Biological Characterization of an Improved Pyrrole-Based Colchicine Site Agent Identified through Structure-Based Design.
Mol Pharmacol
; 89(2): 287-96, 2016 Feb.
Article
em En
| MEDLINE
| ID: mdl-26655304
ABSTRACT
A refined model of the colchicine site on tubulin was used to design an improved analog of the pyrrole parent compound, JG-03-14. The optimized compound, NT-7-16, was evaluated in biological assays that confirm that it has potent activities as a new colchicine site microtubule depolymerizer. NT-7-16 exhibits antiproliferative and cytotoxic activities against multiple cancer cell lines, with IC(50) values of 10-16 nM, and it is able to overcome drug resistance mediated by the expression of P-glycoprotein and the ßIII isotype of tubulin. NT-7-16 initiated the concentration-dependent loss of cellular microtubules and caused the formation of abnormal mitotic spindles, leading to mitotic accumulation. The direct interaction of NT-7-16 with purified tubulin was confirmed, and it was more potent than combretastatin A-4 in these assays. Binding studies verified that NT-7-16 binds to tubulin within the colchicine site. The antitumor effects of NT-7-16 were evaluated in an MDA-MB-435 xenograft model and it had excellent activity at concentrations that were not toxic. A second compound, NT-9-21, which contains dichloro moieties in place of the 3,5-dibromo substituents of NT-7-16, had a poorer fit within the colchicine site as predicted by modeling and the Hydropathic INTeractions score. Biological evaluations showed that NT-9-21 has 10-fold lower potency than NT-7-16, confirming the modeling predictions. These studies highlight the value of the refined colchicine-site model and identify a new pyrrole-based colchicine-site agent with potent in vitro activities and promising in vivo antitumor actions.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pirróis
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Tubulina (Proteína)
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Colchicina
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Simulação de Acoplamento Molecular
Tipo de estudo:
Prognostic_studies
Limite:
Animals
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Female
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Humans
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article