阿霉素对端粒序列及其相似物电泳迁移速度的影响

Effects of adriamycin on telomere sequence and its analogue electrophoresis migration velocity

目的观察阿霉素对端粒序列d(TTAGGG)不同重复次数以及与其具有相似结构的单核苷酸序列二级结构的影响,探讨阿霉素诱导端粒复重序列d(TTAGGG)n形成鸟嘌呤四联体的机制。方法人工化学合成线性单核苷酸序列d(TTAGGG)、d(TTAGGG)2、d(TTAGGG)3、d(TTAGGG)4、d(TTAGGG)5、d(TTGGAG)4、d(TG-TAGG)4、d(TAGGTG)4、d(TTGAGG)4;用非变性聚丙烯酰胺凝胶电泳法观察不同浓度阿霉素(0、1.25、2.5、5.0μg/mL)对端粒重复序列d(TTAGGG)4电泳迁移速度的影响;观察5.0μg/mL阿霉素对d(TTAGGG)、d(TTAGGG)2、d(TTAGGG)3、d(TTAGGG)4、d(TTAGGG)5电泳迁移速度的影响;观察5.0μg/mL阿霉素对d(TTAGGG)4、d(TTGGAG)4、d(TGTAGG)4、d(TAGGTG)4、d(TTGAGG)4电泳迁移速度的影响。结果随着阿霉素的浓度的提高,端粒重复序列d(TTAGGG)4电泳迁移速度也随之加快;阿霉素可使端粒重复序列d(TTAGGG)4、d(TTAGGG)5序列的二级结构发生改变,从而加快其电泳迁移的速度,对d(TTAGGG)、d(TTAGGG)2、d(TTAGGG)3的电泳迁移速度没有影响;阿霉素可对含有GGG碱基排列的端粒重复序列发生电泳迁移速度的加快,而对无GGG碱基排列的端粒序列类似物的电泳迁移没有影响。结论在阿霉素存在条件下,端粒序列d(TTAGGG)n重复4次以上的寡核苷酸序列的电泳迁移速度加快,其二级结构的改变是迁移速度加快的主要原因,这种改变后形成的二级结构可能为G-四联体。

Objective To detect the mechanism of G-quadruplex production by observing the effects of adriamycin on telomere sequence d（TYAGGG） in different repeated times and the secondary structure of telomere＇ s analogue single nucleotide sequence. Methods The oligonucleotide sequences d （ TrAGGG）, d （TYAGGG） 2, d （ TrAGGG ） 3, d （TTAGGG）,, d（TTAGGG） s, d（TYGGAG） 4, d（TGTAGG） 4, d（TAGGTG） 4, d（TTGAGG） 4 were artificially synthetized by chemical method; telomere repeat sequence of d （TTAGGG） 4 were effected by different concentrations of adriamycin （0, 1.25,2.5,5μg/mL） whose effects on electrophoresis migration velocity were observed by the non-denaturing polyacrylamide gel electrophoresis method. The effects of adriamycin at the concentrations of 5μg/ml on the electrophoresis migration velocity of d（TYAGGG）, d（TTAGGG） 2, d（TYAGGG） 3, d（rITAGGG） 4 and d（TTAGGG） s were observed by performing non-denaturing polyacrylamide gel electrophoresis ; meanwhile, the effects of adriamycin at the concentrations of 5 μg/ml on the electrophoresis migration velocity of d （TTAGGG） 4, d （TYGGAG） 4, d （TGTAGG） 4, d （TAGGTG） 4 and d （ TTGAGG）4 were also observed by performing non-denaturing polyacrylamide gel electrophoresis. Results With the increasing concentrations of adriamycin, the electrophoretic migration velocity of telomere sequence d （TTAGGG）4 was accelerating and the spatial structure was changing increasingly; adriamycin at concentration of 5μg./ml could make the internal structure of telomere repeat sequence d（TTAGGG）4 and d（TTAGGG）5 change, so as to speed up the electrophoresis migration velocity; whereas adriamycin had no influence on d（ TTAGGG）, d（rrTAGGG）2 and d（TYAGGG） ; adriamycin at concentration of 5 μg/mL could accelerate electrophoresis velocity on sequence containing telomere repeat GGG base, but had no effect on sequence without GGG base. Conclusion With the effect of adriamycin, the electrophoresis velocity of oligonucleotide sequences repeated more than four times has accelerated, and the secondary structure changing is the main reason for the difference. The secondary structure formed after changing might be the G-quadruplex.