RESUMEN
Redox adaptation is an important concept that explains the mechanisms by which cancer cells survive under persistent endogenous oxidative stress and become resistant to certain anticancer agents. To investigate this concept, we determined the expression levels of peroxiredoxins (Prxs), antioxidant enzymes in drug-resistant non-small cell lung carcinoma cells. Prx II was remarkably increased only in A549/GR (gefitinib-resistant) cells compared with A549 cells, consistent with methylation/demethylation. Prx II was highly methylated in the A549 cells but was demethylated in the A549/GR cells. The elevated expression of Prx II resulted in the downregulation of reactive oxygen species (ROS) and cell death and upregulation of cell cycle progression in the A549/GR cells. When Prx II mRNA in the A549/GR cells was knocked down, the levels of ROS and apoptosis were significantly recovered to the levels of the controls. In addition, signaling molecules involved in apoptosis were increased in the A549/GR-shPrx II cells. There was no difference in the expression of MAPK/ERK between the A549/GR cells and A549/GR-shPrx II cells, but the phosphorylation of JNK was increased in the A549/GR cells and was markedly decreased in the A549/GR-shPrx II cells. Colony number and tumor growth were significantly decreased in the A549/GR-shPrx II cells compared with the A549/GR cells. Our findings suggest that Prx II has an important role in cancer cell survival via the modulation of signaling molecules involved in apoptosis and the phosphorylation of JNK by the downregulation of ROS levels in A549/GR cells.
Asunto(s)
Animales , Femenino , Humanos , Antineoplásicos/uso terapéutico , Apoptosis/efectos de los fármacos , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Línea Celular Tumoral , Resistencia a Antineoplásicos , Pulmón/efectos de los fármacos , Neoplasias Pulmonares/tratamiento farmacológico , Ratones Endogámicos BALB C , Ratones Desnudos , Estrés Oxidativo/efectos de los fármacos , Peroxirredoxinas/genética , Quinazolinas/uso terapéutico , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Redox adaptation is an important concept that explains the mechanisms by which cancer cells survive under persistent endogenous oxidative stress and become resistant to certain anticancer agents. To investigate this concept, we determined the expression levels of peroxiredoxins (Prxs), antioxidant enzymes in drug-resistant non-small cell lung carcinoma cells. Prx II was remarkably increased only in A549/GR (gefitinib-resistant) cells compared with A549 cells, consistent with methylation/demethylation. Prx II was highly methylated in the A549 cells but was demethylated in the A549/GR cells. The elevated expression of Prx II resulted in the downregulation of reactive oxygen species (ROS) and cell death and upregulation of cell cycle progression in the A549/GR cells. When Prx II mRNA in the A549/GR cells was knocked down, the levels of ROS and apoptosis were significantly recovered to the levels of the controls. In addition, signaling molecules involved in apoptosis were increased in the A549/GR-shPrx II cells. There was no difference in the expression of MAPK/ERK between the A549/GR cells and A549/GR-shPrx II cells, but the phosphorylation of JNK was increased in the A549/GR cells and was markedly decreased in the A549/GR-shPrx II cells. Colony number and tumor growth were significantly decreased in the A549/GR-shPrx II cells compared with the A549/GR cells. Our findings suggest that Prx II has an important role in cancer cell survival via the modulation of signaling molecules involved in apoptosis and the phosphorylation of JNK by the downregulation of ROS levels in A549/GR cells.
Asunto(s)
Animales , Femenino , Humanos , Antineoplásicos/uso terapéutico , Apoptosis/efectos de los fármacos , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Línea Celular Tumoral , Resistencia a Antineoplásicos , Pulmón/efectos de los fármacos , Neoplasias Pulmonares/tratamiento farmacológico , Ratones Endogámicos BALB C , Ratones Desnudos , Estrés Oxidativo/efectos de los fármacos , Peroxirredoxinas/genética , Quinazolinas/uso terapéutico , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Currently, several assays can confirm acute dengue infection at the point-of-care. However, none of these assays can predict the severity of the disease symptoms. A prognosis test that predicts the likelihood of a dengue patient to develop a severe form of the disease could permit more efficient patient triage and treatment. We hypothesise that mRNA expression of apoptosis and innate immune response-related genes will be differentially regulated during the early stages of dengue and might predict the clinical outcome. Aiming to identify biomarkers for dengue prognosis, we extracted mRNA from the peripheral blood mononuclear cells of mild and severe dengue patients during the febrile stage of the disease to measure the expression levels of selected genes by quantitative polymerase chain reaction. The selected candidate biomarkers were previously identified by our group as differentially expressed in microarray studies. We verified that the mRNA coding for CFD, MAGED1, PSMB9, PRDX4 and FCGR3B were differentially expressed between patients who developed clinical symptoms associated with the mild type of dengue and patients who showed clinical symptoms associated with severe dengue. We suggest that this gene expression panel could putatively serve as biomarkers for the clinical prognosis of dengue haemorrhagic fever.
Asunto(s)
Humanos , Antígenos de Neoplasias/genética , Cisteína Endopeptidasas/genética , Glicoproteínas de Membrana/genética , Proteínas de Neoplasias/genética , Peroxirredoxinas/genética , Receptores de IgG/genética , Receptores de Interleucina-1/genética , Índice de Severidad de la Enfermedad , Dengue Grave/diagnóstico , Proteínas Reguladoras de la Apoptosis/genética , Biomarcadores , Expresión Génica , Proteínas Ligadas a GPI/genética , Inmunidad Innata/genética , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/patología , Análisis por Micromatrices , Pronóstico , Reacción en Cadena en Tiempo Real de la Polimerasa , ARN Mensajero/aislamiento & purificación , SerotipificaciónRESUMEN
In most part of the world detection of cysts and trophozoites of Entamoeba is based on morphological structure of this species in stool sample by microscopy. However, microscopic examination is unable to distinguish between similar morphological protozoa such as Entarnoeba histolytica and Entamoeba dispar. A simple and cost-effective method is needed in medical laboratories for detection and differentiation of these two species. Stool samples of patients who were referred from health care centers were examined by direct microscopy and trichrome stain. Polymerase chain reaction [PCR] utilizing pEd30F and pEd21AS primers from Peroxiredoxin gene, was used for differentiation of E. histolytica and E. dispar. Genomic DNA from samples was amplified by these primers. The fragment under 100 bp was related to E. histolytica and in contrast the fragment above the 100 bp was related to E. dispar. In this study from 22 microscopic positive samples, E. histolytica was observed only in one patient and E. dispar was detected in the other 21 samples. The result of this study indicate that the PCR reaction could amplify E. dispar and E. histolytica with just one primer pair and this is a cost-effective method for distinguishing between these two species