An enzymatically activated fluorescence probe for targeted tumor imaging
An enzymatically activated fluorescence probe for targeted tumor imaging
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DOI：
10.1021/ja067710a
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发表时间：
2007-04-04
影响因子：
15
通讯作者：
Urano, Yasuteru
中科院分区：
文献类型：
--
作者：
Kamiya, Mako;Kobayashi, Hisataka;Urano, Yasuteru
-半乳糖苷酶是一种广泛使用的报告酶，但尽管有几种底物可用于体外检测，但其在体内光学成像中的应用仍然是一个挑战。为了获得一种适合体内使用的探针，我们修改了之前开发的可激活荧光探针tg - β Gal （J. Am.）。化学。光子学报，2005,27,4888-4894)，以光化学和光物理实验为基础。这种新的探针，am - tg - β Gal，在与β -半乳糖苷酶反应时提供了显著的荧光增强，并且普遍存在的细胞内酯酶进一步水解酯部分提供了一种亲水性产物，该产物在细胞内保留得很好，而不会失去荧光。我们使用小鼠肿瘤模型来评估AM-TG-beta Gal的实际效用，在确认模型中的肿瘤可以用亲和素- β -半乳糖苷酶偶联物标记。该结合物在体内给予小鼠，随后给予AM-TG-beta Gal，随后的离体荧光成像清晰地显示了小至200 μ m的腹膜内肿瘤。该策略具有潜在的临床应用，例如在视频辅助腹腔镜肿瘤切除术中。
beta-Galactosidase is a widely used reporter enzyme, but although several substrates are available for in vitro detection, its application for in vivo optical imaging remains a challenge. To obtain a probe suitable for in vivo use, we modified our previously developed activatable fluorescence probe, TG-beta Gal (J. Am. Chem. Soc. 2005, 127, 4888-4894), on the basis of photochemical and photophysical experiments. The new probe, AM-TG-beta Gal, provides a dramatic fluorescence enhancement upon reaction with beta-galactosidase, and further hydrolysis of the ester moiety by ubiquitous intracellular esterases affords a hydrophilic product that is well retained within the cells without loss of fluorescence. We used a mouse tumor model to assess the practical utility of AM-TG-beta Gal, after confirming that tumors in the model could be labeled with an avidin-beta-galactosidase conjugate. This conjugate was administered to the mice in vivo, followed by AM-TG-beta Gal, and subsequent ex vivo fluorescence imaging clearly visualized intraperitoneal tumors as small as 200 mu m. This strategy has potential clinical application, for example, in video-assisted laparoscopic tumor resection.