Tumor detection by imaging proteolytic activity.
Tumor detection by imaging proteolytic activity.
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DOI：
10.1158/0008-5472.can-09-1640
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发表时间：
2010-02-15
期刊：
影响因子：
11.2
通讯作者：
Craik CS
中科院分区：
文献类型：
--
作者：
Darragh MR;Schneider EL;Lou J;Phojanakong PJ;Farady CJ;Marks JD;Hann BC;Craik CS
细胞表面蛋白酶膜型丝氨酸蛋白酶1 [MT-SP1]/基质酶在上皮癌中经常上调。MT-SP1/基质酶水平与其同源抑制剂肝细胞生长因子激活因子抑制剂-1 [HAI-1]的失调表明，它是蛋白水解活性的增加，可以显著区分恶性组织与正常组织。在这里，我们使用抗体来证明MT-SP1对癌细胞有活性，并且这种活性可能是体内肿瘤检测的目标。对MT-SP1阳性的人癌细胞系MCF-7、HT29、LNCaP和MDA-MB-468的蛋白水解活性分析表明，抑制重组催化MT-SP1的抗体能够结合并抑制全长酶。对mt - sp1阴性乳腺癌细胞株MDA-MB-231、COLO 320DM和HT1080进行同样的实验，未发现蛋白水解受到抑制。然后荧光显微镜确认标记抗体在mt - sp1阳性细胞表面的定位。为了评估这些抗体作为体内靶向MT-SP1活性的探针，将0.7-2纳米摩尔荧光标记抗体给予异种移植小鼠癌症模型。抗体定位于MT-SP1阳性的MCF-7和MCF-7/Luc+肿瘤（n=3），允许可视化MT-SP1活性。在MT-SP1阴性的MDA-MD-231/Luc阳性肿瘤中未观察到荧光（n=2），这表明MT-SP1活性是上皮性癌症的一种新的生物标志物，这些抗体为体内检测MT-SP1活性提供了一种非侵入性方法。
The cell surface protease membrane-type serine protease 1 [MT-SP1]/matriptase is often upregulated in epithelial cancers. A dysregulation in MT-SP1/matriptase levels with respect to its cognate inhibitor hepatocyte growth factor activator inhibitor-1 [HAI-1] suggests that it is an increase in proteolytic activity that significantly differentiates malignant from normal tissue. Here we use antibodies to demonstrate that MT-SP1 is active on cancer cells and that this activity may be targeted for tumor detection in vivo. A proteolytic activity assay with the MT-SP1-positive human cancer cell lines MCF-7, HT29, LNCaP, and MDA-MB-468 showed that the antibodies, which inhibit recombinant catalytic MT-SP1, are able to bind and inhibit the full-length enzyme. The same experiment with the MT-SP1-negative breast cancer cell lines MDA-MB-231, COLO 320DM and HT1080 showed no inhibition of proteolysis. Fluorescent microscopy then confirmed localization of labeled antibodies to the surface of MT-SP1-positive cells. To evaluate these antibodies as probes for targeting MT-SP1 activity in vivo, 0.7-2 nanomoles of fluorescently labeled antibodies were administered to xenograft mouse cancer models. The antibodies localized to the MT-SP1-positive MCF-7 and MCF-7/Luc+ tumors (n=3), permitting visualization of MT-SP1 activity. Fluorescence was not observed in MT-SP1-negative MDA-MD-231/Luc+ tumors (n=2), suggesting that MT-SP1 activity is a novel biomarker for epithelial cancer and these antibodies provide a non-invasive method for detecting this activity in vivo.