Detection of dysplastic intestinal adenomas using enzyme-sensing molecular beacons in mice
Detection of dysplastic intestinal adenomas using enzyme-sensing molecular beacons in mice
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DOI：
10.1053/gast.2002.30990
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发表时间：
2002-02-01
期刊：
影响因子：
29.4
通讯作者：
Weissleder, R
中科院分区：
文献类型：
--
作者：
Marten, K;Bremer, C;Weissleder, R
背景与目的：蛋白酶在肿瘤生长和侵袭的发病机制中发挥着关键作用。本研究评估了发育不良腺瘤性息肉中组织蛋白酶 B 的表达。方法：老年ApC(Min/+)小鼠作为家族性腺瘤性息肉病的实验模型。 4 个实验组包括 (a) 注射了新型可激活组织蛋白酶 B 传感近红外荧光 (NIRF) 成像探针的动物； (b) 注射了非特异性 NIRF 的动物； (c) 未注射的对照动物； (d) 注射组织蛋白酶 B 探针的非 ApC(Min/+) 小鼠。通过免疫组织化学、蛋白质印迹、逆转录聚合酶链反应和光学成像对病变进行分析。结果：组织蛋白酶 B 在腺瘤性息肉中持续过度表达。当小鼠静脉注射组织蛋白酶报告探针时，肠腺瘤发出高荧光，表明组织蛋白酶 B 酶活性较高。即使是微小的腺瘤也可以通过荧光成像轻松检测到，但不能通过光成像检测到。可检测到的最小病变直径为 50 微米。吲哚菁绿和/或未注射组中的腺瘤在背景上方几乎检测不到。结论：目前的实验研究表明，组织蛋白酶 B 在腺瘤性息肉病小鼠模型中表达上调。组织蛋白酶 B 活性可用作生物标志物，以轻松识别此类病变，特别是与正常相邻粘膜进行对比时。该检测技术可适用于内窥镜检查或断层光学成像方法，用于筛查可疑病变，并可能用于体内分子分析。
Background & Aims: Proteases play key roles in the pathogenesis of tumor growth and invasion. This study assesses the expression of cathepsin B in dysplastic adenomatous polyps. Methods: Aged ApC(Min/+) mice served as an experimental model for familial adenomatous polyposis. The 4 experimental groups consisted of (a) animals injected with a novel activatable, cathepsin B sensing near infrared fluorescence (NIRF) imaging probe; (b) animals injected with a nonspecific NIRF; (c) uninjected control animals; and (d) non-ApC(Min/+) mice injected with the cathepsin B probe. Lesions were analyzed by immunohistochemistry, Western blotting, reverse transcription-polymerase chain reaction, and optical imaging. Results: Cathepsin B was consistently overexpressed in adenomatous polyps. When mice were injected intravenously with the cathepsin reporter probe, intestinal adenomas became highly fluorescent indicative of high cathepsin B enzyme activity. Even microscopic adenomas were readily detectable by fluorescence, but not light, imaging. The smallest lesion detectable measured 50 mum in diameter. Adenomas in the indocyanine green and/or noninjected group were only barely detectable above the background. Conclusions: The current experimental study shows that cathepsin B is up-regulated in a mouse model of adenomatous polyposis. Cathepsin B activity can be used as a biomarker to readily identify such lesions, particularly when contrasted against normal adjacent mucosa. This detection technology can be adapted to endoscopy or tomographic optical imaging methods for screening of suspicious lesions and potentially for molecular profiling in vivo.