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.
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.
Pizarro
Javier G
JG
Unitat de Farmacologia i Farmacognòsia, Facultat de Farmàcia, Institut de Biomedicina and Centros de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, Universitat de Barcelona, Nucli Universitari de Pedralbes, Barcelona, Spain.
Folch
Jaume
J
Esparza
José Luis
JL
Jordan
J
J
Pallàs
Mercè
M
Camins
Antoni
A
D000627:Aminophenols / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis; D051033:Apoptosis Inducing Factor / Q000378:metabolism; D016203:CDC2 Protein Kinase; D002453:Cell Cycle / Q000187:drug effects; D018797:Cell Cycle Proteins / Q000096:biosynthesis* / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D018844:Cyclin-Dependent Kinases; D004791:Enzyme Inhibitors / Q000494:pharmacology; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors*; D008094:Lithium / Q000494:pharmacology*; D008301:Maleimides / Q000494:pharmacology*; D009447:Neuroblastoma / Q000378:metabolism*; D051381:Rats; D056565:Sirtuin 2 / Q000096:biosynthesis*
C417520:3-(3-chloro-4-hydroxyphenylamino)-4-(4-nitrophenyl)-1H-pyrrole-2,5-dione; D000627:Aminophenols; D051033:Apoptosis Inducing Factor; D018797:Cell Cycle Proteins; D004791:Enzyme Inhibitors; D008301:Maleimides; C097475:Sirt2 protein, rat; D008094:Lithium; D016203:CDC2 Protein Kinase; C548796:Cdk1 protein, rat; D018844:Cyclin-Dependent Kinases; D038362:Glycogen Synthase Kinase 3; D056565:Sirtuin 2