Taylor Rhys D, Chandran Anandhakumar, Kashiwazaki Gengo, Hashiya Kaori, Bando Toshikazu, Nagase Hiroki, Sugiyama Hiroshi
Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto, 606-8502 (Japan).
Chiba Cancer Center Research Institute, Chuo-Ku, Chiba, 260-8717 (Japan).
Chemistry. 2015 Oct 12;21(42):14996-5003. doi: 10.1002/chem.201501870. Epub 2015 Aug 26.
Mutation of KRAS is a key step in many cancers. Mutations occur most frequently at codon 12, but the targeting of KRAS is notoriously difficult. We recently demonstrated selective reduction in the volume of tumors harboring the KRAS codon 12 mutation in a mouse model by using an alkylating hairpin N-methylpyrrole-N-methylimidazole polyamide seco-1,2,9,9a-tetrahydrocyclopropa[1,2-c]benz[1,2-e]indol-4-one conjugate (conjugate 4) designed to target the KRAS codon 12 mutation sequence. Herein, we have compared the alkylating activity of 4 against three other conjugates that were also designed to target the KRAS codon 12 mutation sequence. Conjugate 4 displayed greater affinity for the G12D mutation sequence than for the G12V sequence. A computer-minimized model suggested that conjugate 4 could bind more efficiently to the G12D match sequence than to a one-base-pair mismatch sequence. Conjugate 4 was modified for next-generation sequencing. Bind-n-Seq analysis supported the evidence showing that conjugate 4 could target the G12D mutation sequence with exceptionally high affinity and the G12V mutation sequence with much higher affinity than that for the wild-type sequence.
KRAS突变是许多癌症中的关键步骤。突变最常发生在密码子12处，但靶向KRAS非常困难。我们最近在小鼠模型中通过使用一种设计用于靶向KRAS密码子12突变序列的烷基化发夹N-甲基吡咯-N-甲基咪唑聚酰胺seco-1,2,9,9a-四氢环丙并[1,2-c]苯并[1,2-e]吲哚-4-酮缀合物（缀合物4），证明了携带KRAS密码子12突变的肿瘤体积有选择性地减小。在此，我们比较了4与其他三种同样设计用于靶向KRAS密码子12突变序列的缀合物的烷基化活性。缀合物4对G12D突变序列的亲和力比对G12V序列的亲和力更高。计算机最小化模型表明，缀合物4与G12D匹配序列的结合效率高于与单碱基对错配序列的结合效率。缀合物4经过修饰用于下一代测序。Bind-n-Seq分析支持了以下证据，即缀合物4可以以极高的亲和力靶向G12D突变序列，并且对G12V突变序列的亲和力比对野生型序列的亲和力高得多。
