近日,，國際著名雜志《美國國家科學(xué)院院刊》PNAS刊登了瑞士蘇黎士大學(xué)的研究人員的最新研究成果，科學(xué)家們研發(fā)了一種新物質(zhì),，可用來標(biāo)記和觀察動物體內(nèi)的DNA合成過程,。該技術(shù)的應(yīng)用為藥物研發(fā)提供了新策略。
詳細(xì)了解動物體內(nèi)DNA和蛋白質(zhì)等大分子合成是理解生物系統(tǒng)和設(shè)計疾病治療策略的必要條件,。通常,，通過人工合成小分子標(biāo)記物摻入生物體自身合成過程來達(dá)到可視化DNA合成的目的。但是,，直到現(xiàn)在該方法有一個重大的局限性：標(biāo)記物具有毒性并導(dǎo)致細(xì)胞死亡,。內(nèi)森·利德基（Nathan Luedtke）領(lǐng)導(dǎo)的小組研發(fā)了一種叫“F-ara-Edu”的核苷。用它來替換胸腺嘧啶脫氧核苷,，標(biāo)記DNA對生物體基因組功能幾乎沒有影響,，毒性也大為降低，檢測也更靈敏,。
利德基表示,，通過可視化新DNA的合成，就能夠鑒定病毒感染和腫瘤增長的位點,。這將引領(lǐng)藥物研發(fā)新策略,。（生物谷Bioon.com）
doi:10.1073/pnas.1101126108
PMC:
PMID:
Dynamic metabolic labeling of DNA in vivo with arabinosyl nucleosides
Neef, Anne B.; Luedtke, Nathan W.
Commonly used metabolic labels for DNA, including 5-ethynyl-2′-deoxyuridine (EdU) and BrdU, are toxic antimetabolites that cause DNA instability, necrosis, and cell-cycle arrest. In addition to perturbing biological function, these properties can prevent metabolic labeling studies where subsequent tissue survival is needed. To bypass the metabolic pathways responsible for toxicity, while maintaining the ability to be metabolically incorporated into DNA, we synthesized and evaluated a small family of arabinofuranosyl-ethynyluracil derivatives. Among these, (2′S)-2′-deoxy-2′-fluoro-5-ethynyluridine (F-ara-EdU) exhibited selective DNA labeling, yet had a minimal impact on genome function in diverse tissue types. Metabolic incorporation of F-ara-EdU into DNA was readily detectable using copper(I)-catalyzed azide–alkyne “click” reactions with fluorescent azides. F-ara-EdU is less toxic than both BrdU and EdU, and it can be detected with greater sensitivity in experiments where long-term cell survival and/or deep-tissue imaging are desired. In contrast to previously reported 2′-arabino modified nucleosides and EdU, F-ara-EdU causes little or no cellular arrest or DNA synthesis inhibition. F-ara-EdU is therefore ideally suited for pulse-chase experiments aimed at “birth dating” DNA in vivo. As a demonstration, Zebrafish embryos were microinjected with F-ara-EdU at the one-cell stage and chased by BrdU at 10 h after fertilization. Following 3 d of development, complex patterns of quiescent/senescent cells containing only F-ara-EdU were observed in larvae along the dorsal side of the notochord and epithelia. Arabinosyl nucleoside derivatives therefore provide unique and effective means to introduce bioorthogonal functional groups into DNA for diverse applications in basic research, biotechnology, and drug discovery.
