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Tesei A, Leonetti C, Di Donato M, Gabucci E, Porru M, Varchi G, Guerrini A, Amadori D, Arienti C, Pignatta S, Paganelli G, Caraglia M, Castoria G, Zoli W. Effect of small molecules modulating androgen receptor (SARMs) in human prostate cancer models. PLoS One 2013; 8:e62657. [PMID: 23667504 PMCID: PMC3648536 DOI: 10.1371/journal.pone.0062657] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 03/25/2013] [Indexed: 01/03/2023] Open
Abstract
The management of hormone-refractory prostate cancer represents a major challenge in the therapy of this tumor, and identification of novel androgen receptor antagonists is needed to render treatment more effective. We analyzed the activity of two novel androgen receptor antagonists, (S)-11 and (R)-9, in in vitro and in vivo experimental models of hormone-sensitive or castration-resistant prostate cancer (CRPC). In vitro experiments were performed on LNCaP, LNCaP-AR, LNCaP-Rbic and VCaP human prostate cancer cells. Cytotoxic activity was assessed by SRB and BrdU uptake, AR transactivation by luciferase reporter assay and PSA levels by Real Time RT-PCR and ELISA assays. Cell cycle progression-related markers were evaluated by western blot. In vivo experiments were performed on SCID mice xenografted with cells with different sensitivity to hormonal treatment. In hormone-sensitive LNCaP and LNCaP-AR cells, the latter expressing high androgen receptor levels, (R)-9 and (S)-11 exhibited a higher cytotoxic effect compared to that of the reference compound ((R)-bicalutamide), also in the presence of the synthetic androgen R1881. Furthermore, the cytotoxic effect produced by (R)-9 was higher than that of (S)-11 in the two hormone-resistant LNCaP-AR and VCaP cells. A significant reduction in PSA levels was observed after exposure to both molecules. Moreover, (S)-11 and (R)-9 inhibited DNA synthesis by blocking the androgen-induced increase in cyclin D1 protein levels. In vivo studies on the toxicological profile of (R)-9 did not reveal the presence of adverse events. Furthermore, (R)-9 inhibited tumor growth in various in vivo models, especially LNCaP-Rbic xenografts, representative of recurrent disease. Our in vitro results highlight the antitumor activity of the two novel molecules (R)-9 and (S)-11, making them a potentially attractive option for the treatment of CRPC.
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Affiliation(s)
- Anna Tesei
- Biosciences Laboratory, IRCCS Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST), Meldola, Italy
- * E-mail: (AT); (CL)
| | - Carlo Leonetti
- Department of Experimental Oncology, Laboratory of Experimental Preclinical Chemotherapy, National Cancer Institute “Regina Elena”, Rome, Italy
- * E-mail: (AT); (CL)
| | - Marzia Di Donato
- Department of General Pathology, II University of Naples, Naples, Italy
| | - Elisa Gabucci
- Biosciences Laboratory, IRCCS Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST), Meldola, Italy
| | - Manuela Porru
- Department of Experimental Oncology, Laboratory of Experimental Preclinical Chemotherapy, National Cancer Institute “Regina Elena”, Rome, Italy
| | - Greta Varchi
- Italian National Research Council, Institute for Organic Chemistry and Photoreactivity, Bologna, Italy
| | - Andrea Guerrini
- Italian National Research Council, Institute for Organic Chemistry and Photoreactivity, Bologna, Italy
| | - Dino Amadori
- Department of Medical Oncology, IRCCS Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST), Meldola, Italy
| | - Chiara Arienti
- Biosciences Laboratory, IRCCS Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST), Meldola, Italy
| | - Sara Pignatta
- Biosciences Laboratory, IRCCS Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST), Meldola, Italy
| | - Giulia Paganelli
- Biosciences Laboratory, IRCCS Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST), Meldola, Italy
| | - Michele Caraglia
- Department of Biochemistry and Biophysics, Second University of Naples, Naples, Italy
| | | | - Wainer Zoli
- Biosciences Laboratory, IRCCS Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST), Meldola, Italy
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Taplin ME. Androgen receptor: role and novel therapeutic prospects in prostate cancer. Expert Rev Anticancer Ther 2008; 8:1495-508. [PMID: 18759700 DOI: 10.1586/14737140.8.9.1495] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Androgen receptor (AR) signaling is necessary for the development of prostate cancer. Androgen-deprivation therapy (ADT) for prostate cancer was described over 50 years ago and ADT remains the mainstay of systemic therapy. AR signaling remains intact as the disease evolves to castration-resistant prostate cancer (CRPC). Through cellular adaptations, CRPC continues to rely on androgens and AR growth signaling, and thus AR remains an important therapeutic target. CRPC cells upregulate enzymes used in androgen synthesis, thus providing an intracellular source of androgen despite systemic castration. Compounds in development, such as antiandrogens, lyase inhibitors, heat-shock protein-90 inhibitors, histone deacetylase inhibitors and others, will provide new tools to more effectively reduce ligand, inhibit AR and/or inhibit costimulatory pathways and result in improved clinical outcomes.
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Affiliation(s)
- Mary-Ellen Taplin
- Harvard Medical School, Dana-Farber Cancer Institute, Lank Center for Genitourinary Oncology, 44 Binney Street, Boston, MA 02115, USA.
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Taplin ME. Drug Insight: role of the androgen receptor in the development and progression of prostate cancer. ACTA ACUST UNITED AC 2007; 4:236-44. [PMID: 17392714 DOI: 10.1038/ncponc0765] [Citation(s) in RCA: 150] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2006] [Accepted: 12/08/2006] [Indexed: 11/09/2022]
Abstract
Functional androgen receptor (AR) signaling is necessary for the development of prostate cancer. The therapeutic effect of androgen deprivation therapy for prostate cancer was described over 60 years ago and this treatment remains the mainstay of systemic therapy despite its transient response duration. It has become clear that AR expression and signaling remains intact as the disease evolves from androgen-sensitive cancer to classically (but perhaps inaccurately) termed hormone refractory prostate cancer. Through several genetic and epigenetic adaptations, prostate tumors continue to rely on AR growth signaling and they thus remain targets of 'hormonal' therapy. The development of new strategies and drugs that can abrogate AR signaling will probably result in important clinical benefits. The biology of androgen independence and the development of new approaches targeting AR signaling are reviewed herein.
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Affiliation(s)
- Mary-Ellen Taplin
- Harvard Medical School, Lank Center for Genitourinary Oncology, Dana-Farber Cancer Institute, 44 Binney Street, Boston, MA 02115, USA.
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Palmer S, Campen CA, Allan GF, Rybczynski P, Haynes-Johnson D, Hutchins A, Kraft P, Kiddoe M, Lai M, Lombardi E, Pedersen P, Hodgen G, Combs DW. Nonsteroidal progesterone receptor ligands with unprecedented receptor selectivity. J Steroid Biochem Mol Biol 2000; 75:33-42. [PMID: 11179906 DOI: 10.1016/s0960-0760(00)00134-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We have characterized a series of nonsteroidal progesterone receptor ligands, the tetrahydropyridazines. Compounds in this series, exemplified by RWJ 26819, demonstrate high affinity and unprecedented specificity for the progesterone receptor relative to other steroid hormone receptors. Like steroidal progestins, RWJ 26819 induces binding of the receptor to a progesterone response element in vitro, and stimulates gene expression in and proliferation of T47D human breast cancer cells. When administered to rabbits orally or subcutaneously, the compound induces histological changes in the uterine lining comparable to those induced by levonorgestrel. It also inhibits ovulation in monkeys. Though less potent in cells and in animal models than would be predicted from binding affinity alone, their enhanced selectivity suggests that they could be effectively used in a clinical setting. Most of the tetrahydropyridazines synthesized are progestin agonists or mixed agonists and antagonists in vitro; however, one compound with antagonist activity in the rabbit uterine transformation assay has been identified.
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Affiliation(s)
- S Palmer
- R.W. Johnson Pharmaceutical Research Institute, 1000 Route 202, PO Box 300, Raritan, NJ 08869, USA
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Abstract
Androgens exert profound effects on the organization and function of the central nervous system. These effects are mediated by the androgen receptor (AR), a ligand-dependent transcription factor. The mechanisms of AR regulation in neural tissue, however, remain to be fully elucidated. Characterizing this process can provide important information regarding receptor function and AR gene regulation in the brain. Previously, it was shown that testosterone (T) up-regulated neural AR in a dose-dependent manner in both male and female mice. In the present study, whether AR was differentially regulated by the natural agonists T and dihydrotestosterone (DHT) or the nonsteroidal antagonist flutamide (FLU) was assessed. Males were gonadectomized and AR levels were allowed to decline to baseline 3 days after surgery. Changes in AR protein content produced by the various treatments were measured by semiquantitative Western blot of limbic system extracts. Treatment with T or DHT significantly augmented AR 3 and 7 h after hormone administration, but only DHT sustained this increase for 21 h. This difference also was observed when males were given T plus finasteride (FIN, a 5alpha reductase inhibitor). The findings demonstrate that the two endogenous ligands have differential time course effects on neural AR. The antiandrogen FLU failed to up-regulate AR at doses up to 100 times higher than T or DHT. When administered concomitantly with T or DHT, it effectively inhibited the augmentation of AR normally seen 3 h after androgen treatment. While immunohistochemical studies showed that FLU was able to promote nuclear translocation of AR, Western analysis revealed that FLU, in contrast to T and DHT, failed to maintain the integrity of AR. The results demonstrate that (a) the endogenous androgens T and DHT regulate AR differently, suggesting a potential cellular mechanism that may contribute to the difference in neural target gene sensitivity to these androgens; (b) up-regulation of AR occurs only in the presence of agonists; (c) the mechanism of action of FLU in the brain involves inhibition of AR protein up-regulation normally seen in response to androgen; and (d) FLU promotes AR nuclear translocation but not augmentation of cellular AR populations. These findings demonstrate that in vivo AR regulation in the brain basically parallels mechanisms proposed from results obtained with transfected cells and cell lines.
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Affiliation(s)
- S Lu
- Department of Biological Sciences, 111 Research Drive, Lehigh University, Bethlehem, Pennsylvania 18015, USA
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Roy AK, Lavrovsky Y, Song CS, Chen S, Jung MH, Velu NK, Bi BY, Chatterjee B. Regulation of androgen action. VITAMINS AND HORMONES 1999; 55:309-52. [PMID: 9949684 DOI: 10.1016/s0083-6729(08)60938-3] [Citation(s) in RCA: 175] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- A K Roy
- Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio 78284-7762, USA
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Umekita Y, Hiipakka RA, Kokontis JM, Liao S. Human prostate tumor growth in athymic mice: inhibition by androgens and stimulation by finasteride. Proc Natl Acad Sci U S A 1996; 93:11802-7. [PMID: 8876218 PMCID: PMC38139 DOI: 10.1073/pnas.93.21.11802] [Citation(s) in RCA: 135] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
When the human prostate cancer cell line, LNCaP 104-S, the growth of which is stimulated by physiological levels of androgen, is cultured in androgen-depleted medium for > 100 passages, the cells, now called LNCaP 104-R2, are proliferatively repressed by low concentrations of androgens. LNCaP 104-R2 cells formed tumors in castrated male athymic nude mice. Testosterone propionate (TP) treatment prevented LNCaP 104-R2 tumor growth and caused regression of established tumors in these mice. Such a tumor-suppressive effect was not observed with tumors derived from LNCaP 104-S cells or androgen receptor-negative human prostate cancer PC-3 cells. 5 alpha-Dihydrotestosterone, but not 5 beta-dihydrotestosterone, 17 beta-estradiol, or medroxyprogesterone acetate, also inhibited LNCaP 104-R2 tumor growth. Removal of TP or implantation of finasteride, a 5 alpha-reductase inhibitor, in nude mice bearing TP implants resulted in the regrowth of LNCaP 104-R2 tumors. Within 1 week after TP implantation, LNCaP 104-R2 tumors exhibited massive necrosis with severe hemorrhage. Three weeks later, these tumors showed fibrosis with infiltration of chronic inflammatory cells and scattered carcinoma cells exhibiting degeneration. TP treatment of mice with LNCaP 104-R2 tumors reduced tumor androgen receptor and c-myc mRNA levels but increased prostate-specific antigen in serum- and prostate-specific antigen mRNA in tumors. Although androgen ablation has been the standard treatment for metastatic prostate cancer for > 50 years, our study shows that androgen supplementation therapy may be beneficial for treatment of certain types of human prostate cancer and that the use of 5 alpha-reductase inhibitors, such as finasteride or anti-androgens, in the general treatment of metastatic prostate cancer may require careful assessment.
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Affiliation(s)
- Y Umekita
- Ben May Institute for Cancer Research, Department of Biochemistry and Molecular Biology, University of Chicago, IL 60637, USA
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Abstract
Androgen-ablative therapy for metastatic prostate cancer is effective for 60%-80% of men, but its effects are always finite and the majority of men develop androgen-independent disease within two years. Although current therapies for androgen-independent disease have not been shown to impact on survival, recent clinical and laboratory insights offer hope for effective therapy. For instance, recent data indicate that androgen-independent disease may still be dependent on hormonal stimulation, suggesting that hormonally based therapies may provide continued benefit. Chemotherapy, especially with estramustine and etoposide, seems to be an effective combination for a majority of patients. Treatment with suramin had been hampered by its side effects, but new dosing schedules are effectively circumventing toxicity. Radioisotopes such as strontium 89 have been shown to provide effective palliation for a majority of androgen-independent patients. Overall, these and other emerging efforts may be the foundation for therapies that offer hope for a significant survival benefit.
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Affiliation(s)
- GJ Bubley
- Beth Israel Hospital and Harvard Medical School, Division of Hematology/Oncology, Boston, Massachusetts, 02215, USA
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