Trantakis Ioannis A, Nilforoushan Arman, Dahlmann Heidi A, Stäuble Celine K, Sturla Shana J
Department of Health Sciences and Technology, ETH Zürich , Schmelzbergstrasse 9, 8092 Zurich, Switzerland.
J Am Chem Soc. 2016 Jul 13;138(27):8497-504. doi: 10.1021/jacs.6b03599. Epub 2016 Jul 1.
Exposure of DNA to chemicals can result in the formation of DNA adducts, a molecular initiating event in genotoxin-induced carcinogenesis. O(6)-Methylguanine (O(6)-MeG) is a highly mutagenic DNA adduct that forms in human genomic DNA upon reaction with methylating agents of dietary, environmental, or endogenous origin. In this work, we report the design and synthesis of novel non-natural nucleoside analogues 1'-β-[1-naphtho[2,3-d]imidazol-2(3H)-one)]-2'-deoxy-d-ribofuranose and 1'-β-[1-naphtho[2,3-d]imidazole]-2'-deoxy-d-ribofuranose and their use for quantifying O(6)-MeG within mutational hotspots of the human KRAS gene. The novel nucleoside analogues were incorporated into oligonucleotides conjugated to gold nanoparticles to comprise a DNA hybridization probe system for detecting O(6)-MeG in a sequence-specific manner on the basis of colorimetric readout of the nanoparticles. The concept described herein is unique in utilizing new nucleoside analogues with elongated hydrophobic surfaces to successfully measure in-gene abundance of O(6)-MeG in mixtures with competing unmodified DNA.
DNA暴露于化学物质中会导致DNA加合物的形成，这是基因毒素诱导致癌过程中的一个分子起始事件。O(6)-甲基鸟嘌呤（O(6)-MeG）是一种高度诱变的DNA加合物，在人类基因组DNA与饮食、环境或内源性来源的甲基化剂反应时形成。在这项工作中，我们报告了新型非天然核苷类似物1'-β-[1-萘并[2,3-d]咪唑-2(3H)-酮]-2'-脱氧-D-核糖呋喃糖和1'-β-[1-萘并[2,3-d]咪唑]-2'-脱氧-D-核糖呋喃糖的设计与合成，以及它们用于定量人类KRAS基因突变热点内O(6)-MeG的用途。将新型核苷类似物掺入与金纳米颗粒缀合的寡核苷酸中，以构成一个DNA杂交探针系统，用于基于纳米颗粒的比色读数以序列特异性方式检测O(6)-MeG。本文所述概念独特之处在于利用具有延长疏水表面的新核苷类似物，成功地在与竞争性未修饰DNA的混合物中测量基因内O(6)-MeG的丰度。
