In Vivo Imaging of Neoplasia

描述(申请人提供)：这项研究计划的广泛、长期目标是开发一种集成的光学分子成像策略，该策略使用荧光肽作为探针来靶向Viva中癌前(发育不良)组织的存在，并开发宏观和微观荧光仪器作为多肽检测的补充成像方法。该方法可用于监测生物标记物在小动物模型中的表达，并用于对接受筛查的人类患者进行癌症的早期检测。在本应用中，结肠腺瘤被用作异型增生的模型。其具体目标是：1)利用噬菌体展示技术对培养细胞和新鲜切除的人结肠黏膜标本进行生物扫描，识别5个候选肽；2)开发新的光学成像仪器，使用双轴共聚焦结构显示与肽结合相关的组织微结构；3)在通过激活Cre重组酶在远端结肠形成息肉的基因工程小鼠和接受常规结肠镜检查的人中，验证体内与异型增生的优先结合多肽。选择多肽作为探针是因为它们的高度多样性和小尺寸可以提供与深层组织渗透的高亲和力结合，以及它们的低免疫原性和毒性便于翻译用于临床。噬菌体展示是一种强大的组合技术，它提供了一种公正的方法来鉴定与发育不良粘膜具有亲和力的独特多肽，因为它非常适合适应与体内微环境相关的细微变化。双轴共聚焦结构提供了一种可实现远距离亚细胞分辨率的仪器，并利用离轴荧光采集克服了组织散射的影响。此外，为了与内窥镜兼容，这种设计可以缩小尺寸。直径5 mm的器械包足够小，足以穿过治疗性内窥镜中直径6 mm的器械通道。高速扫描是用微型MEMS(微型机电系统)镜进行的，它以足够的帧速率收集光学部分，以生成3D体积图像。候选多肽将局部应用于结肠腺瘤和周围正常外观的粘膜，然后进行宏观荧光成像，以定位多肽结合增加的区域，随后进行显微荧光成像，以评估多肽结合在发育不良的隐窝微结构内的空间分布。 公共卫生：拟议的研究将导致开发新的光学成像探针和仪器，可以在临床前模型中进行评估，并转化为临床上用于早期发现中空器官癌症的实用筛查工具。

DESCRIPTION (provided by applicant): The broad, long-term objectives of this research plan are to develop an integrated optical molecular imaging strategy that uses fluorescence peptides as probes to target the presence of pre-malignant (dysplastic) tissue in viva Macroscopic and microscopic fluorescence instruments are developed as complementary imaging methods for peptide detection. This methodology can be used for monitoring biomarker expression in small animal models and for the early detection of cancer in human patients undergoing screening. In this application, the colonic adenoma is used as a model for dysplasia. The specific aims are to 1) identify 5 candidate peptides using techniques of phage display for biopanning against cultured cells and freshly excised specimens of human colonic mucosa, 2) develop new optical imaging instrumentation using the dual axes confocal architecture to visualize the tissue micro architecture relevant to peptide binding, and 3) validate preferential peptide binding to dysplasia in vivo in a genetically engineered mouse that forms polyps in the distal colon by somatic activation of Cre-recombinase and in human subjects undergoing routine screening colonoscopy. Peptides are chosen for development as probes because their high diversity and small size can provide high affinity binding with deep tissue penetration, and their low risk of immunogenicity and toxicity facilitate translation for use in the clinic. Phage display is a powerful combinatorial technique that provides an unbiased approach for identifying unique peptides that exhibit affinity binding to dysplastic mucosa as is well suited to accommodate subtle changes associated with the in vivo microenvironment. The dual axes confocal architecture provides an instrument that can achieve sub-cellular resolution with long working distance and overcomes the effects of tissue scattering using off-axis fluorescence collection. Moreover, this design can be scaled down in size for endoscope compatibility. A 5 mm diameter instrument package is sufficiently small to pass through a 6 mm diameter instrument channel in a therapeutic endoscope. High speed scanning is performed with a tiny MEMS (micro-electro-mechanical systems) mirror that collects optical sections at a sufficient frame rate for generating 3D volumetric images. The candidate peptides will be topically applied to colonic adenomas and surrounding normal appearing mucosa followed by macroscopic fluorescence imaging to localize regions of increased peptide binding for subsequent microscopic fluorescence imaging to assess the spatial distribution of peptide binding within the dysplastic crypt micro architecture. Public Health: The proposed studies will result in the development of novel optical imaging probes and instruments that can be evaluated in pre-clinical models as well as translated to the clinic as practical screening tool for the early detection of cancer in hollow organs.