Weidner D A, Busch H
Department of Pharmacology, Baylor College of Medicine, Houston, TX 77030.
Oncol Res. 1994;6(6):237-42.
To determine the sequence specificity with which various antisense phosphorothioate oligonucleotides to the p120 gene could direct RNAse H-dependent cleavage of p120 mRNA, an in vitro RNAse H assay was done on in vitro synthesized p120 mRNA. Three oligonucleotides tested (ISIS 3462, coding region; ISIS 3466, 3' untranslated region; and ISIS 3782, 3' untranslated region) directed cleavage of p120 mRNA at the target sites. In addition, several additional cleavage products from nontarget sites were detected. A computer sequence homology search revealed that these additional bands probably result from cleavage at regions of complementarity of eight or nine contiguous bases of the oligonucleotide and the p120 mRNA. These findings suggest that such nontarget specific cleavages may account for multiple effects of phosphorothioate oligonucleotides.
为了确定针对p120基因的各种反义硫代磷酸酯寡核苷酸指导RNA酶H依赖性切割p120 mRNA的序列特异性，对体外合成的p120 mRNA进行了体外RNA酶H测定。测试的三种寡核苷酸（ISIS 3462，编码区；ISIS 3466，3'非翻译区；以及ISIS 3782，3'非翻译区）在靶位点指导了p120 mRNA的切割。此外，还检测到了来自非靶位点的几种额外切割产物。计算机序列同源性搜索显示，这些额外的条带可能是由于寡核苷酸和p120 mRNA的八个或九个连续碱基的互补区域发生切割所致。这些发现表明，这种非靶标特异性切割可能是硫代磷酸酯寡核苷酸多种效应的原因。
