotherapy for castration-resistant prostate cancer

    PubMed Central

    NAKANO, MAYURA; SHOJI, SUNAO; HIGURE, TARO; KAWAKAMI, MASAYOSHI; TOMONAGA, TETSURO; TERACHI, TOSHIRO; UCHIDA, TOYOAKI

    2016-01-01

    The objective of this study was to report our experience with weekly low-dose docetaxel (DOC) chemotherapy for patients with castration-resistant prostate cancer (CRPC). From 2007 to 2014, 39 consecutive patients received weekly low-dose DOC; the oncological effectiveness, side effects and tolerability were prospectively analyzed. The median patient age, serum prostate-specific antigen (PSA) level and Gleason score at diagnosis of prostate cancer were 71 years (range, 55–83 years), 187 ng/ml (range, 2.0–1711 ng/ml) and 8 (range, 5–10), respectively. The median number of cycles of DOC was 7 (range, 1–45 cycles). Of the 39 patients, the PSA level decreased by >50% in 13 (33%). In the multivariate analysis of prediction of patient overall survival, a decrease of the PSA level to <50% was a significant predictor (hazard ratio = 6.913; 95% confidence interval: 1.147–41.669; P=0.035). The median cancer-specific overall survival from the diagnosis of CRPC was 16.7 months (range, 2–54 months). Grade 3 toxicities were observed in 5 patients (13%); specifically, limb edema, nausea and hepatic disorders were detected in 2 (5%), 2 (5%) and 1 patient (3%), respectively. Treatment-related death (grade 5) occurred in 1 patient due to interstitial pneumonia after two courses of chemotherapy. The chemotherapy was completed in the majority of the patients (n=37, 94.8%) in the outpatient department, without interruption. These findings suggest that weekly low-dose DOC is feasible and safe for selected patients with CRPC, without treament with novel agents, such as abiraterone, enzalutamide and cabazitaxel. PMID:27284427

  14. Expression of AR-V7 in Circulating Tumour Cells Does Not Preclude Response to Next Generation Androgen Deprivation Therapy in Patients with Castration Resistant Prostate Cancer.

    PubMed

    Bernemann, Christof; Schnoeller, Thomas J; Luedeke, Manuel; Steinestel, Konrad; Boegemann, Martin; Schrader, Andres J; Steinestel, Julie

    2017-01-01

    The androgen receptor splice variant AR-V7 has recently been discussed as a predictive biomarker for nonresponse to next-generation androgen deprivation therapy (ADT) in patients with castration-resistant prostate cancer. However, we recently identified one patient showing a response from abiraterone despite expression of AR-V7 in his circulating tumour cells (CTC). Therefore, we precisely assessed the response in a cohort of 21 AR-V7 positive castration-resistant prostate cancer patients who had received therapy with abiraterone or enzalutamide. We detected a subgroup of six AR-V7 positive patients showing benefit from either abiraterone or enzalutamide. Their progression free survival was 26 d (censored) to 188 d. Four patients displayed a prostate-specific antigen decrease of >50%. When analysing prior therapies, we noticed that only one of the six patients had received next-generation ADT prior to CTC collection. As a result, we conclude that AR-V7 status in CTC cannot entirely predict nonresponse to next generation ADT and AR-V7-positive patients should not be systematically denied abiraterone or enzalutamide treatment, especially as effective alternative treatment options are still limited. A subgroup of patients can benefit from abiraterone and/or enzalutamide despite detection of AR-V7 splice variants in their circulating tumour cells. Copyright © 2016 European Association of Urology. Published by Elsevier B.V. All rights reserved.

  15. A phase II trial of dasatinib in patients with metastatic castration-resistant prostate cancer treated previously with chemotherapy

    PubMed Central

    Twardowski, Przemyslaw W.; Beumer, Jan H.; Chen, C.S.; Kraft, Andrew S.; Chatta, Gurkamal S.; Mitsuhashi, Masato; Ye, Wei; Christner, Susan M.; Lilly, Michael B.

    2014-01-01

    There is a need for efficacious therapies for metastatic castration-resistant prostate cancer (mCRPC) after disease progression on docetaxel. The SRC tyrosine kinase and its related family members may be important drivers of prostate cancer and can be inhibited by dasatinib. mCRPC patients, after one previous chemotherapy, started dasatinib at 70mg twice daily, amended to 100mg daily. The primary endpoint was the disease control (DC) rate, defined as complete response (CR), partial response (PR), or stable disease (SD) in prostate specific antigen (PSA), RECIST, bone scan, and FACT-P score. Up to 41 patients were to be accrued (two-stage design, 21+20) to rule out a null-hypothesized effect of 5 versus 20% (α=0.05, β=0.1). Secondary endpoints included progression-free survival, toxicity, and pharmacokinetic and pharmacodynamic correlatives. Of 38 patients, 27 were evaluable for response or toxicity. The median duration of therapy was 55 days (6–284). Five patients showed DC after 8 weeks of therapy (18.5% DC, 95% CI: 6.3–38.1%). One PR (3.7% response rate, 95% CI: 0.1–19.0%) was observed in a patient treated for 284 days. Twelve patients (43%) discontinued treatment for toxicity. Dasatinib induced a decrease in phytohemagglutinin-stimulated CSF2, CD40L, GZMB, and IL-2 mRNAs in blood cells, indicating target engagement. Decreases in plasma IL-6 and bone alkaline phosphatase, and in urinary N-telopeptide, were associated with DC. Dasatinib has definite but limited activity in advanced mCRPC, and was poorly tolerated. The observation of a patient with prolonged, objective, clinically significant benefit warrants molecular profiling to select the appropriate patient population. PMID:23652277

  16. Carbidopa enhances antitumoral activity of bicalutamide on the androgen receptor-axis in castration-resistant prostate tumors.

    PubMed

    Thomas, Christian; Wafa, Latif A; Lamoureux, Francois; Cheng, Helen; Fazli, Ladan; Gleave, Martin E; Rennie, Paul S

    2012-06-01

    Response to bicalutamide after castration failure is not durable and treatment options at this stage are limited. Carbidopa, an L-dopa decarboxylase (AR-coactivator) inhibitor, has been shown to retard prostate tumor growth/PSA production in xenografts. Here, we hypothesize that pharmacological targeting of the AR-axis by combination treatment with bicalutamide plus carbidopa significantly enhances antitumoral activity in vitro and in vivo compared to monotherapy with either drug. Carbidopa was tested for its ability to enhance the effects of bicalutamide on cell viability, apoptosis and PSA transactivation in LNCaP and C4-2 cells. The castration-resistant prostate cancer (CRPC) LNCaP xenograft tumor model was used in vivo. After CRPC progression, mice were treated with carbidopa (50 mg/kg) and bicalutamide (50 mg/kg) as monotherapy or in combination. Tumor volume and serum PSA were evaluated weekly. Combination treatment of carbidopa plus bicalutamide significantly inhibited cell viability in both cell lines and induced apoptosis. The combination treatment also decreased androgen-induced PSA transactivation by 62.6% in LNCaP cells and by 55.6% in C4-2 cells compared to control, while bicalutamide monotherapy reduced PSA levels by 27.5% and 29.1% in LNCaP and C4-2 cells. In vivo, bicalutamide monotherapy delayed LNCaP CRPC tumor growth rate by 72.2%, while combination treatment reduced tumor growth by 84.4% compared to control. Serum PSA was also reduced 70.6% with bicalutamide monotherapy, while combination therapy reduced PSA levels by 76.7% compared to control. This study demonstrates preclinical proof-of-principle that pharmacological targeting of prostate tumors by combination treatment of bicalutamide plus carbidopa significantly reduces AR activity, and thereby delays CRPC tumor progression in vivo. Copyright © 2011 Wiley Periodicals, Inc.

  17. Ailanthone targets p23 to overcome MDV3100 resistance in castration-resistant prostate cancer

    PubMed Central

    He, Yundong; Peng, Shihong; Wang, Jinhua; Chen, Huang; Cong, Xiaonan; Chen, Ang; Hu, Meichun; Qin, Min; Wu, Haigang; Gao, Shuman; Wang, Liguo; Wang, Xin; Yi, Zhengfang; Liu, Mingyao

    2016-01-01

    Androgen receptor (AR) antagonist MDV3100 is the first therapeutic approach in treating castration-resistant prostate cancer (CRPC), but tumours frequently become drug resistant via multiple mechanisms including AR amplification and mutation. Here we identify the small molecule Ailanthone (AIL) as a potent inhibitor of both full-length AR (AR-FL) and constitutively active truncated AR splice variants (AR-Vs). AIL binds to the co-chaperone protein p23 and prevents AR's interaction with HSP90, thus resulting in the disruption of the AR-chaperone complex followed by ubiquitin/proteasome-mediated degradation of AR as well as other p23 clients including AKT and Cdk4, and downregulates AR and its target genes in PCa cell lines and orthotopic animal tumours. In addition, AIL blocks tumour growth and metastasis of CRPC. Finally, AIL possesses favourable drug-like properties such as good bioavailability, high solubility, lack of CYP inhibition and low hepatotoxicity. In general, AIL is a potential candidate for the treatment of CRPC. PMID:27959342

  18. Metastatic castration-resistant prostate cancer in very elderly patients: challenges and solutions

    PubMed Central

    Caffo, Orazio; Maines, Francesca; Rizzo, Mimma; Kinspergher, Stefania; Veccia, Antonello

    2017-01-01

    The treatment of elderly patients with cancer is usually viewed by clinicians as a challenge, because of the age-related decline in normal organ function and the frequent concomitant administration of multiple drugs for comorbid conditions. Clinicians therefore tend not to prescribe antineoplastic agents (mainly in the case of chemotherapy) to elderly patients, with the fear of excess toxicity leading to an unfavorable cost:benefit ratio. The cutoff age defining a cancer patient as elderly is usually 70 years, but over the last 10 years clinicians have paid more attention to functional status, as evaluated by means of a comprehensive geriatric assessment and comorbidity burden, rather than chronological age. In the case of metastatic castration-resistant prostate cancer (mCRPC), depending on their age at the time of diagnosis of PC, many (if not most) of the patients are more than 70 years old, and a fair number are very elderly patients aged ≥80 years. The availability of various agents capable of significantly prolonging survival has dramatically changed the therapeutic landscape of mCRPC patients, but very elderly patients are usually underrepresented in pivotal trials. This narrative review considers the available data concerning elderly and very elderly mCRPC patients enrolled in pivotal trials and the information provided by reports of everyday clinical practice, in order to explore the challenges related to the clinical management of this special population. PMID:28053513

  19. Neuroendocrine differentiation in castration-resistant prostate cancer: a systematic diagnostic attempt.

    PubMed

    Matei, Deliu-Victor; Renne, Giuseppe; Pimentel, Marcelo; Sandri, Maria Teresa; Zorzino, Laura; Botteri, Edoardo; De Cicco, Concetta; Musi, Gennaro; Brescia, Antonio; Mazzoleni, Federica; Tringali, Valeria; Detti, Serena; de Cobelli, Ottavio

    2012-09-01

    Assessing the neuroendocrine (NE) pattern in castration-resistant prostate cancer (CRPC) may prove useful in selecting potential responders to target therapies such as somatostatin analogues. The aim of this study was to define a panel of markers or examinations appropriate to characterize NE differentiation (NED). Forty-seven patients with CRPC underwent a systematic diagnostic attempt to characterize the NE phenotype using a plasma blood test for chromogranin A (CgA) and immunohistochemical staining of needle biopsy-obtained specimens (CgA, somatostatin receptor 2 [SSTR2], Ki-67, and androgen receptors). In a subgroup of 26 patients, somatostatin receptor scintigraphy using (111)In-DTPA-d-Phe octreotide (octreotide scintigraphy; Octreoscan, Covidien, Hazelwood, MO) was also performed. NED was found in 85.1% of patients (if serum CgA, tissular CgA, and tissular SSTR2 were considered separately: 54%, 67%, and 58%, respectively). Only 15% of the 26-patient subgroup had an abnormal octreotide scintigraphy result. Although p-CgA and t-CgA were associated with more aggressive disease with a worse prognosis, patients with positive tissular SSTR2 staining had longer overall survival (OS). This systematic approach to explore the NED in a quite homogeneous group of patients with CRPC seems reproducible and appropriate. Further investigations are required to validate this panel and better characterize potential responders to targeted therapy. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Clinical Relevance of Androgen Receptor Splice Variants in Castration-Resistant Prostate Cancer.

    PubMed

    Maughan, Benjamin L; Antonarakis, Emmanuel S

    2015-12-01

    Metastatic castration-resistant prostate cancer (mCRPC) currently benefits from a wealth of treatment options, yet still remains lethal in the vast majority of patients. It is becoming increasingly understood that this disease entity continues to evolve over time, acquiring additional and diverse resistance mechanisms with each subsequent therapy used. This dynamic relationship between treatment pressure and disease resistance can be challenging for the managing clinician. The recent discovery of alternate splice variants of the androgen receptor (AR) is one potential mechanism of escape in mCRPC, and recognizing this resistance mechanism might be important for optimal treatment selection for our patients. AR-V7 appears to be the most relevant AR splice variant, and early clinical data suggest that it is a negative prognostic marker in mCRPC. Emerging evidence also suggests that detection of AR-V7 may be associated with resistance to novel hormonal therapy (abiraterone and enzalutamide) but may be compatible with sensitivity to taxane chemotherapy (docetaxel and cabazitaxel). Adding to this complexity is the observation that AR-V7 is a dynamic marker whose status may change across time and depending on selective pressures induced by different therapies. Finally, it is possible that AR-V7 may represent a therapeutic target in mCRPC if drugs can be designed that degrade or inhibit AR splice variants or block their transcriptional activity. Several such agents (including galeterone, EPI-506, and bromodomain/BET inhibitors) are now in clinical development.

  1. Lymphocyte function following radium-223 therapy in patients with metastasized, castration-resistant prostate cancer.

    PubMed

    Barsegian, Vahé; Müller, Stefan P; Möckel, Daniel; Horn, Peter A; Bockisch, Andreas; Lindemann, Monika

    2017-02-01

    Therapy with the alpha-emitter radium-223 chloride ((223)Ra) is an innovative therapeutic option in patients with metastasized, castration-resistant prostate cancer. However, radiotherapy can lead to hematopoietic toxicity. The aim of this study was to determine if (223)Ra therapy induces an impairment of cellular antimicrobial immune responses. In 11 patients receiving (223)Ra treatment, lymphocyte proliferation and the production of pro- and anti-inflammatory cytokines (interferon-γ and interleukin-10) were determined, using lymphocyte transformation testing and ELISpot, respectively. Lymphocyte function after stimulation with mitogens and microbial antigens was assessed prior to therapy and at day 1, 7 and 28 after therapy. Lymphocyte proliferation and the production of interferon-γ and interleukin-10 towards mitogens and antigens remained unchanged after therapy. Consistent with these in vitro data, we did not observe infectious complications after treatment. The results argue against an impairment of lymphocyte function after (223)Ra therapy. Thus, immune responses against pathogens should remain unaffected.

  2. Economic evaluation of sipuleucel-T immunotherapy in castration-resistant prostate cancer.

    PubMed

    Holko, Przemysław; Kawalec, Paweł

    2014-01-01

    The objective is to examine the cost-utility of sipuleucel-T immunotherapy in asymptomatic or minimally symptomatic castration-resistant prostate cancer patients. The addition of sipuleucel-T immunotherapy to standard treatment led to a gain of 0.37 quality-adjusted life-year (QALY) at an additional cost of US$104,536. The incremental cost-utility ratio was US$283,000 per QALY saved. Threshold sensitivity analyses indicated that a price reduction of at least 53%, or application in a group of patients resulting in the relative reduction in the mortality rate of at least 39%, ought to augment the economic value of this regimen. Sipuleucel-T immunotherapy treatment at the current price with 96.5% certainty is not cost-effective. The specific group of patients who will benefit more from the treatment should be revealed and treated, or the cost of the vaccine should be lowered significantly to increase its economic value. Accounting for crossover treatment in control patients improves sipuleucel-T's value (US$132,000 per QALY saved) although further investigation is necessary.

  3. Aurora A regulates expression of AR-V7 in models of castrate resistant prostate cancer

    PubMed Central

    Jones, Dominic; Noble, Martin; Wedge, Steve R.; Robson, Craig N.; Gaughan, Luke

    2017-01-01

    Androgen receptor variants (AR-Vs) provide a mechanism of therapy evasion in castrate-resistant prostate cancer (CRPC), yet mechanisms of regulation remain largely unknown. Here we investigate the role of Aurora A kinase on AR-Vs in models of CRPC and show depletion of Aurora A reduces AR-V target gene expression. Importantly, knockdown of Aurora A reconfigures splicing of AR pre-mRNA to discriminately down-regulate synthesis of AR-V transcripts, including AR-V7, without effecting full-length AR mRNA; and as a consequence, AR-V-driven proliferation and survival of CRPC cells is markedly reduced. Critically, these effects are reproduced by Aurora A inhibition. We show that Aurora A levels increase in advanced disease and AURKA is an AR-V target gene demonstrating a positive feedback mechanism of androgenic signalling in CRPC. In all, our data suggests that Aurora A plays a pivotal role in regulation of AR-V7 expression and represents a new therapeutic target in CRPC. PMID:28205582

  4. Aurora A regulates expression of AR-V7 in models of castrate resistant prostate cancer.

    PubMed

    Jones, Dominic; Noble, Martin; Wedge, Steve R; Robson, Craig N; Gaughan, Luke

    2017-02-16

    Androgen receptor variants (AR-Vs) provide a mechanism of therapy evasion in castrate-resistant prostate cancer (CRPC), yet mechanisms of regulation remain largely unknown. Here we investigate the role of Aurora A kinase on AR-Vs in models of CRPC and show depletion of Aurora A reduces AR-V target gene expression. Importantly, knockdown of Aurora A reconfigures splicing of AR pre-mRNA to discriminately down-regulate synthesis of AR-V transcripts, including AR-V7, without effecting full-length AR mRNA; and as a consequence, AR-V-driven proliferation and survival of CRPC cells is markedly reduced. Critically, these effects are reproduced by Aurora A inhibition. We show that Aurora A levels increase in advanced disease and AURKA is an AR-V target gene demonstrating a positive feedback mechanism of androgenic signalling in CRPC. In all, our data suggests that Aurora A plays a pivotal role in regulation of AR-V7 expression and represents a new therapeutic target in CRPC.

  5. Resistance to Novel Antiandrogen Therapies in Metastatic Castration-Resistant Prostate Cancer

    PubMed Central

    Boudadi, Karim; Antonarakis, Emmanuel S.

    2016-01-01

    Despite the introduction of novel therapies that maximally decrease androgen-receptor (AR) signaling activity, metastatic castration-resistant prostate cancer (mCRPC) remains a lethal disease. Even though abiraterone and enzalutamide represent breakthroughs in the treatment of mCRPC and have demonstrated significant survival benefits, a significant proportion of patients have primary resistance to these agents and virtually all patients develop secondary resistance. While the mechanisms of resistance to these agents are not fully understood, many hypotheses of AR-dependent and AR-independent mechanisms are emerging, including upregulation of AR and cytochrome P450 17α-hydroxylase/17,20-lyase (CYP17), induction of AR splice variants, AR point mutations, upregulation of glucocorticoid receptor, activation of alternative oncogenic signaling pathways, neuroendocrine transformation, and immune evasion via programmed death-ligand 1 upregulation. The aim of this review is to summarize the most clinically relevant mechanisms of resistance to novel androgen-directed agents, focusing on escape from enzalutamide and abiraterone. PMID:27013902

  6. A combination of sorafenib and nilotinib reduces the growth of castrate-resistant prostate cancer

    PubMed Central

    Archibald, Monica; Pritchard, Tara; Nehoff, Hayley; Rosengren, Rhonda J; Greish, Khaled; Taurin, Sebastien

    2016-01-01

    Castrate-resistant prostate cancer (CRPC) remains incurable due to the lack of effective therapies. Several tyrosine kinases have been implicated in the development and growth of CRPC, as such targeting these kinases may offer an alternative therapeutic strategy. We established the combination of two tyrosine kinase inhibitors (TKIs), sorafenib and nilotinib, as the most cytotoxic. In addtion, to improve their bioavailability and reduce their metabolism, we encapsulated sorafenib and nilotinib into styrene-co-maleic acid micelles. The micelles’ charge, size, and release rate were characterized. We assessed the effect of the combination on the cytotoxicity, cell cycle, apoptosis, protein expression, tumor spheroid integrity, migration, and invasion. The micelles exhibited a mean diameter of 100 nm, a neutral charge, and appeared highly stable. The micellar TKIs promoted greater cytotoxicity, decreased cell proliferation, and increased apoptosis relative to the free TKIs. In addition, the combination reduced the expression and activity of several tyrosine kinases and reduced tumor spheroid integrity and metastatic potential of CRPC cell lines more efficiently than the single treatments. The combination increased the therapeutic potential and demonstrated the relevance of a targeted combination therapy for the treatment of CRPC. In addition, the efficacy of the encapsulated drugs provides the basis for an in vivo preclinical testing. PMID:26811677

  7. Downregulation of c-SRC kinase CSK promotes castration resistant prostate cancer and pinpoints a novel disease subclass.

    PubMed

    Yang, Chih-Cheng; Fazli, Ladan; Loguercio, Salvatore; Zharkikh, Irina; Aza-Blanc, Pedro; Gleave, Martin E; Wolf, Dieter A

    2015-09-08

    SRC kinase is activated in castration resistant prostate cancer (CRPC), phosphorylates the androgen receptor (AR), and causes its ligand-independent activation as a transcription factor. However, activating SRC mutations are exceedingly rare in human tumors, and mechanisms of ectopic SRC activation therefore remain largely unknown. Performing a functional genomics screen, we found that downregulation of SRC inhibitory kinase CSK is sufficient to overcome growth arrest induced by depriving human prostate cancer cells of androgen. CSK knockdown led to ectopic SRC activation, increased AR signaling, and resistance to anti-androgens. Consistent with the in vitro observations, stable knockdown of CSK conferred castration resistance in mouse xenograft models, while sensitivity to the tyrosine kinase inhibitor dasatinib was retained. Finally, CSK was found downregulated in a distinct subset of CRPCs marked by AR amplification and ETS2 deletion but lacking PTEN and RB1 mutations. These results identify CSK downregulation as a principal driver of SRC activation and castration resistance and validate SRC as a drug target in a molecularly defined subclass of CRPCs.

  8. Downregulation of c-SRC kinase CSK promotes castration resistant prostate cancer and pinpoints a novel disease subclass

    PubMed Central

    Yang, Chih-Cheng; Fazli, Ladan; Loguercio, Salvatore; Zharkikh, Irina; Aza-Blanc, Pedro; Gleave, Martin E.; Wolf, Dieter A.

    2015-01-01

    SRC kinase is activated in castration resistant prostate cancer (CRPC), phosphorylates the androgen receptor (AR), and causes its ligand-independent activation as a transcription factor. However, activating SRC mutations are exceedingly rare in human tumors, and mechanisms of ectopic SRC activation therefore remain largely unknown. Performing a functional genomics screen, we found that downregulation of SRC inhibitory kinase CSK is sufficient to overcome growth arrest induced by depriving human prostate cancer cells of androgen. CSK knockdown led to ectopic SRC activation, increased AR signaling, and resistance to anti-androgens. Consistent with the in vitro observations, stable knockdown of CSK conferred castration resistance in mouse xenograft models, while sensitivity to the tyrosine kinase inhibitor dasatinib was retained. Finally, CSK was found downregulated in a distinct subset of CRPCs marked by AR amplification and ETS2 deletion but lacking PTEN and RB1 mutations. These results identify CSK downregulation as a principal driver of SRC activation and castration resistance and validate SRC as a drug target in a molecularly defined subclass of CRPCs. PMID:26091350

  9. A Phase II Trial of Abiraterone Combined with Dutasteride for Men with Metastatic Castration-Resistant Prostate Cancer.

    PubMed

    McKay, Rana R; Werner, Lillian; Mostaghel, Elahe A; Lis, Rosina; Voznesensky, Olga; Zhang, Zhenwei; Marck, Brett T; Matsumoto, Alvin M; Domachevsky, Liran; Zukotynski, Katherine A; Bhasin, Manoj; Bubley, Glenn J; Montgomery, Bruce; Kantoff, Philip W; Balk, Steven P; Taplin, Mary-Ellen

    2017-02-15

    Purpose: Despite the efficacy of abiraterone, a CYP17A1 inhibitor, in metastatic castration-resistant prostate cancer (CRPC), nearly all patients develop resistance. The purpose of this phase II study was to evaluate mechanisms of resistance to more complete androgen synthesis inhibition with abiraterone and dutasteride.Experimental Design: Eligible patients with metastatic CRPC underwent a baseline metastasis biopsy. Patients received abiraterone and prednisone for two 4-week cycles. After this time, high-dose dutasteride (3.5 mg daily) was added. Patients continued therapy until study withdrawal or radiographic progression. Repeat metastasis biopsy was obtained at progression. The primary endpoint was to assess mechanisms of resistance. Serum hormone and abiraterone levels were assessed. Tissue was assessed for androgen receptor (AR) and AR splice variant-7 (ARV7) expression.Results: Forty patients were enrolled. Sixty percent (n = 24) achieved a ≥50% reduction in prostate-specific antigen (PSA). The median time to radiographic progression was 11 months. Nearly all baseline (n = 29 of 31) and posttreatment (n = 16 of 16) tumors tested for AR nuclear expression were positive. Of those tested, ARV7 expression was present in 48% (n = 10 of 21) of baseline and 42% (n = 5 of 12) of treatment discontinuation specimens. Compared with patients with higher serum abiraterone levels at treatment discontinuation, patients with lower levels had higher circulating androgens.Conclusions: Despite increased androgen synthesis inhibition, we demonstrate that tumor AR axis remains important in disease progression. We highlight that abiraterone metabolism and pharmacokinetics may play a role in resistance. The noncomparative design limits conclusions on the efficacy of dual therapy with abiraterone and dutasteride, but the results support development of further multifaceted approaches toward AR inhibition. Clin Cancer Res; 23(4); 935-45. ©2016 AACR.

  10. Activation of P-TEFb by Androgen Receptor-Regulated Enhancer RNAs in Castration-Resistant Prostate Cancer.

    PubMed

    Zhao, Yu; Wang, Liguo; Ren, Shancheng; Wang, Lan; Blackburn, Patrick R; McNulty, Melissa S; Gao, Xu; Qiao, Meng; Vessella, Robert L; Kohli, Manish; Zhang, Jun; Karnes, R Jeffrey; Tindall, Donald J; Kim, Youngsoo; MacLeod, Robert; Ekker, Stephen C; Kang, Tiebang; Sun, Yinghao; Huang, Haojie

    2016-04-19

    The androgen receptor (AR) is required for castration-resistant prostate cancer (CRPC) progression, but the function and disease relevance of AR-bound enhancers remain unclear. Here, we identify a group of AR-regulated enhancer RNAs (e.g., PSA eRNA) that are upregulated in CRPC cells, patient-derived xenografts (PDXs), and patient tissues. PSA eRNA binds to CYCLIN T1, activates P-TEFb, and promotes cis and trans target gene transcription by increasing serine-2 phosphorylation of RNA polymerase II (Pol II-Ser2p). We define an HIV-1 TAR RNA-like (TAR-L) motif in PSA eRNA that is required for CYCLIN T1 binding. Using TALEN-mediated gene editing we further demonstrate that this motif is essential for increased Pol II-Ser2p occupancy levels and CRPC cell growth. We have uncovered a P-TEFb activation mechanism and reveal altered eRNA expression that is related to abnormal AR function and may potentially be a therapeutic target in CRPC.

  11. A phase II study of sorafenib in combination with bicalutamide in patients with chemotherapy-naive castration resistant prostate cancer.

    PubMed

    Beardsley, Emma K; Hotte, Sebastien J; North, Scott; Ellard, Susan L; Winquist, Eric; Kollmannsberger, Christian; Mukherjee, Som D; Chi, Kim N

    2012-08-01

    The objective of this trial was to evaluate the clinical effects of sorafenib, a multi-targeted kinase inhibitor, in combination with androgen receptor blockade in patients with castration-resistant prostate cancer. This was a multicenter, two-stage, phase 2 trial. Eligible patients had rising PSA, minimal symptoms and were chemotherapy-naïve. Sorafenib 400 mg twice daily was administered with bicalutamide 50 mg once daily on a 28-day cycle. The primary endpoint was PSA response (≥ 50% decline) or stable disease ≥ 6 months. 39 patients were enrolled including eight without clinical evidence of metastases. Eighteen (47%) patients have had either a PSA response or stable disease ≥ 6 months. PSA declines of ≥ 50% occurred in 12 (32%) of 38 assessable patients, including seven of 27 patients (26%) with prior anti-androgen use. Median time to treatment failure was 5.5 months (95%CI = 4.8.1-8.3). Grade ≥ 3 adverse events included fatigue, skin rash, and hand-foot syndrome. PSA declines and stable disease were observed with a combination of sorafenib and bicalutamide including in patients previously progressing on bicalutamide. Strategies to combine multi-targeted kinase inhibitors with hormonal therapies warrant further study in patients with CRPC.

  12. Understanding and overcoming the mechanisms of primary and acquired resistance to abiraterone and enzalutamide in castration resistant prostate cancer.

    PubMed

    Buttigliero, Consuelo; Tucci, Marcello; Bertaglia, Valentina; Vignani, Francesca; Bironzo, Paolo; Di Maio, Massimo; Scagliotti, Giorgio Vittorio

    2015-12-01

    In recent years, in castration resistant prostate cancer (CRPC), several new drugs have been approved that prolong overall survival, including enzalutamide and abiraterone, two new-generation hormonal therapies. Despite the demonstrated benefit of these agents, not all patients with CRPC are responsive to treatment, the gain in median progression-free survival with these therapies compared to standard of care is, rather disappointingly, still less than six months and the appearance of acquired resistance is almost universal. Approximately one third of patients treated with abiraterone and 25% of those treated with enzalutamide show primary resistance to these agents. Even if the mechanisms of resistance to these agents are not fully defined, many hypotheses are emerging, including systemic and intratumoral androgen biosynthesis up-regulation, androgen receptor (AR) gene mutations and amplifications, alteration of pathways involved in cross-talk with AR signaling, glucocorticoid receptor overexpression, neuroendocrine differentiation, immune system deregulation and others. The aim of this paper is to review currently available data about mechanisms of resistance to abiraterone and enzalutamide, and to discuss how these mechanisms could be potentially overcome through novel therapeutic agents.

  13. Exploitation of Castration-Resistant Prostate Cancer Transcription Factor Dependencies by the Novel BET Inhibitor ABBV-075.

    PubMed

    Faivre, Emily J; Wilcox, Denise; Lin, Xiaoyu; Hessler, Paul; Torrent, Maricel; He, Wei; Uziel, Tamar; Albert, Daniel H; McDaniel, Keith; Kati, Warren; Shen, Yu

    2017-01-01

    Competitive inhibitors of acetyl-lysine binding to the bromodomains of the BET (bromodomain and extra terminal) family are being developed for the treatment of solid and hematologic malignancies. The function of BET family member BRD4 at enhancers/superenhancers has been shown to sustain signal-dependent or pathogenic gene expression programs. Here, the hypothesis was tested that the transcription factor drivers of castration-resistant prostate cancer (CRPC) clinical progression, including the androgen receptor (AR), are critically dependent on BRD4 and thus represent a sensitive solid tumor indication for the BET inhibitor ABBV-075. DHT-stimulated transcription of AR target genes was inhibited by ABBV-075 without significant effect on AR protein expression. Furthermore, ABBV-075 disrupted DHT-stimulated recruitment of BET family member BRD4 to gene-regulatory regions cooccupied by AR, including the well-established PSA and TMPRSS2 enhancers. Persistent BET inhibition disrupted the composition and function of AR-occupied enhancers as measured by a reduction in AR and H3K27Ac ChIP signal and inhibition of enhancer RNA transcription. ABBV-075 displayed potent antiproliferative activity in multiple models of resistance to second-generation antiandrogens and inhibited the activity of the AR splice variant AR-V7 and ligand-binding domain gain-of-function mutations, F877L and L702H. ABBV-075 was also a potent inhibitor of MYC and the TMPRSS2-ETS fusion protein, important parallel transcription factor drivers of CRPC.

  14. Indirect comparison between abiraterone acetate and enzalutamide for the treatment of metastatic castration-resistant prostate cancer: a systematic review.

    PubMed

    Zhang, Wei; Wu, Teng-Yun; Chen, Qi; Shi, Xiao-Lei; Xiao, Guang-An; Zhao, Lin; Xu, Chuan-Liang; Zhou, Tie; Sun, Ying-Hao

    2017-01-01

    This study was designed to evaluate the efficacy, tolerability, and sequential administration of abiraterone acetate (AA) and enzalutamide (Enz) for metastatic castration-resistant prostate cancer (mCRPC). A literature search was performed with PubMed, Embase, and Web of Science databases to identify relevant studies. Reviewed literature included published phase III trials of AA or Enz in mCRPC and studies regarding their sequential administration. Given the difference in control arms in AA (active comparator) and Enz (true placebo) randomized phase III studies, indirect comparisons between AA and Enz in mCRPC showed no statistically significant difference in overall survival in prechemotherapy and postchemotherapy settings (HR: 0.90, 95% CI, 0.73-1.11; HR: 0.85, 95% CI, 0.68-1.07). Compared with AA, Enz may better outperform control arms in treating mCRPC both before and after chemotherapy regarding secondary endpoints based on indirect comparisons: time to prostate-specific antigen (PSA) progression (HR: 0.34, 95% CI, 0.28-0.42; HR: 0.40, 95% CI, 0.30-0.53), radiographic progression-free survival (HR: 0.37, 95% CI, 0.28-0.48; HR: 0.61, 95% CI, 0.50-0.74), and PSA response rate (OR: 18.29, 95% CI, 11.20-29.88; OR: 10.69, 95% CI, 3.92-29.20). With regard to the effectiveness of Enz following AA or AA following Enz, recent retrospective case series reported overall survival and secondary endpoints for patients with mCRPC progression after chemotherapy. However, confirmatory head-to-head trials are necessary to determine the optimal sequencing of these agents.

  15. A phase II study of GW786034 (pazopanib) with or without bicalutamide in patients with castration-resistant prostate cancer.

    PubMed

    Sridhar, Srikala S; Joshua, Anthony M; Gregg, Richard; Booth, Christopher M; Murray, Nevin; Golubovic, Jovana; Wang, Lisa; Harris, Pamela; Chi, Kim N

    2015-04-01

    Pazopanib is an oral vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitor. In this randomized, open label phase II study, pazopanib alone or in combination with bicalutamide was evaluated in patients with chemotherapy-naive castration-resistant prostate cancer (CRPC). Patients received either pazopanib 800 mg daily (arm A) or pazopanib 800 mg plus bicalutamide 50 mg daily (arm B). A 2-stage study design was used, and the primary endpoint was prostate-specific antigen (PSA) response rate (defined as a confirmed ≥ 50% decline from baseline). A total of 23 patients (arm A, 10; arm B, 13) were accrued. The main grade 3+ toxicities were hypertension, fatigue, decreased lymphocytes, and increased alanine transaminase. Owing to significant toxicity, the protocol was amended after the first 11 patients and the pazopanib starting dose was reduced to 600 mg daily. In arm A, of 9 evaluable patients, there was 1 patient (11%) with a PSA response, 3 (33%) with stable PSA, and 5 (56%) with PSA progression; in arm B, of 12 evaluable patients, there were 2 patients (17%) with PSA responses, 6 (50%) with stable PSA, and 4 (33%) with PSA progression. Median progression-free survival was similar in both arms at 7.3 months (95% CI, 2.5 months to not reached). Long-term stable disease was seen in 4 patients who remained on treatment for 18 months (arm A), 26 months (arm A), 35 months (arm B), and 52 months (arm B). In this unselected patient population, pazopanib either alone or in combination with bicalutamide failed to show sufficient activity to warrant further evaluation. However, 4 patients had long-term benefit, suggesting that targeting the VEGFR pathway may still be relevant in selected patients and emphasizing the need for improved predictive markers for patients with CRPC. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Early Prediction of Therapy Response to Abiraterone Acetate Using PSA Subforms in Patients with Castration Resistant Prostate Cancer

    PubMed Central

    Schlack, Katrin; Krabbe, Laura-Maria; Fobker, Manfred; Schrader, Andres Jan; Semjonow, Axel; Boegemann, Martin

    2016-01-01

    The purpose of this study was to evaluate the prognostic ability of early changes of total prostate specific antigen (tPSA), free PSA (fPSA), [−2]proPSA and the Prostate Health Index (PHI) following initiation of Abiraterone-therapy in men with castration resistant prostate cancer (mCRPC). In 25 patients, PSA-subforms were analyzed before and at 8–12 weeks under therapy as prognosticators of progression-free-survival (PFS) and overall survival (OS). Comparing patients with a PFS < vs. ≥12 months by using Mann–Whitney–Wilcoxon Tests, the relative-median-change of tPSA (−0.1% vs. −86.8%; p = 0.02), fPSA (12.1% vs. −55.3%; p = 0.03) and [−2]proPSA (8.1% vs. −59.3%; p = 0.05) differed significantly. For men with ≤ vs. >15 months of OS there was a non-significant trend for a difference in the relative-median-change of fPSA (17.0% vs. −46.3%; p = 0.06). In Kaplan–Meier analyses, declining fPSA and [−2]proPSA were associated with a longer median PFS (13 months, 95% confidence interval (CI): 9.6–16.4 vs. 10 months, 95% CI: 3.5–16.5; p = 0.11), respectively. Correspondingly, decreasing fPSA and [−2]proPSA values indicated an OS of 32 months (95% CI: not reached (NR)) compared to 21 months in men with rising values (95% CI: 7.7–34.3; p = 0.14), respectively. We concluded that the addition of fPSA- and [−2]proPSA-changes to tPSA-information might be further studied as potential markers of early Abiraterone response in mCRPC patients. PMID:27618028

  17. Integrating bone targeting radiopharmaceuticals into the management of patients with castrate-resistant prostate cancer with symptomatic bone metastases.

    PubMed

    Blacksburg, Seth R; Witten, Matthew R; Haas, Jonathan A

    2015-03-01

    Metastatic castrate-resistant prostate cancer (CRPC) refers to the disease state in which metastatic prostate cancer fails to respond to androgen deprivation therapy (ADT). This can be manifest as a rising PSA, increase in radiographically measurable disease, or progression of clinical disease. Roughly 90 % of men with metastatic prostate cancer have bone metastases, which is a predictor of both morbidity and mortality. Historically, treatment has been palliative, consisting of external beam radiation therapy (EBRT) and pharmacological analgesics for pain control and osteoclast inhibitors, such as bisphosphonates and denosumab to mitigate skeletal-related events. Older radiopharmaceuticals, such as Strontium-89 and Samarium-153, are Beta-emitting agents that were found to provide palliation but were without survival benefit and carried high risks of myelosuppression. Radium-223 is an Alpha-emitting radiopharmaceutical that has demonstrated a significant overall survival benefit in men with metastatic CRPC, delay to symptomatic skeletal events (SSEs), and improvement in pain control, with a favorable toxicity profile compared with placebo. Unlike EBRT, Radium-223 has systemic uptake, with the potential to address several bone metastases concurrently and provides overall survival benefit. It is a simple administration with minimal complexity and shielding requirements in experienced hands. EBRT appears to provide a more rapid and dramatic palliative benefit to any given lesion. Because Radium-223 has limited myelosuppression, the two can be thoughtfully integrated, along with multiple agents, for the treatment of men with CRPC with symptomatic bone metastases. Given its excellent safety profile, there is interest and anecdotal safety combining Radium-223 with therapies, such as abiraterone and enzalutamide. Formal recommendations regarding combination therapies will require clinical trials. The use of Alpha-emitting radiopharmaceuticals in castrate-sensitive disease

  18. Early Prediction of Therapy Response to Abiraterone Acetate Using PSA Subforms in Patients with Castration Resistant Prostate Cancer.

    PubMed

    Schlack, Katrin; Krabbe, Laura-Maria; Fobker, Manfred; Schrader, Andres Jan; Semjonow, Axel; Boegemann, Martin

    2016-09-09

    The purpose of this study was to evaluate the prognostic ability of early changes of total prostate specific antigen (tPSA), free PSA (fPSA), [-2]proPSA and the Prostate Health Index (PHI) following initiation of Abiraterone-therapy in men with castration resistant prostate cancer (mCRPC). In 25 patients, PSA-subforms were analyzed before and at 8-12 weeks under therapy as prognosticators of progression-free-survival (PFS) and overall survival (OS). Comparing patients with a PFS < vs. ≥12 months by using Mann-Whitney-Wilcoxon Tests, the relative-median-change of tPSA (-0.1% vs. -86.8%; p = 0.02), fPSA (12.1% vs. -55.3%; p = 0.03) and [-2]proPSA (8.1% vs. -59.3%; p = 0.05) differed significantly. For men with ≤ vs. >15 months of OS there was a non-significant trend for a difference in the relative-median-change of fPSA (17.0% vs. -46.3%; p = 0.06). In Kaplan-Meier analyses, declining fPSA and [-2]proPSA were associated with a longer median PFS (13 months, 95% confidence interval (CI): 9.6-16.4 vs. 10 months, 95% CI: 3.5-16.5; p = 0.11), respectively. Correspondingly, decreasing fPSA and [-2]proPSA values indicated an OS of 32 months (95% CI: not reached (NR)) compared to 21 months in men with rising values (95% CI: 7.7-34.3; p = 0.14), respectively. We concluded that the addition of fPSA- and [-2]proPSA-changes to tPSA-information might be further studied as potential markers of early Abiraterone response in mCRPC patients.

  19. Factors Associated With Survival Following Radium-223 Treatment for Metastatic Castration-resistant Prostate Cancer.

    PubMed

    Wong, William W; Anderson, Eric M; Mohammadi, Homan; Daniels, Thomas B; Schild, Steve E; Keole, Sameer R; Choo, C Richard; Tzou, Katherine S; Bryce, Alan H; Ho, Thai H; Quevedo, Fernando J; Vora, Sujay A

    2017-04-26

    Radium-223 ((223)Ra) improves survival in patients with metastatic castration-resistant prostate cancer (mCRPC). This retrospective analysis was performed to better understand its efficacy in routine clinical practice and identify factors associated with survival. Sixty-four patients with mCRPC who received (223)Ra between 2013 and 2015 were the basis of this retrospective study. Clinical outcomes and patient characteristics were obtained. Potential prognostic factors for survival were evaluated by univariate analysis using the log-rank test and multivariate analysis using the Cox proportional hazard method. The median survival was 12.9 months. Twenty-one patients (33%) developed a skeletal event, and the median time to the first skeletal event was 4.4 months. In univariate analysis, factors significantly associated with survival included: no prior chemotherapy, ≤ 5 bone metastases, baseline prostate-specific antigen (PSA) ≤ 36 ng/mL, baseline alkaline phosphatase (ALP) < 115 U/L, baseline hemoglobin > 12 g/dL, ALP response after (223)Ra treatment, PSA decrease during (223)Ra treatment, and absence of > 25% PSA increase during (223)Ra treatment. In multivariate analysis, 4 factors remained significant: no prior chemotherapy, ≤ 5 bone metastases, baseline ALP < 115 U/L, and ALP response after (223)Ra treatment. When (223)Ra is administered in routine clinical practice, clinical outcomes can be more variable than those reported in the randomized study owing to patient heterogeneity. Four factors were identified to be significantly associated with survival after (223)Ra treatment. These pretreatment factors may be used as stratification factors in future studies to investigate whether (223)Ra would be more effective for patients with newly diagnosed metastatic disease that is sensitive to androgen deprivation therapy. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Patient experience in the treatment of metastatic castration-resistant prostate cancer: state of the science

    PubMed Central

    Nussbaum, N; George, D J; Abernethy, A P; Dolan, C M; Oestreicher, N; Flanders, S; Dorff, T B

    2016-01-01

    Background: Contemporary therapies for metastatic castration-resistant prostate cancer (mCRPC) have shown survival improvements, which do not account for patient experience and health-related quality of life (HRQoL). Methods: This literature review included a search of MEDLINE for randomized clinical trials enrolling ⩾50 patients with mCRPC and reporting on patient-reported outcomes (PROs) since 2010. Results: Nineteen of 25 publications describing seven treatment regimens (10 clinical trials and nine associated secondary analyses) met the inclusion criteria and were critically appraised. The most commonly used measures were the Functional Assessment of Cancer Therapy-Prostate (n=5 trials) and Brief Pain Inventory Short Form (n=4 trials) questionnaires. The published data indicated that HRQoL and pain status augmented the clinical efficacy data by providing a better understanding of treatment impact in mCRPC. Abiraterone acetate and prednisone, enzalutamide, radium-223 dichloride and sipuleucel-T offered varying levels of HRQoL benefit and/or pain mitigation versus their respective comparators, whereas three treatments (mitoxantrone, estramustine phosphate and docetaxel, and cabazitaxel) had no meaningful impact on HRQoL or pain. The main limitation of the data were that the PROs utilized were not developed for use in mCRPC patients and hence may not have comprehensively captured symptoms important to this population. Conclusions: Recently published randomized clinical trials of new agents for mCRPC have captured elements of the patient experience while on treatment. Further research is required to standardize methods for measuring, quantifying and reporting on HRQoL and pain in patients with mCRPC in the clinical practice setting. PMID:26832363

  1. Treatment of castration-resistant prostate cancer and bone metastases with radium-223 dichloride

    PubMed Central

    Lien, Lise Marie E; Tvedt, Birger; Heinrich, Daniel

    2015-01-01

    Radium-223 dichloride (Ra-223) is the first α-particle emitting radiopharmaceutical to be approved for the treatment of patients with castration-resistant prostate cancer and associated bone metastases, and the first bone-targeting agent to significantly improve patient overall survival whilst reducing pain and the symptomatic skeletal events (SSEs) associated with bone metastases. Ra-223 exhibits a favourable safety profile, with low myelosuppression rates and fewer adverse events than placebo. Compared with other approved radiopharmaceuticals, the α-particle emitting Ra-223 has a high biological efficiency and a short penetration range, potentially sparing bone marrow toxicity and limiting unwanted exposure. Ra-223 has a short half-life and decays to a stable product, reducing the problem of storage and disposal associated with radiopharmaceuticals. Ra-223 offers a new treatment option with great potential in this setting. However, concerns remain amongst patients, their families and health care professionals over the use of radiopharmaceuticals. This article, which draws on the experiences of health care workers during the ALSYMPCA (ALpharadin in SYMtomatic Prostate CAncer) study, reviews the clinical development of Ra-223, highlighting the key issues for the uro-oncology nurse who has a pivotal role within the multi-disciplinary team (MDT) to ensure safe and effective treatment to the patient. The role of the uro-oncology nurse is multifaceted, including patient pre-assessment and post-treatment monitoring and coordination of the MDT. In addition, their role in communicating with and educating those involved with Ra-223 on what to expect from the agent can alleviate fears associated with its use. PMID:26097500

  2. 11-Ketotestosterone and 11-Ketodihydrotestosterone in Castration Resistant Prostate Cancer: Potent Androgens Which Can No Longer Be Ignored

    PubMed Central

    Pretorius, Elzette; Africander, Donita J.; Vlok, Maré; Quanson, Jonathan

    2016-01-01

    Dihydrotestosterone (DHT) is regarded as the most potent natural androgen and is implicated in the development and progression of castration resistant prostate cancer (CRPC). Under castrate conditions, DHT is produced from the metabolism of the adrenal androgen precursors, DHEA and androstenedione. Recent studies have shown that the adrenal steroid 11β-hydroxyandrostenedione (11OHA4) serves as the precursor to the androgens 11-ketotestosterone (11KT) and 11-ketodihydrotestosterone (11KDHT). In this study we comprehensively assess the androgenic activity of 11KT and 11KDHT. This is the first study, to our knowledge, to show that 11KT and 11KDHT, like T and DHT, are potent and efficacious agonists of the human androgen receptor (AR) and induced both the expression of representative AR-regulated genes as well as cellular proliferation in the androgen dependent prostate cancer cell lines, LNCaP and VCaP. Proteomic analysis revealed that 11KDHT regulated the expression of more AR-regulated proteins than DHT in VCaP cells, while in vitro conversion assays showed that 11KT and 11KDHT are metabolized at a significantly lower rate in both LNCaP and VCaP cells when compared to T and DHT, respectively. Our findings show that 11KT and 11KDHT are bona fide androgens capable of inducing androgen-dependant gene expression and cell growth, and that these steroids have the potential to remain active longer than T and DHT due to the decreased rate at which they are metabolised. Collectively, our data demonstrates that 11KT and 11KDHT likely play a vital, but overlooked, role in the development and progression of CRPC. PMID:27442248

  3. Androgen receptor functions in castration-resistant prostate cancer and mechanisms of resistance to new agents targeting the androgen axis

    PubMed Central

    Yuan, X; Cai, C; Chen, S; Chen, S; Yu, Z; Balk, SP

    2016-01-01

    The metabolic functions of androgen receptor (AR) in normal prostate are circumvented in prostate cancer (PCa) to drive tumor growth, and the AR also can acquire new growth-promoting functions during PCa development and progression through genetic and epigenetic mechanisms. Androgen deprivation therapy (ADT, surgical or medical castration) is the standard treatment for metastatic PCa, but patients invariably relapse despite castrate androgen levels (castration-resistant PCa, CRPC). Early studies from many groups had shown that AR was highly expressed and transcriptionally active in CRPC, and indicated that steroids from the adrenal glands were contributing to this AR activity. More recent studies showed that CRPC cells had increased expression of enzymes mediating androgen synthesis from adrenal steroids, and could synthesize androgens de novo from cholesterol. Phase III clinical trials showing a survival advantage in CRPC for treatment with abiraterone (inhibitor of the enzyme CYP17A1 required for androgen synthesis that markedly reduces androgens and precursor steroids) and for enzalutamide (new AR antagonist) have now confirmed that AR activity driven by residual androgens makes a major contribution to CRPC, and led to the recent Food and Drug Administration approval of both agents. Unfortunately, patients treated with these agents for advanced CRPC generally relapse within a year and AR appears to be active in the relapsed tumors, but the molecular mechanisms mediating intrinsic or acquired resistance to these AR-targeted therapies remain to be defined. This review outlines AR functions that contribute to PCa development and progression, the roles of intratumoral androgen synthesis and AR structural alterations in driving AR activity in CRPC, mechanisms of action for abiraterone and enzalutamide, and possible mechanisms of resistance to these agents. PMID:23752196

  4. Prostate Tumor Overexpressed-1 (PTOV1) promotes docetaxel-resistance and survival of castration resistant prostate cancer cells

    PubMed Central

    Cánovas, Verónica; Puñal, Yolanda; Maggio, Valentina; Redondo, Enric; Marín, Mercedes; Mellado, Begoña; Olivan, Mireia; Lleonart, Matilde; Planas, Jacques; Morote, Juan; Paciucci, Rosanna

    2017-01-01

    Metastatic prostate cancer is presently incurable. The oncogenic protein PTOV1, first described in prostate cancer, was reported as overexpressed and significantly correlated with poor survival in numerous tumors. Here, we investigated the role of PTOV1 in prostate cancer survival to docetaxel and self-renewal ability. Transduction of PTOV1 in docetaxel-sensitive Du145 and PC3 cells significantly increased cell survival after docetaxel exposure and induced docetaxel-resistance genes expression (ABCB1, CCNG2 and TUBB2B). In addition, PTOV1 induced prostatospheres formation and self-renewal genes expression (ALDH1A1, LIN28A, MYC and NANOG). In contrast, Du145 and PC3 cells knockdown for PTOV1 significantly accumulated in the G2/M phase, presented a concomitant increased subG1 peak, and cell death by apoptosis. These effects were enhanced in docetaxel-resistant cells. Analyses of tumor datasets show that PTOV1 expression significantly correlated with prostate tumor grade, drug resistance (CCNG2) and self-renewal (ALDH1A1, MYC) markers. These genes are concurrently overexpressed in most metastatic lesions. Metastases also show PTOV1 genomic amplification in significant co-occurrence with docetaxel-resistance and self-renewal genes. Our findings identify PTOV1 as a promoter of docetaxel-resistance and self-renewal characteristics for castration resistant prostate cancer. The concomitant increased expression of PTOV1, ALDH1A1 and CCNG2 in primary tumors, may predict metastasis and bad prognosis. PMID:28938627

  5. Solution formulation development and efficacy of MJC13 in a preclinical model of castration-resistant prostate cancer.

    PubMed

    Liang, Su; Bian, Xiaomei; Liang, Dong; Sivils, Jeffrey C; Neckers, Leonard M; Cox, Marc B; Xie, Huan

    2016-01-01

    MJC13, a novel FKBP52 targeting agent, has potential use for the treatment of castration-resistant prostate cancer. The purpose of this work was to develop a solution formulation of MJC13, and obtain its efficacy profile in a human prostate cancer xenograft mouse model. Preformulation studies were conducted to evaluate the physicochemical properties. Co-solvent systems were evaluated for aqueous solubility and tolerance. A human prostate cancer xenograft mouse model was established by growing 22Rv1 prostate cancer cells in C.B-17 SCID mice. The optimal formulation was used to study the efficacy of MJC13 in this preclinical model of castrate-resistant prostate cancer. We found that MJC13 was stable (at least for 1 month), highly lipophilic (logP = 6.49), poorly soluble in water (0.28 µg/mL), and highly plasma protein bound (>98%). The optimal formulation consisting of PEG 400 and Tween 80 (1:1, v/v) allowed us to achieve a MJC13 concentration of 7.5 mg/mL, and tolerated an aqueous environment. After twice weekly intratumoral injection with 10 mg/kg MJC13 in this formulation for four consecutive weeks, tumor volumes were significantly reduced compared to vehicle-treated controls.

  6. Registered report: the androgen receptor induces a distinct transcriptional program in castration-resistant prostate cancer in man

    PubMed Central

    Chronscinski, Denise; Cherukeri, Srujana; Tan, Fraser; Lomax, Joelle; Iorns, Elizabeth

    2015-01-01

    The Prostate Cancer Foundation-Movember Foundation Reproducibility Initiative (PCFMFRI) seeks to address growing concerns about reproducibility in scientific research by conducting replications of recent papers in the field of prostate cancer. This Registered Report describes the proposed replication plan of key experiments from “The Androgen Receptor Induces a Distinct Transcriptional Program in Castration-Resistant Prostate Cancer in Man” by Sharma and colleagues (2013), published in Cancer Cell in 2013. Of thousands of targets for the androgen receptor (AR), the authors elucidated a subset of 16 core genes that were consistently downregulated with castration and re-emerged with castration resistance. These 16 AR binding sites were distinct from those observed in cells in culture. The authors suggested that cellular context can have dramatic effects on downstream transcriptional regulation of AR binding sites. The present study will attempt to replicate Fig. 7C by comparing gene expression of the 16 core genes identified by Sharma and colleagues in xenograft tumor tissue compared to androgen treated LNCaP cells in vitro. The Prostate Cancer Foundation-Movember Foundation Reproducibility Initiative is a collaboration between the Prostate Cancer Foundation, the Movember Initiative, and Science Exchange, and the results of the replications will be published by PeerJ. PMID:26401447

  7. Budget Impact of Enzalutamide for Chemotherapy-Naïve Metastatic Castration-Resistant Prostate Cancer.

    PubMed

    Bui, Cat N; O'Day, Ken; Flanders, Scott; Oestreicher, Nina; Francis, Peter; Posta, Linda; Popelar, Breanna; Tang, Hong; Balk, Mark

    2016-02-01

    Prostate cancer is expected to account for approximately one quarter of all new diagnoses of cancer in American men in 2015. The cost of prostate cancer care is expected to reach $15.1 billion by the year 2020, up from $11.9 billion in 2010. Given the high burden of prostate cancer, health care payers are interested in quantifying the potential budget impact of new therapies. To estimate the budget impact of enzalutamide for the treatment of chemotherapy-naïve metastatic castration-resistant prostate cancer (mCRPC) from a U.S. payer perspective. A model was developed to assess the budget impact of enzalutamide for treatment of chemotherapy-naïve mCRPC patients in a hypothetical 1-million-member U.S. health plan over a 1-year time horizon. Comparators included abiraterone acetate, sipuleucel-T, radium Ra 223 dichloride, and docetaxel. Epidemiologic data, including National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) incidence rates, were used to estimate the number of chemotherapy-naïve mCRPC patients. Dosing, administration, duration of therapy, and adverse event rates were based on package inserts and pivotal studies. Drug costs were obtained from RED BOOK and Centers for Medicare & Medicaid Services (CMS) average sales price pricing files, costs of administration and monitoring from the CMS physician fee schedule, and adverse events from the Agency for Healthcare Research and Quality Healthcare Cost and Utilization Project and published literature. Market shares were estimated for each comparator before and after adoption of enzalutamide. The incremental aggregate budget impact, per patient per year (PPPY), per patient per month (PPPM), and per member per month (PMPM), was calculated. One-way sensitivity analyses were performed. In a population of 115 chemotherapy-naïve mCRPC patients, adopting enzalutamide had an annual incremental budget impact of $510,641 ($4,426 PPPY, $369 PPPM, and $0.04 PMPM). Results were most sensitive to

  8. Methylselenol prodrug enhances MDV3100 efficacy for treatment of castration-resistant prostate cancer.

    PubMed

    Zhan, Yang; Cao, Bo; Qi, Yanfeng; Liu, Shuang; Zhang, Qi; Zhou, Weidong; Xu, Duo; Lu, Hua; Sartor, Oliver; Kong, Wei; Zhang, Haitao; Dong, Yan

    2013-11-01

    The next-generation antiandrogen MDV3100 prolongs overall survival of patients with metastatic castration-resistant prostate cancer (CRPC). However, patient responses are variable, and survival benefit remains relatively small. Developing effective modality to improve MDV3100 efficacy is urgently needed. Recent evidence suggests that constitutively active androgen receptor splice variants (AR-Vs) drive resistance to MDV3100. In our study, we show that methylselenol prodrug downregulates the expression and activity of both the full-length AR (AR-FL) and AR-Vs. The downregulation is independent of androgen and could be attributable to repressed transcription of the AR gene. Cotreatment with methylselenol prodrug and MDV3100 suppresses AR signaling more dramatically than either agent alone, and synergistically inhibits the growth of CRPC cells in vitro. The combinatorial efficacy is observed in not only AR-V-expressing cells but also cells expressing predominantly AR-FL, likely owing to the ability of the two drugs to block the AR signaling cascade at distinct steps. Ectopic expression of AR-FL or AR-V7 attenuates the combinatorial efficacy, indicating that downregulating AR-FL and AR-V7 is importantly involved in mediating the combinatorial efficacy. Significantly, methylselenol prodrug also downregulates AR-FL and AR-Vs in vivo and substantially improves the antitumor efficacy of MDV3100. These findings support a potential combination therapy for improving MDV3100 efficacy, and provide a rationale for evaluating the clinical application of combining methylselenol prodrug with MDV3100 for the treatment of CRPC. © 2013 UICC.

  9. Methylselenol prodrug enhances MDV3100 efficacy for treatment of castration-resistant prostate cancer

    PubMed Central

    Zhan, Yang; Cao, Bo; Qi, Yanfeng; Liu, Shuang; Zhang, Qi; Zhou, Weidong; Xu, Duo; Lu, Hua; Sartor, Oliver; Kong, Wei; Zhang, Haitao; Dong, Yan

    2013-01-01

    The next-generation antiandrogen MDV3100 prolongs overall survival of patients with metastatic castration-resistant prostate cancer (CRPC). However, patient responses are variable, and survival benefit remains relatively small. Developing effective modality to improve MDV3100 efficacy is urgently needed. Recent evidence suggests that constitutively active androgen receptor splice variants (AR-Vs) drive resistance to MDV3100. In our study, we show that methylselenol prodrug downregulates the expression and activity of both the full-length AR (AR-FL) and AR-Vs. The downregulation is independent of androgen and could be attributable to repressed transcription of the AR gene. Cotreatment with methylselenol prodrug and MDV3100 suppresses AR signaling more dramatically than either agent alone, and synergistically inhibits the growth of CRPC cells in vitro. The combinatorial efficacy is observed in not only AR-V-expressing cells but also cells expressing predominantly AR-FL, likely owing to the ability of the two drugs to block the AR signaling cascade at distinct steps. Ectopic expression of AR-FL or AR-V7 attenuates the combinatorial efficacy, indicating that downregulating AR-FL and AR-V7 is importantly involved in mediating the combinatorial efficacy. Significantly, methylselenol prodrug also downregulates AR-FL and AR-Vs in vivo and substantially improves the antitumor efficacy of MDV3100. These findings support a potential combination therapy for improving MDV3100 efficacy, and provide a rationale for evaluating the clinical application of combining methylselenol prodrug with MDV3100 for the treatment of CRPC. PMID:23575870

  10. Curcumin induces apoptosis and protective autophagy in castration-resistant prostate cancer cells through iron chelation.

    PubMed

    Yang, Chunguang; Ma, Xueyou; Wang, Zhihua; Zeng, Xing; Hu, Zhiquan; Ye, Zhangqun; Shen, Guanxin

    2017-01-01

    Curcumin induces apoptosis and autophagy in different cancer cells. Moreover, chemical and biological experiments have evidenced that curcumin is a biologically active iron chelator and induces cytotoxicity through iron chelation. We thus hypothesized that curcumin may induce apoptosis and autophagy in castration-resistant prostate cancer (CRPC) cells through its iron-chelating properties. CRPC cells were loaded with curcumin alone or in combination with ferric ammonium citrate (FAC). Cytotoxicity was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was assessed by flow cytometry, terminal deoxynucleotidyl transferase nick end labeling (TUNEL) assay and caspase activity. Autophagy status was analyzed by the detection of autophagosomes and light chain 3-II (LC3-II) using transmission electron microscopy and Western blot. Iron-binding activity of curcumin was assessed by spectrophotometry and MTT assay. The expression levels of transferrin receptor 1 (TfR1) and iron regulatory protein 1 (IRP1) were examined by Western blot. Curcumin induced apoptosis and autophagy in CRPC cells. Combining curcumin with autophagy inhibitors (3-methyladenine [3-MA]) synergized the apoptotic effect of curcumin. Moreover, curcumin bound to FAC at a ratio of ~1:1, as assessed by spectrophotometry and MTT assay. Apoptosis and autophagy induced by curcumin were counteracted by equal amounts of FAC. At apoptosis- and autophagy-inducing concentrations, curcumin enhanced the expression levels of TfR1 and IRP1, indicative of iron deprivation induced by curcumin. Together, our results indicate that curcumin induces apoptosis and protective autophagy in CRPC cells, which are at least partially dependent on its iron-chelating properties.

  11. INITIAL EXPERIENCE OF THE ENZALUTAMIDE TREATMENT FOR CASTRATION-RESISTANT PROSTATE CANCER.

    PubMed

    Igarashi, Atsushi; Fukagai, Takashi; Morita, Masashi; Hayashi, Keiichiro; Koshikiya, Atsushi; Ogawa, Yoshio; Fuji, Kohzo; Naoe, Michio; Morita, Jun; Oshinomi, Kazuhiko; Nakazato, Takehiko; Ogawa, Yu; Matsui, Yuki; Shimada, Makoto; Inoue, Katsuki; Saito, Katsuyuki; Ogawa, Yuichiro; Matsumoto, Yuki; Sasaki, Haruaki; Ota, Michiya; Yamamoto, Kenro; Shimoyama, Hideaki; Imamura, Yuichiro; Yamagishi, Motoki; Tanifuji, Satoru; Ishihara, Masahiro; Shichijyo, Takeshi; Sato, Naoya; Omori, Kei; Matsubara, Eiji

    2016-01-01

    (Objective) Enzalutamide is an oral androgen-receptor inhibitor that prolongs survival in men with castration-resistant prostate cancer (CRPC). We retrospectively evaluated clinical efficacy and safety of enzalutamide in CRPC. (Patients and methods) We reviewed clinical records of 73 patients who had received enzalutamide for the CRPC at Showa University and affiliated 7 hospitals. Enzalutamide was given at a dose of 160 mg/day, but some patients were treated at lower dose because of there age or poor performance status. Prostrate-specific antigen (PSA) response, prior docetaxel use and the previously administered agents were evaluated retrospectively. (Results) The median patients age was 77 years, the median Gleason score was 9 and the median PSA level at baseline was 26.9 ng/ml. The patients who had prior docetaxel use were 29 (39.7%) and the median of total docetaxel dose was 460 mg/body. The median number of total prior treatments (anti-androgens, Estramustine and steroid) was 3. Twenty seven (61.4%) patients with docetaxel-naïve achieved over 50% reduction of PSA level from baseline, but only 7 (24.1%) in patients previously treated with docetaxel. The most common adverse events included fatigue (24.7%), anorexia (24.7%) and the nausea (16.4%). We found a small proportion of responders to enzalutamide experienced a PSA flare. (Conclusion) Our results of the use of Enzaltamide for CRPC were similar with previous reports. PSA flare was found in some patients with CRPC who responded to enzaltamide. It should be noted that this possible PSA flare phenomenon.

  12. Identification of docetaxel resistance genes in castration-resistant prostate cancer.

    PubMed

    Marín-Aguilera, Mercedes; Codony-Servat, Jordi; Kalko, Susana G; Fernández, Pedro L; Bermudo, Raquel; Buxo, Elvira; Ribal, María José; Gascón, Pedro; Mellado, Begoña

    2012-02-01

    Docetaxel-based chemotherapy is the standard first-line therapy in metastatic castration-resistant prostate cancer (CRPC). However, most patients eventually develop resistance to this treatment. In this study, we aimed to identify key molecular genes and networks associated with docetaxel resistance in two models of docetaxel-resistant CRPC cell lines and to test for the most differentially expressed genes in tumor samples from patients with CRPC. DU-145 and PC-3 cells were converted to docetaxel-resistant cells, DU-145R and PC-3R, respectively. Whole-genome arrays were used to compare global gene expression between these four cell lines. Results showed differential expression of 243 genes (P < 0.05, Bonferroni-adjusted P values and log ratio > 1.2) that were common to DU-145R and PC-3R cells. These genes were involved in cell processes like growth, development, death, proliferation, movement, and gene expression. Genes and networks commonly deregulated in both DU-145R and PC-3R cells were studied by Ingenuity Pathways Analysis. Exposing parental cells to TGFB1 increased their survival in the presence of docetaxel, suggesting a role of the TGF-β superfamily in conferring drug resistance. Changes in expression of 18 selected genes were validated by real-time quantitative reverse transcriptase PCR in all four cell lines and tested in a set of 11 FFPE and five optimal cutting temperature tumor samples. Analysis in patients showed a noteworthy downexpression of CDH1 and IFIH1, among others, in docetaxel-resistant tumors. This exploratory analysis provides information about potential gene and network involvement in docetaxel resistance in CRPC. Further clinical validation of these results is needed to develop targeted therapies in patients with CRPC that can circumvent such resistance to treatment.

  13. Curcumin induces apoptosis and protective autophagy in castration-resistant prostate cancer cells through iron chelation

    PubMed Central

    Yang, Chunguang; Ma, Xueyou; Wang, Zhihua; Zeng, Xing; Hu, Zhiquan; Ye, Zhangqun; Shen, Guanxin

    2017-01-01

    Background Curcumin induces apoptosis and autophagy in different cancer cells. Moreover, chemical and biological experiments have evidenced that curcumin is a biologically active iron chelator and induces cytotoxicity through iron chelation. We thus hypothesized that curcumin may induce apoptosis and autophagy in castration-resistant prostate cancer (CRPC) cells through its iron-chelating properties. Materials and methods CRPC cells were loaded with curcumin alone or in combination with ferric ammonium citrate (FAC). Cytotoxicity was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was assessed by flow cytometry, terminal deoxynucleotidyl transferase nick end labeling (TUNEL) assay and caspase activity. Autophagy status was analyzed by the detection of autophagosomes and light chain 3-II (LC3-II) using transmission electron microscopy and Western blot. Iron-binding activity of curcumin was assessed by spectrophotometry and MTT assay. The expression levels of transferrin receptor 1 (TfR1) and iron regulatory protein 1 (IRP1) were examined by Western blot. Results Curcumin induced apoptosis and autophagy in CRPC cells. Combining curcumin with autophagy inhibitors (3-methyladenine [3-MA]) synergized the apoptotic effect of curcumin. Moreover, curcumin bound to FAC at a ratio of ~1:1, as assessed by spectrophotometry and MTT assay. Apoptosis and autophagy induced by curcumin were counteracted by equal amounts of FAC. At apoptosis- and autophagy-inducing concentrations, curcumin enhanced the expression levels of TfR1 and IRP1, indicative of iron deprivation induced by curcumin. Conclusion Together, our results indicate that curcumin induces apoptosis and protective autophagy in CRPC cells, which are at least partially dependent on its iron-chelating properties. PMID:28243065

  14. Midkine is associated with neuroendocrine differentiation in castration-resistant prostate cancer.

    PubMed

    Nordin, Anna; Wang, Wanzhong; Welén, Karin; Damber, Jan-Erik

    2013-05-01

    Castration-resistant prostate cancer (CRPC) is an incurable disease and both androgen-deprivation therapy (ADT) and neuroendocrine differentiation (NED) are closely related to CRPC transition. More knowledge concerning neuroendocrine (NE)-transformed PC cells, the NED process and its association with CRPC, is needed. Expression of growth factor midkine (MDK) is correlated with poor clinical outcomes in various human cancers, including PC. In the present study, we have evaluated MDK expression and NED in two separate tumor groups: early and advanced PC. Immunohistochemical analysis of MDK, the neuronal marker tubulin-beta III (TUBB3) and the NE-marker chromogranin A (CGA) in a human archival material consisting of hormone naive (HN)/stage T1b (n = 29) and CRPC (n = 24) tumors. Triple immunofluorescent imaging was performed on a selection of specimens. MDK, TUBB3, and CGA were upregulated in CRPC compared to HN tumors. MDK was highly associated to the expression of both CGA and TUBB3, and identified MDK-positive NE-like looking cells found to co-express CGA or, more commonly, CGA together with TUBB3. CGA and TUBB3 staining displayed a partial expression overlap, an overlap almost exclusively displaying also MDK expression. MDK upregulation in CRPC is associated with NED (shown by its relation to CGA and TUBB3). The results suggest that MDK represents an over-bridging marker between different populations of NE-like tumor cells, possibly as part of the NED process and associated CRPC transition, something that needs to be evaluated experimentally as does the applicability of MDK as a future target. Copyright © 2012 Wiley Periodicals, Inc.

  15. Use of prednisone with abiraterone acetate in metastatic castration-resistant prostate cancer.

    PubMed

    Auchus, Richard J; Yu, Margaret K; Nguyen, Suzanne; Mundle, Suneel D

    2014-12-01

    Abiraterone acetate, a prodrug of the CYP17A1 inhibitor abiraterone that blocks androgen biosynthesis, is approved for treatment of patients with metastatic castration-resistant prostate cancer (mCRPC) in combination with prednisone or prednisolone 5 mg twice daily. This review evaluates the basis for the effects of prednisone on mineralocorticoid-related adverse events that arise because of CYP17A1 inhibition with abiraterone. Coadministration with the recommended dose of glucocorticoid compensates for abiraterone-induced reductions in serum cortisol and blocks the compensatory increase in adrenocorticotropic hormone seen with abiraterone. Consequently, 5 mg prednisone twice daily serves as a glucocorticoid replacement therapy when coadministered with abiraterone acetate, analogous to use of glucocorticoid replacement therapy for certain endocrine disorders. We searched PubMed to identify safety concerns regarding glucocorticoid use, placing a focus on longitudinal studies in autoimmune and inflammatory diseases and cancer. In general, glucocorticoid-related adverse events, including bone loss, immunosuppression, hyperglycemia, mood and cognitive alterations, and myopathy, appear dose related and tend to occur at doses and/or treatment durations greater than the low dose of glucocorticoid approved in combination with abiraterone acetate for the treatment of mCRPC. Although glucocorticoids are often used to manage tumor-related symptoms or to prevent treatment-related toxicity, available evidence suggests that prednisone and dexamethasone might also offer modest therapeutic benefit in mCRPC. Given recent improvements in survival achieved for mCRPC with novel agents in combination with prednisone, the risks of these recommended glucocorticoid doses must be balanced with the benefits shown for these regimens.

  16. Phase I Study of ARN-509, a Novel Antiandrogen, in the Treatment of Castration-Resistant Prostate Cancer

    PubMed Central

    Rathkopf, Dana E.; Morris, Michael J.; Fox, Josef J.; Danila, Daniel C.; Slovin, Susan F.; Hager, Jeffrey H.; Rix, Peter J.; Chow Maneval, Edna; Chen, Isan; Gönen, Mithat; Fleisher, Martin; Larson, Steven M.; Sawyers, Charles L.; Scher, Howard I.

    2013-01-01

    Purpose ARN-509 is a novel androgen receptor (AR) antagonist for the treatment of castration-resistant prostate cancer (CRPC). ARN-509 inhibits AR nuclear translocation and AR binding to androgen response elements and, unlike bicalutamide, does not exhibit agonist properties in the context of AR overexpression. This first-in-human phase I study assessed safety, tolerability, pharmacokinetics, pharmacodynamics, and antitumor activity of ARN-509 in men with metastatic CRPC. Patients and Methods Thirty patients with progressive CRPC received continuous daily oral ARN-509 at doses between 30 and 480 mg, preceded by administration of a single dose followed by a 1-week observation period with pharmacokinetic sampling. Positron emission tomography/computed tomography imaging was conducted to monitor [18F]fluoro-α-dihydrotestosterone (FDHT) binding to AR in tumors before and during treatment. Primary objective was to determine pharmacokinetics, safety, and recommended phase II dose. Results Pharmacokinetics were linear and dose proportional. Prostate-specific antigen declines at 12 weeks (≥ 50% reduction from baseline) were observed in 46.7% of patients. Reduction in FDHT uptake was observed at all doses, with a plateau in response at ≥ 120-mg dose, consistent with saturation of AR binding. The most frequently reported adverse event was grade 1/2 fatigue (47%). One dose-limiting toxicity event (grade 3 abdominal pain) occurred at the 300-mg dose. Dose escalation to 480 mg did not identify a maximum-tolerated dose. Conclusion ARN-509 was safe and well tolerated, displayed dose-proportional pharmacokinetics, and demonstrated pharmacodynamic and antitumor activity across all dose levels tested. A maximum efficacious dose of 240 mg daily was selected for phase II exploration based on integration of preclinical and clinical data. PMID:24002508

  17. Phase I study of ARN-509, a novel antiandrogen, in the treatment of castration-resistant prostate cancer.

    PubMed

    Rathkopf, Dana E; Morris, Michael J; Fox, Josef J; Danila, Daniel C; Slovin, Susan F; Hager, Jeffrey H; Rix, Peter J; Chow Maneval, Edna; Chen, Isan; Gönen, Mithat; Fleisher, Martin; Larson, Steven M; Sawyers, Charles L; Scher, Howard I

    2013-10-01

    ARN-509 is a novel androgen receptor (AR) antagonist for the treatment of castration-resistant prostate cancer (CRPC). ARN-509 inhibits AR nuclear translocation and AR binding to androgen response elements and, unlike bicalutamide, does not exhibit agonist properties in the context of AR overexpression. This first-in-human phase I study assessed safety, tolerability, pharmacokinetics, pharmacodynamics, and antitumor activity of ARN-509 in men with metastatic CRPC. Thirty patients with progressive CRPC received continuous daily oral ARN-509 at doses between 30 and 480 mg, preceded by administration of a single dose followed by a 1-week observation period with pharmacokinetic sampling. Positron emission tomography/computed tomography imaging was conducted to monitor [(18)F]fluoro-α-dihydrotestosterone (FDHT) binding to AR in tumors before and during treatment. Primary objective was to determine pharmacokinetics, safety, and recommended phase II dose. Pharmacokinetics were linear and dose proportional. Prostate-specific antigen declines at 12 weeks (≥ 50% reduction from baseline) were observed in 46.7% of patients. Reduction in FDHT uptake was observed at all doses, with a plateau in response at ≥ 120-mg dose, consistent with saturation of AR binding. The most frequently reported adverse event was grade 1/2 fatigue (47%). One dose-limiting toxicity event (grade 3 abdominal pain) occurred at the 300-mg dose. Dose escalation to 480 mg did not identify a maximum-tolerated dose. ARN-509 was safe and well tolerated, displayed dose-proportional pharmacokinetics, and demonstrated pharmacodynamic and antitumor activity across all dose levels tested. A maximum efficacious dose of 240 mg daily was selected for phase II exploration based on integration of preclinical and clinical data.

  18. Concurrent Androgen and Estrogen Ablation and Inhibition of Steroid Biosynthetic Enzyme Treatment for Castration-resistant Prostate Cancer.

    PubMed

    Sinha, Akhouri A; Pomroy, Francis E; Wilson, Michael J

    2016-08-01

    About 80 to 90% of prostate cancer (PCa) is androgen-dependent at diagnosis, but patients ultimately develop castration-resistant prostate cancer (CRPC), which is usually not amenable to androgen deprivation (ablation) therapy (ADT). Patients with CRPC usually succumb to death in less than 5 years and there is no cure. Here, we investigated reasons for ADT failure. Biopsy specimens from untreated and diethylstilbestrol (DES)-treated patients were assessed for localization of antibody IgGs against androgen (AR) and estrogen (ER) receptors. In untreated and DES-treated sections, methylene blue stained basic proteins in dark basal (undifferentiated) PCa cells, whereas light basal cells were not stained. AR localized to light basal cells which showed widespread degeneration in sections from DES-treated patients, indicating their dependence on androgen. In contrast, dark basal cells did not show widespread degeneration in DES-treated patients; ER was usually localized in dark cells. The number of dark cells progressively increased in DES-treated patients indicating their androgen-independence. The localization of AR and ER in some light and dark basal cells indicated that the supply of androgen/estrogen was not inhibited during ADT. Dark basal cells had emerged prior to treatment and proliferated during DES treatment, that also indicated their androgen-independence. PCa has at least two populations of cells: androgen-dependent light basal and estrogen-dependent dark basal cells. ADT did not destroy estrogen-dependent cells which may have given rise to CRPC tumors. Therefore, ADT is an incomplete treatment. For a more complete treatment of PCa, we recommend concurrent androgen and estrogen ablation, together with the inhibition of selected steroid biosynthetic enzymes. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  19. Influence of Statins on Survival Outcome in Patients with Metastatic Castration Resistant Prostate Cancer Treated with Abiraterone Acetate

    PubMed Central

    Boegemann, Martin; Schlack, Katrin; Fischer, Ann-Kathrin; Gerß, Joachim; Steinestel, Julie; Semjonow, Axel; Schrader, Andres Jan; Krabbe, Laura-Maria

    2016-01-01

    Objective Even though the exact mechanism is largely unknown until now, statins are supposed to improve survival outcomes in various malignancies. For prostate cancer however, statins are known to compete with dehydroepiandrosterone (DHEAS) for the transport into the cytosol both using the cell by the Solute Carrier Transporter and thus diminish the cellular uptake of DHEAS as a precursor of androgens. Abiraterone inhibits CYP17A1 and thus effectively decreases the production of all relevant androgens including DHEAS. In this study we examined whether statins still affect survival outcome in patients with metastatic castration resistant prostate cancer (mCRPC) when treated with Abiraterone. Patients and Methods 108 men with mCRPC treated with Abiraterone from 02/2010 to 07/2015 with (n = 21) or without (n = 87) concomitant treatment with statins were investigated. Progression free survival (PFS) and overall survival (OS) were analyzed using Kaplan-Meier-estimates and univariate Cox-regression analysis. The influence on best clinical benefit under Abiraterone treatment was analyzed with bivariate and multivariate logistic regression analysis. Results PSA-decline ≥ 50% was not significantly different in both groups (57 vs. 53%; p = 0.73). The median PFS (9 vs. 10 months; p = 0.97) and OS (14 vs. 18 months; p = 0.77) did not differ significantly between those men treated with and without concomitant statin therapy, respectively. Accordingly, there was no improvement for best clinical benefit in patients using statins (odds ratio: 1.2 (CI: 0.4–4.2); p = 0.76). Conclusion Use of statins as concomitant medication did not improve survival outcomes or best clinical benefit in men with mCRPC treated with Abiraterone. PMID:27583544

  20. Docetaxel with or without estramustine for estramustine refractory castration-resistant prostate cancer: a single institution experience

    PubMed Central

    2012-01-01

    Background The significance of combination of docetaxel (DTX) with estramustine phosphate (EMP) in castration-resistant prostate cancer (CRPC) patients remains unclear. In this study, we aimed to retrospectively evaluate the efficacy and toxicity of DTX with or without EMP and to elucidate the significance of DTX and EMP combination therapy in Japanese EMP-refractory CRPC patients. Methods To compare the efficacy and toxicity of DTX and EMP, we divided CRPC patients, who were confirmed to be resistant to EMP, into the following two groups: group D (n = 28), which included patients treated with DTX (60 mg/m2, once in every four weeks) alone, and group DE (n = 33), which included patients treated with a combination of DTX (60 mg/m2, once in every four weeks) and EMP (twice daily oral administration at 280 mg). Results Prostate specific antigen (PSA) response (> 50% decline in PSA) was observed in six patients (21%) in group D and eight patients (24%) in group DE. The median time to progression (TTP) was 12.0 months and 6.2 months and the median overall survival (OS) was 26.4 months and 24.3 months in group D and DE, respectively. There was no statistical difference between the two groups in terms of PSA response, TTP, and OS. The incidence of adverse events of grade 3/4 was low in both the groups, and there was no statistical difference between the two groups. Conclusions Although treatment with DTX at 60 mg/m2 was effective and highly tolerated in EMP-refractory Japanese CRPC patients, the DTX and EMP combination therapy might not exhibit any survival benefit for CRPC patients. PMID:22353627

  1. Docetaxel with or without estramustine for estramustine refractory castration-resistant prostate cancer: a single institution experience.

    PubMed

    Nakano, Kazuhiko; Ohta, Shigeyuki; Komatsu, Kenji; Kubo, Taro; Nukui, Akinori; Suzuki, Kazumi; Kurokawa, Shinsuke; Kobayashi, Minoru; Morita, Tatsuo

    2012-02-22

    The significance of combination of docetaxel (DTX) with estramustine phosphate (EMP) in castration-resistant prostate cancer (CRPC) patients remains unclear. In this study, we aimed to retrospectively evaluate the efficacy and toxicity of DTX with or without EMP and to elucidate the significance of DTX and EMP combination therapy in Japanese EMP-refractory CRPC patients. To compare the efficacy and toxicity of DTX and EMP, we divided CRPC patients, who were confirmed to be resistant to EMP, into the following two groups: group D (n = 28), which included patients treated with DTX (60 mg/m2, once in every four weeks) alone, and group DE (n = 33), which included patients treated with a combination of DTX (60 mg/m2, once in every four weeks) and EMP (twice daily oral administration at 280 mg). Prostate specific antigen (PSA) response (> 50% decline in PSA) was observed in six patients (21%) in group D and eight patients (24%) in group DE. The median time to progression (TTP) was 12.0 months and 6.2 months and the median overall survival (OS) was 26.4 months and 24.3 months in group D and DE, respectively. There was no statistical difference between the two groups in terms of PSA response, TTP, and OS. The incidence of adverse events of grade 3/4 was low in both the groups, and there was no statistical difference between the two groups. Although treatment with DTX at 60 mg/m2 was effective and highly tolerated in EMP-refractory Japanese CRPC patients, the DTX and EMP combination therapy might not exhibit any survival benefit for CRPC patients.

  2. Circulating AR copy number and outcome to enzalutamide in docetaxel-treated metastatic castration-resistant prostate cancer.

    PubMed

    Salvi, Samanta; Casadio, Valentina; Conteduca, Vincenza; Lolli, Cristian; Gurioli, Giorgia; Martignano, Filippo; Schepisi, Giuseppe; Testoni, Sara; Scarpi, Emanuela; Amadori, Dino; Calistri, Daniele; Attard, Gerhardt; De Giorgi, Ugo

    2016-06-21

    In the present study, we aimed to evaluate the association of circulating AR copy number (CN) and outcome in a cohort of patients with advanced castration-resistant prostate cancer (CRPC) treated with enzalutamide after docetaxel. Fifty-nine CRPC patients were evaluated. AR CN was analyzed with real-time and digital PCR in the serum collected at starting of treatment. Progressive disease was defined on the basis of Prostate Cancer Working Group 2 criteria. AR CN gain was found in 21 of 59 (36%) patients. Median baseline PSA, alkaline phosphatase and lactate dehydrogenase levels were higher in the AR CN gained group (p = 0.007, p = 0.003, p = 0.0009, respectively). Median PFS of patients with AR CN gain was 2.4 (95%CI: 1.9-3.2) vs. 4.0 months (95%CI: 3.0-6.5) of those with no gain (p = 0.0004). Median OS of patients with AR CN gain was 6.1 (95%CI: 3.4-8.6) vs. 14.1 months (95%CI: 8.2-20.5) of those with no gain (p = 0.0003). At multivariate analysis, PSA decline ≥ 50% and AR CN showed a significant association with PFS (p = 0.008 and p = 0.002, respectively) and OS (p = 0.009 and p = 0.001, respectively). These findings indicate that the detection of circulating AR CN gain is a promising non-invasive biomarker for outcome prediction to enzalutamide treatment in CRPC patients.

  3. Phase-1 study of abiraterone acetate in chemotherapy-naïve Japanese patients with castration-resistant prostate cancer.

    PubMed

    Matsubara, Nobuaki; Uemura, Hiroji; Fukui, Iwao; Niwakawa, Masashi; Yamaguchi, Akito; Iizuka, Koho; Akaza, Hideyuki

    2014-10-01

    Persistent androgen synthesis under castration status in adrenal gland, testes and tumor cells is thought to be one of the major causes of development and progression of castration-resistant prostate cancer (CRPC). Abiraterone acetate (AA), the prodrug of abiraterone, which is an inhibitor of androgen synthesis enzymes, was evaluated for pharmacokinetics, pharmacodynamics, preliminary efficacy and safety in Japanese patients with CRPC in a phase-1, open-label and dose-escalation study. Chemotherapy-naïve Japanese CRPC patients (N = 27) received one of four AA daily doses (250 mg [n = 9], 500 mg [n = 6], 1000 [1 h premeal] mg [n = 6] and 1000 [2 h postmeal] mg [n = 6]) continuously through 28-day treatment cycles. In the first cycle, AA monotherapy was given on days 1-7 for pharmacokinetics, and AA plus prednisone (5 mg twice daily) from days 8 to 28. Of 27 patients, 9 continued treatment with AA until the data cut-off date (18 July 2013). Over the evaluated dose range, plasma abiraterone concentrations increased with dose, with median tmax 2-3 h. At each dose level, mean serum corticosterone concentrations increased, while testosterone and dehydroepiandrosterone sulfate concentrations rapidly decreased following a single AA dose and were further reduced to near the quantification limit on day 8 regardless of the dose. At least 3 patients from each dose-group experienced ≥50% prostate-specific antigen reduction, suggesting clinical benefit from AA in Japanese CRPC patients. AA was generally well-tolerated, and, therefore, the recommended AA dosage regimen in Japanese CRPC patients is 1000 mg oral dose under modified fasting conditions (at least 1 h premeal or 2 h postmeal). This study is registered at ClinicalTrials.gov: NCT01186484.

  4. Androgen receptor-mediated downregulation of microRNA-221 and -222 in castration-resistant prostate cancer

    PubMed Central

    Gui, Bin; Hsieh, Chen-Lin; Kantoff, Philip W.; Kibel, Adam S.

    2017-01-01

    MicroRNAs (miRNAs) play important roles in cancer formation and progression by suppressing the production of key functional proteins at the post-transcriptional level in a sequence-specific manner. While differential expression of miRNAs is widely observed in cancers including prostate cancer (PCa), how these miRNAs are transcriptionally regulated is largely unknown. MiRNA-221 and miRNA-222 (miR-221/-222) are well-established oncogenes and overexpressed in breast, liver, pancreas, and lung cancer, but their expression and biological functions in PCa remain controversial. Both up and down regulation have been observed in patient samples. Specifically, studies have demonstrated miR-221/-222 function as oncogenes, and promote PCa cell proliferation and the development of castration-resistant prostate cancer (CRPC). However, the expression level of miR-221/-222 is downregulated in several miRNA expression profiling studies. In this study, we demonstrate miR-221/-222 are androgen receptor (AR)-repressed genes and reside in a long primary transcript (pri-miRNA). Derepression of miR-221/-222 after androgen deprivation therapy (ADT) may enhance PCa cell proliferation potential through promoting G1/S phase transition. This function is likely transient but important in the development of CRPC. Downregulation of miR-221/-222 subsequently occurs once AR activity is restored through AR overexpression in CRPC. Our findings shed light on the complexity of transcriptional regulation of miRNAs in PCa and suggest context-dependent targeting of oncogenic miRNAs. PMID:28886115

  5. Synergistic simvastatin and metformin combination chemotherapy for osseous metastatic castration-resistant prostate cancer.

    PubMed

    Babcook, Melissa A; Shukla, Sanjeev; Fu, Pingfu; Vazquez, Edwin J; Puchowicz, Michelle A; Molter, Joseph P; Oak, Christine Z; MacLennan, Gregory T; Flask, Chris A; Lindner, Daniel J; Parker, Yvonne; Daneshgari, Firouz; Gupta, Sanjay

    2014-10-01

    Docetaxel chemotherapy remains a standard of care for metastatic castration-resistant prostate cancer (CRPC). Docetaxel modestly increases survival, yet results in frequent occurrence of side effects and resistant disease. An alternate chemotherapy with greater efficacy and minimal side effects is needed. Acquisition of metabolic aberrations promoting increased survival and metastasis in CRPC cells includes constitutive activation of Akt, loss of adenosine monophosphate-activated protein kinase (AMPK) activity due to Ser-485/491 phosphorylation, and overexpression of 3-hydroxy-3-methylglutaryl-Coenzyme A reductase (HMG-CoAR). We report that combination of simvastatin and metformin, within pharmacologic dose range (500 nmol/L to 4 μmol/L simvastatin and 250 μmol/L to 2 mmol/L metformin), significantly and synergistically reduces C4-2B3/B4 CRPC cell viability and metastatic properties, with minimal adverse effects on normal prostate epithelial cells. Combination of simvastatin and metformin decreased Akt Ser-473 and Thr-308 phosphorylation and AMPKα Ser-485/491 phosphorylation; increased Thr-172 phosphorylation and AMPKα activity, as assessed by increased Ser-79 and Ser-872 phosphorylation of acetyl-CoA carboxylase and HMG-CoAR, respectively; decreased HMG-CoAR activity; and reduced total cellular cholesterol and its synthesis in both cell lines. Studies of C4-2B4 orthotopic NCr-nu/nu mice further demonstrated that combination of simvastatin and metformin (3.5-7.0 μg/g body weight simvastatin and 175-350 μg/g body weight metformin) daily by oral gavage over a 9-week period significantly inhibited primary ventral prostate tumor formation, cachexia, bone metastasis, and biochemical failure more effectively than 24 μg/g body weight docetaxel intraperitoneally injected every 3 weeks, 7.0 μg/g/day simvastatin, or 350 μg/g/day metformin treatment alone, with significantly less toxicity and mortality than docetaxel, establishing combination of simvastatin and

  6. Synergistic Simvastatin and Metformin Combination Chemotherapy for Osseous Metastatic Castration-Resistant Prostate Cancer

    PubMed Central

    Babcook, Melissa A.; Shukla, Sanjeev; Fu, Pingfu; Vazquez, Edwin J.; Puchowicz, Michelle A.; Molter, Joseph P.; Oak, Christine Z.; MacLennan, Gregory T.; Flask, Chris A.; Lindner, Daniel J.; Parker, Yvonne; Daneshgari, Firouz; Gupta, Sanjay

    2014-01-01

    Docetaxel (DTX) chemotherapy remains a standard-of-care for metastatic castration-resistant prostate cancer (CRPC). DTX modestly increases survival, yet results in frequent occurrence of side-effects and resistant disease. An alternate chemotherapy with greater efficacy and minimal side-effects is needed. Acquisition of metabolic aberrations promoting increased survival and metastasis in CRPC cells include constitutive activation of Akt, loss of adenosine monophosphate-activated protein kinase (AMPK) activity due to Ser-485/491 phosphorylation, and over-expression of 3-hydroxy-3-methylglutaryl-Coenzyme A reductase (HMG-CoAR). We report that combination of simvastatin (SIM) and metformin (MET), within pharmacological dose range (500nM to 4µM SIM and 250µM to 2mM MET), significantly and synergistically reduces C4-2B3/B4 CRPC cell viability and metastatic properties with minimal adverse effects on normal prostate epithelial cells. Combination of SIM and MET decreased Akt Ser-473 and Thr-308 phosphorylation and AMPKα Ser-485/491 phosphorylation, increased Thr-172 phosphorylation and AMPKα activity as assessed by increased Ser-79 and Ser-872 phosphorylation of acetyl-CoA carboxylase and HMG-CoAR, respectively; decreased HMG-CoAR activity, and reduced total cellular cholesterol and its synthesis in both cell lines. Studies of C4-2B4 orthotopic NCr-nu/nu mice further demonstrated that combination of SIM and MET (3.5–7.0µg/g body weight SIM and 175–350µg/g body weight MET) daily by oral gavage over 9-week period significantly inhibited primary ventral prostate tumor formation, cachexia, bone metastasis, and biochemical failure more effectively than 24µg/g body weight DTX intraperitoneally-injected every three weeks, 7.0µg/g/day SIM, or 350µg/g/day MET treatment alone, with significantly less toxicity and mortality than DTX, establishing combination SIM and MET as a promising chemotherapeutic alternative for metastatic CRPC. PMID:25122066

  7. [EAU guidelines on prostate cancer. Part II: treatment of advanced, relapsing, and castration-resistant prostate cancer].

    PubMed

    Mottet, N; Bellmunt, J; Bolla, M; Joniau, S; Mason, M; Matveev, V; Schmid, H P; van der Kwast, T; Wiegel, T; Zattoni, F; Heidenreich, A

    2011-01-01

    Our aim is to present a summary of the 2010 version of the European Association of Urology (EAU) guidelines on the treatment of advanced, relapsing, and castration-resistant prostate cancer (CRPC). The working panel performed a literature review of the new data emerging from 2007 to 2010. The guidelines were updated, and the levels of evidence (LEs) and/or grades of recommendation (GR) were added to the text based on a systematic review of the literature, which included a search of online databases and bibliographic reviews. Luteinising hormone-releasing hormone (LHRH) agonists are the standard of care in metastatic prostate cancer (PCa). Although LHRH antagonists decrease testosterone without any testosterone surge, their clinical benefit remains to be determined. Complete androgen blockade has a small survival benefit of about 5%. Intermittent androgen deprivation (IAD) results in equivalent oncologic efficacy when compared with continuous androgen-deprivation therapy (ADT) in well-selected populations. In locally advanced and metastatic PCa, early ADT does not result in a significant survival advantage when compared with delayed ADT. Relapse after local therapy is defined by prostate-specific antigen (PSA) values > 0.2 ng/ml following radical prostatectomy (RP) and > 2 ng/ml above the nadir after radiation therapy (RT). Therapy for PSA relapse after RP includes salvage RT at PSA levels < 0.5 ng/ml and salvage RP or cryosurgical ablation of the prostate in radiation failures. Endorectal magnetic resonance imaging and 11C-choline positron emission tomography/computed tomography (CT) are of limited importance if the PSA is < 2.5 ng/ml; bone scans and CT can be omitted unless PSA is >20 ng/ml. Follow-up after ADT should include screening for the metabolic syndrome and an analysis of PSA and testosterone levels. Treatment of castration-resistant prostate cancer (CRPC) includes second-line hormonal therapy, novel agents, and chemotherapy with docetaxel at 75 mg/m(2

  8. EAU guidelines on prostate cancer. Part II: Treatment of advanced, relapsing, and castration-resistant prostate cancer.

    PubMed

    Mottet, Nicolas; Bellmunt, Joaquim; Bolla, Michel; Joniau, Steven; Mason, Malcolm; Matveev, Vsevolod; Schmid, Hans-Peter; Van der Kwast, Theo; Wiegel, Thomas; Zattoni, Filiberto; Heidenreich, Axel

    2011-04-01

    Our aim is to present a summary of the 2010 version of the European Association of Urology (EAU) guidelines on the treatment of advanced, relapsing, and castration-resistant prostate cancer (CRPC). The working panel performed a literature review of the new data emerging from 2007 to 2010. The guidelines were updated, and the levels of evidence (LEs) and/or grades of recommendation (GR) were added to the text based on a systematic review of the literature, which included a search of online databases and bibliographic reviews. Luteinising hormone-releasing hormone (LHRH) agonists are the standard of care in metastatic prostate cancer (PCa). Although LHRH antagonists decrease testosterone without any testosterone surge, their clinical benefit remains to be determined. Complete androgen blockade has a small survival benefit of about 5%. Intermittent androgen deprivation (IAD) results in equivalent oncologic efficacy when compared with continuous androgen-deprivation therapy (ADT) in well-selected populations. In locally advanced and metastatic PCa, early ADT does not result in a significant survival advantage when compared with delayed ADT. Relapse after local therapy is defined by prostate-specific antigen (PSA) values >0.2 ng/ml following radical prostatectomy (RP) and >2 ng/ml above the nadir after radiation therapy (RT). Therapy for PSA relapse after RP includes salvage RT at PSA levels <0.5 ng/ml and salvage RP or cryosurgical ablation of the prostate in radiation failures. Endorectal magnetic resonance imaging and (11)C-choline positron emission tomography/computed tomography (CT) are of limited importance if the PSA is <2.5 ng/ml; bone scans and CT can be omitted unless PSA is >20 ng/ml. Follow-up after ADT should include screening for the metabolic syndrome and an analysis of PSA and testosterone levels. Treatment of castration-resistant prostate cancer (CRPC) includes second-line hormonal therapy, novel agents, and chemotherapy with docetaxel at 75 mg/m(2

  9. New therapeutic options in metastatic castration-resistant prostate cancer: Can cost-effectiveness analysis help in treatment decisions?

    PubMed

    Wilson, Leslie; Tang, Jun; Zhong, Lixian; Balani, Gregory; Gipson, Gregory; Xiang, Pin; Yu, Dawn; Srinivas, Sandy

    2014-12-01

    To evaluate the cost-effectiveness of abiraterone, cabazitaxel, and enzalutamide compared to placebo for treatment of metastatic castration-resistant prostate cancer. A decision-tree model compared three treatment options for metastatic castration-resistant prostate cancer patients over 18 months from a societal perspective in 2012 USD. Chance nodes included baseline pain as a severity indicator, significant adverse effects (neutropenia, cardiac events, or seizures), and survival. Probabilities, survival rates, and health utilities were from clinical trials (COU-AA, TROPIC, and AFFIRM) and other published studies. Survival of enzalutamide was adjusted to match placebo groups across trials. Probabilistic sensitivity analyses, acceptability curves and net benefit calculations were performed. Abiraterone was the most cost-effective of the treatments ($123.4 K/quality-adjusted life year) compared to placebo, enzalutamide was $437.6 K/quality-adjusted life year compared to abiraterone, and cabazitaxel was $351.9 K/quality-adjusted life year compared to enzalutamide. Enzalutamide and cabazitaxel were not cost-effective compared to placebo at $154.3 K/quality-adjusted life year and $163.2 K/quality-adjusted life year, respectively. Acceptability curves showed abiraterone was cost-effective 29.3% of the time with a willingness to pay threshold of $100 K. The model was sensitive to changes in cost of the drugs, life expectancy, and survival rate. Sensitivity analysis shows that enzalutamide can become the most cost-effective option if the price of the medication decreased by 26% and other drug costs remained the same. Based on the cost-effective analysis, and survival adjustments necessary to match placebo groups, we would recommend abiraterone for treatment of metastatic castration-resistant prostate cancer despite not quite falling under the usually accepted willingness to pay threshold. Further analysis should examine comparative survival across the three drugs. © The

  10. Randomized, Double-Blind, Phase III Trial of Ipilimumab Versus Placebo in Asymptomatic or Minimally Symptomatic Patients With Metastatic Chemotherapy-Naive Castration-Resistant Prostate Cancer.

    PubMed

    Beer, Tomasz M; Kwon, Eugene D; Drake, Charles G; Fizazi, Karim; Logothetis, Christopher; Gravis, Gwenaelle; Ganju, Vinod; Polikoff, Jonathan; Saad, Fred; Humanski, Piotr; Piulats, Josep M; Gonzalez Mella, Pablo; Ng, Siobhan S; Jaeger, Dirk; Parnis, Francis X; Franke, Fabio A; Puente, Javier; Carvajal, Roman; Sengeløv, Lisa; McHenry, M Brent; Varma, Arvind; van den Eertwegh, Alfonsus J; Gerritsen, Winald

    2017-01-01

    Purpose Ipilimumab increases antitumor T-cell responses by binding to cytotoxic T-lymphocyte antigen 4. We evaluated treatment with ipilimumab in asymptomatic or minimally symptomatic patients with chemotherapy-naive metastatic castration-resistant prostate cancer without visceral metastases. Patients and Methods In this multicenter, double-blind, phase III trial, patients were randomly assigned (2:1) to ipilimumab 10 mg/kg or placebo every 3 weeks for up to four doses. Ipilimumab 10 mg/kg or placebo maintenance therapy was administered to nonprogressing patients every 3 months. The primary end point was overall survival (OS). Results Four hundred patients were randomly assigned to ipilimumab and 202 to placebo; 399 were treated with ipilimumab and 199 with placebo. Median OS was 28.7 months (95% CI, 24.5 to 32.5 months) in the ipilimumab arm versus 29.7 months (95% CI, 26.1 to 34.2 months) in the placebo arm (hazard ratio, 1.11; 95.87% CI, 0.88 to 1.39; P = .3667). Median progression-free survival was 5.6 months in the ipilimumab arm versus 3.8 with placebo arm (hazard ratio, 0.67; 95.87% CI, 0.55 to 0.81). Exploratory analyses showed a higher prostate-specific antigen response rate with ipilimumab (23%) than with placebo (8%). Diarrhea (15%) was the only grade 3 to 4 treatment-related adverse event (AE) reported in ≥ 10% of ipilimumab-treated patients. Nine (2%) deaths occurred in the ipilimumab arm due to treatment-related AEs; no deaths occurred in the placebo arm. Immune-related grade 3 to 4 AEs occurred in 31% and 2% of patients, respectively. Conclusion Ipilimumab did not improve OS in patients with metastatic castration-resistant prostate cancer. The observed increases in progression-free survival and prostate-specific antigen response rates suggest antitumor activity in a patient subset.

  11. Phase III, Randomized, Double-Blind, Multicenter Trial Comparing Orteronel (TAK-700) Plus Prednisone With Placebo Plus Prednisone in Patients With Metastatic Castration-Resistant Prostate Cancer That Has Progressed During or After Docetaxel-Based Therapy: ELM-PC 5

    PubMed Central

    Fizazi, Karim; Jones, Robert; Oudard, Stephane; Efstathiou, Eleni; Saad, Fred; de Wit, Ronald; De Bono, Johann; Cruz, Felipe Melo; Fountzilas, George; Ulys, Albertas; Carcano, Flavio; Agarwal, Neeraj; Agus, David; Bellmunt, Joaquim; Petrylak, Daniel P.; Lee, Shih-Yuan; Webb, Iain J.; Tejura, Bindu; Borgstein, Niels; Dreicer, Robert

    2015-01-01

    Purpose Orteronel (TAK-700) is an investigational, nonsteroidal, reversible, selective 17,20-lyase inhibitor. This study examined orteronel in patients with metastatic castration-resistant prostate cancer that progressed after docetaxel therapy. Patients and Methods In our study, 1,099 men were randomly assigned in a 2:1 schedule to receive orteronel 400 mg plus prednisone 5 mg twice daily or placebo plus prednisone 5 mg twice daily, stratified by region (Europe, North America [NA], and non-Europe/NA) and Brief Pain Inventory–Short Form worst pain score. Primary end point was overall survival (OS). Key secondary end points (radiographic progression-free survival [rPFS], ≥ 50% decrease of prostate-specific antigen [PSA50], and pain response at 12 weeks) were to undergo statistical testing only if the primary end point analysis was significant. Results The study was unblinded after crossing a prespecified OS futility boundary. The median OS was 17.0 months versus 15.2 months with orteronel-prednisone versus placebo-prednisone (hazard ratio [HR], 0.886; 95% CI, 0.739 to 1.062; P = .190). Improved rPFS was observed with orteronel-prednisone (median, 8.3 v 5.7 months; HR, 0.760; 95% CI, 0.653 to 0.885; P < .001). Orteronel-prednisone showed advantages over placebo-prednisone in PSA50 rate (25% v 10%, P < .001) and time to PSA progression (median, 5.5 v 2.9 months, P < .001) but not pain response rate (12% v 9%; P = .128). Adverse events (all grades) were generally more frequent with orteronel-prednisone, including nausea (42% v 26%), vomiting (36% v 17%), fatigue (29% v 23%), and increased amylase (14% v 2%). Conclusion Our study did not meet the primary end point of OS. Longer rPFS and a higher PSA50 rate with orteronel-prednisone indicate antitumor activity. PMID:25624429

  12. [Alpha emitter radium-223 dichloride: new therapy in castration-resistant prostate cancer with symptomatic bone metastases].

    PubMed

    Heinzer, H; König, F; Klutmann, S

    2014-04-01

    Radium-223 dichloride (Ra-223) is an alpha emitter with low toxicity for the treatment of patients with castrations-resistant prostate cancer (CRPC) and symptomatic bone metastases showing a 30% reduction in the risk of death, as compared to placebo. Because of the favorable physical and chemical characteristics, Ra-223 can be handled easily in daily practice based on interdisciplinary co-operation between urology and nuclear medicine. Ra-223 has been approved under the product name Xofigo® by the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA).

  13. [Bone-specific therapy with radium-223 dichloride : Castration-resistant prostate cancer with symptomatic bone metastases].

    PubMed

    Tauber, R; Gschwend, J; Scheidhauer, K; Eiber, M; Krönke, M

    2017-01-01

    Radium-223 dichloride (Xofigo®, Alpharadin) is approved for the treatment of metastatic castration-resistant prostate cancer with symptomatic bone metastases and no known visceral metastases. As a calcium mimetic, it is integrated into osteoplastic bone lesions and emits alpha particles with high energy which leads to local destruction of tumor cells. In the 2013 published ALSYMPCA trial, a significant advantage for overall survival and quality of life in comparison to placebo was found. Recent data suggest an increased potential in combination with next generation hormonal treatment.

  14. Sipuleucel-T for the Treatment of Patients With Metastatic Castrate-resistant Prostate Cancer: Considerations for Clinical Practice.

    PubMed

    Pieczonka, Christopher M; Telonis, Dimitrios; Mouraviev, Vladimir; Albala, David

    2015-01-01

    Sipuleucel-T treatment is associated with a significant and consistent survival benefit in patients with metastatic castrate-resistant prostate cancer. Most adverse events are infusion related, manageable, and of short duration. Early screening and diagnosis of metastatic disease is important, as the greatest survival benefit may occur in patients with a lower disease burden. The short duration of sipuleucel-T treatment facilitates the use of subsequent therapies. Sipuleucel-T is now being used in the clinic for patients with a lower disease burden. We present our own experience with the use of sipuleucel-T in the setting of a large urology practice.

  15. A Phase 2 Study of GW786034 (Pazopanib) with or without Bicalutamide in Patients with Castration Resistant Prostate Cancer

    PubMed Central

    Sridhar, Srikala S.; Joshua, Anthony M.; Gregg, Richard; Booth, Christopher M.; Murray, Nevin; Golubovic, Jovana; Wang, Lisa; Harris, Pamela; Chi, Kim N.

    2014-01-01

    Introduction Pazopanib is an oral vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitor. In this randomized open label phase II study, pazopanib alone or in combination with bicalutamide was evaluated in chemotherapy-naive castration resistant prostate cancer (CRPC) patients. Methods Patients received either pazopanib 800 mg daily (Arm A) or pazopanib 800 mg plus bicalutamide 50 mg daily (Arm B). A two-stage study design was used and the primary endpoint was PSA response rate (defined as a confirmed ≥50% decline from baseline). Results Twenty-three patients (Arm A 10, Arm B 13) were accrued. The main grade 3+ toxicities were hypertension, fatigue, decreased lymphocytes and increased ALT. Due to significant toxicity, the protocol was amended after the first 11 patients and the pazopanib starting dose was reduced to 600 mg daily. In arm A, of 9 evaluable patients there was 1(11%) patient with a PSA response, 3 (33%) with stable PSA, and 5 (56%) with PSA progression; in arm B of 12 evaluable patients: there were 2 (17%) patients with PSA responses, 6 (50%) with stable PSA and 4 (33%) with PSA progression. Median PFS (95%CI) was similar in both arms at 7.3 months (2.5 mo-not reached). Long term SD was seen in 4 patients who remained on treatment for 18 (Arm A), 26 (Arm A), 35 (Arm B) and 52 (Arm B) months. Conclusions In this unselected patient population, pazopanib either alone or in combination with bicalutamide failed to show sufficient activity to warrant further evaluation. However, four patients did had long-term benefit suggesting that targeting VEGFR pathway may still be relevant in selected patients, emphasizing the need for improved predictive markers for patients with CRPC. PMID:24993934

  16. Low β₂-adrenergic receptor level may promote development of castration resistant prostate cancer and altered steroid metabolism.

    PubMed

    Braadland, Peder Rustøen; Grytli, Helene Hartvedt; Ramberg, Håkon; Katz, Betina; Kellman, Ralf; Gauthier-Landry, Louis; Fazli, Ladan; Krobert, Kurt Allen; Wang, Wanzhong; Levy, Finn Olav; Bjartell, Anders; Berge, Viktor; Rennie, Paul S; Mellgren, Gunnar; Mælandsmo, Gunhild Mari; Svindland, Aud; Barbier, Olivier; Taskén, Kristin Austlid

    2016-01-12

    The underlying mechanisms responsible for the development of castration-resistant prostate cancer (CRPC) in patients who have undergone androgen deprivation therapy are not fully understood. This is the first study to address whether β2-adrenergic receptor (ADRB2)- mediated signaling may affect CRPC progression in vivo. By immunohistochemical analyses, we observed that low levels of ADRB2 is associated with a more rapid development of CRPC in a Norwegian patient cohort. To elucidate mechanisms by which ADRB2 may affect CRPC development, we stably transfected LNCaP cells with shRNAs to mimic low and high expression of ADRB2. Two UDP-glucuronosyltransferases, UGT2B15 and UGT2B17, involved in phase II metabolism of androgens, were strongly downregulated in two LNCaP shADRB2 cell lines. The low-ADRB2 LNCaP cell lines displayed lowered glucuronidation activities towards androgens than high-ADRB2 cells. Furthermore, increased levels of testosterone and enhanced androgen responsiveness were observed in LNCaP cells expressing low level of ADRB2. Interestingly, these cells grew faster than high-ADRB2 LNCaP cells, and sustained their low glucuronidation activity in castrated NOD/SCID mice. ADRB2 immunohistochemical staining intensity correlated with UGT2B15 staining intensity in independent TMA studies and with UGT2B17 in one TMA study. Similar to ADRB2, we show that low levels of UGT2B15 are associated with a more rapid CRPC progression. We propose a novel mechanism by which ADRB2 may affect the development of CRPC through downregulation of UGT2B15 and UGT2B17.

  17. Low β2-adrenergic receptor level may promote development of castration resistant prostate cancer and altered steroid metabolism

    PubMed Central

    Katz, Betina; Kellman, Ralf; Gauthier-Landry, Louis; Fazli, Ladan; Krobert, Kurt Allen; Wang, Wanzhong; Levy, Finn Olav; Bjartell, Anders; Berge, Viktor; Rennie, Paul S.; Mellgren, Gunnar; Mælandsmo, Gunhild Mari; Svindland, Aud; Barbier, Olivier; Taskén, Kristin Austlid

    2016-01-01

    The underlying mechanisms responsible for the development of castration-resistant prostate cancer (CRPC) in patients who have undergone androgen deprivation therapy are not fully understood. This is the first study to address whether β2-adrenergic receptor (ADRB2)- mediated signaling may affect CRPC progression in vivo. By immunohistochemical analyses, we observed that low levels of ADRB2 is associated with a more rapid development of CRPC in a Norwegian patient cohort. To elucidate mechanisms by which ADRB2 may affect CRPC development, we stably transfected LNCaP cells with shRNAs to mimic low and high expression of ADRB2. Two UDP-glucuronosyltransferases, UGT2B15 and UGT2B17, involved in phase II metabolism of androgens, were strongly downregulated in two LNCaP shADRB2 cell lines. The low-ADRB2 LNCaP cell lines displayed lowered glucuronidation activities towards androgens than high-ADRB2 cells. Furthermore, increased levels of testosterone and enhanced androgen responsiveness were observed in LNCaP cells expressing low level of ADRB2. Interestingly, these cells grew faster than high-ADRB2 LNCaP cells, and sustained their low glucuronidation activity in castrated NOD/SCID mice. ADRB2 immunohistochemical staining intensity correlated with UGT2B15 staining intensity in independent TMA studies and with UGT2B17 in one TMA study. Similar to ADRB2, we show that low levels of UGT2B15 are associated with a more rapid CRPC progression. We propose a novel mechanism by which ADRB2 may affect the development of CRPC through downregulation of UGT2B15 and UGT2B17. PMID:26646591

  18. A retrospective feasibility study of biweekly, reduced-dose docetaxel in Asian patients with castrate-resistant, metastatic prostate cancer.

    PubMed

    Kim, Hae Su; Lee, Ji Yun; Lee, Su Jin; Lim, Ho Yeong; Sung, Hyun Hwan; Jeon, Hwang Gyun; Jeong, Byong Chang; Seo, Seong Il; Jeon, Seong Soo; Lee, Hyun Moo; Choi, Han-Yong; Park, Se Hoon

    2017-08-22

    The aim of this retrospective study was to evaluate the clinical outcomes of reduced dose, biweekly docetaxel chemotherapy for Korean patients with castrate-resistant prostate cancer (CRPC). We retrospectively reviewed the medical records of 48 patients with metastatic CRPC who were treated with a biweekly regimen (intravenous docetaxel 40 mg/m(2) on day 1 plus prednisolone 5 mg twice daily) between 2012 and 2015 at Samsung Medical Center (Seoul, Korea). Prior to the adoption of a biweekly regimen in Oct 2013, our institutional standard chemotherapy was docetaxel 75 mg/m(2) every 3 weeks for patients with CRPC (n = 24). After Oct 2013, all chemotherapy-naïve patients with CRPC received a 40 mg/m(2) biweekly regimen (n = 24). The primary end point was a PSA response, defined as a greater than 50% decline in PSA level from baseline. The baseline characteristics of the patients in the two treatment groups were similar. The most common cause of treatment discontinuation was disease progression, which was exhibited by 17 patients (71%) in the 3-weekly group and 20 (75%) in the biweekly group. PSA responses were observed in 12 (50%) and 11 (46%) patients in the 3-weekly and biweekly groups, respectively (p = 0.683). Time to treatment failure (TTTF, 4.5 vs 3.9 months) and time-to-progression (TTP, 5.0 vs 4.2 months) were not significantly different between the 3-weekly and biweekly groups. Within the limitations of a retrospective study, the biweekly reduced dose docetaxel regimen was active and well-tolerated in Korean patients with metastatic CRPC.

  19. Sipuleucel-T immunotherapy for castration-resistant prostate cancer. A systematic review and meta-analysis.

    PubMed

    Kawalec, Paweł; Paszulewicz, Anna; Holko, Przemysław; Pilc, Andrzej

    2012-11-09

    Sipuleucel-T is a novel active cellular immunotherapy for the treatment of asymptomatic or minimally symptomatic metastatic castrate-resistant prostate cancer (mCRPC). It is assumed to be associated with less adverse events than conventional docetaxel-based chemotherapy. A systematic review of literature published between January, 1 1966 and February, 6 2012 was performed to assess the efficacy and safety of sipuleucel-T in patients with mCRPC. Databases were searched: Medline, EMBASE, Cochrane, CancerLit as well as ASCO and ESCO websites. Three randomized clinical trials with a total of 737 participants fulfilled established criteria. The overall survival of patients who received sipuleucel-T in comparison to the control group was significantly longer with a hazard ratio (HR) of 0.73 (95% CI: 0.61-0.88; p = 0.001). Time to disease progression was not prolonged using sipuleucel-T compared to placebo, HR = 0.89 (95% CI: 0.75-1.05; p = 0.18). Relative benefit (RB) of serum PSA level reduction of at least 50% for sipuleucel-T compared to placebo did not meet statistical significance, RB = 1.97 (95% CI: 0.48-8.14; p = 0.38). The safety population consisted of 729 patients with mCRPC. Compared to the control group, the pooled relative risks (RR) of all adverse events - RR = 1.03 (95% CI: 1.00-1.05; p = 0.06), grade 3 to 5 adverse events - RR = 0.98 (95% CI: 0.79-1.22; p = 0.86) and cerebrovascular events - RR = 1.93 (95% CI: 0.73-5.09; p = 0.18) were not significantly higher for men treated with sipuleucel-T. The use of sipuleucel-T prolonged the overall survival among men with mCRPC. No effect on time to disease progression was observed and the safety profile was acceptable.

  20. Androgen receptor expression in circulating tumour cells from castration-resistant prostate cancer patients treated with novel endocrine agents

    PubMed Central

    Crespo, M; van Dalum, G; Ferraldeschi, R; Zafeiriou, Z; Sideris, S; Lorente, D; Bianchini, D; Rodrigues, D N; Riisnaes, R; Miranda, S; Figueiredo, I; Flohr, P; Nowakowska, K; de Bono, J S; Terstappen, L W M M; Attard, G

    2015-01-01

    Background: Abiraterone and enzalutamide are novel endocrine treatments that abrogate androgen receptor (AR) signalling in castration-resistant prostate cancer (CRPC). Here, we developed a circulating tumour cells (CTCs)-based assay to evaluate AR expression in real-time in CRPC and investigated nuclear AR expression in CTCs in patients treated with enzalutamide and abiraterone. Methods: CTCs were captured and characterised using the CellSearch system. An automated algorithm to identify CTCs and quantify AR expression was employed. The primary aim was to evaluate the association between CTC AR expression and prior treatment with abiraterone or enzalutamide. Results: AR expression in CTCs was evaluated in 94 samples from 48 metastatic CRPC patients. We observed large intra-patient heterogeneity of AR expression in CTCs. Prior exposure to abiraterone or enzalutamide was not associated with a change in CTCs AR expression (median intensity and distribution of AR-positive classes). In support of this, we also confirmed maintained nuclear AR expression in tissue samples collected after progression on abiraterone. AR staining also identified additional AR-positive CD45-negative circulating cells that were CK-negative/weak and therefore missed using standard protocols. The number of these events correlated with traditional CTCs and was associated with worse outcome on univariate analysis. Conclusions: We developed a non-invasive method to monitor AR nuclear expression in CTCs. Our studies confirm nuclear AR expression in CRPC patients progressing on novel endocrine treatments. Owing to the significant heterogeneity of AR expression in CTCs, studies in larger cohorts of patients are required to identify associations with outcome. PMID:25719830

  1. Peri-prostatic Fat Volume Measurement as a Predictive Tool for Castration Resistance in Advanced Prostate Cancer.

    PubMed

    Salji, Mark; Hendry, Jane; Patel, Amit; Ahmad, Imran; Nixon, Colin; Leung, Hing Y

    2017-03-01

    Obesity and aggressive prostate cancer (PC) may be linked, but how local peri-prostatic fat relates to tumour response following androgen deprivation therapy (ADT) is unknown. To test if peri-prostatic fat volume (PPFV) predicts tumour response to ADT. We performed a retrospective study on consecutive patients receiving primary ADT. From staging pelvic magnetic resonance imaging scans, the PPFV was quantified with OsirixX 6.5 imaging software. Statistical (univariate and multivariate) analysis were performed using R Version 3.2.1. Of 224 consecutive patients, 61 with advanced (≥T3 or N1 or M1) disease had (3-mm high resolution axial sections) pelvic magnetic resonance imaging scan before ADT. Median age=75 yr; median PPFV=24.8cm(3) (range, 7.4-139.4cm(3)). PPFV was significantly higher in patients who developed castration resistant prostate cancer (CRPC; n=31), with a median of 37.9cm(3) compared with 16.1cm(3) (p <0.0001, Wilcoxon rank sum test) in patients who showed sustained response to ADT (n=30). Multivariate analysis using Cox proportional hazards models were performed controlling for known predictors of CRPC. PPFV was shown to be independent of all included factors, and the most significant predictor of time to CRPC. Using our multivariate model consisting of all known factors prior to ADT, PPFV significantly improved the area under the curve of the multivariate models receiver operating characteristic analysis. The main study limitation is a relatively small cohort to account for multiple variables, necessitating a future large-scale prospective analysis of PPFV in advanced PC. PPFV quantification in patients with advanced PC predicts tumour response to ADT. The amount of fat around the prostate predicts prostate cancer response to hormone treatment. Copyright © 2017 European Association of Urology. Published by Elsevier B.V. All rights reserved.

  2. Trial Design and Objectives for Castration-Resistant Prostate Cancer: Updated Recommendations From the Prostate Cancer Clinical Trials Working Group 3

    PubMed Central

    Morris, Michael J.; Stadler, Walter M.; Higano, Celestia; Basch, Ethan; Fizazi, Karim; Antonarakis, Emmanuel S.; Beer, Tomasz M.; Carducci, Michael A.; Chi, Kim N.; Corn, Paul G.; de Bono, Johann S.; Dreicer, Robert; George, Daniel J.; Heath, Elisabeth I.; Hussain, Maha; Kelly, Wm. Kevin; Liu, Glenn; Logothetis, Christopher; Nanus, David; Stein, Mark N.; Rathkopf, Dana E.; Slovin, Susan F.; Ryan, Charles J.; Sartor, Oliver; Small, Eric J.; Smith, Matthew Raymond; Sternberg, Cora N.; Taplin, Mary-Ellen; Wilding, George; Nelson, Peter S.; Schwartz, Lawrence H.; Halabi, Susan; Kantoff, Philip W.; Armstrong, Andrew J.

    2016-01-01

    Purpose Evolving treatments, disease phenotypes, and biology, together with a changing drug development environment, have created the need to revise castration-resistant prostate cancer (CRPC) clinical trial recommendations to succeed those from prior Prostate Cancer Clinical Trials Working Groups. Methods An international expert committee of prostate cancer clinical investigators (the Prostate Cancer Clinical Trials Working Group 3 [PCWG3]) was reconvened and expanded and met in 2012-2015 to formulate updated criteria on the basis of emerging trial data and validation studies of the Prostate Cancer Clinical Trials Working Group 2 recommendations. Results PCWG3 recommends that baseline patient assessment include tumor histology, detailed records of prior systemic treatments and responses, and a detailed reporting of disease subtypes based on an anatomic pattern of metastatic spread. New recommendations for trial outcome measures include the time to event end point of symptomatic skeletal events, as well as time to first metastasis and time to progression for trials in the nonmetastatic CRPC state. PCWG3 introduces the concept of no longer clinically benefiting to underscore the distinction between first evidence of progression and the clinical need to terminate or change treatment, and the importance of documenting progression in existing lesions as distinct from the development of new lesions. Serial biologic profiling using tumor samples from biopsies, blood-based diagnostics, and/or imaging is also recommended to gain insight into mechanisms of resistance and to identify predictive biomarkers of sensitivity for use in prospective trials. Conclusion PCWG3 moves drug development closer to unmet needs in clinical practice by focusing on disease manifestations most likely to affect prognosis adversely for therapeutics tested in both nonmetastatic and metastatic CRPC populations. Consultation with regulatory authorities is recommended if a trial is intended to seek

  3. Repurposing Itraconazole as a Treatment for Advanced Prostate Cancer: A Noncomparative Randomized Phase II Trial in Men With Metastatic Castration-Resistant Prostate Cancer

    PubMed Central

    Heath, Elisabeth I.; Smith, David C.; Rathkopf, Dana; Blackford, Amanda L.; Danila, Daniel C.; King, Serina; Frost, Anja; Ajiboye, A. Seun; Zhao, Ming; Mendonca, Janet; Kachhap, Sushant K.; Rudek, Michelle A.; Carducci, Michael A.

    2013-01-01

    Background. The antifungal drug itraconazole inhibits angiogenesis and Hedgehog signaling and delays tumor growth in murine prostate cancer xenograft models. We conducted a noncomparative, randomized, phase II study evaluating the antitumor efficacy of two doses of oral itraconazole in men with metastatic prostate cancer. Patients and Methods. We randomly assigned 46 men with chemotherapy-naïve metastatic castration-resistant prostate cancer (CRPC) to receive low-dose (200 mg/day) or high-dose (600 mg/day) itraconazole until disease progression or unacceptable toxicity. The primary endpoint was the prostate-specific antigen (PSA) progression-free survival (PPFS) rate at 24 weeks; a 45% success rate in either arm was prespecified as constituting clinical significance. Secondary endpoints included the progression-free survival (PFS) rate and PSA response rate (Prostate Cancer Working Group criteria). Exploratory outcomes included circulating tumor cell (CTC) enumeration, serum androgen measurements, as well as pharmacokinetic and pharmacodynamic analyses. Results. The high-dose arm enrolled to completion (n = 29), but the low-dose arm closed early (n = 17) because of a prespecified futility rule. The PPFS rates at 24 weeks were 11.8% in the low-dose arm and 48.0% in the high-dose arm. The median PFS times were 11.9 weeks and 35.9 weeks, respectively. PSA response rates were 0% and 14.3%, respectively. In addition, itraconazole had favorable effects on CTC counts, and it suppressed Hedgehog signaling in skin biopsy samples. Itraconazole did not reduce serum testosterone or dehydroepiandrostenedione sulfate levels. Common toxicities included fatigue, nausea, anorexia, rash, and a syndrome of hypokalemia, hypertension, and edema. Conclusion. High-dose itraconazole (600 mg/day) has modest antitumor activity in men with metastatic CRPC that is not mediated by testosterone suppression. PMID:23340005

  4. Trial Design and Objectives for Castration-Resistant Prostate Cancer: Updated Recommendations From the Prostate Cancer Clinical Trials Working Group 3.

    PubMed

    Scher, Howard I; Morris, Michael J; Stadler, Walter M; Higano, Celestia; Basch, Ethan; Fizazi, Karim; Antonarakis, Emmanuel S; Beer, Tomasz M; Carducci, Michael A; Chi, Kim N; Corn, Paul G; de Bono, Johann S; Dreicer, Robert; George, Daniel J; Heath, Elisabeth I; Hussain, Maha; Kelly, Wm Kevin; Liu, Glenn; Logothetis, Christopher; Nanus, David; Stein, Mark N; Rathkopf, Dana E; Slovin, Susan F; Ryan, Charles J; Sartor, Oliver; Small, Eric J; Smith, Matthew Raymond; Sternberg, Cora N; Taplin, Mary-Ellen; Wilding, George; Nelson, Peter S; Schwartz, Lawrence H; Halabi, Susan; Kantoff, Philip W; Armstrong, Andrew J

    2016-04-20

    Evolving treatments, disease phenotypes, and biology, together with a changing drug development environment, have created the need to revise castration-resistant prostate cancer (CRPC) clinical trial recommendations to succeed those from prior Prostate Cancer Clinical Trials Working Groups. An international expert committee of prostate cancer clinical investigators (the Prostate Cancer Clinical Trials Working Group 3 [PCWG3]) was reconvened and expanded and met in 2012-2015 to formulate updated criteria on the basis of emerging trial data and validation studies of the Prostate Cancer Clinical Trials Working Group 2 recommendations. PCWG3 recommends that baseline patient assessment include tumor histology, detailed records of prior systemic treatments and responses, and a detailed reporting of disease subtypes based on an anatomic pattern of metastatic spread. New recommendations for trial outcome measures include the time to event end point of symptomatic skeletal events, as well as time to first metastasis and time to progression for trials in the nonmetastatic CRPC state. PCWG3 introduces the concept of no longer clinically benefiting to underscore the distinction between first evidence of progression and the clinical need to terminate or change treatment, and the importance of documenting progression in existing lesions as distinct from the development of new lesions. Serial biologic profiling using tumor samples from biopsies, blood-based diagnostics, and/or imaging is also recommended to gain insight into mechanisms of resistance and to identify predictive biomarkers of sensitivity for use in prospective trials. PCWG3 moves drug development closer to unmet needs in clinical practice by focusing on disease manifestations most likely to affect prognosis adversely for therapeutics tested in both nonmetastatic and metastatic CRPC populations. Consultation with regulatory authorities is recommended if a trial is intended to seek support for drug approval. © 2016

  5. (177)Lu-PSMA-617 radioligand therapy and outcome in patients with metastasized castration-resistant prostate cancer.

    PubMed

    Bräuer, Axel; Grubert, Lena Sophie; Roll, Wolfgang; Schrader, Andres Jan; Schäfers, Michael; Bögemann, Martin; Rahbar, Kambiz

    2017-09-01

    Radioligand therapies targeting prostate-specific membrane antigen (PSMA) have been established for the treatment of metastasized castration-resistant prostate cancer (mCRPC) in the last decade and show promising response rates and a favourable toxicity profile. The aim of this study was to evaluate the overall survival (OS) and to identify parameters predicting outcome in mCRPC patients treated with (177)Lu-PSMA-617. Between December 2014 and January 2017, 59 consecutive patients (median age 72 years; interquartile range, (IQR, 66-76 years) with mCRPC, who had been treated with at least one next-generation antihormonal drug as well as chemotherapy, were included in this study. Biochemical response was evaluated using Prostate Cancer Working Group 3 (PCWG3) criteria. Survival was evaluated using Kaplan-Meier estimates and Cox regression proportional hazards model. Toxicity was assessed using Common Toxicity Criteria for Adverse Events (CTCAE). The study was approved by the local ethics committee. The 59 patients were treated with a total of 159 cycles (median 3 cycles, range 1-7) of (177)Lu-PSMA-617 (median dose 6.11 GBq, IQR 5.9-6.3 GBq). The median follow-up was 24 weeks (IQR 15-36 weeks). Follow-up data for at least 12 weeks (PCWG3) were available in 76% (45) of the patients. For outcome results data from all patients treated with at least one cycle were analysed. A decline in prostate-specific antigen (PSA) of ≥50% occurred in 53%, and a decline in PSA of any amount in 91% of patients. The estimated median OS was 32 weeks. An initial alkaline phosphatase (ALP) level <220 U/L and a PSA decline after the first cycle were associated with a longer OS (56 vs. 28 weeks, p < 0.01, and 56 vs. 29 weeks, p = 0.04, respectively). The median estimated PSA progression-free survival (PPFS) was 18 weeks. Only ALP level <220 U/L was significantly associated with a longer PPFS (41 vs. 18 weeks, p < 0.01). A PSA decline after the first cycle of (177)Lu

  6. Efficacy of enzalutamide following abiraterone acetate in chemotherapy-naive metastatic castration-resistant prostate cancer patients.

    PubMed

    Azad, Arun A; Eigl, Bernhard J; Murray, R Nevin; Kollmannsberger, Christian; Chi, Kim N

    2015-01-01

    The activity of enzalutamide after prior treatment with both abiraterone acetate (abiraterone) and docetaxel has been examined in several retrospective studies. However, limited data are available on the efficacy of enzalutamide following abiraterone in chemotherapy-naive patients with metastatic castration-resistant prostate cancer (mCRPC). To compare the activity of enzalutamide after abiraterone in docetaxel-experienced and docetaxel-naive mCRPC patients. The British Columbia Cancer Agency Cancer Registry was searched for mCRPC patients who received enzalutamide after prior abiraterone. Clinicopathologic characteristics, confirmed prostate-specific antigen (PSA) response rates (PSA decline ≥ 50% confirmed ≥ 3 wk later), and survival data were collected. Outcomes on enzalutamide were compared between docetaxel-experienced and docetaxel-naive patients using chi-square for PSA response and log-rank test for time to PSA progression and overall survival (OS). Univariate analysis was performed to identify variables associated with confirmed PSA response on enzalutamide, using either chi-square for categorical variables or logistic regression for continuous variables. A total of 115 patients received enzalutamide after abiraterone: 68 had received prior docetaxel and 47 were docetaxel naive. Median time on enzalutamide was 4.1 mo. Confirmed PSA response rates (22% vs 26%; p=0.8), median time to radiologic/clinical progression (4.6 mo vs 6.6 mo; p=0.6), and median OS (10.6 mo vs 8.6 mo; p=0.2) did not differ significantly between docetaxel-experienced and docetaxel-naive patients. No clinical variables (including prior response to abiraterone) were found to associate significantly with confirmed PSA response to enzalutamide. Antitumour activity of enzalutamide following abiraterone was limited in mCRPC patients irrespective of prior docetaxel use. Identifying clinical and molecular factors predictive of response to enzalutamide remains a high priority for future

  7. Nrdp1-mediated regulation of ErbB3 expression by the androgen receptor in androgen-dependent but not castrate-resistant prostate cancer cells

    PubMed Central

    Chen, Liqun; Siddiqui, Salma; Bose, Swagata; Mooso, Benjamin; Asuncion, Alfredo; Bedolla, Roble G.; Vinall, Ruth; Tepper, Clifford G.; Gandour-Edwards, Regina; Shi, XuBao; Lu, Xiao-Hua; Siddiqui, Javed; Chinnaiyan, Arul M.; Mehra, Rohit; deVere White, Ralph W.; Carraway, Kermit L.; Ghosh, Paramita M.

    2010-01-01

    Patients with advanced prostate cancer (PCa) are initially susceptible to androgen withdrawal (AW), but ultimately develop resistance to this therapy (castration-resistant PCa, CRPC). Here we show that AW can promote CRPC development by increasing the levels of the receptor tyrosine kinase (RTK) ErbB3 in androgen-dependent PCa, resulting in AW-resistant cell cycle progression and increased androgen receptor (AR) transcriptional activity. CRPC cell lines and human prostate cancer tissue overexpressed ErbB3, whereas downregulation of ErbB3 prevented CRPC cell growth. Investigation of the mechanism by which AW augments ErbB3, using normal prostate derived pRNS-1-1 cells, and androgen-dependent PCa lines LNCaP, PC346C and CWR22 mouse xenografts, revealed that the AR suppresses ErbB3 protein levels, while AW relieves this suppression, demonstrating for the first time negative regulation of ErbB3 by AR. We show that AR activation promotes ErbB3 degradation in androgen-dependent cells, and that this effect is mediated by AR-dependent transcriptional upregulation of Nrdp1, an E3 ubiquitin ligase that targets ErbB3 for degradation but whose role in PCa has not been previously examined. Therefore, AW decreases Nrdp1 expression, promoting ErbB3 protein accumulation, and leading to AR-independent proliferation. However, in CRPC sublines of LNCaP and CWR22 which strongly overexpress the AR, ErbB3 levels remain elevated due to constitutive suppression of Nrdp1, which prevents AR regulation of Nrdp1. Our observations point to a model of CRPC development where progression of PCa to castration-resistance is associated with the inability of AR to transcriptionally regulate Nrdp1, and predict that inhibition of ErbB3 during AW may impair CRPC development. PMID:20587519

  8. Exploring the optimal sequence of abiraterone and enzalutamide in patients with chemotherapy-naïve castration-resistant prostate cancer: The Kyoto-Baltimore collaboration.

    PubMed

    Terada, Naoki; Maughan, Benjamin L; Akamatsu, Shusuke; Kobayashi, Takashi; Yamasaki, Toshinari; Inoue, Takahiro; Kamba, Tomomi; Ogawa, Osamu; Antonarakis, Emmanuel S

    2017-06-01

    To evaluate and compare the efficacy of sequential treatment with abiraterone followed by enzalutamide or vice versa for castration-resistant prostate cancer. We retrospectively evaluated data on 198 consecutive chemotherapy-naïve patients who had received both abiraterone and enzalutamide for castration-resistant prostate cancer at Kyoto University Hospital (including satellite hospitals) and at Johns Hopkins Cancer Center. Prostate-specific antigen progression-free survival and overall survival in patients treated with sequential abiraterone-to-enzalutamide versus enzalutamide-to-abiraterone without intervening therapies were compared. Overall, 113 patients were treated with the abiraterone-to-enzalutamide sequence and 85 with the enzalutamide-to-abiraterone sequence. Median prostate-specific antigen progression-free survival was not significantly different between abiraterone and enzalutamide in the first-line setting (hazard ratio 0.88, 95% confidence interval 0.66-1.19, P = 0.412), but there was an advantage favoring enzalutamide compared with abiraterone in the second-line setting (hazard ratio 0.67, 95% confidence interval 0.49-0.91, P = 0.009). Furthermore, the combined prostate-specific antigen progression-free survival was significantly longer in the abiraterone-to-enzalutamide sequence than in the enzalutamide-to-abiraterone sequence (hazard ratio 0.56, 95% confidence interval 0.41-0.76, P < 0.001). The difference was significant even in multivariate analyses (hazard ratio 0.65, 95% confidence interval 0.42-0.99, P = 0.044). There was no statistical difference in overall survival between the two sequences in univariate (hazard ratio 0.88, 95% confidence interval 0.53-1.43, P = 0.599) and multivariate analyses (hazard ratio 0.81, 95% confidence interval 0.49-1.35, P = 0.427). The abiraterone-to-enzalutamide sequence might have more favorable efficacy in terms of combined prostate-specific antigen progression-free survival than the

  9. EAU guidelines on prostate cancer. Part II: Treatment of advanced, relapsing, and castration-resistant prostate cancer.

    PubMed

    Heidenreich, Axel; Bastian, Patrick J; Bellmunt, Joaquim; Bolla, Michel; Joniau, Steven; van der Kwast, Theodor; Mason, Malcolm; Matveev, Vsevolod; Wiegel, Thomas; Zattoni, Filiberto; Mottet, Nicolas

    2014-02-01

    To present a summary of the 2013 version of the European Association of Urology (EAU) guidelines on the treatment of advanced, relapsing, and castration-resistant prostate cancer (CRPC). The working panel performed a literature review of the new data (2011-2013). The guidelines were updated, and levels of evidence and/or grades of recommendation were added to the text based on a systematic review of the literature that included a search of online databases and bibliographic reviews. Luteinising hormone-releasing hormone (LHRH) agonists are the standard of care in metastatic prostate cancer (PCa). LHRH antagonists decrease testosterone without any testosterone surge, and they may be associated with an oncologic benefit compared with LHRH analogues. Complete androgen blockade has a small survival benefit of about 5%. Intermittent androgen deprivation results in noninferior oncologic efficacy when compared with continuous androgen-deprivation therapy (ADT) in well-selected populations. In locally advanced and metastatic PCa, early ADT does not result in a significant survival advantage when compared with delayed ADT. Relapse after local therapy is defined by prostate-specific antigen (PSA) values >0.2 ng/ml following radical prostatectomy (RP) and >2 ng/ml above the nadir and after radiation therapy (RT). Therapy for PSA relapse after RP includes salvage RT (SRT) at PSA levels <0.5 ng/ml and SRP or cryosurgical ablation of the prostate in radiation failures. Endorectal magnetic resonance imaging and 11C-choline positron emission tomography/computed tomography (PET/CT) are of limited importance if the PSA is <1.0 ng/ml; bone scans and CT can be omitted unless PSA is >20 ng/ml. Follow-up after ADT should include analysis of PSA and testosterone levels, and screening for cardiovascular disease and metabolic syndrome. Treatment of CRPC includes sipuleucel-T, abiraterone acetate plus prednisone (AA/P), or chemotherapy with docetaxel at 75mg/m(2) every 3 wk. Cabazitaxel, AA

  10. The Influence of Prednisone on the Efficacy of Docetaxel in Men with Metastatic Castration-Resistant Prostate Cancer

    PubMed Central

    Teply, Benjamin A.; Luber, Brandon; Denmeade, Samuel R.; Antonarakis, Emmanuel S.

    2015-01-01

    BACKGROUND Prednisone and other corticosteroids can provide palliation and tumor responses in patients with prostate cancer. The combination of docetaxel and prednisone was the first treatment shown to prolong survival in men with metastatic castration-resistant prostate cancer (mCRPC). Since the approval of docetaxel in 2004, additional treatments are available, including abiraterone, which is also administered with prednisone. Therefore, patients are increasingly likely to have prednisone therapy several times throughout their disease course, and the contribution of prednisone to the efficacy of docetaxel is unknown. METHODS We conducted a retrospective study of patients with mCPRC treated with docetaxel at our institution between 2004–2014. Patients were divided into 2 cohorts based upon whether prednisone was co-administered with docetaxel. Cohorts were further stratified based upon prior prednisone (with abiraterone) or hydrocortisone (with ketoconazole) use. The primary endpoint was clinical/radiographic progression-free survival (PFS). The secondary endpoints were >50% PSA response rate and PSA progression-free survival (PSA-PFS). A multivariable cox regression model was constructed to determine if prednisone use was independently predictive of PFS. RESULTS We identified 200 consecutive patients for inclusion in the study: 131 men received docetaxel with prednisone and 69 received docetaxel alone. The docetaxel-prednisone cohort had superior PFS compared to the docetaxel-alone cohort (median PFS: 7.8 vs 6.2 months, HR 0.68 [95% CI 0.48–0.97], p=0.03). Prednisone was associated with a reduced risk of progression on docetaxel in the propensity score-weighted multivariable Cox model (p=0.002). Among abiraterone- or ketoconazole-pretreated patients, no difference in PFS was observed between prednisone-containing and non-prednisone containing cohorts (median PFS: 7.1 vs 6.3 months, HR 0.96 [95% CI 0.59–1.57], p=0.87). CONCLUSIONS The incorporation of

  11. 2-Weekly versus 3-weekly docetaxel to treat castration-resistant advanced prostate cancer: a randomised, phase 3 trial.

    PubMed

    Kellokumpu-Lehtinen, Pirkko-Liisa; Harmenberg, Ulrika; Joensuu, Timo; McDermott, Ray; Hervonen, Petteri; Ginman, Claes; Luukkaa, Marjaana; Nyandoto, Paul; Hemminki, Akseli; Nilsson, Sten; McCaffrey, John; Asola, Raija; Turpeenniemi-Hujanen, Taina; Laestadius, Fredrik; Tasmuth, Tiina; Sandberg, Katinka; Keane, Maccon; Lehtinen, Ilari; Luukkaala, Tiina; Joensuu, Heikki

    2013-02-01

    Docetaxel administered every 3 weeks is a standard treatment for castration-resistant advanced prostate cancer. We hypothesised that 2-weekly administration of docetaxel would be better tolerated than 3-weekly docetaxel in patients with castration-resistant advanced prostate cancer, and did a prospective, multicentre, randomised, phase 3 study to compare efficacy and safety. Eligible patients had advanced prostate cancer (metastasis, a prostate-specific-antigen test result of more than 10·0 ng/mL, and WHO performance status score of 0-2), had received no chemotherapy (except with estramustine), had undergone surgical or chemical castration, and had been referred to a treatment centre in Finland, Ireland, or Sweden. Enrolment and treatment were done between March 1, 2004, and May 31, 2009. Randomisation was done centrally and stratified by centre and WHO performance status score of 0-1 vs 2. Patients were assigned 75 mg/m(2) docetaxel intravenously on day 1 of a 3-week cycle, or 50 mg/m(2) docetaxel intravenously on days 1 and 15 of a 4-week cycle. 10 mg oral prednisolone was administered daily to all patients. The primary endpoint was time to treatment failure (TTTF). We assessed data in the per-protocol population. This study is registered with ClinicalTrials.gov, number NCT00255606. 177 patients were randomly assigned to the 2-weekly docetaxel group and 184 to the 3-weekly group. 170 patients in the 2-weekly group and 176 in the 3-weekly group were included in the analysis. The 2-weekly administration was associated with significantly longer TTTF than was 3-weekly administration (5·6 months, 95% CI 5·0-6·2 vs 4·9 months, 4·5-5·4; hazard ratio 1·3, 95% CI 1·1-1·6, p=0·014). Grade 3-4 adverse events occurred more frequently in the 3-weekly than in the 2-weekly administration group, including neutropenia (93 [53%] vs 61 [36%]), leucopenia (51 [29%] vs 22 [13%]), and febrile neutropenia (25 [14%] vs six [4%]). Neutropenic infections were reported more

  12. Silencing CAPN2 Expression Inhibited Castration-Resistant Prostate Cancer Cells Proliferation and Invasion via AKT/mTOR Signal Pathway

    PubMed Central

    Li, Pu; Miao, Chenkui; Liang, Chao; Shao, Pengfei

    2017-01-01

    The mRNA expression of CAPN2 was upregulated in CRPC cells (DU145 and PC3) than that in non-CRPC cells. Silencing CAPN2 expression could inhibit DU145 and PC3 cells proliferation by cell cycle arrest at G1 phase. Knockdown of CPAN2 level suppressed the migration and invasion capacity of CRPC cells by reducing matrix metalloproteinase-2 (MMP-2) and MMP-9 activation, as well as repressing the phosphorylation protein expression of AKT and mTOR. In addition, we found that the expression of CAPN2 was elevated in Pca tissues than that in normal control tissues. Therefore, we showed the important roles of CAPN2 in the development and progression in CRPC cells, suggesting a new therapeutic intervention for treating castration-resistant prostate cancer patients. PMID:28280729

  13. A low carbohydrate, high protein diet suppresses intratumoral androgen synthesis and slows castration-resistant prostate tumor growth in mice.

    PubMed

    Fokidis, H Bobby; Yieng Chin, Mei; Ho, Victor W; Adomat, Hans H; Soma, Kiran K; Fazli, Ladan; Nip, Ka Mun; Cox, Michael; Krystal, Gerald; Zoubeidi, Amina; Tomlinson Guns, Emma S

    2015-06-01

    Dietary factors continue to preside as dominant influences in prostate cancer prevalence and progression-free survival following primary treatment. We investigated the influence of a low carbohydrate diet, compared to a typical Western diet, on prostate cancer (PCa) tumor growth in vivo. LNCaP xenograft tumor growth was studied in both intact and castrated mice, representing a more advanced castration resistant PCa (CRPC). No differences in LNCaP tumor progression (total tumor volume) with diet was observed for intact mice (P = 0.471) however, castrated mice on the Low Carb diet saw a statistically significant reduction in tumor growth rate compared with Western diet fed mice (P = 0.017). No correlation with serum PSA was observed. Steroid profiles, alongside serum cholesterol and cholesteryl ester levels, were significantly altered by both diet and castration. Specifically, DHT concentration with the Low Carb diet was 58% that of the CRPC-bearing mice on the Western diet. Enzymes in the steroidogenesis pathway were directly impacted and tumors isolated from intact mice on the Low Carb diet had higher AKR1C3 protein levels and lower HSD17B2 protein levels than intact mice on the Western diet (ARK1C3: P = 0.074; HSD17B2: P = 0.091, with α = 0.1). In contrast, CRPC tumors from mice on Low Carb diets had higher concentrations of both HSD17B2 (P = 0.016) and SRD5A1 (P = 0.058 with α = 0.1) enzymes. There was no correlation between tumor growth in castrated mice for Low Carb diet versus Western diet and (a) serum insulin (b) GH serum levels (c) insulin receptor (IR) or (d) IGF-1R in tumor tissue. Intact mice fed Western diet had higher serum insulin which was associated with significantly higher blood glucose and tumor tissue IR. We conclude that both diet and castration have a significant impact on the endocrinology of mice bearing LNCaP xenograft tumors. The observed effects of diet on cholesterol and steroid regulation impact tumor tissue DHT specifically and are

  14. Cost-effectiveness analysis of abiraterone and sipuleucel-T in asymptomatic metastatic castration-resistant prostate cancer.

    PubMed

    Gong, Cynthia L; Hay, Joel W

    2014-10-01

    Of patients diagnosed with prostate cancer, 0% to 20% experience disease progression to metastatic castration-resistant prostate cancer (mCRPC). Recently, 4 novel therapies have been introduced for the treatment of mCRPC; of these, abiraterone and sipuleucel-T have been studied in the asymptomatic, pre-docetaxel population. Both have shown clinical benefits compared with placebo. This study evaluated the cost-effectiveness of abiraterone acetate and sipuleucel-T compared with prednisone in asymptomatic, pre-docetaxel mCRPC from a US societal perspective. A Markov model was constructed to simulate stable disease, progressed disease, and death. Survival and event rates were derived from published clinical trial data. Costs were derived from the literature and government reimbursement schedules. Outcomes were measured as average cost-effectiveness ratios (ACERs), incremental cost-effectiveness ratios (ICERs), and net monetary benefits (NMBs). One-way and probabilistic sensitivity analyses were conducted to test the robustness of the model. The base-case ACER was $114K/quality-adjusted life-years (QALY) for abiraterone, $85K/QALY for sipuleucel-T, and $31K/QALY for prednisone. The base-case ICER was $389K/QALY for abiraterone and $547K/QALY for sipuleucel-T. Prednisone dominates both abiraterone and sipuleucel-T in terms of NMB at willingness-to-pay (WTP) thresholds of $400K or less. One-way sensitivity analyses revealed that the model was most sensitive to overall survival and utility inputs. Probabilistic sensitivity analyses showed abiraterone to be cost-effective 50% or more of the time at a WTP of greater than $400K, whereas sipuleucel-T was cost-effective 50% or more of the time at a WTP of greater than $270K. Neither abiraterone nor sipuleucel-T was found to be cost-effective compared with prednisone in the treatment of asymptomatic, pre-docetaxel mCRPC. Copyright © 2014 by the National Comprehensive Cancer Network.

  15. Comparing Sequencing of Abiraterone and Enzalutamide in Men With Metastatic Castration-Resistant Prostate Cancer: A Retrospective Study.

    PubMed

    Maughan, Benjamin L; Luber, Brandon; Nadal, Rosa; Antonarakis, Emmanuel S

    2017-01-01

    There are no validated clinical decision tools to aid optimal treatment selection in men with metastatic castration-resistant prostate cancer (mCRPC). Frequently, abiraterone and enzalutamide are used prior to chemotherapy in mCRPC, given the more favorable safety profiles. However, there is no published data on clinical outcomes regarding best sequencing of these two agents. A retrospective analysis of consecutive mCRPC patients treated with enzalutamide and abiraterone at Johns Hopkins was conducted. Patients were treated with sequential enzalutamide and abiraterone, in either order. The combined progression-free survival (PFS: PFS1 + PFS2) of abiraterone-to-enzalutamide was compared to the reverse sequence, where PFS1 and PFS2 represented clinical/radiographic progression-free survival on the first and second agents, respectively. Overall survival (OS) from the start of the first therapy to death and PSA response rates (defined as ≥50% PSA declines at any time) were also compared between groups. Outcomes were adjusted using propensity score-weighted multivariable Cox analyses. Eighty-one patients who satisfied our entry criteria were identified: 65 in the abiraterone-to-enzalutamide group and 16 in the enzalutamide-to-abiraterone group. There were no significant baseline differences between groups. Multivariable analysis suggested a difference between groups favoring the abiraterone-to-enzalutamide sequence with respect to combined PFS (HR 0.37, 95%CI 0.22-0.64, P < 0.001). There was no statistical difference in OS between the groups after multivariable adjustment (HR 0.57, 95%CI 0.29-1.11, P = 0.098), although OS was numerically superior in the abiraterone-to-enzalutamide group. We observed differences suggesting improved outcomes favoring the abiraterone-to-enzalutamide sequence in men with mCRPC, with statistical confirmation in terms of PFS but not OS. Prospective studies are required to verify these hypothesis-generating findings. Further

  16. Phase II study of Lutetium-177-labeled anti-prostate-specific membrane antigen monoclonal antibody J591 for metastatic castration-resistant prostate cancer.

    PubMed

    Tagawa, Scott T; Milowsky, Matthew I; Morris, Michael; Vallabhajosula, Shankar; Christos, Paul; Akhtar, Naveed H; Osborne, Joseph; Goldsmith, Stanley J; Larson, Steve; Taskar, Neeta Pandit; Scher, Howard I; Bander, Neil H; Nanus, David M

    2013-09-15

    To assess the efficacy of a single infusion of radiolabeled anti-prostate-specific membrane antigen (PSMA) monoclonal antibody J591 (lutetium-177; (177)Lu) by prostate-specific antigen (PSA) decline, measurable disease response, and survival. In this dual-center phase II study, two cohorts with progressive metastatic castration-resistant prostate cancer received one dose of (177)Lu-J591 (15 patients at 65 mCi/m(2), 17 at 70 mCi/m(2)) with radionuclide imaging. Expansion cohort (n = 15) received 70 mCi/m(2) to verify response rate and examine biomarkers. Forty-seven patients who progressed after hormonal therapies (55.3% also received prior chemotherapy) received (177)Lu-J591. A total of 10.6% experienced ≥50% decline in PSA, 36.2% experienced ≥30% decline, and 59.6% experienced any PSA decline following their single treatment. One of 12 with measurable disease experienced a partial radiographic response (8 with stable disease). Sites of prostate cancer metastases were targeted in 44 of 47 (93.6%) as determined by planar imaging. All experienced reversible hematologic toxicity, with grade 4 thrombocytopenia occurring in 46.8% (29.8% received platelet transfusions) without significant hemorrhage. A total of 25.5% experienced grade 4 neutropenia, with one episode of febrile neutropenia. The phase I maximum tolerated dose (70 mCi/m(2)) resulted in more 30% PSA declines (46.9% vs. 13.3%, P = 0.048) and longer survival (21.8 vs. 11.9 months, P = 0.03), but also more grade 4 hematologic toxicity and platelet transfusions. No serious nonhematologic toxicity occurred. Those with poor PSMA imaging were less likely to respond. A single dose of (177)Lu-J591 was well tolerated with reversible myelosuppression. Accurate tumor targeting and PSA responses were seen with evidence of dose response. Imaging biomarkers seem promising. ©2013 AACR.

  17. [177Lu-PSMA-617 therapy, dosimetry and follow-up in patients with metastatic castration-resistant prostate cancer].

    PubMed

    Fendler, Wolfgang P; Kratochwil, Clemens; Ahmadzadehfar, Hojjat; Rahbar, Kambiz; Baum, Richard P; Schmidt, Matthias; Pfestroff, Andreas; Lützen, Ulf; Prasad, Vikas; Heinzel, Alexander; Heuschkel, Martin; Ruf, Juri; Bartenstein, Peter; Krause, Bernd J

    2016-06-28

    Radioligand therapy (RLT) using 177Lu labelled inhibitors of the prostate-specific membrane antigen (177Lu-PSMA) is performed in patients with metastatic castration-resistant prostate cancer (mCRPC) after exhaustion of other options. German University Clinics offer RLT since 2013 on a compassionate use basis. The present consensus document includes recommendations for RLT with 177Lu-PSMA-617. These consensus statements were developed by an expert panel formed by the German Society of Nuclear Medicine (DGN) in December 2015. Statements include recommendations for indication, baseline tests, therapy protocol, concomitant therapy, dosimetry, and follow-up. Consensus recommendations aim to inform the attending medical staff, standardize 177Lu-PSMA-617 RLT, and improve quality of individual patient care.

  18. Nrdp1-mediated regulation of ErbB3 expression by the androgen receptor in androgen-dependent but not castrate-resistant prostate cancer cells.

    PubMed

    Chen, Liqun; Siddiqui, Salma; Bose, Swagata; Mooso, Benjamin; Asuncion, Alfredo; Bedolla, Roble G; Vinall, Ruth; Tepper, Clifford G; Gandour-Edwards, Regina; Shi, Xubao; Lu, Xiao-Hua; Siddiqui, Javed; Chinnaiyan, Arul M; Mehra, Rohit; Devere White, Ralph W; Carraway, Kermit L; Ghosh, Paramita M

    2010-07-15

    Patients with advanced prostate cancer (PCa) are initially susceptible to androgen withdrawal (AW), but ultimately develop resistance to this therapy (castration-resistant PCa, CRPC). Here, we show that AW can promote CRPC development by increasing the levels of the receptor tyrosine kinase ErbB3 in androgen-dependent PCa, resulting in AW-resistant cell cycle progression and increased androgen receptor (AR) transcriptional activity. CRPC cell lines and human PCa tissue overexpressed ErbB3, whereas downregulation of ErbB3 prevented CRPC cell growth. Investigation of the mechanism by which AW augments ErbB3, using normal prostate-derived pRNS-1-1 cells, and androgen-dependent PCa lines LNCaP, PC346C, and CWR22 mouse xenografts, revealed that the AR suppresses ErbB3 protein levels, whereas AW relieves this suppression, showing for the first time the negative regulation of ErbB3 by AR. We show that AR activation promotes ErbB3 degradation in androgen-dependent cells, and that this effect is mediated by AR-dependent transcriptional upregulation of neuregulin receptor degradation protein-1 (Nrdp1), an E3 ubiquitin ligase that targets ErbB3 for degradation but whose role in PCa has not been previously examined. Therefore, AW decreases Nrdp1 expression, promoting ErbB3 protein accumulation, and leading to AR-independent proliferation. However, in CRPC sublines of LNCaP and CWR22, which strongly overexpress the AR, ErbB3 levels remain elevated due to constitutive suppression of Nrdp1, which prevents AR regulation of Nrdp1. Our observations point to a model of CRPC development in which progression of PCa to castration resistance is associated with the inability of AR to transcriptionally regulate Nrdp1, and predict that inhibition of ErbB3 during AW may impair CRPC development.

  19. The N-terminal domain of the androgen receptor drives its nuclear localization in castration-resistant prostate cancer cells

    PubMed Central

    Dar, Javid A.; Masoodi, Khalid Z.; Eisermann, Kurtis; Isharwal, Sudhir; Ai, Junkui; Pascal, Laura E.; Nelson, Joel B.; Wang, Zhou

    2014-01-01

    Androgen-independent nuclear localization is required for androgen receptor (AR) transactivation in castration-resistant prostate cancer (CRPC) and should be a key step leading to castration resistance. However, mechanism(s) leading to androgen-independent AR nuclear localization are poorly understood. Since the N-terminal domain (NTD) of AR plays a role in transactivation under androgen-depleted conditions, we investigated the role of NTD in AR nuclear localization in CRPC. Deletion mutagenesis was used to identify amino acid sequences in the NTD essential for its androgen-independent nuclear localization in C4-2, a widely used CRPC cell line. Deletion mutants of AR tagged with green fluorescent protein (GFP) at the 5`-end were generated and their signal distribution was investigated in C4-2 cells by fluorescent microscopy. Our results showed that the region of a.a. 294–556 was required for androgen-independent AR nuclear localization whereas a.a. 1–293 mediates Hsp90 regulation of AR nuclear localization in CRPC cells. Although a.a. 294–556 does not contain a nuclear import signal, it was able to enhance DHT-induced import of the ligand binding domain (LBD). Also, transactivation of the NTD could be uncoupled from its modulation of AR nuclear localization in C4-2 cells. These observations suggest an important role of NTD in AR intracellular trafficking and androgen-independent AR nuclear localization in CRPC cells. PMID:24662325

  20. Imaging, procedural and clinical variables associated with tumor yield on bone biopsy in metastatic castration-resistant prostate cancer.

    PubMed

    McKay, R R; Zukotynski, K A; Werner, L; Voznesensky, O; Wu, J S; Smith, S E; Jiang, Z; Melnick, K; Yuan, X; Kantoff, P W; Montgomery, B; Balk, S P; Taplin, M-E

    2014-12-01

    Understanding the mechanisms driving disease progression is fundamental to identifying new therapeutic targets for the treatment of men with metastatic castration-resistant prostate cancer (mCRPC). Owing to the prevalence of bone metastases in mCRPC, obtaining sufficient tumor tissue for analysis has historically been a challenge. In this exploratory analysis, we evaluated imaging, procedural and clinical variables associated with tumor yield on image-guided bone biopsy in men with mCRPC. Clinical data were collected prospectively from men with mCRPC enrolled on a phase II trial with serial metastasis biopsies performed according to standard clinical protocol. Imaging was retrospectively reviewed. We evaluated the percent positive biopsy cores (PPC), calculated as the number of positive cores divided by the total number of cores collected per biopsy. Twenty-nine men had 39 bone biopsies. Seventy-seven percent of bone biopsies had at least one positive biopsy core. We determined that lesion size and distance from the skin to the lesion edge correlated with tumor yield on biopsy (median PPC 75% versus 42% for lesions >8.8 cm(3) versus ⩽ 8.8 cm(3), respectively, P=0.05; median PPC 33% versus 71% for distance ⩾ 6.1 versus <6.1 cm, respectively, P = 0.02). There was a trend towards increased tumor yield in patients with increased uptake on radionuclide bone scan, higher calcium levels and shorter duration of osteoclast-targeting therapy, although this was not statistically significant. Ten men had 14 soft tissue biopsies. All soft tissue biopsies had at least one positive biopsy core. This exploratory analysis suggests that there are imaging, procedural and clinical variables that have an impact on image-guided bone biopsy yield. In order to maximize harvest of prostate cancer tissue, we have incorporated a prospective analysis of the metrics described here as part of a multi-institutional project aiming to use the molecular characterization of mCRPC tumors to

  1. Phase-1 study of abiraterone acetate in chemotherapy-naïve Japanese patients with castration-resistant prostate cancer

    PubMed Central

    Matsubara, Nobuaki; Uemura, Hiroji; Fukui, Iwao; Niwakawa, Masashi; Yamaguchi, Akito; Iizuka, Koho; Akaza, Hideyuki

    2014-01-01

    Persistent androgen synthesis under castration status in adrenal gland, testes and tumor cells is thought to be one of the major causes of development and progression of castration-resistant prostate cancer (CRPC). Abiraterone acetate (AA), the prodrug of abiraterone, which is an inhibitor of androgen synthesis enzymes, was evaluated for pharmacokinetics, pharmacodynamics, preliminary efficacy and safety in Japanese patients with CRPC in a phase-1, open-label and dose-escalation study. Chemotherapy-naïve Japanese CRPC patients (N = 27) received one of four AA daily doses (250 mg [n = 9], 500 mg [n = 6], 1000 [1 h premeal] mg [n = 6] and 1000 [2 h postmeal] mg [n = 6]) continuously through 28-day treatment cycles. In the first cycle, AA monotherapy was given on days 1–7 for pharmacokinetics, and AA plus prednisone (5 mg twice daily) from days 8 to 28. Of 27 patients, 9 continued treatment with AA until the data cut-off date (18 July 2013). Over the evaluated dose range, plasma abiraterone concentrations increased with dose, with median tmax 2–3 h. At each dose level, mean serum corticosterone concentrations increased, while testosterone and dehydroepiandrosterone sulfate concentrations rapidly decreased following a single AA dose and were further reduced to near the quantification limit on day 8 regardless of the dose. At least 3 patients from each dose-group experienced ≥50% prostate-specific antigen reduction, suggesting clinical benefit from AA in Japanese CRPC patients. AA was generally well-tolerated, and, therefore, the recommended AA dosage regimen in Japanese CRPC patients is 1000 mg oral dose under modified fasting conditions (at least 1 h premeal or 2 h postmeal). This study is registered at ClinicalTrials.gov: NCT01186484. PMID:25117615

  2. Patients' Preferences for the Treatment of Metastatic Castrate-resistant Prostate Cancer: A Discrete Choice Experiment.

    PubMed

    Eliasson, Lina; de Freitas, Hayley M; Dearden, Lindsay; Calimlim, Brian; Lloyd, Andrew J

    2017-04-01

    Patient treatment preferences are increasingly being used to inform health care decision making. This discrete choice experiment assessed how men perceive the risks and benefits of hypothetical treatment options for metastatic castrate-resistant prostate cancer (mCRPC). Treatment attributes for inclusion were identified through a review of the literature and product labels. Expert interviews confirmed clinical appropriateness and patient relevance of the attributes, which included effectiveness (delay in months before chemotherapy), steroid use, possible drug interactions (additional hospital visits for monitoring), fogginess (effects on cognition and memory), fatigue (extreme tiredness), food restrictions, and bone pain. Following a pilot, the final discrete choice experiment included 18 choice sets presenting treatments for mCRPC and was completed by men with mCRPC in France, Germany, and the United Kingdom. Data were analyzed using a conditional logit model, with odds ratios (ORs) used to indicate preference for attributes, and tradeoff measures (TOM) were estimated using the ratio of coefficients. Within each attribute category and with all other factors being equal, participants (N = 285) indicated a strong preference for treatments that fully control bone pain (OR = 12.069 [95% CI, 10.555-13.800]) and for treatments that delay chemotherapy (OR, 1.727 [95% CI, 1.548-1.927]). They also preferred treatments that were associated with the lowest risk of fogginess (OR, 2.115 [95% CI, 1.849-2.420]), a lower risk of fatigue (OR, 1.365 [95% CI 1.219-1.528]), and fewer additional hospital visits (OR, 1.245 [95% CI 1.111-1.397]) than the respective reference categories. Participants preferred to use steroids under advice from a physician (OR, 1.275 [95% CI 1.132-1.437]). Food restrictions related to taking medication were not a significant concern for participants. TOM results indicated that large tradeoffs in effectiveness, fogginess, and fatigue are required for

  3. Budgetary Impact of Cabazitaxel Use After Docetaxel Treatment for Metastatic Castration-Resistant Prostate Cancer.

    PubMed

    Flannery, Kyle; Drea, Ed; Hudspeth, Louis; Corman, Shelby; Gao, Xin; Xue, Mei; Miao, Raymond

    2017-04-01

    With the approval of several new treatments for metastatic castration-resistant prostate cancer (mCRPC), budgetary impact is a concern for health plan decision makers. Budget impact models (BIMs) are becoming a requirement in many countries as part of formulary approval or reimbursement decisions. Cabazitaxel is a second-generation taxane developed to overcome resistance to docetaxel and is approved for the treatment of patients with mCRPC previously treated with a docetaxel-containing regimen. To estimate a 1-year projected budget impact of varying utilization rates of cabazitaxel as a second-line treatment for mCRPC following docetaxel, using a hypothetical U.S. private managed care plan with 1 million members. A BIM was developed to evaluate costs for currently available treatment options for patients with mCRPC previously treated with docetaxel. Treatments included in the model were cabazitaxel, abiraterone acetate, enzalutamide, and radium-223, with utilization rates derived from market research data. Medication costs were calculated according to published pricing benchmarks factored by dosing and duration of therapy as stated in the prescribing information for each agent. Published rates and costs of grade 3-4 adverse events were also factored into the model. In addition, the model reports budget impact under 2 scenarios. In the first base-case scenario, patient out-of-pocket costs were subtracted from the total cost of treatment. In the second scenario, all treatment costs were assumed to be paid by the plan. In a hypothetical 1 million-member health plan population, 100 patients were estimated to receive second-line treatment for mCRPC after treatment with docetaxel. Using current utilization rates for the 4 agents of interest, the base-case scenario estimated the cost of second-line treatment after docetaxel to be $6,331,704, or $0.528 per member per month (PMPM). In a scenario where cabazitaxel use increases from the base-rate case of 24% to a

  4. Gradual reduction of testosterone using a gonadotropin-releasing hormone vaccination delays castration resistance in a prostate cancer model

    PubMed Central

    Barranco, Jesús A. Junco; Millar, Robert P.; Fuentes, Franklin; Bover, Eddy; Pimentel, Eulogio; Basulto, Roberto; Calzada, Lesvia; Morán, Rolando; Rodríguez, Ayni; Garay, Hilda; Reyes, Osvaldo; Castro, Maria D.; Bringas, Ricardo; Arteaga, Niurka; Toudurí, Henio; Rabassa, Mauricio; Fernández, Yairis; Serradelo, Andrés; Hernández, Eduardo; Guillén, Gerardo E.

    2016-01-01

    In a previous study aimed to design a novel prostate cancer vaccine, the authors of the present study demonstrated the advantage of combining the adjuvants Montanide ISA 51 with very small size proteoliposomes (VSSP) to promote a significant humoral immune response to gonadotropin-releasing hormone (GnRH) in healthy animals. The present study compared the efficacy of this vaccine formulation versus the standard treatment currently available in terms of preventing the development of tumors in DD/S mice injected with Shionogi carcinoma (SC) 115 cells. The results demonstrated that 5 non-vaccinated control mice exhibited a fast tumor growth, and succumbed to the disease within 19–31 days. Mice immunized with the GnRH/Montanide ISA 51/VSSP vaccine exhibited a moderate decline in testosterone levels that was associated with a decrease in anti-GnRH antibody titers, which lead to a sustained tumor growth inhibition. In total, 2 mice in the immunized group exhibited complete remission of the tumor for the duration of the present study. In addition, castrated mice, which were used as a control for standard hormonal therapy, exhibited an accelerated decrease in tumor size. However, tumor relapse was observed between days 50 and 54, and between days 65 and 85, following the injection of SC 155 cells. Therefore, these mice were sacrificed at day 90. The present study concludes that the slow and moderate reduction of testosterone levels observed using the GnRH-based vaccine may delay the appearance of castration resistance in a Shionogi prostate cancer model. These findings suggest that this vaccine may be used to delay castration resistance in patients with prostate cancer. PMID:27446378

  5. Gradual reduction of testosterone using a gonadotropin-releasing hormone vaccination delays castration resistance in a prostate cancer model.

    PubMed

    Barranco, Jesús A Junco; Millar, Robert P; Fuentes, Franklin; Bover, Eddy; Pimentel, Eulogio; Basulto, Roberto; Calzada, Lesvia; Morán, Rolando; Rodríguez, Ayni; Garay, Hilda; Reyes, Osvaldo; Castro, Maria D; Bringas, Ricardo; Arteaga, Niurka; Toudurí, Henio; Rabassa, Mauricio; Fernández, Yairis; Serradelo, Andrés; Hernández, Eduardo; Guillén, Gerardo E

    2016-08-01

    In a previous study aimed to design a novel prostate cancer vaccine, the authors of the present study demonstrated the advantage of combining the adjuvants Montanide ISA 51 with very small size proteoliposomes (VSSP) to promote a significant humoral immune response to gonadotropin-releasing hormone (GnRH) in healthy animals. The present study compared the efficacy of this vaccine formulation versus the standard treatment currently available in terms of preventing the development of tumors in DD/S mice injected with Shionogi carcinoma (SC) 115 cells. The results demonstrated that 5 non-vaccinated control mice exhibited a fast tumor growth, and succumbed to the disease within 19-31 days. Mice immunized with the GnRH/Montanide ISA 51/VSSP vaccine exhibited a moderate decline in testosterone levels that was associated with a decrease in anti-GnRH antibody titers, which lead to a sustained tumor growth inhibition. In total, 2 mice in the immunized group exhibited complete remission of the tumor for the duration of the present study. In addition, castrated mice, which were used as a control for standard hormonal therapy, exhibited an accelerated decrease in tumor size. However, tumor relapse was observed between days 50 and 54, and between days 65 and 85, following the injection of SC 155 cells. Therefore, these mice were sacrificed at day 90. The present study concludes that the slow and moderate reduction of testosterone levels observed using the GnRH-based vaccine may delay the appearance of castration resistance in a Shionogi prostate cancer model. These findings suggest that this vaccine may be used to delay castration resistance in patients with prostate cancer.

  6. Radium-223 dichloride: a novel treatment option for castration-resistant prostate cancer patients with symptomatic bone metastases.

    PubMed

    McGann, Shane; Horton, Evan R

    2015-04-01

    To review and evaluate the clinical trial efficacy and safety of radium 223 ((223)Ra) along with its place in therapy in men with castration-resistant prostate cancer (CRPC). A literature search in PubMed/MEDLINE (up to October 2014) was performed using various combinations of the terms radium, hormone-refractory prostate cancer, and castration-resistant prostate cancer. The New Drug Application Medical, Pharmacology, and Clinical Pharmacology and Biopharmaceutics Reviews for radium (223)Ra dichloride were also utilized. The bibliographies of articles were reviewed to identify additional references. Phase 1, 2, and 3 studies that assessed the safety and/or efficacy of (223)Ra in patients with CRPC were reviewed. Peer-reviewed articles with clinically relevant information were reviewed for background information. In May 2013, the Food and Drug Administration approved intravenous use of (223)Ra for the treatment of patients with CRPC, symptomatic bone metastases, and no known visceral metastatic disease. In a phase 3 study comparing (223)Ra and the best standard of care (SOC) versus the best SOC plus placebo, (223)Ra was shown to increase survival. The most commonly seen adverse drug reactions and hematological laboratory abnormalities with (223)Ra include nausea, diarrhea, vomiting, peripheral edema, anemia, lymphocytopenia, leukopenia, thrombocytopenia, and neutropenia. (223)Ra is a first-in-class α-particle-emitting radioactive agent that is first-line therapy, providing an extra option for men suffering from CRPC with symptomatic bone metastases and no known visceral metastases. (223)Ra has also been shown to be relatively well tolerated when up to 6 injections are given. Further studies are needed to evaluate whether (223)Ra is safe and effective for more than 6 doses and if it can be used concomitantly with chemotherapy. © The Author(s) 2015.

  7. Practice patterns and predictors of followup imaging after a negative bone scan in men with castration resistant prostate cancer: results from the SEARCH database.

    PubMed

    Sourbeer, Katharine N; Howard, Lauren E; Moreira, Daniel M; Amarasekara, Hiruni S; Chow, Lydia D; Cockrell, Dillon C; Hanyok, Brian T; Pratson, Connor L; Kane, Christopher J; Terris, Martha K; Aronson, William J; Cooperberg, Matthew R; Amling, Christopher L; Hernandez, Rohini K; Freedland, Stephen J

    2015-04-01

    We investigated imaging practice patterns in men with nonmetastatic (M0) castration resistant prostate cancer. We analyzed data on 247 patients with documented M0 CRPC from the SEARCH database. Patients were selected regardless of primary treatment modality and all had a negative bone scan after a castration resistant prostate cancer diagnosis. Cox models were used to test associations of time to a second imaging test with several demographic and clinical factors. During a median followup of 29.0 months (IQR 12.9-43.5) after a post-castration resistant prostate cancer bone scan was negative, 190 patients (77%) underwent a second imaging test. On univariable analysis patients with higher prostate specific antigen (HR 1.13, p = 0.016), shorter prostate specific antigen doubling time (HR 0.79, p < 0.001) and faster prostate specific antigen velocity (HR 1.01, p < 0.001) were more likely to undergo a second imaging test. Treatment center was also a significant predictor of a second imaging test (p = 0.010). No other factor was a significant predictor. Results were similar on multivariable analysis. It was estimated that approximately 20% of men with a prostate specific antigen doubling time of less than 3 months did not undergo an imaging test in the first year after a post-castration resistant prostate cancer negative bone scan. However, 50% of patients with prostate specific antigen doubling time 15 months or greater underwent a second imaging test in the first year. Clinicians use some known predictors of positive imaging tests to determine which patients with M0 castration resistant prostate cancer undergo a second imaging test . However, there may be under imaging in those at high risk and over imaging in those at low risk. Further studies are needed to identify risk factors for metastasis and form clear imaging guidelines in patients with M0 castration resistant prostate cancer. Copyright © 2015 American Urological Association Education and Research, Inc

  8. (177)Lu-DKFZ-PSMA-617 therapy in metastatic castration resistant prostate cancer: safety, efficacy, and quality of life assessment.

    PubMed

    Yadav, Madhav Prasad; Ballal, Sanjana; Tripathi, Madhavi; Damle, Nishikant Avinash; Sahoo, Ranjit Kumar; Seth, Amlesh; Bal, Chandrasekhar

    2017-01-01

    The purpose of this study was to evaluate the efficacy and safety of a novel theranostic agent, (177)Lu-DKFZ-PSMA-617 therapy in metastatic castration resistant prostate cancer (mCRPC). Thirty-one mCRPC patients with progressive disease despite second-line hormonal therapy and/or docetaxel chemotherapy were recruited for the study. All patients underwent diagnostic(68)Ga-PSMA-HBED-CCPET/CT, prior to inclusion for therapy. Included patients then underwent quarterly (177)Lu-DKFZ-PSMA-617 therapy. Hematological, kidney function, liver function tests, and serum PSA levels were recorded before and after therapy at 2 weeks, 4 weeks, and 3 month intervals. Biochemical response was assessed with trend in serum PSA levels. Metabolic response was assessed by PERCIST 1 criteria. Clinical response was assessed by visual analogue score (VASmax) analgesic score (AS), Karanofsky performance status (KPS), and ttoxicity and response criteria of the Eastern Cooperative Oncology Group (ECOG) criteria. The mean age of patients was 65.93 ± 9.77 years (range: 38-81 years). The mean activity administered in the 31 patients was 5069 ± 1845 MBq ranging from one to four cycles. There was a decline in the mean serum PSA levels from the baseline (baseline: 275 ng/mL, post 1st cycle therapy: 141.75 ng/mL). Based on biochemical response criteria 2/31, 20/31, 3/31, and 6/31 had complete response (CR), partial response(PR), stable disease (SD), and progressive disease (PD), respectively. Metabolic response revealed 2/6 patients with CR, and the remaining 3/6 patients with PR and 1/6 patients with SD. The mean VASmax score decreased from 7.5 to 3. The mean analgesic score decreased from 2.5 to 1.8 after therapy. The mean KPS score improved from 50.32 to 65.42 after therapies. The mean ECOG performance status improved from 2.54 to 1.78 after therapy. Two patients experienced grade I and grade II hemoglobin toxicity each. None of the patients experienced nephrotoxicity or

  9. State-of-the-Art Management for the Patient with Castration-Resistant Prostate Cancer in 2012.

    PubMed

    Sartor, Oliver

    2012-01-01

    Much progress has been made in metastatic castration-resistant prostate cancer (CRPC), and multiple new U.S. Food and Drug Administration (FDA)-approved survival-prolonging drugs are now available. In 2004, docetaxel/prednisone was the first therapy shown to prolong survival. In 2010 and 2011, sipuleucel-T, cabazitaxel/prednisone, and abiraterone/prednisone were FDA approved. Two new agents, radium-223 and MDV-3100, have recently reported large phase III trials prolonging overall survival and will be submitted for regulatory approval in 2012. One can now begin to ask, is there an optimal sequence for therapies in metastatic CRPC? Despite the recent progress, there is much we do not know and virtually no information on this important question. We know that abiraterone/prednisone and cabazitaxel/prednisone are appropriate choices for a patient after receiving docetaxel, but we do not know what, if anything, represents the optimal sequence for abiraterone and cabazitaxel. In fact we do not understand how one therapy may affect the response to a subsequent therapy. We are also aware that the pre- and postdocetaxel spaces represent regulatory rather than biologic divisions. In addition, despite the proven role of docetaxel/prednisone, many patients with CRPC are not considered to be suitable for chemotherapy, and worldwide many never receive any form of chemotherapy. What is the optimal management for these patients? Taken together it is reasonable to assess patient preferences, prior therapies and response/tolerance to prior therapies, burden of disease, comorbidities, current symptoms, drug toxicities, out-of-pocket costs, etc., in clinical decision making. Given the many factors we do not know, it is hard to be dogmatic in approaching the therapeutic options for the patient with CRPC. We will likely soon move beyond the current sequencing paradigm and begin to assess new combinations in a systematic and rational fashion. Perhaps one day, in the not too distant future

  10. Sipuleucel-T immunotherapy for castration-resistant prostate cancer. A systematic review and meta-analysis

    PubMed Central

    Paszulewicz, Anna; Holko, Przemysław; Pilc, Andrzej

    2012-01-01

    Introduction Sipuleucel-T is a novel active cellular immunotherapy for the treatment of asymptomatic or minimally symptomatic metastatic castrate-resistant prostate cancer (mCRPC). It is assumed to be associated with less adverse events than conventional docetaxel-based chemotherapy. Material and methods A systematic review of literature published between January, 1 1966 and February, 6 2012 was performed to assess the efficacy and safety of sipuleucel-T in patients with mCRPC. Databases were searched: Medline, EMBASE, Cochrane, CancerLit as well as ASCO and ESCO websites. Results Three randomized clinical trials with a total of 737 participants fulfilled established criteria. The overall survival of patients who received sipuleucel-T in comparison to the control group was significantly longer with a hazard ratio (HR) of 0.73 (95% CI: 0.61-0.88; p = 0.001). Time to disease progression was not prolonged using sipuleucel-T compared to placebo, HR = 0.89 (95% CI: 0.75-1.05; p = 0.18). Relative benefit (RB) of serum PSA level reduction of at least 50% for sipuleucel-T compared to placebo did not meet statistical significance, RB = 1.97 (95% CI: 0.48-8.14; p = 0.38). The safety population consisted of 729 patients with mCRPC. Compared to the control group, the pooled relative risks (RR) of all adverse events – RR = 1.03 (95% CI: 1.00-1.05; p = 0.06), grade 3 to 5 adverse events – RR = 0.98 (95% CI: 0.79-1.22; p = 0.86) and cerebrovascular events – RR = 1.93 (95% CI: 0.73-5.09; p = 0.18) were not significantly higher for men treated with sipuleucel-T. Conclusions The use of sipuleucel-T prolonged the overall survival among men with mCRPC. No effect on time to disease progression was observed and the safety profile was acceptable. PMID:23185184

  11. YAP1 and AR interactions contribute to the switch from androgen-dependent to castration-resistant growth in prostate cancer

    PubMed Central

    Kuser-Abali, Gamze; Alptekin, Ahmet; Lewis, Michael; Garraway, Isla P.; Cinar, Bekir

    2017-01-01

    The transcriptional co-activator Yes-associated protein 1 (YAP1), a key nuclear effector of the Hippo pathway, is a potent oncogene, and yet, the interaction between YAP1 and androgen receptor (AR) remains unexplored. Here we identify YAP1 as a physiological binding partner and positive regulator of AR in prostate cancer. YAP1 and AR co-localize and interact with each other predominantly within cell nuclei by an androgen-dependent mechanism in a hormone naive and an androgen-independent mechanism in castration-resistant prostate cancer cells. The growth suppressor MST1 kinase modulates androgen-dependent and -independent nuclear YAP1–AR interactions through directly regulating YAP1 nuclear accumulation. Disruption of YAP1 signalling by genetic (RNAi) and pharmacological (Verteporfin) approaches suppresses AR-dependent gene expression and prostate cancer cell growth. These findings indicate that the YAP1–AR axis may have a critical role in prostate cancer progression and serves as a viable drug target. PMID:28230103

  12. The Rationale for Optimal Combination Therapy With Sipuleucel-T for Patients With Castration-resistant Prostate Cancer.

    PubMed

    Mouraviev, Vladimir; Mariados, Neil; Albala, David; Concepcion, Raoul S; Shore, Neal D; Sims, Robert B; Emberton, Mark; Pieczonka, Christopher M

    2014-01-01

    Immunotherapy encourages the recipient's own immune response to destroy cancer cells, and current evidence suggests that immunotherapies may be most beneficial in early metastatic castration-resistant prostate cancer (mCRPC). Sipuleucel-T is the first therapeutic cancer vaccine to be approved by both the US Food and Drug Administration and European Medicines Agency for the treatment of asymptomatic or minimally symptomatic mCRPC. Combining immunotherapy with other treatments may have potent anticancer effects; cytoreductive therapies can release tumor antigens and promote a proinflammatory environment that could augment immunotherapies. However, some cytoreductive agents or coadministered drugs may be immunosuppressive. Understanding these interactions between different mCRPC treatment modalities may offer further potential to improve patient outcomes.

  13. Saracatinib as a metastasis inhibitor in metastatic castration-resistant prostate cancer: A University of Chicago Phase 2 Consortium and DOD/PCF Prostate Cancer Clinical Trials Consortium Study.

    PubMed

    Posadas, Edwin M; Ahmed, Rafi S; Karrison, Theodore; Szmulewitz, Russell Z; O'Donnell, Peter H; Wade, James L; Shen, James; Gururajan, Murali; Sievert, Margarit; Stadler, Walter M

    2016-02-15

    Fyn is a kinase that is upregulated in a subset of metastatic castration-resistant prostate cancer. Saracatinib potently inhibits Fyn activation. We have noted a relationship between Fyn expression and directional motility, a cellular process related to metastasis. As such we hypothesized that treatment with saracatinib would increase the time required to develop new metastatic lesions. Patients with metastatic castration-resistant prostate cancer that had progressed after docetaxel were eligible for enrollment. This study was executed as a randomized discontinuation trial. During a lead-in phase of two 28-Day cycles, all patients received saracatinib. Afterward, patients with radiographically stable disease were randomized to either saracatinib or placebo. Patients continued treatment until evidence of new metastasis. Thirty-one patients were treated. Only 26% of patients had stable disease after 8 weeks and thus proceeded to randomization. This required early termination of the study for futility. The 70% of patients who progressed after the lead-in phase exhibited expansion of existing lesions or decompensation due to clinical progression without new metastatic lesions. Fatigue was reported in more than 25% of patients (all grades) with only two patients experiencing grade 3 toxicity. Other grade 3 adverse events included dehydration, thrombocytopenia, and weakness. This study was unable to determine if saracatinib had potential as metastasis inhibitor. Metastasis inhibition by saracatinib may still be viable in an earlier time in the disease history. © 2015 Wiley Periodicals, Inc.

  14. The 5α-androstanedione pathway to dihydrotestosterone in castration-resistant prostate cancer

    PubMed Central

    Sharifi, Nima

    2011-01-01

    The survival and progression of prostate cancer is generally dependent on expression of the androgen receptor (AR), as well as the availability of endogenous AR agonists. Originating from the gonads, testosterone is released into circulation and is converted by steroid-5α-reductase (SRD5A) in prostate cancer to 5α-dihydrotestosterone (DHT), potently activating AR and driving tumor progression. Advanced prostate cancer is initially treated with gonadal testosterone depletion, which suppresses this cascade of events and typically leads to a treatment response. Eventually, resistance to testosterone deprivation occurs with “castration-resistant” prostate cancer (CRPC) and is driven by the intratumoral synthesis of DHT. The generation of DHT occurs in large part from adrenal 19-carbon precursor steroids, which are dependent on expression of CYP17A1. Although the path from adrenal precursor steroids to DHT was generally thought to require 5α-reduction of testosterone, recent data suggest that it instead involves conversion from Δ4-androstenedione by SRD5A isoenzyme-1 to 5α-androstanedione, followed by subsequent conversion to DHT. The 5α-androstanedione pathway to DHT therefore bypasses testosterone entirely. Abiraterone acetate effectively inhibits CYP17A1, blocks the synthesis of androgens and extends the survival of men with CRPC. Further progress in the hormonal treatment of CRPC is dependent on an understanding of the mechanisms that underlie CRPC and resistance to abiraterone acetate. PMID:22064602

  15. Molecular profiling of peripheral blood is associated with circulating tumor cells content and poor survival in metastatic castration-resistant prostate cancer.

    PubMed

    Marín-Aguilera, Mercedes; Reig, Òscar; Lozano, Juan José; Jiménez, Natalia; García-Recio, Susana; Erill, Nadina; Gaba, Lydia; Tagliapietra, Andrea; Ortega, Vanesa; Carrera, Gemma; Colomer, Anna; Gascón, Pedro; Mellado, Begoña

    2015-04-30

    The enumeration of circulating tumor cells (CTCs) in peripheral blood correlates with clinical outcome in castration-resistant prostate cancer (CRPC). We analyzed the molecular profiling of peripheral blood from 43 metastatic CRPC patients with known CTC content in order to identify genes that may be related to prostate cancer progression. Global gene expression analysis identified the differential expression of 282 genes between samples with ≥5 CTCs vs <5 CTCs, 58.6% of which were previously described as over-expressed in prostate cancer (18.9% in primary tumors and 56.1% in metastasis). Those genes were involved in survival functions such as metabolism, signal transduction, gene expression, cell growth, death, and movement. The expression of selected genes was evaluated by quantitative RT-PCR. This analysis revealed a two-gene model (SELENBP1 and MMP9) with a high significant prognostic ability (HR 6; 95% CI 2.61 - 13.79; P<0.0001). The combination of the two-gene signature plus the CTCs count showed a higher prognostic ability than CTCs enumeration or gene expression alone (P<0.05). This study shows a gene expression profile in PBMNC associated with CTCs count and clinical outcome in metastatic CRPC, describing genes and pathways potentially associated with CRPC progression.

  16. Molecular profiling of peripheral blood is associated with circulating tumor cells content and poor survival in metastatic castration-resistant prostate cancer

    PubMed Central

    Marín-Aguilera, Mercedes; Reig, Òscar; Lozano, Juan José; Jiménez, Natalia; García-Recio, Susana; Erill, Nadina; Gaba, Lydia; Tagliapietra, Andrea; Ortega, Vanesa; Carrera, Gemma; Colomer, Anna; Gascón, Pedro; Mellado, Begoña

    2015-01-01

    The enumeration of circulating tumor cells (CTCs) in peripheral blood correlates with clinical outcome in castration-resistant prostate cancer (CRPC). We analyzed the molecular profiling of peripheral blood from 43 metastatic CRPC patients with known CTC content in order to identify genes that may be related to prostate cancer progression. Global gene expression analysis identified the differential expression of 282 genes between samples with ≥5 CTCs vs <5 CTCs, 58.6% of which were previously described as over-expressed in prostate cancer (18.9% in primary tumors and 56.1% in metastasis). Those genes were involved in survival functions such as metabolism, signal transduction, gene expression, cell growth, death, and movement. The expression of selected genes was evaluated by quantitative RT-PCR. This analysis revealed a two-gene model (SELENBP1 and MMP9) with a high significant prognostic ability (HR 6; 95% CI 2.61 - 13.79; P<0.0001). The combination of the two-gene signature plus the CTCs count showed a higher prognostic ability than CTCs enumeration or gene expression alone (P<0.05). This study shows a gene expression profile in PBMNC associated with CTCs count and clinical outcome in metastatic CRPC, describing genes and pathways potentially associated with CRPC progression. PMID:25871394

  17. Phase II study of single-agent orteronel (TAK-700) in patients with nonmetastatic castration-resistant prostate cancer and rising prostate-specific antigen.

    PubMed

    Hussain, Maha; Corn, Paul G; Michaelson, M Dror; Hammers, Hans J; Alumkal, Joshi J; Ryan, Charles J; Bruce, Justine Y; Moran, Susan; Lee, Shih-Yuan; Lin, H Mark; George, Daniel J

    2014-08-15

    Orteronel (TAK-700) is an investigational, nonsteroidal, oral, inhibitor of androgen synthesis with greater specificity for 17,20-lyase than for 17α-hydroxylase. We investigated orteronel without steroids in patients with nonmetastatic castration-resistant prostate cancer (nmCRPC; M0). Patients with nmCRPC and rising prostate-specific antigen (PSA) received orteronel 300 mg twice daily until PSA progression, metastases, or unacceptable toxicity. The primary endpoint was percentage of patients achieving PSA ≤0.2 ng/mL (undetectable levels) at 3 months. Secondary endpoints included safety, PSA response, time to metastases, and correlated endpoints. Thirty-nine patients with a median baseline PSA doubling time of 2.4 months (range, 0.9-9.2) received a median of fourteen 28-day treatment cycles. PSA decreased >30% in 35 patients and 6 (16%) achieved PSA ≤ 0.2 ng/mL at 3 months. Median times to PSA progression and metastasis were 13.8 and 25.4 months, respectively. Kaplan-Meier estimates of freedom from PSA progression were 57% and 42% at 12 and 24 months, and of freedom from metastasis were 94% and 62% at 12 and 24 months, respectively. At 3 months, median testosterone declined by 89% from baseline. Adverse events led to therapy discontinuation in 12 patients and grade ≥3/4 adverse events occurred in 22 patients. Most frequent all-cause adverse events included fatigue (64%), hypertension (44%), diarrhea (38%), and nausea (33%), which were primarily grade 1/2. Single-agent orteronel produced marked and durable declines in PSA in patients with nmCRPC. Orteronel has moderate but manageable toxicities and its chronic administration without steroids appears feasible. ©2014 American Association for Cancer Research.

  18. Pain, PSA flare, and bone scan response in a patient with metastatic castration-resistant prostate cancer treated with radium-223, a case report.

    PubMed

    McNamara, Megan A; George, Daniel J

    2015-05-07

    Radium-223 has been shown to improve overall survival in men with metastatic castration-resistant prostate cancer with symptomatic bone metastases. The bone scan response to radium-223 has only been described in one single center trial of 14 patients, none of whom achieved the outstanding bone scan response presented in the current case. In this case report, we describe a 75 year-old white man with extensively pre-treated metastatic castration-resistant prostate cancer and symptomatic bone metastases who experienced a flare in pain and prostate-specific antigen, followed by dramatic clinical (pain), biochemical (prostate-specific antigen), and imaging (bone scan) response. The flare phenomena and bone scan response we observed have not previously been described with radium-223. This case suggests that the degree and duration of bone scan response may be predictive of overall survival benefit.

  19. Impact of a pharmacist-led oral chemotherapy-monitoring program in patients with metastatic castrate-resistant prostate cancer.

    PubMed

    Patel, Jay M; Holle, Lisa M; Clement, Jessica M; Bunz, Thomas; Niemann, Christopher; Chamberlin, Kevin W

    2016-12-01

    With the introduction of oral chemotherapy, the paradigm for cancer treatment is shifting. Use of oral chemotherapy agents offers a non-invasive option for patients with metastatic castrate-resistant prostate cancer. However, these medications are not without challenges including strict adherence for optimal effects, novel toxicity profiles, frequent lab parameter monitoring, high cost, and proper handling and disposal methods. Pharmacists are positioned to play a key role in providing patients with the education required to assure an optimal treatment course is carried out. Two cohorts of patients receiving abiraterone, bicalutamide, or enzalutamide for metastatic castrate-resistant prostate cancer seen in our outpatient cancer center 21 months before and 24 months after the implementation of a pharmacist-led oral chemotherapy-monitoring program in December of 2012 were retrospectively compared. Patients were evaluated for number of interventions, adherence to lab parameter monitoring, and overall time on each therapy. Of the 64 patients identified, 31 patients fulfilled inclusion criteria. A significant increase in the average number of interventions per patient (6.9 vs. 2.6; P = 0.004) and adherence to lab parameter monitoring (10 vs. 3; P = 0.04) in the post-program implementation cohort was found. However, no significant difference in overall time on therapy (10.3 vs. 8.1; P = 0.341) between the two groups was observed. These results suggest a potential opportunity exists to maximize oral chemotherapy treatment outcomes with the addition of a formalized monitoring program directed by an oncology pharmacist. © The Author(s) 2015.

  20. Differences in Trial and Real-world Populations in the Dutch Castration-resistant Prostate Cancer Registry.

    PubMed

    Westgeest, Hans M; Uyl-de Groot, Carin A; van Moorselaar, Reindert J A; de Wit, Ronald; van den Bergh, Alphonsus C M; Coenen, Jules L L M; Beerlage, Harrie P; Hendriks, Mathijs P; Bos, Monique M E M; van den Berg, Pieter; van de Wouw, Agnes J; Spermon, Roan; Boerma, Michiel O; Geenen, Maud M; Tick, Lidwine W; Polee, Marco B; Bloemendal, Haiko J; Cordia, Igor; Peters, Frank P J; de Vos, Aad I; van den Bosch, Joan; van den Eertwegh, Alphonsus J M; Gerritsen, Winald R

    2016-10-13

    Trials in castration-resistant prostate cancer (CRPC) treatment have shown improved outcomes, including survival. However, as trial populations are selected, results may not be representative for the real-world population. The aim of this study was to assess the differences between patients treated in a clinical trial versus standard care during the course of CRPC in a real-world CRPC population. Castration-resistant Prostate Cancer Registry is a population-based, observational, retrospective registry. CRPC patients from 20 hospitals in the Netherlands have been included from 2010 to 2013. Baseline characteristics, systemic treatment, and overall survival were the main outcomes. Descriptive statistics, multivariate Cox regression, and multiple imputations with the Monte Carlo Markov Chain method were used. In total, 1524 patients were enrolled of which 203 patients had participated in trials at any time. The median follow-up period was 23 mo. Patients in the trial group were significantly younger and had less comorbidities. Docetaxel treatment was more frequently used in trial patients (85% vs 40%). Despite an observed unadjusted median overall survival difference of 35 mo versus 24 mo between the trial and standard care group, this difference was not retained after adjustment for baseline characteristics and treatment effect. At CRPC diagnosis, the baseline characteristics of the patients who had been enrolled in trials notably differed from patients who received standard treatment options only. The survival difference between the trial and standard care group could be explained by baseline differences and treatment effects. These results indicate that trial results cannot easily be translated to real-world practice. We observed that patients treated in clinical trials differed from patients who were not. We concluded that this may lead to differential treatment and survival. Caution is warranted when real-world outcomes are compared with trial results. Copyright

  1. Targeting autophagy overcomes Enzalutamide resistance in castration-resistant prostate cancer cells and improves therapeutic response in a xenograft model

    PubMed Central

    Nguyen, H G; Yang, J C; Kung, H-J; Shi, X-B; Tilki, D; Lara, P N; DeVere White, R W; Gao, A C; Evans, C P

    2014-01-01

    Macro-autophagy is associated with drug resistance in various cancers and can function as an adaptive response to maintain cell survival under metabolic stresses, including androgen deprivation. Androgen deprivation or treatment with androgen receptor (AR) signaling inhibitor (ARSI), Enzalutamide (MDV-3100, ENZA) or bicalutamide induced autophagy in androgen-dependent and in castration-resistant CaP (castration-resistant prostate cancer (CRPC)) cell lines. The autophagic cascade triggered by AR blockage, correlated with the increased light chain 3-II/I ratio and ATG-5 expression. Autophagy was observed in a subpopulation of C4-2B cells that developed insensitivity to ENZA after sustained exposure in culture. Using flow cytometry and clonogenic assays, we showed that inhibiting autophagy with clomipramine (CMI), chloroquine or metformin increased apoptosis and significantly impaired cell viability. This autophagic process was mediated by AMP-dependent protein kinase (AMPK) activation and the suppression of mammalian target of rapamycin (mTOR) through Raptor phosphorylation (Serine 792). Furthermore, small interfering RNA targeting AMPK significantly inhibited autophagy and promoted cell death in CaP cells acutely or chronically exposed to ENZA or androgen deprivation, suggesting that autophagy is an important survival mechanism in CRPC. Lastly, in vivo studies with mice orthotopically implanted with ENZA-resistant cells demonstrated that the combination of ENZA and autophagy modulators, CMI or metformin significantly reduced tumor growth when compared with control groups (P<0.005). In conclusion, autophagy is as an important mechanism of resistance to ARSI in CRPC. Antiandrogen-induced autophagy is mediated through the activation of AMPK pathway and the suppression of mTOR pathway. Blocking autophagy pharmacologically or genetically significantly impairs prostate cancer cell survival in vitro and in vivo, implying the therapeutics potential of autophagy inhibitors

  2. Influence of abiraterone acetate on neuroendocrine differentiation in chemotherapy-naive metastatic castration-resistant prostate cancer.

    PubMed

    Dong, Baijun; Fan, Liancheng; Wang, Yanqing; Chi, Chenfei; Ma, Xiaowei; Wang, Rui; Cai, Wen; Shao, Xiaoguang; Pan, Jiahua; Zhu, Yinjie; Shangguan, Xun; Xin, Zhixiang; Hu, Jianian; Xie, Shaowei; Kang, Xiaonan; Zhou, Lixin; Xue, Wei

    2017-05-01

    To determine the influence of abiraterone Acetate (AA) on neuroendocrine differentiation (NED) in patients with chemotherapy-naive metastatic castration-resistant prostate cancer (mCRPC). We conducted an analysis in 115 chemotherapy-naïve mCRPC patients who would be treated with chemotherapy. The serum levels of chromogranin A (CgA), neurone-specific enolase (NSE) were measured in 67 mCRPC patients without AA treatment and 48 patients after the failure of AA treatment, in which these markers were also measured in 34 patients before and after 6 months of AA treatment. Comparative t-test was used to evaluate the serial changes of serum NED markers during AA treatment and univariate and multivariate analyses were performed to test the influence of AA treatment on NED. Serum CgA were NSE were evaluated to be above the upper limit of normal (ULN) in 56 (48.7%) and 29 (25.2%) patients before chemotherapy. In 34 patients with serial evaluation, serum CgA level of 14 patients and NSE of 14 patients increased after the failure of AA treatment. There was no significant difference of NED markers (CgA or NSE variation (P = 0.243) between at baseline and after the failure of AA treatment. Compared with the CgA elevation group in the first 6 months of AA treatment and baseline supranormal CgA group, the CgA decline group, and baseline normal CgA group has a much longer median PSA PFS (14.34 vs 10.00 months, P < 0.001, and 14.23 vs 10.30 months, P = 0.02) and rPFS, respectively (18.33 vs 11.37 months, P < 0.001, and 17.10 vs 12.07 months, P = 0.03). In logistic univariate analysis, AA treatment and its duration were not independent factors influencing NED. We hypothesized that AA might not significantly lead to progression of NED of mCRPC in general. Furthermore, we found there was heterogeneity in changes of NED markers in different mCRPC patients during AA treatment. Serial CgA and NSE evaluation might help clinicians guide clinical treatment of m

  3. Survival Outcomes of Concurrent Treatment with Docetaxel and Androgen Deprivation Therapy in Metastatic Castration-Resistant Prostate Cancer

    PubMed Central

    Jang, Ho Seong; Koo, Kyo Chul; Cho, Kang Su

    2016-01-01

    Purpose Docetaxel-based chemotherapy (DTX) improves overall survival (OS) of men with metastatic castration-resistant prostate cancer (mCRPC). Considering the potential existence of androgen receptors that remain active at this stage, we aimed to assess the impact of the combined use of androgen deprivation therapy (ADT) with DTX for mCRPC. Materials and Methods We performed a single-institutional retrospective analysis of patients with mCRPC who received either DTX alone (DTX group, n=21) or concurrent DTX and ADT (DTX+ADT group, n=26) between August 2006 and February 2014. All patients received DTX doses of 75 mg/m2 every three weeks for at least three cycles. In the DTX+ADT group, all patients used luteinizing hormone releasing hormone agonist continuously as a concurrent ADT. Results The median follow-up period was 24.0 months (interquartile range 12.0–37.0) for the entire cohort. The median radiographic progression-free survival (rPFS) was 9.0 months and 6.0 months in the DTX+ADT and DTX groups, respectively (log-rank p=0.036). On multivariable Cox regression analysis, concurrent administration of ADT was the only significant predictor of rPFS [hazard ratio (HR)=0.525, 95% confidence intervals (CI) 0.284–0.970, p=0.040]. The median OS was 42.0 and 38.0 months in the DTX+ADT and DTX groups, respectively (log-rank p=0.796). On multivariable analysis, hemoglobin level at the time of DTX initiation was associated with OS (HR=0.532, 95% CI 0.381–0.744, p<0.001). Conclusion In chemotherapy-naive patients with mCRPC, the combined use of ADT with DTX improved rPFS. Our result suggests that the concurrent administration of ADT and DTX is superior to DTX alone. PMID:27401636

  4. Sustained complete response to CTLA-4 blockade in a patient with metastatic, castration-resistant prostate cancer.

    PubMed

    Graff, Julie N; Puri, Sachin; Bifulco, Carlo B; Fox, Bernard A; Beer, Tomasz M

    2014-05-01

    We present the case of a man with metastatic, castration-resistant prostate cancer, who had a complete prostate-specific antigen (PSA) response after 2½ doses of ipilimumab. His treatment course was complicated by diarrhea and autoimmune hepatitis, both of which resolved within 4 months. Sera and biopsy specimens were accessed, and sera from pretreatment and day 113 were analyzed. Augmented antibody responses were detected against 11 potential tumor antigens, with responses ranging from 5- to 20-fold in day 113 sera compared with baseline. Genes that were targets of a strong antibody response (arbitrarily set at 10-fold or greater increase) were analyzed by real-time PCR for expression in the tumor biopsy cDNA. Of the top 5 genes, only 3-hydroxyisobutyryl-CoA hydrolase (HIBCH) could be identified in the amplified tumor biopsy cDNA. Using an antibody to HIBCH, immunohistochemical analysis documented strong expression of the protein. Together, these data suggest that an augmented antibody response to HIBCH, an antigen that was expressed by the patient's prostate cancer, could have contributed to the clinical response. After 16 months of PSA stability, he discontinued his androgen-suppression therapy. With the return of his testosterone, his PSA increased slightly, likely originating from his intact prostate. He has been disease free for the past 6 years without any additional therapy.

  5. Activation of AMPKα mediates additive effects of solamargine and metformin on suppressing MUC1 expression in castration-resistant prostate cancer cells

    PubMed Central

    Xiang, SongTao; Zhang, QiuHong; Tang, Qing; Zheng, Fang; Wu, JingJing; Yang, LiJun; Hann, Swei Sunny

    2016-01-01

    Prostate cancer is the second most common cause of cancer-related deaths worldwide. The mucin 1 (MUC1) oncoprotein is highly expressed in human prostate cancers with aggressive features. However, the role for MUC1 in occurrence and progression of castration-resistant prostate cancer (CRPC) remained elusive. In this study, we showed that solamargine, a major steroidal alkaloid glycoside, inhibited the growth of CRPC cells, which was enhanced in the presence of metformin. Furthermore, we found that solamargine increased phosphorylation of AMPKα, whereas reducing the protein expression and promoter activity of MUC1. A greater effect was observed in the presence of metformin. In addition, solamargine reduced NF-κB subunit p65 protein expression. Exogenously expressed p65 resisted solamargine-reduced MUC1 protein and promoter activity. Interestingly, exogenously expressed MUC1 attenuated solamargine-stimulated phosphorylation of AMPKα and, more importantly reversed solamargine-inhibited cell growth. Finally, solamargine increased phosphorylation of AMPKα, while inhibiting MUC1, p65 and tumor growth were observed in vivo. Overall, our results show that solamargine inhibits the growth of CRPC cells through AMPKα-mediated inhibition of p65, followed by reduction of MUC1 expression in vitro and in vivo. More importantly, metformin facilitates the antitumor effect of solamargine on CRPC cells. PMID:27830724

  6. Hypoxic Tumor Kinase Signaling Mediated by STAT5A in Development of Castration-Resistant Prostate Cancer

    PubMed Central

    Røe, Kathrine; Bratland, Åse; Vlatkovic, Ljiljana; Ragnum, Harald Bull; Saelen, Marie Grøn; Olsen, Dag Rune; Marignol, Laure; Ree, Anne Hansen

    2013-01-01

    In this study, we hypothesized that androgen-deprivation therapy (ADT) in prostate cancer, although initially efficient, induces changes in the tumor kinome, which subsequently promote development of castration-resistant (CR) disease. Recognizing the correlation between tumor hypoxia and poor prognosis in prostate cancer, we further hypothesized that such changes might be influenced by hypoxia. Microarrays with 144 kinase peptide substrates were applied to analyze CWR22 prostate carcinoma xenograft samples from ADT-naïve, androgen-deprived (AD), long-term AD (ADL), and CR disease stages. The impact of hypoxia was assessed by matching the xenograft kinase activity profiles with those acquired from hypoxic and normoxic prostate carcinoma cell cultures, whereas the clinical relevance was evaluated by analyzing prostatectomy tumor samples from patients with locally advanced disease, either in ADT-naïve or early CR disease stages. By using this novel peptide substrate microarray method we revealed high kinase activity mediated by signal transducer and activator of transcription 5A (STAT5A) in CR prostate cancer. Additionally, we uncovered high STAT5A kinase activity already in regressing ADL xenografts, before renewed CR growth was evidenced. Finally, since increased STAT5A kinase activity also was detected after exposing prostate carcinoma cells to hypoxia, we propose long-term ADT to induce tumor hypoxia and stimulate STAT5A kinase activity, subsequently leading to renewed CR tumor growth. Hence, the study detected STAT5A as a candidate to be further investigated for its potential as marker of advanced prostate cancer and as possible therapeutic target protein. PMID:23675504

  7. Hypoxic tumor kinase signaling mediated by STAT5A in development of castration-resistant prostate cancer.

    PubMed

    Røe, Kathrine; Bratland, Åse; Vlatkovic, Ljiljana; Ragnum, Harald Bull; Saelen, Marie Grøn; Olsen, Dag Rune; Marignol, Laure; Ree, Anne Hansen

    2013-01-01

    In this study, we hypothesized that androgen-deprivation therapy (ADT) in prostate cancer, although initially efficient, induces changes in the tumor kinome, which subsequently promote development of castration-resistant (CR) disease. Recognizing the correlation between tumor hypoxia and poor prognosis in prostate cancer, we further hypothesized that such changes might be influenced by hypoxia. Microarrays with 144 kinase peptide substrates were applied to analyze CWR22 prostate carcinoma xenograft samples from ADT-naïve, androgen-deprived (AD), long-term AD (ADL), and CR disease stages. The impact of hypoxia was assessed by matching the xenograft kinase activity profiles with those acquired from hypoxic and normoxic prostate carcinoma cell cultures, whereas the clinical relevance was evaluated by analyzing prostatectomy tumor samples from patients with locally advanced disease, either in ADT-naïve or early CR disease stages. By using this novel peptide substrate microarray method we revealed high kinase activity mediated by signal transducer and activator of transcription 5A (STAT5A) in CR prostate cancer. Additionally, we uncovered high STAT5A kinase activity already in regressing ADL xenografts, before renewed CR growth was evidenced. Finally, since increased STAT5A kinase activity also was detected after exposing prostate carcinoma cells to hypoxia, we propose long-term ADT to induce tumor hypoxia and stimulate STAT5A kinase activity, subsequently leading to renewed CR tumor growth. Hence, the study detected STAT5A as a candidate to be further investigated for its potential as marker of advanced prostate cancer and as possible therapeutic target protein.

  8. The N-terminal domain of the androgen receptor drives its nuclear localization in castration-resistant prostate cancer cells.

    PubMed

    Dar, Javid A; Masoodi, Khalid Z; Eisermann, Kurtis; Isharwal, Sudhir; Ai, Junkui; Pascal, Laura E; Nelson, Joel B; Wang, Zhou

    2014-09-01

    Androgen-independent nuclear localization is required for androgen receptor (AR) transactivation in castration-resistant prostate cancer (CRPC) and should be a key step leading to castration resistance. However, mechanism(s) leading to androgen-independent AR nuclear localization are poorly understood. Since the N-terminal domain (NTD) of AR plays a role in transactivation under androgen-depleted conditions, we investigated the role of the NTD in AR nuclear localization in CRPC. Deletion mutagenesis was used to identify amino acid sequences in the NTD essential for its androgen-independent nuclear localization in C4-2, a widely used CRPC cell line. Deletion mutants of AR tagged with green fluorescent protein (GFP) at the 5'-end were generated and their signal distribution was investigated in C4-2 cells by fluorescent microscopy. Our results showed that the region of a.a. 294-556 was required for androgen-independent AR nuclear localization whereas a.a. 1-293 mediates Hsp90 regulation of AR nuclear localization in CRPC cells. Although the region of a.a. 294-556 does not contain a nuclear import signal, it was able to enhance DHT-induced import of the ligand binding domain (LBD). Also, transactivation of the NTD could be uncoupled from its modulation of AR nuclear localization in C4-2 cells. These observations suggest an important role of the NTD in AR intracellular trafficking and androgen-independent AR nuclear localization in CRPC cells. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Managing Metastatic Castration-Resistant Prostate Cancer in the Pre-chemotherapy Setting: A Changing Approach in the Era of New Targeted Agents.

    PubMed

    Zafeiriou, Zafeiris; Jayaram, Anuradha; Sharp, Adam; de Bono, Johann S

    2016-03-01

    In recent years, the therapeutic options for treating men with metastatic castration-resistant prostate cancer have increased substantially. The hormonal treatments abiraterone acetate and enzalutamide, the chemotherapeutics docetaxel and cabazitaxel, the radiopharmaceutical alpharadin and the immunotherapeutic Sipuleucel-T have entered the field. Additionally, corticosteroids, which are used extensively, have documented activity but no documented survival benefit. Physicians treating patients with metastatic prostate cancer immediately after castration resistance develops currently have at least four different options to choose from for the first treatment. These therapeutic choices and their several possible ways of sequential use have not yet been compared to each other head-to-head and may never be. Therefore, there is an unmet need to inform their use with prospective clinical data. Additionally, the new indications of docetaxel for hormone naïve prostate cancer is changing the landscape of prostate cancer treatment and questions the traditional classifications 'pre-chemotherapy' and 'post-chemotherapy'. In this work we attempt to address these challenges in the treatment of metastatic castration-resistant prostate cancer with the focus mainly on the non-cytotoxic agents. We try to integrate available clinical and preclinical information to suggest optimal ways of treatment.

  10. Denosumab and bone metastasis-free survival in men with nonmetastatic castration-resistant prostate cancer: exploratory analyses by baseline prostate-specific antigen doubling time.

    PubMed

    Smith, Matthew R; Saad, Fred; Oudard, Stephane; Shore, Neal; Fizazi, Karim; Sieber, Paul; Tombal, Bertrand; Damiao, Ronaldo; Marx, Gavin; Miller, Kurt; Van Veldhuizen, Peter; Morote, Juan; Ye, Zhishen; Dansey, Roger; Goessl, Carsten

    2013-10-20

    Denosumab, an anti-RANK ligand monoclonal antibody, significantly increases bone metastasis-free survival (BMFS; hazard ratio [HR], 0.85; P = .028) and delays time to first bone metastasis in men with nonmetastatic castration-resistant prostate cancer (CRPC) and baseline prostate-specific antigen (PSA) ≥ 8.0 ng/mL and/or PSA doubling time (PSADT) ≤ 10.0 months. To identify men at greatest risk for bone metastasis or death, we evaluated relationships between PSA and PSADT with BMFS in the placebo group and the efficacy and safety of denosumab in men with PSADT ≤ 10, ≤ 6, and ≤ 4 months. A total of 1,432 men with nonmetastatic CRPC were randomly assigned 1:1 to monthly subcutaneous denosumab 120 mg or placebo. Enrollment began February 2006; primary analysis cutoff was July 2010, when approximately 660 men were anticipated to have developed bone metastases or died. In the placebo group, shorter BMFS was observed as PSADT decreased below 8 months. In analyses by shorter baseline PSADT, denosumab consistently increased BMFS by a median of 6.0, 7.2, and 7.5 months among men with PSADT ≤ 10 (HR, 0.84; P = .042), ≤ 6 (HR, 0.77; P = .006), and ≤ 4 months (HR, 0.71; P = .004), respectively. Denosumab also consistently increased time to bone metastasis by PSADT subset. No difference in survival was observed between treatment groups for the overall study population or PSADT subsets. Patients with shorter PSADT are at greater risk for bone metastasis or death. Denosumab consistently improves BMFS in men with shorter PSADT and seems to have the greatest treatment effects in men at high risk for progression.

  11. Zoledronic acid but not somatostatin analogs exerts anti-tumor effects in a model of murine prostatic neuroendocrine carcinoma of the development of castration-resistant prostate cancer.

    PubMed

    Hashimoto, Kohei; Masumori, Naoya; Tanaka, Toshiaki; Maeda, Toshihiro; Kobayashi, Ko; Kitamura, Hiroshi; Hirata, Koichi; Tsukamoto, Taiji

    2013-04-01

    Since neuroendocrine (NE) cells play an important role in the development of castration-resistant prostate cancer (CRPC), target therapy to NE cells should be considered for treating CRPC. We investigated the effects zoledronic acid (ZOL) and two somatostatin analogs (octreotide: SMS, and pasireotide: SOM) on an NE allograft (NE-10) and its cell line (NE-CS), which were established from the prostate of the LPB-Tag 12T-10 transgenic mouse. We examined the in vivo effects of ZOL, SMS and SOM as single agents and their combinations on subcutaneously inoculated NE-10 allografts and the in vitro effects on NE-CS cells. Apoptosis and cell cycle activity were assessed by immunohistochemistry using TdT-mediated dUTP-biotin nick-end labeling (TUNEL) and a Ki-67 antibody, respectively. In vivo growth of NE-10 tumors treated with ZOL, ZOL plus SMS, or ZOL plus SOM was significantly inhibited compared to the control as a consequence of induction of apoptosis and cell cycle arrest. ZOL induced time- and dose-dependent inhibition of in vitro proliferation of NE-CS cells, but the somatostatin analogs (SMS and SOM) did not. ZOL also inhibited migration of NE-CS cells. These effects were caused by inhibition of Erk1/2 phosphorylation via impairment of prenylation of Ras. ZOL, but not SMS or SOM, induced apoptosis and inhibition of proliferation and migration through impaired prenylation of Ras in NE carcinoma models. Our findings support the possibility that ZOL could be used in the early phase for controlling NE cells, which may trigger progression to CRPC. Copyright © 2012 Wiley Periodicals, Inc.

  12. Denosumab and Bone Metastasis–Free Survival in Men With Nonmetastatic Castration-Resistant Prostate Cancer: Exploratory Analyses by Baseline Prostate-Specific Antigen Doubling Time

    PubMed Central

    Smith, Matthew R.; Saad, Fred; Oudard, Stephane; Shore, Neal; Fizazi, Karim; Sieber, Paul; Tombal, Bertrand; Damiao, Ronaldo; Marx, Gavin; Miller, Kurt; Van Veldhuizen, Peter; Morote, Juan; Ye, Zhishen; Dansey, Roger; Goessl, Carsten

    2013-01-01

    Purpose Denosumab, an anti–RANK ligand monoclonal antibody, significantly increases bone metastasis–free survival (BMFS; hazard ratio [HR], 0.85; P = .028) and delays time to first bone metastasis in men with nonmetastatic castration-resistant prostate cancer (CRPC) and baseline prostate-specific antigen (PSA) ≥ 8.0 ng/mL and/or PSA doubling time (PSADT) ≤ 10.0 months. To identify men at greatest risk for bone metastasis or death, we evaluated relationships between PSA and PSADT with BMFS in the placebo group and the efficacy and safety of denosumab in men with PSADT ≤ 10, ≤ 6, and ≤ 4 months. Patients and Methods A total of 1,432 men with nonmetastatic CRPC were randomly assigned 1:1 to monthly subcutaneous denosumab 120 mg or placebo. Enrollment began February 2006; primary analysis cutoff was July 2010, when approximately 660 men were anticipated to have developed bone metastases or died. Results In the placebo group, shorter BMFS was observed as PSADT decreased below 8 months. In analyses by shorter baseline PSADT, denosumab consistently increased BMFS by a median of 6.0, 7.2, and 7.5 months among men with PSADT ≤ 10 (HR, 0.84; P = .042), ≤ 6 (HR, 0.77; P = .006), and ≤ 4 months (HR, 0.71; P = .004), respectively. Denosumab also consistently increased time to bone metastasis by PSADT subset. No difference in survival was observed between treatment groups for the overall study population or PSADT subsets. Conclusion Patients with shorter PSADT are at greater risk for bone metastasis or death. Denosumab consistently improves BMFS in men with shorter PSADT and seems to have the greatest treatment effects in men at high risk for progression. PMID:24043751

  13. CH5137291, an androgen receptor nuclear translocation-inhibiting compound, inhibits the growth of castration-resistant prostate cancer cells.

    PubMed

    Ishikura, Nobuyuki; Kawata, Hiromitsu; Nishimoto, Ayako; Nakamura, Ryo; Tsunenari, Toshiaki; Watanabe, Miho; Tachibana, Kazutaka; Shiraishi, Takuya; Yoshino, Hitoshi; Honma, Akie; Emura, Takashi; Ohta, Masateru; Nakagawa, Toshito; Houjo, Takao; Corey, Eva; Vessella, Robert L; Aoki, Yuko; Sato, Haruhiko

    2015-04-01

    Resistance of prostate cancer to castration is currently an unavoidable problem. The major mechanisms underlying such resistance are androgen receptor (AR) overexpression, androgen-independent activation of AR, and AR mutation. To address this problem, we developed an AR pure antagonist, CH5137291, with AR nuclear translocation-inhibiting activity, and compared its activity and characteristics with that of bicalutamide. Cell lines corresponding to the mechanisms of castration resistance were used: LNCaP-BC2 having AR overexpression and LNCaP-CS10 having androgen-independent AR activation. VCaP and LNCaP were used as hormone-sensitive prostate cancer cells. In vitro functional assay clearly showed that CH5137291 inhibited the nuclear translocation of wild-type ARs as well as W741C- and T877A-mutant ARs. In addition, it acted as a pure antagonist on the transcriptional activity of these types of ARs. In contrast, bicalutamide did not inhibit the nuclear translocation of these ARs, and showed a partial/full agonistic effect on the transcriptional activity. CH5137291 inhibited cell growth more strongly than bicalutamide in VCaP and LNCaP cells as well as in LNCaP-BC2 and LNCaP-CS10 cells in vitro. In xenograft models, CH5137291 strongly inhibited the tumor growth of LNCaP, LNCaP-BC2, and LNCaP-CS10, whereas bicalutamide showed a weaker effect in LNCaP and almost no effect in LNCaP-BC2 and LNCaP-CS10 xenografts. Levels of prostate-specific antigen (PSA) in plasma correlated well with the antitumor effect of both agents. CH5137291 inhibited the growth of LNCaP tumors that had become resistant to bicalutamide treatment. A docking model suggested that CH5137291 intensively collided with the M895 residue of helix 12, and therefore strongly inhibited the folding of helix 12, a cause of AR agonist activity, in wild-type and W741C-mutant ARs. In cynomolgus monkeys, the serum concentration of CH5137291 increased dose-dependently and PSA level decreased 80% at 100 mg/kg. CH

  14. C-reactive protein as an adverse prognostic marker for men with castration-resistant prostate cancer (CRPC): confirmatory results

    PubMed Central

    Prins, Renee C.; Rademacher, Brooks L.; Mongoue-Tchokote, Solange; Alumkal, Joshi J.; Graff, Julie N.; Eilers, Kristine M.; Beer, Tomasz M.

    2010-01-01

    We previously reported that higher serum concentrations of C-reactive protein (CRP) are associated with shorter survival in men with castration-resistant prostate cancer (CRPC). To confirm this finding in an independent data set, we used 119 CRPC patients enrolled in 6 phase II clinical trials and examined the relationship of CRP, alkaline phosphatase, hemoglobin, age, ECOG PS, and prostate specific antigen (PSA) with survival. Median follow-up was 19.7 months (0.9–98.5 months) and 89% have died. After analyzing the form of the risk function using the generalized additive model method, univariate and multivariate Cox proportional hazard models were used to assess associations between baseline individual categorical and continuous variables. Quartiles of CRP were: 1: 0–1.0, 1.1–4.9, 5.0–17.0, and 17.1 to 311 mg/L. In a Cox multivariate model, log2(CRP) (HR 1.106 p=0.013) as well as hemoglobin and alkaline phosphatase were independently associated with survival, confirming that higher CRP is associated with shorter survival in CRPC. Since CRP is a marker of inflammation, this finding suggests that inflammation may play an important role in the natural history of advanced prostate cancer. CRP is a readily measurable biomarker that has the potential to improve prognostic models and should be validated in a prospective clinical trial. PMID:20207556

  15. Pharmacotherapeutic Management of Metastatic, Castration-Resistant Prostate Cancer in the Elderly: Focus on Non-Chemotherapy Agents

    PubMed Central

    Beer, Tomasz M.

    2015-01-01

    In the past 4 years, five new agents have been approved for metastatic, castration-resistant prostate cancer. Four of them are non-chemotherapeutic and generally well tolerated. However, each has toxicities that can negatively impact patients, particularly the elderly. This review covers the epidemiology of prostate cancer in elderly men. It discusses the efficacy data for sipuleucel-T, abiraterone in chemotherapy-naïve patients, enzalutamide in chemotherapy-naïve patients and radium-223 and presents any additional studies done for those over 75 years of age. Disease burden, such as the presence or absence of visceral disease, and comorbid conditions weigh into the selection of therapy and are discussed here. Drug–drug interactions between these agents and other drugs commonly used in the elderly population are also considered. The emerging therapies tasquinimod and ipilimumab are reviewed. With the arrival of so many agents for prostate cancer, selection of the most appropriate agent can be perplexing, particularly because these agents were tested against placebo, not one another. Furthermore, the study population differs significantly from those seen in clinical practice. This review addresses these issues. PMID:25387443

  16. Platinum-Based Chemotherapy for Variant Castrate-Resistant Prostate Cancer

    PubMed Central

    Aparicio, Ana M.; Harzstark, Andrea L.; Corn, Paul G.; Wen, Sijin; Araujo, John C.; Tu, Shi-Ming; Pagliaro, Lance C.; Kim, Jeri; Millikan, Randall E.; Ryan, Charles J.; Tannir, Nizar M.; Zurita, Amado J.; Mathew, Paul; Arap, Wadih; Troncoso, Patricia; Thall, Peter F.; Logothetis, Christopher J.

    2013-01-01

    Purpose Clinical features characteristic of small-cell prostate carcinoma (SCPC), (““anaplastic””) often emerge during the progression of prostate cancer. We sought to determine the efficacy of platinum-based chemotherapy in patients meeting at least one of seven prospectively defined “anaplastic” clinical criteria, including exclusive visceral or predominantly lytic bone metastases, bulky tumor masses, low PSA levels relative to tumor burden or short response to androgen deprivation therapy. Experimental Design A 120-patient phase II trial of frontline carboplatin and docetaxel (CD) and second-line etoposide and cisplatin (EP) was designed to provide reliable clinical response estimates under a Bayesian probability model with early stopping rules in place for futility and toxicity. Results Seventy-four of 113 (65.4%) and 24 of 71 (33.8%) were progression free after 4 cycles of CD and EP, respectively. Median overall survival (OS) was 16 months (95% CI, 13.6-19.0 months). Of the 7 “anaplastic” criteria, bulky tumor mass was significantly associated with poor outcome. Lactic acid dehydrogenase (LDH) strongly predicted for OS and rapid progression. Serum carcinoembryonic antigen (CEA) concentration strongly predicted OS but not rapid progression. Neuroendocrine markers did not predict outcome or response to therapy. Conclusion Our findings support the hypothesis that patients with “anaplastic” prostate cancer are a recognizable subset characterized by a high response rate of short duration to platinum-containing chemotherapies, similar to SCPC. Our results suggest that CEA is useful for selecting therapy in men with CRPC and consolidative therapies to bulky high-grade tumor masses should be considered in this patient population. PMID:23649003

  17. Impact of Enzalutamide Compared with Bicalutamide on Quality of Life in Men with Metastatic Castration-resistant Prostate Cancer: Additional Analyses from the TERRAIN Randomised Clinical Trial.

    PubMed

    Heidenreich, Axel; Chowdhury, Simon; Klotz, Laurence; Siemens, David Robert; Villers, Arnauld; Ivanescu, Cristina; Holmstrom, Stefan; Baron, Benoit; Wang, Fong; Lin, Ping; Shore, Neal D

    2017-04-01

    Improving health-related quality of life (HRQoL) is an important goal in metastatic castration-resistant prostate cancer (mCRPC). To examine the impact of enzalutamide versus bicalutamide on HRQoL in mCRPC. TERRAIN is a multinational, phase 2, randomised, double-blind study in asymptomatic/mildly symptomatic men with mCRPC (ClinicalTrials.gov, NCT01288911). Patients were randomised (1:1) via an interactive voice and web response system to enzalutamide 160mg/d (n=184) or bicalutamide 50mg/d (n=191), with androgen deprivation therapy. HRQoL was assessed using Functional Assessment of Cancer Therapy-Prostate (FACT-P), European Quality of Life 5-Domain Scale (EQ-5D), and Brief Pain Inventory, Short-form questionnaires every 12 wk. Primary and secondary analyses utilised mixed models for repeated measures and pattern mixture models, respectively. At 61 wk, 84 (46%) enzalutamide and 39 (20%) bicalutamide patients in the study were assessed. At 61 wk, changes from baseline favoured enzalutamide versus bicalutamide on three FACT-P domains in mixed models for repeated measures analyses and seven in pattern mixture models analyses. There were no differences in changes for EQ-5D index/visual analogue scale scores. Risk of first deterioration was lower with enzalutamide for FACT-P total (hazard ratio: 0.64, 95% confidence interval: 0.46-0.89, p=0.007), FACT-G total (hazard ratio: 0.70, 95% confidence interval: 0.50-0.98, p=0.04), PCS pain (hazard ratio: 0.74, 95% confidence interval: 0.54-1.00, p=0.048), and EQ-5D index (hazard ratio: 0.66, 95% confidence interval: 0.47-0.93, p=0.02) scores versus bicalutamide. Brief Pain Inventory, Short-form scores increased in both groups. There was no difference in time-to-pain progression. Study limitations include the exploratory nature of the HRQoL analyses, lack of multiple comparisons corrections, and unknown effects of anxiety/depression on HRQoL. In patients with asymptomatic/mildly symptomatic mCRPC, enzalutamide provides HRQo

  18. Pharmacokinetics, Antitumor Activity, and Safety of ODM-201 in Patients with Chemotherapy-naive Metastatic Castration-resistant Prostate Cancer: An Open-label Phase 1 Study.

    PubMed

    Massard, Christophe; Penttinen, Heidi M; Vjaters, Egils; Bono, Petri; Lietuvietis, Vilnis; Tammela, Teuvo L; Vuorela, Annamari; Nykänen, Pirjo; Pohjanjousi, Pasi; Snapir, Amir; Fizazi, Karim

    2016-05-01

    ODM-201 is a novel second-generation androgen receptor inhibitor for the treatment of metastatic castration-resistant prostate cancer (mCRPC). To evaluate the pharmacokinetics of ODM-201 tablet products and preliminary long-term safety, tolerability, and antitumor activity of ODM-201 in chemotherapy-naive men with mCRPC. Thirty patients were enrolled in this open-label phase 1 trial. Patients received a single 600-mg dose of ODM-201 in capsules with food and one 600-mg dose of ODM-201 tablet product (TabA or TabB) with food and in the fasted state in a random order. In the extension, patients received 600mg twice daily ODM-201 taken with food in capsules. We analyzed the pharmacokinetics of ODM-201 tablet formulations. Safety and tolerability were assessed until disease progression or an intolerable adverse event (AE). Antitumor activity was assessed by prostate-specific antigen (PSA) levels and imaging. The capsule:TabA ratio of area under the concentration-time curve from time zero to the last sample at 48h was 1.06 (90% confidence interval [CI], 0.91-1.24); the capsule:TabB ratio was 0.97 (90% CI, 0.82-1.14). At week 12, 25 of 30 patients (83%) had a PSA response (≥50% reduction from baseline). Median time to radiographic progression was 66 wk (95% CI, 41-79). Most common AEs were fatigue (n=4 [13%]) and nausea (n=4 [13%]). The study showed that the tablet formulation of ODM-201 had similar pharmacokinetics compared with the capsule. Treatment with a 600-mg twice daily dose of ODM-201 provided anticancer activity and was well tolerated in men with chemotherapy-naive mCRPC. The findings of this study showed that ODM-201 is well tolerated and provided antitumor activity in chemotherapy-naive patients with metastatic castration-resistant prostate cancer (mCRPC) and that the 300-mg tablet formulation can be used in further clinical studies. A phase 3 trial with ODM-201 600mg twice daily in patients with non-mCRPC is ongoing. Copyright © 2015 European Association

  19. New drugs in the treatment of elderly patients with metastatic castration-resistance prostate cancer.

    PubMed

    Genestreti, Giovenzio; Di Battista, Monica; Cavallo, Giovanna; Brandes, Alba A

    2016-08-03

    Treatment of prostate cancer is continually evolving and new therapies have become available. However, the management of elderly patients is challenging due to their age and comorbidities. Androgen deprivation therapy remains the mainstay treatment of hormonal-sensitive disease. Nevertheless, when disease becomes resistant to castration, docetaxel-based chemotherapy represents the standard rescue therapy irrespective of patient age. Recently, chemotherapeutic agents such as cabazitaxel and hormonal therapies such as abiraterone acetate and enzalutamide have been shown to improve survival in patients with progression of disease before or following docetaxel. This review focuses on the safety and efficacy results of these new drugs in elderly patients.

  20. TMPRSS2-ERG in Blood and Docetaxel Resistance in Metastatic Castration-resistant Prostate Cancer.

    PubMed

    Reig, Òscar; Marín-Aguilera, Mercedes; Carrera, Gemma; Jiménez, Natalia; Paré, Laia; García-Recio, Susana; Gaba, Lydia; Pereira, Maria Verónica; Fernández, Pedro; Prat, Aleix; Mellado, Begoña

    2016-11-01

    TMPRSS2-ERG rearrangement is a genetic alteration exclusive to prostate cancer, associated with taxane resistance in preclinical models. Its detection in blood samples of metastatic resistant prostate cancer (mCRPC) patients may indicate the presence of circulating tumour cells with this genetic alteration and may predict taxane resistance. To test this hypothesis, we evaluated TMPRSS2-ERG expression using quantitative reverse transcription polymerase chain reaction in peripheral blood mononuclear cells and tumour tissue from mCPRC patients treated with taxanes. We examined peripheral blood mononuclear cells from 24 healthy controls, 50 patients treated with docetaxel, and 22 with cabazitaxel. TMPRSS2-ERG was detected in 0%, 16%, and 22.7% of them, respectively. In docetaxel-treated patients TMPRSS2-ERG detection correlated with lower prostatic-specific antigen (PSA) response rate (12.5% vs 68.3%, p=0.005), PSA-progression-free survival (PFS; 3.1 mo vs 7.5 mo, p<0.001), clinical/radiological-PFS (3.1 mo vs 8.2 mo, p<0.001), and it was independently associated with PSA-PFS (hazard ratio 3.7; p=0.009) and clinical/radiological-PFS (hazard ratio 6.3; p<0.001). Moreover, TMPRSS2-ERG also predicted low PSA-PFS to cabazitaxel. At progression, a switch from negative to positive TMPRSS2-ERG was observed in 41% of patients with undetected TMPRSS2-ERG at the baseline sample. Tissue TMPRSS2-ERG expression correlated with lower PSA-PFS (p=0.02) to docetaxel. Our findings support the potential role of TMPRSS2-ERG detection as a biomarker to tailor treatment strategies. Taxanes are the most active chemotherapy agents in metastatic resistant prostate cancer. However, not all patients respond to this therapy. In the present study we show that the detection of TMPRSS2-ERG in blood from metastatic resistant prostate cancer patients predicts resistance to docetaxel and it may be useful to select treatment and to avoid possible toxicities in refractory patients. Copyright © 2016

  1. Efficacy and Safety of Enzalutamide vs Bicalutamide in Younger and Older Patients with Metastatic Castration-resistant Prostate Cancer in the TERRAIN Trial.

    PubMed

    Siemens, D Robert; Klotz, Laurence; Heidenreich, Axel; Chowdhury, Simon; Villers, Arnauld; Baron, Benoit; van Os, Steve; Hasabou, Nahla; Wang, Fong; Lin, Ping; Shore, Neal D

    2017-08-18

    Enzalutamide significantly prolonged median progression-free survival vs bicalutamide in chemotherapy-naïve metastatic castration-resistant prostate cancer in TERRAIN. A post hoc analysis investigated the influence of age on efficacy and safety of enzalutamide vs bicalutamide in this population. Patients were randomized 1:1 to enzalutamide 160 mg/day or bicalutamide 50 mg/day. Progression-free survival, time to prostate-specific antigen progression and safety were analyzed post hoc in younger (<75 years) and older (≥75 years) subgroups. Enzalutamide significantly reduced the risk of disease progression or death vs bicalutamide in patients age <75 (hazard ratio 0.38; 95% confidence interval 0.27-0.52; p <0.0001) and ≥75 (hazard ratio 0.59; 95% confidence interval 0.37-0.92; p = 0.018). Time to prostate-specific antigen progression was also significantly prolonged with enzalutamide vs bicalutamide in both subgroups. Adverse event distribution between treatments was similar in each subgroup, except for (≥5% difference between subgroups) more atrial fibrillation, urinary tract infections, falls and decreased appetite in enzalutamide-treated patients age ≥75; less pain in extremity and hot flush in enzalutamide-treated patients age ≥75; and less back pain and hot flush in bicalutamide-treated patients age ≥75. Grade ≥3 cardiac events were more frequent in both enzalutamide-treated and bicalutamide-treated patients age ≥75 vs <75. Fatigue was more frequent in enzalutamide-treated patients, with similar distributions in both age subgroups. Enzalutamide improved clinical outcomes vs bicalutamide irrespective of age. Increased falls and cardiac events suggest caution when prescribing to older patients (≥75 years) with significant comorbidity. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  2. AR-V7 in Peripheral Whole Blood of Patients with Castration-resistant Prostate Cancer: Association with Treatment-specific Outcome Under Abiraterone and Enzalutamide.

    PubMed

    Seitz, Anna Katharina; Thoene, Silvia; Bietenbeck, Andreas; Nawroth, Roman; Tauber, Robert; Thalgott, Mark; Schmid, Sebastian; Secci, Ramona; Retz, Margitta; Gschwend, Jürgen E; Ruland, Jürgen; Winter, Christof; Heck, Matthias M

    2017-08-14

    It has been demonstrated that androgen receptor splice variant 7 (AR-V7) expression in circulating tumor cells (CTCs) predicts poor treatment response in metastatic castration-resistant prostate cancer (mCRPC) patients treated with abiraterone or enzalutamide. To develop a practical and robust liquid profiling approach for direct quantification of AR-V7 in peripheral whole blood without the need for CTC capture and to determine its potential for predicting treatment response in mCRPC patients. Whole blood samples from a prospective biorepository of 85 mCRPC patients before treatment initiation with abiraterone (n=56) or enzalutamide (n=29) were analyzed via droplet digital polymerase chain reaction. The association of AR-V7 status with prostate-specific antigen (PSA) response defined by PSA decline ≥50% and with PSA-progression-free survival (PSA-PFS), clinical PFS, and overall survival (OS) was assessed. High AR-V7 expression levels in whole blood were detectable in 18% (15/85) of patients. No patient with high AR-V7 expression achieved a PSA response, and AR-V7 status was an independent predictor of PSA response in multivariable logistic regression analysis (p=0.03). High AR-V7 expression was associated with shorter PSA-PFS (median 2.4 vs 3.7 mo; p<0.001), shorter clinical PFS (median 2.7 vs 5.5 mo; p<0.001), and shorter OS (median 4.0 vs. 13.9 mo; p<0.001). On multivariable Cox regression analysis, high AR-V7 expression remained an independent predictor of shorter PSA-PFS (hazard ratio [HR] 7.0, 95% confidence interval [CI] 2.3-20.7; p<0.001), shorter clinical PFS (HR 2.3, 95% CI 1.1-4.9; p=0.02), and shorter OS (HR 3.0, 95% CI 1.4-6.3; p=0.005). Testing of AR-V7 mRNA levels in whole blood is a simple and promising approach to predict poor treatment outcome in mCRPC patients receiving abiraterone or enzalutamide. We established a method for determining AR-V7 status in whole blood. This test predicted treatment resistance in patients with metastatic castration-resistant

  3. Nuclear-specific AR-V7 Protein Localization is Necessary to Guide Treatment Selection in Metastatic Castration-resistant Prostate Cancer.

    PubMed

    Scher, Howard I; Graf, Ryon P; Schreiber, Nicole A; McLaughlin, Brigit; Lu, David; Louw, Jessica; Danila, Daniel C; Dugan, Lyndsey; Johnson, Ann; Heller, Glenn; Fleisher, Martin; Dittamore, Ryan

    2017-06-01

    Circulating tumor cells (CTCs) expressing AR-V7 protein localized to the nucleus (nuclear-specific) identify metastatic castration-resistant prostate cancer (mCRPC) patients with improved overall survival (OS) on taxane therapy relative to the androgen receptor signaling inhibitors (ARSi) abiraterone acetate, enzalutamide, and apalutamide. To evaluate if expanding the positivity criteria to include both nuclear and cytoplasmic AR-V7 localization ("nuclear-agnostic") identifies more patients who would benefit from a taxane over an ARSi. The study used a cross-sectional cohort. Between December 2012 and March 2015, 193 pretherapy blood samples, 191 of which were evaluable, were collected and processed from 161 unique mCRPC patients before starting a new line of systemic therapy for disease progression at the Memorial Sloan Kettering Cancer Center. The association between two AR-V7 scoring criteria, post-therapy prostate-specific antigen (PSA) change (PTPC) and OS following ARSi or taxane treatment, was explored. One criterion required nuclear-specific AR-V7 localization, and the other required an AR-V7 signal but was agnostic to protein localization in CTCs. Correlation of AR-V7 status to PTPC and OS was investigated. Relationships with survival were analyzed using multivariable Cox regression and log-rank analyses. A total of 34 (18%) samples were AR-V7-positive using nuclear-specific criteria, and 56 (29%) were AR-V7-positive using nuclear-agnostic criteria. Following ARSi treatment, none of the 16 nuclear-specific AR-V7-positive samples and six of the 32 (19%) nuclear-agnostic AR-V7-positive samples had ≥50% PTPC at 12 weeks. The strongest baseline factor influencing OS was the interaction between the presence of nuclear-specific AR-V7-positive CTCs and treatment with a taxane (hazard ratio 0.24, 95% confidence interval 0.078-0.79; p=0.019). This interaction was not significant when nuclear-agnostic criteria were used. To reliably inform treatment selection

  4. ACK1/TNK2 Regulates Histone H4 Tyr88-phosphorylation and AR Gene Expression in Castration-Resistant Prostate Cancer.

    PubMed

    Mahajan, Kiran; Malla, Pavani; Lawrence, Harshani R; Chen, Zhihua; Kumar-Sinha, Chandan; Malik, Rohit; Shukla, Sudhanshu; Kim, Jongphil; Coppola, Domenico; Lawrence, Nicholas J; Mahajan, Nupam P

    2017-06-12

    The androgen receptor (AR) is critical for the progression of prostate cancer to a castration-resistant (CRPC) state. AR antagonists are ineffective due to their inability to repress the expression of AR or its splice variant, AR-V7. Here, we report that the tyrosine kinase ACK1 (TNK2) phosphorylates histone H4 at tyrosine 88 upstream of the AR transcription start site. The WDR5/MLL2 complex reads the H4-Y88-phosphorylation marks and deposits the transcriptionally activating H3K4-trimethyl marks promoting AR transcription. Reversal of the pY88-H4 epigenetic marks by the ACK1 inhibitor (R)-9bMS-sensitized naive and enzalutamide-resistant prostate cancer cells and reduced AR and AR-V7 levels to mitigate CRPC tumor growth. Thus, a feedforward ACK1/pY88-H4/WDR5/MLL2/AR epigenetic circuit drives CRPC and is necessary for maintenance of the malignant state. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Evaluation of bone metastases by 18F-choline PET/CT in a patient with castration-resistant prostate cancer treated with radium-223.

    PubMed

    Scalzi, Piera; Baiocco, Cinzia; Genovese, Sabrina; Trevisan, Antonella; Sirotova, Zuzana; Poti, Carlo

    2017-02-03

    To date, bone metastases remain the main cause of morbidity and mortality in patients with metastatic castration-resistant prostate cancer (mCRPC). Therefore, the combination of accurate early detection of bony disease and effective treatment of these lesions is crucial in the management of mCRPC patients, but clinical trials specifically designed to test novel approaches are currently lacking. This report describes the case of a 74-year-old male with bone mCRPC and symptomatic and biochemical progression, who underwent radium-223 therapy, following previous treatment failure. 18F-choline positron emission tomography (PET)/computed tomography (CT) was used to assess changes in skeletal tumor activity before and after radium-223. Changes in prostate-specific antigen and alkaline phosphatase were also determined. 18F-choline PET/CT showed that treatment with radium-223 was able to effectively reduce bone metastatic disease, and this was accompanied by an excellent metabolic response. In clinical practice, metabolic assessment of lesions by 18F-choline PET/CT following radium-223 seems a valid approach to monitor treatment response. Until results from clinical trials become available, reporting of single cases relating to data on the use of this technique remains paramount.

  6. Inhibition of NF-kappa B signaling restores responsiveness of castrate resistant prostate cancer cells to anti-androgen treatment by decreasing androgen receptor variants expression

    PubMed Central

    Jin, Renjie; Yamashita, Hironobu; Yu, Xiuping; Wang, Jingbin; Franco, Omar E.; Wang, Yufen; Hayward, Simon W.; Matusik, Robert J.

    2014-01-01

    Androgen receptor splicing variants (ARVs) which lack the ligand-binding domain (LBD) are associated with the development of castration-resistant prostate cancer (CRPC), including resistance to the new generation of high affinity anti-androgens. However, the mechanism by which ARVs expression is regulated is not fully understood. In this study, we show that activation of classical NF-κB signaling increases the expression of ARVs in prostate cancer (PCa) cells and converts androgen sensitive PCa cells to become androgen insensitive; while, downregulation of NF-κB signaling inhibits ARVs expression and restores responsiveness of CRPC to anti-androgen therapy. In addition, we demonstrated that combination of anti-androgen with NF-κB targeted therapy inhibits efficiently tumor growth of human CRPC xenografts. These results indicate that induction ARVs by activated NF-κB signaling in PCa cells is a critical mechanism by which the PCa progresses to CRPC. This has important implications since it can prolong the survival of CRPC patients by restoring the tumors to once again respond to conventional androgen-deprivation therapy (ADT). PMID:25220414

  7. Custirsen in combination with docetaxel and prednisone for patients with metastatic castration-resistant prostate cancer (SYNERGY trial): a phase 3, multicentre, open-label, randomised trial.

    PubMed

    Chi, Kim N; Higano, Celestia S; Blumenstein, Brent; Ferrero, Jean-Marc; Reeves, James; Feyerabend, Susan; Gravis, Gwenaelle; Merseburger, Axel S; Stenzl, Arnulf; Bergman, Andries M; Mukherjee, Som D; Zalewski, Pawel; Saad, Fred; Jacobs, Cindy; Gleave, Martin; de Bono, Johann S

    2017-04-01

    Clusterin is a chaperone protein associated with treatment resistance and upregulated by apoptotic stressors such as chemotherapy. Custirsen is a second-generation antisense oligonucleotide that inhibits clusterin production. The aim of the SYNERGY trial was to investigate the effect of custirsen in combination with docetaxel and prednisone on overall survival in patients with metastatic castration-resistant prostate cancer. SYNERGY was a phase 3, multicentre, open-label, randomised trial set at 134 study centres in 12 countries. Patients were eligible for participation if they had: metastatic castration-resistant prostate cancer and had received no previous chemotherapy; prostate-specific antigen greater than 5 ng/mL; and a Karnofsky performance score of 70% or higher. Patients were randomly assigned 1:1 centrally to either the docetaxel, prednisone, and custirsen combination or docetaxel and prednisone alone. Patients were not masked to treatment allocation. Randomisation was stratified by opioid use for cancer-related pain and radiographic evidence of progression. All patients received docetaxel 75 mg/m(2) intravenously with 5 mg of prednisone orally twice daily. Patients assigned docetaxel, prednisone, and custirsen received weekly doses of custirsen 640 mg intravenously after three loading doses of 640 mg. The primary endpoint was overall survival analysed in the intention-to-treat population. Patients who received at least one study dose were included in the safety analysis set. This trial is registered with ClinicalTrials.gov, number NCT01188187. The trial is completed and final analyses are reported here. Between Dec 10, 2010, and Nov 7, 2012, 1022 patients were enrolled to the trial, of whom 510 were assigned docetaxel, prednisone, and custirsen and 512 were allocated docetaxel and prednisone. No difference in overall survival was recorded between the two groups (median survival 23·4 months [95% CI 20·9-24·8] with docetaxel, prednisone, and custirsen vs

  8. ROR-γ drives androgen receptor expression and represents a therapeutic target in castration-resistant prostate cancer.

    PubMed

    Wang, Junjian; Zou, June X; Xue, Xiaoqian; Cai, Demin; Zhang, Yan; Duan, Zhijian; Xiang, Qiuping; Yang, Joy C; Louie, Maggie C; Borowsky, Alexander D; Gao, Allen C; Evans, Christopher P; Lam, Kit S; Xu, Jianzhen; Kung, Hsing-Jien; Evans, Ronald M; Xu, Yong; Chen, Hong-Wu

    2016-05-01

    The androgen receptor (AR) is overexpressed and hyperactivated in human castration-resistant prostate cancer (CRPC). However, the determinants of AR overexpression in CRPC are poorly defined. Here we show that retinoic acid receptor-related orphan receptor γ (ROR-γ) is overexpressed and amplified in metastatic CRPC tumors, and that ROR-γ drives AR expression in the tumors. ROR-γ recruits nuclear receptor coactivator 1 and 3 (NCOA1 and NCOA3, also known as SRC-1 and SRC-3) to an AR-ROR response element (RORE) to stimulate AR gene transcription. ROR-γ antagonists suppress the expression of both AR and its variant AR-V7 in prostate cancer (PCa) cell lines and tumors. ROR-γ antagonists also markedly diminish genome-wide AR binding, H3K27ac abundance and expression of the AR target gene network. Finally, ROR-γ antagonists suppressed tumor growth in multiple AR-expressing, but not AR-negative, xenograft PCa models, and they effectively sensitized CRPC tumors to enzalutamide, without overt toxicity, in mice. Taken together, these results establish ROR-γ as a key player in CRPC by acting upstream of AR and as a potential therapeutic target for advanced PCa.

  9. Radium-223 dichloride: a review of its use in patients with castration-resistant prostate cancer with symptomatic bone metastases.

    PubMed

    Shirley, Matt; McCormack, Paul L

    2014-04-01

    Radium-223 dichloride (Xofigo®; formerly Alpharadin™) [hereafter referred to as radium-223] is a first-in-class alpha particle-emitting radiopharmaceutical that has recently been approved for the treatment of patients with castration-resistant prostate cancer (CRPC) with symptomatic bone metastases and no known visceral metastatic disease. Radium-223 is a calcium mimetic, which targets bone, delivering cytotoxic radiation to the sites of bone metastases. In the recently reported Alpharadin™ in Symptomatic Prostate Cancer (ALSYMPCA) phase III study, radium-223 was associated with significantly improved overall survival compared with placebo, making it the first bone-targeted CRPC therapy for which an overall survival benefit has been demonstrated. The ALSYMPCA study also demonstrated the beneficial effects of radium-223 on disease-related symptomatic skeletal events, pain and health-related quality of life. Radium-223 was generally well tolerated, being associated with low rates of myelosuppression and generally mild gastrointestinal adverse events. Thus, radium-223 is a valuable addition to the treatment options for this poor-prognosis population.

  10. Docetaxel-carboxymethylcellulose nanoparticles display enhanced anti-tumor activity in murine models of castration-resistant prostate cancer.

    PubMed

    Hoang, Bryan; Ernsting, Mark J; Murakami, Mami; Undzys, Elijus; Li, Shyh-Dar

    2014-08-25

    Docetaxel (DTX) remains the only effective drug for prolonging survival and improving quality of life of metastatic castration resistant prostate cancer (mCRPC) patients. Despite some clinical successes with DTX-based therapies, advent of cumulative toxicity and development of drug resistance limit its long-term clinical application. The integration of nanotechnology for drug delivery can be exploited to overcome the major intrinsic limitations of DTX therapy for mCRPC. We evaluated whether reformulation of DTX by facile conjugation to carboxymethylcellulose nanoparticles (Cellax) can improve the efficacy and safety of the drug in s.c. and bone metastatic models of CRPC. A single dose of the nanoparticles completely regressed s.c. PC3 tumor xenografts in mice. In addition, Cellax elicited fewer side effects compared to native DTX. Importantly, Cellax did not increase the expression of drug resistance molecules in androgen-independent PC3 prostate cancer cells in comparison with DTX. Lastly, in a bone metastatic model of CRPC, Cellax treatment afforded a 2- to 3-fold improvement in survival and enhancements in quality-of-life of the animals over DTX and saline controls. These results demonstrate the potential of Cellax in improving the treatment of mCRPC. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Inhibition of Androgen Receptor Nuclear Localization and Castration-Resistant Prostate Tumor Growth by Pyrroloimidazole-based Small Molecules.

    PubMed

    Masoodi, Khalid Z; Xu, Yadong; Dar, Javid A; Eisermann, Kurtis; Pascal, Laura E; Parrinello, Erica; Ai, Junkui; Johnston, Paul A; Nelson, Joel B; Wipf, Peter; Wang, Zhou

    2017-10-01

    The androgen receptor (AR) is a ligand-dependent transcription factor that controls the expression of androgen-responsive genes. A key step in androgen action, which is amplified in castration-resistant prostate cancer (CRPC), is AR nuclear translocation. Small molecules capable of inhibiting AR nuclear localization could be developed as novel therapeutics for CRPC. We developed a high-throughput screen and identified two structurally-related pyrroloimidazoles that could block AR nuclear localization in CRPC cells. We show that these two small molecules, 3-(4-ethoxyphenyl)-6,7-dihydro-5H-pyrrolo[1,2-a]imidazole (EPPI) and 3-(4-chlorophenyl)-6,7-dihydro-5H-pyrrolo[1,2-a]imidazole (CPPI) can inhibit the nuclear localization and transcriptional activity of AR and reduce the proliferation of AR-positive but not AR-negative prostate cancer cell lines. EPPI and CPPI did not inhibit nuclear localization of the glucocorticoid receptor or the estrogen receptor, suggesting they selectively target AR. In LNCaP tumor xenografts, CPPI inhibited the proliferation of relapsed LNCaP tumors. These findings suggest that EPPI and CPPI could serve as lead structures for the development of therapeutic agents for CRPC. Mol Cancer Ther; 16(10); 2120-9. ©2017 AACR. ©2017 American Association for Cancer Research.

  12. Global analysis of transcription in castration-resistant prostate cancer cells uncovers active enhancers and direct androgen receptor targets

    PubMed Central

    Toropainen, Sari; Niskanen, Einari A.; Malinen, Marjo; Sutinen, Päivi; Kaikkonen, Minna U.; Palvimo, Jorma J.

    2016-01-01

    Androgen receptor (AR) is a male sex steroid-activated transcription factor (TF) that plays a critical role in prostate cancers, including castration-resistant prostate cancers (CRPC) that typically express amplified levels of the AR. CRPC-derived VCaP cells display an excessive number of chromatin AR-binding sites (ARBs) most of which localize to distal inter- or intragenic regions. Here, we analyzed direct transcription programs of the AR in VCaP cells using global nuclear run-on sequencing (GRO-seq) and integrated the GRO-seq data with the ARB and VCaP cell-specific TF-binding data. Androgen immediately activated transcription of hundreds of protein-coding genes, including IGF-1 receptor and EGF receptor. Androgen also simultaneously repressed transcription of a large number of genes, including MYC. As functional enhancers have been postulated to produce enhancer-templated non-coding RNAs (eRNAs), we also analyzed the eRNAs, which revealed that only a fraction of the ARBs reside at functional enhancers. Activation of these enhancers was most pronounced at the sites that also bound PIAS1, ERG and HDAC3, whereas binding of HDAC3 and PIAS1 decreased at androgen-repressed enhancers. In summary, our genome-wide data of androgen-regulated enhancers and primary target genes provide new insights how the AR can directly regulate cellular growth and control signaling pathways in CPRC cells. PMID:27641228

  13. Combining p53 stabilizers with metformin induces synergistic apoptosis through regulation of energy metabolism in castration-resistant prostate cancer

    PubMed Central

    Chen, Long; Ahmad, Nihal; Liu, Xiaoqi

    2016-01-01

    ABSTRACT Since altered energy metabolism is a hallmark of cancer, many drugs targeting metabolic pathways are in active clinical trials. The tumor suppressor p53 is often inactivated in cancer, either through downregulation of protein or loss-of-function mutations. As such, stabilization of p53 is considered as one promising approach to treat those cancers carrying wild type (WT) p53. Herein, SIRT1 inhibitor Tenovin-1 and polo-like kinase 1 (Plk1) inhibitor BI2536 were used to stabilize p53. We found that both Tennovin-1 and BI2536 increased the anti-neoplastic activity of metformin, an inhibitor of oxidative phosphorylation, in a p53 dependent manner. Since p53 has also been shown to regulate metabolic pathways, we further analyzed glycolysis and oxidative phosphorylation upon drug treatments. We showed that both Tennovin-1 and BI2536 rescued metformin-induced glycolysis and that both Tennovin-1 and BI2536 potentiated metformin-associated inhibition of oxidative phosphorylation. Of significance, castration-resistant prostate cancer (CRPC) C4-2 cells show a much more robust response to the combination treatment than the parental androgen-dependent prostate cancer LNCaP cells, indicating that targeting energy metabolism with metformin plus p53 stabilizers might be a valid approach to treat CRPC carrying WT p53. PMID:26900800

  14. ROR-γ drives androgen receptor expression and represents a therapeutic target in castration-resistant prostate cancer

    PubMed Central

    Wang, Junjian; Zou, June X.; Xue, Xiaoqian; Cai, Demin; Zhang, Yan; Duan, Zhijian; Xiang, Qiuping; Yang, Joy C.; Louie, Maggie C.; Borowsky, Alexander D.; Gao, Allen C.; Evans, Christopher P.; Lam, Kit S.; Xu, Jianzhen; Kung, Hsing-Jien; Evans, Ronald M.; Xu, Yong; Chen, Hong-Wu

    2016-01-01

    The androgen receptor (AR) is overexpressed and hyperactivated in human castration-resistant prostate cancer (CRPC). However, the determinants of AR overexpression in CRPC are poorly defined. Here we show that retinoid acid receptor-related orphan receptor γ (ROR-γ) is overexpressed and amplified in metastatic CRPC tumors, and that ROR-γ drives AR expression in the tumors. ROR-γ recruits coactivators SRC-1 and -3 to an AR-RORE to stimulate AR gene transcription. ROR-γ antagonists suppress the expression of AR and its variant AR-V7 in prostate cancer (PCa) cell lines and tumors. ROR-γ antagonists also markedly diminish genome-wide AR binding, H3K27ac abundance and expression of the AR gene network. Lastly, ROR-γ antagonists suppressed tumor growth in multiple AR-expressing but not AR-negative xenograft PCa models, and effectively sensitized CRPC tumors to enzalutamide, without overt toxicity in mice. Together, these results establish ROR-γ as a key player in CRPC by acting upstream of AR and a potential therapeutic target for advanced PCa. PMID:27019329

  15. Genetic and Molecular Mechanisms in Assessing Response in Patients With Prostate Cancer Receiving Enzalutamide Therapy

    ClinicalTrials.gov

    2017-08-23

    Castration Levels of Testosterone; Castration-Resistant Prostate Carcinoma; Metastatic Prostate Carcinoma in the Soft Tissue; Metastatic Prostatic Adenocarcinoma; Prostate Carcinoma Metastatic in the Bone; PSA Progression; Recurrent Prostate Carcinoma; Stage III Prostate Adenocarcinoma; Stage IV Prostate Adenocarcinoma

  16. Predicting time to castration resistance in hormone sensitive prostate cancer by a personalization algorithm based on a mechanistic model integrating patient data.

    PubMed

    Elishmereni, Moran; Kheifetz, Yuri; Shukrun, Ilan; Bevan, Graham H; Nandy, Debashis; McKenzie, Kyle M; Kohli, Manish; Agur, Zvia

    2016-01-01

    Prostate cancer (PCa) is a leading cause of cancer death of men worldwide. In hormone-sensitive prostate cancer (HSPC), androgen deprivation therapy (ADT) is widely used, but an eventual failure on ADT heralds the passage to the castration-resistant prostate cancer (CRPC) stage. Because predicting time to failure on ADT would allow improved planning of personal treatment strategy, we aimed to develop a predictive personalization algorithm for ADT efficacy in HSPC patients. A mathematical mechanistic model for HSPC progression and treatment was developed based on the underlying disease dynamics (represented by prostate-specific antigen; PSA) as affected by ADT. Following fine-tuning by a dataset of ADT-treated HSPC patients, the model was embedded in an algorithm, which predicts the patient's time to biochemical failure (BF) based on clinical metrics obtained before or early in-treatment. The mechanistic model, including a tumor growth law with a dynamic power and an elaborate ADT-resistance mechanism, successfully retrieved individual time-courses of PSA (R(2) = 0.783). Using the personal Gleason score (GS) and PSA at diagnosis, as well as PSA dynamics from 6 months after ADT onset, and given the full ADT regimen, the personalization algorithm accurately predicted the individual time to BF of ADT in 90% of patients in the retrospective cohort (R(2) = 0.98). The algorithm we have developed, predicting biochemical failure based on routine clinical tests, could be especially useful for patients destined for short-lived ADT responses and quick progression to CRPC. Prospective studies must validate the utility of the algorithm for clinical decision-making. © 2015 Wiley Periodicals, Inc.

  17. The effect of 5-aminolevulinic acid and its derivatives on protoporphyrin IX accumulation and apoptotic cell death in castrate-resistant prostate cancer cells.

    PubMed

    Teper, Ervin; Makhov, Peter; Golovine, Konstantin; Canter, Daniel J; Myers, Cynthia B; Kutikov, Alexander; Sterious, Steven N; Uzzo, Robert G; Kolenko, Vladimir M

    2012-12-01

    To examine whether pharmacologically relevant zinc-binding agents are capable of depleting X-linked inhibitor of apoptosis protein in tumor cells. Our prior work reveals that treatment with zinc-chelating agents induces selective downregulation of the X-linked inhibitor of apoptosis protein in cancer cells of various origins. A precursor of the heme synthetic pathway, 5-aminolevulinic acid, is metabolized to protoporphyrin IX, which is highly reactive with zinc. We assessed whether modified versions of 5-aminolevulinic acid with lipophilic side chains can enhance efficacy and selectivity with respect to protoporphyrin IX accumulation, X-linked inhibitor of apoptosis protein depletion, and tumor necrosis factor-related apoptosis-inducing ligand-mediated apoptosis in human castration-resistant prostate cancer cells. Seven modified versions of 5-aminolevulinic acid (5 esters and 2 amides) were synthesized. Levels of endogenous protoporphyrin IX were examined by flow cytometry. X-linked inhibitor of apoptosis protein expression was examined by Western blotting. terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling assay was used to assess cell apoptosis. Results were compared qualitatively. Accumulation of endogenous protoporphyrin IX by castration-resistant prostate cancer cells was shown to be directly related to the carbon chain length of the esterified 5-aminolevulinic acid derivatives. In fact, treatment with 5-aminolevulinic acid-HE was superior to that achieved by 5-aminolevulinic acid with respect to X-linked inhibitor of apoptosis protein downregulation. 5-aminolevulinic acid and 5-aminolevulinic acid-HE in combination with tumor necrosis factor-related apoptosis-inducing ligand significantly enhanced apoptotic cell death in castration-resistant prostate cancer cell lines. Esterified derivatives of 5-aminolevulinic acid alone or in combination with other agents may provide therapeutic opportunities in the treatment of castration-resistant

  18. Noninvasive Detection of AR-FL/AR V7 as a Predictive Biomarker for Therapeutic Resistance in Men with Metastatic Castration-Resistant Prostate Cancer

    DTIC Science & Technology

    2016-10-01

    Using a laboratory- developed, RNA -based assay modified from a commercially available circulating tumor cell (CTC) detection platform, we have developed...for therapeutic resistance in men with metastatic castration-resistant prostate cancer. Using a laboratory-developed, RNA -based assay modified from...between CTC AR expression with contemporaneously acquired fresh CRPC biopsy expression, and with expression detected in cell-free exosome RNA . Subtask 1

  19. (11)C-Choline PET/CT in castration-resistant prostate cancer patients treated with docetaxel.

    PubMed

    Ceci, Francesco; Castellucci, Paolo; Graziani, Tiziano; Schiavina, Riccardo; Renzi, Riccardo; Borghesi, Marco; Di Tullio, Piergiorgio; Brunocilla, Eugenio; Ardizzoni, Andrea; Fanti, Stefano

    2016-01-01

    To investigate the role of (11)C-choline PET/CT for evaluating the response to treatment in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with docetaxel in comparison with PSA response. Inclusion criteria were (a) proven mCRPC, (b) docetaxel as first line of chemotherapy (docetaxel 75 mg/m(2) + prednisone 5 mg), and (c) (11)C-choline PET/CT and PSA values assessed before and after docetaxel administration. A total of 61 patients were retrospectively enrolled (mean age 68.9 years, range 57 - 84 years). (11)C-Choline PET/CT was performed at baseline before docetaxel treatment (PET1) and after the end of treatment (PET2). PSA values were measured before treatment (PSA1) and after treatment (PSA2). PET2 was reported as complete response (CR), partial response (PR) or stable disease (SD). Progressive disease (PD) was considered if a new lesion was seen. PSA trend was calculated from the change in absolute values between PSA1 and PSA2. A decrease of ≥50 % between PSA1 and PSA2 was considered a PSA response. Clinical, radiological and laboratory follow-up ranged from 6 to 53 months (mean 13.5 months). Of the 61 patients, 40 (65.5 %) showed PD on PET2, 13 (21.3 %) showed SD, 2 (3.4 %) showed PR, and 6 (9.8 %) showed CR. An increasing PSA trend was seen in 29 patients (47.5 %) and a decreasing PSA trend in 32 patients (52.5 %). A PSA response of ≥50 % was seen in 25 patients (41 %). Radiological PD was seen in 23 of the 29 patients (79.3 %) with an increasing PSA trend, in 16 of the 32 patients (50 %) with a decreasing PSA trend, and in 11 of the 25 patients (44 %) with a PSA response of ≥50 %. In the multivariate statistical analysis, the presence of more than ten bone lesions detected on PET1 was significantly associated with an increased probability of PD on PET2. No association was observed between PSA level and PD on PET2. Our results suggest that an increasing PSA trend measured after docetaxel treatment could

  20. Radiopharmaceuticals for Palliation of Bone Pain in Patients with Castration-resistant Prostate Cancer Metastatic to Bone: A Systematic Review.

    PubMed

    Jong, Joyce M van Dodewaard-de; Oprea-Lager, Daniela E; Hooft, Lotty; de Klerk, John M H; Bloemendal, Haiko J; Verheul, Henk M W; Hoekstra, Otto S; van den Eertwegh, Alfons J M

    2016-09-01

    The majority of patients with castration-resistant prostate cancer develop bone metastatic disease. It is often challenging to optimally palliate malignant bone pain. In case of multifocal pain due to diffuse osteoblastic metastases, treatment with bone-seeking radiopharmaceuticals can be considered. This systematic review evaluates the efficacy of different bone-seeking radiopharmaceuticals for palliation of malignant bone pain from prostate cancer. The PubMed (Medline) and Embase databases were searched for publications on 89-strontium-chloride ((89)Sr), 153-samarium-EDTMP ((153)Sm), 186-rhenium-HEDP ((186)Re), 188-rhenium-HEDP ((188)Re), and 223-radium-chloride ((223)Ra). Randomised controlled trials and prospective cohort studies were included. Metastatic bone pain had to be registered as outcome measure for prostate cancer patients separately. This review included 36 articles of which 13 randomised trials and 23 prospective studies. Of all trials, 10 studies used (89)Sr, 7 (153)Sm, 12 (186)Re, 2 (188)Re, and 2 (223)Ra; three reported on a combination of different radionuclides. Only a few trials contained a blinding procedure and several studies contained incomplete follow-up or lack of intention-to-treat analysis. It was not possible to calculate a pooled estimate of pain response to treatment with any of the radionuclides because different definitions of pain response were used. Overall, pain response percentages greater than 50-60% were seen with each radionuclide. Haematological toxicity was reported in 26 of the 36 studies and more than half of these trials stated no grade 3/4 leukopenia or thrombocytopenia occurred. In this report we reviewed the efficacy of bone-seeking radionuclides for treating bone pain from metastatic prostate cancer. Overall, treatment with bone-seeking radionuclides resulted in pain responses greater than 50-60%. Copyright © 2015 European Association of Urology. Published by Elsevier B.V. All rights reserved.

  1. Impact of enzalutamide on patient-related outcomes in metastatic castration-resistant prostate cancer: current perspectives

    PubMed Central

    Luo, Jia; Graff, Julie N

    2016-01-01

    Prostate cancer claims the lives of more than 25,000 men in the United States yearly, most from metastatic disease. In the past decade, several new medications have been approved for the treatment of metastatic prostate cancer including the antiandrogen enzalutamide. In addition, there has been mounting interest in evaluating health-related quality of life (QoL) in patients with cancer including new more detailed recommendations released by the Prostate Cancer Working Group 3 on how to evaluate patient-related outcomes in clinical trials. A total of four randomized double-blind placebo-controlled trials have evaluated patients with metastatic castration-resistant prostate cancer (mCRPC) randomized to receive enzalutamide vs control or bicalutamide. Each study used validated health-related QoL and pain surveys to evaluate patient-related outcomes. The studies suggest that patients with mCRPC, including those aged 75 years and older, have favorable overall QoL scores taking enzalutamide compared to standard of care. There was short-term improved pain control in patients taking enzalutamide compared to those in the placebo group. Some commonly reported adverse effects included fatigue, back pain, and hot flashes. These studies were limited in their patient attrition in filling out surveys as well as difficulty in comparing them to each other. Future studies examining patients with mCRPC taking enzalutamide will have to rigorously standardize ways patient-reported outcomes are collected and evaluate patients in a more diversified real-world population. PMID:27942507

  2. Quercetin-loaded nanomicelles to circumvent human castration-resistant prostate cancer in vitro and in vivo.

    PubMed

    Zhao, Jing; Liu, Juan; Wei, Tuo; Ma, Xiaowei; Cheng, Qiang; Huo, Shuaidong; Zhang, Chunqiu; Zhang, Yanan; Duan, Xianglin; Liang, Xing-Jie

    2016-03-07

    Prostate cancer is highly prevalent and has become the second leading cause of cancer-related death in men. Its treatment remains a challenge in the clinic, particularly in patients who have advanced to "castration-resistant prostate cancer" (CRPC). Thus, more effective therapeutic strategies are required. Quercetin (QCT) is a natural flavonoid compound that has attracted increasing interest due to its anticancer activity. However, the clinical application of quercetin is largely hampered by its poor water solubility and low bioavailability. The objective of this study was to evaluate the therapeutic potential of novel QCT-loaded nanomicelles (M-QCTs) assembled from DSPE-PEG2000 for prostate cancer treatment. Our results indicated that QCT was efficiently encapsulated into micelles up to 1 mg mL(-1), which corresponds to a 450-fold increase of its water solubility. In vitro studies showed that the half-maximal inhibitory concentration (IC50) value (20.2 μM) of M-QCTs was much lower than free QCT (>200 μM). Thus, M-QCTs were considerably more effective than free QCT in proliferation inhibition and apoptosis induction of human androgen-independent PC-3 cells. Furthermore, M-QCTs showed superior antitumor efficacy and the tumor proliferation rate reduced by 52.03% compared to the control group in the PC-3 xenograft mouse model, possibly due to increased accumulation of M-QCTs at the tumor site by the enhanced permeability and retention (EPR) effect. Collectively, our studies demonstrated that M-QCTs significantly increase drug accumulation at the tumor site and exhibit superior anticancer activity in prostate cancer. Thus, our nanomicelle-based drug delivery system constitutes a promising and effective therapeutic strategy for clinical treatment.

  3. SU-D-303-01: Spatial Distribution of Bone Metastases In Metastatic Castrate-Resistant Prostate Cancer

    SciTech Connect

    Perk, T; Bradshaw, T; Harmon, S; Perlman, S; Liu, G; Jeraj, R

    2015-06-15

    Purpose: Identification of metastatic bone lesions is critical in prostate cancer, where treatments may be more effective in patients with fewer lesions. This study aims characterize the distribution and spread of bone lesions and create a probability map of metastatic spread in bone. Methods: Fifty-five metastatic castrate-resistant prostate cancer patients received up to 3 whole-body [F-18]NaF PET/CT scans. Lesions were identified by physician on PET/CT and contoured using a threshold of SUV>15. An atlas-based segmentation method was used to create CT regions, which determined skeletal location of lesions. Patients were divided into 3 groups with low (N<40), medium (40100) numbers of lesions. A combination of articulated and deformable registrations was used to register the skeletal segments and lesions of each patient to a single skeleton. All the lesion data was then combined to make a probability map. Results: A total of 4038 metastatic lesions (mean 74, range 2–304) were identified. Skeletal regions with highest occurrence of lesions included ribs, thoracic spine, and pelvis with 21%, 19%, and 15% of the total number lesions and 8%, 18%, and 31 % of the total lesion volume, respectively. Interestingly, patients with fewer lesions were found to have a lower proportion of lesions in the ribs (9% in low vs. 27% in high number of lesions). Additionally, the probability map showed specific areas in the spine and pelvis where over 75% of patients had metastases, and other areas in the skeleton with a less than 2% of metastases. Conclusion: We identified skeletal regions with higher incidence of metastases and specific sub-regions in the skeleton that had high or low probability of occurrence of metastases. Additionally, we found that metastatic lesions in the ribs and skull occur more commonly in advanced disease. These results may have future applications in computer-aided diagnosis. Funding from the Prostate Cancer Foundation.

  4. ELEVATION OF C-FLIP IN CASTRATE-RESISTANT PROSTATE CANCER ANTAGONIZES THERAPEUTIC RESPONSE TO ANDROGEN-RECEPTOR TARGETED THERAPY

    PubMed Central

    McCourt, Clare; Maxwell, Pamela; Mazzucchelli, Roberta; Montironi, Rodolfo; Scarpelli, Marina; Salto-Tellez, Manuel; O’Sullivan, Joe M.; Longley, Daniel B.; Waugh, David J.J.

    2012-01-01

    Purpose To characterize the importance of cellular Fas-associated death domain (FADD)-like interleukin 1β-converting enzyme (FLICE) inhibitory protein (c-FLIP), a key regulator of caspase 8 (FLICE)-promoted apoptosis, in modulating the response of prostate cancer (CaP) cells to androgen receptor (AR)-targeted therapy. Experimental Design c-FLIP expression was characterized by immunohistochemical analysis of prostatectomy tissue. The functional importance of c-FLIP to survival and modulating response to bicalutamide was studied by molecular and pharmacological interventions. Results c-FLIP expression was increased in high-grade prostatic intra-epithelial neoplasia (HGPIN) and CaP tissue relative to normal prostate epithelium (P<0.001). Maximal c-FLIP expression was detected in castrate-resistant CaP (CRPC) (P<0.001). In vitro, silencing of c-FLIP induced spontaneous apoptosis and increased 22Rv1 and LNCaP cell sensitivity to bicalutamide, determined by flow cytometry, PARP cleavage and caspase activity assays. The histone deacetylase inhibitors (HDACi), droxinostat and SAHA, also down-regulated c-FLIP expression, induced caspase-8 and caspase-3/7 mediated apoptosis and increased apoptosis in bicalutamide-treated cells. Conversely, the elevated expression of c-FLIP detected in the CRPC cell line VCaP underpinned their insensitivity to bicalutamide and SAHA in vitro. However, knockdown of c-FLIP induced spontaneous apoptosis in VCaP cells, indicating its relevance to cell survival and therapeutic resistance. Conclusion c-FLIP reduces the efficacy of AR-targeted therapy and maintains the viability of CaP cells. A combination of HDACi with androgen-deprivation therapy (ADT) may be effective in early-stage disease, using c-FLIP expression as a predictive biomarker of sensitivity. Direct targeting of c-FLIP however may be relevant to enhance the response of existing and novel therapeutics in CRPC. PMID:22623731

  5. Phase Ib Study of Enzalutamide in Combination with Docetaxel in Men with Metastatic Castration-Resistant Prostate Cancer

    PubMed Central

    Morris, Michael J.; Rathkopf, Dana E.; Novotny, William; Gibbons, Jacqueline A.; Peterson, Amy C.; Khondker, Zakaria; Ouatas, Taoufik; Scher, Howard I.; Fleming, Mark T.

    2017-01-01

    Purpose Preclinical evidence suggests that both docetaxel and enzalutamide target androgen receptor translocation and signaling. This phase Ib study assessed the safety, tolerability, and pharmacokinetics of docetaxel when administered with enzalutamide as first-line systemic chemotherapy in men with metastatic castration-resistant prostate cancer (mCRPC). Experimental Methods Docetaxel-naïve patients received 21-day cycles of docetaxel (75 mg/m2). Enzalutamide (160 mg/day) was administered daily starting on day 2 of cycle 1. Patients were allowed to stop and restart docetaxel at any time following cycle 2. Treatment continued indefinitely until unacceptable toxicity or discontinuation due to investigator or patient preference. Results A total of 22 patients received docetaxel, of whom 21 also received enzalutamide. Docetaxel was administered for a median of 5.0 cycles and enzalutamide for a median of 12.0 months. With concomitant treatment, geometric mean docetaxel exposure decreased by 11.8%, whereas peak concentrations decreased by 3.7% relative to docetaxel alone. The most common toxicities observed during the period of concomitant therapy were neutropenia (86.4%) and fatigue (77.3%). Common toxicities observed with post-docetaxel enzalutamide were constipation (23.8%), decreased appetite (19.0%), fatigue (19.0%), and musculoskeletal pain (19.0%). Treatment with enzalutamide and docetaxel resulted in prostate-specific antigen decreases in almost all patients based on exploratory analysis of available baseline and on-study prostate-specific antigen data. Conclusions The combination of docetaxel and enzalutamide is feasible, although higher rates of neutropenia and neutropenic fever than anticipated were observed. Reductions in docetaxel exposure with enzalutamide coadministration were not considered clinically meaningful. This combination warrants further study in a larger mCRPC population. PMID:26858312

  6. Treatment sequence in castration-resistant prostate cancer: A retrospective study in the new anti-androgen era.

    PubMed

    Hoshi, Senji; Numahata, Kenji; Ono, Kunio; Yasuno, Nobuhiro; Bilim, Vladimir; Hoshi, Kiyotsugu; Amemiya, Hiroshi; Sasagawa, Isoji; Ohta, Shoichiro

    2017-10-01

    In recent years, abiraterone acetate (AA) and enzalutamide (EZL) have become available for the treatment of cancer. Prior clinical trials have demonstrated the benefits of these agents in males with castration-resistant prostate cancer (CRPC). The optimal sequencing of available therapies in the context of efficacy and known cross-resistance remains uncertain. Based on the mechanisms of action and accessible clinical data, AA and EZL may be indicated for the early stages of prostate cancer. Until clinical trials are conducted to determine the best treatment sequence, individualized therapy is required for each patient based on the clinicopathological characteristics. In the present study, 46 sequential patients (median age: 77, range 59-89; median serum PSA level: 56 ng/ml, range 1.5-3,211) with CRPC treated with EZL (160 mg/day) were retrospectively analyzed between June 2014 and July 2015 at the following institutions: Yamagata Prefectural Central Hospital (Yamagata, Japan); Yamagata Tokushukai Hospital (Yamagata, Japan); Ishinomaki Red Cross Hospital (Ishinomaki, Japan); Kan-etsu Hospital (Tsurugashima, Japan); Niigata Cancer Center Hospital (Niigata, Japan); Sakado Central Hospital (Sakado, Japan). A total of 18 patients were pre-treated with Docetaxel (DOC) and 28 patients were DOC-naïve. Once EZL therapy was initiated, increases in prostate specific antigen (PSA) levels were observed in 3/18 patients (17%) pre-treated with DOC and in 6/20 (30%) who were DOC-naïve. In total, 8/28 DOC-naïve patients were treated with AA without EZL. An increase in the PSA level was observed in only 1/8 (12%) cases following AA treatment in the DOC-naïve group. It was demonstrated that AA had a better efficacy in DOC-naïve patients. The efficacy of EZL was limited in AA-pre-treated patients following DOC administration.

  7. Treatment sequence in castration-resistant prostate cancer: A retrospective study in the new anti-androgen era

    PubMed Central

    Hoshi, Senji; Numahata, Kenji; Ono, Kunio; Yasuno, Nobuhiro; Bilim, Vladimir; Hoshi, Kiyotsugu; Amemiya, Hiroshi; Sasagawa, Isoji; Ohta, Shoichiro

    2017-01-01

    In recent years, abiraterone acetate (AA) and enzalutamide (EZL) have become available for the treatment of cancer. Prior clinical trials have demonstrated the benefits of these agents in males with castration-resistant prostate cancer (CRPC). The optimal sequencing of available therapies in the context of efficacy and known cross-resistance remains uncertain. Based on the mechanisms of action and accessible clinical data, AA and EZL may be indicated for the early stages of prostate cancer. Until clinical trials are conducted to determine the best treatment sequence, individualized therapy is required for each patient based on the clinicopathological characteristics. In the present study, 46 sequential patients (median age: 77, range 59–89; median serum PSA level: 56 ng/ml, range 1.5–3,211) with CRPC treated with EZL (160 mg/day) were retrospectively analyzed between June 2014 and July 2015 at the following institutions: Yamagata Prefectural Central Hospital (Yamagata, Japan); Yamagata Tokushukai Hospital (Yamagata, Japan); Ishinomaki Red Cross Hospital (Ishinomaki, Japan); Kan-etsu Hospital (Tsurugashima, Japan); Niigata Cancer Center Hospital (Niigata, Japan); Sakado Central Hospital (Sakado, Japan). A total of 18 patients were pre-treated with Docetaxel (DOC) and 28 patients were DOC-naïve. Once EZL therapy was initiated, increases in prostate specific antigen (PSA) levels were observed in 3/18 patients (17%) pre-treated with DOC and in 6/20 (30%) who were DOC-naïve. In total, 8/28 DOC-naïve patients were treated with AA without EZL. An increase in the PSA level was observed in only 1/8 (12%) cases following AA treatment in the DOC-naïve group. It was demonstrated that AA had a better efficacy in DOC-naïve patients. The efficacy of EZL was limited in AA-pre-treated patients following DOC administration. PMID:28855993

  8. Phase II Multicenter Study of Abiraterone Acetate Plus Prednisone Therapy in Patients With Docetaxel-Treated Castration-Resistant Prostate Cancer

    PubMed Central

    Danila, Daniel C.; Morris, Michael J.; de Bono, Johann S.; Ryan, Charles J.; Denmeade, Samuel R.; Smith, Matthew R.; Taplin, Mary-Ellen; Bubley, Glenn J.; Kheoh, Thian; Haqq, Christopher; Molina, Arturo; Anand, Aseem; Koscuiszka, Michael; Larson, Steve M.; Schwartz, Lawrence H.; Fleisher, Martin; Scher, Howard I.

    2010-01-01

    Purpose Persistence of ligand-mediated androgen receptor signaling has been documented in castration-resistant prostate cancers (CRPCs). Abiraterone acetate (AA) is a potent and selective inhibitor of CYP17, which is required for androgen biosynthesis in the testes, adrenal glands, and prostate tissue. This trial evaluated the efficacy and safety of AA in combination with prednisone to reduce the symptoms of secondary hyperaldosteronism that can occur with AA monotherapy. Patients and Methods Fifty-eight men with progressive metastatic CRPC who experienced treatment failure with docetaxel-based chemotherapy received AA (1,000 mg daily) with prednisone (5 mg twice daily). Twenty-seven (47%) patients had received prior ketoconazole. The primary outcome was ≥ 50% prostate-specific antigen (PSA) decline, with objective response by Response Evaluation Criteria in Solid Tumors (RECIST) criteria, and changes in Eastern Cooperative Oncology Group (ECOG) performance status (PS) and circulating tumor cell (CTC) numbers. Safety was also evaluated. Results A ≥ 50% decline in PSA was confirmed in 22 (36%) patients, including 14 (45%) of 31 ketoconazole-naïve and seven (26%) of 27 ketoconazole-pretreated patients. Partial responses were seen in four (18%) of 22 patients with RECIST-evaluable target lesions. Improved ECOG PS was seen in 28% of patients. Median time to PSA progression was 169 days (95% CI, 82 to 200 days). CTC conversions with treatment from ≥ 5 to < 5 were noted in 10 (34%) of 29 patients. The majority of AA-related adverse events were grade 1 to 2, and no AA-related grade 4 events were seen. Conclusion AA plus prednisone was well tolerated, with encouraging antitumor activity in heavily pretreated CRPC patients. The incidence of mineralocorticoid-related toxicities (hypertension or hypokalemia) was reduced by adding low-dose prednisone. The combination of AA plus prednisone is recommended for phase III investigations. PMID:20159814

  9. A urologic oncology roundtable discussion: issues to consider in choosing treatment for metastatic castration-resistant prostate cancer.

    PubMed

    Taplin, Mary-Ellen; Berry, William R; Casey, Alison M; Aslo, Angel

    2013-01-01

    A recent Elsevier survey of 100 urologists and 100 medical oncologists who treat patients with castration-resistant prostate cancer (CRPC) identified a knowledge gap in their understanding of the recently approved therapies and what information they wanted to know concerning how and when to properly prescribe these treatments. The survey also revealed that approximately 30% of urologists had yet to prescribe one of the newly approved therapies. In response to these findings, a panel of topic experts in the fields of oncology, nursing, and specialty pharmacy convened for a roundtable discussion and to develop a companion summary article to provide a knowledge-based perspective for physicians treating patients with metastatic CRPC (http://prostatecancer.urologiconcology.org/). These participating oncology experts discussed how CRPC is defined, how the newly approved agents should be sequenced in the management of a typical patient with CRPC, and the clinical considerations regarding the role of specialty pharmacy providers and nurse practitioners as patient advocates when selecting these therapies for treating metastatic CRPC.

  10. Radium-223 Therapy for Patients with Metastatic Castrate-Resistant Prostate Cancer: An Update on Literature with Case Presentation

    PubMed Central

    Appleman, Leonard J.; Mountz, James M.

    2016-01-01

    Background and Purpose. Radium-223 dichloride (Xofigo®, Bayer HealthCare Pharmaceuticals Inc.) is the first α-particle emitter therapeutic agent approved by the FDA, with benefits in overall survival and delay in symptomatic skeletal event for patients with metastatic castrate-resistant prostate cancer (CRPC). Recent post hoc analyses of the phase III ALSYMPCA trial support the previously established safety profile as well as therapeutic effect and clinical outcome of Radium-223. Currently, Radium-223 is approved as a single agent therapy for metastatic CRPC. Clinical trials are currently investigating Radium-223 in additional clinical settings such as earlier asymptomatic disease and in combination with other agents including hormonal therapeutic agents and immunotherapeutic as well as chemotherapeutic agents. Trials are also ongoing in patients with other primary cancers such as breast cancer, thyroid cancer, and renal cancer metastatic to bone. In this article, the physics and radiobiology, as well as a literature update on the use of Radium-223, are provided along with case presentations, aiming at a better appreciation of research data as well as the assimilation of research data into clinical practice. PMID:27774318

  11. Radium-223 Therapy for Patients with Metastatic Castrate-Resistant Prostate Cancer: An Update on Literature with Case Presentation.

    PubMed

    Nguyen, Nghi C; Shah, Muhammad; Appleman, Leonard J; Parikh, Rahul; Mountz, James M

    2016-01-01

    Background and Purpose. Radium-223 dichloride (Xofigo®, Bayer HealthCare Pharmaceuticals Inc.) is the first α-particle emitter therapeutic agent approved by the FDA, with benefits in overall survival and delay in symptomatic skeletal event for patients with metastatic castrate-resistant prostate cancer (CRPC). Recent post hoc analyses of the phase III ALSYMPCA trial support the previously established safety profile as well as therapeutic effect and clinical outcome of Radium-223. Currently, Radium-223 is approved as a single agent therapy for metastatic CRPC. Clinical trials are currently investigating Radium-223 in additional clinical settings such as earlier asymptomatic disease and in combination with other agents including hormonal therapeutic agents and immunotherapeutic as well as chemotherapeutic agents. Trials are also ongoing in patients with other primary cancers such as breast cancer, thyroid cancer, and renal cancer metastatic to bone. In this article, the physics and radiobiology, as well as a literature update on the use of Radium-223, are provided along with case presentations, aiming at a better appreciation of research data as well as the assimilation of research data into clinical practice.

  12. Identification of novel SNPs associated with risk and prognosis in patients with castration-resistant prostate cancer.

    PubMed

    Sissung, Tristan M; Deeken, John; Leibrand, Crystal R; Price, Douglas K; Ehrlich, Sheryl; Steinberg, Seth M; Liewehr, David J; Dahut, William; Figg, William D

    2016-12-01

    Metabolism and transport play major roles in life-long exposure to endogenous and exogenous carcinogens. We therefore explored associations between polymorphisms in absorption, distribution, metabolism and elimination genes and the risk and prognosis of castration-resistant prostate cancer (CRPC). A total of 634 genotypes were tested in 74 patients using the Affymetrix DMETv1.0 platform. No relation to risk was found. Three SNPs were associated with CRPC prognosis in Caucasians: ABCB11 rs7602171G>A (p = 0.003; n = 30; hazard ratio [HR]: 0.307), GSTP1 rs1799811C>T (p = 0.001; n = 38; HR: 0.254) and SLC5A6 rs1395 (p = 0.004; n = 35; HR: 3.15). Two other polymorphisms among Caucasians were associated with interesting trends: ABCB4 rs2302387C>T (p = 0.039) and ABCC5 rs939339A>G (p = 0.018). This exploratory study is the first to show that polymorphisms in several absorption, distribution, metabolism and elimination genes may be associated with CRPC prognosis.

  13. Radium-223 dichloride: illustrating the benefits of a multidisciplinary approach for patients with metastatic castration-resistant prostate cancer

    PubMed Central

    Renzulli, Joseph F; Collins, Jennifer; Mega, Anthony

    2015-01-01

    Improving options for patients with metastatic castration-resistant prostate cancer (mCRPC) provide latitude in designing treatment plans that meet patients’ medical needs and personal goals. The field’s rapid evolution opens avenues for contributions by multiple medical specialties and requires considering more options to ensure that each patient receives the most appropriate care. A multidisciplinary clinic (MDC) focusing on patients with cancers of the genitourinary tract demonstrates an efficient and cost-effective means of integrating the diverse professional knowledge and skills needed to develop an optimal patient treatment plan. As a guide to establishing an MDC for patients with mCRPC, this article describes the operation of the Genitourinary MDC at The Miriam Hospital in Providence, RI – specifically, the successful incorporation of radium-223 dichloride (radium-223) into the treatment algorithm for men with mCRPC and symptomatic bone metastases. Radium-223 is a new treatment that, unlike earlier radionuclide therapies, has shown a survival advantage in a large randomized phase 3 trial (ALSYMPCA). The overall survival benefit was comparable to that of newer immuno-and hormonal therapies in similar populations. Radium-223 treatment also delayed onset of symptomatic skeletal events. Both benefits were independent of prior docetaxel therapy or concurrent bisphosphonate use. In our clinic, radium-223 is used primarily to extend patient survival. Patient selection, patient management, and treatment sequencing are discussed here in the context of a multidisciplinary environment. PMID:26089679

  14. External validation of a prognostic model predicting overall survival in metastatic castrate-resistant prostate cancer patients treated with abiraterone.

    PubMed

    Ravi, Praful; Mateo, Joaquin; Lorente, David; Zafeiriou, Zafeiris; Altavilla, Amelia; Ferraldeschi, Roberta; Sideris, Spyridon; Grist, Emily; Smith, Alan; Wong, Sophia; Bianchini, Diletta; Attard, Gerhardt; de Bono, Johann S

    2014-07-01

    A prognostic model was derived from the population of the COU-AA-301 phase 3 trial for metastatic castrate-resistant prostate cancer patients treated with abiraterone after docetaxel, and it stratifies patients into three risk groups based on clinical parameters. We validated this model in an independent cohort of patients treated with abiraterone after docetaxel outside a clinical trial (group A; n=94) and explored its utility in patients treated with abiraterone in the prechemotherapy setting (group B; n=64). For group A, median overall survival (mOS) was significantly different across the three prognostic groups (good: n=39, mOS: 21.8 mo; intermediate: n=44, mOS: 10.6 mo; poor: n=7, mOS: 6.8 mo; p<0.001; area under the curve [AUC]: 0.71). Analysis of group B confirmed the ability of the model to prognosticate for survival in the prechemotherapy setting: (good: n=44, mOS: 45.6 mo; intermediate or poor: n=20, mOS: 34.5 mo; p=0.042; AUC: 0.61). These results serve to validate the prognostic model in an independent population treated with abiraterone after docetaxel and support clinical implementation of the score. Calibration of the model was poorer in patients receiving abiraterone prechemotherapy. Prospective evaluation of this model in clinical trials is needed.

  15. Bioactive natural products for chemoprevention and treatment of castration-resistant prostate cancer.

    PubMed

    Kallifatidis, Georgios; Hoy, James J; Lokeshwar, Bal L

    2016-10-01

    Prostate cancer (PCa), a hormonally-driven cancer, ranks first in incidence and second in cancer related mortality in men in most Western industrialized countries. Androgen and androgen receptor (AR) are the dominant modulators of PCa growth. Over the last two decades multiple advancements in screening, treatment, surveillance and palliative care of PCa have significantly increased quality of life and survival following diagnosis. However, over 20% of patients initially diagnosed with PCa still develop an aggressive and treatment-refractory disease. Prevention or treatment for hormone-refractory PCa using bioactive compounds from marine sponges, mushrooms, and edible plants either as single agents or as adjuvants to existing therapy, has not been clinically successful. Major advancements have been made in the identification, testing and modification of the existing molecular structures of natural products. Additionally, conjugation of these compounds to novel matrices has enhanced their bio-availability; a big step towards bringing natural products to clinical trials. Natural products derived from edible plants (nutraceuticals), and common folk-medicines might offer advantages over synthetic compounds due to their broader range of targets, as compared to mostly single target synthetic anticancer compounds; e.g. kinase inhibitors. The use of synthetic inhibitors or antibodies that target a single aberrant molecule in cancer cells might be in part responsible for emergence of treatment refractory cancers. Nutraceuticals that target AR signaling (epigallocatechin gallate [EGCG], curcumin, and 5α-reductase inhibitors), AR synthesis (ericifolin, capsaicin and others) or AR degradation (betulinic acid, di-indolyl diamine, sulphoraphane, silibinin and others) are prime candidates for use as adjuvant or mono-therapies. Nutraceuticals target multiple pathophysiological mechanisms involved during cancer development and progression and thus have potential to simultaneously

  16. Investigating Genomic Mechanisms of Treatment Resistance in Castration Resistant Prostate Cancer

    DTIC Science & Technology

    2014-05-01

    this study is to evaluate the antitumor efficacy of ARN-509 as monotherapy or in combination with testosterone suppression in men with non-metastatic...castration-sensitive prostate cancer after definitive prostate therapy. Role: Site PI PHS 398/2590 (Rev. 06/09) Continuation Format Page 4

  17. PTEN loss in circulating tumour cells correlates with PTEN loss in fresh tumour tissue from castration-resistant prostate cancer patients

    PubMed Central

    Punnoose, Elizabeth A; Ferraldeschi, Roberta; Szafer-Glusman, Edith; Tucker, Eric K; Mohan, Sankar; Flohr, Penelope; Riisnaes, Ruth; Miranda, Susana; Figueiredo, Ines; Rodrigues, Daniel Nava; Omlin, Aurelius; Pezaro, Carmel; Zhu, Jin; Amler, Lukas; Patel, Premal; Yan, Yibing; Bales, Natalee; Werner, Shannon L; Louw, Jessica; Pandita, Ajay; Marrinucci, Dena; Attard, Gerhardt; de Bono, Johann

    2015-01-01

    Background: PTEN gene loss occurs frequently in castration-resistant prostate cancer (CRPC) and may drive progression through activation of the PI3K/AKT pathway. Here, we developed a novel CTC-based assay to determine PTEN status and examined the correlation between PTEN status in CTCs and matched tumour tissue samples. Methods: PTEN gene status in CTCs was evaluated on an enrichment-free platform (Epic Sciences) by fluorescence in situ hybridisation (FISH). PTEN status in archival and fresh tumour tissue was evaluated by FISH and immunohistochemistry. Results: Peripheral blood was collected from 76 patients. Matched archival and fresh cancer tissue was available for 48 patients. PTEN gene status detected in CTCs was concordant with PTEN status in matched fresh tissues and archival tissue in 32 of 38 patients (84%) and 24 of 39 patients (62%), respectively. CTC counts were prognostic (continuous, P=0.001). PTEN loss in CTCs associated with worse survival in univariate analysis (HR 2.05; 95% CI 1.17–3.62; P=0.01) and with high lactate dehydrogenase (LDH) in metastatic CRPC patients. Conclusions: Our results illustrate the potential use of CTCs as a non-invasive, real-time liquid biopsy to determine PTEN gene status. The prognostic and predictive value of PTEN in CTCs warrants investigation in CRPC clinical trials of PI3K/AKT-targeted therapies. PMID:26379078

  18. Inhibition of the HER2-YB1-AR axis with Lapatinib synergistically enhances Enzalutamide anti-tumor efficacy in castration resistant prostate cancer

    PubMed Central

    Shiota, Masaki; Bishop, Jennifer L.; Takeuchi, Ario; Nip, Ka Mun; Cordonnier, Thomas; Beraldi, Eliana; Kuruma, Hidetoshi; Gleave, Martin E.; Zoubeidi, Amina

    2015-01-01

    Incurable castration-resistant prostate cancer (CRPC) is driven by androgen receptor (AR) activation. Potent therapies that prevent AR signaling, such as Enzalutamide (ENZ), are mainstay treatments for CRPC; however patients eventually progress with ENZ resistant (ENZR) disease. In this study, we investigated one mechanism of ENZ resistance, and tried to improve therapeutic efficiency of ENZ. We found HER2 expression is increased in ENZR tumors and cell lines, and is induced by ENZ treatment of LNCaP cells. ENZ-induced HER2 overexpression was dependent on AKT-YB1 activation and modulated AR activity. HER2 dependent AR activation in LNCaP and ENZR cells was effectively blocked by treatment with the EGFR/HER2 inhibitor Lapatinib, which reduced cell viability and increased apoptosis. Despite efficacy in vitro, in vivo monotherapy with Lapatinib did not prevent ENZR tumor growth. However, combination treatment of Lapatinib with ENZ most effectively induced cell death in LNCaP cells in vitro and was more effective than ENZ alone in preventing tumor growth in an in vivo model of CRPC. These results suggest that while HER2 overexpression and subsequent AR activation is a targetable mechanism of resistance to ENZ, therapy using Lapatinib is only a rational therapeutic approach when used in combination with ENZ in CRPC. PMID:25871401

  19. Common Genetic Variation in CYP17A1 and Response to Abiraterone Acetate in Patients with Metastatic Castration-Resistant Prostate Cancer

    PubMed Central

    Binder, Moritz; Zhang, Ben Y.; Hillman, David W.; Kohli, Rhea; Kohli, Tanvi; Lee, Adam; Kohli, Manish

    2016-01-01

    Treatment with abiraterone acetate and prednisone (AA/P) prolongs survival in metastatic castration-resistant prostate cancer (mCRPC) patients. We evaluated the genetic variation in CYP17A1 as predictive of response to AA/P. A prospective collection of germline DNA prior to AA/P initiation and follow-up of a mCRPC cohort was performed. Five common single-nucleotide polymorphisms (SNPs) in CYP17A1 identified using a haplotype-based tagging algorithm were genotyped. Clinical outcomes included biochemical response and time to biochemical progression on AA/P. Logistic regression was used to assess the association between tag SNPs and biochemical response. Proportional hazards regression was used to assess the association between tag SNPs and time to biochemical progression. Odds or hazard ratio per minor allele were estimated and p-values below 0.05 were considered statistically significant. Germline DNA was successfully genotyped for four tag SNPs in 87 patients. The median age was 73 years (54–90); the median prostate-specific antigen was 66 ng/dL (0.1–99.9). A single SNP, rs2486758, was associated with lower odds of experiencing a biochemical response (Odds ratio 0.22, 95% confidence interval 0.07–0.63, p = 0.005) and a shorter time to biochemical progression (Hazard ratio 2.23, 95% confidence interval 1.39–3.56, p < 0.001). This tag SNP located in the promoter region of CYP17A1 will need further validation as a predictive biomarker for AA/P therapy. PMID:27409606

  20. A randomised phase 2 study combining LY2181308 sodium (survivin antisense oligonucleotide) with first-line docetaxel/prednisone in patients with castration-resistant prostate cancer.

    PubMed

    Wiechno, Paweł; Somer, Bradley G; Mellado, Begoña; Chłosta, Piotr L; Cervera Grau, José Manuel; Castellano, Daniel; Reuter, Christoph; Stöckle, Michael; Kamradt, Jörn; Pikiel, Joanna; Durán, Ignacio; Wedel, Steffen; Callies, Sophie; André, Valérie; Hurt, Karla; Brown, Jacqueline; Lahn, Michael; Heinrich, Bernhard

    2014-03-01

    Castration-resistant prostate cancer (CRPC) is partially characterised by overexpression of antiapoptotic proteins, such as survivin. In this phase 2 study, patients with metastatic CRPC (n=154) were randomly assigned (1:2 ratio) to receive standard first-line docetaxel/prednisone (control arm) or the combination of LY2181308 with docetaxel/prednisone (experimental arm). The primary objective was to estimate progression-free survival (PFS) for LY2181308 plus docetaxel. Secondary efficacy measures included overall survival (OS), several predefined prostate-specific antigen (PSA)-derived end points, and Brief Pain Inventory (BPI) and Functional Assessment of Cancer Therapy-Prostate (FACT-P) scores. The median PFS of treated patients for the experimental arm (n=98) was 8.64 mo (90% confidence interval [CI], 7.39-10.45) versus 9.00 mo (90% CI, 7.00-10.09) in the control arm (n=51; p=0.755). The median OS for the experimental arm was 27.04 mo (90% CI, 19.94-33.41) compared with 29.04 mo (90% CI, 20.11-39.26; p=0.838). The PSA responses (≥ 50% PSA reduction), BPI, and FACT-P scores were similar in both arms. In the experimental arm, patients had a numerically higher incidence of grades 3-4 neutropenia, anaemia, thrombocytopenia, and sensory neuropathy. In conclusion, this study failed to detect a difference in efficacy between the two treatment groups. Copyright © 2013 European Association of Urology. Published by Elsevier B.V. All rights reserved.

  1. Second-Line Hormonal Therapy for Men With Chemotherapy-Naïve, Castration-Resistant Prostate Cancer: American Society of Clinical Oncology Provisional Clinical Opinion.

    PubMed

    Virgo, Katherine S; Basch, Ethan; Loblaw, D Andrew; Oliver, Thomas K; Rumble, R Bryan; Carducci, Michael A; Nordquist, Luke; Taplin, Mary-Ellen; Winquist, Eric; Singer, Eric A

    2017-06-10

    Purpose ASCO provisional clinical opinions (PCOs) offer direction to the ASCO membership after publication or presentation of potential practice-changing data. This PCO addresses second-line hormonal therapy for chemotherapy-naïve men with castration-resistant prostate cancer (CRPC) who range from being asymptomatic with only biochemical evidence of CRPC to having documented metastases but minimal symptoms. Clinical Context The treatment goal for CRPC is palliation. Despite resistance to initial androgen deprivation therapy, most men respond to second-line hormonal therapies. However, guidelines have neither addressed second-line hormonal therapy for nonmetastatic CRPC nor provided specific guidance with regard to the chemotherapy-naïve population. Recent Data Six phase III randomized controlled trials and expert consensus opinion inform this PCO. Provisional Clinical Opinion For men with CRPC, a castrate state should be maintained indefinitely. Second-line hormonal therapy (eg, antiandrogens, CYP17 inhibitors) may be considered in patients with nonmetastatic CRPC at high risk for metastatic disease (rapid prostate-specific antigen doubling time or velocity) but otherwise is not suggested. In patients with radiographic evidence of metastases and minimal symptoms, enzalutamide or abiraterone plus prednisone should be offered after discussion with patients about potential harms, benefits, costs, and patient preferences. Radium-223 and sipuleucel-T also are options. No evidence provides guidance about the optimal order of hormonal therapies for CRPC beyond second-line treatment. Prostate-specific antigen testing every 4 to 6 months is reasonable for men without metastases. Routine radiographic restaging generally is not suggested but can be considered for patients at risk for metastases or who exhibit symptoms or other evidence of progression. Additional information is available at www.asco.org/genitourinary-cancer-guidelines and www.asco.org/guidelineswiki .

  2. Nuclear factor-kappa B and interleukin-6 related docetaxel resistance in castration-resistant prostate cancer.

    PubMed

    Codony-Servat, Jordi; Marín-Aguilera, Mercedes; Visa, Laura; García-Albéniz, Xabier; Pineda, Estela; Fernández, Pedro L; Filella, Xavier; Gascón, Pere; Mellado, Begoña

    2013-04-01

    Previous work showed that the NF-κB survival pathway is activated by docetaxel (D) and contributes to D resistance in prostate cancer. In this study we aimed to investigate the dynamics of the relationship between NF-κB and IL-6 in the shift from D-naive castration-resistant prostate cancer (CRPC) to D-resistance in patients and cell lines. CRPC tumor samples were tested for NF-κB/p65 and IL-6 by immunohistochemistry. CRPC patients treated with D were also tested for serum IL-6 (ELISA). Two D-resistant cell lines, PC-3R and DU-145R, derived from the CRPC cells PC-3 and DU-145, respectively, were tested for NF-κB activation (EMSA), NF-κB-related genes expression (RT-PCR), NF-κB inhibition (p65 siRNA) and IL-6 and IL-8 soluble levels (ELISA). In CRPC patients treated with D (n = 72), pre-treatment IL-6 level correlated with nuclear NF-κB/p65 tumor staining and response to D, and was an independent prognostic factor for overall survival. However, IL-6 level changes under treatment did not correlate with clinical outcome. In PC-3 and DU-145 parental CRPC cells, as well as in D-resistant counterparts, D treatment induced NF-κB activation. In fact, NF-κB inhibition was sufficient to re-sensitize DU-145R cells to D. Despite enhanced NF-κB activity, IL-6 secretion in D-resistant cell lines was reduced and not induced by D treatment. The same occurred with IL-8 cytokine. These preclinical and clinical results support a role of NF-κB and IL-6 in the resistance to D in CRPC, and support the investigation of targeted therapies to enhance the antitumor activity of D in this patient population. Copyright © 2012 Wiley Periodicals, Inc.

  3. Clinical outcomes and survival surrogacy studies of prostate-specific antigen declines following enzalutamide in men with metastatic castration-resistant prostate cancer previously treated with docetaxel.

    PubMed

    Armstrong, Andrew J; Saad, Fred; Phung, De; Dmuchowski, Carl; Shore, Neal D; Fizazi, Karim; Hirmand, Mohammad; Forer, David; Scher, Howard I; Bono, Johann De

    2017-06-15

    In the AFFIRM trial, enzalutamide significantly increased overall survival (OS) for men with metastatic castration-resistant prostate cancer (mCRPC) after chemotherapy versus placebo and significantly decreased prostate-specific antigen (PSA) levels. The goal of this post hoc analysis was to associate levels of PSA decline from baseline after enzalutamide with clinical outcomes in the postchemotherapy mCRPC setting. Men in the AFFIRM trial (n = 1199) were grouped by maximal PSA decline in the first 90 days of treatment. Kaplan-Meier estimates evaluated the association of defined PSA changes from baseline with OS, progression-free survival (PFS), radiographic PFS (rPFS), and pain response. Each PSA decline category was assessed for OS surrogacy using Prentice criteria, proportion of treatment effect explained (PTE), and proportion of variation explained. Men treated with enzalutamide had improved OS (hazard ratio, 0.63; P < .001) and higher rates of PSA decline (odds ratio, >19.0; P < .001) versus placebo. PSA declines of any, ≥30%, ≥50%, and ≥90% with enzalutamide were strongly associated with greater OS, PSA PFS, rPFS (P < .001), and pain response (P < .026) versus PSA increase/no decline. Any, ≥30%, and ≥50% declines in PSA resulted in the PTE range of 1.07-1.29, where treatment was no longer significant after adjustment for decline measures (P > .20). PSA declines of any, ≥30%, and ≥50% following enzalutamide were associated with greater clinical and pain response and improvements in PFS and OS. Surrogacy of PSA decline for OS was not fully established, possibly due to lack of PSA declines with placebo, and discordant results between PSA and imaging responses over time, and because some declines were not durable due to rapid resistance development. However, a lack of PSA decline by 90 days following enzalutamide treatment was a poor prognosis indicator in this setting. Co