DNA microarray analysis reveals metastasis-associated genes in rat prostate cancer cell lines / Análisis de micromatrices de ADN revela genes asociados a metástasis en líneas celulares de cáncer de próstata de rata

Introduction. The molecular and cellular mechanisms involved in prostate cancer progression towards a hormone-independent and highly invasive, metastatic phenotype, are not well understood. Cell lines with different metastatic potential, when analyzed by microarray techniques, offer valuable tools for identifying genes associated with the metastatic phenotype. Objectives. Gene expression profiles were compared for two rat prostate cancer cell lines with differing metastatic abilities in order to better characterized molecular underpinnings of the prostate cancer metastatic process. Materials and methods. Affymetrix arrays were used to analyze gene expression of two rat prostate cancer cell lines, MAT-LyLu and G. Microarray data were analyzed using pathway and functional group analysis. A selected set of genes was subjected to real-time polymerase chain reaction for validating the microarray data. Results. Microarray data analysis revealed differential expression of genes from a number of signaling and metabolic pathways. Overexpression was detected in 48 genes and underexpression in 59 genes of the MAT-LyLu line compared to the standard G line. Genes were grouped into functional categories, including epithelial-extracellular matrix interaction, cell motility, cell proliferation, and transporters, among others. Many of these genes were not previously associated to prostate cancer metastasis. Conclusions. Many genes with altered expression associated with a metastatic prostate cancer phenotype were identified. Further validation of these genes in human prostate samples will determine their usefulness as biomarkers for early diagnosis of recurrence or metastasis of prostate cancer, as well as potential therapeutic targets for this disease.

Introducción. Los mecanismos moleculares y celulares involucrados en la progresión del cáncer de próstata hacia un fenotipo metastásico no son bien entendidos. El análisis molecular de líneas celulares con diferentes potenciales metastásicos ofrece un instrumento valioso para identificar genes asociados al fenotipo metastásico. Objetivos. Comparar los perfiles de expresión genética de dos líneas celulares de cáncer de próstata de rata con diferentes capacidades metastásicas para un mejor entendimiento del proceso metastásico. Materiales y métodos. Se utilizaron micromatrices de Affymetrix para analizar la expresión génica de dos líneas celulares de próstata de rata con diferentes propiedades metastásicas, MAT-LyLu y G. Los datos fueron analizados en el contexto de vías y grupos funcionales. Se utilizó reacción en cadena de la polimerasa en tiempo real para validación de genes seleccionados. Resultados. Además de la expresión diferencial de genes en un número de vías de señalización y metabólicas, se detectó sobre-expresión de 48 genes y expresión disminuida de 59 genes en la línea MAT-LyLu comparado con la línea G. Los genes fueron agrupados en categorías funcionales, tales como interacción epitelial-matriz extracelular, motilidad celular, proliferación celular, y transportadores, entre otros. Muchos de estos genes no han sido asociados previamente a la metástasis del cáncer de próstata. Conclusiones. Se identificaron genes con expresión alterada asociados al fenotipo metastásico del cáncer de próstata. La subsiguiente validación de estos genes en tejido prostático humano pudiera revelar su utilidad como marcadores biológicos para esta enfermedad.

Evidence for the involvement of exposed surface carbohydrates of Agrobacterium tumefaciens in relation to crown gall tumour induction.

The exposed carbohydrate residues on the cell surface of both tumourigenic and nontumourigenic strains of Agrobacterium have been investigated using lectins as probes. N-acetyl-D-galactosamine and β-D-galactose were found to be present as the exposed groups on the cell surfaces of he Agrobacterium strains. These carbohydrate residues are attached to lipids on the outer membrane of the bacteria as lipopolysaccharides. Fluorescently labelled lectins were used to observe bacterial agglutination in fluorescence microscope. The involvement of these exposed carbohydrate groups in host-pathogen interaction was demonstrated by actual inhibition of tumour initiation at wound sites on host plant.