The human neuroblastoma cell line SK-N-BE can be induced to differentiate by exposure to retinoic acid (RA) or α-difluoromethylornithine (DFMO). RA treatment causes neuronal-like morphologic alterations such as the formation of neurite extensions, 60% reduction of growth rate, enhanced transglutaminase activity, and an increase in putrescine, γ-aminobutyric acid, and acetylcholinesterase levels. Inhibition of ornithine decarboxylase by DFMO severely affects polyamine metabolism, leading to complete growth inhibition and to an antigenic profile, suggesting a melanocytic differentiation of the cells. In both models the acquisition of more differentiated characteristics, paralled by the growth inhibition, suggests the transformation towards a less malignant phenotype. As shown by our previous studies, tumor cells present an altered pattern of the enzymes that scavenge oxygen radicals - superoxide dismutase, catalase, and glutathione peroxidase - when compared to their nonmalignant counterparts. In particular, low levels of H2O2 detoxifying enzymes were detected. The present study examines whether differentiation is able to 'normalize' the balance of the cell antioxidative defences.
|Number of pages||4|
|Journal||Annals of the New York Academy of Sciences|
|Publication status||Published - 1988|
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)