榄香烯诱导人脑胶质瘤U251细胞凋亡及对端粒酶活性和hTERT表达影响的研究  

The Studies on the Apoptosis of Human Glioma U251 cell line and the Effect of Telomerase Activity and Expression of hTERT By Elemene

作　　者：陈春美[1] 杨卫忠[1] 王春华[1] 石松生[1] 易海波[1] 黄勇[1] 王锐[1] 杨贤义[1] 

机构地区：[1]福建医科大学附属协和医院神经外科福建省神经外科研究所,福建省350001

出　　处：《中国肿瘤临床》2006年第5期280-283,共4页Chinese Journal of Clinical Oncology

基　　金：福建省科技厅科研基金项目资助(编号:20012031)

摘　　要：目的:探讨榄香烯诱导人脑胶质瘤U251细胞凋亡及其影响端粒酶活性及其催化亚单位人端粒酶逆转录酶(hTERT)表达的机制。方法:将榄香烯处理人脑胶质瘤U251细胞株后,用MTT法检测细胞增殖抑制率,并求出半数抑制浓度(IC50),倒置显微镜和电镜观察经榄香烯处理的U251细胞形态,流式细胞仪和原位末端标记技术检测细胞周期及细胞凋亡率的变化,免疫荧光技术观察凋亡小体,流式细胞仪测定bcl-2表达水平,端粒重复扩增(TRAP)法测定端粒酶活性的变化,RT-PCR检测bcl-2和hTERT的表达。结果:榄香烯对U251细胞株增殖具有抑制作用,呈剂量和作用时间的依赖性,IC50为0.062mg/ml,倒置显微镜下可见榄香烯组细胞皱缩、变小,电镜下可见具有典型新月形核的凋亡细胞和凋亡小体,流式细胞仪检测榄香烯阻滞U251细胞周期中S期向G2/M期的转变过程,减少有丝分裂,并引起细胞凋亡,免疫荧光技术观察凋亡小体,TRAP法发现榄香烯可以降低端粒酶活性的变化,呈时间和剂量依赖型。RT-PCR分别证实榄香烯降低bcl-2和hTERT基因表达水平。结论:榄香烯诱导人脑胶质瘤U251细胞凋亡,并抑制U251细胞端粒酶的活性,榄香烯作用于胶质瘤的分子生物学机制可能通过抑制bcl-2表达,下调hTERT基因,降低端粒酶的活性,从而诱导细胞调亡。Objective： To investigate the mechanism of cellular apoptosis of human glioma U251 cell line and the effect of telomerase activity and expression of human telomerase reverse transcripase （ hTERT） by elemene. Methods： Human glioma U251 cells were treated with elemene, the inhibitory effect was then examined using MTT and the IC50 was worked out. The morphological alterations was observed by inverted microscope and electron microscope and the apoptosis was evaluated by flow cytometry analysis and light microscopy. The telomerase activity was determined by telomeric repeat assay protocol （TRAP） and the expression of bcl-2 and hTERT gene were examined by RT-PCR. Results： Our studies showed that elemene had a markedly antineoplastic activity on glioma U251 cell line with the way of dose- and time-dependence and IC50 was 0.062mg/ml. After administration of elemene the cellular morphology became smaller under inverted microscope and the apoptotic cells and bodies were found under electron microscope, The flow cytometry analysis showed that elemene inhibited the cell cycle transference from phase S to phase G2/M and induced apoptosis. The apoptosis in glioma cells was observed by light microscope, Elemene decreased telomerase activity, in a time- and close-dependent manner. Elemene decreased the expression of bcl-2 and hTERT gene by RT-PCR examination. Con-clusions： Elemene induced apoptosis of human glioma U251 cell line, inhibited the telomerase activity, the molecular mechanisms of elemene effect on U251 cell may be related to down-regulation of hTERT gene expression and then decrease telomerase activity through the inhibition of bcl-2 gene.

关 键 词：榄香烯 胶质瘤 细胞凋亡 bcl-2 端粒酶 HTERT 

分 类 号：R739.41[医药卫生—肿瘤]