抗肿瘤多药抗性核酶转录质粒的构建及其体外切割研究

The construction of a plasmid transcribing anti-mdr1 ribozyme and its cleaving reaction in vitro

目的 探讨体外核酶对肿瘤多药抗性相关基因mdr1靶RNA分子的切割作用及其影响因素。方法 利用计算机软件设计能特异切割mdr1 mRNA的锤头状核酶（ribozyme），并构建抗mdr1-ribozyme和靶分子的体外转录质粒，进行体外切割实验。结果 发现抗mdr1-ribozyme能较好地切割mdr1 mRNA。 结论 抗肿瘤多药抗性核酶的体外研究为其体内应用提供了参考，ribozyme有可能成为逆转肿瘤多药抗性的新药物。

Objective To study the in vitro cleavage of mdr1 target RNA by ribozyme and its influencing factors. Methods By using the computer software we designed a specific hammerhead ribozyme possessing catalytic activity that cleaves the mdr1 mRNA. A RNA-trimming plasmid pRG5mR3 and a target RNA trascribing plasmid pSABl were constructed, and a specific ribozyme cleaving reaction to target RNA was analysed. Results It was found that anti-mdr1-ribozyme is able to cleave a transcribed mdr1 mRNA fragment under physiological conditions. Conclusion The ribozyme may be targeted to inhibit the expression of the mdr1 gene in vivo, and may potentially offer a help in the strategy of cancer treatment.