Isolation and Assessment of Blood-Circulating Cancer Exosomes with LSS and SERS Lab on a Chip Optical Spectroscopic Instrument

项目摘要 从原发肿瘤进入外周循环，循环中的肿瘤细胞(CTCs)受到 它们在血液中的浓度极低。相比之下，肿瘤细胞分泌的分子标志物 进入血管系统的物质以更高的浓度存在，并可能为 癌细胞生物学和早期发现、进展和转移的预测性生物标志物。这些 标志物，包括可溶性蛋白质、无细胞DNA(CfDNA)、循环微泡和外切体 已被证明包含关于通常难以接近的肿瘤的分子状态的有价值的信息 网站。不幸的是，血液中发现的可溶性蛋白质的来源无法确定，导致 虽然cfDNA明显更具特异性，但高假阳性率往往反映死亡或凋亡 细胞。胞外体是一种来源于内吞的小的膜小泡，作为一种极具潜力的 可用于癌症早期检测和监测的生物标记物，因为它们具有独特的特性，包括 它们在生物体液中的稳定性以及它们被有效分离的潜力。癌细胞释放更多 外切体比正常细胞和肿瘤细胞分泌的外切体都能促进肿瘤进展， 生存、侵袭和血管生成。 在本申请中，我们建议开发一种光学光谱技术，它结合了 光散射光谱(LSS)和表面增强拉曼光谱(SERS) 用于早期癌症检测的血液循环癌症外显体的严格分离和评估 快速、廉价的芯片实验室系统。如此应用程序中所示，不仅LSS可以分离 外体和微囊的能力目前还不具备，但它也可以分化 各种类型的外切体起源于消化道的不同器官，而SERS能够 分化同一器官的癌细胞和正常细胞分泌的外切体。

Project Summary Shed into the peripheral circulation from a primary tumor, circulating tumor cells (CTCs) are limited by their extremely sparse concentrations in blood. In contrast, molecular markers secreted by tumor cells into the vasculature are present in much higher concentrations and could provide important insight on cancer cell biology and predictive biomarkers for early detection, progression and metastasis. These markers, including soluble proteins, cell-free DNA (cfDNA), and circulating microvesicles and exosomes have been shown to contain valuable information on the molecular state of often difficult to access tumor sites. Unfortunately, the source of the soluble proteins found in blood cannot be determined, resulting in the high false-positive rates, while significantly more specific cfDNA often reflect the dying or apoptotic cells. Exosomes, small membrane vesicles of endocytic origin, show the greatest potential as an easily accessible biomarker for early cancer detection and monitoring due to their unique properties, including their stability in biological fluids and their potential to be efficiently isolated. Cancer cells release more exosomes than normal cells and exosomes secreted from tumor cells can promote tumor progression, survival, invasion and angiogenesis. In this application we propose to develop an optical spectroscopic technique, which combines light scattering spectroscopy (LSS) and surface enhanced Raman spectroscopy (SERS) for highly rigorous isolation and assessment of blood-circulating cancer exosomes for early cancer detection in a rapid and inexpensive lab-on-a-chip system. As it is shown in this application, not only LSS can separate exosomes from microvesicles, the capability not available at the moment, but it also can differentiate various types of exosomes originated in different organs of the digestive tract, while SERS is capable of differentiating exosomes secreted by cancerous and normal cells of the same organ.