The Experimental Studies Of Inducing Apoptosis By Survivin Gene Silencing In Human Glioma Cells

Part â… The expression of important apoptosis related protein in human gliomas Objective In order to investigate the expression of Survivin, p53, Caspase-3 and Caspase-7 in human glioma tissues,we analysis the correlations of these indexes and the apoptosis, proliferation of tumor cells. Methods 48 cases of gliomas and 18 samples of normal tissues were studied using immunohistochemistry SP method to examine the expression of Survivin, p53, Caspase-3 and Caspase-7. TUNEL technique was used to detect the cell apoptosis phenomenon. Immunohistochemistry SABC method was used to examine the Ki-67 labeling index(Ki-67 LI) of normanl brain tissues and glioma tissues. Results The expression level of Survivin, p53, Caspase-3 and Caspase-7 in gliomas were higher than that of in normal brain tissues significantly(P<0.01). Positive rates were 56.2%, 52.0%, 70.8% and 68.8%, respectively. Along with the rise of glioma grade, the expression level of Survivin and p53 were also upregulated. There was no associativity between the expression level of Caspase-3, Caspase-7 and the grade of gliomas, but the synergistic expression phenomenon was found in Caspase-3 and Caspase-7. In the positive samples of Survivin, p53, Caspase-3 and Caspase-7 were found the apoptosis index(AI) as well as Ki-67 LI was much higher than that of in negative samples(P<0.01). Moreover, followed up the rising of glioma grades, the Ki-67 LI was also increased. Conclusion The expressions of Survivin , p53, Ki-67 LI have a important significance to evaluate the malignant biological behavior of gliomas. Caspase-3 and Caspase-7 may be have some conjoined mechanisms in cell apoptosis. There are a few of uncertainties between apoptosis and proliferations of human glioma tissues. Partâ…¡The effect of specific small interfering RNA on inhibiting the expression of Survivin in human glioma cells Objective Survivin, a member of inhibitor of apoptosis protein (IAP) gene family, expressed in various human cancer tissues, and may facilitate tumor cell evasion from apoptosis, and promote aberrant mitotic progression. This study was to investigate the feasibility of knockdown of Survivin gene with small interfering RNA and to observe the apoptosis in gliomas which was influenced by siRNA. Methods Survivin specific siRNA oligonucleotides were designed and synthesized artificially. This siRNA were transfected into glioma cells to inhibit the expression of Survivin in vitro. mRNA level of Survivin was detected by real-time quantitative polymerase chain reaction (PCR). The apoptosis of cells was assayed by flow cytometry (FCM). Results The expression of Survivin mRNA in siRNA-transfected samples decreased by 92.6%, 89.5% in T98, SF767 cells respectively in 24 hours after transfected with siRNA oligos. The expression amount was declined by 80.1% and 67.6% in 48 hours after RNAi. The apoptosis rate of T98 cells was 50.2% in 24 hours after interfere, and was 38.4% in 48 hours. The apoptosis rate of SF767 cells were 40.1% and 25.6% ,respectively. There was a significant difference between the RNAi cells and negative controls(P<0.01). Conclusion The specific siRNA oligos which targeting Survivin could knockdown the expression of Survivin mRNA, and induce apoptosis in human glioma cells. Partâ…¢The influence of Survivin gene silence on the radiosensitivity of human T98 glioma cells Objective To investigate the changes of radiosensitivity in human T98 glioma cells after Survivin gene silence. Methods Specific siRNA were synthesized artificially. This siRNA were used to inhibit the expression of Survivin gene in T98 cells. Linear accelerator was used to ionize the cells of every groups. Cellular proliferation activities were assayed by tetrazolium bromide(MTT) colorimetry. The apoptosis of cells was assayed by flow cytometry (FCM). Results There was no statistical significance between the apoptosis level of simple ionizing group and that of control group(P>0.05). The average apoptosis rate of T98 cells in RNA interfering group was 45.2% which washigher than that of control group significantly(P<0.01). In the combined group, 10Gy dose of ionizing radiation was exposed to T98 cells after RNA interfering. Then the average apoptosis rate was raised to 74.3% which was higher than that of RNAi group and simple radiation group(P<0.01). The proliferation of T98 cells was inhibited markedly in the combined group of radiation plus RNAi whose MTT OD value were lower than that of RNAi group(P<0.01). There was no apparent changes of MTT OD value between the group of simple radiation and the group of control. Conclusion Survivin gene silence has remarkable radiosensitization in human gioma T98 cells. Partâ…£The effect of apoptosis induction in human glioma T98 cells by specific siRNA of Survivin associated with Gleevec Objective To investigate the effect of the specific siRNA oligonucleotide allied Gleevec in inducing the apoptosis of human glioma cells. Methods The siRNA Oligo were used to interfere the expression f Survivin gene. 0.5umol/L dosage of Gleevec were used to administrate on T98 cells. The apoptosis of cells was assayed by flow cytometry (FCM). Results Gleevec could induce the apoptosis of T98 cells. After 24 hours of administration, The average apoptosis rate was increased to 15.31% which had statistical significance than that of control group (P<0.01). If the same administration based on the RNA interfering in beforehand, the apoptosis rate of T98 cells could be elevated further onwards. The average apoptosis rate could be raised to 68.73% which had statistical significance than that of simple administration group (P<0.01). Conclusion Survivin siRNA oligonucleotide associated with Gleevec could elevate the level of apoptosis in glioma cell greatly.