Heme Oxygenase 1 Impairs Glucocorticoid Receptor Activity in Prostate Cancer

Glucocorticoids are used during prostate cancer (PCa) treatment. However, they may also have the potential to drive castration resistant prostate cancer (CRPC) growth via the glucocorticoid receptor (GR). Given the association between inflammation and PCa, and the anti-inflammatory role of heme oxygenase 1 (HO-1), we aimed at identifying the molecular processes governed by the interaction between HO-1 and GR. PCa-derived cell lines were treated with Hemin, Dexamethasone (Dex), or both. We studied GR gene expression by RTqPCR, protein expression by Western Blot, transcriptional activity using reporter assays, and nuclear translocation by confocal microscopy. We also evaluated the expression of HO-1, FKBP51, and FKBP52 by Western Blot. Hemin pre-treatment reduced Dex-induced GR activity in PC3 cells. Protein levels of FKBP51, a cytoplasmic GR-binding immunophilin, were significantly increased in Hemin+Dex treated cells, possibly accounting for lower GR activity. We also evaluated these treatments in vivo using PC3 tumors growing as xenografts. We found non-significant differences in tumor growth among treatments. Immunohistochemistry analyses revealed strong nuclear GR staining in almost all groups. We did not observe HO-1 staining in tumor cells, but high HO-1 reactivity was detected in tumor infiltrating macrophages. Our results suggest an association and crossed modulation between HO-1 and GR pathways.

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Alleviation of Cartilage Destruction by Sinapic Acid in Experimental Osteoarthritis

BioMed Research International ◽

10.1155/2019/5689613 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9 ◽

Cited By ~ 4

Author(s):

Dawei Cai ◽

Thomas W. Huff ◽

Jun Liu ◽

Tangbo Yuan ◽

Zijian Wei ◽

...

Keyword(s):

Heme Oxygenase ◽

Nuclear Translocation ◽

Sinapic Acid ◽

Heme Oxygenase 1 ◽

Related Factor ◽

Transactivation Activity ◽

Nrf2 Signaling Pathway ◽

Primary Mouse

Sinapic acid (SA) modulates the nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling pathway in chondrocytes. In order to test the hypothesis that SA is protective against the development of osteoarthritis (OA), primary mouse chondrocytes were treated in vitro with SA and the promoter transactivation activity of heme oxygenase 1 (HO-1), nuclear translocation of Nrf2, and protein expression of HO-1 were assayed. To test the hypothesis in vivo, a destabilization of the medial meniscus (DMM) model was used to induce OA in the knees of mice and SA was delivered orally to the experimental group. The chondrocytes were harvested for further analysis. The expression of HO-1 was similarly upregulated in cartilage from both the experimental mice and human chondrocytes from osteoarthritic knees. SA was found to enhance the promoter transactivation activity of heme oxygenase 1 (HO-1) and increase the expression of Nrf2 and HO-1 in primary chondrocytes. Histopathologic scores showed that the damage induced by the DMM model was significantly lower in the SA treatment group. The addition of a HO-1 inhibitor with SA did not show additional benefit over SA alone in terms of cartilage degradation or histopathologic scores. The expression of TNF-α, IL-1β, IL-6, MMP-1, MMP-3, MMP-13, ADAMTS4, and ADAMTS5 was significantly reduced both in vitro and in vivo by the presence of SA. Protein expressions of HO-1 and Nrf2 were substantially increased in knee cartilage of mice that received oral SA. Our results suggest that SA should be further explored as a preventative treatment for OA.

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Heme oxygenase expression and Nrf2 signaling during hibernation in ground squirrelsThis article is one of a selection of papers published in a Special Issue on Oxidative Stress in Health and Disease.

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y10-017 ◽

2010 ◽

Vol 88 (3) ◽

pp. 379-387 ◽

Cited By ~ 26

Author(s):

Zhouli Ni ◽

Kenneth B. Storey

Keyword(s):

Oxidative Stress ◽

Heme Oxygenase ◽

Nuclear Translocation ◽

Muscle Power ◽

Ground Squirrels ◽

Heme Oxygenase 1 ◽

Antioxidant Defences ◽

Protein Levels ◽

Brown Adipose ◽

Distribution Studies

Mammalian hibernation is composed of long periods of deep torpor interspersed with brief periods of arousal in which the animals, fueled by high rates of oxygen-based thermogenesis in brown adipose tissue and skeletal muscle, power themselves back to euthermic (~37 °C) body temperatures. Strong antioxidant defences are important both for long-term cytoprotection during torpor and for coping with high rates of reactive oxygen species generated during arousal. The present study shows that the antioxidant enzyme heme oxygenase 1 (HO1) is strongly upregulated in selected organs of thirteen-lined ground squirrels (Spermophilus tridecemlineatus) during hibernation. Compared with euthermic controls, HO1 mRNA transcript levels were 1.4- to 3.8-fold higher in 5 organs of hibernating squirrels, whereas levels of the constitutive isozyme HO2 were unchanged. Similarly, HO1 protein levels increased by 1.5- to 2.0-fold in liver, kidney, heart, and brain during torpor. Strong increases in the levels of the Nrf2 transcription factor and its heterodimeric partner protein, MafG, in several tissues indicated the mechanism of activation of hibernation-responsive HO1 gene expression. Furthermore, subcellular distribution studies with liver showed increased nuclear translocation of both Nrf2 and MafG in torpid animals. The data are consistent with the suggestion that Nrf2-mediated upregulation of HO1 expression provides enhanced antioxidant defence to counter oxidative stress in hibernating squirrels during torpor and (or) arousal.

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

Frontiers in Oncology ◽

10.3389/fonc.2021.615568 ◽

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.

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ODM-204: A novel dual inhibitor of CYP17A1 and androgen receptor for the treatment of castration-resistant prostate cancer—Preclinical data.

Journal of Clinical Oncology ◽

10.1200/jco.2015.33.7_suppl.221 ◽

2015 ◽

Vol 33 (7_suppl) ◽

pp. 221-221

Author(s):

Riikka Oksala ◽

Anu Moilanen ◽

Reetta Riikonen ◽

Petteri Rummakko ◽

Riikka Huhtaniemi ◽

...

Keyword(s):

Prostate Cancer ◽

Androgen Receptor ◽

Nuclear Translocation ◽

Leuprolide Acetate ◽

Male Rats ◽

Castration Resistant Prostate Cancer ◽

Dual Inhibitor ◽

Castration Resistant

221 Background: Castration-resistant prostate cancer (CRPC) is characterized by high androgen receptor (AR) expression and persistent activation of AR signaling axis by residual tissue/tumor androgens. Targeting AR and androgen biosynthesis together may be more effective than either alone. ODM-204 is a novel, non-steroidal dual inhibitor of CYP17A1 and AR, which has shown promising results in preclinical studies. Methods: The binding affinity of ODM-204 to wild type AR was determined in rat prostate cytosolic lysates. The potency and functional activity of ODM-204 to human AR were demonstrated in cells stably transfected with the full-length AR and androgen-responsive reporter gene constructs. In addition, assays for AR nuclear translocation and the transactivation of human AR mutants T877A, W741L, and F876L were conducted. The effects of ODM-204 on the growth of androgen-dependent VCaP and LNCaP cells in vitro and subcutaneously grafted VCaP cells in vivo with the oral dose of 50 mg/kg/day were studied. The inhibition of CYP17A1 by ODM-204 was studied in vitro by using human and rat testicular microsomes and a human adrenal cortex cell line, and in vivo in male rats coadministered with luteinizing hormone releasing hormone agonist leuprolide acetate to mimic clinical situation. Results: ODM-204 is a potent inhibitor of both AR and CYP17A1. It binds to AR with a high affinity (Ki=47 nM) and selectivity and has a high potency towards CYP17A1 (IC50=22 nM). In addition, ODM-204 inhibited testosterone-mediated nuclear translocation of AR and the mutant ARs (IC50 values for AR(T877A), AR(W741L), and AR(F876L) were 95, 277, and 6 nM, respectively), and suppressed androgen-induced cell proliferation of LNCaP (IC50=170 nM) and VCaP (IC50=280 nM) cells. In a VCaP xenograft model, ODM-204 showed significant antitumor activity (tumor growth inhibition=66%). In rats, inhibitory effects of leuprolide acetate on testosterone production and androgen-sensitive organ weights were potentiated by ODM-204. Conclusions: ODM-204 is a promising new dual CYP17A1 and AR inhibitor for the treatment of CRPC. Clinical trials in patients with mCRPC will be started in early 2015.

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Targeting ADT-Induced Activation of the E3 Ubiquitin Ligase Siah2 to Delay the Occurrence of Castration-Resistant Prostate Cancer

Frontiers in Oncology ◽

10.3389/fonc.2021.637040 ◽

2021 ◽

Vol 11 ◽

Author(s):

Tingmang Yan ◽

Dapeng Zhou ◽

Youwei Shi ◽

Di Cui ◽

Juntao Jiang ◽

...

Keyword(s):

Prostate Cancer ◽

Protein Expression ◽

Ubiquitin Ligase ◽

E3 Ubiquitin Ligase ◽

E3 Ligase ◽

Castration Resistant Prostate Cancer ◽

Vitamin K3 ◽

Protein Levels ◽

Castration Resistant

Siah2 is an E3 ubiquitin ligase that targets androgen receptor (AR) and plays an important role in the development of castration-resistant prostate cancer (CRPC). However, the regulation of Siah2 in prostate cancer (PCa) is largely unknown. In this study, we used AR-dependent and -independent cells lines to investigate the cellular roles of AR and androgen deprivation therapy (ADT) on Siah2 protein levels and E3 ligase activity using Western blotting and co-immunoprecipitation. We also validated our findings using patient samples taken before and after ADT. Finally, we used xenograft tumor models to test the effects of ADT combined with vitamin K3 (Vit K3) on tumor growth in vivo. Our results showed that AR stabilizes Siah2 protein by attenuating its self-ubiquitination and auto-degradation, likely by blocking its E3 ubiquitin ligase activity. Conversely, ADT decreased Siah2 protein expression but enhanced its E3 ligase activity in PCa cells. Notably, the findings that ADT decreasing Siah2 protein expression were verified in a series of paired PCa samples from the same patient. Additionally, we found that ADT-induced Siah2 activation could be abolished by Vit K3. Strikingly, ADT combined with Vit K3 treatment delayed the occurrence of CRPC and dramatically inhibited the growth of tumor xenografts compared with ADT treatment alone. AR is an inhibitor of Siah2 in PCa, and ADT leads to the continuous activation of Siah2, which may contribute to CRPC. Finally, ADT+Vit K3 may be a potential approach to delay the occurrence of CRPC.

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A novel selective therapeutic targeting heme oxygenase-1 revealed a potent antimetastatic activity in androgen-refractory human prostate cancer models

Journal of Clinical Oncology ◽

10.1200/jco.2009.27.15_suppl.e16090 ◽

2009 ◽

Vol 27 (15_suppl) ◽

pp. e16090-e16090

Author(s):

M. A. Alaoui-Jamali ◽

A. Gupta ◽

W. A. Szarek ◽

T. A. Bismar ◽

R. Gheorghe ◽

...

Keyword(s):

Oxidative Stress ◽

Prostate Cancer ◽

Cell Proliferation ◽

Heme Oxygenase ◽

Lung Metastases ◽

Heme Oxygenase 1 ◽

Hormone Refractory ◽

Novel Therapeutic

e16090 Prostate cancer is a highly prevalent disease. Despite a significant improvement in the overall survival attributed in part to early detection and introduction of novel therapeutic modalities, many cancer patients at primary diagnosis present advanced disease or experience recurrence of the cancer. The progression of prostate cancer (PCA) to hormone-refractory phenotype (HRPCA) and to metastasis is an ominous event in patients with advanced PCA. Currently, clinically available drugs for hormone refractory PCA have only marginal efficacy. In this study, we identified heme oxygenase 1 (HO-1) to be significantly upregulated in epithelial PCA cells, but not in surrounding stromal cells, from hormone refractory prostate cancer cases compared to hormone-responsive prostate cancer and to benign tissues. We validated HO-1 as a novel therapeutic target for HRPCA. Specifically, inhibition of HO-1 gene in androgen-independent and highly invasive prostate cancer cells, PC3M, decreased HO-1 activity, oxidative stress, MAPKs activation, cell proliferation, and cell migration and invasion in vitro, as well as inhibition of prostate tumor growth and lymph nodes and lung metastases in vivo. The impact of HO-1 silencing on these oncogenic features was mimicked by exposure of cells to a novel selective small-molecule HO-1 inhibitor referred to as OB-24. OB-24 selectively downregulates HO-1 activity, oxidative stress, and significantly inhibits cell proliferation in vitro and tumor growth and lymph node/lung metastases in vivo. A potent synergistic activity in inhibiting HRPCA metastasis formation was observed when OB-24 was combined with the chemotherapy drug taxol. The molecular and potential clinical impact of OB-24 alone and in combination with taxanes on HRPCA will be discussed. [Table: see text]

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Macrophage-derived cholesterol contributes to therapeutic resistance in prostate cancer

10.1101/2021.03.24.436480 ◽

2021 ◽

Author(s):

Asmaa El-Kenawi ◽

William Dominguez-Viqueira ◽

Min Liu ◽

Shivanshu Awasthi ◽

Aysenur Keske ◽

...

Keyword(s):

Prostate Cancer ◽

Cancer Progression ◽

Nuclear Translocation ◽

Cholesterol Metabolism ◽

Therapeutic Potential ◽

Cholesterol Homeostasis ◽

Castration Resistant Prostate Cancer ◽

Macrophage Depletion

Tumor-associated macrophages are key immune cells associated with cancer progression. Here we sought to determine the role of macrophages in castration-resistant prostate cancer (CRPC) using a syngeneic model that reflected the mutational landscape of the disease. A transcriptomic analysis of CRPC tumors following macrophage depletion revealed lower molecular signatures for steroid and bile acid synthesis, indicating potential perturbation of cholesterol metabolism. Since cholesterol is the precursor of the five major classes of steroid hormones, we reasoned that macrophages were regulating androgen biosynthesis within the prostate tumor microenvironment. Indeed, macrophage depletion reduced the levels of androgens within prostate tumors and restricted androgen receptor (AR) nuclear localization in vitro and in vivo. Macrophages were cholesterol rich and had the ability to transfer cholesterol to tumor cells in vitro, and AR nuclear translocation was inhibited by activation of Liver X Receptor (LXR)-β, the master regulator of cholesterol homeostasis. Finally, combining macrophage depletion with androgen deprivation therapy increased survival, supporting the therapeutic potential of targeting macrophages in CRPC.

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ARVib suppresses growth of advanced prostate cancer via inhibition of androgen receptor signaling

Oncogene ◽

10.1038/s41388-021-01914-2 ◽

2021 ◽

Author(s):

Chengfei Liu ◽

Cameron M. Armstrong ◽

Shu Ning ◽

Joy C. Yang ◽

Wei Lou ◽

...

Keyword(s):

Prostate Cancer ◽

Androgen Receptor ◽

Cancer Progression ◽

Nuclear Translocation ◽

Treatment Resistance ◽

Hsp70 Expression ◽

Castration Resistant Prostate Cancer ◽

Downstream Target

AbstractTargeting androgen signaling with the second-generation anti-androgen drugs, such as enzalutamide (Enza), abiraterone (Abi), apalutamide (Apal), and darolutamide (Daro), is the mainstay for the treatment of castration-resistant prostate cancer (CRPC). While these treatments are effective initially, resistance occurs frequently. Continued expression of androgen receptor (AR) and its variants such as AR-V7 despite AR-targeted therapy contributes to treatment resistance and cancer progression in advanced CRPC patients. This highlights the need for new strategies blocking continued AR signaling. Here, we identify a novel AR/AR-V7 degrader (ARVib) and found that ARVib effectively degrades AR/AR-V7 protein and attenuates AR/AR-V7 downstream target gene expression in prostate cancer cells. Mechanistically, ARVib degrades AR/AR-V7 protein through the ubiquitin-proteasome pathway mediated by HSP70/STUB1 machinery modulation. ARVib suppresses HSP70 expression and promotes STUB1 nuclear translocation, where STUB1 binds to AR/AR-V7 and promotes its ubiquitination and degradation. ARVib significantly inhibits resistant prostate tumor growth and improves enzalutamide treatment in vitro and in vivo. These data suggest that ARVib has potential for development as an AR/AR-V7 degrader to treat resistant CRPC.

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TAS3681: New class of androgen receptor antagonist with androgen receptor downregulating activity.

Journal of Clinical Oncology ◽

10.1200/jco.2015.33.7_suppl.266 ◽

2015 ◽

Vol 33 (7_suppl) ◽

pp. 266-266 ◽

Cited By ~ 1

Author(s):

Kazuhisa Minamiguchi ◽

Masanao Seki ◽

Hiroki Aoyagi ◽

Daisuke Kajiwara ◽

Tomoko Mori ◽

...

Keyword(s):

Prostate Cancer ◽

Androgen Receptor ◽

Nuclear Translocation ◽

Xenograft Model ◽

Biological Properties ◽

Tumor Xenograft ◽

Expression Vectors ◽

Castration Resistant Prostate Cancer ◽

Androgen Receptor Antagonist

266 Background: The persistent activation of the androgen receptor (AR) signaling axis plays a major role in castration-resistant prostate cancer (CRPC). This knowledge has driven the clinical development of new inhibitors of androgen production (e.g., abiraterone) and AR signaling (e.g., enzalutamide). However, in many patients, the efficacy is short-lived and eventually resistance appears. Reactivation of AR signaling occurs by several mechanisms in CRPC. In this study, we report the biological properties of TAS3681, a new AR antagonist with AR downregulating activity, and propose this concept as a potential new approach for the treatment of CRPC. Methods: For assay of AR transactivation, COS-7 cells were transiently transfected with androgen-responsive reporter gene construct and expression vectors encoding wt or mu ARs. The transfected cells were treated with TAS3681 and androgen in steroid depleted media for 24 h, and luciferase activity was measured. For an in vivo pharmacodynamic assay to confirm AR downregulation in tumor, TAS3681 was orally dosed in CRPC tumor xenograft model. Tumor was isolated and AR level in tumor was determined by Western blot. Results: TAS3681 suppressed the growth of AR positive prostate cancer (PCa) cells but did not affect that of AR-negative DU145 PCa cells, indicating a dependency on AR for efficacy. TAS3681 did not stimulate AR nuclear translocation and suppressed wt and mu ARs (including F876L) transactivation in cells, indicative of its pure AR antagonist profile. In contrast to enzalutamide, TAS3681 effectively suppressed androgen-independent AR transactivation by growth factors and cytokines via AR downregulating activity. Interestingly, in PCa cells which express full-length and splice variant AR, TAS3681 reduced the expression of both ARs. Moreover, TAS3681 treatment effectively decreased AR level in CRPC tumors in vivo. Conclusions: TAS3681 exerts an anti-androgenic effect via two mechanisms of action: pure AR antagonism and AR decreasing activity. It is expected that TAS3681 has a potential to overcome the resistance to current and 2nd-generation therapies targeting AR signaling.

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

Molecular Endocrinology ◽

10.1210/me.2008-0235 ◽

2009 ◽

Vol 23 (3) ◽

pp. 412-421 ◽

Cited By ~ 29

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.

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