Optical labeling of tumor boundaries

描述(由申请人提供)： 肿瘤边界的检测和监测对于癌症的有效治疗和提高我们对癌症进展的了解至关重要。SRI国际(SRI)合作者最近的研究已经确定了一种酶，组织转谷氨酰胺酶(TTG)，它划分了正常组织和损伤/恶性组织之间的边界。SRI假设这种酶的活性可以利用光学检测来勾勒出肿瘤的轮廓。为了验证这一假设，SRI提出了一个具有以下具体目标的R21项目： (1)利用光学标记的tTG底物改进用于体外分析和体内成像的光学仪器。我们将修改荧光显微镜和体内成像系统的设计，为标记的底物使用合适的激发和发射波长。 (2)合成和评价基于血浆蛋白的光学标记tTG底物。TTG作用于底物后，将与适合于近红外活体成像的菁染料偶联。标记的底物将在血管内皮细胞系的体外实验中进行评估。 (3)用红外成像法在体内检测标记底物的活性。这项成像将在伤口愈合模型、底物清除模型和大鼠肿瘤模型上进行。 从长远来看，我们计划使用标记的tTG底物来回答有关肿瘤进展的基本问题，并开发一种临床划定肿瘤边界的方法，适合在活体组织检查或肿瘤切除期间用作术中诊断。这项技术对血栓成像也有价值。

DESCRIPTION (provided by applicant): Detection and monitoring of tumor boundaries are vital for the effective treatment of cancer and for improving our understanding of cancer progression. Recent studies by SRI International's (SRI's) collaborators have identified an enzyme, tissue transglutaminase (tTG) that demarcates the border between normal and injured/malignant tissue. SRI hypothesizes that the activity of this enzyme can be exploited to outline tumors using optical detection. To test this hypothesis, SRI proposes an R21 project with the following specific aims: (1) Modify optical instrumentation for in vitro assays and in vivo imaging using optically labeled tTG substrates. We will modify a fluorescence microscope and in vivo imaging system design to use appropriate excitation and emission wavelengths for the labeled substrates. (2) Synthesize and evaluate plasma protein-based tTG substrates with optical labels. Substrates acted on by tTG will be conjugated with cyanine dyes suitable for near-infrared in vivo imaging. Labeled substrate will be evaluated in an in vitro assay on an endothelial cell line. (3) Test activity on labeled substrates in vivo using infrared imaging. This imaging will be performed on a wound-healing model, a substrate clearance model, and a tumor model in rats. In the longer term, we plan to use labeled tTG substrates to answer basic questions regarding tumor progression and to develop a methodology for clinical demarcation of tumor boundaries suitable for use as an intraoperative diagnostic during biopsy or tumor removal. The technique would also be of value for imaging thrombi.