RESUMEN
A series of 2-pyridylhydrazones derived from phenyl-pyridazin-3-yl-methanones were prepared in search for potential novel antitumor agents. The stereochemistry of these compounds was established by means of NMR spectroscopy. Whereas hydrazones derived from 3-benzoylpyridazines (IC50 = 0.99-8.74 µM) inhibited the proliferation of the tumor cell lines tested, the non-fully aromatic 3-benzoylpyridazinone hydrazones (IC50 >10 µM) turned out to be inactive. Compounds E-1b (IC50 = 0.12 µM) and E-1d (IC50 = 0.18 µM) exert high cytotoxic activities in clonogenic assays involving human tumor cells of different tissue origins. In vivo application of compound E-1b (300 mg/kg/day) resulted in a 66% reduction in tumor burden.
Asunto(s)
Antineoplásicos/síntesis química , Proliferación Celular/efectos de los fármacos , Hidrazonas/síntesis química , Piridazinas/química , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Hidrazonas/química , Hidrazonas/farmacología , Hidrazonas/uso terapéutico , Concentración 50 Inhibidora , Ratones Desnudos , Estructura Molecular , Especificidad de Órganos , Ensayo de Tumor de Célula Madre , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
The novel compound N-benzoxazol-2-yl-N'-1-(isoquinolin-3-yl-ethylidene)-hydrazine (EPH136) has been shown to exhibit antitumor activity in vitro and in vivo. A COMPARE analysis showed that the patterns of cellular effects of EPH136 are not related to any of 175 standard antitumor agents with a known mechanism of action. In order to help identify the mechanism of action we employed a bioinformatics approach called partial least squares modelling in latent variables in which the expression levels of approximately 8,000 genes in each of 56 untreated NCI panel cell lines were correlated with the respective IC(50) values of each cell line following treatment with EPH136. The 60 genes found to be most important for the antiproliferative effect of EPH136 are involved in nucleoside, nucleotide, nucleic acid binding and metabolism, developmental processes, protein modification and metabolism. In addition, using a DNA microarray we measured the expression of approximately 5,000 known genes following treatment of HT-29 colon carcinoma cells with a two-fold IC(50) concentration of EPH136. The genes that were up-regulated more than two-fold compared to untreated controls belong to the same classes as found by the bioinformatic approach. Many of these proteins are regulated by oxidation/reduction and so we concluded that formation of radicals may be involved in the mechanism of action. We show here that EPH136 leads to generation of oxygen radicals, swelling of mitochondria and dissipation of the mitochondrial membrane potential. The antiproliferative activity of EPH136 was prevented by the radical scavenger N-acetylcysteine. Cells with elevated glutathione exhibited resistance to EPH136. In summary, the mechanism of the novel experimental anticancer drug EPH136 is generation of radicals and dissipation of the mitochondrial membrane potential.
Asunto(s)
Antineoplásicos/farmacología , Benzoxazoles/farmacología , Radicales Libres/metabolismo , Hidrazonas/farmacología , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Antineoplásicos/química , Antioxidantes/farmacología , Apoptosis/efectos de los fármacos , Benzoxazoles/química , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Biología Computacional , ADN/biosíntesis , Ensayos de Selección de Medicamentos Antitumorales , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Hidrazonas/química , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN/biosíntesis , Especies Reactivas de Oxígeno/metabolismo , Ribonucleótido Reductasas/antagonistas & inhibidoresRESUMEN
Recently we have described the antitumor activities of 2-benzoxazolylhydrazones derived from 2-formyl and 2-acetylpyridines. In search of a more efficacious analogue, compounds in which the 2-acetylpyridine moiety has been replaced by 2-acylpyridine and alpha-(N)-acetyldiazine/quinoline groups have been synthesized. The 2-acylpyridyl hydrazones inhibited in vitro cell proliferation in the nM range, whereas the hydrazones derived from the alpha-(N)-acetyldiazines/quinolines inhibited cell growth in the muM range. Compounds tested in the NCI-60 cell assay were effective inhibitors of leukemia, colon, and ovarian cancer cells. E-13k [N-benzoxazol-2-yl-N'-(1-isoquinolin-3-yl-ethylidene)-hydrazine] inhibited the proliferation of MCF-7 breast carcinoma cells more efficiently than nontransformed MCF-10A cells. It is not transported by P-glycoprotein and a weak MRP substrate. Increased concentrations of serum or alpha(1)-acid glycoprotein did not reduce the antiproliferative activity of the compound. In the in vivo hollow fiber assay, E-13k achieved a score of 24, with a net cell kill of OVCAR-3 (ovarian) and SF2-95 (CNS) tumor cells.
Asunto(s)
Antineoplásicos/síntesis química , Benzoxazoles/síntesis química , Hidrazonas/síntesis química , Antineoplásicos/química , Antineoplásicos/farmacología , Benzoxazoles/química , Benzoxazoles/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Resistencia a Antineoplásicos , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Hidrazonas/química , Hidrazonas/farmacología , Especificidad de Órganos , Estereoisomerismo , Relación Estructura-ActividadRESUMEN
Pyridazino[3,4-b][1,5]benzoxazepin-5(6H)ones substituted with propylene-linked basic side chains were synthesized and investigated for the ability to reverse multidrug resistance (MDR) at vincristine-pretreated HeLa-MDR1 cells. The substances were found to be effective chemosensitizers with activity comparable to that of the known MDR modulator verapamil. The observed antiproliferative effects were not caused by direct drug cytotoxicity.