RESUMO
Steroid dimers of natural and synthetic origin possess an unusual and complex molecular architecture that may lead to the realization of peculiar effects in biological systems, in particular in different cancer cell lines. In the present work, diastereoselective ring-opening of mono- and polyoxiranes, containing a cyclooctane core, by azide-anion was performed to yield a series of azidoalcohols with different types of symmetry. The products were involved in copper-catalyzed azyde-alkyne cycloaddition (CuAAC) reaction with ethinylestradiol and ethinyltestosterone, and the resulting steroids and steroid dimers with triazole linkers were screened for their antiproliferative activity via (3-(4,5-dimethylthiazol-2-yl)2,5-diphenyl tetrazolium bromide) assay. All the compounds revealed cytotoxicity toward several cancer cell lines. The effect of the most potent compound, containing two estradiol moieties, on the microtubules (MT) dynamics was investigated by immunofluorescent microscopy. The disruption of the majority of interphase cell cytoplasmic MT and mitotic event disturbances in the presence of the studied compound were observed. The latter effect caused the appearance of numerous multinucleated cells.
RESUMO
Tubulin-targeting agents attract undiminished attention as promising compounds for the design of anti-cancer drugs. Verubulin is a potent tubulin polymerization inhibitor, binding to colchicine-binding sites. In the present work, a series of verubulin analogues containing a cyclohexane or cycloheptane ring 1,2-annulated with pyrimidine moiety and various substituents in positions 2 and 4 of pyrimidine were obtained and their cytotoxicity towards cancer and non-cancerous cell lines was estimated. The investigated compounds revealed activity against various cancer cell lines with IC50 down to 1-4 nM. According to fluorescent microscopy data, compounds that showed cytotoxicity in the MTT test disrupt the normal cytoskeleton of the cell in a pattern similar to that for combretastatin A-4. The hit compound (N-(4-methoxyphenyl)-N,2-dimethyl-5,6,7,8-tetrahydroquinazolin-4-amine) was encapsulated in biocompatible nanocontainers based on Ca2+ or Mg2+ cross-linked alginate and it was demonstrated that its cytotoxic activity was preserved after encapsulation.
RESUMO
A series of novel antimitotic agents was designed using the replacement of heterocyclic cores in two tubulin-targeting lead molecules with the acylated 4-aminoisoxazole moiety. Target compounds were synthesized via heterocyclization of ß-aryl-substituted vinylketones by tert-butyl nitrite in the presence of water as a key step. 4-Methyl-N-[5-methyl-3-(3,4,5-trimethoxyphenyl)isoxazol-4-yl]benzamide (1aa) was found to stimulate partial depolymerization of microtubules of human lung carcinoma A549 cells at a high concentration of 100 µM and to totally inhibit cell growth (IC50 = 0.99 µM) and cell viability (IC50 = 0.271 µM) in the nanomolar to submicromolar concentration range. These data provide evidence of the multitarget profile of the cytotoxic action of compound 1aa. The SAR study demonstrated that the 3,4,5-trimethoxyphenyl residue is the key structural parameter determining the efficiency both towards tubulin and other molecular targets. The cytotoxicity of 3-methyl-N-[5-methyl-3-(3,4,5-trimethoxyphenyl)isoxazol-4-yl]benzamide (1ab) to the androgen-sensitive human prostate adenocarcinoma cancer cell line LNCaP (IC50 = 0.301 µM) was approximately one order of magnitude higher than that to the conditionally normal cells lines WI-26 VA4 (IC50 = 2.26 µM) and human umbilical vein endothelial cells (IC50 = 5.58 µM) and significantly higher than that to primary fibroblasts (IC50 > 75 µM).
Assuntos
Antimitóticos , Antineoplásicos , Neoplasias , Antimitóticos/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Apoptose , Benzamidas/farmacologia , Linhagem Celular Tumoral , Proliferação de Células , Células Endoteliais/metabolismo , Humanos , Relação Estrutura-Atividade , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/farmacologiaRESUMO
Tubuloclustin [N-(7-adamant-2-yloxy-7-oxoheptanoyl)-N-deacetylcolchicine], a highly cytotoxic anti-tubulin compound is known for its ability to promote microtubule disassembly followed by the formation of tubulin clusters of unique morphology. Three series of antimitotic agents related to tubuloclustin were designed and synthesized in order to enhance the molecular diversity of "tubuloclustin-like" family of compounds. The series of compounds with modified adamantane moiety was highly potent in cytotoxic effect on human lung carcinoma A549 cells (EC50 = 6-400 nM) and was active in affecting the microtubule arrays and induction of strong tubulin clusterization. In two other sets of compounds, the colchicine moiety of tubuloclustin was replaced by podophyllotoxin or combretastatin A-4. All combretastatin A-4 derivatives displayed noticeable cytotoxic activity ([Formula: see text]) but their effect on microtubules depended on the position of the linker attachment. Podophyllotoxin derivatives were also toxic to A549 cells ([Formula: see text]) and caused both microtubule depolymerization and some tubulin clustering. The data obtained gave additional evidence that the whole panel of C7-colchicine, podophyllotoxin and combretastatin derivatives could manifest clustering effect, and the strength of this effect correlated with cytotoxic activity of the compounds.
Assuntos
Adamantano/análogos & derivados , Antimitóticos/síntese química , Colchicina/análogos & derivados , Tubulina (Proteína)/metabolismo , Células A549 , Adamantano/química , Antimitóticos/química , Antimitóticos/farmacologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Colchicina/química , Humanos , Modelos Moleculares , Estrutura Molecular , Tubulina (Proteína)/químicaRESUMO
Highly cytotoxic C7-modified colchicine analogues, exemplified by tubuloclustin, promote microtubule disassembly followed by the formation of very stable tubulin clusters, both in vitro and in cells. The proposed mechanism of action of tubuloclustin and its analogues, beyond that of colchicine, includes additional specific interactions with the α-tubulin subunit.
Assuntos
Adamantano/análogos & derivados , Colchicina/análogos & derivados , Colchicina/farmacologia , Tubulina (Proteína)/metabolismo , Adamantano/química , Adamantano/farmacologia , Animais , Células Cultivadas , Colchicina/química , Citotoxinas/química , Citotoxinas/farmacologia , Citometria de Fluxo , Imunofluorescência , Células HeLa , Humanos , Camundongos , Microscopia Eletrônica de Transmissão , Estrutura Molecular , Ligação Proteica/efeitos dos fármacosRESUMO
A series of analogues of conjugate 1, combining an adamantane-based paclitaxel (taxol) mimetic with colchicine was synthesized and tested for cytotoxicity in a cell-based assay with the human lung carcinoma cell line A549. The most active compounds (10 EC(50) 2 ± 1.0 nM, 23 EC(50) 6 ± 1.4 nM, 26 EC(50) 5 ± 1.8 nM, 28 EC(50) 11 ± 1.7 nM, 30 EC(50) 4.8 ± 0.5 nM) were found to interfere with the microtubule dynamics in an interesting manner. Treatment of the cells with these compounds promoted disassembly of microtubules followed by the formation of stable tubulin clusters. Structure-activity relationships for the analogues of 23 revealed the sensitivity of both cytotoxicity and tubulin clustering ability to the linker length. The presence of adamantane (or another bulky hydrophobic and non-aromatic moiety) in 23 was found to play an important role in the formation of tubulin clusters. Structural requirements for optimal activity have been partially explained by molecular modeling.
Assuntos
Adamantano/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Colchicina/farmacologia , Microtúbulos/efeitos dos fármacos , Tubulina (Proteína)/metabolismo , Adamantano/química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Colchicina/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Microtúbulos/metabolismo , Modelos Moleculares , Estrutura Molecular , Paclitaxel/química , Paclitaxel/farmacologia , Estereoisomerismo , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
Several adamantane-based taxol mimetics were synthesized and found to be cytotoxic at micromolar concentrations and to cause tubulin aggregation. The extent of the aggregation is maximal for N-benzoyl-(2R,3S)-phenylisoseryloxyadamantane (5) and is very sensitive to the structural modifications. A hybrid compound (15), combining adamantane-based taxol mimetic with colchicine was synthesized and found to possess both microtubule depolymerizing and microtubule bundling activities in A549 human lung carcinoma cells.