A molecular study of pathways involved in the inhibition of cell proliferation in neuroblastoma B65 cells by the GSK-3 inhibitors lithium and SB-415286.

Abstract

Pharmacological GSK-3 inhibitors are potential drugs for the treatment of neurodegenerative diseases, cancer and diabetes. We examined the antiproliferative effects of two GSK-3 inhibitors, lithium and SB-415286, on B65 neuroblastoma cell line. Treatment of B65 cells with either drug administered separately caused a decrease in cell proliferation that was associated with G(2)/M cell cycle arrest. Cell-cycle proteins such as cyclins D, E, A, cdk4 and cdk2 were up-regulated. Since lithium and SB-415286-induced G(2)/M arrest we studied changes in the expression of proteins involved in this phase, specifically cyclin B, cdc2 and the phosphorylated form of this protein (tyr15-cdc2). Both drugs increased the expression of tyr15-cdc2, thus inhibiting mitosis. On the other hand, SB-415286 increased the expression of SIRT2, involved in the regulation of proliferation. Moreover, cell-cycle arrest mediated by SB-415286 was accompanied by apoptosis that was not prevented by 100 microM of zVAD-fmk (benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone), a pan-caspase inhibitor. Likewise, GSK-3 inhibitors did not affect the mitochondrial release of apoptosis inducing factor (AIF). We conclude that inhibitors of GSK-3 induced cell-cycle arrest, mediated by the phosphorylation of cdc2 and, in the case of SB-415286, SIRT2 expression, which induced apoptosis in a caspase-independent manner.

• Authors: Javier G Pizarro, Jaume Folch, José Luis Esparza, J Jordan, Mercè Pallàs, Antoni Camins
• Journal: Journal of cellular and molecular medicine (J Cell Mol Med) Vol. 13 Issue 9B Pg. 3906-17 (Sep 2009) ISSN: 1582-4934 [Electronic] England
• PMID: 18624766 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• 3-(3-chloro-4-hydroxyphenylamino)-4-(4-nitrophenyl)-1H-pyrrole-2,5-dione
• Aminophenols
• Apoptosis Inducing Factor
• Cell Cycle Proteins
• Enzyme Inhibitors
• Maleimides
• Sirt2 protein, rat
• Lithium
• CDC2 Protein Kinase
• Cdk1 protein, rat
• Cyclin-Dependent Kinases
• Glycogen Synthase Kinase 3
• Sirtuin 2

Topics

• Aminophenols (pharmacology)
• Animals
• Apoptosis
• Apoptosis Inducing Factor (metabolism)
• CDC2 Protein Kinase
• Cell Cycle (drug effects)
• Cell Cycle Proteins (biosynthesis, metabolism)
• Cell Line, Tumor
• Cell Proliferation
• Cyclin-Dependent Kinases
• Enzyme Inhibitors (pharmacology)
• Glycogen Synthase Kinase 3 (antagonists & inhibitors)
• Lithium (pharmacology)
• Maleimides (pharmacology)
• Neuroblastoma (metabolism)
• Rats
• Sirtuin 2 (biosynthesis)