RESUMO
The biologically active metabolite of vitamin D3 - calcitriol - is a hormone involved in the regulation of calcium-phosphate homeostasis, immunological processes and cell differentiation, being therefore essential for the proper functioning of the human body. This suggests many applications of this steroid in the treatment of diseases such as rickets, psoriasis and some cancers. Unfortunately, using therapeutic doses of calcitriol is associated with high concentrations of this compound which causes hypercalcemia. For this reason, new calcitriol analogs are constantly sought, devoid of calcemic effects but maintaining its beneficial properties. In this study, we present the synthesis of vitamin D derivatives characterized by an enlarged (seven-membered) ring D. Preparation of the designed vitamin D compounds required separate syntheses of crucial building blocks (C/D-rings fragments with side chain and rings A) which were combined by different methods, including Wittig-Horner reaction and Suzuki coupling. Biological activities of the target vitamin D analogs were assessed both in vitro and in vivo, demonstrating their significant potency compared to the natural hormone. Furthermore, the successful crystallization of these compounds with the vitamin D receptor (VDR) enabled us to investigate additional molecular interactions with this protein.
Assuntos
Desenho de Fármacos , Receptores de Calcitriol , Receptores de Calcitriol/metabolismo , Receptores de Calcitriol/agonistas , Humanos , Relação Estrutura-Atividade , Animais , Estrutura Molecular , Cristalografia por Raios X , Calcitriol/farmacologia , Calcitriol/química , Calcitriol/síntese química , Calcitriol/análogos & derivados , Camundongos , Relação Dose-Resposta a Droga , Modelos MolecularesRESUMO
Continuing our studies aimed at A-ring modified vitamin D compounds, we designed novel 19-norcalcitriol derivatives bearing at C-2 pegylated chains of different lengths. The terminal fragments of these substituents contain hydroxyls or moieties possessing nitrogen and/or sulfur atoms capable of transition metal ions complexation. Also, two conjugate-type platinum(II) complexes of 19-norcalcitriol were obtained in which l-methionine served as chelating moiety. The convergent synthesis of the target 19-norcalcitriol analogs involved several steps with the crucial one being condensation of A-ring phosphine oxide and the known Grundmann ketone by Wittig-Horner reaction. Further elaboration of the 2-alkylidene substituent provided all final compounds which were then tested to determine their affinity for the vitamin D receptor and cytotoxic activity.
Assuntos
Calcitriol/química , Calcitriol/farmacologia , Desenho de Fármacos , Antineoplásicos/farmacologia , Sítios de Ligação , Calcitriol/síntese química , Sobrevivência Celular/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Ensaios de Seleção de Medicamentos Antitumorais , Células HL-60 , Humanos , Ligantes , Células MCF-7 , Simulação de Acoplamento Molecular , Receptores de Calcitriol/efeitos dos fármacosRESUMO
Hormonally active vitamin D3 metabolite, calcitriol, plays an important role in calcium-phosphate homeostasis, immune system actions and cell differentiation. Although anticancer activity of calcitriol is well documented and thousands of its analogs have been synthesized, none has been approved as a potential drug against cancer. Therefore, we attempted to introduce the cytotoxic effect to the calcitriol molecule by its linking to cisplatin. Herein, we present the synthesis of vitamin D compounds, designed on the basis of molecular modeling and docking experiments to the vitamin D receptor, and characterized by the presence of significantly different two side chains attached to C-20. In this study, a new synthetic approach to Gemini analogs was developed. Preparation of the target 19-norcalcitriol compounds involved separate syntheses of several building blocks (the A-ring, C/D-rings and side-chain fragments). The convergent synthetic strategy was used to combine these components by the different coupling processes, the crucial one being Wittig-Horner reaction of the Grundmann ketone analog with the known 2-methylene A-ring phosphine oxide. Due to the nature of the constructed steroidal side chains (bidentate ligands), which allowed coordination of metal ions, the first conjugate-type platinum(II) complexes of the vitamin D analogs were also successfully prepared and characterized. The target vitamin D compounds, displaying significant affinity for a vitamin D receptor, were assessed in vitro for their anti-proliferative activities towards several cell lines.
Assuntos
Antineoplásicos/química , Calcitriol/análogos & derivados , Compostos Organoplatínicos/química , Vitaminas/química , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Calcitriol/síntese química , Calcitriol/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Técnicas de Química Sintética , Desenho de Fármacos , Humanos , Simulação de Acoplamento Molecular , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Compostos Organoplatínicos/síntese química , Compostos Organoplatínicos/farmacologia , Receptores de Calcitriol/metabolismo , Vitaminas/síntese química , Vitaminas/farmacologiaRESUMO
The active form of vitamin D3 , calcitriol, is a potent antiproliferative compound. However, when effective antitumor doses of calcitriol are used, hypercalcemic effects are observed, thus blocking its therapeutic application. To overcome this problem, structural analogues have been designed with the aim of retaining or even increasing the antitumor effects while decreasing its calcemic activity. This report aims at gaining insights into the structure-activity relationships of the novel oxolane-containing analogue, AM-27, recently synthesized. We herein demonstrate that this compound has antiproliferative and antimigratory effects in squamous cell carcinoma, glioblastoma, and breast cancer cell lines. Analyses of the mechanisms underlying the AM-27 effects on cell viability revealed induction of apoptosis by the analogue. Importantly, nonmalignant cell lines were little or not affected by the compound. In addition, the analogue did not produce hypercalcemia in mice. Also, in silico studies involving docking and molecular dynamics techniques showed that AM-27 is able to bind to the human vitamin D receptor with a higher affinity than the natural ligand calcitriol, a feature that is mostly derived from an electrostatic interaction pattern. Altogether, the proapoptotic effect observed in cancer cells, the lack of calcemic activity in mice, and the differential effects in normal cells suggest the potential of AM-27 as a therapeutic compound for cancer treatment.
Assuntos
Antineoplásicos/farmacologia , Calcitriol/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Calcitriol/síntese química , Calcitriol/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Simulação por Computador , Relação Dose-Resposta a Droga , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
Calcitriol analogs have shown promising potential as compounds to be used in cancer chemotherapy. This report presents the synthesis of a novel vitamin D3 derivative with an amide and a carboxyl group in its side chain, called ML-344. In addition, we report its in vitro antitumor activity and its in vivo calcemic effects. We demonstrate that the analog decreases cell viability and retards cell migration of different breast, glioblastoma and head and neck cancer cell lines. Additionally, unlike calcitriol, ML-344 does not display citotoxicity to the murine non-malignant mammary cells and human astrocytes. In concordance with the antimigratory effects found in breast cancer cells, ML-344 decreased the invasive capacity and induced a rearrangement of the actin cytoskeleton in the LM3 breast cancer cell line. In relation to the in vivo studies, the analog did not cause hypercalcemic effects in CF1 mice administered daily at 5 µg/Kg of body weight during a period of 264 h. Finally, computational studies were performed to evaluate the potential binding of the analog to the vitamin D receptor and the in silico assays showed that ML-344 is able to bind to VDR with interesting particularities and greater affinity than calcitriol. Altogether, these results suggest that ML-344 has a promising potential as an antitumor agent with a differential effect between tumor and non-malignant cells.
Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Calcitriol/análogos & derivados , Calcitriol/farmacologia , Glioblastoma/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Receptores de Calcitriol/metabolismo , Animais , Antineoplásicos/síntese química , Astrócitos/efeitos dos fármacos , Calcitriol/síntese química , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Masculino , CamundongosRESUMO
Previously, we found that 2α-[2-(tetrazol-2-yl)ethyl]-1α,25-dihydroxyvitamin D3 (AH-1) showed higher osteocalcin promoter transactivation activity in human osteosarcoma (HOS) cells and a greater therapeutic effect on ovariectomized (OVX) rats for enhancing bone mineral density than those of 1α,25(OH)2D3 without hypercalcemic side effects in vivo. Although CYP24A1 catalyzes multi-step oxidations toward the CD-ring side chain of the active vitamin D3 [1α,25(OH)2D3], the CYP24A1-dependent metabolism of AH-1 tended to stop at the first step hydroxylation at the C24-position of AH-1. Interestingly, the metabolite 24-hydroxy-AH-1 [24(OH)AH-1] showed potent VDR binding affinity, and the new chiral center of the 24-position might be the 24R configuration compared with the process of the natural 1α,25(OH)2D3 catabolism. This time, (24R)-2α-[2-(tetrazol-2-yl)ethyl]-1α,24,25-trihydroxyvitamin D3 [(24R-OH)AH-1] was synthesized as a candidate for the major metabolite of AH-1 using the Trost Pd-mediated coupling reaction between A-ring and CD-ring precursors to identify the metabolite and evaluate its biological activity. We confirmed that the CYP24A1-dependent major metabolite of AH-1 was (24R-OH)AH-1 by HPLC analyses.
Assuntos
Calcitriol/síntese química , Calcitriol/metabolismo , Técnicas de Química Sintética , Vitamina D3 24-Hidroxilase/metabolismo , Vitaminas/síntese química , Vitaminas/metabolismo , Animais , Calcitriol/análogos & derivados , Catálise , Técnicas de Química Sintética/métodos , Paládio/química , Ratos , Proteínas Recombinantes/metabolismo , Estereoisomerismo , Vitaminas/químicaRESUMO
A systematic study with phase 1 and phase 2 metabolites of cholesterol and vitamin D was conducted to determine whether their biological activity is mediated by the vitamin D receptor (VDR). The investigation necessitated the development of novel synthetic routes for lithocholic acid (LCA) glucuronides (Gluc). Biochemical and cell-based assays were used to demonstrate that hydroxylated LCA analogs were not able to bind VDR. This excludes VDR from mediating their biological and pharmacological activities. Among the synthesized LCA conjugates a novel VDR agonist was identified. LCA Gluc II increased the expression of CYP24A1 in DU145 cancer cells especially in the presence of the endogenous VDR ligand 1,25(OH)2D3. Furthermore, the methyl ester of LCA was identified as novel VDR antagonist. For the first time, we showed that calcitroic acid, the assumed inactive final metabolite of vitamin D, was able to activate VDR-mediated transcription to a higher magnitude than bile acid LCA. Due to a higher metabolic stability in comparison to vitamin D, a very low toxicity, and high concentration in bile and intestine, calcitroic acid is likely to be an important mediator of the protective vitamin D properties against colon cancer.
Assuntos
Calcitriol/análogos & derivados , Colesterol/metabolismo , Glucuronatos/farmacologia , Ácido Litocólico/farmacologia , Receptores de Calcitriol/metabolismo , Transcrição Gênica/efeitos dos fármacos , Vitamina D/metabolismo , Calcitriol/síntese química , Calcitriol/química , Calcitriol/farmacologia , Linhagem Celular Tumoral , Glucuronatos/síntese química , Glucuronatos/química , Humanos , Ácido Litocólico/síntese química , Ácido Litocólico/química , Masculino , Neoplasias da Próstata/metabolismo , Receptores de Calcitriol/agonistas , Vitamina D3 24-Hidroxilase/metabolismoRESUMO
Recently, we found that 2α-[2-(tetrazol-2-yl)ethyl]-1α,25-dihydroxyvitamin D3 showed higher osteocalcin promoter transactivation activity in human osteosarcoma (HOS) cells and a greater therapeutic effect in ovariectomized (OVX) rats in vivo than those of active vitamin D3, 1α,25(OH)2D3. We were interested in introducing a heterocyclic ring to the C2 position of the seco-steroidal structure via an alkyl linker, and four novel C2-(3-tetrazolylpropyl) substituted 1α,25-dihydroxy-19-norvitamin D3 analogs, 2α-[3-(tetrazol-1-yl)propyl]-, 2ß-[3-(tetrazol-1-yl)propyl]-, 2α-[3-(tetrazol-2-yl)propyl]-, and 2ß-[3-(tetrazol-2-yl)propyl]-19-nor-1α,25(OH)2D3 were synthesized. Among them, 2α-[3-(tetrazol-1-yl)propyl]-19-nor-1α,25(OH)2D3 showed weak binding affinity for human vitamin D receptor (hVDR) (2.6% of 1α,25(OH)2D3 and ca. 15% of 19-nor-1α,25(OH)2D3) and weak VDR transactivation activity in HOS cells (EC50 7.3nM, when 1α,25(OH)2D30.23nM). Although the other three compounds could not act as VDR binders by evaluation of the competition assays, 2α-[3-(tetrazol-2-yl)propyl]-19-nor-1α,25(OH)2D3 showed weak transactivation activity (EC50 12.5nM). Metabolic stability of the 2α-substituted compounds 2α-[3-(tetrazol-1-yl)propyl]- and 2α-[3-(tetrazol-2-yl)propyl]-19-nor-1α,25(OH)2D3 was higher than that of the 2ß-substituted counterparts 2ß-[3-(tetrazol-1-yl)propyl]- and 2ß-[3-(tetrazol-2-yl)propyl]-19-nor-1α,25(OH)2D3 against human CYP24A1. Introduction of a tetrazole ring to the C2-position of the 19-norvitamin D3 skeleton with the propyl linker led to weak VDR agonistic activity with stability against CYP24A1 metabolism.
Assuntos
Calcitriol/análogos & derivados , Osteossarcoma/metabolismo , Tetrazóis/síntese química , Animais , Calcitriol/síntese química , Calcitriol/química , Cromatografia Líquida de Alta Pressão , Desenho de Fármacos , Etilenos/química , Humanos , Osteocalcina/genética , Osteoporose/tratamento farmacológico , Ovariectomia , Regiões Promotoras Genéticas , Ligação Proteica , Receptores de Calcitriol/genética , Proteínas Recombinantes/química , Tetrazóis/química , Ativação Transcricional , Vitamina D3 24-Hidroxilase/genéticaRESUMO
Four side chain fluorinated analogues of 1α,25-dihydroxy-19-norvitamin D have been prepared in convergent syntheses using the Wittig-Horner reaction as a key step. Structures and absolute configurations of analogues 3 and 5 were confirmed by X-ray crystallography. All analogues showed high potency in HL-60 cell differentiation and vitamin D-24-hydroxylase (24-OHase) transcription as compared to 1α,25-dihydroxyvitamin D3 (1). Most important is that all of the 20S-configured derivatives (4 and 6) had high bone mobilizing activity in vivo. However, in the 20R series, a 2-methylene group was required for high bone mobilizing activity. A change in positioning of the 20R molecule in the vitamin D receptor when the 2-methylene group is present may provide new insight into the molecular basis of bone calcium mobilization induced by vitamin D.
Assuntos
Osso e Ossos/efeitos dos fármacos , Calcitriol/análogos & derivados , Cálcio/metabolismo , Animais , Osso e Ossos/metabolismo , Calcitriol/síntese química , Calcitriol/química , Calcitriol/farmacologia , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Cristalografia por Raios X , Humanos , Masculino , Conformação Molecular , Simulação de Acoplamento Molecular , Ratos , Ratos Sprague-Dawley , Receptores de Calcitriol/metabolismo , Estereoisomerismo , Relação Estrutura-Atividade , Transcrição Gênica , Vitamina D3 24-Hidroxilase/genética , Vitamina D3 24-Hidroxilase/metabolismoRESUMO
In an attempt to prepare vitamin D analogues that are superagonists, (20R)- and (20S)-isomers of 1α-hydroxy-2-methylenevitamin D3 and 1α,25-dihydroxy-2-methylenevitamin D3 have been synthesized. To prepare the desired A-ring dienyne fragment, two different approaches were used, both starting from the (-)-quinic acid. The obtained derivative was subsequently coupled with the C,D-ring enol triflates derived from the corresponding Grundmann ketones, using the Sonogashira reaction. Moreover, (20R)- and (20S)-1α,25-dihydroxy-2-methylenevitamin D3 compounds with an (5E)-configuration were prepared by iodine catalyzed isomerization. All four 2-methylene analogues of the native hormone were characterized by high in vitro activity. As expected, the 25-desoxy analogues were much less potent. Among the synthesized compounds, two of them, 1α,25-dihydroxy-2-methylenevitamin D3 and its C-20 epimer, were found to be almost as active as 2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D3 (2MD) on bone but more active in intestine.
Assuntos
Calcitriol/análogos & derivados , Di-Hidroxicolecalciferóis/química , Receptores de Calcitriol/antagonistas & inibidores , Animais , Ligação Competitiva , Transporte Biológico , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Calcitriol/síntese química , Calcitriol/química , Calcitriol/farmacologia , Cálcio/metabolismo , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Di-Hidroxicolecalciferóis/síntese química , Di-Hidroxicolecalciferóis/farmacologia , Células Precursoras de Granulócitos/citologia , Células Precursoras de Granulócitos/efeitos dos fármacos , Humanos , Mucosa Intestinal/metabolismo , Intestinos/efeitos dos fármacos , Masculino , Modelos Moleculares , Células Musculares/citologia , Células Musculares/efeitos dos fármacos , Ratos Sprague-Dawley , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
We have synthesized 39 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] analogs having two side chains attached to carbon-20 (Gemini) with various modifications and compared their anticancer activities. Five structure-function rules emerged to identify analogs with enhanced anticancer activity. One of these active analogs, BXL-01-0126, was more potent than 1,25(OH)2D3 in mediating 50% clonal inhibition of cancer cell growth. Murine studies found that BXL-01-0126 and 1,25(OH)2D3 had nearly the same potency to raise serum calcium levels. Taken together, BXL-01-0126 when compared to 1,25(OH)2D3 has greater anticancer potency, but similar toxicity causing hypercalcemia. We focused on the effect of these compounds on the stimulation of expression of human cathelicidin antimicrobial peptide (CAMP) whose gene has a vitamin D response element in its promoter. Expression of CAMP mRNA and protein increased in a dose-response fashion after exposure of acute myeloid leukemia (AML) cells to the Gemini analog, BXL-01-126, in vitro. A xenograft model of AML was developed using U937 AML cells injected into NSG-immunodeficient mice. Administration of vitamin D3 compounds to these mice resulted in substantial levels of CAMP in the systemic circulation. This suggests a unique prophylactic treatment at diagnosis or during induction chemotherapy for AML patients to provide them with protection against various microbial infections through CAMP induction.
Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Calcitriol/análogos & derivados , Catelicidinas/biossíntese , Colecalciferol/farmacologia , Animais , Peptídeos Catiônicos Antimicrobianos , Antineoplásicos/química , Calcitriol/síntese química , Calcitriol/química , Calcitriol/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Colecalciferol/análogos & derivados , Colecalciferol/síntese química , Citometria de Fluxo , Xenoenxertos , Humanos , Camundongos , Reação em Cadeia da Polimerase em Tempo Real , Relação Estrutura-AtividadeRESUMO
X-ray cocrystallographic studies of the human vitamin D receptor (hVDR)-[2α-(3-hydroxypropyl)-1α,25-dihydroxyvitamin D3 (O1C3)] complex showed that the terminal hydroxy group of the 2α-functional group of O1C3 formed a hydrogen bond with Arg274 in the ligand binding domain (LBD) of hVDR to stabilize the complex; therefore, O1C3 showed 3-times greater binding affinity for VDR than the natural hormone. Here, the effects of a heteroaromatic ring on binding to hVDR instead of the terminal OH group of O1C3 and also on preliminary biological activities were studied. We synthesized 2α-[2-(tetrazol-2-yl)ethyl]-1α,25(OH)2D3 (1a) and its regioisomer 2α-[2-(tetrazol-1-yl)ethyl]-1α,25(OH)2D3 (1b), in which 1a showed much higher hVDR binding affinity and greater osteocalcin promoter transactivation activity in human osteosarcoma (HOS) cells than those of 1b. X-ray cocrystallographic analysis of the hVDR-1a complex showed new hydrogen bond formation between one of the nitrogen atoms of the tetrazole ring and Arg274. This article is part of a Special Issue entitled '16th Vitamin D Workshop'.
Assuntos
Antineoplásicos/síntese química , Calcitriol/análogos & derivados , Desenho de Fármacos , Receptores de Calcitriol/metabolismo , Vitaminas/síntese química , Antineoplásicos/farmacologia , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/patologia , Calcitriol/síntese química , Calcitriol/farmacologia , Humanos , Osteossarcoma/tratamento farmacológico , Osteossarcoma/metabolismo , Osteossarcoma/patologia , Relação Estrutura-Atividade , Vitaminas/farmacologiaRESUMO
One of the most innovative approaches to the treatment of cancer entails the use of 1α,25-dihydroxyvitamin D3 (calcitriol) analogs to inhibit cancer cell growth. We demonstrate here that BGP-13, a new calcipotriene-based 1α,25-dihydroxyvitamin D3 analog that we synthesized in our laboratory, inhibits the growth of prostate cancer (LNCaP), breast cancer (MCF-7), and colon cancer (HT-29) cell lines. Moreover, we also show that BGP-13 causes cells both to accumulate in G0-G1 and to activate caspase-3 and undergo apoptosis. In addition, we observed elevated vitamin D receptor (VDR) mRNA and protein levels in both LNCaP and MCF-7 cells following the exposure of the two cell lines to BGP-13. Importantly, we found that both the new analog BGP-13 and also BGP-15, another calcipotriene-based analog we synthesized previously and about which we published recently, inhibit the growth of HT-29 tumor xenografts in nude mice.
Assuntos
Apoptose/efeitos dos fármacos , Neoplasias da Mama/patologia , Calcitriol/análogos & derivados , Proliferação de Células/efeitos dos fármacos , Dioxóis/farmacologia , Neoplasias da Próstata/patologia , Animais , Western Blotting , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Calcitriol/síntese química , Calcitriol/farmacologia , Ciclo Celular/efeitos dos fármacos , Dioxóis/síntese química , Feminino , Células HT29 , Humanos , Técnicas In Vitro , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Estrutura Molecular , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/metabolismo , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais CultivadasRESUMO
1,25-dihydroxyvitamin D(3) has quite significant anticancer properties, but its strong calcemic effect in principle excludes it as a potential anticancer drug. Currently, a lot of effort is being devoted to develop potent anticancer analogs of 1,25-dihydroxyvitamin D(3) that would not induce hypercalcemia during therapy. In this work, the free binding energy of the VDR receptor with 1,25-dihydroxyvitamin D(3) and its three potent analogs (EB 1089, KH 1060 and RO 25-9022) is calculated and compared with each other. With this approach, we could estimate the relative binding affinity of the most potent analog, RO 25-9022, and also revealed a quite distinct mechanism of its interaction with VDR.
Assuntos
Antineoplásicos , Calcitriol , Conformação Proteica , Receptores de Calcitriol/química , Antineoplásicos/química , Antineoplásicos/farmacologia , Sítios de Ligação , Calcitriol/análogos & derivados , Calcitriol/síntese química , Calcitriol/química , Linhagem Celular Tumoral , Cristalografia por Raios X , Metabolismo Energético , Humanos , Hipercalcemia/induzido quimicamente , Hipercalcemia/complicações , Ligantes , Simulação de Acoplamento Molecular , Neoplasias/tratamento farmacológico , Ligação Proteica , Receptores de Calcitriol/metabolismoRESUMO
Structure-guided optimization was used to design new analogues of 1α,25-dihydroxyvitamin D3 bearing the main side chain at C12 and a shorter second hydroxylated chain at C17. The new compounds 5a-c were efficiently synthesized from ketone 9 (which is readily accessible from the Inhoffen-Lythgoe diol) with overall yields of 15%, 6%, and 3% for 5a, 5b, and 5c, respectively. The triene system was introduced by the Pd-catalyzed tandem cyclization-Suzuki coupling method. The new analogues were assayed against human colon and breast cancer cell lines and in mice. All new vitamin D3 analogues bound less strongly to the VDR than 1α,25-dihydroxyvitamin D3 but had similar antiproliferative, pro-differentiating, and transcriptional activity as the native hormone. In vivo, the three analogues had markedly low calcemic effects.
Assuntos
Calcitriol/análogos & derivados , Calcitriol/síntese química , Animais , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Caderinas/metabolismo , Calcitriol/farmacologia , Cálcio/sangue , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cistatinas/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Camundongos , Simulação de Acoplamento Molecular , Receptores de Calcitriol/metabolismo , Relação Estrutura-Atividade , Transcrição Gênica/efeitos dos fármacosRESUMO
An improved synthetic route to 1α,25-dihydroxyvitamin D(3) des-side chain analogues 2 a and 2 b with substituents at C18 is reported, along with their biological activity. These analogues display significant antiproliferative effects toward MCF-7 breast cancer cells and prodifferentiation activity toward SW480-ADH colon cancer cells; they are also characterized by a greatly decreased calcemic profile. The crystal structure of the human vitaminâ D receptor (hVDR) complexed to one of these analogues, 20(17â18)-abeo-1α,25-dihydroxy-22-homo-21-norvitamin D(3) (2 a) reveals that the side chain introduced at position C18 adopts the same orientation in the ligand binding pocket as the side chain of 1α,25-dihydroxyvitamin D(3).
Assuntos
Calcitriol/química , Animais , Sítios de Ligação , Calcitriol/síntese química , Calcitriol/farmacologia , Linhagem Celular Tumoral , Simulação por Computador , Humanos , Receptores de Calcitriol/química , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo , SuínosRESUMO
Synthesis of 1α,25-dihydroxyvitamin D(3)-3ß-bromoacetate (1,25(OH)(2)D(3)-3-BE), a potential anti-cancer agent is presented. We also report that mechanism of action of 1,25(OH)(2)D(3)-3-BE may involve reduction of its catabolism, as evidenced by the reduced and delayed expression of 1α,25-dihydroxyvitamin D(3)-24-hydroxylase (CYP24) gene in cellular assays.
Assuntos
Antibacterianos/química , Antineoplásicos/química , Calcitriol/análogos & derivados , Neoplasias/tratamento farmacológico , Antibacterianos/síntese química , Antibacterianos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/uso terapêutico , Calcitriol/síntese química , Calcitriol/química , Calcitriol/uso terapêutico , Linhagem Celular Tumoral , Escherichia coli/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Salmonella typhi/efeitos dos fármacos , Esteroide Hidroxilases/química , Esteroide Hidroxilases/metabolismo , Vitamina D3 24-HidroxilaseRESUMO
Vitamin D receptor (VDR) antagonists have therapeutic potential in treatment of allergic conditions and hypercalcemia driven by granulomatous diseases. We have identified an o-aminoanilide analogue of the hormonal form of vitamin D with a dienyl side chain that functions as a strong VDR antagonist. Modeling studies indicate that antagonism arises from side chain rigidity, when compared to a more flexible saturated analogue, which interferes with H12 folding/alignment.
Assuntos
Anilidas/síntese química , Calcitriol/análogos & derivados , Calcitriol/síntese química , Receptores de Calcitriol/antagonistas & inibidores , Anilidas/farmacologia , Ligação Competitiva , Calcitriol/farmacologia , Linhagem Celular Tumoral , Citocinas/biossíntese , Polarização de Fluorescência , Humanos , Modelos Moleculares , Receptores de Calcitriol/agonistas , Estereoisomerismo , Esteroide Hidroxilases/biossíntese , Relação Estrutura-Atividade , Vitamina D3 24-Hidroxilase , Linfopoietina do Estroma do TimoRESUMO
Calcitriol is implicated in many cellular functions including cellular growth and differentiation, thus explaining its antitumor effects. It was shown that gemini, the calcitriol derivative containing two side chain at C20, is also active in gene transcription with enhanced antitumor activity. We have now further optimized both the A-ring and the two side chains. The chemical structures of the resulting 18 geminis were correlated with biological activities. Those containing the 1alpha-fluoro A-ring are the least active. Those featuring 23-yne and 23(E) side-chains are generally more active in human breast cancer cell growth inhibition and human leukemia cell differentiation induction than their 23(Z) counterparts. On the basis of these evaluations, we selected as lead compound a 20(R) gemini, related to calcitriol in terms of it is A-ring, where one side chain was modified by introduction of a 23-yne function and replacement of the geminal methyl groups with trifluoromethyl groups, the other created by extension of C21 with a 3-hydroxy-3-trideuteromethyl-4,4,4-trideutero-butyl moiety.
Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Neoplasias da Mama/patologia , Calcitriol/análogos & derivados , Calcitriol/farmacologia , Diferenciação Celular/efeitos dos fármacos , Leucemia/patologia , Animais , Antineoplásicos/síntese química , Calcitriol/síntese química , Linhagem Celular Tumoral , Humanos , Concentração Inibidora 50 , Camundongos , Modelos Moleculares , Conformação MolecularRESUMO
The active vitamin D3, 1alpha,25-dihydroxyvitamin D3 (1,25(OH)2D3), is now well recognized as a potent regulator of cell proliferation and differentiation in addition to possessing a regulatory effect on calcium and phosphorus metabolism. From research on the synthesis of 1,25(OH)2D3 analogs with the goal of separating these biological activities, we have already reported two characteristic analogs of active vitamin D3, namely 1alpha,25-dihydroxy-22-oxavitamin D3 (OCT) and 1alpha,25-dihydroxy-2beta-(3-hydroxypropoxy) vitamin D3 (ED-71). OCT, a 22-oxa analog obtained from modification of the side chain of 1,25(OH)2D3, has been used clinically as an injection for the treatment of secondary hyperparathyroidism underlying renal insufficiency and as an ointment for the skin disease, psoriasis. OCT has also been reported to exhibit antiangiogenic activity, exerting antitumor effects without producing serious side effects such as hypercalcemia. On the other hand, ED-71, which possesses a hydroxypropoxy substituent at the 2beta-position of the A-ring of 1,25(OH)2D3, has more potent biological effects on bone compared to 1 and phase III clinical studies for bone-fracture prevention have been completed. To explore structure activity relationship between ED-71 and related analogs, significant attention was now focused on the diastereomer of 3 at both the 1- and 3-positions of the A-ring, namely 3-epi-ED-71, 1-epi-ED-71 and 1,3-diepi-ED-71. All possible A-ring diastereomers at the 1- and 3-positions of ED-71 were synthesized using C2-symmetrical epoxide as a common starting material by convergent Trost methodology.