RESUMEN
Malignant transformation is associated with changes in the glycosylation of cell surface proteins and lipids. In tumor cells, alterations in cellular glycosylation may play a key role in their metastatic behaviour. In the present study, we have assessed the relationship between cell surface oligosaccharides and the metastasis ability of mouse mammary tumor cell lines 67NR and 4TO7. The cell surface oligosaccharides have been analyzed using specific binding assays with some plant lectins and the metastasis ability has been studied using transwell migration and invasion assays. In addition, we investigated the role of terminal sialic acids in the metastatic potential (cell adhesion on fibronectin, cell migration and invasion) in the 4TO7 cells on treatment with neuraminidase. The cell lines used in study have different metastasis abilities in vivo - the 67NR form primary tumors, but no tumor cells are detectable in any distant tissues, while cells of the 4TO7 line are able to spread to lung. In vitro metastasis experiments have revealed higher ability of adhesion, cell migration and invasion in the 4TO7 cells than the 67NR cells. Specific lectins binding assays show that the 4TO7 cells expressed more high-mannose type, multi-antennary complex-type N-glycans, beta-1,6-GlcNAc-branching, alpha-2,6-linked sialic acids, N-acetylgalactosamine and galactosyl(beta-1,3)-N-acetylgalactosamine. Removal of sialic acids on treatment with neuraminidase decreases adhesion, but increases the migration and has shown no significant change in the invasion ability of the 4TO7 cells. The study suggests that the sialic acids are not crucial for the cell migration and invasion in the 4TO7 cells. The findings provide the new insights in understanding the role of cell surface oligosaccharides in cancer metastasis.
Asunto(s)
Animales , Adhesión Celular , Línea Celular Tumoral , Membrana Celular/metabolismo , Movimiento Celular , Células , Glicosilación , Lectinas/química , Neoplasias Mamarias Animales/metabolismo , Ratones , Invasividad Neoplásica , Metástasis de la Neoplasia , Oligosacáridos/química , Polisacáridos/química , Ácidos Siálicos/químicaRESUMEN
Se determinó la concentración de ácidos siálicos séricos en 30 personas del sexo masculino aparentemente sanas entre 55 y 75 años de edad y en 80 del sexo femenino cuyas edades estaban entre 50 y 75 años. Lasmuestras de suero se obtuvieron de personas del Hogar Central Iganacia Rodolfo Vda de Canevaro. El método usado para la cuantificación fue el de Ayala, Moore y Hess. En los varones, los ácidos siálicos alcanzan una media de 53,76ñ0,881 mg por ciento y valores extremos de 42-63 mg por ciento. En las mujeres, la media fue 54,08ñ0,639 por ciento y valores extremos de 42-68 mg por ciento.