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.

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.

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.

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.

Dasatinib and docetaxel combination treatment for patients with castration-resistant progressive prostate cancer: A phase I/II study (CA180086)

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 5061-5061 ◽  
Author(s):  
J. Araujo ◽  
A. J. Armstrong ◽  
E. L. Braud ◽  
E. Posadas ◽  
M. Lonberg ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Drug Interactions ◽  
Bone Alkaline Phosphatase ◽  
Phase Iii ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant ◽  
Best Response ◽  
Bone Scans ◽  
And Migration

5061 Background: Dasatinib, a potent inhibitor of SRC family kinases, inhibits in vitro prostate cancer cell proliferation and migration. Consistent with those findings are the clinical observations that osteoclast activity and bone turnover are downregulated in patients treated with dasatinib. We report promising preliminary results of dasatinib in combination with docetaxel (D) for treatment of metastatic castration-resistant prostate cancer (CRPC). Methods: Male pts with progressive CRPC and castrate levels of testosterone (≤50 ng/dL) requiring chemotherapy were enrolled. Escalating doses of dasatinib (50–120 mg QD) and D (60–75 mg/m2 Q 21 days) were evaluated (n = 16) followed by enrollment of 30 pts at the phase 2-selected dose (100 mg dasatinib QD + D at 75 mg/m2 Q 21 days). Continuation of bisphosphonates was permitted; anti-androgens were discontinued. Primary endpoint (Ph. 2) was to determine drug-drug interactions. Secondary endpoints were: changes in PSA, bone scans and tumor size, bone metabolism [urinary N-telopeptide (uNTX) and bone alkaline phosphatase (BAP)] and PK. Results: 46 pts were treated with 28 pts still on therapy. Median treatment duration (n = 18, pts off study) was 4.2 months (0.13–9.63). Preliminary analysis showed no interaction between dasatinib and D. PSA response was seen in 13/32 (41%) pts, clinical benefit (PR + SD) for RECIST-evaluable pts was 21/21, [7 PR, 5 uPR and 4 SD (at ≥21 wks) and 5 SD at ≥6 wk)]. Of 31 pts with bone scans, 30 patients had a best response of either improved (32%) or stable (65%) at ≥6 weeks. For pts with measurable bone markers levels, 12/26 (46%) had a ≥35% decrease in uNTX and 17/24 (71%) had a decrease in BAP from baseline. 6 of 42 pts experienced ≥ grade 3 adverse events (AEs), including fatigue, myelosuppression and pleural effusion (n = 1). Most common grade 1/2 AEs were fatigue, dysgeusia, GI, and skin disorders. Conclusions: Dasatinib and D at doses up to 120 mg QD and 75 mg/m2 are safe with manageable toxicities and no drug-drug interactions. These data confirm the antitumor and antiosteoclast activity of dasatinib in combination with D and serve as the basis for the ongoing phase III study of this combination. [Table: see text]

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.

Decreased fracture rate by mandating bone protecting agents in the EORTC 1333/PEACEIII trial combining Ra223 with enzalutamide versus enzalutamide alone: An updated safety analysis.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 5002-5002
Author(s):  
Silke Gillessen ◽  
Ananya Choudhury ◽  
Alejo Rodriguez-Vida ◽  
Franco Nole ◽  
Enrique Gallardo Diaz ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Safety Analysis ◽  
Phase Iii ◽  
Fracture Rate ◽  
Castration Resistant Prostate Cancer ◽  
Continuous Administration ◽  
Castration Resistant ◽  
Radium 223 ◽  
Safety Population

5002 Background: The randomized phase III EORTC-1333-GUCG (NCT02194842) trial compares enzalutamide vs. a combination of Radium 223 and enzalutamide in asymptomatic or mildly symptomatic metastatic castration resistant prostate cancer (mCRPC) patients. The premature unblinding of ERA223 (NCT02043678) in Nov 2017 due to a significant increase in the rate of fractures in the combination of abiraterone and Ra223 arm led to the implementation of the mandatory use of bone protecting agents (BPA) in the EORTC-1333-GUCG trial. Skeletal fractures, pathological or not, are a frequent and underestimated adverse event of systemic treatment of advanced prostate cancer. Whether this mandated use of BPA (zoledronic acid or denosumab) would mitigate the risk of fractures in this patient population was unclear. An early safety analysis (Tombal, ASCO, 2019) suggested that the risk of fractures was well controlled in both arms when patients receive BPA. We present here an updated analysis of fracture incidence with longer follow-up. Methods: As of 28/01/2021, a total of 253 patients (134 after making BPA mandatory) were randomized between enzalutamide/Ra223 and enzalutamide. The fracture rate was estimated with the cumulative incidence method in the safety population of 237 (122 after making BPA mandatory) treated patients. Death in absence of fracture was analyzed as competing risk and censoring was applied at last follow-up. Results: Overall, 69.5% of enzalutamide/Ra223 patients (95.2% after making BPA mandatory) and 73.1% of enzalutamide patients (95% after making BPA mandatory) received BPA on treatment: 13.6% in the enzalutamide/Ra223 arm and 21.8% in the enzalutamide arm did not use BPA at registration, but started during protocol treatment and 55.9% and 51.3% respectively, received BPA since entry. At 36.7 months median follow-up in patients without BPA and 23.1 months median follow-up in patients receiving BPA, a total of 39 patients reported a fracture. Among them, 30 patients (20 in enzalutamide/Ra223 arm) did not receive BPA and 9 (4 in the enzalutamide/Ra223 arm) received BPA (see table). Conclusions: The updated safety analysis confirms the early fracture rate results. In the absence of BPA, the risk of fracture is increased when RA223 is added to enzalutamide. Strikingly, in both arms, the risk remains almost abolished by a preventive continuous administration of BPA, thus stressing the importance of complying to international recommendations in terms of giving BPA to mCRPC patients. This study is sponsored by EORTC and supported by Bayer and Astellas. Clinical trial information: NCT02194842. [Table: see text]

scholarly journals MicroRNA-1205 Regulation of FRYL in Prostate Cancer

2021 ◽  
Vol 9 ◽  
Author(s):  
Michelle Naidoo ◽  
Fayola Levine ◽  
Tamara Gillot ◽  
Akintunde T. Orunmuyi ◽  
E. Oluwabunmi Olapade-Olaopa ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Neuroendocrine Differentiation ◽  
Castration Resistant Prostate Cancer ◽  
Chromosomal Locus ◽  
Protein Coding ◽  
Castration Resistant ◽  
Dendritic Branching ◽  
Very High

High mortality rates of prostate cancer (PCa) are associated with metastatic castration-resistant prostate cancer (CRPC) due to the maintenance of androgen receptor (AR) signaling despite androgen deprivation therapies (ADTs). The 8q24 chromosomal locus is a region of very high PCa susceptibility that carries genetic variants associated with high risk of PCa incidence. This region also carries frequent amplifications of the PVT1 gene, a non-protein coding gene that encodes a cluster of microRNAs including, microRNA-1205 (miR-1205), which are largely understudied. Herein, we demonstrate that miR-1205 is underexpressed in PCa cells and tissues and suppresses CRPC tumors in vivo. To characterize the molecular pathway, we identified and validated fry-like (FRYL) as a direct molecular target of miR-1205 and observed its overexpression in PCa cells and tissues. FRYL is predicted to regulate dendritic branching, which led to the investigation of FRYL in neuroendocrine PCa (NEPC). Resistance toward ADT leads to the progression of treatment related NEPC often characterized by PCa neuroendocrine differentiation (NED), however, this mechanism is poorly understood. Underexpression of miR-1205 is observed when NED is induced in vitro and inhibition of miR-1205 leads to increased expression of NED markers. However, while FRYL is overexpressed during NED, FRYL knockdown did not reduce NED, therefore revealing that miR-1205 induces NED independently of FRYL.

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