西兰花多肽组分 II 诱导神经胶质瘤细胞凋亡的作用及其机制研究

摘要

目的：探讨西兰花多肽组分II诱导胶质瘤细胞凋亡的作用及机制。方法：培养人神经胶质瘤SHG-44细胞，将其分为对照组以及3、10、30和100 mg/L西兰花多肽组分II组，MTT法检测西兰花多肽组分II作用后细胞活力的变化；Annexin V/PI 检测细胞的凋亡率；倒置显微镜观察西兰花多肽组分II诱导细胞凋亡的形态学变化；免疫细胞化学和Western blotting 法检测西兰花多肽组分II作用后Bax、Bcl-2蛋白表达，Western blotting法检测caspase-3蛋白表达。结果：西兰花多肽组分II作用SHG-44细胞24 h、48 h和72 h时均可以降低细胞活力，作用呈时间-剂量依赖性。 Annexin V/PI检测细胞凋亡率发现，各用药组细胞凋亡率随着药物剂量的增加而显著升高。倒置显微镜下观察，西兰花多肽组分II作用SHG-44细胞72 h后，各用药组细胞的密度随药物浓度升高而明显降低，并可见到明显的凋亡小体。细胞免疫组织化学和Western blotting 结果显示，药物作用SHG-44细胞72 h后，与对照组比较，细胞Bax蛋白表达呈上升趋势，Bcl-2蛋白表达呈下降趋势，各用药组Bax/Bcl-2比值均明显增加（P＜0．05或P＜0．01）；Western blotting检测caspase-3蛋白发现，各药物组caspase-3蛋白表达量均增加，与空白对照组比较，30和100 mg/L西兰花多肽组分II组差异有统计学意义（ P＜0．01）。结论：西兰花多肽组分II可提高神经胶质瘤细胞中Bax/Bcl-2蛋白的比值，促进caspase-3蛋白活化，从而诱导肿瘤细胞凋亡。%AIM:To explore the effect of component II of broccoli polypeptide on the apoptosis in glioma cells . METHODS:Human glioma SHG-44 cells were cultured and divided into control group and 3, 10, 30 and 100 mg/L com-ponent II of broccoli polypeptide groups .Cell viability was detected by MTT assay .The apoptotic rates were examined by Annexin V/PI staining.The morphological changes of the cells were observed under inverted microscope .The protein ex-pression of Bax and Bcl-2 was detected by immunocytochemistry and Western blotting .The protein level of caspase-3 was also examined by Western blotting .RESULTS:Treatment with component II of broccoli polypeptide for 24 h, 48 h or 72 h induced significant inhibition of viability of SHG-44 cells in a time-and dose-dependent manner .The results of Annexin V/PI staining showed that the apoptotic rates were increased in treatment groups in a dose -dependent manner .The density of glioma cells was decreased after treated with increasing concentrations of the drug , and the apoptotic bodies were ob-served under inverted microscope at 72 h.The results of immunocytochemistry and Western blotting showed that the expres-sion of Bax protein was increased but Bcl-2 protein expression was decreased , and the ratio of Bax/Bcl-2 was increased sig-nificantly compared with control group (P<0.05 or P<0.01).The level of caspase-3 protein was increased in 30 and 100 mg/L component II of broccoli polypeptide groups compared with control group (P<0.01).CONCLUSION:The compo-nent II of broccoli polypeptide increases the ratio of Bax /Bcl-2 and activates caspase-3 protein, thus inducing the apoptosis of glioma cells.