Anisomycin induces glioma cell death via down-regulation of PP2A catalytic subunit in vitro

Abstract

Aim:To examine the effects of anisomycin on glioma cells and the related mechanisms in vitro.Methods:The U251 and U87 human glioblastoma cell lines were tested. The growth of the cells was analyzed using a CCK-8 cell viability assay. Apoptosis was detected using a flow cytometry assay. The expression of proteins and phosphorylated kinases was detected using Western blotting.Results: Treatment of U251 and U87 cells with anisomycin (0.01-8 mol/L) inhibited the cell growth in time- and concentration-dependent manners (the IC 50 values at 48 h were 0.2330.021 and 0.1920.018 mol/L, respectively). Anisomycin (4 mol/L) caused 21.5%2.2% and 25.3%3.1% of apoptosis proportion, respectively, in U251 and U87 cells. In the two cell lines, anisomycin (4 mol/L) activated p38 MAPK and JNK, and inactivated ERK1/2. However, neither the p38 MAPK inhibitor SB203580 (10 mol/L) nor the JNK inhibitor SP600125 (10 mol/L) prevented anisomycin-induced cell death. On the other hand, anisomycin (4 mol/L) reduced the level of PP2A/C subunit (catalytic subunit) in a time-dependent manner in the two cell lines. Treatment of the two cell lines with the PP2A inhibitor okadaic acid (100 nmol/L) caused marked cell death.Conclusion:Anisomycin induces glioma cell death via down-regulation of PP2A catalytic subunit. The regulation of PP2A/C exression by anisomycin provides a clue to further study on its role in glioma therapy. © 2012 CPS and SIMM.