scholarly journals 3β-Hydroxysteroid Dehydrogenase Is a Possible Pharmacological Target in the Treatment of Castration-Resistant Prostate Cancer

Endocrinology ◽  
2010 ◽  
Vol 151 (8) ◽  
pp. 3514-3520 ◽  
Author(s):  
Kristen Evaul ◽  
Rui Li ◽  
Mahboubeh Papari-Zareei ◽  
Richard J. Auchus ◽  
Nima Sharifi
Keyword(s):  
Prostate Cancer ◽  
Cell Proliferation ◽  
Androgen Receptor ◽  
Nuclear Translocation ◽  
De Novo ◽  
Hydroxysteroid Dehydrogenase ◽  
Adrenal Steroids ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant ◽  
Pharmacological Target

Prostate cancer usually responds to androgen deprivation therapy, although the response in metastatic disease is almost always transient and tumors eventually progress as castration-resistant prostate cancer (CRPC). CRPC continues to be driven by testosterone or dihydrotestosterone from intratumoral metabolism of 19-carbon adrenal steroids from circulation, and/or de novo intratumoral steroidogenesis. Both mechanisms require 3β-hydroxysteroid dehydrogenase (3βHSD) metabolism of Δ5-steroids, including dehydroepiandrosterone (DHEA) and Δ5-androstenediol (A5diol), to testosterone. In contrast, reports that DHEA and A5diol directly activate the androgen receptor (AR) suggest that 3βHSD metabolism is not required and that 3βHSD inhibitors would be ineffective in the treatment of CRPC. We hypothesized that activation of AR in prostate cancer by DHEA and A5diol requires their conversion via 3βHSD to androstenedione and testosterone, respectively. Here, we show that DHEA and A5diol induce AR chromatin occupancy and AR-regulated genes. Furthermore, we show that Δ5-androgens undergo 3β-dehydrogenation in prostate cancer and that induction of AR nuclear translocation, AR chromatin occupancy, transcription of PSA, TMPRSS2, and FKBP5, as well as cell proliferation by DHEA and A5diol, are all blocked by inhibitors of 3βHSD. These findings demonstrate that DHEA and A5diol must be metabolized by 3βHSD to activate AR in these models of CRPC. Furthermore, this work suggests that 3βHSD may be exploited as a pharmacologic target in the treatment of CRPC.

scholarly journals Activation of GPR56, a novel adhesion GPCR, is necessary for nuclear androgen receptor signaling in prostate cells

2019 ◽  
Author(s):  
Julie Pratibha Singh ◽  
Manisha Dagar ◽  
Gunjan Dagar ◽  
Sudhir Rawal ◽  
Ravi Datta Sharma ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Intracellular Signaling ◽  
Target Genes ◽  
Nuclear Translocation ◽  
Prostate Tumor ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant ◽  
Pka Pathway ◽  
Adhesion Gpcr

AbstractThe androgen receptor (AR) is activated in patients with castration resistant prostate cancer (CRPC) despite low circulating levels of androgen, suggesting that intracellular signaling pathways and non-androgenic factors may contribute to AR activation. Many G-protein coupled receptors (GPCR) and their ligands are also activated in these cells indicating a role for these in CRPC. Although a cross talk has been suggested between the two pathways, yet, the identity of GPCRs which may play a role in androgen signaling, is not established yet. We demonstrate that adhesion GPCR 205, also known as GPR56, can be activated by androgens to stimulate the Rho signaling pathway, a pathway that plays an important role in prostate tumor cell metastasis. Testosterone stimulation of GPR56 also activates the cAMP/ Protein kinase A (PKA) pathway, that is necessary for AR signaling. Knocking down the expression of GPR56 using siRNA, disrupts nuclear translocation of AR and transcription of prototypic AR target genes such as PSA. GPR56 expression is higher in all prostate tumor samples tested and cells expressing GPR56 exhibit increased proliferation. These findings provide new insights about androgen signaling and identify GPR56 as a possible therapeutic target in advanced prostate cancer patients.

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.

Inhibition of 3β-hydroxysteroid dehydrogenase by abiraterone: A rationale for increasing drug exposure in castration-resistant prostate cancer.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 4645-4645
Author(s):  
Nima Sharifi ◽  
Rui Li ◽  
Kristen Evaul ◽  
Kamalesh Sharma ◽  
Richard J Auchus
Keyword(s):  
Prostate Cancer ◽  
Drug Exposure ◽  
Nuclear Translocation ◽  
Hydroxysteroid Dehydrogenase ◽  
Phase Iii ◽  
Castration Resistant Prostate Cancer ◽  
Steroidogenic Enzymes ◽  
Xenograft Growth ◽  
Castration Resistant

4645 Background: Treatment with abiraterone acetate (abi) increases the survival of men with castration-resistant prostate cancer (CRPC). Resistance to abi invariably occurs, probably due in part to up-regulation of steroidogenic enzymes and/or other mechanisms that sustain the synthesis of dihydrotestosterone (DHT), which raises the possibility of reversing resistance by concomitant inhibition of other required steroidogenic enzymes. The 1,000 mg daily abi dose was selected for the phase III trials despite the absence of dose-limiting toxicities at higher doses. Based on the 3β-hydroxyl, Δ5-structure, we hypothesized that abi also inhibits 3β-hydroxysteroid dehydrogenase/isomerase (3βHSD), which is absolutely required for the intratumoral synthesis of DHT in CRPC, regardless of origins or routes of synthesis. Methods: We tested if abi inhibits recombinant 3βHSD2 activity in vitro or endogenous 3βHSD activity in LNCaP and LAPC4 cells, including conversion of [3H]-dehydroepiandrosterone (DHEA) to androstenedione (AD), androgen receptor (AR) nuclear translocation, expression of AR-responsive genes, and LAPC4 xenograft growth in orchiectomized mice supplemented with DHEA. Results: Abi has a mixed inhibition pattern of 3βHSD2 in vitro, blocks the conversion from DHEA to AD and DHT with an IC50 of < 1 µM in CRPC cell lines, inhibits AR nuclear translocation and expression of TMPRSS2, and decreases CRPC xenograft growth in DHEA-supplemented mice. Conclusions: Abi blocks 3βHSD enzymatic activity, synthesis of AD and DHT, inhibits the AR-response, and suppresses growth of CRPC cells at concentrations that are clinically achievable. Variable abi inhibition of 3βHSD might account in part for the heterogeneous clinical response to abi. More importantly, 3βHSD inhibition with abi might be clinically harnessed to reverse resistance to CYP17A1 inhibition at the standard dose by dose-escalation, or simply by administration with food to increase drug exposure.

Inhibition of 3β-hydroxysteroid dehydrogenase by abiraterone as a rationale for dose escalation in castration-resistant prostate cancer.

2012 ◽  
Vol 30 (5_suppl) ◽  
pp. 209-209
Author(s):  
Nima Sharifi ◽  
Rui Li ◽  
Kristen Evaul ◽  
Kamalesh Sharma ◽  
Richard J Auchus
Keyword(s):  
Prostate Cancer ◽  
Dose Escalation ◽  
Nuclear Translocation ◽  
Hydroxysteroid Dehydrogenase ◽  
Phase Iii ◽  
Castration Resistant Prostate Cancer ◽  
Steroidogenic Enzymes ◽  
Xenograft Growth ◽  
Castration Resistant

209 Background: Treatment with abiraterone acetate (abi) increases the survival of men with castration-resistant prostate cancer (CRPC). Resistance to abi invariably occurs, probably due in part to up-regulation of steroidogenic enzymes and/or other mechanisms that sustain the synthesis of dihydrotestosterone (DHT), which raises the possibility of reversing resistance by concomitant inhibition of other required steroidogenic enzymes. The 1000 mg daily abi dose was selected for the phase III trials despite the absence of dose-limiting toxicities at higher doses. Based on the 3β-hydroxyl, Δ5-structure, we hypothesized that abi also inhibits 3β-hydroxysteroid dehydrogenase/isomerase (3βHSD), which is absolutely required for the intratumoral synthesis of DHT in CRPC, regardless of origins or routes of synthesis. Methods: We tested if abi inhibits recombinant 3βHSD2 activity in vitro or endogenous 3βHSD activity in LNCaP and LAPC4 cells, including conversion of [3H]-dehydroepiandrosterone (DHEA) to androstenedione (AD), androgen receptor (AR) nuclear translocation, expression of AR-responsive genes, and LAPC4 xenograft growth in orchiectomized mice supplemented with DHEA. Results: Abi has a mixed inhibition pattern of 3βHSD2 in vitro, blocks the conversion from DHEA to AD and DHT with an IC50 of < 1 µM in CRPC cell lines, inhibits AR nuclear translocation and expression of TMPRSS2, and decreases CRPC xenograft growth in DHEA-supplemented mice. Conclusions: Abi blocks 3βHSD enzymatic activity, synthesis of AD and DHT, inhibits the AR-response, and suppresses growth of CRPC cells at concentrations that are clinically achievable. Variable abi inhibition of 3βHSD might account in part for the heterogeneous clinical response to abi. More importantly, 3βHSD inhibition with abi might be clinically harnessed to reverse resistance to CYP17A1 inhibition at the standard dose by dose-escalation, or simply by administration with food to increase drug exposure.

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

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.

scholarly journals Human heterochromatin protein 1 isoforms regulate androgen receptor signaling in prostate cancer

2013 ◽  
Vol 50 (3) ◽  
pp. 401-409 ◽  
Author(s):  
Momoe Itsumi ◽  
Masaki Shiota ◽  
Akira Yokomizo ◽  
Eiji Kashiwagi ◽  
Ario Takeuchi ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cell Proliferation ◽  
Androgen Receptor ◽  
Cell Growth ◽  
Critical Role ◽  
Castration Resistant Prostate Cancer ◽  
Heterochromatin Protein 1 ◽  
Heterochromatin Protein ◽  
Castration Resistant ◽  
22Rv1 Cell

Androgen receptor (AR) signaling is critical for the tumorigenesis and development of prostate cancer, as well as the progression to castration-resistant prostate cancer. We previously showed that the heterochromatin protein 1 (HP1) β isoform plays a critical role in transactivation of AR signaling as an AR coactivator that promotes prostate cancer cell proliferation. However, the roles of other HP1 isoforms, HP1α and HP1γ, in AR expression and prostate cancer remain unclear. Here, we found that knockdown of HP1γ, but not HP1α, reduced AR expression and cell proliferation by inducing cell cycle arrest at G1 phase in LNCaP cells. Conversely, overexpression of full-length HP1α and its C-terminal deletion mutant increased AR expression and cell growth, whereas overexpression of HP1γ had no effect. Similarly, HP1α overexpression promoted 22Rv1 cell growth, whereas HP1γ knockdown reduced the proliferation of CxR cells, a castration-resistant LNCaP derivative. Taken together, HP1 isoforms distinctly augment AR signaling and cell growth in prostate cancer. Therefore, silencing of HP1β and HP1γ may be a promising therapeutic strategy for treatment of prostate cancer.

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