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Maestro MA, Seoane S. The Centennial Collection of VDR Ligands: Metabolites, Analogs, Hybrids and Non-Secosteroidal Ligands. Nutrients 2022; 14:nu14224927. [PMID: 36432615 PMCID: PMC9692999 DOI: 10.3390/nu14224927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/14/2022] [Accepted: 11/16/2022] [Indexed: 11/23/2022] Open
Abstract
Since the discovery of vitamin D a century ago, a great number of metabolites, analogs, hybrids and nonsteroidal VDR ligands have been developed. An enormous effort has been made to synthesize compounds which present beneficial properties while attaining lower calcium serum levels than calcitriol. This structural review covers VDR ligands published to date.
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Affiliation(s)
- Miguel A. Maestro
- Department of Chemistry-CICA, University of A Coruña, Campus da Zapateira, s/n, 15008 A Coruña, Spain
- Correspondence:
| | - Samuel Seoane
- Department of Physiology-CIMUS, University of Santiago, Campus Vida, 15005 Santiago, Spain
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2
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Malinska M, Kutner A, Woźniak K. Predicted structures of new Vitamin D Receptor agonists based on available X-ray structures. Steroids 2015; 104:220-9. [PMID: 26476188 DOI: 10.1016/j.steroids.2015.10.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 09/17/2015] [Accepted: 10/12/2015] [Indexed: 12/28/2022]
Abstract
Current efforts in the field of vitamin D are to develop 1,25(OH)2D3 analogs that exhibit equal or even increased anti-proliferative activity while possessing a reduced tendency to cause hypercalcemia. The study proposes a new, rational design of vitamin D analogs based on data available in the Protein Data Bank. Undertaken approach was to minimize the electrostatic interaction energies available after the reconstruction of charge density with the aid of the pseudoatom databank, namely the University at Buffalo Pseudoatom Databank (UBDB). Analysis of 24 vitamin D analogs, bearing similar molecular structures complexed with Vitamin D Receptor enabled the design of new agonists forming all advantageous interaction to the receptor, coded TB1, TB2, TB3 and TB4.
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Affiliation(s)
- Maura Malinska
- Department of Chemistry, University of Warsaw, 1 Pasteura, 02-093 Warsaw, Poland.
| | - Andrzej Kutner
- Pharmaceutical Research Institute, 8 Rydygiera, 01-793 Warsaw, Poland
| | - Krzysztof Woźniak
- Department of Chemistry, University of Warsaw, 1 Pasteura, 02-093 Warsaw, Poland.
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Zhang CF, Wan RZ, Liu ZP. Recent developments of 19-nor-1,25-dihydroxyvitamin D3 analogues. ChemMedChem 2013; 8:1249-60. [PMID: 23788554 DOI: 10.1002/cmdc.201300160] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 05/31/2013] [Indexed: 12/14/2022]
Abstract
The vitamin D hormone, 1α,25-dihydroxyvitamin D3 [1,25-(OH)2 D3 ], exerts its hormonal effects predominantly on intestine, bone, and kidney, where it plays a crucial role in calcium and phosphorus homeostasis and bone mineralization. In addition to its classical actions, 1,25(OH)2 D3 exerts pleiotropic effects in a wide variety of target tissues and cell types, often in an autocrine/paracrine fashion. These biological activities of 1,25(OH)2 D3 have suggested a multitude of potential therapeutic applications for the vitamin D hormone in the treatment of hyperproliferative disorders (e.g. cancer and psoriasis), immune dysfunction (autoimmune diseases), and endocrine disorders (e.g. hyperparathyroidism). However, the calcemic effects induced by 1,25(OH)2 D3--hypercalcemia, increased bone resorption, and soft tissue calcification--limit the use of the natural ligand in these clinical applications. Therefore, numerous 1,25(OH)2 D3 analogues have been synthesized with the intent of producing therapeutic agents devoid of hypercalcemic and hyperphosphatemic side effects. To this aim, much attention has been focused on the development of 19-nor-vitamin D3 derivatives that lack the ring-A exocyclic methylene group (C19). In this review, the 19-nor-1,25(OH)2 D3 analogues are classified according to modifications made at the A-ring, the side chain, or both the A-ring and side chain, as well as other positions. The biological activities of these 19-nor-1,25(OH)2 D3 analogues are summarized and their structure-activity relationships and binding features with the vitamin D receptor (VDR) are discussed.
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Affiliation(s)
- Can-Fei Zhang
- Department of Organic Chemistry, Key Laboratory of Chemical Biology, Ministry of Education, School of Pharmaceutical Sciences, Shandong University, 44, West Culture Road, Jinan 250012, P.R. China
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Huet T, Maehr H, Lee HJ, Uskokovic MR, Suh N, Moras D, Rochel N. Structure-function study of gemini derivatives with two different side chains at C-20, Gemini-0072 and Gemini-0097. MEDCHEMCOMM 2011; 2:424-429. [PMID: 22180837 DOI: 10.1039/c1md00059d] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Derivatives of vitamin D(3) containing a second side-chain emanating at C-20 are known as gemini and act as vitamin D receptor agonists. Recently, two of these, namely Gemini-0072 and the epimeric Gemini-0097, were selected for further studies in view of their high biological activities and lack of hypercalcemic effects. We now show that the two analogs recruit coactivator SRC-1 better than the parental gemini and act as VDR superagonists. The crystal structures of complexes of zVDR with Gemini-0072 and Gemini-0097 indicate that these ligands induce an extra cavity within the ligand-binding pocket similar to gemini and that their superagonistic activity is due to an increased stabilization of helix H12.
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Affiliation(s)
- Tiphaine Huet
- Département de Biologie et de Génomique Structurales, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), Centre National de la Recherche Scientifique, Institut National de la Santé de la Recherche Méedicale, Université de Strasbourg, 1 rue Laurent Fries, 67404 Illkirch, France
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Malinen M, Ryynänen J, Heinäniemi M, Väisänen S, Carlberg C. Cyclical regulation of the insulin-like growth factor binding protein 3 gene in response to 1alpha,25-dihydroxyvitamin D3. Nucleic Acids Res 2011; 39:502-12. [PMID: 20855290 PMCID: PMC3025564 DOI: 10.1093/nar/gkq820] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Accepted: 08/29/2010] [Indexed: 12/26/2022] Open
Abstract
The nuclear receptor vitamin D receptor (VDR) is known to associate with two vitamin D response element (VDRE) containing chromatin regions of the insulin-like growth factor binding protein 3 (IGFBP3) gene. In non-malignant MCF-10A human mammary cells, we show that the natural VDR ligand 1α,25-dihydroxyvitamin D(3) (1α,25(OH)(2)D(3)) causes cyclical IGFBP3 mRNA accumulation with a periodicity of 60 min, while in the presence of the potent VDR agonist Gemini the mRNA is continuously accumulated. Accordingly, VDR also showed cyclical ligand-dependent association with the chromatin regions of both VDREs. Histone deacetylases (HDACs) play an important role both in VDR signalling and in transcriptional cycling. From the 11 HDAC gene family members, only HDAC4 and HDAC6 are up-regulated in a cyclical fashion in response to 1α,25(OH)(2)D(3), while even these two genes do not respond to Gemini. Interestingly, HDAC4 and HDAC6 proteins show cyclical VDR ligand-induced association with both VDRE regions of the IGFBP3 gene, which coincides with histone H4 deacetylation on these regions. Moreover, combined silencing of HDAC4 and HDAC6 abolishes the cycling of the IGFBP3 gene. We assume that due to more efficient VDR interaction, Gemini induces longer lasting chromatin activation and therefore no transcriptional cycling but monotonically increasing IGFBP3 mRNA. In conclusion, 1α,25(OH)(2)D(3) regulates IGFBP3 transcription through short-term cyclical association of VDR, HDAC4 and HDAC6 to both VDRE-containing chromatin regions.
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Affiliation(s)
- Marjo Malinen
- Department of Biosciences, University of Eastern Finland, FIN-70210, Kuopio, Finland and Life Sciences Research Unit, University of Luxembourg, L-1511 Luxembourg, Luxembourg
| | - Jussi Ryynänen
- Department of Biosciences, University of Eastern Finland, FIN-70210, Kuopio, Finland and Life Sciences Research Unit, University of Luxembourg, L-1511 Luxembourg, Luxembourg
| | - Merja Heinäniemi
- Department of Biosciences, University of Eastern Finland, FIN-70210, Kuopio, Finland and Life Sciences Research Unit, University of Luxembourg, L-1511 Luxembourg, Luxembourg
| | - Sami Väisänen
- Department of Biosciences, University of Eastern Finland, FIN-70210, Kuopio, Finland and Life Sciences Research Unit, University of Luxembourg, L-1511 Luxembourg, Luxembourg
| | - Carsten Carlberg
- Department of Biosciences, University of Eastern Finland, FIN-70210, Kuopio, Finland and Life Sciences Research Unit, University of Luxembourg, L-1511 Luxembourg, Luxembourg
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Shabtay A, Sharabani H, Barvish Z, Kafka M, Amichay D, Levy J, Sharoni Y, Uskokovic MR, Studzinski GP, Danilenko M. Synergistic antileukemic activity of carnosic acid-rich rosemary extract and the 19-nor Gemini vitamin D analogue in a mouse model of systemic acute myeloid leukemia. Oncology 2008; 75:203-14. [PMID: 18852491 DOI: 10.1159/000163849] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Accepted: 06/05/2008] [Indexed: 01/03/2023]
Abstract
OBJECTIVE Differentiation therapy with the hormonal form of vitamin D, 1alpha,25-dihydroxyvitamin D(3) (1,25D(3)), is a promising approach to treatment of acute myeloid leukemia (AML); however, 1,25D(3) induces hypercalcemia at pharmacologically active doses. We investigated the in vitro and in vivoantileukemic efficacy of combined treatment with non-toxic doses of a low-calcemic 1,25D(3) analogue, 1,25-dihydroxy-21(3-hydroxy-3-methyl-butyl)-19-nor-cholecalciferol (19-nor-Gemini; Ro27-5646), and rosemary plant agents in a mouse model of AML. METHODS Proliferation and differentiation of WEHI-3B D- (WEHI) murine myelomonocytic leukemia cellsin vitro were determined by standard assays. Reactive oxygen species, glutathione and protein expression levels were measured by flow cytometry, enzymatic assay and Western blotting, respectively. Systemic AML was developed by intravenous injection of WEHI cells in syngeneic Balb/c mice. RESULTS 19-nor-Gemini had a higher potency than its parent compounds, Gemini (Ro27-2310) and 1,25D(3), in the induction of differentiation (EC(50) = 0.059 +/- 0.011, 0.275 +/- 0.093 and 0.652 +/- 0.085 nM, respectively) and growth arrest (IC(50) = 0.072 +/- 0.018, 0.165 +/- 0.061 and 0.895 +/- 0.144 nM, respectively) in WEHI cells in vitro, and lower in vivo toxicity. Combined treatment of leukemia-bearing mice with 19-nor-Gemini (injected intraperitoneally) and standardized rosemary extract (mixed with food) resulted in a synergistic increase in survival (from 42.2 +/- 2.5 days in untreated mice to 66.5 +/- 4.2 days, n = 3) and normalization of white blood cell and differential counts. This was consistent with strong cooperative antiproliferative and differentiation effects of low concentrations of 19-nor-Gemini or 1,25D(3) combined with rosemary extract or its major polyphenolic component, carnosic acid, as well as with the antioxidant action of rosemary agents and vitamin D derivatives in WEHI cell cultures. CONCLUSION Combined effectiveness of 1,25D(3) analogues and rosemary agents against mouse AML warrants further exploration of this therapeutic approach in translational models of human leukemia.
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Affiliation(s)
- Ayelet Shabtay
- Department of Clinical Biochemistry, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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Garay E, Jankowski P, Lizano P, Marczak S, Maehr H, Adorini L, Uskokovic MR, Studzinski GP. Calcitriol derivatives with two different side-chains at C-20. Part 4: further chain modifications that alter VDR-dependent monocytic differentiation potency in human leukemia cells. Bioorg Med Chem 2007; 15:4444-55. [PMID: 17485214 PMCID: PMC2824506 DOI: 10.1016/j.bmc.2007.04.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2007] [Accepted: 04/15/2007] [Indexed: 11/29/2022]
Abstract
Signaling of cell differentiation is one of the important physiological functions of the activated vitamin D receptor (VDR). Activation of the VDR can be achieved not only by 1alpha,25-dihydroxyvitamin D(3) (1,25D), the natural ligand, but also by a large number of its analogs. These include a category containing two side chains emanating at C-20, generally referred to as Gemini. The introduction of a cyclopropyl moiety as part of the pro-R side chain provides modified Gemini compounds with increased steric requirement and decreased chain flexibility; the biological consequences of this novel structural variant are subject of this investigation. In general, the resulting 1alpha,25-dihydroxy-(4-hydroxy-4-methyl-pentyl)-21,22-cis-cyclo-cholecalciferols reduced had differentiation and transcriptional potency and induced cell cycle arrest less efficiently, as shown by a decrease in G1/S ratio, when compared to 1,25D. Modifying their calcitriol side chain in the form of a 4-hydroxy-4-trifluoromethyl-5,5,5-trifluoropent-2-ynyl moiety, however, resulted in pronounced induction of differentiation in 1,25D-sensitive and moderate level of differentiation in 1,25D-resistant leukemia cells.
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Affiliation(s)
- Edward Garay
- Department of Pathology and Laboratory Medicine, UMDNJ-New Jersey Medical School, Newark, NJ, USA
| | | | - Paulo Lizano
- Department of Pathology and Laboratory Medicine, UMDNJ-New Jersey Medical School, Newark, NJ, USA
| | | | | | | | | | - George P. Studzinski
- Department of Pathology and Laboratory Medicine, UMDNJ-New Jersey Medical School, Newark, NJ, USA
- * Corresponding author. Tel.: +1 973 972 5869; fax: +1 973 972 7293; e-mail:
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Ciesielski F, Rochel N, Moras D. Adaptability of the Vitamin D nuclear receptor to the synthetic ligand Gemini: remodelling the LBP with one side chain rotation. J Steroid Biochem Mol Biol 2007; 103:235-42. [PMID: 17218092 DOI: 10.1016/j.jsbmb.2006.12.003] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The crystal structure of the ligand binding domain (LBD) of the wild-type Vitamin D receptor (VDR) of zebrafish bound to Gemini, a synthetic agonist ligand with two identical side chains branching at carbon 20 reveals a ligand-dependent structural rearrangement of the ligand binding pocket (LBP). The rotation of a Leu side chain opens the access to a channel that can accommodate the second side chain of the ligand. The 25% increase of the LBP's volume does not alter the essential agonist features of VDR. The possibility to adapt the LBP to novel ligands with different chemistry and/or structure opens new perspectives in the design of more specifically targeted ligands.
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Affiliation(s)
- Fabrice Ciesielski
- Département de Biologie et de Génomique Structurales, IGBMC, CNRS/INSERM Université Louis Pasteur, Parc d'innovation BP10142, 67404 Illkirch Cedex, France
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9
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Lee HJ, Liu H, Goodman C, Ji Y, Maehr H, Uskokovic M, Notterman D, Reiss M, Suh N. Gene expression profiling changes induced by a novel Gemini Vitamin D derivative during the progression of breast cancer. Biochem Pharmacol 2006; 72:332-43. [PMID: 16737686 DOI: 10.1016/j.bcp.2006.04.030] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2006] [Revised: 04/21/2006] [Accepted: 04/21/2006] [Indexed: 11/20/2022]
Abstract
We investigated gene expression changes induced by a novel Gemini Vitamin D(3) analog, RO-438-3582 (1alpha,25-dihydroxy-20S-21(3-hydroxy-3-methyl-butyl)-23-yne-26,27-hexafluoro-cholecalciferol, Ro3582), in a unique human breast MCF10 model. We used two breast epithelial cell lines from this model, namely MCF10AT1 (Ha-ras oncogene transfected MCF10A, early premalignant) and MCF10CA1a (fully malignant and metastatic derived from the MCF10AT1 line). We analyzed gene expression changes induced by Ro3582 using GeneChip technology, quantitative RT-PCR, Western blot analysis, or a gene transcription assay. Interestingly, we found distinct gene expression profile differences between Ro3582-induced response of the early premalignant MCF10AT1 and the malignant and metastatic MCF10CA1a cell lines. Moreover, while the Gemini Vitamin D(3) analog Ro3582 modulated the expression of several Vitamin D target genes such as the 24-hydroxylase, CD14, osteocalcin, and osteopontin in both cell lines, Ro3582 regulated many genes involved in cell proliferation and apoptosis, cell adhesion, invasion, angiogenesis as well as cell signaling pathways, such as the BMP and TGF-beta systems, differently in the two cell lines. The Gemini Vitamin D(3) analog Ro3582 induced more significant gene changes in the early premalignant MCF10AT1 cells than in the malignant metastatic MCF10CA1a cells, suggesting that Gemini Vitamin D(3) analogs may be more effective in preventing the progression of an early stage of breast carcinogenesis than in treating late stage breast cancer.
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Affiliation(s)
- Hong Jin Lee
- Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, 08854, USA
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Molnár F, Peräkylä M, Carlberg C. Vitamin D receptor agonists specifically modulate the volume of the ligand-binding pocket. J Biol Chem 2006; 281:10516-26. [PMID: 16478719 DOI: 10.1074/jbc.m513609200] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Existing crystal structure data has indicated that 1alpha,25-dihydroxyvitamin D(3) (1alpha,25(OH)(2) D(3)) and its analogues bind the ligand-binding pocket (LBP) of the human vitamin D receptor in a very similar fashion. Because docking of a ligand into the LBP is a more flexible process than crystallography can monitor, we analyzed 1alpha,25(OH)(2)D(3), its 20-epi derivative MC1288, the two side-chain analogues Gemini and Ro43-83582 (a hexafluoro-derivative) by molecular dynamics simulations in a complex with the vitamin D receptor ligand-binding domain and a co-activator peptide. Superimposition of the structures showed that the side chain of MC1288, the first side chain of the conformation II of Gemini, the second side chain of Ro43-83582 in conformation I and the first side chain of Ro43-83582 in conformation II take the same agonistic position as the side chain of 1alpha,25(OH)(2)D(3). Compared with the LBP of the natural hormone MC1288 reduced the volume by 17%, and Gemini expanded it by 19%. The shrinking of the LBP of MC1288 and its expansion to accommodate the second side chain of Gemini or Ro43-83582 is the combined result of minor movements of more than 30 residues and major movements of a few critical amino acids. The agonist-selective recognition of anchoring OH groups by the conformational flexible residues Ala-303, Leu-309, and His-397 was confirmed by in vitro assays. In summary, variations in the volume of agonists lead to adaptations in the volume of the LBP and alternative contacts of anchoring OH-groups.
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Affiliation(s)
- Ferdinand Molnár
- Department of Biochemistry, University of Kuopio, FIN-70211 Kuopio, Finland
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Posner GH, Jeon HB, Sarjeant A, Riccio ES, Doppalapudi RS, Kapetanovic IM, Saha U, Dolan P, Kensler TW. Low-calcemic, efficacious, 1alpha,25-dihydroxyvitamin D3 analog QW-1624F2-2: calcemic dose-response determination, preclinical genotoxicity testing, and revision of A-ring stereochemistry. Steroids 2004; 69:757-62. [PMID: 15579327 DOI: 10.1016/j.steroids.2004.09.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2004] [Revised: 09/27/2004] [Accepted: 09/29/2004] [Indexed: 11/17/2022]
Abstract
Based on an X-ray crystal structure determination, the A-ring stereochemistry of hybrid analog QW-1624F2-2 (1alpha-hydroxymethyl-16-ene-24,24-difluoro-25-hydroxy-26,27-bis-homovitamin D3) is revised to be 1alpha-CH2OH-3beta-OH. This analog is shown to be approximately 80-100 times less calciuric than the natural hormone 1alpha,25-dihydoxyvitamin D3. This analog is shown also to be non-genotoxic in three different standard assays.
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Affiliation(s)
- Gary H Posner
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA.
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Carlberg C. Ligand-mediated conformational changes of the VDR are required for gene transactivation. J Steroid Biochem Mol Biol 2004; 89-90:227-32. [PMID: 15225776 DOI: 10.1016/j.jsbmb.2004.03.112] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The central element of the molecular switch of nuclear 1alpha,25-dihydroxyvitamin D(3) (1alpha,25(OH)(2)D(3)) signaling is the ligand-binding domain (LBD) of the Vitamin D receptor (VDR), which can be stabilized by 1alpha,25(OH)(2)D(3) or its analogues in to agonistic, antagonistic or inverse agonistic conformations. The positioning of helix 12 of the LBD is of most critical importance for these conformations, because it determines the distance between the charge clamp amino acids K246 and E420 that are essential for VDR-coactivator (CoA) interaction. Most VDR ligands have been identified as agonists and only a few (e.g., ZK168281 and TEI-9647) as pure or partial antagonists. Antagonists induce corepressor (CoR) dissociation from the VDR but prevent completely or partially CoA interaction and thus transactivation. Gemini is a 1alpha,25(OH)(2)D(3) analogue with two identical side chains that despite its significantly increased volume binds to the VDR and acts under most conditions as an agonist. Interestingly, supramolar CoR concentrations shift Gemini from an agonist to an inverse agonist, which actively recruits CoR to the VDR and thus mediates repression of 1alpha,25(OH)(2)D(3) target genes. Gemini is the first described (conditional) inverse agonist to an endocrine nuclear receptor (NR) and may function as a sensor for cell-specific CoA/CoR ratios.
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Affiliation(s)
- Carsten Carlberg
- Department of Biochemistry, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland.
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Weyts FA, Dhawan P, Zhang X, Bishop JE, Uskokovic MR, Ji Y, Studzinski GP, Norman AW, Christakos S. Novel Gemini analogs of 1α,25-dihydroxyvitamin D3 with enhanced transcriptional activity. Biochem Pharmacol 2004; 67:1327-36. [PMID: 15013848 DOI: 10.1016/j.bcp.2003.12.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2003] [Accepted: 12/01/2003] [Indexed: 11/19/2022]
Abstract
The active form of vitamin D, 1alpha,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)), exerts its effects through regulation of target gene transcription. Configuration at C-20 of 1,25(OH)(2)D(3) is important in determining potency, as shown by the high potency of analogs with inverted configuration at C-20 (20-epi compounds). Gemini analogs of 1,25(OH)(2)D(3) contain two side chains, combining a C-20-normal with a C20-epi side chain. We studied the potency of analogs combining double (Gemini) side chains with a 23-triple bond and a C-26,27-hexafluoro substitution in either the 20-epi (analog 20R) or 20-normal (analog 20S) side chain. These novel Gemini analogs were 8-50-fold more potent than 1,25(OH)(2)D(3) in inducing U937, HL-60G, and THP-1 differentiation and 5-50-fold more potent in inducing transcription from the osteocalcin vitamin D response element or the 25-hydroxyvitamin D(3)-24-hydroxylase (24OHase) promoter. In vivo, following i.p. injection in vitamin D-deficient mice, the 20S analog induced significantly higher levels of calbindin-D(9K) mRNA in intestine, and 24OHase and calbindin-D(28K) in kidney than 1,25(OH)(2)D(3) or analog 20R. Increased potency did not correlate with ligand-receptor binding affinity. In GST-pull down assays using in vitro translated VDR, Gemini analogs showed equivalent (or even attenuated) potency to 1,25(OH)(2)D(3) in recruiting cofactors DRIP205 and GRIP-1 to VDR. However, Gemini analogs were up to 15-fold more potent than 1,25(OH)(2)D(3) in recruiting the same cofactors to VDR in GST-pull down assays using equal amounts of VDR from nuclear extracts of VDR transfected and hormone treated (24 hr) COS-7 cells. Deletion of C-19 in either 20S or 20R Gemini analogs resulted overall in slightly less potent analogs compared to Gemini itself. We conclude that enhanced potency of the novel Gemini analogs is at least partly due to increased metabolic stability of the analogs, resulting in more cofactor binding and elevated levels of transcription.
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Affiliation(s)
- Franci A Weyts
- Department of Biochemistry and Molecular Biology UMDNJ-New Jersey Medical School, Newark, NJ 07103, USA
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Schuster I, Egger H, Reddy GS, Vorisek G. Combination of vitamin D metabolites with selective inhibitors of vitamin D metabolism. Recent Results Cancer Res 2003; 164:169-88. [PMID: 12899522 DOI: 10.1007/978-3-642-55580-0_13] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
1alpha,25(OH)2D3 exerts antiproliferative, differentiating effects on many cell types, including cancer tissues. In most of its target cells, levels of 1alpha,25(OH)2D3 are regulated by local synthesis via CYP27B and metabolism via CYP24. Rapidly induced by vitamin D, CYP24 repeatedly hydroxylates the vitamin D side chain and ultimately terminates hormonal activity. Aiming at increased hormone levels, lifetime and function, numerous vitamin D analogs have been synthesized with structural modifications, which impede oxidation of the vitamin D side chain. Our group followed a different strategy, namely, blocking 1,25(OH)2D3 metabolism with inhibitors of CYP24. As appropriate inhibitors, we exploited compounds termed azoles, which directly bind to the heme iron of the CYPs via an azole nitrogen and to other parts of the substrate site. We synthesized some 400 azoles and tested their potential to selectively inhibit CYP24, but not hormone synthesis by the related CYP27B. Using primary human keratinocyte cultures as the source of CYP24 and CYP27, we discovered some 50 inhibitors of CYP24 with IC50 values in the nanomole range and selectivities up to 60-fold. As the first representative of selective CYP24 inhibitors, VID400 underwent preclinical development. In human keratinocytes, VID400 stabilized levels of endogenously produced 1alpha,25(OH)2D3, and thereby strongly amplified and prolonged expression of CYP24, a surrogate marker of hormonal function. In parallel, antiproliferative activity showed up at 100-fold or more lower concentrations of 1alpha,25(OH)2D3. This data suggests that CYP24 inhibitors could become attractive drugs in antiproliferative therapy, used as single entities to increase or extend endogenous hormone function or in combination with low doses of potent analogs. Moreover, we used selective inhibitors as valuable tools to (a) elucidate regulatory mechanisms of vitamin D synthesis and metabolism, (b) determine intrinsic activities of the otherwise highly transient vitamin D metabolites and (c) model the active sites of CYP24 and CYP27B.
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Affiliation(s)
- Inge Schuster
- Institute of Pharmaceutical Chemistry, University Vienna, Althanstrasse 15, 1090 Vienna, Austria.
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Carlberg C. Current understanding of the function of the nuclear vitamin D receptor in response to its natural and synthetic ligands. Recent Results Cancer Res 2003; 164:29-42. [PMID: 12899512 DOI: 10.1007/978-3-642-55580-0_2] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The vitamin D receptor (VDR), the high affinity receptor for 1alpha,25-dihydroxyvitamin D3 (1alpha,25(OH)2D3), is a member of the nuclear receptor superfamily. VDR preferentially forms a heterodimeric complex with the retinoid X receptor (RXR) and binds to 1alpha,25(OH)2D3 response elements (VDREs) that consist of two hexameric motifs in a directly repeated (DR) or inverted palindromic (IP) arrangement. DNA-complexed VDR acts as a molecular switch of nuclear 1alpha,25(OH)2D3 signaling by transmitting its activation status to different chromatin loci containing the 1alpha,25(OH)2D3 target genes. Approximately 0.5% of the human genome (about 200 genes) are estimated to be primary targets of 1alpha,25(OH)2D3, but via various mechanisms the VDR appears to interfere in the regulation of even more genes. The molecular basis of the regulatory actions of 1alpha,25(OH)2D3 and its synthetic analogs are ligand-triggered protein-protein interactions of the ligand-binding domain (LBD) of the VDR with coactivator (CoA), corepressor (CoR) and other nuclear proteins. Most analogs have been identified as agonists, a few as antagonists (ZK159222 and TEI-9647) and only Gemini and some of its variations as nonagonists. The positioning of helix 12 of the LBD is of critical importance for the agonistic, antagonistic and nonagonistic conformation of the VDR. In each of the three conformations, the VDR performs different protein-protein interactions, which then result in a characteristic functional profile. The functional profile of some 1alpha,25(OH)2D3 analogs, such as EB1089 and Gemini, can be modulated by protein and DNA interaction partners of the VDR. This provides them with some selectivity for DNA-dependent and -independent signaling pathways and VDRE structures.
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Affiliation(s)
- Carsten Carlberg
- Department of Biochemistry, University of Kuopio, P.O. Box 1627, 70211 Kuopio, Finland.
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Väisänen S, Peräkylä M, Kärkkäinen JI, Uskokovic MR, Carlberg C. Structural evaluation of the agonistic action of a vitamin D analog with two side chains binding to the nuclear vitamin D receptor. Mol Pharmacol 2003; 63:1230-7. [PMID: 12761332 DOI: 10.1124/mol.63.6.1230] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The vitamin D receptor (VDR) is one of the endocrine members of the nuclear receptor superfamily and has a characteristic high affinity for its natural ligand 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3]. From a mechanistic point of view, the most interesting analog of 1alpha,25(OH)2D3 is the one that carries two side chains, referred to as Gemini. In this study, molecular dynamics (MD) simulations of the Gemini-VDR complex were performed that demonstrated that the binding of a ligand with a 25% increased volume does not disturb the overall structure of the ligand-binding domain (LBD). It was found that one of the two side chains takes exactly the same position as the single side chain of the natural ligand, which suggests that the molecular mechanism of the agonism of Gemini is identical to that of 1alpha,25(OH)2D3. VDR single and double point mutants at L227, A303, I313, and L397 and in vitro and ex vivo assessment of their agonistic action confirmed the predictions of the MD simulations. Moreover, it was found that the second side chain of Gemini can choose between two binding positions within the ligand-binding pocket of the VDR. These two newly identified "corners" were characterized most specifically by the amino acids pairs L227/A303 and I313/L397. Therefore, Gemini is an important model compound that allows further insight into the molecular actions of the VDR but is, in parallel, also a promising precursor for the design of even more potent 1alpha,25(OH)2D3 analogs.
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Affiliation(s)
- Sami Väisänen
- Department of Biochemistry, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland
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Abstract
More than 2,000 synthetic analogues of the biological active form of vitamin D, 1alpha,25-dihydroxyvitamin D(3) (1alpha,25(OH)(2)D(3)), are presently known. Basically, all of them interfere with the molecular switch of nuclear 1alpha,25(OH)(2)D(3) signaling, which is the complex of the vitamin D receptor (VDR), the retinoid X receptor (RXR), and a 1alpha,25(OH)(2)D(3) response element (VDRE). Central element of this molecular switch is the ligand-binding domain (LBD) of the VDR, which can be stabilized by a 1alpha,25(OH)(2)D(3) analogue either in its agonistic, antagonistic, or non-agonistic conformation. The positioning of helix 12 of the LBD is of most critical importance for these conformations. In each of the three conformations, the VDR performs different protein-protein interactions, which then result in a characteristic functional profile. Most 1alpha,25(OH)(2)D(3) analogues have been identified as agonists, a few are antagonists (e.g., ZK159222 and TEI-9647), and only Gemini and some of its derivatives act under restricted conditions as non-agonists. The functional profile of some 1alpha,25(OH)(2)D(3) analogues, such as EB1089 and Gemini, can be modulated by protein and DNA interaction partners of the VDR. This provides them with some selectivity for DNA-dependent and -independent signaling pathways and VDRE structures.
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Affiliation(s)
- Carsten Carlberg
- Department of Biochemistry, University of Kuopio, FIN-70211 Kuopio, Finland.
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