RESUMEN
Six compounds were synthesized with piperazine in linker region and hydroxamate as Zinc Binding Group (ZBG). They were screened against three cancer cell-lines (NCIH460; HCT116; U251). Compounds 5c and 5f with GI(50) value of 9.33+/-1.3 microM and 12.03+/-4 microM, respectively, were tested for their inhibitory potential on hHDAC8. Compound 5c had IC(50) of 33.67 microM. Compounds were also screened for their anticancer activity against HL60 human promyelocytic leukemia cell line due to the presence of pharmacophoric features of RR inhibitors in them. Compound 5c had IC(50) of 0.6 microM at 48h.
Asunto(s)
Antineoplásicos/farmacología , Diseño de Fármacos , Inhibidores de Histona Desacetilasas/farmacología , Histona Desacetilasas/metabolismo , Ácidos Hidroxámicos/farmacología , Piperazinas/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Inhibidores de Histona Desacetilasas/síntesis química , Inhibidores de Histona Desacetilasas/química , Humanos , Ácidos Hidroxámicos/síntesis química , Ácidos Hidroxámicos/química , Modelos Moleculares , Estructura Molecular , Piperazina , Piperazinas/síntesis química , Piperazinas/química , Estereoisomerismo , Relación Estructura-ActividadRESUMEN
DNA damage induced by the topoisomerase I inhibitor irinotecan (CPT-11) triggers in p53(WT) colorectal carcinoma cells a long term cell cycle arrest and in p53MUT cells a transient arrest followed by apoptosis (Magrini, R., Bhonde, M. R., Hanski, M. L., Notter, M., Scherübl, H., Boland, C. R., Zeitz, M., and Hanski, C. (2002) Int. J. Cancer 101, 23-31; Bhonde, M. R., Hanski, M. L., Notter, M., Gillissen, B. F., Daniel, P. T., Zeitz, M., and Hanski, C. (2006) Oncogene 25, 165-175). The mechanism of the p53-independent apoptosis still remains largely unclear. Here we used five p53WT and five p53MUT established colon carcinoma cell lines to identify gene expression alterations associated with apoptosis in p53MUT cells after treatment with SN-38, the irinotecan metabolite. After treatment, 16 mitosis-related genes were found to be expressed at least 2-fold stronger in the apoptosis-executing p53MUT cells than in the cell cycle-arrested p53WT cells by oligonucleotide microarray analysis. One of the genes whose strong post-treatment expression was associated with apoptosis was the mitotic checkpoint kinase hMps1 (human ortholog of the yeast monopolar spindle 1 kinase). hMps1 mRNA and protein expression were suppressed by the treatment-induced and by the exogenous adenovirus-coded p53 protein. The direct suppression of hMps1 on RNA level or inhibition of its activity by a dominant-negative hMps1 partly suppressed apoptosis. Together, these data indicate that the high expression of mitotic genes in p53MUT cells after SN-38 treatment contributes to DNA damage-induced apoptosis, whereas their suppression in p53WT cells acts as a safeguard mechanism preventing mitosis initiation and the subsequent apoptosis. hMps1 kinase is one of the mitotic checkpoint proteins whose expression after DNA damage in p53MUT cells activates the checkpoint and contributes to apoptosis.
Asunto(s)
Apoptosis , Proteínas de Ciclo Celular/metabolismo , Daño del ADN , Regulación Neoplásica de la Expresión Génica , Proteínas Serina-Treonina Quinasas/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Antineoplásicos Fitogénicos/farmacología , Western Blotting , Camptotecina/análogos & derivados , Camptotecina/farmacología , Carcinoma/genética , Carcinoma/metabolismo , Carcinoma/patología , Ciclo Celular/efectos de los fármacos , Proteínas de Ciclo Celular/genética , Línea Celular Tumoral , Neoplasias del Colon/genética , Neoplasias del Colon/metabolismo , Neoplasias del Colon/patología , Citometría de Flujo , Células HCT116 , Células HT29 , Células HeLa , Humanos , Irinotecán , Modelos Biológicos , Proteínas de Neoplasias/deficiencia , Proteínas Serina-Treonina Quinasas/genética , Proteínas Tirosina Quinasas , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Proteína p53 Supresora de Tumor/genéticaRESUMEN
The broad-range cyclin-dependent kinase inhibitor 7-hydroxystaurosporine (UCN-01) is known to induce both a G1 cell cycle arrest and apoptosis. The mechanism of UCN-01-induced apoptosis is largely unknown. We analysed the mechanism of cytotoxicity of UCN-01 in four established colon carcinoma cell lines. The cell lines SW48 and LS513 responded to UCN-01 treatment by undergoing apoptosis in a concentration-dependent manner while the cell lines HT-29 and WiDr were completely resistant. Apoptosis in LS513 and SW48 cell lines was concomitant with the suppression of Bcl-x(L) on mRNA and protein level. In contrast, in the apoptosis-resistant cell lines, Bcl-x(L) expression was not affected by UCN-01. Stable overexpression of the Bcl-x(L) protein abrogated UCN-01-triggered apoptosis, but only partially restored growth, indicating that both cell cycle arrest and apoptosis exert the anticancer effect in a coordinated manner. The inhibition of Akt phosphorylation did not correlate with the apoptotic phenotype. UCN-01 inhibited the activating STAT3 phosphorylations on Ser727 and, notably, on Tyr705, but STAT3 did not contribute to Bcl-x(L) expression in colon carcinoma cells. Moreover, we show for the first time that UCN-01 induces apoptosis by suppression of Bcl-x(L) expression. The inhibition of this pathway is a new aspect of cytotoxic and modulatory potential of UCN-01.