Effects of polyphyllin Ⅵ on the proliferation and apoptosis of glioma cells and potential mechanism / 中国药房

OBJECTIVE To investigate the effects of polyphyllin Ⅵ（PPⅥ） on the proliferation and apoptosis of glioma cells and potential mechanism. METHODS Using human glioma LN229 cells as objects， MTT assay was used to detect the survival rate after treated with different concentrations of PPⅥ [0 （control group）， 1， 2， 4， 8， 16， 32， 64 μmol/L] for different time （24， 48， 72 h）. The clone formation experiments were adopted to detect the number of cell clones and clone formation rate after being treated with different concentrations of PPⅥ [0 （control group）， 2， 4， 8 μmol/L] for 14 days. The flow cytometry and Western blot assay were used to detect the apoptotic rate of cells， the expressions of apoptosis-related protein [B cell lymphoma-2 （Bcl-2）， Bcl-2 associated X protein （Bax）， cleaved caspase-3]， and the expressions of related proteins of Fas/Fas ligand （FasL） death receptor pathway and protein kinase B （Akt）/glycogen synthesis kinase-3β （GSK-3β） pathway after being treated with different concentrations of PPⅥ [0（control group）， 4， 8 μmol/L] for 24 h. RESULTS Compared with the control group， the survival rate of cells， the number of clones and clone formation rate， the protein expression of Bcl-2， and the phosphorylation levels of Akt and GSK-3β protein were decreased significantly in different concentration groups of PPⅥ （P＜0.05 or P＜0.01）. The apoptotic rate， the protein expressions of Bax， cleaved caspase-3， Fas， FasL and cleaved caspase-8 were increased significantly （P＜0.05 or P＜ 0.01）. CONCLUSIONS PPⅥ can inhibit the proliferation and induce the apoptosis of human glioma LN229 cells， which may be related to the activation of the Fas/FasL death receptor pathway and the inhibition of the Akt/GSK-3β pathway.

Influence of Bufalin on the Growth and Proliferation of Human Glioma Cell Line U251 / 中国药师

Objective:To explore the effects of Bufalin on the growth and proliferation of human glioma cells U251. Methods:Methyl thiazolyl tetrazolium(MTT)assay was used to detect the effect of Bufalin on the proliferation of human glioma cells U251. An in-verted microscope was used to observe the changes of cell number,morphology and activity. AnnexinV/ PI was used to measure the in-duction of cell apoptosis caused by Bufalin. Results:Bufalin at different concentrations(0. 001 - 10. 0μmol·L - 1 )inhibited the pro-liferation of U251 cells in a dose and time-dependent manner. Compared with that of the control group,the apoptosis rate of Bufalin group was increased significantly(P < 0. 01). Conclusion:Bufalin can inhibit the growth and proliferation of U251 cells in a dose and time-dependent manner,and induce the apoptosis of U251 cells.

DAPT suppresses the proliferation of human glioma cell line SHG-44

OBJECTIVE@#To explore the suppressing effect of γ-secretase inhibitor DAPT on proliferation of human glioma cell line SHG-44 in vitro and its mechanism.@*METHODS@#The SHG-44 cell was treated by DAPT with different concentration. The proliferation of cells was detected by MTT assay; cell cycle and TSC of CD133(+) were determined by flow cytometry analysis technique; the key factor in Notch signaling pathway (Notch-1, Delta-1, Hes-1) was measured by reverse transcriptase-polymerase chain reaction and western blotting.@*RESULTS@#DAPT inhibited the growth and proliferation of SHG-44 cells significantly(P<0.05). And the inhibiting effect on SHG-44 cells produced by DAPT showed a dose-dependent manner. DAPT increased the rate of cells in G0/G1 phase of SHG-44 cells, while it decreased the rate of cells in S phase. TSC of CD133(+) was significantly reduced after DAPT treated SHG-44 cells. The expression of protein and mRNA of Notch-1, Delta-1 and Hes-1 were gradually downregulated with the increase of DAPT doses.@*CONCLUSIONS@#DAPT can downregulate these key factor in Notch signaling pathway, reduce the TSC of CD133+ and inhibit the proliferation of SHG-44 cells.

Invasion ability and collagenolytic activity of human glioma cells in vitro / 吉林大学学报(医学版)

Objective To investigate the invasion ability and collagenolytic activity of human glioma cells in vitro.Methods Boyden chamber invasion assay was employed to evaluate the cell migration ability of human malignant glioma cell line U87MG in vitro and the effect of conditioned medium of U87MG cells on matrix collagenolytic activity was tested by agar-gelatin gel.Results The number of U87MG glioma cells migrating through the Matrigel-coated membrane was more than that of addition of EDTA or anti-MMP-2 antibody in U87MG glioma cells(P0.05).EDTA or anti-MMP-2 antibody markedly inhibited the number of the migrated cells,the inhibitory rates were 79.2% and 77.1%,respectively. The conditioned medium collected from the U87MG cells showed an increase in the transparent ring area on agar-gelatin gel.Inhibition of MMP-2 enzymatic activity by EDTA or anti-MMP-2 antibody reduced the transparent ring area on agar-gelatin gel.Conclusion Both invasion ability and collagenolytic activity of U87MG cells are depended on MMP-2,suggesting that MMP-2 plays an important role in glioma invasiveness.

Effect of curcumin on the activity of ATPase in U-251 cells / 重庆医科大学学报

Objective:To study the effects of curcumin on the activity of ATPase and the mechanism of apoptosis in U-251 cell.Methods:U-251 cells were treated with 20,40,80,100?mol/L curcumin for 24 h and the growth inhibition rates of U-251 cells were measured with MTT method.Cell apoptosis was inspected with flow cytometry(FCM).The activities of ATPase were determined by colorimetry method.Results:Curcumin inhibited the proliferation of U-251 cells and induced apoptosis of U-251 cells.level of ATPase in U-251 plasma Membrane was low remarkably.Conclusion:Curcumin induced apoptosis and inhibited proliferation of U-251 cell via inhibition of activation of plasma Membrane ATPase.

Curcumin induces U251 cell apoptosis via alteration of expression of FAK and activation of caspase / 中国药理学通报

Aim To study the mechanism of curcumin induced U251 cell apoptosis. Methods U251 cells were treated with 20～100?mol?L~ -1 curcumin for 24 h and the growth inhibition rates of U251 cells were measured with MTT method. MTT method was used to measure the caspase inhibitors effect on curcumin too. Cell apoptosis was inspected with flow cytometry (FCM) and observed using electron microscope. The protein levels of FAK in U251 cells were observed by SP immunocytochemistry. The activity of caspase-3 was measured by spectrofluorometry. Results Curcumin inhibited the proliferation of U251 cells,induced apoptosis of U251 cells. At the same time the protein levels of FAK in U251 cells decreased and the activity of caspase-3 increased significantly. The apoptosis of U251 cells was partially reversed by caspase inhibitors. Conclusion Curcumin induced apoptosis via inhibition of expression of FAK and activation of caspase-3.

IMMUNOFLUORESCENCE STUDY OF THE CYTOSKELETON OF A HUMAN GLIOMA CELL LINE BT_(325) / 解剖学报

The cytoskeleton of BT_(325), a human glioma cell line, was studied by immunofluorescence microscopy. The effects of different fixatives and buffers on microtubules, microfilaments and intermediate filaments were also compared. It was observed that besides microtubules and microfilaments all cells expressed vimentin. However, only a small fraction of the cells were GFAP positive. We conclude that vimentin is the main component of the intermediate filaments in BT_(325) cells. It was also observed that methanol fixation and formaldehyde fixation followed by acetone or Triton X-100 treatment gave rise to satisfactory results for microtubule immune-staining, and methanol or acidic alcohol fixation resulted in bright staining of intermediate filaments. Formaldehyde fixation also resulted in excellent staining for mierotubnles, but weaker staining for intermediate filaments.If the cells were immune-stained after treatment with Triton X-100, the composition of the buffers had profound effects on microtubules and intermediate filaments, but less effects on microfilaments.It was also observed that if Triton-treated ceils were fixed with formaldehyde before immunostaining with monoclonal antibodies to vimentin, the staining was very weak. However, if the ceils were immunostained first and then fixed with for-maldehyde the staing was quite bright. We conclude that for-maldehyd e fixation may "mask" or destroy certain epitopes on vimentin molecules.