Inhibition Of Proliferation And Induction Of Apoptosis By Proteasome Inhibitor MG-132 On U87 Glioma Cell In Vitro

Objective To explore the effects of proteasome inhibitor MG-132 on proliferation and apoptsis of U87 glioma cells in vitro.Methods U87 glioma cells were cultured in vitro with different concentrations of proteasome inhibitor MG-132 (0,2.5,5,10 and 20μmol/L) for12h, 24h, 48h and 72h. The inhibition rates were determined by MTT assay the effect of MG-132 and inverted light microscope and HE stains was used to observe on the morphology change of the cell line U87. Apoptosis and distribution of cell cycle were determined with flow cytometry, Ultrastructure were observed under the electronmicroscope, U87 cells grew with different concentrations (0,2.5,5,10 and 20μmol/L) MG-132 for12h, 24h, 48h and 72h.Results Compared with normal control,Exposure to MG-132 had a antiproliferative effect on U87 glioma cells by MTT,and was in a certain range of time and dose-dependent. After observed by inverted light microscope treated with MG-132,U87 cells had significant morphological changes: U87 cells ecphyma were reduced, density was degrade, cell bodies refraction were weakened. HE stains showed significant apoptosis change in U87 cells treated with MG-132: U87 cells were nucleonic pycnosis,synapse were shorted,density were induced,shrinkage;The rate of apoptosis was increased gradually with the increasing concentration of MG-132 With flow cytometry analysis by a dose-dependent manner. With flow cytometry analysis MG-132 could induce an arrest of cell cycle in G₂/M phase. Morphological changes of MG-132 treated U87 cells were observed by electron microscope. Apoptotic changes, such as shrinkage,nucleonic pycnosis,chromatin margination of nuclear,formation of representative apoptotic bodies, were observed in MG-132 treated group.Conclusion Proteasome inhibitor MG-132 can inhibit U87 glioma cell proliferation and induce U87 glioma cell apoptosis,in a certain range time and dose-dependent manner;In flow cytometry analysis MG-132 could induce an arrest of cell cycle in G₂/M phase.