转录因子Sp1和Sp3对JurkatT细胞端粒酶活性的调节作用

Regulation of telomerase activity in Jurkat Tcells by transcription factors Sp1and Sp3

目的探讨转录因子Sp1、p3对JurkatT细胞端粒酶活性和端粒酶逆转录酶(hTERT)的调节作用。方法用脂质体将Sp1、Sp3表达载体转入JurkatT细胞,用Westernblotting方法检测蛋白表达水平;用端粒酶PCR-ELISA法检测细胞端粒酶活性并用银染显示端粒酶活性梯度;用RT-PCR方法检测hTERTmRNA水平。结果Sp1、Sp3载体转化36h的细胞Sp1、Sp3蛋白水平分别升高59.6%(P<0.01)和36.8%(P<0.05);随着Sp1表达水平的增加,端粒酶活性和hTERTmRNA水平明显增加,增加率分别为38.5%(P<0.05)和25.4%(P<0.05)。而Sp3表达载体对端粒酶活性和hTERTmRNA水平无明显影响。结论转录因子Sp1通过调节hTERTmRNA转录水平而调节JurkatT细胞端粒酶活性,Sp3无此作用。

Objective To investigate the role of transcription factors Sp1and Sp3in the regulation of telomerase activity and human telomerase reverse transcriptase(hTERT)in Jurkat T cells.Methods By way of lipofectamine,Sp1and Sp3expression vectors were transferred into Jurkat T cells in which the protein expression levels of Sp1and Sp3were examined by Western blotting.Telomerase PCR-ELISA was used to assess the telomerase activity,and telomerase-mediated DNA-ladders were analyzed by silver staining and hTERT mRNA level determined by reverse transcriptase-PCR(RT-PCR).Results Treatment of Jurkat T cells with Sp1expression vector for36h resulted in significant increase in Sp1and Sp3protein levels by59.6%(P<0.01)and36.8%(P<0.05)respectively.Enhancement of Sp1expression obviously increased telomerase activity and hTERT mRNA levels at a rate of38.5%(P<0.05)and25.4%(P<0.05)respectively,whereas Sp3evinced no significant effect on both telomerase activity and hTERT mRNA levels.Conclusion Transcription factor Sp1,but not Sp3,regulates telomerase activity by altering hTERT mRNA levels in Jurkat T cells.