Fluorescent and Chemiluminescent Cyclooctyne Probes for Imaging Glycosylation

描述（由申请人提供）：癌细胞显示异常的糖基化细胞表面，通常与癌症行为相关。然而，癌细胞为何以及何时表现出异常糖基化的问题在很大程度上仍然没有答案，因为目前的分析工具无法观察到糖基化的快速变化。我计划开发一个成像平台能够显示癌症糖基化的空间和时间分辨率。所提出的策略将利用环炔探针（无铜点击反应）与非天然细胞表面叠氮标记的糖的化学反应，将一种显像剂附着在癌细胞上。新探针的创新之处在于叠氮化物成像的灵敏度和特异性；这个

DESCRIPTION (provided by applicant): Cancer cells display unusually glycosylated cell surfaces that are often correlated to cancer behavior. However, the question of why and when cancer cells exhibit aberrant glycosylation remains largely unanswered because current analytical tools cannot observe rapid glycosylation changes. I plan to develop an imaging platform able to reveal cancer glycosylation with both spatial and temporal resolution. The proposed strategy will use the chemical reaction of a cyclooctyne probe (copper-free click reaction) with an unnatural cell surface azide-labeled sugar to attach a visualizing agent to the cancer cell. The innovation of the new probes is sensitivity and specificity for azide imaging; the probes were designed to only form the visualizing agent after reaction with azide. This will increase imaging sensitivity because off-target binding and residual probe will not contribute to background noise. Two generations of cyclooctyne probes will be developed with two distinct visualizing agents: a fluorescent smart probe (Aim 1) and a chemiluminescent probe (Aim 2). The fluorescent cyclooctyne probe will be used to quantify sialic acid content on the surface of Chinese hamster ovary cells (Aim 3). The chemiluminescent cyclooctyne probe will be used to measure the effectiveness of a known sialyl transferase inhibitor with potential as an anti-cancer metastasis agent. The long-term goal of this project is to develop an imaging platform capable of elucidating how glycosylation affects cancer behavior in model organisms. PUBLIC HEALTH RELEVANCE: The proposed research in this application will advance the chemical technologies used to study cellular sugar molecules related to cancer progression. Understanding how sugar molecules are involved in the progression of cancer may ultimately translate into new prognostic and therapeutic strategies. The first step toward gaining this understanding is to develop the chemical imaging tools needed to observe specific sugar molecules in tumors.