scholarly journals PXD101 potentiates hormonal therapy and prevents the onset of castration-resistant phenotype modulating androgen receptor, HSP90, and CRM1 in preclinical models of prostate cancer

2013 ◽  
Vol 20 (3) ◽  
pp. 321-337 ◽  
Author(s):  
Giovanni Luca Gravina ◽  
Francesco Marampon ◽  
Paola Muzi ◽  
Andrea Mancini ◽  
Margherita Piccolella ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Hormonal Therapy ◽  
Disease Stage ◽  
Castration Resistant ◽  
Resistant Phenotype ◽  
Expression Activity ◽  
Gsk 3Β ◽  
Functional Knockdown ◽  
Expression And Activity

Aberrant activation or ‘reactivation’ of androgen receptor (AR) during androgen ablation therapy shows a potential cause for the development of castration-resistant prostate cancer. This study tested the hypothesis that PXD101, a potent pan histone deacetylase (HDAC) inhibitor, may prevent onset of castration-resistant phenotype and potentiate hormonal therapy. A panel of human prostate cancer cells with graded castration-resistant phenotype and in vivo models were used to verify this hypothesis. In this report, we demonstrated that hormonal manipulation favors the onset of castration-resistant phenotype increasing HDAC expression and activity as well as modulating expression and activity of AR, EGFR, HER2, and Akt. Consistent with these observations, the functional knockdown of HDACs by PXD101 prevented the onset of castration-resistant phenotype with a significant downregulation of AR, EGFR, HER2, and Akt expression/activity. The dysregulation of functional cooperation between HDAC6 with hsp90, on the one hand, and between GSK-3β with CRM1, on the other hand, may explain the biological effects of PXD101. In this regard, the HDAC6 silencing or the functional knockdown of hsp90 by 17AAG resulted in the selective downregulation of AR, EGFR, HER2, and Akt expression/activity, while the decreased phosphorylation of GSK-3β mediated by PXD101 increased the nuclear expression of CRM1, which in turn modified the AR and survivin recycling with increased caspase 3 activity. HDAC inhibitors retain the ability to prevent the onset of castration-resistant phenotype and, therefore, merit clinical investigation in this setting. However, additional data are needed to develop clinical treatment strategies for this disease stage.

scholarly journals Hormonal Therapy Promotes Hormone-Resistant Phenotype by Increasing DNMT Activity and Expression in Prostate Cancer Models

Endocrinology ◽  
2011 ◽  
Vol 152 (12) ◽  
pp. 4550-4561 ◽  
Author(s):  
Giovanni Luca Gravina ◽  
Francesco Marampon ◽  
Margherita Piccolella ◽  
Marcella Motta ◽  
Luca Ventura ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Hormonal Therapy ◽  
Standard Condition ◽  
Human Prostate ◽  
Human Prostate Cancer ◽  
In Vivo Models ◽  
Resistant Phenotype ◽  
Expression And Activity

We hypothesized that hormonal therapy favors the development of the hormone-resistant phenotype through epigenetic mechanisms. Human prostate cancer tissues and in vitro and in vivo models were used to verify this hypothesis. We demonstrated that tumor cells continuously treated with bicalutamide (BCLT) or cultured in androgen-depleted medium progressively acquire higher DNA methyltransferase (DNMT) activity and expression than cells cultured in standard condition. Increased DNMT expression and activity also paralleled the up-regulation of truncated AR isoforms, which favors the development of the hormone-resistant phenotype. After androgen stimulation with 10−12m dihydrotestosterone, DNMT activity was significantly reduced in comparison with hormonal therapy. Consistent with these observations, the silencing of DNMT3a and DNMT3b significantly decreased the DNMT activity levels. These findings were also directly correlated with phosphatase and tensin homolog down-regulation and activation of ERK and phosphatidylinositol 3-kinases/AKT8 virus oncogene cellular homolog pathways. The use of a pan-DNMT inhibitor (5-Azacitidine) greatly reduced the development of the hormone-resistant phenotype induced by long-term BCLT treatment, and this finding correlated with low DNMT activity. The regulation of DNMT activity was, in some measure, dependent on the androgen receptor, as small interfering RNA treatment targeting the androgen receptor greatly decreased the modulation of DNMT activity under androgenic and antiandrogenic stimulation. These observations were correlated in vivo in patients, as demonstrated by immunohistochemistry. Patients treated by BCLT before surgery had higher DNMT3a and DNMT3b expression than patients who had not undergone this treatment. Our findings provide evidence of a relationship between the castration-resistant phenotype and DNMT expression and activity in human prostate cancer.

Combination Therapies Using Metformin and/or Valproic Acid in Prostate Cancer: Possible Mechanistic Interactions

2019 ◽  
Vol 19 (5) ◽  
pp. 368-381 ◽  
Author(s):  
Linh N.K. Tran ◽  
Ganessan Kichenadasse ◽  
Pamela J. Sykes
Keyword(s):  
Prostate Cancer ◽  
Valproic Acid ◽  
Androgen Receptor ◽  
Gene Fusion ◽  
Combination Therapies ◽  
Slowing Down ◽  
Castration Resistant ◽  
Local Pca ◽  
End Stage ◽  
Fusion Products

Prostate cancer (PCa) is the most frequent cancer in men. The evolution from local PCa to castration-resistant PCa, an end-stage of disease, is often associated with changes in genes such as p53, androgen receptor, PTEN, and ETS gene fusion products. Evidence is accumulating that repurposing of metformin (MET) and valproic acid (VPA) either when used alone, or in combination, with another therapy, could potentially play a role in slowing down PCa progression. This review provides an overview of the application of MET and VPA, both alone and in combination with other drugs for PCa treatment, correlates the responses to these drugs with common molecular changes in PCa, and then describes the potential for combined MET and VPA as a systemic therapy for prostate cancer, based on potential interacting mechanisms.

scholarly journals Interplay Between SOX9, Wnt/β-Catenin and Androgen Receptor Signaling in Castration-Resistant Prostate Cancer

2019 ◽  
Vol 20 (9) ◽  
pp. 2066 ◽  
Author(s):  
Namrata Khurana ◽  
Suresh C. Sikka
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Signaling Pathways ◽  
Critical Role ◽  
Castration Resistant Prostate Cancer ◽  
Form Complex ◽  
Androgen Receptor Signaling ◽  
Castration Resistant ◽  
Signaling Axis

Androgen receptor (AR) signaling plays a key role not only in the initiation of prostate cancer (PCa) but also in its transition to aggressive and invasive castration-resistant prostate cancer (CRPC). However, the crosstalk of AR with other signaling pathways contributes significantly to the emergence and growth of CRPC. Wnt/β-catenin signaling facilitates ductal morphogenesis in fetal prostate and its anomalous expression has been linked with PCa. β-catenin has also been reported to form complex with AR and thus augment AR signaling in PCa. The transcription factor SOX9 has been shown to be the driving force of aggressive and invasive PCa cells and regulate AR expression in PCa cells. Furthermore, SOX9 has also been shown to propel PCa by the reactivation of Wnt/β-catenin signaling. In this review, we discuss the critical role of SOX9/AR/Wnt/β-catenin signaling axis in the development and progression of CRPC. The phytochemicals like sulforaphane and curcumin that can concurrently target SOX9, AR and Wnt/β-catenin signaling pathways in PCa may thus be beneficial in the chemoprevention of PCa.

scholarly journals Androgen receptor mutations in patients with castration-resistant prostate cancer treated with apalutamide

2017 ◽  
Vol 28 (9) ◽  
pp. 2264-2271 ◽  
Author(s):  
D.E. Rathkopf ◽  
M.R. Smith ◽  
C.J. Ryan ◽  
W.R. Berry ◽  
N.D. Shore ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant

scholarly journals Development of an Androgen Receptor Inhibitor Targeting the N-Terminal Domain of Androgen Receptor for Treatment of Castration Resistant Prostate Cancer

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3488
Author(s):  
Fuqiang Ban ◽  
Eric Leblanc ◽  
Ayse Derya Cavga ◽  
Chia-Chi Flora Huang ◽  
Mark R. Flory ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Splice Variants ◽  
Full Length ◽  
Cancer Resistance ◽  
Castration Resistant Prostate Cancer ◽  
Terminal Domain ◽  
Castration Resistant ◽  
Coregulatory Proteins ◽  
Androgen Binding

Prostate cancer patients undergoing androgen deprivation therapy almost invariably develop castration-resistant prostate cancer. Resistance can occur when mutations in the androgen receptor (AR) render anti-androgen drugs ineffective or through the expression of constitutively active splice variants lacking the androgen binding domain entirely (e.g., ARV7). In this study, we are reporting the discovery of a novel AR-NTD covalent inhibitor 1-chloro-3-[(5-([(2S)-3-chloro-2-hydroxypropyl]amino)naphthalen-1-yl)amino]propan-2-ol (VPC-220010) targeting the AR-N-terminal Domain (AR-NTD). VPC-220010 inhibits AR-mediated transcription of full length and truncated variant ARV7, downregulates AR response genes, and selectively reduces the growth of both full-length AR- and truncated AR-dependent prostate cancer cell lines. We show that VPC-220010 disrupts interactions between AR and known coactivators and coregulatory proteins, such as CHD4, FOXA1, ZMIZ1, and several SWI/SNF complex proteins. Taken together, our data suggest that VPC-220010 is a promising small molecule that can be further optimized into effective AR-NTD inhibitor for the treatment of CRPC.

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