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目的:观察碘-125(125I)粒子对体外培养的人脑恶性胶质瘤细胞系SHG-44的生长抑制及诱导细胞程序性死亡作用,阐明此过程中相关基因的作用机制。方法:人脑恶性胶质瘤细胞株SHG-44,根据应用125I粒子剂量不同分为对照组与处理组,采用四甲基偶氮唑蓝(MTT)法检测125I粒子对SHG-44细胞增殖率的影响;用电镜和原位凋亡检测法(TUNEL)及流式细胞仪、吖啶噔/溴乙啶双荧光染色检测细胞程序性死亡改变,应用基因芯片技术筛选出处理前后与细胞程序性死亡有关的表达差异有统计学意义的基因。结果:125I粒子作用于体外培养的SHG-44胶质瘤细胞,产生了剂量、时间依赖性的增殖抑制作用。MTT比色法检测,经125I粒子处理的SHG-44人胶质瘤细胞,随放射剂量的增加和作用时间的延长,A值明显降低。经2粒125I粒子作用3d(累积剂量86.8MBq)抑制率约为50%,与对照组比较差异有显著性(P<0.05)。透射电镜下观察到处理后SHG44胶质瘤细胞中频繁细胞自噬现象。流式细胞仪检测,S期细胞数在作用后逐渐减少,而G1期和G2/M期细胞比例显著增加。虽然细胞中凋亡细胞的比例随时间的延长有所增加,但比例未超过2%。筛选出SHG-44胶质瘤细胞在125I粒子作用前后差异表达且与程序性死亡相关的基因共56条(上调36条,下调20条)。结论:125I粒子以剂量、时间依赖性方式通过细胞程序性死亡来抑制胶质瘤细胞的增殖,促进细胞向凋亡方向转化;125I粒子诱导下的细胞系中还存在非凋亡调控的细胞程序性死亡(自噬);胶质瘤细胞凋亡过程中相关基因p53/ATM通路的基因、c-myc家族、p16、Bcl-2家族等参与诱导胶质瘤细胞程序性死亡的发生机制。
OBJECTIVE: To observe the effect of iodine-125 (125I) particles on the growth inhibition and induction of programmed cell death in human glioblastoma cell line SHG-44 cultured in vitro and to elucidate the mechanism of action of related genes in this process. METHODS: Human glioblastoma cell line SHG-44 was divided into control group and treatment group according to the dose of 125I particles. The proliferation rate of SHG-44 cells was detected by MTT assay The changes of apoptosis were detected by electron microscopy, TUNEL, flow cytometry and acridine / ethidium bromide staining. The gene chip technique was used to screen the changes of cell apoptosis There were statistically significant differences in the expression of death-related genes. RESULTS: The 125I particles acted on SHG-44 glioma cells cultured in vitro with a dose-dependent and time-dependent inhibition of proliferation. MTT colorimetric assay, 125I particle-treated SHG-44 human glioma cells, with a dose increase and the role of prolonged time, A value was significantly lower. The inhibition rate of 2 125I particles for 3d (cumulative dose 86.8MBq) was about 50%, which was significantly different from that of the control group (P <0.05). Transmission electron microscopy was observed in SHG44 glioma cells after treatment of frequent cell autophagy. Flow cytometry showed that the number of S phase cells decreased gradually after the treatment, while the proportion of G1 phase and G2 / M phase cells increased significantly. Although the percentage of apoptotic cells in the cells increased over time, the proportion did not exceed 2%. Screened SHG-44 glioma cells in the 125I particles before and after the differential expression and apoptosis-related genes a total of 56 (up 36, down 20). CONCLUSION: 125I particles inhibit the proliferation of glioma cells in a dose-and time-dependent manner through apoptosis, and promote the transformation of cells to apoptosis. 125I particles also have non-apoptotic regulatory cells in cell lines induced by 125I particles (Autophagy); genes related to p53 / ATM pathway, c-myc family, p16, Bcl-2 family in the process of glioma cell apoptosis are involved in inducing apoptosis of glioma cells.