丁酸钠诱导MCF-7细胞凋亡过程中端粒酶活性的变化  

Changes in telomerase activity of MCF-7 cells during apoptosis induced by sodium butyrate

作　　者：奚玲[1] 吴明富[1] 吴剑宏[2] 李辅军[1] 卢运萍[1] 周剑锋[3] 马丁[1] 

机构地区：[1]华中科技大学同济医学院附属同济医院妇产科,武汉430030 [2]华中科技大学同济医学院附属同济医院外科,武汉430030 [3]华中科技大学同济医学院附属同济医院血液科,武汉430030

出　　处：《中华肿瘤杂志》2005年第1期9-12,共4页Chinese Journal of Oncology

基　　金：国家杰出青年基金资助项目 (3 0 0 2 5 0 17) ;国家重点基础研究发展计划资助项目 (2 0 0 2CB5 13 10 0 )

摘　　要：目的　研究丁酸钠诱导MCF 7细胞凋亡过程中端粒酶活性变化及其机制。方法　采用MTT法和倒置相差显微镜观察不同浓度丁酸钠对MCF 7细胞的抑制作用 ,流式细胞仪和琼脂糖凝胶电泳检测 2 .5mmol/L丁酸钠作用后的细胞凋亡情况 ,TRAP ELISA法检测端粒酶活性变化 ,RT PCR分析端粒酶各组分的mRNA表达情况。结果　丁酸钠对MCF 7细胞的抑制作用具有时间和剂量依赖性 ,AnnexinV/PI双染法显示 ,2 .5mmol/L丁酸钠作用 72h后 ,细胞凋亡率为 84 .3% ,琼脂糖凝胶电泳可见间隔为 180bp的DNA梯状条带。 2 .5mmol/L丁酸钠作用 2 4和 4 8h后 ,端粒酶活性分别下降为1.82± 0 .2 2和 1.6 1± 0 .0 9。RT PCR显示 ,端粒酶逆转录酶 (hTERT)表达下降 ,而端粒酶RNA模板(hTR)和端粒酶相关蛋白 (hTP1)表达无明显改变。结论　丁酸钠诱导MCF 7细胞凋亡过程中端粒酶活性下降 ,其机制可能与丁酸钠下调hTERT转录水平有关。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.

关 键 词：丁酸钠 MCF-7细胞 端粒酶活性 凋亡 诱导 表达 抑制作用 转录水平 RT-PCR分析 琼脂糖凝胶电泳 

分 类 号：R737.9[医药卫生—肿瘤]