Yamakawa H, Abe T, Saito T, Takai K, Yamamoto N, Takaku H
Department of Industrial Chemistry, Chiba Institute of Technology, Narashino, Japan.
Bioorg Med Chem. 1998 Jul;6(7):1025-32. doi: 10.1016/s0968-0896(98)00060-1.
We have designed a new class of oligonucleotides, 'dumbbell RNA/DNA chimeric phosphodiester oligonucleotides', consisting of a sense RNA sequence and its complementary antisense DNA sequence, with two hairpin loop structures. The reaction of the Nicked (NDRDON) and Circular (CDRNON) dumbbell DNA/RNA chimeric oligonucleotides with RNase H gave the corresponding antisense phosphodiester oligodeoxynucleotide together with the sense RNA cleavage products. The liberated antisense phosphodiester oligodeoxynucleotide was bound to the target 45 mer RNA, which gave 45 mer RNA cleavage products by treatment with RNase H. The circular dumbbell RNA/DNA chimeric oligonucleotide showed more nuclease resistance than the linear antisense phosphodiester oligodeoxynucleotide (anti-ODN) and the nicked dumbbell RNA/DNA chimeric oligodeoxynucleotide. The circularization, achieved by joining the 3' and the 5' ends of RNA/DNA chimeric oligonucleotides containing two hairpin loop structures, increases the oligonucleotide uptake into cells, as compared with the nicked dumbbell RNA/DNA chimeric oligonucleotide and the linear antisense phosphodiester oligodeoxynucleotides. When the circular dumbbell RNA/DNA chimeric oligonucleotide is directly delivered into retrovirus infected cells, its antisense phosphodiester oligodeoxynucleotide function appears.
我们设计了一类新型寡核苷酸，即“哑铃状RNA/DNA嵌合磷酸二酯寡核苷酸”，它由一条有义RNA序列及其互补反义DNA序列组成，并带有两个发夹环结构。带切口的（NDRDON）和环状的（CDRNON）哑铃状DNA/RNA嵌合寡核苷酸与RNase H反应，生成了相应的反义磷酸二酯寡脱氧核苷酸以及有义RNA的切割产物。释放出的反义磷酸二酯寡脱氧核苷酸与目标45聚体RNA结合，经RNase H处理后产生45聚体RNA切割产物。环状哑铃状RNA/DNA嵌合寡核苷酸比线性反义磷酸二酯寡脱氧核苷酸（反义ODN）和带切口的哑铃状RNA/DNA嵌合寡脱氧核苷酸表现出更强的核酸酶抗性。通过连接含有两个发夹环结构的RNA/DNA嵌合寡核苷酸的3'端和5'端实现的环化，与带切口的哑铃状RNA/DNA嵌合寡核苷酸和线性反义磷酸二酯寡脱氧核苷酸相比，增加了寡核苷酸对细胞的摄取。当环状哑铃状RNA/DNA嵌合寡核苷酸直接导入逆转录病毒感染的细胞时，其反义磷酸二酯寡脱氧核苷酸的功能得以显现。
