scholarly journals Mechanisms of Androgen Receptor Agonist- and Antagonist-Mediated Cellular Senescence in Prostate Cancer

Cancers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1833 ◽  
Author(s):  
Miriam Kokal ◽  
Kimia Mirzakhani ◽  
Thanakorn Pungsrinont ◽  
Aria Baniahmad
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Cellular Senescence ◽  
Cellular Response ◽  
Cell Cycle Progression ◽  
Current Knowledge ◽  
Ex Vivo ◽  
Cell Senescence ◽  
Dependent Manner ◽  
Androgen Levels

The androgen receptor (AR) plays a leading role in the control of prostate cancer (PCa) growth. Interestingly, structurally different AR antagonists with distinct mechanisms of antagonism induce cell senescence, a mechanism that inhibits cell cycle progression, and thus seems to be a key cellular response for the treatment of PCa. Surprisingly, while physiological levels of androgens promote growth, supraphysiological androgen levels (SAL) inhibit PCa growth in an AR-dependent manner by inducing cell senescence in cancer cells. Thus, oppositional acting ligands, AR antagonists, and agonists are able to induce cellular senescence in PCa cells, as shown in cell culture model as well as ex vivo in patient tumor samples. This suggests a dual AR-signaling dependent on androgen levels that leads to the paradox of the rational to keep the AR constantly inactivated in order to treat PCa. These observations however opened the option to treat PCa patients with AR antagonists and/or with androgens at supraphysiological levels. The latter is currently used in clinical trials in so-called bipolar androgen therapy (BAT). Notably, cellular senescence is induced by AR antagonists or agonist in both androgen-dependent and castration-resistant PCa (CRPC). Pathway analysis suggests a crosstalk between AR and the non-receptor tyrosine kinase Src-Akt/PKB and the PI3K-mTOR-autophagy signaling in mediating AR-induced cellular senescence in PCa. In this review, we summarize the current knowledge of therapeutic induction and intracellular pathways of AR-mediated cellular senescence.

scholarly journals The androgen receptor—lncRNASAT1-AKT-p15 axis mediates androgen-induced cellular senescence in prostate cancer cells

Oncogene ◽  
2021 ◽  
Author(s):  
Kimia Mirzakhani ◽  
Julia Kallenbach ◽  
Seyed Mohammad Mahdi Rasa ◽  
Federico Ribaudo ◽  
Martin Ungelenk ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Cellular Senescence ◽  
Laser Scanning ◽  
Ex Vivo ◽  
Treated Patient ◽  
Cell Senescence ◽  
Laser Scanning Microscopy ◽  
Akt Inhibitor ◽  
Signaling Axis

AbstractThe bipolar androgen therapy (BAT) to treat prostate cancer (PCa) includes cycles of supraphysiological androgen levels (SAL) under androgen-deprivation therapy (ADT). We showed previously that SAL induces cellular senescence in androgen-sensitive PCa cells and in ex vivo-treated patient PCa tumor samples. Here, we analyzed the underlying molecular pathway and reveal that SAL induces cellular senescence in both, castration-sensitive (CSPC) LNCaP and castration-resistant PCa (CRPC) C4-2 cells through the cell cycle inhibitor p15INK4b and increased phosphorylation of AKT. Treatment with the AKT inhibitor (AKTi) potently inhibited SAL-induced expression of p15INK4b and cellular senescence in both cell lines. Proximity-ligation assays (PLA) combined with high-resolution laser-scanning microscopy indicate that SAL promotes interaction of endogenous androgen receptor (AR) with AKT in the cytoplasm as well as in the nucleus detectable after three days. Transcriptome sequencing (RNA-seq) comparing the SAL-induced transcriptomes of LNCaP with C4-2 cells as well as with AKTi-treated cell transcriptomes revealed landscapes for cell senescence. Interestingly, one of the identified genes is the lncRNASAT1. SAL treatment of native patient tumor samples ex vivo upregulates lncRNASAT1. In PCa tumor tissues, lncRNASAT1 is downregulated compared with nontumor tissues of the same patients. Knockdown indicates that the lncRNASAT1 is crucial for SAL-induced cancer-cell senescence as an upstream factor for pAKT and for p15INK4b. Further, knockdown of lncRNASAT1 enhances cell proliferation by SAL, suggesting that lncRNASAT1 serves as a tumor suppressor at SAL. Interestingly, immunoprecipitation of AR detected lncRNASAT1 as an AR-interacting partner that regulates AR target-gene expression. Similarly, RNA-ChIP experiments revealed the interaction of AR with lncRNASAT1 on chromatin. Thus, we identified a novel AR-lncRNASAT1-AKT-p15INK4b signaling axis to mediate SAL-induced cellular senescence.

scholarly journals Antithetic hTERT Regulation by Androgens in Prostate Cancer Cells: hTERT Inhibition Is Mediated by the ING1 and ING2 Tumor Suppressors

Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 4025
Author(s):  
Sophie Bartsch ◽  
Kimia Mirzakhani ◽  
Laura Neubert ◽  
Alexander Stenzel ◽  
Marzieh Ehsani ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Tumor Suppressors ◽  
Ex Vivo ◽  
Core Promoter ◽  
Dependent Manner ◽  
Htert Expression ◽  
Concentration Dependent Manner ◽  
Human Telomerase ◽  
Cancer Spheroids ◽  
Androgen Levels

The human telomerase is a key factor during tumorigenesis in prostate cancer (PCa). The androgen receptor (AR) is a key drug target controlling PCa growth and regulates hTERT expression, but is described to either inhibit or to activate. Here, we reveal that androgens repress and activate hTERT expression in a concentration-dependent manner. Physiological low androgen levels activate, while, notably, supraphysiological androgen levels (SAL), used in bipolar androgen therapy (BAT), repress hTERT expression. We confirmed the SAL-mediated gene repression of hTERT in PCa cell lines, native human PCa samples derived from patients treated ex vivo, as well as in cancer spheroids derived from androgen-dependent or castration resistant PCa (CRPC) cells. Interestingly, chromatin immuno-precipitation (ChIP) combined with functional assays revealed a positive (pARE) and a negative androgen response element (nARE). The nARE was narrowed down to 63 bp in the hTERT core promoter region. ARs and tumor suppressors, inhibitors of growths 1 and 2 (ING1 and ING2, respectively), are androgen-dependently recruited. Mechanistically, knockdown indicates that ING1 and ING2 mediate AR-regulated transrepression. Thus, our data suggest an oppositional, biphasic function of AR to control the hTERT expression, while the inhibition of hTERT by androgens is mediated by the AR co-repressors ING1 and ING2.

scholarly journals A Natural Androgen Receptor Antagonist Induces Cellular Senescence in Prostate Cancer Cells

2014 ◽  
Vol 28 (11) ◽  
pp. 1831-1840 ◽  
Author(s):  
Wiebke Hessenkemper ◽  
Julia Roediger ◽  
Sophie Bartsch ◽  
Adriaan B. Houtsmuller ◽  
Martin E. van Royen ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Tyrosine Kinase ◽  
Cellular Senescence ◽  
Nuclear Translocation ◽  
Ex Vivo ◽  
Specific Antigen ◽  
Tissue Samples ◽  
Interaction Partners ◽  
P16 Expression

We have previously identified a natural occurring, androgen receptor-specific antagonist. Atraric acid (AA) inhibits the transactivation of the androgen receptor (AR) and androgen-mediated growth of AR-expressing human prostate cancer (PCa) cell lines. Here we show that AA treatment of living cells provokes molecular changes of AR signaling. In addition to a deceleration of nuclear translocation a block of the intramolecular amino/carboxy (N/C)-terminal interaction of the AR was observed. Furthermore, using high-resolution confocal fluorescence microscopy, a reduced speckle formation of the AR was observed in line with an increased intranuclear mobility of the receptor. This suggests decreased DNA binding of the AR, which is further indicated by an impaired chromatin recruitment of the AR to the prostate-specific antigen promoter and enhancer shown by chromatin immunoprecipitation experiments. Using inhibitors of the non-receptor tyrosine kinase Src or Akt, known interaction partners of AR, reduced the level of androgen-induced cellular senescence suggesting a partly non-genomic pathway to induce cellular senescence by AA. Using PP2 (4-Amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine) pyrimidine or Akt inhibitors, inhibitors of the nonreceptor tyrosine kinase Src or Akt, known interaction partners of AR, reduced the level of androgen-induced cellular senescence, suggesting a partly nongenomic pathway to induce cellular senescence by AA. Treatment of LNCaP cells with AA is associated with hypophosphorylation of the retinoblastoma tumor suppressor and an increase of p16 expression, whereas the p53-p21 signaling pathway seems not be affected by AA treatment. Analyzing human PCa tissue samples treated with AA ex vivo also indicates an induction of cellular senescence associated with an increase of p16 expression but not p21. Taken together, these data indicate that AA exhibits novel features to inhibit AR amino/carboxy-terminal interaction, the AR-mediated nuclear activities and growth of PCa cells.

scholarly journals Dendranthema zawadskii var. lucidum (Nakai) J.H. Park Extract Inhibits Cellular Senescence in Human Dermal Fibroblasts and Aging-Related Inflammation in Rats

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 801
Author(s):  
Jehun Choi ◽  
Gwi-Yeong Jang ◽  
Jeonghoon Lee ◽  
Hae-Young Chung ◽  
Hyung-Jun Noh ◽  
...  
Keyword(s):  
Cellular Senescence ◽  
Cell Cycle Progression ◽  
Inflammatory Responses ◽  
Dermal Fibroblast ◽  
Dermal Fibroblasts ◽  
Dependent Manner ◽  
Aged Rats ◽  
Age Related ◽  
Dendranthema Zawadskii ◽  
Beta Galactosidase

Senescence is the phenomenon by which physiological functions of organisms degenerate with time. Cellular senescence is marked by an inhibition of cell cycle progression. Beta-galactosidase accumulates in the lysosomes of aged cells. In this study, human dermal fibroblast cells (HDFs) were treated with 0.5 μM doxorubicin for 4 h to induce cellular senescence. Senescence-associated beta-galactosidase (SA-β-gal) activity was then measured 72 h after treatment with aerial parts of Dendranthema zawadskii var. lucidum (Nakai) J.H. Park (DZ) extract. Treatment with DZ extract significantly decreased SA-β-gal activity in a dose-dependent manner in HDFs. Additionally, DZ extract treatment reduced age-related oxidative stress and inflammation in the aortas of aged rats. The reactive oxygen species (ROS) levels in aortas of aged control rats were higher than those in young rats. However, DZ extract-fed aged rats showed significantly lower ROS levels than the aged control rats. When the aged rats were treated with DZ extract at either 0.2 or 1.0 mg∙kg−1∙day−1, NF-κB levels in aorta tissue decreased significantly compared to those in aorta tissue of the aged control rats without DZ treatment. In addition, DZ extract-fed aged rat aortas showed significant reductions in expression of iNOS and COX-2 induced by NF-κB translocation. Therefore, these results suggest that DZ effectively inhibited senescence-related NF-κB activation and inflammation. DZ extract may have a role in the prevention of the vascular inflammatory responses that occur during vascular aging.

scholarly journals In vitro model systems to study androgen receptor signaling in prostate cancer

2013 ◽  
Vol 20 (2) ◽  
pp. R49-R64 ◽  
Author(s):  
Natalie Sampson ◽  
Hannes Neuwirt ◽  
Martin Puhr ◽  
Helmut Klocker ◽  
Iris E Eder
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Cellular Response ◽  
Three Dimensional ◽  
Model Systems ◽  
Transfer Of Knowledge ◽  
Prostate Epithelial Cells ◽  
Technological Advances ◽  
Culture Models

Prostate cancer (PCa) is one of the most common causes of male cancer-related death in Western nations. The cellular response to androgens is mediated via the androgen receptor (AR), a ligand-inducible transcription factor whose dysregulation plays a key role during PCa development and progression following androgen deprivation therapy, the current mainstay systemic treatment for advanced PCa. Thus, a better understanding of AR signaling and new strategies to abrogate AR activity are essential for improved therapeutic intervention. Consequently, a large number of experimental cell culture models have been established to facilitate in vitro investigations into the role of AR signaling in PCa development and progression. These different model systems mimic distinct stages of this heterogeneous disease and exhibit differences with respect to AR expression/status and androgen responsiveness. Technological advances have facilitated the development of in vitro systems that more closely reflect the physiological setting, for example via the use of three-dimensional coculture to study the interaction of prostate epithelial cells with the stroma, endothelium, immune system and tissue matrix environment. This review provides an overview of the most commonly used in vitro cell models currently available to study AR signaling with particular focus on their use in addressing key questions relating to the development and progression of PCa. It is hoped that the continued development of in vitro models will provide more biologically relevant platforms for mechanistic studies, drug discovery and design ensuring a more rapid transfer of knowledge from the laboratory to the clinic.

scholarly journals Expression and Function of Lysophosphatidic Acid LPA1 Receptor in Prostate Cancer Cells

Endocrinology ◽  
2006 ◽  
Vol 147 (10) ◽  
pp. 4883-4892 ◽  
Author(s):  
Rishu Guo ◽  
Elizabeth A. Kasbohm ◽  
Puneeta Arora ◽  
Christopher J. Sample ◽  
Babak Baban ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cell Proliferation ◽  
Androgen Receptor ◽  
Cancer Cells ◽  
Lysophosphatidic Acid ◽  
Cell Cycle Progression ◽  
Receptor Activation ◽  
Lncap Cells ◽  
Prostate Cancer Cells ◽  
And Migration

The bioactive phospholipid lysophosphatidic acid (LPA) promotes cell proliferation, survival, and migration by acting on cognate G protein-coupled receptors named LPA1, LPA2, and LPA3. We profiled gene expression of LPA receptors in androgen-dependent and androgen-insensitive prostate cancer cells and found that LPA1 gene is differentially expressed in androgen-insensitive and LPA-responsive but not androgen-dependent and LPA-resistant cells. In human prostate specimens, expression of LPA1 gene was significantly higher in the cancer compared with the benign tissues. The androgen-dependent LNCaP cells do not express LPA1 and do not proliferate in response to LPA stimulation, implying LPA1 transduces cell growth signals. Accordingly, stable expression of LPA1 in LNCaP cells rendered them responsive to LPA-induced cell proliferation and decreased their doubling time in serum. Implantation of LNCaP-LPA1 cells resulted in increased rate of tumor growth in animals compared with those tumors that developed from the wild-type cells. Growth of LNCaP cells depends on androgen receptor activation, and we show that LPA1 transduces Gαi-dependent signals to promote nuclear localization of androgen receptor and cell proliferation. In addition, treatment with bicalutamide inhibited LPA-induced cell cycle progression and proliferation of LNCaP-LPA1 cells. These results suggest the possible utility of LPA1 as a drug target to interfere with progression of prostate cancer.

A randomized, open-label, phase II study of MDV3100 alone or in combination with leuprolide and dutasteride as neoadjuvant therapy to prostatectomy in intermediate and high-risk prostate cancer.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. TPS4695-TPS4695 ◽  
Author(s):  
Robert B. Montgomery ◽  
Anthony Joshua ◽  
Alison L. Hannah ◽  
Amy C. Peterson ◽  
Christian Lopez ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Radical Prostatectomy ◽  
Cancer Survival ◽  
Nuclear Translocation ◽  
Systemic Disease ◽  
Complete Response ◽  
Open Label ◽  
Androgen Levels

TPS4695 Background: MDV3100 is a potent androgen receptor (AR) signaling inhibitor (ARSI) that inhibits AR signaling via three mechanisms: inhibition of androgen binding to AR, inhibition of AR nuclear translocation, and inhibition of nuclear AR-DNA binding. In vivo, MDV3100 induces significant prostate cancer apoptosis, an effect not seen with anti-androgens. To date, the use of neoadjuvant androgen deprivation therapy has not led to an improvement in time to PSA progression (Soloway 2002; Aus 2002). While serum androgens may be suppressed using luteinizing hormone-releasing hormone agonists, intratumoral levels of androgens remain, driving continued AR signaling and prostate cancer survival. More effective inhibition of AR signaling may improve local and systemic disease control. Methods: MDV3100-07 will assess the effect of 6 mos of neoadjuvant AR blockade with AR inhibition alone (MDV3100) or in combination with maximal suppression of androgens (MDV3100 +leuprolide [L] + dutasteride [D]). Eligible patients will have treatment-naive localized prostate cancer and be candidates for radical prostatectomy. Patients must have either PSA > 10 ng/mL or Gleason score ≥ 7 (4 + 3) with ≥3 cores containing tumor. Patients with evidence of metastatic/nodal disease are excluded. All patients receive MDV3100 (160 mg/d PO); those randomized to MDV3100+L+D therapy also receive L (22.5mg IM q3m) and D (0.5 mg/day PO). Serum/tumor androgen levels will be serially assessed. Tissue from the diagnostic and prostatectomy specimens will be evaluated for androgen levels, AR signaling profiles, and selected markers of apoptosis and mitotic indices. The primary efficacy endpoint is pathological complete response (pCR) rate at time of radical prostatectomy. For each arm, the percent of patients who achieve a pCR will be compared to the percent pCR in patients treated with neoadjuvant leuprolide, estimated to be 5% in a mixed low-to-intermediate risk population. Target Accrual: 40 pts will be randomized 1:1 to MDV3100 or MDV3100+L+D therapy. Keywords:MDV3100, prostate cancer, androgen receptor, anti-androgen, Phase 2, neoadjuvant.

scholarly journals Cell Cycle Modulation of CHO-K1 Cells Under Genistein Treatment Correlates with Cells Senescence, Apoptosis and ROS Level but in a Dose-Dependent Manner

2019 ◽  
Vol 9 (3) ◽  
pp. 453-461
Author(s):  
Riris Istighfari Jenie ◽  
Nur Dina Amalina ◽  
Gagas Pradani Nur Ilmawati ◽  
Rohmad Yudi Utomo ◽  
Muthi Ikawati ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Cell Senescence ◽  
Dependent Manner ◽  
Protein Markers ◽  
High Concentration ◽  
Physiological Concentration ◽  
Genistein Treatment ◽  
M Phase ◽  
Induced Apoptosis

Purpose: Genistein, a soy isoflavone, exhibits a biphasic effect on cells proliferation with some different effects between ER-alpha and ER-beta. The objective of this present study is to determine the modulatory effect based on cell cycle progression under genistein treatment in combination with 17-β estradiol (E2) on CHO-K1 cells. Methods: The effect of genistein 0.1-100 µM on cells proliferation was examined by MTT assay. The modulation of genistein and estradiol (E2) on cell cycle and apoptosis were observed by using flowcytometry with PI and PI/AnnexinV staining, respectively. Moreover, the effect of genistein and E2 on senescence cells, and ROS level were determined by senescence-associated β-galactosidase (SA β-gal) staining and by using flowcytometry with 2’, 7’–dichlorofluorescin diacetate (DCFDA) staining, respectively. The expression level of the cell cycle and senescence protein markers were observed by immunoblotting. Results: Single treatment of genistein at physiologically achievable (low) concentration (<2 µM) induced proliferation of CHO-K1 cells while at a pharmacological (high) concentration (50 and 100 µM) suppressed cells proliferation. Interestingly, treatment of genistein at the physiological concentration in combination with E2 for 24, 48 and 72 h decreased cells viability on CHO-K1 cells compared to untreated cells. Further analysis of the cells showed that 50 µM genistein induced G2/M phase accumulation and induced apoptosis. Moreover, genistein induced cell senescence and increased ROS level. Immunoblotting analysis showed the decreasing of ERalpha, Bcl2, and ppRb protein level upon treatment of 1 µM Gen and 1 nM E2. Conclusion: Our results suggest that the cell proliferation inhibitory mechanism of genistein at pharmacological concentration involved the induction of cell senescence, and the elevation of ROS level. Moreover, the decreased of cells proliferation upon treatment of physiological concentration of genistein in combination with E2 may be correlated with the alteration of ER expression.

scholarly journals Melatonin-induced Cell Rejuvenation from Long-term Ex-vivo passaging Functioned by its Restoration of Damaged Cell Autophagic Processes

2020 ◽  
Author(s):  
Yi-Zhou Tan ◽  
Xin-Yue Xu ◽  
Ji-Min Dai ◽  
Yuan Yin ◽  
Xiao-Tao He ◽  
...  
Keyword(s):  
Stem Cells ◽  
Signaling Pathway ◽  
Cellular Senescence ◽  
Ex Vivo ◽  
Mtor Signaling ◽  
Beclin 1 ◽  
Dependent Manner ◽  
Mtor Signaling Pathway ◽  
Associated Proteins

Abstract Background: Stem cells undergone long-term ex-vivo expansion are most likely functionally compromised (namely cellular senescence) in terms of their stem cell properties and therapeutic potentials. Due to the ability to attenuate cellular senescence, melatonin (MLT) has been proposed as an adjuvant across long-term cell expansion protocols, but the underlying mechanism remains largely unknown. Methods: Human periodontal ligament stem cells (PDLSCs) were isolated and cultured ex-vivo for 15 passages, and passage 2, 7 and 15 cells were used to interrogate the cellular senescence and alteration in cell autophagy during long-term expansion. The cellular senescence features were evidenced by senescence-associated β-galacotosidase (SA-β-gal) activity and the expression of senescence-related proteins including p53, p21, p16 and γ-H2AX. Electronic microscope was used to observe the autophagic vesicles. Adenovirus mRFP-GFP-LC3 was transfected to indicate the alteration of autophagic flux during long-term expansion, and the autophagy-associated proteins Atg7, Beclin-1, LC3-II and p62 were evaluated by Western blot. Results: It was found that long-term in-vitro passaging led to an accumulated SA-β-gal, elevated expressions of p53, p21, p16 and γ-H2AX, along with downregulated autophagy-associated proteins Atg7, Beclin-1 and LC3 as well as a mounting autophagy substrate p62. In accordance with expectation, supplemented with MLT not only ameliorated cells to a younger state but also restored the impaired autophagy level in senescent cells. Additionally, we demonstrated that autophagy inhibitor could block such MLT-induced cell rejuvenation. When the underlying signaling pathways involved was interrogated, we found that MLT receptor (MT) participated in mediating MLT-related autophagy restoration by regulating PI3K/AKT/mTOR signaling pathway.Conclusions: The present study suggests that MLT may rejuvenate long-term expansion-caused cellular senescence by restoring autophagy, more likely via PI3K/AKT/mTOR signaling pathway in an MT-dependent manner. This is the first report identifying the MT-dependent PI3K/AKT/mTOR signaling involved in MLT-induced autophagy alteration, pointing to a potential target for using autophagy-restoring agents such as MLT to develop optimized clinical-scale cell production protocols.

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