RESUMEN
The tubulin-microtubule system is a major target for a variety of small molecules which can interfere in cell cycle progression. Therefore, it serves as a prospective to control the incessant division of cancer cells. To identify novel inhibitors of the tubulin-microtubule system, a group of estrogen derivatives has been tested with tubulin as a target since literature surveys portray coveted behaviour from the same. Out of them, ß-Estradiol-6-one 6- (O-carboxy methyl Oxime) abbreviated as Oxime, disrupts the cytoskeleton network and induces apoptosis with nuclei fragmentation. It has been revealed from the work that Oxime targets the colchicine binding site and binds tubulin in an entropy-driven manner. This suggests that structural variation might play a key role in modulating the anti-mitotic role of estrogen derivatives. Our work reveals that Oxime might serve as a lead molecule to nurture anti-cancer research, having the potential for recovery of the vast cancer population.
Asunto(s)
Antimitóticos , Antineoplásicos , Tubulina (Proteína)/química , Antimitóticos/metabolismo , Moduladores de Tubulina/farmacología , Moduladores de Tubulina/química , Moduladores de Tubulina/metabolismo , Mitosis , Estudios Prospectivos , Microtúbulos/metabolismo , Estradiol/farmacología , Estradiol/metabolismo , Sitios de Unión , Estrógenos/metabolismo , Antineoplásicos/farmacología , Antineoplásicos/metabolismoRESUMEN
The cytoprotective effects of a novel hydroalcoholic extract (0.01-5 mg/mL) from Lens culinaria (Terre di Altamura Srl) were investigated within murine native skeletal muscle fibers, bone marrow cells, and osteoblasts, and in cell lines treated with the apoptotic agent staurosporine (2.14 × 10-6 M), the alkylating drug cisplatin (10-4 M), the topoisomerase I inhibitor irinotecan (10-4 M), the antimitotic pro-oxidant doxorubicin (10-6 M), and the immunosuppressant dexamethasone (2 × 10-6 M). An amount of 10g of plant material was used to obtain a 70% ethanol/water product, following two-step extraction, evaporation, lyophilization, and storage at -20 °C. For the murine osteoblasts, doxorubicin reduced survival by -65%, dexamethasone by -32% and -60% after 24 and 48 h of incubation time, respectively. The extract was effective in preventing the osteoblast count-reduction induced by dexamethasone; it was also effective at preventing the inhibition of mineralization induced by dexamethasone. Doxorubicin and cisplatin caused a significant reduction in cell growth by -77% for bone marrow cells, -43% for irinotecan, and -60% for dexamethasone, but there was no evidence for the cytoprotective effects of the extract in these cells. Staurosporine and doxorubicin caused a fiber death rate of >-40% after 18 and 24 h of incubation, yet the extract was not effective at preventing these effects. The extract was effective in preventing the staurosporine-induced reduction of HEK293 proliferation and colony formation in the crystal violet DNA staining and the clonogenic assays. It was also effective for the cisplatin-induced reduction in HEK293 cell proliferation. The extract, however, failed to protect the SHSY5Y neurons against cisplatin and irinotecan-induced cytotoxicity. A UV/VIS spectroscopy analysis showed three peaks at the wavelengths of 350, 260, and 190 nm, which correspond to flavonoids, proanthocyanins, salicylates, and AA, constituting the extract. These data suggest the possible development of this extract for use against dexamethasone-induced bone loss and renal chemotherapy-induced damage.
Asunto(s)
Antimitóticos , Dexametasona , Animales , Antimitóticos/metabolismo , Antimitóticos/farmacología , Cisplatino/metabolismo , Cisplatino/farmacología , Dexametasona/farmacología , Doxorrubicina/farmacología , Etanol/farmacología , Flavonoides/farmacología , Violeta de Genciana/metabolismo , Violeta de Genciana/farmacología , Células HEK293 , Humanos , Inmunosupresores/farmacología , Irinotecán/farmacología , Ratones , Osteoblastos/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Salicilatos/metabolismo , Salicilatos/farmacología , Estaurosporina/farmacología , Inhibidores de Topoisomerasa I/metabolismo , Inhibidores de Topoisomerasa I/farmacología , Agua/metabolismoRESUMEN
The fungus Rhizopus microsporus harbors a bacterial endosymbiont (Mycetohabitans rhizoxinica) for the production of the antimitotic toxin rhizoxin. Although rhizoxin is the causative agent of rice seedling blight, the toxinogenic bacterial-fungal alliance is, not restricted to the plant disease. It has been detected in numerous environmental isolates from geographically distinct sites covering all five continents, thus raising questions regarding the ecological role of rhizoxin beyond rice seedling blight. Here, we show that rhizoxin serves the fungal host in fending off protozoan and metazoan predators. Fluorescence microscopy and coculture experiments with the fungivorous amoeba Protostelium aurantium revealed that ingestion of R. microsporus spores is toxic to P. aurantium. This amoebicidal effect is caused by the dominant bacterial rhizoxin congener rhizoxin S2, which is also lethal toward the model nematode Caenorhabditis elegans. By combining stereomicroscopy, automated image analysis, and quantification of nematode movement, we show that the fungivorous nematode Aphelenchus avenae actively feeds on R. microsporus that is lacking endosymbionts, whereas worms coincubated with symbiotic R. microsporus are significantly less lively. This study uncovers an unexpected ecological role of rhizoxin as shield against micropredators. This finding suggests that predators may function as an evolutionary driving force to maintain toxin-producing endosymbionts in nonpathogenic fungi. IMPORTANCE The soil community is a complex system characterized by predator-prey interactions. Fungi have developed effective strategies to defend themselves against predators. Understanding these strategies is of critical importance for ecology, medicine, and biotechnology. In this study, we shed light on the defense mechanisms of the phytopathogenic Rhizopus-Mycetohabitans symbiosis that has spread worldwide. We report an unexpected role of rhizoxin, a secondary metabolite produced by the bacterium M. rhizoxinica residing within the hyphae of R. microsporus. We show that this bacterial secondary metabolite is utilized by the fungal host to successfully fend off fungivorous protozoan and metazoan predators and thus identified a fundamentally new function of this infamous cytotoxic compound. This endosymbiont-dependent predator defense illustrates an unusual strategy employed by fungi that has broader implications, since it may serve as a model for understanding how animal predation acts as an evolutionary driving force to maintain endosymbionts in nonpathogenic fungi.
Asunto(s)
Antimitóticos , Burkholderia , Oryza , Toxinas Biológicas , Animales , Burkholderia/metabolismo , Antimitóticos/metabolismo , Macrólidos , Simbiosis , Oryza/microbiología , Plantones , SueloRESUMEN
Vateria indica is persistent tree used in Unani sources for the medication and classified as critically endangered. Thus, endophytes for alternative methods to explore these endangered Plants having rich source pharmaceuticals' active molecules for drug development and production. Endophytes comprises unexplored microbes as a potential source of rich pharmaceutically bioactive compounds attributable to their relationship with the host. In the current study, we have isolated endophyte fungi Cladosporium from the plant Vateria indica and performed phytochemical screening of its ethanolic extract to detect the phytochemicals using thin layer chromatography (TLC), gas chromatography-mass spectrometry (GC-MS), high-performance liquid chromatography (HPLC), UV-visible spectrophotometry (UV-VIS), and Fourier transform infrared spectroscopy (FTIR). GC-MS analysis revealed the presence of an anticancer compound hydroxymethyl colchicine, antioxidant compound benzoic acid, and antimicrobial 2-(4-chlorophenoxy)-5-nitro in endophyte fungal extract of plant Vateria indica. Moreover, in silico analysis of bioactive compounds identified by GC-MS analysis using the Autodock Vina and SwissADME confirmed excellent anticancer activity methanone, [4-amino-2-[(phenylmethyl) amino]-5-thiazolyl] (4-fluorophenyl)- and hydroxymethyl colchicine against 6VO4 (Bfl-1 protein) as per Lipinski rule. Furthermore, we also demonstrated the excellent antioxidant of endophytic extract compared to plant extract by DPPH and ABTS assay, as well as antimicrobial activity against both Gram (+ ve) and Gram (- ve) bacteria. Moreover, the endophytic extract also showed its antimitotic activity with a mitotic index of 65.32, greater than the plant extract of 32.56 at 10 mg/ml. Thus endophytic fungi Cladosporium species isolated from plant Vateria indica might be used as a potential source for phytochemical anticancer hydroxymethyl colchicine, an antioxidant benzoic acid, and antimicrobial 2-(4-chlorophenoxy)-5-nitro.
Asunto(s)
Antiinfecciosos , Antimitóticos , Dipterocarpaceae , Antibacterianos , Antiinfecciosos/metabolismo , Antimitóticos/metabolismo , Antioxidantes/metabolismo , Antioxidantes/farmacología , Ácido Benzoico/metabolismo , Cladosporium , Colchicina/metabolismo , Endófitos , Metilcelulosa/metabolismo , Fitoquímicos/metabolismo , Fitoquímicos/farmacología , Extractos Vegetales/metabolismo , Extractos Vegetales/farmacología , PlantasRESUMEN
Antimitotic agents such as the clinically approved vinca alkaloids, taxanes and epothilone can arrest cell growth during interphase and are therefore among the most important drugs available for treating cancer. These agents suppress microtubule dynamics and thus interfere with intracellular transport, inhibit cell proliferation and promote cell death. Because these drugs target biological processes that are essential to all cells, they face an additional challenge when compared to most other drug classes. General toxicity can limit the applicable dose and therefore reduce therapeutic benefits. Photopharmacology aims to avoid these side-effects by introducing compounds that can be applied globally to cells in their inactive form, then be selectively induced to bioactivity in targeted cells or tissue during a defined time window. This review discusses photoswitchable analogues of antimitotic agents that have been developed by combining different photoswitchable motifs with microtubule-stabilizing or microtubule-destabilizing agents.
Asunto(s)
Antimitóticos , Antineoplásicos , Neoplasias , Alcaloides de la Vinca , Antimitóticos/metabolismo , Antimitóticos/farmacología , Antimitóticos/uso terapéutico , Antineoplásicos/metabolismo , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Humanos , Microtúbulos/metabolismo , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Alcaloides de la Vinca/metabolismo , Alcaloides de la Vinca/farmacología , Alcaloides de la Vinca/uso terapéuticoRESUMEN
We report the first cellular application of the emerging near-quantitative photoswitch pyrrole hemithioindigo, by rationally designing photopharmaceutical PHTub inhibitors of the cytoskeletal protein tubulin. PHTubs allow simultaneous visible-light imaging and photoswitching in live cells, delivering cell-precise photomodulation of microtubule dynamics, and photocontrol over cell cycle progression and cell death. This is the first acute use of a hemithioindigo photopharmaceutical for high-spatiotemporal-resolution biological control in live cells. It additionally demonstrates the utility of near-quantitative photoswitches, by enabling a dark-active design to overcome residual background activity during cellular photopatterning. This work opens up new horizons for high-precision microtubule research using PHTubs and shows the cellular applicability of pyrrole hemithioindigo as a valuable scaffold for photocontrol of a range of other biological targets.
Asunto(s)
Antimitóticos/metabolismo , Carmin de Índigo/análogos & derivados , Microtúbulos/metabolismo , Pirroles/metabolismo , Análisis de la Célula Individual , Antimitóticos/química , Ciclo Celular , Muerte Celular , Línea Celular Tumoral , Células HeLa , Humanos , Carmin de Índigo/química , Carmin de Índigo/metabolismo , Microtúbulos/química , Estructura Molecular , Procesos Fotoquímicos , Pirroles/químicaRESUMEN
Microbial secondary metabolites (SMs) have been identified as an important natural source of drugs for several metabolic and neurological diseases. Along with biomedical applications, SMs are also used in the food and biochemical industries. SMs include natural products such as pigments, alkaloids, toxins, antimicrobials obtained from cultured microorganisms, while other non-cultivable microorganisms have also acted as a rich source of SMs. But, the isolation of SMs from these sources is a very tedious task. Metabolomics provides complete identification and structural information about the entire cellular metabolome under specific conditions using highly sophisticated instrumentation. Further, gene editing techniques such as cloning and gene refactoring, including advanced CRISPR-Cas, can be used for engineering microbes that have the potential to produce natural SMs that were not produced in native microbial strain. The present review describes integrated metabolomics and gene editing approaches for the synthesis of novel microbial SMs and their potential application towards drug discovery and development.
Asunto(s)
Desarrollo de Medicamentos/métodos , Descubrimiento de Drogas/métodos , Edición Génica/métodos , Metabolómica/métodos , Fenómenos Microbiológicos , Metabolismo Secundario , Alcaloides/metabolismo , Antimitóticos/metabolismo , Productos Biológicos , Sistemas CRISPR-Cas , Bases de Datos Factuales , Eliminación de Gen , Ingeniería Genética/métodos , Análisis Multivariante , Mutagénesis Insercional , Pigmentos Biológicos/metabolismo , Toxinas Biológicas/metabolismoRESUMEN
The colchicine binding site of tubulin is often used to screen the anti-mitotic compounds, which are widely used as anti-cancer therapies. In the present work, an affinity probe capillary electrophoresis (APCE) method was developed for determining the affinity of anti-mitotic compounds. To this end, a fluorescently labeled affinity probe, 5-carboxyfluorescein-colchicine (F-colchicine), was prepared for the affinity competition experiment. The probe can form a stable complex with tubulin with the binding stoichiometry of 0.75, and the dissociation constant Kd of the complex was determined as 5.7â¯×â¯10-5â¯mol/L. In the affinity competition experiment, F-colchicine was incubated with tubulin and the test compound in the solution. The F-colchicine-tubulin complexes and free F-colchicine were quickly separated by CE and the concentration of free F-colchicine was accurately determined with the laser induced fluorescence detection. The affinity constant of the tested compound can be measured with the affinity competition binding curve. The enantiomers of the anti-mitotic compound were evaluated by using the method. The binding affinity of the enantiomers displayed an enantioselective manner. Compared to other affinity binding assay methods, our method is more straightforward, more accurate, and more cost-effective.
Asunto(s)
Antimitóticos , Colchicina/metabolismo , Descubrimiento de Drogas/métodos , Electroforesis Capilar/métodos , Tubulina (Proteína)/metabolismo , Antimitóticos/análisis , Antimitóticos/química , Antimitóticos/metabolismo , Sitios de Unión , Colchicina/química , Fluoresceínas/química , Colorantes Fluorescentes/química , Unión Proteica , Reproducibilidad de los Resultados , Tubulina (Proteína)/químicaRESUMEN
A library of 1-benzyl-N-(2-(phenylamino)pyridin-3-yl)-1H-1,2,3-triazole-4-carboxamides (7a-al) have been designed, synthesized and screened for their anti-proliferative activity against some selected human cancer cell lines namely DU-145, A-549, MCF-7 and HeLa. Most of them have shown promising cytotoxicity against lung cancer cell line (A549), amongst them 7f was found to be the most potent anti-proliferative congener. Furthermore, 7f exhibited comparable tubulin polymerization inhibition (IC50 value 2.04⯵M) to the standard E7010 (IC50 value 2.15⯵M). Moreover, flow cytometric analysis revealed that this compound induced apoptosis via cell cycle arrest at G2/M phase in A549 cells. Induction of apoptosis was further observed by examining the mitochondrial membrane potential and was also confirmed by Hoechst staining as well as Annexin V-FITC assays. Furthermore, molecular docking studies indicated that compound 7f binds to the colchicine binding site of the ß-tubulin. Thus, 7f exhibits anti-proliferative properties by inhibiting the tubulin polymerization through the binding at the colchicine active site and by induction of apoptosis.
Asunto(s)
Aminopiridinas/farmacología , Antimitóticos/farmacología , Triazoles/farmacología , Aminopiridinas/síntesis química , Aminopiridinas/química , Aminopiridinas/metabolismo , Animales , Antimitóticos/síntesis química , Antimitóticos/química , Antimitóticos/metabolismo , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Diseño de Fármacos , Ensayos de Selección de Medicamentos Antitumorales , Puntos de Control de la Fase G2 del Ciclo Celular/efectos de los fármacos , Humanos , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Simulación del Acoplamiento Molecular , Estructura Molecular , Polimerizacion/efectos de los fármacos , Unión Proteica , Ratas , Oveja Doméstica , Relación Estructura-Actividad , Triazoles/síntesis química , Triazoles/química , Triazoles/metabolismo , Tubulina (Proteína)/química , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/síntesis química , Moduladores de Tubulina/química , Moduladores de Tubulina/metabolismo , Moduladores de Tubulina/farmacologíaRESUMEN
Zinc oxide nanoparticles synthesized through eco-friendly approach has gained importance among researchers due to its broad applications. In the present work, hexagonal wurtzite shape nanoparticles (below 100 nm size) were obtained using aqueous leaf extract of Cochlospermum religiosum which was confirmed through X-Ray diffraction (XRD) analysis. The synthesized ZnO-NPs showed an absorption peak at 305 nm which is one of the characteristic features of ZnO-NPs.The bio-fabricated ZnO-NPs were of high purity with an average size of â¼76 nm analyzed through Dynamic Light Scattering (DLS) analysis supporting the findings of XRD. The SEM images confirmed the same with agglomeration of smaller nanoparticles. The composition of aqueous leaf extract and ZnO-NPs was explored with Fourier Transform Infrared Spectroscopy (FT-IR). The plant extract as well as bio-fabricated ZnO-NPs offered significant inhibition against Gram-positive (B. subtilis and Staph. aureus) and Gram-negative (P. aeruginosa and E. coli) bacteria. The minimum inhibitory concentration (MIC) of bio-fabricated ZnO-NPs and plant extract was found between 4.8 and 625 µg/ml against test pathogens, which was authenticated with live and dead cell analysis. Apart from antibacterial potentiality, antimitotic activity was also observed with a mitotic index of 75.42% (ID50 0.40 µg mL-1) and 61.41% (ID50 0.58 µg mL-1) in ZnO-NPs and plant extract, respectively. The results affirm that plant extract and its mediated ZnO-NPs possess biological properties.
Asunto(s)
Antibacterianos/metabolismo , Antimitóticos/metabolismo , Bixaceae/química , Nanopartículas/metabolismo , Extractos Vegetales/aislamiento & purificación , Óxido de Zinc/metabolismo , Allium/efectos de los fármacos , Antibacterianos/aislamiento & purificación , Antimitóticos/aislamiento & purificación , Proliferación Celular/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Rastreo , Nanopartículas/ultraestructura , Células Vegetales/efectos de los fármacos , Extractos Vegetales/química , Hojas de la Planta/química , Difracción de Rayos X , Óxido de Zinc/aislamiento & purificaciónRESUMEN
Production of ribosomally synthesized and posttranslationally modified peptides (RiPPs) has rarely been reported in fungi, even though organisms of this kingdom have a long history as a prolific source of natural products. Here we report an investigation of the phomopsins, antimitotic mycotoxins. We show that phomopsin is a fungal RiPP and demonstrate the widespread presence of a pathway for the biosynthesis of a family of fungal cyclic RiPPs, which we term dikaritins. We characterize PhomM as an S-adenosylmethionine-dependent α-N-methyltransferase that converts phomopsin A to an N,N-dimethylated congener (phomopsin E), and show that the methyltransferases involved in dikaritin biosynthesis have evolved differently and likely have broad substrate specificities. Genome mining studies identified eight previously unknown dikaritins in different strains, highlighting the untapped capacity of RiPP biosynthesis in fungi and setting the stage for investigating the biological activities and unknown biosynthetic transformations of this family of fungal natural products.
Asunto(s)
Ascomicetos/metabolismo , Micotoxinas/biosíntesis , Secuencia de Aminoácidos , Antimitóticos/química , Antimitóticos/metabolismo , Ascomicetos/genética , Productos Biológicos/química , Productos Biológicos/metabolismo , Vías Biosintéticas , Proteínas Fúngicas/biosíntesis , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Genes Fúngicos , Datos de Secuencia Molecular , Familia de Multigenes , Micotoxinas/química , Micotoxinas/genética , Proteína Metiltransferasas/genética , Proteína Metiltransferasas/metabolismo , Procesamiento Proteico-Postraduccional , Secuencias Repetitivas de Aminoácido , Ribosomas/metabolismoRESUMEN
This study reports the synthesis of a series of heteroaroyl-2-hydroxy-3,4,5-trimethoxybenzenes, which are potent antitubulin agents. Compound 13, (2-hydroxy-3,4,5-trimethoxyphenyl)-(6-methoxy-1H-indol-3-yl)-methanone exhibits marked antiproliferative activity against KB and MKN45 cells with IC50 values of 8.8 and 10.5 nM, respectively, binds strongly to the colchicine binding site and leads to inhibition of tubulin polymerization. It also behaves as a vascular disrupting agent which suppresses the formation of capillaries. The C2-OH group in the A-ring of this compound not only retains the biological activity but has valuable physicochemical properties.
Asunto(s)
Antimitóticos/química , Antimitóticos/farmacología , Evaluación Preclínica de Medicamentos/métodos , Inhibidores de la Angiogénesis/química , Inhibidores de la Angiogénesis/farmacología , Antimitóticos/metabolismo , Benceno/química , Sitios de Unión , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Técnicas de Química Sintética , Colchicina/metabolismo , Resistencia a Antineoplásicos/efectos de los fármacos , Células HT29/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Humanos , Concentración 50 Inhibidora , Relación Estructura-Actividad , Moduladores de Tubulina/química , Moduladores de Tubulina/metabolismo , Moduladores de Tubulina/farmacologíaRESUMEN
A series of aryloxazole, thiazole, and isoxazole derivatives was synthesized as vascular-targeting anticancer agents. Antiproliferative activity and tumor vascular-disrupting activity of all of the synthesized compounds were tested in vitro using various human cancer cell lines and HUVECs (human umbilical vein endothelial cells). Several compounds with an arylpiperazinyl oxazole core showed excellent cytotoxicity and metabolic stability in vitro. Among this series, two representative compounds (6-48 and 6-51) were selected and tested for the evaluation of anticancer effects in vivo using tumor-bearing mice. Compound 6-48 effectively reduced tumor growth (42.3% reduction in size) at the dose of 100 mg/kg. We believe that compound 6-48 will serve as a good lead compound for antimitotic and vascular-disrupting agents; further investigation to improve the in vivo efficacy of this series is underway.
Asunto(s)
Antimitóticos/síntesis química , Antimitóticos/farmacología , Vasos Sanguíneos/efectos de los fármacos , Oxazoles/síntesis química , Oxazoles/farmacología , Animales , Antimitóticos/química , Antimitóticos/metabolismo , Proliferación Celular/efectos de los fármacos , Técnicas de Química Sintética , Estabilidad de Medicamentos , Células HL-60 , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Microsomas Hepáticos/metabolismo , Modelos Moleculares , Oxazoles/química , Oxazoles/metabolismo , Multimerización de Proteína/efectos de los fármacos , Estructura Cuaternaria de Proteína , Relación Estructura-Actividad , Tubulina (Proteína)/química , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Nitrogen-containing bioactive alkaloids of plant origin play a significant role in human health and medicine. Several semisynthetic antimitotic alkaloids are successful in anticancer drug development. Gloriosa superba biosynthesizes substantial quantities of colchicine, a bioactive molecule for gout treatment. Colchicine also has antimitotic activity, preventing growth of cancer cells by interacting with microtubules, which could lead to the design of better cancer therapeutics. Further, several colchicine semisynthetics are less toxic than colchicine. Research is being conducted on effective, less toxic colchicine semisynthetic formulations with potential drug delivery strategies directly targeting multiple solid cancers. This article reviews the dynamic state of anticancer drug development from colchicine semisynthetics and natural colchicine production and briefly discusses colchicine biosynthesis.
Asunto(s)
Antimitóticos/metabolismo , Colchicina/biosíntesis , Moduladores de Tubulina/metabolismo , Antimitóticos/química , Antimitóticos/uso terapéutico , Colchicina/química , Colchicina/uso terapéutico , Sistemas de Liberación de Medicamentos , Humanos , Liliaceae/química , Liliaceae/metabolismo , Nanomedicina , Neoplasias/tratamiento farmacológico , Moduladores de Tubulina/química , Moduladores de Tubulina/uso terapéuticoRESUMEN
Through metabolic profiling of mutants and wild type of the endofungal bacterium Burkholderia rhizoxinica two novel rhizoxin derivatives with unusual nitrile substitutions were discovered. The nitrile groups result from a photochemical oxidative cleavage of the oxazolyl moiety. In vitro studies revealed that the photooxidation by singlet oxygen also takes place in the absence of a photosensitizer, and that also a thiazolyl-substituted rhizoxin analogue undergoes the same transformation. The resulting nitriles have antimitotic properties but are significantly less active than the parent compounds. These results highlight the impact of photoreactions onto the antiproliferative agent and encourage the introduction of bioisosteric groups that render the compound less susceptible towards photooxidation.
Asunto(s)
Antimitóticos/química , Antimitóticos/farmacología , Macrólidos/química , Macrólidos/farmacología , Nitrilos/química , Oxazoles/química , Procesos Fotoquímicos , Antimitóticos/metabolismo , Línea Celular Tumoral , Humanos , Macrólidos/metabolismoRESUMEN
Antimitotic compounds are still one of the most widely used chemotherapeutic anticancer drugs in the clinic today. Given their effectiveness against cancer it is beneficial to continue enhancing these drugs. One way is to improve the bioavailability and efficacy by synthesizing derivatives that reversibly bind to carbonic anhydrase II (CAII) in red blood cells followed by a slow release into the blood circulation system. In the present study we describe the in vitro biological activity of a reduced derivative of 2-ethyl-3-O-sulphamoyl-estradiol (2EE), 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10),15-tetraen-17-ol (ESE-15-ol). ESE-15-ol is capable of inhibiting carbonic anhydrase activity in the nanomolar range and is selective towards a mimic of carbonic anhydrase IX when compared to the CAII isoform. Docking studies using Autodock Vina suggest that the dehydration of the D-ring plays a role towards the selectivity of ESE-15-ol to CAIX and that the binding mode of ESE-15-ol is substantially different when compared to 2EE. ESE-15-ol is able to reduce cell growth to 50% after 48 h at 50-75 nM in MCF-7, MDA-MB-231, and MCF-12A cells. The compound is the least potent against the non-tumorigenic MCF-12A cells. In vitro mechanistic studies demonstrate that the newly synthesized compound induces mitochondrial membrane depolarization, abrogates the phosphorylation status of Bcl-2 and affects gene expression of genes associated with cell death and mitosis.
Asunto(s)
Antimitóticos/farmacología , Inhibidores de Anhidrasa Carbónica/farmacología , Anhidrasas Carbónicas/metabolismo , Estradiol/análogos & derivados , Estradiol/farmacología , Sulfonamidas/metabolismo , Sulfonamidas/farmacología , Antimitóticos/química , Antimitóticos/metabolismo , Inhibidores de Anhidrasa Carbónica/química , Inhibidores de Anhidrasa Carbónica/metabolismo , Anhidrasas Carbónicas/química , Ciclo Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Estradiol/metabolismo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Células MCF-7 , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Simulación del Acoplamiento Molecular , Metástasis de la Neoplasia , Fosforilación/efectos de los fármacos , Conformación Proteica , Proteínas Proto-Oncogénicas c-bcl-2/química , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Serina/metabolismo , Tubulina (Proteína)/química , Tubulina (Proteína)/metabolismoRESUMEN
1-(4-Methoxyphenylethyl)-11H-benzo[f]-1,2-dihydro-pyrido[3,2,c][1,2,5]oxathiazepine 5,5 dioxide (BZN) is a cytotoxic derivative with very promising in vitro activity. Regulatory authority for registration of pharmaceuticals for human use requires to evaluate the stability of active compound under various stress conditions. Forced degradation of BZN was investigated under hydrolytic (0.1M NaOH, 0.1M HCl, neutral), oxidative (3.3% H(2)O(2)), photolytic (visible light) and thermal (25 °C, 70 °C) settings. Relevant degradation took place under thermal acidic (0.1M HCl, 70 °C) and oxidative (3.3% H(2)O(2)) conditions. Liquid chromatography-mass spectrometry (LC-MS) analyses revealed the presence of ten degradation products whose structures were characterized by electrospray ionization-orbitrap mass spectrometry. The full scan accurate mass analysis of degradation products was confirmed or refuted using three tools furnished by the MS software: (1) predictive chemical formula and corresponding mass error; (2) double bond equivalent (DBE) calculation; and (3) accurate mass product ion spectra of degradation products. The structural elucidation showed that the tricycle moiety was unstable under thermal acidic and oxidative conditions since four degradation products possess an opened oxathiazepine ring. Then, a simple and fast HPLC-UV method was developed and validated for the determination of the degradation kinetic of BZN under acidic and oxidative conditions. The method was linear in the 5-100 µg mL(-1) concentration range with a good precision (RSD=2.2% and 2.7% for the repeatability and the intermediate precision, respectively) and a bias which never exceeded 1.6%, whatever the quality control level. With regards to the BZN concentration, a first-order degradation process was determined, with t(1/2)=703 h and 1140 h, under oxidative and acidic conditions, respectively.
Asunto(s)
Antimitóticos/química , Tiazepinas/química , Ácidos/química , Antimitóticos/metabolismo , Cromatografía Liquida/métodos , Estabilidad de Medicamentos , Concentración de Iones de Hidrógeno , Hidrólisis , Cinética , Oxidación-Reducción , Fotólisis , Reproducibilidad de los Resultados , Espectrometría de Masa por Ionización de Electrospray/métodos , Estrés Fisiológico , Tiazepinas/metabolismoRESUMEN
The importance of the bridge linking the two phenyl moieties of substituted phenyl 4-(2-oxoimidazolidin-1-yl)benzenesulfonates (PIB-SOs) was assessed using a sulfonamide group, which is a bioisostere of sulfonate and ethenyl groups. Forty one phenyl 4-(2-oxoimidazolidin-1-yl)benzenesulfonamide (PIB-SA) derivatives were prepared and biologically evaluated. PIB-SAs exhibit antiproliferative activities at the nanomolar level against sixteen cancer cell lines, block the cell cycle progression in G(2)/M phase, leading to cytoskeleton disruption and anoikis. These results were subjected to CoMFA and CoMSIA analyses to establish quantitative structure-activity relationships. These results evidence that the sulfonate and sulfonamide moieties are reciprocal bioisosteres and that phenylimidazolidin-2-one could mimic the trimethoxyphenyl moiety found in the structure of numerous potent antimicrotubule agents. Finally, compounds 16 and 17 exhibited potent antitumor and antiangiogenic activities on HT-1080 fibrosarcoma cells grafted onto chick chorioallantoic membrane similar to CA-4 without significant toxicity for the chick embryos, making this class of compounds a promising class of anticancer agents.
Asunto(s)
Inhibidores de la Angiogénesis/química , Inhibidores de la Angiogénesis/farmacología , Antimitóticos/química , Antimitóticos/farmacología , Relación Estructura-Actividad Cuantitativa , Sulfonamidas/química , Sulfonamidas/farmacología , Inhibidores de la Angiogénesis/metabolismo , Animales , Antimitóticos/metabolismo , Sitios de Unión , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Embrión de Pollo , Membrana Corioalantoides/efectos de los fármacos , Membrana Corioalantoides/patología , Colchicina/metabolismo , Humanos , Modelos Moleculares , Conformación Molecular , Sulfonamidas/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto , BencenosulfonamidasRESUMEN
Compounds that modulate microtubule dynamics include highly effective anticancer drugs, leading to continuing efforts to identify new agents and improve the activity of established ones. Here, we demonstrate that [(3)H]-labeled halichondrin B (HB), a complex, sponge-derived natural product, is bound to and dissociated from tubulin rapidly at one binding site per αß-heterodimer, with an apparent K(d) of 0.31 µM. We found no HB-induced aggregation of tubulin by high-performance liquid chromatography, even following column equilibration with HB. Binding of [(3)H]HB was competitively inhibited by a newly approved clinical agent, the truncated HB analogue eribulin (apparent K(i), 0.80 µM) and noncompetitively by dolastatin 10 and vincristine (apparent K(i)'s, 0.35 and 5.4 µM, respectively). Our earlier studies demonstrated that HB inhibits nucleotide exchange on ß-tubulin, and this, together with the results presented here, indicated the HB site is located on ß-tubulin. Using molecular dynamics simulations, we determined complementary conformations of HB and ß-tubulin that delineated in atomic detail binding interactions of HB with only ß-tubulin, with no involvement of the α-subunit in the binding interaction. Moreover, the HB model served as a template for an eribulin binding model that furthered our understanding of the properties of eribulin as a drug. Overall, these results established a mechanistic basis for the antimitotic activity of the halichondrin class of compounds.
Asunto(s)
Antimitóticos/metabolismo , Éteres Cíclicos/metabolismo , Furanos/metabolismo , Cetonas/metabolismo , Modelos Moleculares , Tubulina (Proteína)/metabolismo , Animales , Sitios de Unión , Bovinos , Macrólidos , Simulación de Dinámica Molecular , Poríferos , Unión Proteica , Multimerización de Proteína , Estructura Cuaternaria de Proteína , Tubulina (Proteína)/químicaRESUMEN
3-(1H-Indol-2-yl)phenyl)(3,4,5-trimethoxyphenyl)methanone (I-387) is a novel indole compound with antitubulin action and potent antitumor activity in various preclinical models. I-387 avoids drug resistance mediated by P-glycoprotein and showed less neurotoxicity than vinca alkaloids during in vivo studies. We examined the pharmacokinetics and metabolism of I-387 in mice as a component of our preclinical development of this compound and continued interest in structure-activity relationships for antitubulin agents. After a 1 mg/kg intravenous dose, noncompartmental pharmacokinetic analysis in plasma showed that clearance (CL), volume of distribution at steady state (Vd(ss)), and terminal half-life (t(1/2)) of I-387 were 27 ml per min/kg, 5.3 l/kg, and 7 h, respectively. In the in vitro metabolic stability study, half-lives of I-387 were between 10 and 54 min by mouse, rat, dog, monkey, and human liver microsomes in the presence of NADPH, demonstrating interspecies variability. I-387 was most stable in rat liver microsomes and degraded quickly in monkey liver microsomes. Liquid chromatography-tandem mass spectrometry was used to identify phase I metabolites. Hydroxylation, reduction of a ketone group, and O-demethylation were the major metabolites formed by the liver microsomes of the five species. The carbonyl group of I-387 was reduced and identified as the most labile site in human liver microsomes. The results of these drug metabolism and pharmacokinetic studies provide the foundation for future structural modification of this pharmacophore to improve stability of drugs with potent anticancer effects in cancer patients.