反义药物作用中的“靶二级结构域”

“TARGET SECONDARY STRUCTURAL MOTIF” IN THE ACTION OF ANTISENSE OLIGODEOXYNUCLEOTIDES

目的 在计算机模拟mRNA二级结构与定量构效关系分析的基础上优化反义药物设计。方法 使用软件RNAstructure模拟mRNA二级结构 ,针对二级结构单元进行反义药物设计 ,用肺腺癌细胞株A5 49评价反义药物的体外抗肿瘤生物活性 ,用软件SPSS进行多元回归分析。结果 有效药物作用靶点相对集中地分布于由若干二级结构单元组成的局部二级结构区域。我们称之为“靶二级结构域 (靶域 )”。“靶域”结构相对稳定 ,但其中包含不稳定二级结构单元 (ΔG° >0 )。针对不同“靶域”设计的反义药物显示不同的生物活性 (P <0 0 1) ,但靶向同一“靶域”的反义药物生物活性无统计差别。结论 “靶域”现象有助于反义药物靶点的选择 ,并对探针。

AIM To optimize the antisense drug design based on the methods of secondary structure prediction of target mRNA by computer and the quantitative structure activity relationship analysis. METHODS The secondary structures of mRNA were predicted by the software RNAstructure, then the antisense phosphorothioate oligodeoxynucleotides (AS ODN) were designed against the secondary structural elements. The in vitro anti tumor bioactivity of AS ODN was evaluated by A549 lung carcinoma cell line. The multiple regression was performed with the computer program SPSS. RESULTS AS ODN with high bioactivity concentrated on some local secondary structural motifs that were composed of several secondary structural elements, designated here as “target secondary structural motif” (target motif). The target motifs were relatively stable in the whole mRNA structures, but there were one or more unstable secondary structural elements (free energy>0) such as internal loops, knots, and hairpins, especially the bulge loops in the motif. Bioactivities of AS ODN targeting different “target motifs” were statistically different ( P <0 01) while AS ODN against the same “target motif” were with similar effects. CONCLUSION The concept of the “target motif” was helpful for optimizing the antisense drug design and might be useful for discovering the local function of mRNA and designing oligonucleotide probes and primers.