RESUMEN
BACKGROUND/AIM: High expression level of Wilm's tumor gene (WT1) in several types of tumors appears to confer disruption of apoptosis and resistance to chemotherapeutic drugs, and correlate with poor outcome. The aim of this work was to determine if down-regulation of WT1 expression results in decreased cell proliferation and the increased action of different types of drugs, both in vitro in B16F10 cells, and in vivo in C57BL/6 mice. MATERIALS AND METHODS: Inhibition of cell proliferation by short hairpin RNA against WT1 (shRNA-WT1), cisplatin, and gemcitabine in B16F10 cells in vitro was determined by the MTT assay and analysis of clonogenic survival. The apoptosis rate was determined by flow cytometry for annexin-V- fluorescein isothiocyante and propidium iodide. RESULTS: Compared to treatment with shRNA-WT1 alone, treatment with shRNA-WT1 in combination with drugs had a synergistic inhibitory effect on B16F10 cell proliferation, particularly for the combination of cisplatin and gemcitabine at their 25% cytotoxic concentrations in vitro. Furthermore, mice treated with shRNA-WT1 in combination with cisplatin and gemcitabine were protected in the same way as those treated with the drugs alone, but were in better physical condition. CONCLUSION: Decreased WT1 expression induces cell death and potentiates the action of anticancer drugs by inducing synergistic effects both in vitro and in vivo, which may be an attractive strategy in lung cancer therapy.
Asunto(s)
Antineoplásicos/farmacología , Cisplatino/farmacología , Desoxicitidina/análogos & derivados , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/secundario , ARN Interferente Pequeño/genética , Proteínas WT1/genética , Animales , Apoptosis/efectos de los fármacos , Apoptosis/genética , Desoxicitidina/farmacología , Femenino , Citometría de Flujo , Expresión Génica , Silenciador del Gen , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/terapia , Melanoma Experimental , Ratones , Carga Tumoral , Proteínas WT1/metabolismo , GemcitabinaRESUMEN
Sulphated polysaccharides (SP) extracted from seaweeds have antiviral properties and are much less cytotoxic than conventional drugs, but little is known about their mode of action. Combination antiviral chemotherapy may offer advantages over single agent therapy, increasing efficiency, potency and delaying the emergence of resistant virus. The paramyxoviridae family includes pathogens causing morbidity and mortality worldwide in humans and animals, such as the Newcastle Disease Virus (NDV) in poultry. This study aims at determining the antiviral activity and mechanism of action in vitro of an ulvan (SP from the green seaweed Ulva clathrata), and of its mixture with a fucoidan (SP from Cladosiphon okamuranus), against La Sota NDV strain. The ulvan antiviral activity was tested using syncytia formation, exhibiting an IC50 of 0.1 µg/mL; ulvan had a better anti cell-cell spread effect than that previously shown for fucoidan, and inhibited cell-cell fusion via a direct effect on the F0 protein, but did not show any virucidal effect. The mixture of ulvan and fucoidan showed a greater anti-spread effect than SPs alone, but ulvan antagonizes the effect of fucoidan on the viral attachment/entry. Both SPs may be promising antivirals against paramyxovirus infection but their mixture has no clear synergistic advantage.
Asunto(s)
Antivirales/farmacología , Virus de la Enfermedad de Newcastle/efectos de los fármacos , Polisacáridos/farmacología , Algas Marinas/química , Acoplamiento Viral/efectos de los fármacos , Animales , Aves , Fusión Celular , Supervivencia Celular/efectos de los fármacos , Chlorocebus aethiops , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Enfermedad de Newcastle/prevención & control , Enfermedad de Newcastle/virología , Phaeophyceae/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Espectrofotometría Infrarroja , Células Vero , Proteínas Virales/efectos de los fármacosRESUMEN
El VIH es el agente etiológico del síndrome de la inmunodeficiencia adquirida o SIDA y el HTLV-1 se ha asociado a la leucemia/linfoma de las células T de adultos y a la paraparesis espástica tropical. En México existe poca información sobre la incidencia de la infección por HTLV-1. En el presente trabajo buscamos la presencia de anticuerpos dirigidos contra HTLV-1 en 100 sueros de pacientes de alto riesgo para la infección por VIH, del área de Monterrey, N. L. En 93 sueros se detectaron anticuerpos anti VIH y dos dieron resultados indeterminados por inmunoelectrotransferencia. Tres sueros VIH positivos dieron también positiva la prueba de aglutinación para HTLV-1; sin embargo, en la prueba confirmatoria de inmunoelectrotransferencia, las tres muestras resultaron negativas para HTLV-1