Metabolism-Based Click-Mediated Platform for Specific Imaging and Quantification of Cell Surface Sialic Acids

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• 作者：Yong Liang ; Xin Jiang ; Rong Yuan ; Yang Zhou ; Caixia Ji ; Limin Yang ; Haifeng Chen ; Qiuquan Wang
• 刊名：Analytical Chemistry
• 出版年：2017
• 出版时间：January 3, 2017
• 年：2017
• 卷：89
• 期：1
• 页码：538-543
• 全文大小：523K
• ISSN：1520-6882

文摘

Although we believe that the cell surface sialic acids (Sias) are playing an important role in cell–cell interactions and related tumor metastasis processes, acquisition of their quantitative information has yet been a challenge to date. Here, we reported the construction of a new analytical platform for Sias-specific imaging and quantification. We used N-azidoacetyl-mannosamine tetraacylated as a metabolic sugar substrate to bioassemble azido-Sias on the surface of cells via the metabolic pathway of Sias de novo synthesis. These azido-Sias allow us to perform a duplex Sias-specific analysis with various fluorescent and elemental reporters such as DIBO-Alexa Fluor 647, DBCO-DOTA-Eu, and DBCO-PEG₄-BODIPY, which can be easily labeled and/or tagged through an effective copper-free bioorthogonal click reaction. Compared to the previous reported strategies, we quantified the cell surface Sias with the LODs (3σ) down to 8.9 fmol and 0.24 pmol using ¹⁵³Eu- and ¹⁰B-species unspecific isotope dilution ICPMS, in addition to their red- and green-CLSM profiling. Such a platform enables us to evaluate Sias regulation under the administration of paclitaxel, finding that 1 μM paclitaxel induced a significant Sias decrease of 67% on the surface of hepatic tumor cell SMMC-7721, while had no obvious adverse effect to that of para-carcinomatous liver cell LO2. Besides Sias, we believe that this metabolism-based click-mediated platform will provide opportunities to study other monosaccharides and their corresponding biological roles when more corresponding chemically modified sugar substrates and specific bioorthogonal reactions are developed.