摘要
为了研究三氧化二砷(As2O3)诱导人类骨髓增生异常综合征难治性贫血伴原始细胞过多型(MDS-RAEB)细胞株MUTZ-1细胞凋亡的端粒酶调控机制,采用端粒重复序列扩增-酶联免疫吸附试验(TRAP-ELISA)检测端粒酶活性;RT-PCR法检测端粒酶逆转录酶(hTERT)、TRF1(TTAGGGrepeatbindingfactor1)、TRF2(TTAGGGrepeatbindingfactor2)、bcl-2、bax等基因mRNA水平的表达;磷脂酰丝氨酸(PS)转位等方法检测细胞凋亡。结果表明:1-8μmol/LAs2O3诱导MUTZ-1细胞凋亡呈时间、浓度依赖关系。在该浓度范围内,As2O3可下调细胞端粒酶活性,且端粒酶活性下调与凋亡细胞阳性率呈明显负相关(r=-0.938,P=0.018)。MUTZ-1细胞经As2O3作用后,hTERT基因mRNA表达下调,并与端粒酶活性变化呈正相关(r=0.783,P=0.022),但As2O3对TRF1及TRF2基因mRNA表达没有明显影响。MUTZ-1细胞端粒酶活性受抑制同时,伴有bcl-2mRNA表达下调及bcl-2/bax比值下降。结论:As2O3可能通过抑制细胞端粒酶活性及hTERT表达,诱导MUTZ-1细胞凋亡。As2O3抑制MUTZ-1细胞端粒酶活性可能是诱导该凋亡机制之一。
To investigate the mechanisms of the telomerase regulations during the apoptosis of the human MDS-RAEB cell line MUTZ-1 cells induced by arsenic trioxide （ As2O3 ）, telomerase activity was detected by TRAP-ELISA and the expressions of mRNAs of hTERT, TRF1 （ TTAGGG repeat binding factor 1 ）, TRF2 （ TTAGGG repeat binding factor 2）, bcl-2, and bax genes were detected by RT-PCR. Apoptosis was detected by translocation of phosphatidylserine （PS） by flow cytometry. The results showed that 1 -8μmol/L of As2O3 induced typical apoptosis of MUIZ-1 cells in the dose-and time-dependent manners, the telomerase activity could be down-regulated at this concentration and negatively correlated with increased apoptosis （r = -0. 938, P = 0.018 ）. The expression of telomerase activity was positively related to the expression of hTERT （ r = 0.783,P=0. 022 ）, but As2O3 had no effect on the mRNA expression of TRF1 and TRF2 genes. The inhibition of telomerase activity by As2O3 on MUTZ-1 cells was accompanied with the low expression of bcl-2 gene and the decrease of bcl-2/bax ratio. It is concluded that the apoptosis of MUTZ-1 cells induced by As2O3 may occur via the inhibition of telomerase activity and down-regulation of the expression of hTERT mRNA,and this may be one of the mechanisms inducing apoptosis in MUTZ-1 cells treated by As2O3.
出处
《中国实验血液学杂志》
CAS
CSCD
2005年第4期615-619,共5页
Journal of Experimental Hematology
基金
浙江省科学技术厅基金资助项目
编号2003C23013
