顺铂在TRAIL/APO-2L致胶质瘤细胞凋亡作用中影响机制的研究

The effects of CDDP on the progress of apoptosis in glioma cell induced by TRAIL/APO-2L

目的探讨TRAIL对胶质瘤细胞凋亡的影响,并进一步研究DNA破坏药物顺铂(CDDP)在与其联合作用诱导细胞凋亡中影响作用的机制。方法行人脑胶质瘤U251细胞株的培养,应用不同浓度TRAIL和CDDP作用于胶质瘤U251细胞,MTT法检测TRAIL和CDDP分别及联合作用于U251细胞后的存活率,并以亚毒剂量的TRAIL和CDDP联合作用后,流式细胞仪检测其凋亡率。Westernblot方法检测CDDP作用前后TRAIL受体DR5表达量的变化。结果MTT结果:在一定时间范围内,随着药物浓度增加,TRAIL和CDDP分别及联合作用皆使胶质瘤U251细胞存活率逐渐降低,其中两者的联合作用效果明显,与分别作用组差异有统计学意义(P<0.01)。亚毒剂量的TRAIL(50ng·ml-1)、CDDP(4μg·ml-1)分别及联合作用人脑胶质瘤U251细胞24h后,存活率分别为:72.43%,75.56%,23.45%。亚毒剂量的TRAIL(50ng·ml-1)、CDDP(4μg·ml-1)单独或联合作用组致胶质瘤细胞凋亡率分别为25.61%、20.59%、62.33%。单独应用组与联合组之间差异有统计学意义(P<0.01)。Westernblot法检测显示:CDDP作用后较作用前DR5表达有明显增高,随CDDP剂量增多,DR5表达量逐渐增加。结论TRAIL和CDDP联合作用能显著增强其对人U251胶质瘤细胞凋亡的诱导,其机制可能与CDDP能上调TRAIL死亡受体DR5的表达有关。

Objective To investigate the effects of TRAIL on apoptosis in human glioma cell line and study the mechanism of CDDP on apoptotic process induced by TRAIL . Methods Different doses of CDDP was added in the media of glioma cells with treatment of different doses of TRAIL, then viability was examined by MTT assay. Afterwards, sub-poisonous dose of TRAIL and CDDP were added into media of glioma cells, the apoptotic percentages of three experimental groups that included the TRAIL, CDDP and TRAIL-CDDP groups were examined by FCM. Western blot assay was used to examine the expression of DR5 with or without CDDP. Results Within a certain time, when the doses of TRAIL and CDDP increased, the viability of U251 glioma cell became lower synchronously. The viability of glioma cells induced by TRAIL, CDDP and TRAIL-CDDP which were 50 ng·ml -1 and 4μg·ml -1and 50 ng·ml -1- 4μg·ml -1 were 72.43% , 75.56% and 23.45%,respectively. The apoptotic percentages of glioma cells induced by TRAIL, CDDP and TRAIL-CDDP were 25.61%,20.59% and 62.33%, respectively. The apoptotic percentages of glioma cells induced by CDDP and TRAIL were significantly lower than that by TRAIL-CDDP(P<0.01). Western blot showed that the expression of DR5 of cells with CDDP was higher than that without CDDP. The expression of DR5 was increased gradually within certain time. Conclusions The apoptosis of glioma cell induced by TRAIL-CDDP was significantly higher than that of cells treated by TRAIL or CDDP solely. The mechanism may be that the expression of DR5 was up-regulated by CDDP.