抑制端粒酶催化亚基的表达促进Survivin蛋白的降解  

Inhibiting Expression of Human Telomerase Reverse Transcriptase Promotes Degradation of Survivin Protein

作　　者：梅柱中[1] 郑晓飞[1] 董燕[1] 宋宜[1] 刘斌[1] 孙国敬[1] 孙志贤[1] 

机构地区：[1]军事医学科学院放射医学研究所生物化学与分子生物学实验室,北京100850

出　　处：《癌症》2005年第5期525-530,共6页Chinese Journal of Cancer

基　　金：国家自然科学基金资助项目(No.30300416)~~

摘　　要：背景与目的:研究表明,在肿瘤细胞中端粒酶催化亚基(hum antelom erase reverse transcriptase,hTERT)与存活素(Survivin)的表达具有相关性,本研究拟探索肿瘤细胞中hTERT与Survivin在功能上是否存在相互调控作用。方法:采用反义核酸分别抑制survivin与hTERT在H eLa S3细胞中的表达,端粒重复扩增法检测细胞中端粒酶活性的变化,并分别采用W estern印迹与RT-PCR分析细胞中Survivin蛋白水平与m RNA水平的变化,M TT法检测H eLa S3细胞的增殖变化。结果:采用反义核酸抑制H eLa S3细胞中survivin的表达对端粒酶的活性没有影响,但是采用反义核酸No.14抑制hTERT的表达可以显著降低细胞中Survivin蛋白水平,而m RNA水平未受影响。而且当反义核酸No.14的浓度在200～1000nm ol/L范围内时,Survivin蛋白水平的下降与反义寡核苷酸的浓度呈正相关,这种下降可以被泛素化蛋白酶抑制剂lactacystin和M G132所抑制。此外,在H eLa S3细胞中同时抑制hTERT与survivin的表达可以协同性地抑制细胞增殖。结论:抑制H eLa S3细胞中hTERT的表达可以促使Survivin蛋白通过泛素蛋白酶体途径降解。BACKGROUND & OBJECTIVE: The expression of Survivin in cancer cells highly correlates with that of human telomerase reverse transcriptase (hTERT). Both of them are ideal targets for cancer gene therapy. This study aimed to clarify if they regulate each other in cancer cells. METHODS: The expressions of Survivin and hTERT in HeLa S3 cells were inhibited by antisense oligonucleotide respectively. Activity of telomerase was detected by telomerase repeat amplification (TRAP) assay. Protein and mRNA levels of Survivin were analyzed by Western blot and reverse transcription-polymerase chain reaction (RT-PCR) respectively. Proliferation of HeLa S3 cells was analyzed by MTT assay. RESULTS: Inhibiting the expression of Survivin in HeLa S3 cells had no effects on telomerase activity. Inhibiting the expression of hTERT by antisense oligonucleotide No.14 decreased protein level of Survivin, which was negatively correlated with the concentration of No.14 (200-1 000 nmol/L), but didn't change mRNA level of survivin. The decrease of Survivin level was inhibited by proteasome inhibitor lactacystin and MG132. Furthermore, simultaneous inhibition of hTERT and survivin co-efficiently inhibited proliferation of HeLa S3 cells. CONCLUSION: Inhibiting the expression of hTERT in HeLa S3 cells promotes ubiquitin-proteasome degradation of Survivin.

关 键 词：端粒酶 存活素 泛素蛋白酶体降解途径 反义寡核苷酸 

分 类 号：R73-36[医药卫生—肿瘤]