Desorption Electrospray Ionization Mass Spectrometry Imaging in Clinical Diagnost

描述（由申请人提供）：将评估基于质谱（MS）的组织诊断方法，以区分肾癌，膀胱癌和睾丸癌的存在，类型和分级。基于溶剂的解吸电喷雾电离（DESI）质谱法将用于直接检查组织，由此产生的脂质衍生离子的分布将用于表征组织的疾病状态。通过建立与不同疾病状态和等级的组织相关的具有代表性的脂质离子强度模式的数据库，将有助于这一点。独立的组织特征将通过组织病理学的标准方法进行。多元统计工具将用于评估DESI- ms成像数据，软件工具将开发DESI分子图像与H&E染色光学图像的关联。（这方面的工作将由统计学家和生物信息学专家奥尔加·维特克教授领导。）特别要注意的是，DESI溶剂在形态学上是非破坏性的，因此可以在手术工作流程的任何一点插入DESI成像。这项工作的假设基础是，组织中脂质分布提供的分子信息是恶性肿瘤的诊断，并补充了使用组织病理学对肿瘤边缘的评估。为了测试DESI- ms作为外科诊断工具的能力，我们将在印第安纳大学医学院病理实验室找到一台配备DESI的质谱仪。在那里，将与病理学家（Liang Cheng博士）合作，使用外科医生（Timothy Masterson博士）提供的样本进行DESI方法的测试。实验将分三个阶段进行：a)在不干扰外科手术中使用的标准程序的情况下，对切除组织进行离线分析。组织将被喷上溶剂，质谱将被评估以达到诊断（癌症及其等级；或正常）。这些结果将与标准组织病理学诊断结果进行比较。b)与标准病理检查并行的在线组织切片成像将用于验证DESI-MS在手术时间尺度上产生病理信息的能力。这些实验将用于验证/无效DESI-MS成像作为临床组织分析工作流程中肿瘤边缘评估的首要步骤。c)手术过程中切除组织的快速在线DESI分析将用于检查切除组织表面是否没有肿瘤边缘。通过使用索引系统，任何未完全切除的癌组织的位置将在适合手术修复的时间尺度上定位。为了准备将来在手术套件中使用质谱的发展，小型质谱仪的性能将得到改进，以便在单位分辨率下进行1000 Da的脂质分析。

DESCRIPTION (provided by applicant): A method of tissue diagnosis based on mass spectrometry (MS) will be evaluated to distinguish the presence, type and grade of kidney, bladder and testicular cancers. The solvent-based method of desorption electrospray ionization (DESI) MS will be used to examine tissue directly and the resulting distribution of lipid-derived ions will be used to characterize the disease state of the tissue. This will be facilitated by building a data base of representative patterns of lipid ion intensities associated with tissue of different disease states and grades. Independent tissue characterization will be made by the standard methods of histopathology. Multivariate statistical tools will be used to evaluate the DESI-MS imaging data and software tools will be developed to correlate DESI molecular images with H&E stained optical images. (This aspect of the work will be led by Prof. Olga Vitek, a statistician and specialist in bioinformatics.) Special attention will be given to DESI solvents tht are morphologically non-destructive, so allowing DESI imaging to be inserted at any point in the surgical work-flow. The hypothesis underlying this effort is that the molecular information provided on lipid distributions in tissue is diagnostic of malignancy and complements the evaluation of tumor margins using histopathology. To test the capabilities of DESI-MS as a diagnostic tool for surgical applications, we will locate a DESI- equipped mass spectrometer in an Indiana University School of Medicine pathology laboratory. There, tests of the DESI method will be made in collaboration with a pathologist (Dr. Liang Cheng) using samples provided by a surgeon (Dr. Timothy Masterson). The experiments will occur in three stages: a) Off-line analysis of excised tissue without interfering with standard procedures used in surgical intervention. Tissue will be sprayed with a solvent and the mass spectra will be evaluated to reach a diagnosis (cancer, and its grade; or normal). These results will be compared with diagnoses obtained by standard histopathology. b) On-line tissue section imaging in parallel with standard pathology examination will be used to validate the capability of DESI-MS to yield pathological information on the time-scale of the surgery. These experiments will be used to validate/invalidate DESI-MS imaging as the primary step in clinical tissue- analysis workflow for tumor margin assessment. c) Rapid on-line DESI analysis of excised tissue during surgery will be used to check that the surface of resected tissue is clean of tumor margins. By using an indexing system the position of any incompletely removed cancerous tissue will be localized on a time scale suitable for surgical remediation. In preparation for future developments in which MS is utilized in the surgical suite, the performance of a small mass spectrometer will be improved to allow lipid analysis to mass 1000 Da at unit resolution.