人骨形成蛋白-2诱导人脑胶质瘤细胞凋亡的实验研究

The experimental research of the rhBMP-2-induced apoptosis in human glioma cells

目的 探讨重组人骨形成蛋白 2 (rhBMP 2 )对体内、外人脑胶质瘤SHG44细胞生物学特性的影响。方法 绘制rhBMP 2作用前、后的SHG44细胞生长曲线 ,MTT法测定rhBMP 2对SHG44细胞增殖的作用 ;以流式细胞仪、电镜和琼脂糖凝胶电泳分别检测其细胞周期、超微结构和DNA片段改变 ;观察局部注射rhBMP 2对裸鼠皮下SHG44胶质瘤增长的影响。结果 流式细胞检测显示 ,rhBMP 2可抑制SHG44细胞生长 ,具有剂量依赖效应。rhBMP 2作用下的 5mg/L组G1期DNA含量明显增加(5mg/L组 77.4% ,对照组 5 5 .2 % ,P <0 .0 5 ) ,S期含量减少 (5mg/L组 15 .2 % ,对照组 33.3% ,P <0 0 1) ,5mg/L组有凋亡峰存在 (12 .3% ) ;电镜下见该组细胞核染色质浓缩、边集和核碎裂 ,出现凋亡细胞 ;DNA电泳表现为梯状条带 (DNAladder)。局部 4次注射rhBMP 2后 ,SHG44胶质瘤生长减慢 ,体积减小 (肿瘤平均终体积 ,实验组 894mm3 ± 145mm3 ,对照组 5 16 3mm3 ± 10 2 8mm3 ,P <0 .0 1)。结论 rhBMP 2能诱导SHG44人脑胶质瘤细胞凋亡 ,并抑制其增殖。

Objective To investigate the effects of recombinant human bone morphogenetic protein (rhBMP 2)on the biological characteristics of human glioma cells (SHG44) in vivo and in vitro. Methods The growth curve of SHG44 cells was ploted with or without rhBMP 2. The proliferation quantity of SHG44 cells with rhBMP 2 was determined by MTT method. The cell cycle, ultrastructure and DNA fragments of SHG44 cells were detected respectively by flow cytometry(FCM), electron microscope and agarose gel electrophoresis. Tumor growth state of SHG44 gliomas, which grew under the skin of nude mice, was observed with local injection of rhBMP 2. Results FCM showed that rhBMP 2 inhibited the growth of SHG44 cell in vitro and its effect depended on dosage. DNA content of SHG44 cells in G1 phase was obviously increased (5 mg/L group, 77.4%; control group, 55.2%, P <0.05)and the content of its S phase was reduced (5 mg/L group, 15.2%; control group, 33.3%, P <0.01). The apoptosis spike (12.3%) occurred in the 5 mg/L group. The nucleolus chromatin condensation, bound of aggregation and caryorrhexis were observed under the electron microscope and the apoptotic cells appeared. DNA electrophoresis showed a ladder strap (DNA ladder). SHG44 glioma growth was relatively slower and its volume was smaller with the biquadratic local injection of rhBMP 2 (tumor end volume in average: experimental group 894 mm 3±145 mm 3, control group 5 163 mm 3±1 028 mm 3, P <0.01). Conclusion rhBMP 2 can suppress the proliferation of SHG44 gliomas and induce its apoptosis.