RESUMEN
Bromodomain 4 (BRD4) is an epigenetic regulator that, when inhibited, has anti-cancer effects. In this study, we investigated whether BRD4 could be a target for treatment of human hepatocellular carcinoma (HCC). We show that BRD4 is over-expressed in HCC tissues. Suppression of BRD4, either by siRNA or using JQ1, a pharmaceutical BRD4 inhibitor, reduced cell growth and induced apoptosis in HCC cell lines while also slowing HCC xenograft tumor growth in mice. JQ1 treatment induced G1 cell cycle arrest by repressing MYC expression, which led to the up-regulation of CDKN1B (P27). JQ1 also de-repressed expression of the pro-apoptotic BCL2L11 (BIM). Moreover, siRNA knockdown of BIM attenuated JQ1-triggered apoptosis in HCC cells, suggesting an essential role for BIM in mediating JQ1 anti-HCC activity.
Asunto(s)
Azepinas/farmacología , Proteína 11 Similar a Bcl2/metabolismo , Carcinoma Hepatocelular/prevención & control , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Neoplasias Hepáticas/prevención & control , Proteínas Nucleares/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-myc/metabolismo , Factores de Transcripción/antagonistas & inhibidores , Triazoles/farmacología , Animales , Apoptosis/efectos de los fármacos , Proteína 11 Similar a Bcl2/genética , Western Blotting , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , Proteínas de Ciclo Celular , Proliferación Celular/efectos de los fármacos , Inmunoprecipitación de Cromatina , Citometría de Flujo , Humanos , Técnicas para Inmunoenzimas , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Ratones , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , ARN Mensajero/genética , ARN Interferente Pequeño/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND: Previous studies have shown that oncosis in malignant tumors might be related to cellular energy supply. The aim of this study was to detect oncosis in human esophageal squamous cell carcinoma (ESCC), and to investigate its relationship with apoptosis and microvessel density (MVD). METHODS: ESCC specimens were obtained from 30 patients with ESCC after surgery. Transmission electron microscopy, TUNEL, and immunohistochemistry were used to detect oncosis, apoptosis, and MVD. The relation of oncosis to apoptosis and MVD was analyzed by ANOVA, t test, and q test using SPSS 10.0. RESULTS: Transmission electron microscopy revealed both oncosis and apoptosis in the ECSS tissues. About 10% of the TUNEL-positive cells, which were considered apoptotic cells, showed the characteristics of oncosis. In the areas, where oncotic cells accumulated, apoptotic cells were rare; contrarily, where apoptotic cells gathered, oncotic cells were sparse. Compared with the tissues with a high MVD, the number of oncotic cells was increased and that of apoptotic cells was decreased in the tissues with a low MVD. CONCLUSIONS: Cellular oncosis can be detected in human ESCC tissues. The distribution of oncotic cells presents a close relationship with cellular apoptosis and MVD. Oncosis might be induced by poor blood supply.
Asunto(s)
Apoptosis , Carcinoma de Células Escamosas/irrigación sanguínea , Carcinoma de Células Escamosas/patología , Muerte Celular , Neoplasias Esofágicas/irrigación sanguínea , Neoplasias Esofágicas/patología , Anciano , Femenino , Humanos , Etiquetado Corte-Fin in Situ , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND: Studies have shown that oxidized low density lipoprotein (ox-LDL) promotes the pathogenesis and development of atherosclerosis (AS), and that the proliferation, migration and phenotype alteration of vascular smooth muscle cells (vSMCs) into foam cells are critical changes in AS. It is proposed that ox-LDL might play a novel role in the pathologic process of vSMCs. The present study was performed ex vivo to investigate the effects of ox-LDL on the growth of cultured human vSMCs. METHODS: Using NaBr density gradient centrifugation, LDL from human plasma was isolated and purified. ox-LDL was produced from LDL after being incubated with CuSO4. ox-LDL was then added to the culture medium at different concentrations (25 microg/ml, 50 microg/ml, 75 microg/ml, 100 microg/ml, 125 microg/ml, and 150 microg/ml) for 7 days. The influence of ox-LDL on vSMC growth was observed from several aspects as growth curve, mitosis index, lipid staining, and in situ determination of apoptosis. The digital results were analyzed with SPSS 10.0. RESULTS: The ox-LDL produced ex vivo had a good purity and optimal oxidative degree, which was similar to the intrinsic ox-LDL in atherosclerotic plaque. ox-LDL at a concentration of 25 microg/ml demonstrated the strongest proliferation. At the concentration of 125 microg/ml, ox-LDL suppressed the growth of vSMCs. At concentrations of 25 microg/ml and 50 microg/ml, ox-LDL presented powerful mitotic trigger. When the concentration of ox-LDL increased, the mitotic index of vSMCs decreased gradually. ox-LDL induced more foam cells from vSMCs with rich intracellular lipid accumulation at concentrations of 25 microg/ml and 50 microg/ml. ox-LDL at higher concentrations induced more apoptotic vSMCs. CONCLUSIONS: ox-LDL at lower concentrations may trigger proliferation and phenotype alteration into foam cells of vSMCs, and at higher concentrations it may induce apoptosis in vSMCs. ox-LDL plays an important role in the pathogenesis and development of atherosclerosis by its effect on vSMCs proliferation, phenotype alteration and apoptosis.