[丁酸钠诱导MCF-7细胞凋亡过程中端粒酶活性的变化降低]

[Changes in telomerase activity decreases in MCF-7 cells during apoptosis induced by sodium butyrate].

作者信息

Xi Ling, Wu Ming-Fu, Wu Jian-Hong, Li Fu-Jun, Lu Yun-Ping, Zhou Jian-Feng, Ma Ding

机构信息

Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.

出版信息

Zhonghua Zhong Liu Za Zhi. 2005 Jan;27(1):9-12.

PMID:15771789

Abstract

OBJECTIVE

To investigate telomerase activity of MCF-7 mammary cancer cells during apoptosis induced by sodium butyrate (SB) in vitro and its mechanism.

METHODS

The proliferative activity of MCF-7 cells was assessed by morphology and MTT assay. Cell apoptosis was confirmed by DNA fragmentation and phosphatidylserine (PS) externalization. Telomerase activity was examined by TRAP-ELISA. The expression status of telomerase subunits was analyzed by RT-PCR.

RESULTS

A time- and dose-dependent inhibition was detected in MCF-7 cells treated with SB. At 72 hr after SB (2.5 mmol/L) treatment, MCF-7 cells were apoptotic with a rate of 84.3% by flow cytometric assay (AnnexinV/PI double staining). Apoptosis was also confirmed by DNA fragmentation. Telomerase activity and expression level of hTERT, the key subunit of telomerase, decreased at 24-hour time point after SB treatment. No significant changes were observed in the expression of hTR and hTP, the other two subunits of telomerase.

CONCLUSION

Telomerase activity decreases in MCF-7 cells during apoptosis induced by sodium butyrate. The underlying mechanism might be related to the down regulation of hTERT transcription.

摘要

目的

研究丁酸钠（SB）体外诱导MCF-7乳腺癌细胞凋亡过程中端粒酶活性及其机制。

方法

通过形态学和MTT法评估MCF-7细胞的增殖活性。通过DNA片段化和磷脂酰丝氨酸（PS）外化确认细胞凋亡。采用端粒重复序列扩增-酶联免疫吸附测定（TRAP-ELISA）检测端粒酶活性。通过逆转录-聚合酶链反应（RT-PCR）分析端粒酶亚基的表达状态。

结果

用SB处理的MCF-7细胞呈现时间和剂量依赖性抑制。SB（2.5 mmol/L）处理72小时后，流式细胞术检测（AnnexinV/PI双染法）显示MCF-7细胞凋亡率为84.3%。DNA片段化也证实了细胞凋亡。SB处理24小时后，端粒酶活性以及端粒酶关键亚基hTERT的表达水平降低。端粒酶的另外两个亚基hTR和hTP的表达未观察到显著变化。