Inhibitory Effect And Mechanism Of Arsenic Trioxide On Human Glioma Stem Cells

Objective: To study the inhitory effect and its mechanism of arsenic trioxide on human glioma stem cells.Methods: Cell proliferation of As2O3 (3, 6, 12μmo/L) on human glioma stem cells was determined by MTT assay. The morphological changes were observed by Hoechst33258 fluorochrome staining and electron microscope; Cell cycle and apoptosis rate were analysed by flow cytometry. The levels of JNK pathway-mediated MLK3/p-MLK3, c-jun/p-c-jun and Fas/FasL involved in the effect of As2O3 on human glioma stem cells were studied by western blot.Results:(1). MTT assay showed that As2O3 had a significant anti-proliferation effect on human glioma stem cells in a dose-dependant and time-dependant manner. After treated with 6μmo/L As2O3 for 24 h, 48 h, 72 h the inhibition rates were 9.43 %,35.80 % and 50.40 %, respectively; After treated with 12μmo/L As2O3 for 24 h, 48 h, 72 h the inhibition rates were 21.88 %,45.47 % and 63.10 %, respectively.(2). Apoptosis morphological changes about chromatic agglutination and nuclear condensation were detected by Hoechst 33258 fluorochrome staining and electron microscope in As2O3 treated human glioma stem cells.(3). Apoptosis rates of human gioma stem cells treated with 0, 6, 12μmo/L As2O3 for 48 hours were 3.1 %, 12.07 %, 29.53 %, respectively; After trated with As2O3 for 72 h , the apoptosis rates were 3.9 %, 42.74 % and 66.48 % respectively (P<0.05). Cell cycle arrest was examined by Flow Cytometry (FCM). After treated with 6μmo/L As2O3 for 24h, 48h, 72h, the G1 phase rates were 64.184 %,74.790 %,88.467 %, respectively. It was 52.153 % in control group.(4). After treated with 6μmo/L As2O3 for 12h, 24h, 48h the JNK/Fas mediated proteins MLK3/p-MLK3, c-jun/p-c-jun and Fas/FasL were upregulated by western blot. When the cells were treated with 3,6μmo/L As2O3, the MLK3/p-MLK3, c-jun/p-c-jun proteins were also upregulated.Conclusion: The results suggested that As2O3 could inhibit the proliferation viability of human glioma stem cells (CD133+). It induced cell apoptosis and blocked the cell cycle at G1 phase. The molecule mechanisms may be associated with the activation of JNK/Fas pathway.