RESUMEN
Overexpression of RhoA in cancer indicates a poor prognosis, because of increased tumor cell proliferation and invasion and tumor angiogenesis. We showed previously that anti-RhoA small interfering RNA (siRNA) inhibited aggressive breast cancer more effectively than conventional blockers of Rho-mediated signaling pathways. This study reports the efficacy and lack of toxicity of intravenously administered encapsulated anti-RhoA siRNA in chitosan-coated polyisohexylcyanoacrylate (PIHCA) nanoparticles in xenografted aggressive breast cancers (MDA-MB-231). The siRNA was administered every 3 days at a dose of 150 or 1500 microg/kg body weight in nude mice. This treatment inhibited the growth of tumors by 90% in the 150-microg group and by even more in the 1500-microg group. Necrotic areas were observed in tumors from animals treated with anti-RhoA siRNA at 1500 microg/kg, resulting from angiogenesis inhibition. In addition, this therapy was found to be devoid of toxic effects, as evidenced by similarities between control and treated animals for the following parameters: body weight gain; biochemical markers of hepatic, renal, and pancreatic function; and macroscopic appearance of organs after 30 days of treatment. Because of its efficacy and the absence of toxicity, it is suggested that this strategy of anti-RhoA siRNA holds significant promise for the treatment of aggressive cancers.
Asunto(s)
Neoplasias de la Mama/terapia , Quitosano/administración & dosificación , Bombas de Infusión , Trasplante de Neoplasias/normas , ARN Interferente Pequeño/administración & dosificación , Proteína de Unión al GTP rhoA/genética , Animales , Neoplasias de la Mama/irrigación sanguínea , Línea Celular Tumoral , Quitosano/uso terapéutico , Quitosano/toxicidad , Humanos , Ratones , Nanopartículas/administración & dosificación , Nanopartículas/uso terapéutico , Nanopartículas/toxicidad , Trasplante de Neoplasias/métodos , Neoplasias/fisiopatología , Neovascularización Patológica/terapia , ARN Interferente Pequeño/uso terapéutico , ARN Interferente Pequeño/toxicidadRESUMEN
Overexpression of RhoA or RhoC in breast cancer indicates a poor prognosis, due to increased tumor cell proliferation and invasion and tumor-dependent angiogenesis. Until now, the strategy of blockage of the Rho-signaling pathway has used either GGTI or HMG-CoA reductase inhibitors, but they are not specific to RhoA or RhoC inhibition. In this study, a new approach with anti-RhoA and anti-RhoC siRNAs was used to inhibit specifically RhoA or RhoC synthesis. Two transfections of either RhoA or RhoC siRNA (8.5 nM) into MDA-MB-231 human breast cancer cells or HMEC-1 endothelial cells induced extensive degradation of the target mRNA and led to a dramatic decrease in synthesis of the corresponding protein. In vitro, these siRNAs inhibited cell proliferation and invasion more effectively than conventional blockers of Rho cell signaling. Finally, in a nude mouse model, intratumoral injections of anti-RhoA siRNA (100 microl at 85 nM) every 3 days for 20 days almost totally inhibited the growth and angiogenesis of xenografted MDA-MB-231 tumors. One may infer from these observations that specific inhibition of the Rho-signaling pathway with siRNAs represents a promising approach for the treatment of aggressive breast cancers.
Asunto(s)
Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , ARN Interferente Pequeño/metabolismo , Proteínas de Unión al GTP rho/deficiencia , Proteínas de Unión al GTP rho/genética , Proteína de Unión al GTP rhoA/deficiencia , Proteína de Unión al GTP rhoA/genética , Transporte Activo de Núcleo Celular , Animales , Neoplasias de la Mama/irrigación sanguínea , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Núcleo Celular/metabolismo , Proliferación Celular , Colágeno , Proteínas del Citoesqueleto/metabolismo , Regulación hacia Abajo/genética , Combinación de Medicamentos , Inhibidores Enzimáticos/farmacología , Regulación Neoplásica de la Expresión Génica , Humanos , Laminina , Ratones , Invasividad Neoplásica/genética , Invasividad Neoplásica/prevención & control , Neovascularización Patológica , Proteoglicanos , Piridinas/farmacología , Interferencia de ARN , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN Interferente Pequeño/genética , Transactivadores/metabolismo , Transfección , beta Catenina , Proteínas ras , Proteínas de Unión al GTP rho/metabolismo , Proteína de Unión al GTP rhoA/metabolismo , Proteína rhoC de Unión a GTPRESUMEN
Fenofibrate, a peroxisome proliferator-activated receptor (PPAR)-alpha activator, used as a normolipidemic agent, is thought to offer additional beneficial effects in atherosclerosis. Since angiogenesis is involved in plaque progression, hemorrhage, and instability, the main causes of ischemic events, this study was designed to evaluate the action of fenofibrate on angiogenesis. Our results show that fenofibrate (i) inhibits endothelial cell proliferation induced by angiogenic factors, followed at high concentrations by an increase in apoptosis, (ii) inhibits endothelial cell migration in a healing wound model, (iii) inhibits capillary tube formation in vitro, and (iv) inhibits angiogenesis in vivo. Concerning the mechanism of action, the inhibition of endothelial cell migration by fenofibrate can be explained by a disorganization of the actin cytoskeleton. At the molecular level, fenofibrate markedly decreased basic fibroblast growth factor-induced Akt activation and cyclooxygenase 2 gene expression. This inhibition of angiogenesis could participate in the beneficial effect of fenofibrate in atherosclerosis.
Asunto(s)
Fenofibrato/farmacología , Hipolipemiantes/farmacología , Neovascularización Patológica/tratamiento farmacológico , Proteínas Serina-Treonina Quinasas , Actinas/metabolismo , Apoptosis/efectos de los fármacos , Capilares/efectos de los fármacos , Capilares/crecimiento & desarrollo , Ciclo Celular/efectos de los fármacos , Línea Celular , Ciclooxigenasa 2 , Dermis/efectos de los fármacos , Dermis/crecimiento & desarrollo , Endotelio/efectos de los fármacos , Endotelio/crecimiento & desarrollo , Humanos , Técnicas In Vitro , Isoenzimas/biosíntesis , Isoenzimas/genética , Proteínas de la Membrana , Prostaglandina-Endoperóxido Sintasas/biosíntesis , Prostaglandina-Endoperóxido Sintasas/genética , Proteínas Proto-Oncogénicas/efectos de los fármacos , Proteínas Proto-Oncogénicas c-aktRESUMEN
In breast cancers, clinical symptoms of inflammation localised around the tumour at the time of diagnosis have been considered to have poor prognosis significance. In this study, the biological mechanisms responsible for the deleterious action of monocytes in cancer were investigated. The incubation of the breast-cancer-derived MDA-MB231 cells with monocytes resulted in an increase in factors involved in cell invasion (i.e. both cancer cells and monocytes-associated urokinase and Tissue Factor, and PAI-1 and MMP-9 secretion). Moreover, the functions of monocytes were also modified. Incubation of monocytes with MDA-MB231 cancer cells resulted in a downregulation in the secretion of the antiproliferative cytokine Oncostatin M, while the apoptotic factor TNF alpha was dramatically increased. However, MDA-MB231 cancer cells have been shown to be resistant towards the apoptotic action of TNF alpha. These findings demonstrate that incubation of MDA-MB231 cancer cells with monocytes induced a crosstalk, which resulted in an increased expression of factors involved in cancer cell invasiveness and in a modification of monocytes function against cancer cells, while inflammatory effects were increased.
Asunto(s)
Neoplasias de la Mama/fisiopatología , Monocitos/fisiología , Neoplasias de la Mama/patología , Línea Celular Tumoral , Técnicas de Cocultivo , Femenino , Humanos , Metaloproteinasas de la Matriz/sangre , Metaloproteinasas de la Matriz/metabolismo , Monocitos/citología , Oncostatina M , Péptidos/metabolismo , Receptores de Superficie Celular/metabolismo , Receptores del Activador de Plasminógeno Tipo Uroquinasa , Valores de Referencia , Factor de Necrosis Tumoral alfa/metabolismo , Activador de Plasminógeno de Tipo Uroquinasa/metabolismoRESUMEN
During the year 1982 serum cholesterol and apolipoprotein A1 and B levels were measured in 1319 male subjects (mean age 20 years) from different provinces of Belgium. The serum cholesterol level and the apolipoprotein B level were distinctly lower in Dutch-speaking than in French-speaking subjects. An increase of 1.1 mg% of total cholesterol was found per kg per consumer unit per year of butter consumed and a decrease of 1.1 mg% per kg per consumer unit per year of margarine consumed. The higher cholesterol value in French-speaking subjects correlated significantly with a high regional mortality from all causes and from ischaemic heart disease in male subjects of the 45-64-year age group. A 10 mg% difference in serum cholesterol at the age of 20 years corresponds with an increase in mortality from all causes of 20% and from ischaemic heart disease of 21%. A significant difference in log GGT (gamma glutamyl-transpeptidase)--possibly due to differences in alcohol consumption--was observed between the provinces of Belgium. The difference in cholesterol and apolipoprotein B level remained significant after adjustment for log GGT.