Fluorescence-guided cancer surgery can dramatically improve recurrence rates and postoperative quality of life of patients by accurately distinguishing the boundary between normal and cancer tissues during surgery, thereby minimizing excision of normal tissue. One promising target in early stage cancer is fragile histidine triad (FHIT), a cancer suppressor protein with dinucleoside triphosphate hydrolase activity. In this study, we have developed fluorescence probes containing a nucleoside diphosphate moiety, which dramatically improves the reactivity and specificity for FHIT, and a moderately lipophilic ester moiety to increase the membrane permeability. The ester moiety is cleaved by ubiquitous intracellular esterases, and then, FHIT in the cells specifically cleaves nucleoside monophosphate. The remaining phosphate moiety is rapidly cleaved by ubiquitous intracellular phosphatases to release the fluorescent dye. We confirmed that this probe can detect FHIT activity in living cells. A comprehensive evaluation of the effects of various ester moieties revealed that probes with CLogP = 5–7 showed good membrane permeability and were good substrates of the target enzyme; these findings may be helpful in the rational design of other multiple phosphate-containing probes targeting intracellular enzymes.

中文翻译：

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核苷二磷酸轴承脆性组氨酸三联体成像荧光探针的开发，具有良好的疏水性，用于细胞内递送

荧光引导的癌症手术通过在手术过程中准确区分正常组织和癌组织之间的边界，从而最大限度地减少正常组织的切除，可以显着提高患者的复发率和术后生活质量。早期癌症的一个有希望的目标是脆性组氨酸三联体 (FHIT)，这是一种具有三磷酸二核苷水解酶活性的抑癌蛋白。在这项研究中，我们开发了包含核苷二磷酸部分的荧光探针，它显着提高了 FHIT 的反应性和特异性，以及适度亲脂性酯部分以增加膜通透性。酯部分被普遍存在的细胞内酯酶切割，然后，细胞中的 FHIT 特异性切割核苷一磷酸。剩余的磷酸盐部分被普遍存在的细胞内磷酸酶迅速切割，释放出荧光染料。我们证实该探针可以检测活细胞中的 FHIT 活性。对各种酯基团影响的综合评估表明，CLogP = 5-7 的探针显示出良好的膜渗透性，是目标酶的良好底物；这些发现可能有助于合理设计其他多种靶向细胞内酶的含磷酸盐探针。