ARV-330: Androgen receptor PROTAC degrader for prostate cancer.

2016 ◽  
Vol 34 (2_suppl) ◽  
pp. 267-267 ◽  
Author(s):  
Taavi K Neklesa ◽  
Meizhong Jin ◽  
Andrew P Crew ◽  
AnnMarie K Rossi ◽  
Ryan R Willard ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Therapeutic Effects ◽  
Preclinical Development ◽  
Protein Levels ◽  
Novel Approach ◽  
Subsequent Degradation ◽  
20 Nm

267 Background: The transition from localized prostate cancer to metastatic disease often involves modulation of the Androgen Receptor (AR). During the disease progression, patients progressing on enzalutamide or abiraterone therapy exhibit amplified AR, increased intra-tumoral androgen production or AR mutations leading to promiscuity to other ligands. Therefore, AR is still the principal driver of the disease. Methods: A novel approach to block AR signaling is to specifically target AR for degradation. To this end, we have developed the PROteolysis TArgeting Chimera (PROTAC) technology that employs hetero-bifunctional small molecules that simultaneously bind VHL E3 ubiquitin ligase and a target of interest (e.g. AR). Due to induced proximity between VHL and AR, an AR PROTAC leads to ubiquitination and subsequent degradation of AR. Results: Our lead AR PROTAC, ARV-330, degrades 92-98% of total AR in all cell lines tested, with 50% degradation concentrations (DC50) < 1nM. AR degradation suppresses the AR-target gene PSA expression, inhibits proliferation, and induces potent apoptosis in VCaP cells with maximal apoptosis observed at 20 nM. While enzalutamide loses its activity in the presence of > 0.5 nM R1881, ARV-330 maintains its activity. In cells containing the ARF876L mutation, enzalutamide is an agonist; however, ARV-330 remains effective. In fact, ARV-330 is able to degrade all clinically relevant AR mutations. ARV-330 exhibits good pharmacokinetic properties, with t1/2 values of several hours and bioavailability of > 80% after sc injection. Treatment of mice with ARV-330, at doses ranging from 0.3 to 10 mg/kg, results in reduction of AR protein levels. The in vitro potency translates into in vivo efficacy, as ARV-330 demonstrates prostate involution in intact mice. In castrated mice implanted with VCaP tumors, ARV-330 shows robust reduction of plasma PSA and blockade of tumor growth. Conclusions: In summary, the AR PROTAC ARV-330 removes AR from prostate cancer cells in a potent manner and produces therapeutic effects as a result. This cellular efficacy has translated into biomarker activity and efficacy in animal models, and ARV-330 is now in preclinical development.

scholarly journals Inhibition of Androgen Receptor Transcriptional Activity as a Novel Mechanism of Action of Arsenic

2009 ◽  
Vol 23 (3) ◽  
pp. 412-421 ◽  
Author(s):  
Adena E. Rosenblatt ◽  
Kerry L. Burnstein
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Male Infertility ◽  
Transcriptional Activity ◽  
Target Gene ◽  
Nuclear Translocation ◽  
Therapeutic Option ◽  
Protein Levels

Abstract Environmental sodium arsenite is a toxin that is associated with male infertility due to decreased and abnormal sperm production. Arsenic trioxide (ATO), another inorganic trivalent semimetal, is an effective therapy for acute promyelocytic leukemia, and there is investigation of its possible efficacy in prostate cancer. However, the mechanism of arsenic action in male urogenital tract tissues is not clear. Because the androgen receptor (AR) plays an important role in spermatogenesis and prostate cancer, we explored the possibility that trivalent arsenic regulates AR function. We found that arsenic inhibited AR transcriptional activity in prostate cancer and Sertoli cells using reporter gene assays testing several androgen response element-containing regions and by assessing native target gene expression. Arsenic inhibition of AR activity was not due to down-regulation of AR protein levels, decreased hormone binding to AR, disruption of AR nuclear translocation, or interference with AR-DNA binding in vitro. However, chromatin immunoprecipitation studies revealed that arsenic inhibited AR recruitment to an AR target gene enhancer in vivo. Consistent with a deficiency in AR-chromatin binding, arsenic disrupted AR amino and carboxyl termini interaction. Furthermore, ATO caused a significant decrease in prostate cancer cell proliferation that was more pronounced in cells expressing AR compared with cells depleted of AR. In addition, inhibition of AR activity by ATO and by the AR antagonist, bicalutamide, was additive. Thus, arsenic-induced male infertility may be due to inhibition of AR activity. Further, because AR is an important target in prostate cancer therapy, arsenic may serve as an effective therapeutic option.

scholarly journals Human Adrenomedullin Up-regulates Interleukin-13 Receptor α2 Chain in Prostate Cancer In vitro and In vivo: A Novel Approach to Sensitize Prostate Cancer to Anticancer Therapy

2008 ◽  
Vol 68 (22) ◽  
pp. 9311-9317 ◽  
Author(s):  
Bharat H. Joshi ◽  
Pamela Leland ◽  
Alfonso Calvo ◽  
Jeffrey E. Green ◽  
Raj K. Puri
Keyword(s):  
Prostate Cancer ◽  
Anticancer Therapy ◽  
Interleukin 13 ◽  
Novel Approach

scholarly journals Interleukin-6 stimulation of growth of prostate cancer in vitro and in vivo through activation of the androgen receptor

2009 ◽  
Vol 16 (1) ◽  
pp. 155-169 ◽  
Author(s):  
Kamilla Malinowska ◽  
Hannes Neuwirt ◽  
Ilaria T Cavarretta ◽  
Jasmin Bektic ◽  
Hannes Steiner ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Interleukin 6 ◽  
Tumour Progression ◽  
Receptor Activity ◽  
Mitogen Activated Protein Kinase ◽  
Androgen Receptor Activity ◽  
Stimulation Of

It is hypothesized that ligand-independent activation of the androgen receptor is one of the mechanisms implicated in tumour progression. However, supportive evidence is limited to the effect of HER-2/neu that stimulates prostate cancer progression through activation of the androgen receptor. In the present study, we have asked whether the proinflammatory cytokine interleukin-6 (IL-6), which is known to stimulate androgen receptor activity and expression of its downstream target genes, may also induce growth of androgen-sensitive cells. We have found that IL-6 differentially regulates proliferation of LAPC-4 and MDA PCa 2b cells. In MDA PCa 2b cells, growth stimulation by IL-6 was reversed by administration of either the non-steroidal anti-androgen bicalutamide or the inhibitor of the mitogen-activated protein kinase pathway PD98059. Neither cell line was found to express endogenous IL-6. Interestingly, the treatment of those prostate cancer cells did not increase phosphorylation of STAT3. The effect of IL-6 on stimulation of androgen receptor activity in MDA PCa 2b cells was lower than that of androgen, comparable with findings reported by other researchers. However, growth of MDA PCa 2b xenografts in castrated animals treated with IL-6 was similar to that in non-castrated animals. In addition, bicalutamide showed an inhibitory effect on IL-6-regulated growth in vivo. Taken together, data in the present study demonstrate that IL-6 may cause growth of androgen receptor-positive tumours in vitro and in vivo through activation of the androgen receptor.

scholarly journals The PPARγ ligand rosiglitazone attenuates hypoxia-induced endothelin signaling in vitro and in vivo

2011 ◽  
Vol 301 (6) ◽  
pp. L881-L891 ◽  
Author(s):  
Bum-Yong Kang ◽  
Jennifer M. Kleinhenz ◽  
Tamara C. Murphy ◽  
C. Michael Hart
Keyword(s):  
Transcription Factors ◽  
Hypoxia Inducible Factor ◽  
Cell Counting ◽  
Mouse Lung ◽  
Therapeutic Effects ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Protein Levels

Peroxisome proliferator-activated receptor (PPAR) γ activation attenuates hypoxia-induced pulmonary hypertension (PH) in mice. The current study examined the hypothesis that PPARγ attenuates hypoxia-induced endothelin-1 (ET-1) signaling to mediate these therapeutic effects. To test this hypothesis, human pulmonary artery endothelial cells (HPAECs) were exposed to normoxia or hypoxia (1% O2) for 72 h and treated with or without the PPARγ ligand rosiglitazone (RSG, 10 μM) during the final 24 h of exposure. HPAEC proliferation was measured with MTT assays or cell counting, and mRNA and protein levels of ET-1 signaling components were determined. To explore the role of hypoxia-activated transcription factors, selected HPAECs were treated with inhibitors of hypoxia-inducible factor (HIF)-1α (chetomin) or nuclear factor (NF)-κB (caffeic acid phenethyl ester, CAPE). In parallel studies, male C57BL/6 mice were exposed to normoxia (21% O2) or hypoxia (10% O2) for 3 wk with or without gavage with RSG (10 mg·kg−1·day−1) for the final 10 days of exposure. Hypoxia increased ET-1, endothelin-converting enzyme-1, and endothelin receptor A and B levels in mouse lung and in HPAECs and increased HPAEC proliferation. Treatment with RSG attenuated hypoxia-induced activation of HIF-1α, NF-κB activation, and ET-1 signaling pathway components. Similarly, treatment with chetomin or CAPE prevented hypoxia-induced increases in HPAEC ET-1 mRNA and protein levels. These findings indicate that PPARγ activation attenuates a program of hypoxia-induced ET-1 signaling by inhibiting activation of hypoxia-responsive transcription factors. Targeting PPARγ represents a novel therapeutic strategy to inhibit enhanced ET-1 signaling in PH pathogenesis.

scholarly journals TRIM59 is Suppressed by Androgen Receptor and Acts to Promote Lineage Plasticity and Neuroendocrine Differentiation in Prostate Cancer

2021 ◽  
Author(s):  
Liancheng Fan ◽  
Yiming Gong ◽  
Yuman He ◽  
Wei-Qiang Gao ◽  
Baijun Dong ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Molecular Mechanisms ◽  
Neuroendocrine Differentiation ◽  
Tumor Model ◽  
Strongly Correlated ◽  
Neuroendocrine Prostate Cancer ◽  
In Vitro Effects

Abstract Background: The incidence of treatment-induced neuroendocrine prostate cancer (t-NEPC) has been greatly increasing after the usage of second-generation androgen receptor (AR) pathway inhibitors (ARPIs). Neuroendocrine differentiation (NED) is closely associated with ARPI treatment failure and poor prognosis in prostate cancer (PCa) patients. However, the molecular mechanisms of NED are not fully understood. Methods: TRIM59 expression was evaluated in PCa samples from patients at first diagnosis or at relapse stage post ARPI treatment by immunohistochemistry; in vitro effects of TRIM59 were determined by cell proliferation, sphere formation and cell migration assays; while in vivo analysis was performed using subcutaneous tumor model. Western blot, qPCR assay, dual luciferase assessment, chromatin immunoprecipitation and RNA sequencing were applied for mechanistic exploration.Results: Here we report that upregulation of TRIM59, a TRIM family protein, is strongly correlated with ARPI treatment mediated NED and shorter patient survival in PCas. AR binds to TRIM59 promoter and represses its transcription. ARPI treatment leads to a reversal of repressive epigenetic modifications on TRIM59 gene and the transcriptional restraint on TRIM59 by AR. Upregulated TRIM59 then drives the NED of PCa by enhancing the degradation of RB1 and P53 and upregulating downstream lineage plasticity-promoting transcription factor SOX2. Conclusion: Altogether, TRIM59 is negatively regulated by AR and acts as a key driver for NED in PCas. Our study provides a novel prognostic marker for PCas and shed new light on the molecular pathogenesis of t-NEPC, a deadly variant of PCa.

scholarly journals Huaier Extract Inhibits Prostate Cancer Growth via Targeting AR/AR-V7 Pathway

2021 ◽  
Vol 11 ◽  
Author(s):  
Zhengfang Liu ◽  
Cheng Liu ◽  
Keqiang Yan ◽  
Jikai Liu ◽  
Zhiqing Fang ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Nuclear Translocation ◽  
Mrna Levels ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant ◽  
Specific Protease ◽  
Hormone Sensitive

The androgen receptor (AR) plays a pivotal role in prostatic carcinogenesis, and it also affects the transition from hormone sensitive prostate cancer (HSPC) to castration-resistant prostate cancer (CRPC). Particularly, the persistent activation of the androgen receptor and the appearance of androgen receptor splicing variant 7 (AR-V7), could partly explain the failure of androgen deprivation therapy (ADT). In the present study, we reported that huaier extract, derived from officinal fungi, has potent antiproliferative effects in both HSPC and CRPC cells. Mechanistically, huaier extract downregulated both full length AR (AR-FL) and AR-V7 mRNA levels via targeting the SET and MYND domain-containing protein 3 (SMYD3) signaling pathway. Huaier extract also enhanced proteasome-mediated protein degradation of AR-FL and AR-V7 by downregulating proteasome-associated deubiquitinase ubiquitin-specific protease 14 (USP14). Furthermore, huaier extract inhibited AR-FL/AR-V7 transcriptional activity and their nuclear translocation. More importantly, our data demonstrated that huaier extract could re-sensitize enzalutamide-resistant prostate cancer cells to enzalutamide treatment in vitro and in vivo models. Our work revealed that huaier extract could be effective for treatment of prostate cancer either as monotherapy or in combination with enzalutamide.

Androgen-dependent regulation of Her-2/neu in prostate cancer cells

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 10099-10099
Author(s):  
R. Berger ◽  
D. I. Lin ◽  
M. Nieto ◽  
S. Signoretti ◽  
W. C. Hahn ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Cancer Cells ◽  
Cancer Cell Line ◽  
Prostate Cancer Cell Line ◽  
Prostate Cancer Cells ◽  
In Vivo Experiments ◽  
Her 2

10099 Background: The mechanisms underlying the progression of prostate cancer to androgen independence remain poorly understood. Overexpression of Her-2/neu (c-ErbB2) activates the androgen receptor pathway and confers a survival and growth advantage to prostate cancer cells in an androgen-deficient milieu. Methods: Androgen-sensitive prostate cancer cell line LNCaP was used as a model system in vitro and in vivo. Experiments in mice were undertaken by injecting cells orthotopically into the ventral lobe of the mice prostate. Results: Here, we report that androgen receptor (AR) and Her-2/neu reciprocally regulate each other in LNCaP human prostate cancer cells. Absence of androgens, AR blockade with Casodex (bicalutamide) or suppression of AR with RNAi induced Her-2/neu protein expression and phosphorylation in vitro and in vivo. Similarly, suppression of Her-2-neu expression resulted in AR upregulation. In contrast, upon re-administration of androgens, Her-2/neu mRNA, protein and phosphorylation levels decreased linearly with increasing concentrations of androgens as LNCaP cells re-entered the cell cycle. Conclusions: Thus, induction and activation of Her-2/neu occurs in an androgen-depleted environment or as a result of AR inactivation, promoting androgen-independent survival of prostate cancer cells. No significant financial relationships to disclose.

A novel peptide with a potential to enhance sorafenib’s therapeutic effects in hepatocellular carcinoma.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e13505-e13505
Author(s):  
Joline Sijing Lim ◽  
Todor Dimitrov ◽  
Kol Jia Yong ◽  
Chong Gao ◽  
Daniel G Tenen ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Stem Cell ◽  
Tumor Growth ◽  
Mechanism Of Action ◽  
Stem Cell Factor ◽  
Tumor Burden ◽  
Therapeutic Effects ◽  
Novel Approach

e13505 Background: Hepatocellular carcinoma (HCC) is the third leading cause of cancer related deaths worldwide, with chemotherapy or targeted therapy such as sorafenib achieving limited success. Recently stem cell factor SALL4 has emerged as a novel oncogene associated with leukemogenesis and is also implicated in many solid tumors. We have observed that SALL4 is not expressed in adult human liver tissues, but expressed in 30-40% of liver cancer, and this is associated with poorer prognosis and overall survival. We further tested whether inhibition of SALL4 function could be used for HCC treatment. Methods: A novel peptide blocking SALL4 function was designed and used to treat HCC lines with or without SALL4 expression. This is followed by evaluation for binding affinity, tumor growth inhibitory activity and mechanism of action. Treated cells were then transplanted in vivo into NOD/SCID mice and monitored for tumor growth. Comparison and/or combination of peptide with sorafenib were also carried out. Further modification of the peptide was done to allow for in vivo administration. Results: The peptide can effectively block SALL4 function. When used to treat HCC cell lines, it showed inhibitory effects in SNU398 cells (SALL4 expression), but not SNU387 cells (non-SALL4 expression). Post-xenotransplant, mice which received cells treated with peptide had slower rate of tumor growth (p=0.028) and lower tumor burden at dissection 26 days post transplant (p=0.048). Searching for its mechanism of action, we discovered that the peptide could affect the PTEN/AKT pathway, which was validated by western blot. When the peptide was combined with sorafenib, decreased cell viability was observed (p=0.03), suggestive of at least an additive effect between the peptide and sorafenib. Modification of peptide with TAT-protein showed similar inhibition of growth in vitro and was tested for further in-vivo usage through intraperitoneal injection. Conclusions: Our proof-of-principle studies have showed that a peptide blocking the function of stem cell factor SALL4 can be used as a novel approach for treating HCC. Combined with sorafenib, it may be able to enhance cell death and potentially lead to better outcomes in HCC patients.

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