Multiplexed Multi-Modal Endoscopic Imaging of Cancer Biomarkers

 描述(申请人提供)：在过去的30年里，食管腺癌(EAC)的发病率在发达国家上升得比任何其他癌症都快，随着肥胖症和胃酸反流的日益普遍，这一趋势预计将继续下去。这种疾病被认为是由Barrett‘s食道引起的，目前在那里进行早期癌症检测是通过随机活检的白光内窥镜检查。这种方法容易产生抽样误差，因为高级别异型增生(HGD)和早期EAC由于形态平坦、分布斑块和患病率低，在成像上很难发现。表皮生长因子受体EGFR和ErbB2基因在EAC中扩增的频率很高，个体之间的重叠很小。相应的蛋白质靶标在细胞表面表达，并可通过使用高度特异的多肽进行体内成像。我们将开发一种多聚体，将EGFR或ErbB2的特定多肽连接起来，并连接Cy5.5，一种用于成像的明亮的近红外(NIR)荧光团。我们将使用结构模型优化多肽与这些靶点的比对，并验证竞争和siRNA击倒研究的特异性结合。我们将在流式细胞仪上表征结合亲和力和快速结合，并使用多模式近红外内窥镜验证优化的多聚体与体外人食道肿瘤标本的结合。将对荧光图像和反射图像进行比对，以校正图像视场中距离和几何形状的差异。最大化方差的阈值将用于创建二值图像。轮廓将在白光图像上定义一个“红旗”区域，以帮助医生指导组织切除。这些实验将验证仪器对靶标过度表达的敏感性。然后，我们将在动物身上进行药理毒理学研究，以确定多聚体的安全性，并向FDA提交一份调查性新药申请(IND)，以进行“人类首例”临床研究。多聚体将首先在患者身上进行评估，以确定安全性，然后进行成像研究，以验证与早期肿瘤的结合。结果将与组织学进行比较。这些目标的成功实现将为医学界提供一种综合的多模式成像方法，该方法可以检测过表达的细胞表面靶点，以指导组织切除增加癌症进展风险的病变，尽可能早地发现癌症，减少过度诊断，并区分致命性和非致命性疾病。这项合作工作将由密歇根大学的一个多学科团队进行，其中包括将开发多肽多聚体的TD Wang，将验证特定多聚体与EGFR和ErbB2结合的DG Beer，以及将进行临床研究的DK Turjo。这个经验丰富的团队最近完成了FDA批准的对食道中一种单体多肽的成像研究，这是FDA批准的第一项人类成像研究。

 DESCRIPTION (provided by applicant): Over the past 3 decades, the incidence of esophageal adenocarcinoma (EAC) has risen faster than any other cancer in developed countries, a trend that is expected to continue with increasing prevalence of obesity and acid reflux. This disease is believed to arise from Barrett's esophagus, where early cancer detection is currently performed on white light endoscopy with random biopsies. This approach is prone to sampling error because high-grade dysplasia (HGD) and early EAC are difficult to detect on imaging because of flat morphology, patchy distribution, and low prevalence. The genes for epithelial growth factor receptors, EGFR and ErbB2, are amplified in high frequency in EAC with minimal overlap among individual patients. The corresponding protein targets are expressed on the cell surface and accessible to in vivo imaging with use of highly specific peptides. We will develop a multimer that links individual peptides specific for either EGFR or ErbB2, and attach Cy5.5, a bright near-infrared (NIR) fluorophore for imaging. We will optimize the peptides on alignment to these targets using a structural model, and validate specific binding on competition and siRNA knockdown studies. We will characterize binding affinity and rapid binding on flow cytometry, and validate binding of the optimized multimer on human specimens of esophageal neoplasia ex vivo using a multi-modal NIR endoscope. Fluorescence and reflectance images will be ratioed to correct for difference in distance and geometry over the image field-of-view. The threshold that maximizes variance will be used to create a binary image. The contour will define a "red-flag" region on the white light image to help physicians guide tissue resection. These experiments will verify instrument sensitivity to target overexpression. We will then perform a pharmacology toxicology study in animals to establish multimer safety, and submit an Investigational New Drug Application (IND) to the FDA to perform a "first-in-human" clinical study. The multimer will first be evaluated in patients to establish safety and then studied on imaging to validate binding to early neoplasia. The results will be compared with histology. Successful completion of these aims will provide the medical community with an integrated multi modal imaging methodology that detects overexpressed cell surface targets to guide tissue resection of lesions that have increased risk for progressing onto cancer, detect cancer at the earliest stages possible, reduce overdiagnosis, and distinguish lethal from non-lethal disease. This collaborative work will be performed by a multi-disciplinary team at the University of Michigan, including TD Wang who will develop the peptide multimer, DG Beer who will validate specific multimer binding to EGFR and ErbB2, and DK Turgeon who will perform the clinical studies. This experienced team has recently completed an FDA-approved "first-in-human" imaging study of a monomer peptide in esophagus.