Growth hormone (GH) receptors in prostate cancer: gene expression in human tissues and cell lines and characterization, GH signaling and androgen receptor regulation in LNCaP cells

Activins are multifunctional growth and differentiation factors and stimulate FSH-β gene expression and FSH secretion by the pituitary gonadotropes. Follistatins bind activin, resulting in the neutralization of activin bioactivity. The activin/follistatin system is present in the prostate tissue. Prostate-specific antigen (PSA) plays an important role in male reproductive physiology as well as being very important as a tumor marker for prostate cancer. Thus the regulation of PSA has important clinical implications. Previous studies showed that PSA is primarily regulated by androgens. In the present study, we evaluated the direct effects of activin A on the proliferation and PSA production of prostate cancer LNCaP cells, which express functional activin receptors and androgen receptor and PSA. LNCaP cells were treated with activin A and 5α-dihydrotestosterone (DHT) with or without their antagonists (follistatin or the nonsteroidal anti-androgen bicalutamide). Activin A decreased cell growth of LNCaP cells in a dose-dependent manner, whereas DHT increased it in a biphasic manner. In contrast to their opposing actions on cell growth, both activin A and DHT upregulated PSA gene expression and increased PSA secretion by LNCaP cells. The effects of activin A and DHT to increase PSA production were synergistic or additive. Follistatin or bicalutamide was without effect on cell growth or PSA production. The effects of activin A on LNCaP cells were blocked by follistatin, not by bicalutamide, whereas effects of DHT were prevented by bicalutamide, not by follistatin. Activin A upregulates PSA production, and the effect is through an androgen receptor-independent pathway. The activin/follistatin system can be a physiological modulator of PSA gene transcription and secretion in the prostate tissue, and activins may cooperate with androgen to upregulate PSA in vivo.

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The Immunophilin Ligands Cyclosporin A and FK506 Suppress Prostate Cancer Cell Growth by Androgen Receptor-Dependent and -Independent Mechanisms

Endocrinology ◽

10.1210/en.2007-0145 ◽

2007 ◽

Vol 148 (10) ◽

pp. 4716-4726 ◽

Cited By ~ 59

Author(s):

Sumudra Periyasamy ◽

Manya Warrier ◽

Manoranjani P. M. Tillekeratne ◽

Weinian Shou ◽

Edwin R. Sanchez

Keyword(s):

Prostate Cancer ◽

Androgen Receptor ◽

Cell Growth ◽

Cyclosporin A ◽

Cell Lines ◽

Cancer Cell ◽

Prostate Cancer Cell ◽

Lncap Cells ◽

Androgen Ablation ◽

Prostate Cells

The androgen receptor (AR) contributes to growth of prostate cancer even under conditions of androgen ablation. Thus, new strategies to target AR activity are needed. The AR interacts with the immunophilin FK506-binding protein 52 (FKBP52), and studies in the FKBP52 knockout mouse have shown that this protein is essential to AR activity in the prostate. Therefore, we tested whether the immunophilin ligand FK506 affected AR activity in prostate cancer cell lines. We also tested the hypothesis that the AR interacts with another immunophilin, cyclophilin 40 (Cyp40), and is regulated by its cognate ligand cyclosporin A (CsA). We show that levels of FKBP52, FKBP51, Cyp40, and a related co-chaperone PP5 were much higher in prostate cancer cells lines [(LNCaP), PC-3, and DU145] compared with primary prostate cells, and that the AR of LNCaP cells can interact with Cyp40. In the absence of androgen, CsA caused inhibition of cell growth in the AR-positive LNCaP and AR-negative PC-3 and DU145 cell lines. Interestingly, FK506 only inhibited LNCaP cells, suggesting a dependence on the AR for this effect. Both CsA and FK506 inhibited growth without inducing apoptosis. In LNCaP cells, CsA completely blocked androgen-stimulated growth, whereas FK506 was partially effective. Further studies in LNCaP cells revealed that CsA and FK506 were able to block or attenuate several stages of AR signaling, including hormone binding, nuclear translocation, and activity at several AR-responsive reporter and endogenous genes. These findings provide the first evidence that CsA and FK506 can negatively modulate proliferation of prostate cells in vitro. Immunophilins may now serve as new targets to disrupt AR-mediated prostate cancer growth.

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Androgen Receptor Regulation of Local Growth Hormone in Prostate Cancer Cells

Endocrinology ◽

10.1210/en.2016-1939 ◽

2017 ◽

Vol 158 (7) ◽

pp. 2255-2268 ◽

Cited By ~ 12

Author(s):

M. Victoria Recouvreux ◽

J. Boyang Wu ◽

Allen C. Gao ◽

Svetlana Zonis ◽

Vera Chesnokova ◽

...

Keyword(s):

Prostate Cancer ◽

Growth Hormone ◽

Androgen Receptor ◽

Cancer Cells ◽

Receptor Regulation ◽

Prostate Cancer Cells ◽

Local Growth

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Androgen receptor independent acquired mechanisms of resistance to enzalutamide in castration-resistant prostate cancer.

Journal of Clinical Oncology ◽

10.1200/jco.2014.32.4_suppl.129 ◽

2014 ◽

Vol 32 (4_suppl) ◽

pp. 129-129

Author(s):

Russell Zelig Szmulewitz ◽

Steve Kregel ◽

Masis Isikbay ◽

Yi Cai ◽

James Lin Chen ◽

...

Keyword(s):

Gene Expression ◽

Prostate Cancer ◽

Androgen Receptor ◽

Cell Lines ◽

Dna Sequences ◽

Castration Resistant Prostate Cancer ◽

Testosterone Levels ◽

Castration Resistant ◽

Stat Signaling

129 Background: Enzalutamide (MDV3100) is a second generation androgen receptor (AR) antagonist with potent activity in the treatment of castration resistant prostate cancer (CRPC). However, most patients develop resistance and progression of disease; thus there is a critical need to identify novel targetable pathways mechanistically linked to this resistance. Methods: A panel of four prostate cancer cell lines (LAPC-4, LNCaP, VCaP, and CWRR1) was created each with a different AR status that are resistant to MDV3100 by culturing cells long-term less than 6 months in the drug at pharmacologic levels. The MDV3100 resistant (MDV-R) lines were assayed for proliferation, viability, resistance to docetaxel, and tumor take of subcutaneous xenografts. AR expression and ligand binding domain (LBD) DNA sequences were analyzed. Gene expression microarray comparison of resistant and non-resistant parental cell lines was performed. Prostate-specific antigen (PSA) and testosterone levels were analyzed from conditioned media. Results: Cell lines demonstrated heterogeneous growth characteristics.In vivo studies depicted increased or unaltered tumor take and growth in castrate athymic mice. In some cell lines growth was increased in vitro when drug was withdrawn; yet this growth was inhibited by physiological testosterone levels, both in vitro and in vivo. MDV-R cells remained sensitive to docetaxel in vitro and had increased levels of ARmRNA. However, total AR protein levels were lower or unchanged than the parental lines, with evidence for increased truncated forms of AR. The AR LBD acquired no new mutations. Secreted PSA was lower in all but one MDV-R line. Gene expression analyses demonstrated strong upregulation of IGFBP3 in all MDV-R cells. Pathway analysis implicated increased IGF and JAK/STAT signaling whereas mammalian target of rapamycin (mTOR) signaling was decreased. Conclusions: Although AR-mediated pathways contribute to enzalutamide resistance, a broader approach across several cell lines suggests that there may be even a greater contribution from pleiotropic, non-AR mediated mechanisms. Such mechanisms may include IGF signaling, JAK/STAT signaling and modulation of mTOR.

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The significance of Her2 on androgen receptor protein stability in the transition of androgen requirement in prostate cancer cells

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00610.2010 ◽

2011 ◽

Vol 300 (5) ◽

pp. E902-E908 ◽

Cited By ~ 12

Author(s):

Fu-Ning Hsu ◽

Min-Shiou Yang ◽

Eugene Lin ◽

Chun-Fu Tseng ◽

Ho Lin

Keyword(s):

Prostate Cancer ◽

Cell Cycle ◽

Androgen Receptor ◽

Protein Stability ◽

Cancer Cells ◽

Cell Lines ◽

Lncap Cells ◽

Prostate Cancer Cells ◽

Androgen Ablation ◽

Androgen Independent

Androgen ablation therapy is the most common strategy for suppressing prostate cancer progression; however, tumor cells eventually escape androgen dependence and progress to an androgen-independent phase. The androgen receptor (AR) plays a pivotal role in this transition. To address this transition mystery in prostate cancer, we established an androgen-independent prostate cancer cell line (LNCaPdcc), by long-term screening of LNCaP cells in androgen-deprived conditions, to investigate changes of molecular mechanisms before and after androgen withdrawal. We found that LNCaPdcc cells displayed a neuroendocrine morphology, less aggressive growth, and lower expression levels of cell cycle-related factors, although the cell cycle distribution was similar to parental LNCaP cells. Notably, higher protein expression of AR, phospho-Ser81-AR, and PSA in LNCaPdcc cells were observed. The nuclear distribution and protein stability of AR increased in LNCaPdcc cells. In addition, cell proliferation results exhibited the biphasic nature of the androgen (R1881) effect in two cell lines. On the other hand, LNCaPdcc cells expressed higher levels of Her2, phospho-Tyr1221/1222-Her2, ErbB3, and ErbB4 proteins than parental LNCaP cells. These two cell lines exhibited distinct responses to Her2 activation (by heregulin treatment) on Her2 phosphorylation and Her2 inhibition (by AG825 or Herceptin treatments) on proliferation. In addition, the Her2 inhibitor more effectively caused AR degradation and diminished AR Ser81 phosphorylation in LNCaPdcc cells. Taken together, our data demonstrate that Her2 plays an important role in the support of AR protein stability in the transition of androgen requirement in prostate cancer cells. We hope these findings will provide novel insight into the treatment of hormone-refractory prostate cancer.

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Androgen Receptor Controls EGFR and ERBB2 Gene Expression at Different Levels in Prostate Cancer Cell Lines

Cancer Research ◽

10.1158/0008-5472.can-08-3760 ◽

2009 ◽

Vol 69 (7) ◽

pp. 2941-2949 ◽

Cited By ~ 46

Author(s):

Jean-Christophe Pignon ◽

Benjamin Koopmansch ◽

Gregory Nolens ◽

Laurence Delacroix ◽

David Waltregny ◽

...

Keyword(s):

Gene Expression ◽

Prostate Cancer ◽

Androgen Receptor ◽

Cell Lines ◽

Cancer Cell ◽

Prostate Cancer Cell ◽

Cancer Cell Lines ◽

Prostate Cancer Cell Lines ◽

Erbb2 Gene ◽

Different Levels

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Design, Synthesis and Evaluation of Novel Substituted (5-methyl-1H-pyrazol-3-yl)- 1,3,4-oxadiazole as Potent Androgen Receptor Antagonist

Anti-Cancer Agents in Medicinal Chemistry ◽

10.2174/1871520619666191121095720 ◽

2020 ◽

Vol 20 (1) ◽

pp. 84-93

Author(s):

Sasikumar Andavar ◽

Mohanasrinivasan Vaithilingam ◽

Divakar Selvaraj ◽

Ajeeshkumar A. Kumaran ◽

Krishnaswamy Devanathan

Keyword(s):

Gene Expression ◽

Prostate Cancer ◽

Androgen Receptor ◽

Drug Design ◽

Point Mutation ◽

Cell Lines ◽

1H Nmr ◽

13C Nmr ◽

Docking Studies ◽

Rational Drug Design

Background: Androgen Receptor (AR) is one of the highly explored targets for the treatment of prostate cancer. The emergence of point mutation in the Ligand Binding Domain (LBD) of AR has resulted in the development of resistance against AR antagonist. The point mutation T877A, W741L and F876L confer resistance to flutamide, bicalutamide and enzalutamide respectively. There is no AR antagonist in the present clinical set up without resistance. Hence, our aim in this study is to design a novel molecule to overcome the resistance caused by point mutation. Methods: Here, we developed novel AR antagonist bearing (5-methyl-1H-pyrazol-3-yl)-1, 3,4-oxadiazole core by rational drug design. The test molecules 8a-h were synthesized from the corresponding dihydrazide compounds 7a-h on treatment with phosphorous oxychloride on reflux conditions. The structure of the molecules was confirmed from spectral data such as IR, 1H-NMR, HRMS and 13C-NMR. The synthesized compounds were screened for cytotoxicity in prostate cancer cell lines LNCaP-FGC and PC3. The confirmation of AR mediated activity of the test compounds was confirmed by gene expression study. The interaction of the best active ligands with mutant AR was predicted and drug design was rationalized through docking studies. Results: The test compounds 8a-h were synthesized and the structures were conformed using suitable techniques like IR, 1H-NMR, HRMS and 13C-NMR. Among the tested compounds, 8b and 8d showed potent antiproliferative activity against mutant AR cell lines. Further, these compounds significantly decreased the gene expression of prostate cancer biomarkers. Conclusion: In this study, we have identified a potential hit molecule for AR antagonism that could be further developed to obtain a potent clinical candidate.

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Regulation of IKKe expression by androgen receptor and NF-kB transcriptional factor in prostate cancer

Journal of Clinical Oncology ◽

10.1200/jco.2006.24.18_suppl.10106 ◽

2006 ◽

Vol 24 (18_suppl) ◽

pp. 10106-10106

Author(s):

B. Péant ◽

J. Diallo ◽

L. Lessard ◽

A. Mes-Masson ◽

F. Saad

Keyword(s):

Prostate Cancer ◽

Androgen Receptor ◽

Cell Lines ◽

Nuclear Translocation ◽

Dominant Negative ◽

Lncap Cells ◽

Dominant Negative Form ◽

Androgen Resistance ◽

Dependent Cell ◽

Hormone Refractory

10106 Background: In unstimulated cells, NF-kB transcription factor is sequestered in the cytoplasm as an inactive p65/p50 dimer through interaction with a member of the inhibitor of kB protein family (IkBa). Prominent constitutive activation of NF-kB was observed in prostate cancer (PCa) cell lines lacking androgen receptor (AR) expression (PC3 and DU145) whereas only very low levels of NF-kB activity were seen in androgen-dependent cell lines (LNCaP and CWR22Rv1). As IkB kinase-e (IKKe) has recently been shown to be controlled by NF-kB, we hypothesize that IKKe may be involved in PCa progression based on its interaction with the NF-kB protein, and that these interactions are influenced by AR signaling. Methods: LNCaP cells were used to study IKKe expression with or without stimulation by the analog of androgen R1881 and by the tumor necrosis factor (TNF)-a. IKKe protein and RNA expression were characterized by immunoblot assay and quantitative PCR, respectively. IKKe expression was then correlated with p65 nuclear localisation. NF-kB activity was inhibited using an IkBa dominant negative construction. Inhibition of AR synthesis was performed using a siRNA against AR. Results: IKKe gene expression was stimulated by TNF-a treatment in LNCaP cells and inhibited by transfection of a dominant negative form of IkBa which prevented the nuclear translocation of p65. We also observed constitutive IKKe expression in hormone-refractory cells. Furthermore, we showed that TNF-a-induced IKKe expression is inhibited by R1881 in hormone-responsive PCa cells and this inhibition was correlated with the modulation of IkBa expression by R1881. Finally, we observed that the expression of IKKe is constitutively induced after blocking AR expression in LNCaP cells. Conclusions:. Our results show that IKKe expression is regulated by NF-kB in PCa cell lines. Moreover, IKKe appears to be down-regulated by ligand-dependent AR signaling through the control of IkBa expression. Further studies will be needed in order to determine the implications of this phenomenon with regard to NF-kB regulation, androgen resistance and effect on PCa progression. No significant financial relationships to disclose.

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