Leveraging RB status to define therapy for castrate-resistant prostate cancer.

2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 96-96
Author(s):  
Renee de Leeuw ◽  
Clay de Comstock ◽  
Daniela de Pollutri ◽  
Matthew Joseph Schiewer ◽  
Stephen J Ciment ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Kinase Inhibitors ◽  
Ex Vivo ◽  
Tissue Samples ◽  
Ki67 Staining ◽  
Cell Architecture ◽  
Castrate Resistant Prostate Cancer ◽  
Castrate Resistant

96 Background: Loss of retinoblastoma (RB) tumor suppressor is overrepresented in castrate-resistant prostate cancer (CRPC) compared to primary PCa. We previously showed using analyses of human tissue and in vitro and in vivo modeling that RB constrains androgen receptor (AR) function, and that loss of RB is sufficient promote resistance to castration and AR antagonists. Thus, novel strategies are needed to treat RB-deficient tumor. By contrast, in tumors retaining RB, suppressing enhancing RB activity would be of therapeutic advantage, and may be accomplished through next-generation Cdk4/6 inhibitors. Methods: Stable isogenic pairs of prostate cancer cell lines either retaining RB or RB depleted (by shRNA) were assessed in vitro and in xenografts for response to Cdk4/6 kinase inhibitors or the cabazitaxel. In addition, using an ex vivo explant assay, fresh tumor tissue samples from radical prostatectomy were exposed to the Cdk4/6 inhibitor or cabazitaxel for up to 7 days, and evaluated by IHC for Ki67, Caspase-3, and AR. Results: Cdk4/6 inhibition blocks tumor cell proliferation dependent on RB status. This was further confirmed ex vivo, as evidenced by a marked reduction in Ki67 staining in Cdk4/6 inhibitor treated explant tissue from two prostate cancer patients. Conversely, in vitro studies revealed a modest sensitization of RB-depleted tumors to cabazitaxel that was dramatically enhanced in vivo and after castration. Cabazitaxel, like docetaxel, targets the cell architecture and induces cell death, but also induces a distinct gene expression profile that may partially explain efficacy in docetaxel-resistant tumors. Neither taxane showed affects on AR nuclear localization using in vivoor explant studies. Conclusions: These results strongly support our hypothesis that RB status can be used as a metric to define therapeutic response to cabazitaxel, as such that loss of RB function induces sensitization taxanes, whereas RB proficient tumors give an enhanced response to Cdk4/6 kinase inhibitors.

scholarly journals Effect of Combination therapy of Desmopressin and Docetaxel on prostate cancer cell DU145 proliferation, migration and growth

2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Azik Hoffman ◽  
Hiroshi Sasaki ◽  
Domenica Roberto ◽  
Michelle J Mayer ◽  
Laurence Klotz ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Wound Healing ◽  
Combination Therapy ◽  
Tumor Volume ◽  
Prostate Cancer Cell ◽  
Wound Healing Assay ◽  
Castrate Resistant Prostate Cancer ◽  
Castrate Resistant

Background: This study was designed to assess the efficacy of the combination of Desmopressin and Docetaxel for prostate cancer. Desmopressin has been demonstrated to inhibit tumor progression and metastasis in in vitro and in vivo models of breast cancer. Docetaxel, an anti-mitotic chemotherapeutic agent, is widely used for the treatment of castration resistant prostate cancer. However, it is associated with adverse effects and eventual drug resistance. This is the first report on the effect of combining Desmopressin and Docetaxel in prostate cancer, both in vitro and in vivo. Methods: An established castrate resistant prostate cancer cell line DU145 was used. Cellular proliferation was determined using the MTS assay. The migratory inhibition potential of Desmopressin alone and in combination with Docetaxel was accessed using the wound healing assay. In vivo evaluation was performed on a prostate cancer xenograft model using athymic nude mouse. Treatment was administered bi- weekly and tumor volume were measured throughout the treatment period. Eventually, after a six-week treatment period, tumors were excised and measured.  Results: A combination therapy of 1 µM Desmopressin with 100nM Docetaxel resulted in dramatic inhibition of proliferation of DU145 cells 72 hours post treatment compared to either agent along (p < 0.05). Wound healing assay revealed inhibition of cellular migration as well (p<0.05). The use of a xenograft mouse model followed by treatment with 5 mg/kg Docetaxel intraperitoneally with concomitant 2 µg/ml/kg Desmopressin administered intravenously 30 minutes before administering chemotherapy and 24 hours after, resulted in a significant decrease in tumor volume (P<0.05), while not impacting body weight.Conclusions: Desmopressin significantly enhanced the anti-proliferative and inhibiting the migratory potential of Docetaxel. Combination treatment had no additional effect on mice weight or mortality. These studies could enhance the efficacy of Docetaxel- based chemotherapy treatment for castrate resistant prostate cancer.

Characterisation of CCS1477: A novel small molecule inhibitor of p300/CBP for the treatment of castration resistant prostate cancer.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 11590-11590 ◽  
Author(s):  
Neil Pegg ◽  
Nigel Brooks ◽  
Jenny Worthington ◽  
Barbara Young ◽  
Amy Prosser ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Prostate Cell ◽  
Molecule Inhibitor ◽  
Castrate Resistant Prostate Cancer ◽  
Castrate Resistant ◽  
And Function ◽  
Prostate Cell Lines

11590 Background: Targeted degradation of androgen receptor (AR) and AR variants (ARV) remains an attractive therapeutic opportunity for patients with castrate resistant prostate cancer (CRPC). E1A binding protein (p300) and CREB binding protein (CBP) are two closely related transcriptional activators of AR. We have developed CCS1477 which is a potent, selective and orally active small molecule inhibitor of the bromodomain of p300/CBP and investigated its role in regulating androgen receptor expression and function. Methods: Binding of CCS1477 to p300, CBP and BRD4, was measured in a surface plasmon resonance (SPR) assay. Potency and functional activity (proliferation and biomarker knockdown) was demonstrated in prostate cell lines in vitro (22Rv1, VCaP). Cross species in vivo pharmacokinetic (PK) properties were assessed, and in vivo efficacy, linked to inhibition of biomarkers, was determined in 22Rv1 and LNCaP xenograft models. Results: CCS1477 binds to p300 and CBP with high affinity (Kd = 1.3/1.7nM) and selectivity (Kd = 222nM; BRD4). It is a potent inhibitor of cell proliferation in prostate cell lines (IC50 = 96nM,22Rv1; 49nM,VCaP) with minimal effect in AR-ve lines. In 22Rv1 cells, p300/CBP inhibition down-regulates AR-FL, AR-V7 and c-Myc protein by Western, an effect not seen with the BET inhibitor, JQ1 at equivalent proliferation IC50s. Inhibition of p300/CBP also reduces c-Myc, KLK3 and TMPRSS2 gene expression (qPCR) in 22Rv1 cells in vitro. The in vivo PK properties of CCS1477 are consistent with qd or qod oral dosing in mouse. CCS1477 dosed at 10mg, 20mg/kg qd or 30mg/kg qod, caused complete tumour growth inhibition over 28 days in a 22RV1 xenograft model, including extended duration in the absence of the drug for a further 24 days. This was accompanied by complete inhibition of plasma PSA and significant knockdown of tumour AR-FL, AR-V7, and C-Myc protein as well as C-Myc and TMPRSS2 mRNA expression. Conclusions: Taken together these data support the clinical testing of CCS1477 in castrate resistant prostate cancer by down-regulation of AR, AR-SV and c-MYC expression and function.

Anticancer activity of the selective CYP17A1 inhibitor, VT-464, in preclinical models of castrate-resistant prostate cancer.

2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 104-104 ◽  
Author(s):  
Paul Toren ◽  
Steven Pham ◽  
Soojin Kim ◽  
Hans Adomat ◽  
Amina Zoubeidi ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cell Lines ◽  
Xenograft Model ◽  
Resistant Cell ◽  
Anti Cancer ◽  
Castrate Resistant Prostate Cancer ◽  
Castrate Resistant ◽  
Cancer Activity

104 Background: Castrate resistant prostate cancer (CRPC) continues to be sensitive to anti-androgen therapy as evidenced by the recent successes of abiraterone acetate (AA) and enzalutamide (ENZ). VT-464 is a novel, non-steroidal, small molecule CYP17A1 inhibitor with selectivity for the lyase activity of this dual enzyme. The objective of this study was to evaluate the anti-cancer activity of VT-464 compared to AA in CRPC in vitro models that are ENZ-responsive and ENZ-resistant and in an ENZ-resistant xenograft model. Methods: In vitro studies used the human CRPC, C4-2, and ENZ-resistant cell lines, MR49C and MR49F cells, in androgen-free media. AR transcriptional activity was assessed by probasin luciferase. AR-related and steroidogenesis pathways were assessed by western blot and/or qRT-PCR. A MR49F xenograft model in castrate mice compared oral VT-464 treatment to vehicle and AA. Steroid concentrations were measured using LC-MS chromatography. Results: VT-464 demonstrated a greater decrease in AR transactivation compared to AA in C4-2 and both ENZ-resistant cell lines. A greater decrease in AR-dependent gene transcription occurred with VT-464 treatment compared to AA in all cell lines. Prostate-specific antigen (PSA) protein levels in vitro were also lower with VT-464. Gene transcripts StAR, CYP17A1, HSD17B3 and SRD5A1 increased following treatment with VT-464 both in vitro and in vivo. A greater increase was seen with VT-464 treatment compared to AA. In vivo results demonstrated greater tumor growth inhibition and decreased serum PSA levels in mice treated with oral VT-464 compared to AA. Steroid analysis revealed lower testosterone (T) and dihydrotestosterone (DHT) concentrations in C4-2 cells with VT-464 treatment compared to AA. In vivo, the intra-tumoral DHT and T levels were significantly lower in response to VT-464 or AA compared to vehicle, with the greatest decrease seen with VT-464. Conclusions: The selective CYP17 inhibitor VT-464 demonstrated anti-cancer activity in pre-clinical models of CRPC, lowering intratumoral T and DHT concentrations significantly in castrate mice. These results suggest greater androgen suppression and inhibition of AR axis signaling by VT-464 than by AA.

scholarly journals Computational modeling identifies multitargeted kinase inhibitors as effective therapies for metastatic, castration-resistant prostate cancer

2021 ◽  
Vol 118 (40) ◽  
pp. e2103623118
Author(s):  
Thomas Bello ◽  
Claudia Paindelli ◽  
Luis A. Diaz-Gomez ◽  
Anthony Melchiorri ◽  
Antonios G. Mikos ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Computational Modeling ◽  
Late Stage ◽  
Kinase Inhibitors ◽  
Ex Vivo ◽  
Growth Factor Signaling ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant

Castration-resistant prostate cancer (CRPC) is an advanced subtype of prostate cancer with limited therapeutic options. Here, we applied a systems-based modeling approach called kinome regularization (KiR) to identify multitargeted kinase inhibitors (KIs) that abrogate CRPC growth. Two predicted KIs, PP121 and SC-1, suppressed CRPC growth in two-dimensional in vitro experiments and in vivo subcutaneous xenografts. An ex vivo bone mimetic environment and in vivo tibia xenografts revealed resistance to these KIs in bone. Combining PP121 or SC-1 with docetaxel, standard-of-care chemotherapy for late-stage CRPC, significantly reduced tibia tumor growth in vivo, decreased growth factor signaling, and vastly extended overall survival, compared to either docetaxel monotherapy. These results highlight the utility of computational modeling in forming physiologically relevant predictions and provide evidence for the role of multitargeted KIs as chemosensitizers for late-stage, metastatic CRPC.

scholarly journals In vitro engineering of a bone metastases model allows for study of the effects of antiandrogen therapies in advanced prostate cancer

2021 ◽  
Vol 7 (27) ◽  
pp. eabg2564
Author(s):  
Nathalie Bock ◽  
Thomas Kryza ◽  
Ali Shokoohmand ◽  
Joan Röhl ◽  
Akhilandeshwari Ravichandran ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cancer Progression ◽  
Advanced Prostate Cancer ◽  
Adaptive Responses ◽  
Metastatic Tissue ◽  
Metastatic Lesions ◽  
Castrate Resistant Prostate Cancer ◽  
Castrate Resistant

While androgen-targeted therapies are routinely used in advanced prostate cancer (PCa), their effect is poorly understood in treating bone metastatic lesions and ultimately results in the development of metastatic castrate resistant prostate cancer (mCRPC). Here, we used an all-human microtissue-engineered model of mineralized metastatic tissue combining human osteoprogenitor cells, 3D printing and prostate cancer cells, to assess the effects of the antiandrogens, bicalutamide, and enzalutamide in this microenvironment. We demonstrate that cancer/bone stroma interactions and antiandrogens drive cancer progression in a mineralized microenvironment. Probing the bone microenvironment with enzalutamide led to stronger cancer cell adaptive responses and osteomimicry than bicalutamide. Enzalutamide presented with better treatment response, in line with enzalutamide delaying time to bone-related events and enzalutamide extending survival in mCRPC. The all-human microtissue-engineered model of mineralized metastatic tissue presented here represents a substantial advance to dissect the role of the bone tumor microenvironment and responses to therapies for mCPRC.

scholarly journals Conditionally Reprogrammed Cells from Patient-Derived Xenograft to Model Neuroendocrine Prostate Cancer Development

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1398 ◽  
Author(s):  
Xinpei Ci ◽  
Jun Hao ◽  
Xin Dong ◽  
Hui Xue ◽  
Rebecca Wu ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Ex Vivo ◽  
Cancer Cell Line ◽  
Marker Genes ◽  
Patient Derived Xenograft ◽  
Pdx Model ◽  
Neuroendocrine Prostate Cancer ◽  
Parental Tumor

Neuroendocrine prostate cancer (NEPC) is a lethal subtype of prostate cancer. It develops mainly via NE transdifferentiation of prostate adenocarcinoma in response to androgen receptor (AR)-inhibition therapy. The study of NEPC development has been hampered by a lack of clinically relevant models. We previously established a unique and first-in-field patient-derived xenograft (PDX) model of adenocarcinoma (LTL331)-to-NEPC (LTL331R) transdifferentiation. In this study, we applied conditional reprogramming (CR) culture to establish a LTL331 PDX-derived cancer cell line named LTL331_CR_Cell. These cells retain the same genomic mutations as the LTL331 parental tumor. They can be continuously propagated in vitro and can be genetically manipulated. Androgen deprivation treatment on LTL331_CR_Cells had no effect on cell proliferation. Transcriptomic analyses comparing the LTL331_CR_Cell to its parental tumor revealed a profound downregulation of the androgen response pathway and an upregulation of stem and basal cell marker genes. The transcriptome of LTL331_CR_Cells partially resembles that of post-castrated LTL331 xenografts in mice. Notably, when grafted under the renal capsules of male NOD/SCID mice, LTL331_CR_Cells spontaneously gave rise to NEPC tumors. This is evidenced by the histological expression of the NE marker CD56 and the loss of adenocarcinoma markers such as PSA. Transcriptomic analyses of the newly developed NEPC tumors further demonstrate marked enrichment of NEPC signature genes and loss of AR signaling genes. This study provides a novel research tool derived from a unique PDX model. It allows for the investigation of mechanisms underlying NEPC development by enabling gene manipulations ex vivo and subsequent functional evaluations in vivo.

scholarly journals Bone-Targeted Therapies in Metastatic Castration-Resistant Prostate Cancer: Evolving Paradigms

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Joelle El-Amm ◽  
Ashley Freeman ◽  
Nihar Patel ◽  
Jeanny B. Aragon-Ching
Keyword(s):  
Prostate Cancer ◽  
Bone Metastases ◽  
Kinase Inhibitors ◽  
Targeted Agents ◽  
Pain Palliation ◽  
Castration Resistant Prostate Cancer ◽  
Humanized Monoclonal Antibody ◽  
Castrate Resistant Prostate Cancer ◽  
Castrate Resistant ◽  
Overall Survival Benefit

Majority of patients with metastatic castrate resistant prostate cancer (mCRPC) develop bone metastases which results in significant morbidity and mortality as a result of skeletal-related events (SREs). Several bone-targeted agents are either in clinical use or in development for prevention of SREs. Bisphosphonates were the first class of drugs investigated for prevention of SREs and zoledronic acid is the only bisphosphonate that is FDA-approved for this indication. Another bone-targeted agent is denosumab which is a fully humanized monoclonal antibody that binds to the RANK-L thereby inhibiting RANK-L mediated bone resorption. While several radiopharmaceuticals were approved for pain palliation in mCRPC including strontium and samarium, alpharadin is the first radiopharmaceutical to show significant overall survival benefit. Contemporary therapeutic options including enzalutamide and abiraterone have effects on pain palliation and SREs as well. Other novel bone-targeted agents are currently in development, including the receptor tyrosine kinase inhibitors cabozantinib and dasatinib. Emerging therapeutics in mCRPC has resulted in great strides in preventing one of the most significant sources of complications of bone metastases.

scholarly journals MINDIN secretion by prostate tumors induces premetastatic changes in bone via β-catenin

2020 ◽  
Vol 27 (7) ◽  
pp. 441-456
Author(s):  
Juan A Ardura ◽  
Luis Álvarez-Carrión ◽  
Irene Gutiérrez-Rojas ◽  
Peter A Friedman ◽  
Arancha R Gortázar ◽  
...  
Keyword(s):  
Gene Expression ◽  
Prostate Cancer ◽  
Tumor Cell ◽  
Ex Vivo ◽  
Prostate Tumor ◽  
Tumor Cell Adhesion ◽  
Prostate Tumors ◽  
Cell Homing

Bone metastases are common in advanced prostate cancer patients, but mechanisms by which specific pro-metastatic skeletal niches are formed before tumor cell homing are unclear. We aimed to analyze the effects of proteins secreted by primary prostate tumors on the bone microenvironment before the settlement and propagation of metastases. Here, using an in vivo pre-metastatic prostate cancer model based on the implantation of prostate adenocarcinoma TRAMP-C1 cells in immunocompetent C57BL/6 mice, we identify MINDIN as a prostate tumor secreted protein that induces bone microstructural and bone remodeling gene expression changes before tumor cell homing. Associated with these changes, increased tumor cell adhesion to the endosteum ex vivo and to osteoblasts in vitro was observed. Furthermore, MINDIN promoted osteoblast proliferation and mineralization and monocyte expression of osteoclast markers. β-catenin signaling pathway revealed to mediate MINDIN actions on osteoblast gene expression but failed to affect MINDIN-induced adhesion to prostate tumor cells or monocyte differentiation to osteoclasts. Our study evidences that MINDIN secretion by primary prostate tumors creates a favorable bone environment for tumor cell homing before metastatic spread.

scholarly journals Upregulated Wnt-11 and miR-21 Expression Trigger Epithelial Mesenchymal Transition in Aggressive Prostate Cancer Cells

Biology ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 52 ◽  
Author(s):  
Elif Damla Arisan ◽  
Ozge Rencuzogullari ◽  
Ines Lua Freitas ◽  
Syanas Radzali ◽  
Buse Keskin ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Epithelial Mesenchymal Transition ◽  
Significant Inhibition ◽  
Developmentally Regulated ◽  
Tissue Samples ◽  
Mesenchymal Transition ◽  
Formalin Fixed Paraffin ◽  
Signaling Axis

Prostate cancer (PCa) is the second-leading cause of cancer-related death among men. microRNAs have been identified as having potential roles in tumorigenesis. An oncomir, miR-21, is commonly highly upregulated in many cancers, including PCa, and showed correlation with the Wnt-signaling axis to increase invasion. Wnt-11 is a developmentally regulated gene and has been found to be upregulated in PCa, but its mechanism is unknown. The present study aimed to investigate the roles of miR-21 and Wnt-11 in PCa in vivo and in vitro. First, different Gleason score PCa tissue samples were used; both miR-21 and Wnt-11 expressions correlate with high Gleason scores in PCa patient tissues. This data then was confirmed with formalin-fixed paraffin cell blocks using PCa cell lines LNCaP and PC3. Cell survival and colony formation studies proved that miR-21 involves in cells’ behaviors, as well as the epithelial-mesenchymal transition. Consistent with the previous data, silencing miR-21 led to significant inhibition of cellular invasiveness. Overall, these results suggest that miR-21 plays a significant role related to Wnt-11 in the pathophysiology of PCa.

Phase I trial of anti-PSMA designer T-cell autografting in prostate cancer

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e16132-e16132
Author(s):  
M. Abedi ◽  
Q. Ma ◽  
A. Bais ◽  
E. Gomes ◽  
E. Beaudoin ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Clinical Trial ◽  
T Cells ◽  
T Cell ◽  
Phase I ◽  
Ex Vivo ◽  
Immune Therapy ◽  
Us Army

e16132 Background: We created chimeric immunoglobulin-T cell receptors (IgTCR) specific for prostate specific membrane antigen (PSMA). When expressed in patient T cells, these “designer T cells” specifically kill prostate cancer cells in vitro and in vivo in animal models, with 5/9 (55%) of xenografted mice experiencing complete remissions (Ma et al. Prostate 2004:61:12–25). A Phase I clinical trial was approved by the FDA in metastatic prostate cancers. Methods: Patient T cells are retrovirally transduced and expanded ex vivo to span dose levels of 10^9 to 10^11 T cells. Adapting methods of Dudley, Rosenberg and colleagues, patients undergo prior non-myeloablative (NMA) conditioning to create a “hematologic space” into which the infused designer T cells will stably engraft for prolonged in vivo efficacy. Patients are co-administered continuous infusion IL2. Outcomes will include Phase Ia goals of safety and toxicity and Phase Ib goals of establishing an optimal biologic dose in terms of designer T cell engraftment and tumor response. Results: For the first two patients, excellent T cell modifications of 50–60% were obtained. After NMA conditioning, T cells were infused and stable engraftments of 1–5% were observed post recovery, even at this lowest 10^9 T cell dose level, thus affirming one of the study end-points. The patients had PSA reductions of 50 and 70% in the two months following treatment. Patients experienced neutropenia and lymphopenia after conditioning, but no designer T cell-related toxicities. Results with additional patients will be described in terms of safety, engraftment efficiency and tumor responses. Conclusions: A new approach to adoptive immune therapy in metastatic prostate cancer has been devised. This clinical trial is funded by the US Army/DOD. No significant financial relationships to disclose.

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