Effects of memantine on the growth and protein profiles of neuroblastoma cells

Abstract

Objective: Memantine, a low-affinity N-methyl-D-aspartate receptor antagonist, is one of the primary pharmacological therapies for Alzheimer's disease. To explore novel actions of memantine, we analyzed effects of memantine on cell viability, cell growth, and protein profile of neuroblastoma cells. Methods: A human neuroblastoma cell line of GIMEN was used. GIMEN cells were cultured in the presence or absence of 1-100 µM memantine for 48 hours. Effects of memantine on the cell viability and growth were evaluated by counting cell numbers. Proteins, extracted from GIMEN cells treated or non-treated with 10 µM memantine, were separated by 2 dimensional-differential image gel electrophoresis (2D-DIGE). Protein spots of interest were subjected to protein identification by mass spectrometry. Results: The viability of GIMEN cells was 99.0% or more in the range of 1-10 µM memantine compared to that in the absence of memantine. The viability was slightly decreased in the presence of 100 µM memantine (97.5%, p<0.01). In contrast, the cell growth was suppressed by memantine in a dose-dependent manner (2-100 µM, 85.5-63.0%; 2-10 µM, p<0.05; 20-100 µM, p<0.01). For the protein profile analysis, we used GIMEN cells treated with 10 µM memantine which showed the viability of 99.4% and the growth of 76.1%. As a result, 892 protein spots were detected in the 2D-DIGE results of 10 µM memantine-treated and non-treated GIMEN cells. 13 protein spots showed 1.2-fold or higher intensity and 19 protein spots showed-1.2 (1/1.2)-fold or lower intensity in the memantine-treated cells than in the non-treated cells (p<0.05). We identified proteins in 7 out of the 32 spots: coronin-1C (1.44-fold increased), β-actin (-1.21-fold decreased), γ-enolase (-1.21-fold decreased), glutathione synthetase (-1.28-fold decreased), spermatogenesis-associated protein 24 (-1.46-fold decreased), and V-set transmembrane domain-containing protein 2B (-1.46-fold decreased). Interestingly, β-actin, γ-enolase, and glutathione synthetase are known to be involved in cell proliferation. Conclusion: Memantine suppressed the growth of GIMEN cells and affected their protein profiles. Our data suggested a novel action of memantine to suppress the neuroblastoma cell growth, which may be associated with the decreased expression of β-actin, γ-enolase, and glutathione synthetase.